query: what is the colour of gram positive bacteria

pos: Gram stain from the primary stain. Gram-positive bacteria retain the crystal violet dye, and thus are stained violet, while the Gram-negative bacteria do not; after washing, a counterstain is added (commonly safranin or fuchsine) that will stain these Gram-negative bacteria a pink color. Both Gram-positive bacteria and Gram-negative bacteria pick up the counterstain. The counterstain, however, is unseen on Gram-positive bacteria because of the darker crystal violet stain. The Gram stain is almost always the first step in the preliminary identification of a bacterial organism. While Gram staining is a valuable diagnostic tool in both clinical and research settings, not all bacteria

pos: Gram-positive bacteria Gram-positive bacteria Gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their cell wall. Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through a microscope. This is because the thick peptidoglycan layer in the bacterial cell wall retains the stain after it is washed away from the rest of the sample, in the decolorization stage of the test. Gram-negative bacteria cannot retain the violet stain after the decolorization step;

pos: Gram stain from the primary stain. Gram-positive bacteria retain the crystal violet dye, and thus are stained violet, while the Gram-negative bacteria do not; after washing, a counterstain is added (commonly safranin or fuchsine) that will stain these Gram-negative bacteria a pink color. Both Gram-positive bacteria and Gram-negative bacteria pick up the counterstain. The counterstain, however, is unseen on Gram-positive bacteria because of the darker crystal violet stain. The Gram stain is almost always the first step in the preliminary identification of a bacterial organism. While Gram staining is a valuable diagnostic tool in both clinical and research settings, not all bacteria

pos: MacConkey agar fermenting. MacConkey agar MacConkey agar is an indicator, a selective and differential culture medium for bacteria designed to selectively isolate Gram-negative and enteric (normally found in the intestinal tract) bacilli and differentiate them based on lactose fermentation. The crystal violet and bile salts inhibit the growth of gram-positive organisms which allows for the selection and isolation of gram-negative bacteria. Enteric bacteria that have the ability to ferment lactose can be detected using the carbohydrate lactose, and the pH indicator neutral red. It contains bile salts (to inhibit most Gram-positive bacteria), crystal violet dye (which also inhibits certain Gram-positive bacteria), neutral

pos: MacConkey agar MacConkey agar MacConkey agar is an indicator, a selective and differential culture medium for bacteria designed to selectively isolate Gram-negative and enteric (normally found in the intestinal tract) bacilli and differentiate them based on lactose fermentation. The crystal violet and bile salts inhibit the growth of gram-positive organisms which allows for the selection and isolation of gram-negative bacteria. Enteric bacteria that have the ability to ferment lactose can be detected using the carbohydrate lactose, and the pH indicator neutral red. It contains bile salts (to inhibit most Gram-positive bacteria), crystal violet dye (which also inhibits certain Gram-positive bacteria), neutral red

pos: Atypical bacteria is strictly caused by atypical bacteria, for this disease can also have a fungal, protozoan or viral cause. Atypical bacteria Atypical bacteria are bacteria that do not color with gram-staining but rather remain colorless: they are neither Gram-positive nor Gram-negative. These include the Chlamydiaceae, Legionella and the Mycoplasmataceae (including mycoplasma and ureaplasma); the Rickettsiaceae are also often considered atypical. Gram-positive bacteria have a thick peptidoglycan layer in their cell wall, which retains the crystal violet during Gram staining, resulting in a purple color. Gram-negative bacteria have a thin peptidoglycan layer which does not retain the crystal violet, so when safranin

pos: Atypical bacteria Atypical bacteria Atypical bacteria are bacteria that do not color with gram-staining but rather remain colorless: they are neither Gram-positive nor Gram-negative. These include the Chlamydiaceae, Legionella and the Mycoplasmataceae (including mycoplasma and ureaplasma); the Rickettsiaceae are also often considered atypical. Gram-positive bacteria have a thick peptidoglycan layer in their cell wall, which retains the crystal violet during Gram staining, resulting in a purple color. Gram-negative bacteria have a thin peptidoglycan layer which does not retain the crystal violet, so when safranin is added during the process, they stain red. The Chlamydiaceae and Mycoplasmataceae lack a peptidoglycan layer so do

pos: Cell envelope (with a few exceptions e.g. intracellular parasites such as "Mycoplasma") contain peptidoglycan, not all cell walls have the same overall structures. This is notably expressed through the classification into gram positive and gram negative bacteria. The gram-positive cell wall is characterised by the presence of a very thick peptidoglycan layer, which is responsible for the retention of the crystal violet dyes during the Gram staining procedure. It is found exclusively in organisms belonging to the Actinobacteria (or high %G+C gram-positive organisms) and the Firmicutes (or low %G+C gram-positive organisms). Bacteria within the Deinococcus-Thermus group may also exhibit gram-positive staining behaviour

pos: Bacterial cell structure cell walls are thick and the peptidoglycan ( also known as "murein") layer constitutes almost 95% of the cell wall in some gram-positive bacteria and as little as 5-10% of the cell wall in gram-negative bacteria. The gram-positive bacteria take up the crystal violet dye and are stained purple. The cell wall of some gram-positive bacteria can be completely dissolved by lysozymes which attacks the bonds between N-acetylmuramic acid and N-acetylglucosamine. In other gram-positive bacteria, such as "Staphylococcus aureus", the walls are resistant to the action of lysozymes. They have O-acetyl groups on carbon-6 of some muramic acid residues. The

pos: Gram-positive bacteria alcohol used in this stage degrades the outer membrane of gram-negative cells, making the cell wall more porous and incapable of retaining the crystal violet stain. Their peptidoglycan layer is much thinner and sandwiched between an inner cell membrane and a bacterial outer membrane, causing them to take up the counterstain (safranin or fuchsine) and appear red or pink. Despite their thicker peptidoglycan layer, gram-positive bacteria are more receptive to certain cell wall targeting antibiotics than gram-negative bacteria, due to the absence of the outer membrane. In general, the following characteristics are present in gram-positive bacteria: Only some species have

pos: Eubacterium Eubacterium Eubacterium is a genus of Gram-positive bacteria in the family Eubacteriaceae. These bacteria are characterised by a rigid cell wall. They may either be motile or nonmotile. If motile, they have a flagellum. A typical flagellum consists of a basal body, filament, and hook. The long filament is the organ which helps eubacteria move. Gram-positive bacteria have a thick proteoglycan layer and take up violet Gram stain (whereas Gram-negative bacteria have a thinner proteoglycan layer which is surrounded by a layer of immune response-inducing lipopolysaccharide, and do not take up Gram stain). Species from this genus have been isolated

pos: Eubacterium from women with bacterial vaginosis. List of bacterial vaginosis microbiota Eubacterium Eubacterium is a genus of Gram-positive bacteria in the family Eubacteriaceae. These bacteria are characterised by a rigid cell wall. They may either be motile or nonmotile. If motile, they have a flagellum. A typical flagellum consists of a basal body, filament, and hook. The long filament is the organ which helps eubacteria move. Gram-positive bacteria have a thick proteoglycan layer and take up violet Gram stain (whereas Gram-negative bacteria have a thinner proteoglycan layer which is surrounded by a layer of immune response-inducing lipopolysaccharide, and do not take

pos: Gram stain its peptidoglycan. The decolorization step is critical and must be timed correctly; the crystal violet stain is removed from both gram-positive and negative cells if the decolorizing agent is left on too long (a matter of seconds). After decolorization, the gram-positive cell remains purple and the gram-negative cell loses its purple color. Counterstain, which is usually positively charged safranin or basic fuchsine, is applied last to give decolorized gram-negative bacteria a pink or red color. Gram-positive bacteria generally have a single membrane ("monoderm") surrounded by a thick peptidoglycan. This rule is followed by two phyla: "Firmicutes" (except for the classes

pos: Gram-negative bacteria disease. The adjectives "Gram-positive" and "Gram-negative" derive from the surname of Hans Christian Gram, a Danish bacteriologist; as eponymous adjectives, their initial letter can be either capital "G" or lower-case "g", depending on which style guide (e.g., that of the CDC), if any, governs the document being written. This is further explained at "Gram staining § Orthographic note". Gram-negative bacteria Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the gram-staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall sandwiched between an inner

pos: Staining lacks the secondary membrane and lipopolysaccharide layer found in Gram-negative bacteria. On most Gram-stained preparations, Gram-negative organisms appear red or pink because they are counterstained. Because of presence of higher lipid content, after alcohol-treatment, the porosity of the cell wall increases, hence the CVI complex (crystal violet – iodine) can pass through. Thus, the primary stain is not retained. Also, in contrast to most Gram-positive bacteria, Gram-negative bacteria have only a few layers of peptidoglycan and a secondary cell membrane made primarily of lipopolysaccharide. Endospore staining is used to identify the presence or absence of endospores, which make bacteria very

pos: Staining staining is a mild technique that may not destroy the microorganisms, and is therefore unsuitable for studying pathogens. Gram staining is used to determine gram status to classify bacteria broadly. It is based on the composition of their cell wall. Gram staining uses crystal violet to stain cell walls, iodine as a mordant, and a fuchsin or safranin counterstain to mark all bacteria. Gram status is important in medicine; the presence or absence of a cell wall changes the bacterium's susceptibility to some antibiotics. Gram-positive bacteria stain dark blue or violet. Their cell wall is typically rich with peptidoglycan and

neg: L-form bacteria since they are not derived from bacteria that normally have cell walls. Bacterial morphology is determined by the cell wall. Since the L-form has no cell wall, its morphology is different from that of the strain of bacteria from which it is derived. Typical L-form cells are spheres or spheroids. For example, L-forms of the rod-shaped bacterium "Bacillus subtilis" appear round when viewed by phase contrast microscopy or by transmission electron microscopy. Although L-forms can develop from Gram-positive as well as from Gram-negative bacteria, in a Gram stain test, the L-forms always colour Gram-negative, due to the lack of a

neg: Peptidoglycan pressure of the cytoplasm. Peptidoglycan is also involved in binary fission during bacterial cell reproduction. The peptidoglycan layer is substantially thicker in Gram-positive bacteria (20 to 80 nanometers) than in Gram-negative bacteria (7 to 8 nanometers). Peptidoglycan forms around 90% of the dry weight of Gram-positive bacteria but only 10% of Gram-negative strains. Thus, presence of high levels of peptidoglycan is the primary determinant of the characterisation of bacteria as Gram-positive. In Gram-positive strains, it is important in attachment roles and serotyping purposes. For both Gram-positive and Gram-negative bacteria, particles of approximately 2 nm can pass through the peptidoglycan. The

neg: Gram-positive bacteria (gram-negative) bacteria. The diderm bacteria can also be further differentiated between simple diderms lacking lipopolysaccharide, the archetypical diderm bacteria where the outer cell membrane contains lipopolysaccharide, and the diderm bacteria where outer cell membrane is made up of mycolic acid. In general, gram-positive bacteria are monoderms and have a single lipid bilayer whereas gram-negative bacteria are diderms and have two bilayers. Some taxa lack peptidoglycan (such as the domain Archaea, the class Mollicutes, some members of the Rickettsiales, and the insect-endosymbionts of the Enterobacteriales) and are gram-variable. This, however, does not always hold true. The "Deinococcus-Thermus" bacteria have gram-positive stains,

neg: Clarithromycin second line agent in Lyme disease and toxoplasmosis. It may also be used to prevent bacterial endocarditis in those who cannot take penicillin. It is effective against upper and lower respiratory tract infections, skin and soft tissue infections and helicobacter pylori infections associated with duodenal ulcers. Aerobic Gram-positive bacteria Aerobic Gram-negative bacteria Helicobacter Mycobacteria Mycobacterium avium complex consisting of: Other bacteria Safety and effectiveness of clarithromycin in treating clinical infections due to the following bacteria have not been established in adequate and well-controlled clinical trials: Aerobic Gram-positive bacteria Aerobic Gram-negative bacteria Anaerobic Gram-positive bacteria Anaerobic Gram-negative bacteria The most common

neg: Periplasm Periplasm The periplasm is a concentrated gel-like matrix in the space between the inner cytoplasmic membrane and the bacterial outer membrane called the "periplasmic space" in gram-negative bacteria. Using cryo-electron microscopy it has been found that a much smaller periplasmic space is also present in gram-positive bacteria. The periplasm may constitute up to 40% of the total cell volume of gram-negative bacteria, but is a much smaller percentage in gram-positive bacteria. Although the bacteria are conventionally divided into two main groups—gram-positive and gram-negative, based upon their Gram-stain retention property—this classification system is ambiguous as it can refer to three distinct

neg: Gram-positive bacteria a capsule, usually consisting of polysaccharides. Also, only some species are flagellates, and when they do have flagella, have only two basal body rings to support them, whereas gram-negative have four. Both gram-positive and gram-negative bacteria commonly have a surface layer called an S-layer. In gram-positive bacteria, the S-layer is attached to the peptidoglycan layer. Gram-negative bacteria's S-layer is attached directly to the outer membrane. Specific to gram-positive bacteria is the presence of teichoic acids in the cell wall. Some of these are lipoteichoic acids, which have a lipid component in the cell membrane that can assist in anchoring the

neg: Bacteria alternative gram-positive arrangement. These differences in structure can produce differences in antibiotic susceptibility; for instance, vancomycin can kill only gram-positive bacteria and is ineffective against gram-negative pathogens, such as "Haemophilus influenzae" or "Pseudomonas aeruginosa". Some bacteria have cell wall structures that are neither classically gram-positive or gram-negative. This includes clinically important bacteria such as "Mycobacteria" which have a thick peptidoglycan cell wall like a gram-positive bacterium, but also a second outer layer of lipids. In many bacteria, an S-layer of rigidly arrayed protein molecules covers the outside of the cell. This layer provides chemical and physical protection for the cell

neg: Bacteria bacteria, that classify bacteria into gram-positive bacteria and gram-negative bacteria. The names originate from the reaction of cells to the Gram stain, a long-standing test for the classification of bacterial species. Gram-positive bacteria possess a thick cell wall containing many layers of peptidoglycan and teichoic acids. In contrast, gram-negative bacteria have a relatively thin cell wall consisting of a few layers of peptidoglycan surrounded by a second lipid membrane containing lipopolysaccharides and lipoproteins. Most bacteria have the gram-negative cell wall, and only the Firmicutes and Actinobacteria (previously known as the low G+C and high G+C gram-positive bacteria, respectively) have the

neg: Gram stain Gram, but are derived from such forms. Some bacteria have cell walls which are particularly adept at retaining stains. These will appear positive by Gram stain even though they are not closely related to other gram-positive bacteria. These are called acid fast bacteria, and can only be differentiated from other gram-positive bacteria by special staining procedures. Gram-negative bacteria generally possess a thin layer of peptidoglycan between two membranes ("diderms"). Most bacterial phyla are gram-negative, including the cyanobacteria, green sulfur bacteria, and most Proteobacteria (exceptions being some members of the "Rickettsiales" and the insect-endosymbionts of the "Enterobacteriales"). Some bacteria, after staining

neg: Gram-positive bacteria Of these two structurally distinct groups of bacteria, monoderms are indicated to be ancestral. Based upon a number of observations including that the gram-positive bacteria are the major producers of antibiotics and that, in general, gram-negative bacteria are resistant to them, it has been proposed that the outer cell membrane in gram-negative bacteria (diderms) has evolved as a protective mechanism against antibiotic selection pressure. Some bacteria, such as "Deinococcus", which stain gram-positive due to the presence of a thick peptidoglycan layer and also possess an outer cell membrane are suggested as intermediates in the transition between monoderm (gram-positive) and diderm

neg: Bacterial morphological plasticity run-and-tumble strategy. However, there is a study showed that the probability of random contacts between predators and prey increases with bacterial swimming, and motile bacteria can be consumed at higher rates by HNFs. In addition, bacterial surface properties affect predation as well as other factors. For example, there is an evidence shows that protists prefer gram-negative bacteria than gram-positive bacteria. Protists consume gram-positive cells at much lower rates than consuming gram-negative cells. The heterotrophic nanoflagellates actively avoid grazing on gram-positive actinobacteria as well. Grazing on gram-positive cells takes longer digestion time than on gram-negative cells. As a result of this,

neg: Gram-positive bacteria GC content, but this is lower than that of the Actinobacteria. Although bacteria are traditionally divided into two main groups, gram-positive and gram-negative, based on their Gram stain retention property, this classification system is ambiguous as it refers to three distinct aspects (staining result, envelope organization, taxonomic group), which do not necessarily coalesce for some bacterial species. The gram-positive and gram-negative staining response is also not a reliable characteristic as these two kinds of bacteria do not form phylogenetic coherent groups. However, although Gram staining response is an empirical criterion, its basis lies in the marked differences in the ultrastructure

neg: Bacteria argue that the Archaea and Eukaryotes evolved from gram-positive bacteria. The identification of bacteria in the laboratory is particularly relevant in medicine, where the correct treatment is determined by the bacterial species causing an infection. Consequently, the need to identify human pathogens was a major impetus for the development of techniques to identify bacteria. The "Gram stain", developed in 1884 by Hans Christian Gram, characterises bacteria based on the structural characteristics of their cell walls. The thick layers of peptidoglycan in the "gram-positive" cell wall stain purple, while the thin "gram-negative" cell wall appears pink. By combining morphology and Gram-staining,

neg: Broad-spectrum antibiotic to as "gram-positive," those that take up the counterstain only are "gram-negative," and those that remain unstained are referred to as "atypical." Further classification includes their requirement for oxygen (ie, aerobic or anaerobic), patterns of hemolysis, or other chemical properties. The most commonly encountered groupings of bacteria include gram-positive cocci, gram-negative bacilli, atypical bacteria, and anaerobic bacteria. Antibiotics are often grouped by their ability to act on different bacterial groups. For example, 1st-generation cephalosporins are primarily effective against gram-positive bacteria, while 4th-generation cephalosporins are generally effective against gram-negative bacteria. Empiric antibiotic therapy refers to the use of antibiotics to treat

neg: Dyadobacter of bacteria remediating soil contaminated with crude oil, and Strains of "D. fermentans" have been observed degrading 7,8-Benzoquinoline, an azarene with mutagenic properties. Dyadobacter Dyadobacter is a genus of gram negative rod-shaped bacteria belonging to the family Cytophagaceae in the phylum Bacteroidetes. Typical traits of the genus include yellow colony colour, positive flexirubin test and non-motile behaviours. They possess an anaerobic metabolism (oxidase positive), can utilise a broad range of carbon sources, and test positive for peroxide catalase activity. The type species is "Dyadobacter fermentans", which was isolated from surface sterilised maize leaves, (apparently named after its ability to ferment

neg: Gram-positive bacteria the number might be an overestimate since several of the reports are supported by single papers. Transformation among gram-positive bacteria has been studied in medically important species such as "Streptococcus pneumoniae", "Streptococcus mutans", "Staphylococcus aureus" and "Streptococcus sanguinis" and in gram-positive soil bacterium "Bacillus subtilis". The adjectives "Gram-positive" and "Gram-negative" derive from the surname of Hans Christian Gram; as eponymous adjectives, their initial letter can be either capital "G" or lower-case "g", depending on which style guide (e.g., that of the CDC), if any, governs the document being written. This is further explained at "Gram staining § Orthographic note". Gram-positive

neg: Tripotassium phosphate similar findings suggesting that gram-negative bacteria are more susceptible to the antibactericidal activity of tripotassium phosphate than gram-positive bacteria. A possible explanation for the findings is that the cell structure of gram-positive bacteria and yeasts confer them greater protection from the effect of tripotassium phosphate. Tripotassium phosphate and fatty acids (lauric myristic acids) were mixed and also used to treat poultry skin. These solutions eliminated more gram-positive bacteria than tripotassium phosphate by itself. The antibacterial activity of fatty acids is related to their ability to reduce the surface tension (surfactants) of the cell walls of mircoorganisms and make them susceptible

neg: Bacterial cell structure matrix substances in the walls of gram-positive bacteria may be polysaccharides or teichoic acids. The latter are very widespread, but have been found only in gram-positive bacteria. There are two main types of teichoic acid: ribitol teichoic acids and glycerol teichoic acids. The latter one is more widespread. These acids are polymers of ribitol phosphate and glycerol phosphate, respectively, and only located on the surface of many gram-positive bacteria. However, the exact function of teichoic acid is debated and not fully understood. A major component of the gram-positive cell wall is lipoteichoic acid. One of its purposes is providing an

neg: Gram-negative bacteria reactors to antibiotics and that gram-negative bacteria are, in general, resistant to them, it has been proposed that the outer cell membrane in gram-negative bacteria (diderms) evolved as a protective mechanism against antibiotic selection pressure. Some bacteria such as Deinococcus, which stain gram-positive due to the presence of a thick peptidoglycan layer, but also possess an outer cell membrane are suggested as intermediates in the transition between monoderm (gram-positive) and diderm (gram-negative) bacteria. The diderm bacteria can also be further differentiated between simple diderms lacking lipopolysaccharide; the archetypical diderm bacteria, in which the outer cell membrane contains lipopolysaccharide; and the

neg: Surfactin on its tendency to not produce resistant strains of bacteria. Consequently, this efficient mode of cell destruction is indiscriminate, and attacks red blood cells with deadly efficiency. Surfactin, true to its antibiotic nature, has a very significant antibacterial property, as it is capable of penetrating the cell membranes of all types of bacteria. There are two main types of bacteria and they are Gram-negative and Gram-positive. The two bacteria types differ in the composition of their membrane. The Gram-negative bacteria have an outer lipopolysaccharide membrane and a thin peptidoglycan layer followed by a phospholipids bilayer, whereas the Gram-positive bacteria lack

neg: Gram-positive bacteria and chemical composition of the bacterial cell wall, marked by the absence or presence of an outer lipid membrane. All gram-positive bacteria are bounded by a single-unit lipid membrane, and, in general, they contain a thick layer (20–80 nm) of peptidoglycan responsible for retaining the Gram stain. A number of other bacteria—that are bounded by a single membrane, but stain gram-negative due to either lack of the peptidoglycan layer, as in the Mycoplasmas, or their inability to retain the Gram stain because of their cell wall composition—also show close relationship to the Gram-positive bacteria. For the bacterial cells bounded by

neg: Periplasm peptidoglycan synthesis, electron transport, and alteration of substances toxic to the cell (xenobiotic metabolism). Importantly, the periplasm is devoid of ATP. Periplasm The periplasm is a concentrated gel-like matrix in the space between the inner cytoplasmic membrane and the bacterial outer membrane called the "periplasmic space" in gram-negative bacteria. Using cryo-electron microscopy it has been found that a much smaller periplasmic space is also present in gram-positive bacteria. The periplasm may constitute up to 40% of the total cell volume of gram-negative bacteria, but is a much smaller percentage in gram-positive bacteria. Although the bacteria are conventionally divided into two

neg: Cell wall lipid membrane containing lipopolysaccharides and lipoproteins. Most bacteria have the gram-negative cell wall and only the Firmicutes and Actinobacteria (previously known as the low G+C and high G+C gram-positive bacteria, respectively) have the alternative gram-positive arrangement. These differences in structure can produce differences in antibiotic susceptibility, for instance vancomycin can kill only gram-positive bacteria and is ineffective against gram-negative pathogens, such as "Haemophilus influenzae" or "Pseudomonas aeruginosa". Although not truly unique, the cell walls of Archaea are unusual. Whereas peptidoglycan is a standard component of all bacterial cell walls, all archaeal cell walls lack peptidoglycan, with the exception of one

neg: Gram-positive bacteria the classical sense, six gram-positive genera are typically pathogenic in humans. Two of these, "Streptococcus" and "Staphylococcus", are cocci (sphere-shaped). The remaining organisms are bacilli (rod-shaped) and can be subdivided based on their ability to form spores. The non-spore formers are "Corynebacterium" and "Listeria" (a coccobacillus), whereas "Bacillus" and "Clostridium" produce spores. The spore-forming bacteria can again be divided based on their respiration: "Bacillus" is a facultative anaerobe, while "Clostridium" is an obligate anaerobe. Also, "Rathybacter", "Leifsonia", and "Clavibacter" are three gram-positive genera that cause plant disease. gram-positive bacteria are capable of causing serious and sometimes fatal infections in newborn

neg: Imipenem Imipenem has a broad spectrum of activity against aerobic and anaerobic, Gram-positive and Gram-negative bacteria. It is particularly important for its activity against "Pseudomonas aeruginosa" and the "Enterococcus" species. It is not active against MRSA, however. Imipenem acts as an antimicrobial through inhibiting cell wall synthesis of various Gram-positive and Gram-negative bacteria. It remains very stable in the presence of β-lactamase (both penicillinase and cephalosporinase) produced by some bacteria, and is a strong inhibitor of β-lactamases from some Gram-negative bacteria that are resistant to most β-lactam antibiotics. "Acinetobacter anitratus", "Acinetobacter calcoaceticus", "Actinomyces odontolyticus", "Aeromonas hydrophila", "Bacteroides distasonis", "Bacteroides uniformis", and

neg: Gram-negative bacteria still treat them as a monophyletic taxon (though not a clade; his definition of monophyly requires a single common ancestor but does not require holophyly, the property that all descendants be encompassed by the taxon) and refer to the group as a subkingdom "Negibacteria". Bacteria are traditionally divided into the two groups: gram-positive and gram-negative, based on their gram-staining response. Gram-positive bacteria are also referred to as "monoderms" having one membrane, and gram-negative bacteria are also referred to as "diderms", having two membranes. These groups are often thought of as lineages, with gram-negative bacteria more closely related to one another

neg: Bacterial phyla Gram positive bacteria, many of which are notable secondary metabolite producers. There are only two phyla of monoderm Gram positive bacteria, the other being the "Firmicutes"; the actinobacteria generally have higher GC content so are sometimes called "high-CG Gram positive bacteria". Notable genera/species include "Streptomyces" (antibiotic production), "Propionibacterium acnes" (odorous skin commensal) and "Propionibacterium freudenreichii" (holes in Emmental) The "Aquificae" (diderm Gram negative) contains only 14 genera (including Aquifex and Hydrogenobacter). The species are hyperthermophiles and chemolithotrophs (sulphur). According to some studies, this may be one of the most deep branching phyla. The "Bacteroidetes" (diderm Gram negative) is a member

neg: Pen-Strep common antibiotic solution for the culture of mammalian cells and it does not have any adverse effects on the cells themselves. It is first introduced in 1955 in cell culture. Penicillin is a Beta-lactam antibiotic that is effective in inhibiting Gram-positive bacteria whereas streptomycin is aminoglycoside antibiotic which is effective against most Gram-negative bacteria. Penicillin is a broad spectrum antibiotic against Gram positive bacteria and is relatively inexpensive, but penicillin can cause hypersensitivity reactions and is unstable in acid and alkaline pH environments . Streptomycin is a broad spectrum antibiotic against Gram negative bacteria and is also relatively inexpensive, but

neg: Periplasm the Gram-stain. A number of other bacteria which are bounded by a single membrane but stain gram-negative due to either lack of the peptidoglycan layer (viz., mycoplasmas) or their inability to retain the Gram-stain due to their cell wall composition, also show close relationship to the gram-positive bacteria. For the bacterial (prokaryotic) cells that are bounded by a single cell membrane the term "monoderm bacteria" or "monoderm prokaryotes" has been proposed. In contrast to gram-positive bacteria, all archetypical gram-negative bacteria are bounded by a cytoplasmic membrane as well as an outer cell membrane; they contain only a thin layer of

neg: Cefazolin a reaction to occur with cefazolin and other cephalosporins in patients allergic to penicillin. Resistance to cefazolin is seen in several species of bacteria, such as Mycoplasma and Chlamydia, in which case different generations of cephalosporins may be more effective. Cefazolin does not fight against Enterococcus, anaerobic bacteria or atypical bacteria among others. As a first-generation cephalosporin antibiotic, cefazolin and other first-generation antibiotics are very active against gram-positive bacteria and some gram-negative bacteria. Their broad spectrum of activity can be attributed to their improved stability to many bacterial beta-lactamases compared to penicillins. Gram-positive aerobes: Gram-Negative Aerobes: The following are not

neg: Septic shock play a role in septic shock. Septic shock involves a widespread inflammatory response that produces a hypermetabolic effect. This is manifested by increased cellular respiration, protein catabolism, and metabolic acidosis with a compensatory respiratory alkalosis. Most cases of septic shock are caused by gram-positive bacteria, followed by endotoxin-producing gram-negative bacteria, although fungal infections are an increasingly prevalent cause of septic shock. Toxins produced by pathogens cause an immune response; in gram-negative bacteria these are endotoxins, which are bacterial membrane lipopolysaccharides (LPS). In gram-positive bacteria, these are exotoxins or enterotoxins, which may vary depending on the species of bacteria. These are

neg: Discovery and development of cephalosporins place by three mechanisms. Cephalosporins must get through the bacterial cell wall in order to reach the target PBP. In comparison, it is easier to penetrate the cell wall of gram-positive bacteria than the cell wall of gram-negative bacteria. The cell wall structure of gram-positive bacteria is made routinely up by peptidoglycan which allows the passage of cephalosporin-sized molecules. The cell wall structure of gram-negative bacteria is more complex, composed of polysaccharides, lipids and proteins, and is harder to penetrate. Particles get through the outer membrane through water-filled channels, or porins, which are trans membrane proteins. During exposure to cephalosporins

neg: Bacterial cell structure of bacterial cell walls, those of gram-positive bacteria and those of gram-negative bacteria, which are differentiated by their Gram staining characteristics. For both these types of bacteria, particles of approximately 2 nm can pass through the peptidoglycan. If the bacterial cell wall is entirely removed, it is called a protoplast while if it's partially removed, it is called a spheroplast. "β"-Lactam antibiotics such as penicillin inhibit the formation of peptidoglycan cross-links in the bacterial cell wall. The enzyme lysozyme, found in human tears, also digests the cell wall of bacteria and is the body's main defense against eye infections. Gram-positive

neg: Environmental impact of silver nanoparticles less than Ag ions (~100%), but greater than AgCl colloids (66±6%). The actual cause of these results is undetermined as growth conditions and cell properties differ between nitrifying bacteria and heterotrophic "E. coli". Within toothpaste, Ag ions have been shown to have a stronger effect on gram-negative bacteria than on gram-positive bacteria. In comparison to other nanoparticles, such as gold, silver tends to have a broader antimicrobial effect, which is another reason why it is incorporated into so many products. Ag is less effective on gram-positive bacteria due to the thick layer of peptidoglycan around them that gram-negative species lack.

neg: Bacterial cell structure antigenic function. The lipid element is to be found in the membrane where its adhesive properties assist in its anchoring to the membrane. Gram-negative cell walls are thin and unlike the gram-positive cell walls, they contain a thin peptidoglycan layer adjacent to the cytoplasmic membrane. Gram-negative bacteria are stained as pink colour. The chemical structure of the outer membrane's lipopolysaccharide is often unique to specific bacterial sub-species and is responsible for many of the antigenic properties of these strains. The plasma membrane or bacterial cytoplasmic membrane is composed of a phospholipid bilayer and thus has all of the general functions

neg: Mesophile Mesophile A mesophile is an organism that grows best in moderate temperature, neither too hot nor too cold, typically between . The term is mainly applied to microorganisms. Organisms that prefer extreme environments are known as extremophiles. Mesophiles have diverse classifications, belonging to two domains: Bacteria, Archaea, and to kingdom Fungi of domain Eucarya. Mesophiles belonging to the domain Bacteria can either be gram-positive or gram-negative. Gram-positive bacteria have a cell layer made of peptidoglycan and stains purple. Gram-negative bacteria also contains peptidoglycan, yet the layer is extremely thin and stains red or pink. Oxygen requirements for mesophiles are not

neg: Streptomyces antibioticus into two compounds: Actinomycin A and Actinomycin B. Actinomycin A was found to be highly bacteriostatic (bacteria hindering) against all bacteria it was tested with. Actinomycin B displayed little bacteriostatic activity but was shown to be highly bactericidal (bacteria killing), particularly towards gram-positive bacteria. Actinomycin is also known to display antifungal properties. The antibiotic Boromycin is also produced by "S. antibioticus". This compound was first isolated from a "S. antibioticus" strain found in an African soil sample. Boromycin is active against gram-positive bacteria, but inactive against gram-negative bacteria. Boromycin has also been shown to have antifungal and antiprotozoal properties. Certain

neg: Gram-positive bacteria a single cell membrane, the term "monoderm bacteria" or "monoderm prokaryotes" has been proposed. In contrast to gram-positive bacteria, all archetypical gram-negative bacteria are bounded by a cytoplasmic membrane and an outer cell membrane; they contain only a thin layer of peptidoglycan (2–3 nm) between these membranes. The presence of inner and outer cell membranes defines a new compartment in these cells: the periplasmic space or the periplasmic compartment. These bacteria have been designated as "diderm bacteria." The distinction between the monoderm and diderm bacteria is supported by conserved signature indels in a number of important proteins (viz. DnaK, GroEL).

neg: Gram stain Gram stain Gram stain or Gram staining, also called Gram's method, is a method of staining used to distinguish and classify bacterial species into two large groups (gram-positive and gram-negative). The name comes from the Danish bacteriologist Hans Christian Gram, who developed the technique. Gram staining differentiates bacteria by the chemical and physical properties of their cell walls by detecting peptidoglycan, which is present in the cell wall of Gram-positive bacteria. Gram-negative cells also contain peptidoglycan, but a very small layer of it that is dissolved when the alcohol is added. This is why the cell loses its initial color

neg: Tectivirus the Rz/Rz1 proteins of phage lambda). Tectiviruses have been classified into three major groups: (1) phages that infect Gram-negative bacteria (which lyse the host cell, not forming prophages) (2) those that infect Gram-positive bacteria (forming prophages) and (3) a virus that infects "Gluconobacter cerinus". The tectivirus groups have a similar genome size and organization, but they have no detectable sequence similarity at the nucleotide level. Three genera have been identified in this family: Alpatectivirus - infecting Enterobactericeae; Betatectivirus - infecting Gram positive bacteria; and Gammatectivirus. Examples Tectivirus Tectiviridae is a family of viruses with three genera. Gram-negative bacteria serve as

neg: Ubiquitin of Pup in gram-positive bacteria and were termed UBact (for Ubiquitin bacterial), although the distinction has yet not been proven to be phylogenetically supported by a separate evolutionary origin and is without experimental evidence. The finding of the Pup/UBact-proteasome system in both gram-positive and gram-negative bacteria suggests that either the Pup/UBact-proteasome system evolved in bacteria prior to the split into gram positive and negative clades over 3000 million years ago[14] or, that these systems were acquired by different bacterial lineages through horizontal gene transfer(s) from a third, yet unknown, organism. In support of the second possibility, two "UBact" loci were

neg: Archaea organism's genes, are common between Archaea and Bacteria, while most genes involved in genome expression are common between Archaea and Eukarya. Within prokaryotes, archaeal cell structure is most similar to that of gram-positive bacteria, largely because both have a single lipid bilayer and usually contain a thick sacculus (exoskeleton) of varying chemical composition. In some phylogenetic trees based upon different gene/protein sequences of prokaryotic homologs, the archaeal homologs are more closely related to those of gram-positive bacteria. Archaea and gram-positive bacteria also share conserved indels in a number of important proteins, such as Hsp70 and glutamine synthetase I;, but the

neg: Gram-negative bacteria than to gram-positive bacteria. While this is often true, the classification system breaks down in some cases. A given bacteria's staining result, bacterial membrane organization, and lineage groupings do not always match up. Thus, gram-staining cannot be reliably used to assess familial relationships of bacteria. However, staining often gives reliable information about the composition of the cell membrane, distinguishing between the presence or absence of an outer lipid membrane. Of these two structurally distinct groups of prokaryotic organisms, monoderm prokaryotes are indicated to be ancestral. Based upon a number of different observations including that the gram-positive bacteria are the major

neg: FLS2 in mind, it is important that all gram positive and gram negative bacteria share flagellin. With plants being stationary, a specific molecular pattern of flagellin can be recognized by plants to determine phytopathogenic bacteria in plant defense. As discovered by the ectopic expression of "FLS2" study, "FLS2" is directed related to flagellin perception, so by discovery and by natural way of the plant, "FLS2" is the gene responsible for perception of flagellin which signals a plant defense response. Things are not all settled here because, as mentioned earlier, gram positive and gram negative bacteria share flagellin which means that plants

neg: Azithromycin is about 4 for a course of treatment . Azithromycin is used to treat many different infections, including: Azithromycin has relatively broad but shallow antibacterial activity. It inhibits some Gram-positive bacteria, some Gram-negative bacteria, and many atypical bacteria. A strain of gonorrhea reported to be highly resistant to azithromycin was found in the population in 2015. "Neisseria gonorrhoeae" is normally susceptible to azithromycin, but the drug is not widely used as monotherapy due to a low barrier to resistance development. Extensive use of azithromycin has resulted in growing Streptococcus pneumoniae resistance. Aerobic and facultative Gram-positive microorganisms Aerobic and facultative Gram-negative

neg: Cell wall kill bacteria by preventing the cross-linking of peptidoglycan and this causes the cell wall to weaken and lyse. The lysozyme enzyme can also damage bacterial cell walls. There are broadly speaking two different types of cell wall in bacteria, called gram-positive and gram-negative. The names originate from the reaction of cells to the Gram stain, a test long-employed for the classification of bacterial species. Gram-positive bacteria possess a thick cell wall containing many layers of peptidoglycan and teichoic acids. In contrast, gram-negative bacteria have a relatively thin cell wall consisting of a few layers of peptidoglycan surrounded by a second

neg: Bacteria most bacteria can be classified as belonging to one of four groups (gram-positive cocci, gram-positive bacilli, gram-negative cocci and gram-negative bacilli). Some organisms are best identified by stains other than the Gram stain, particularly mycobacteria or "Nocardia", which show acid-fastness on Ziehl–Neelsen or similar stains. Other organisms may need to be identified by their growth in special media, or by other techniques, such as serology. Culture techniques are designed to promote the growth and identify particular bacteria, while restricting the growth of the other bacteria in the sample. Often these techniques are designed for specific specimens; for example, a sputum

neg: Mycorrhiza helper bacteria Mycorrhiza helper bacteria Mycorrhiza helper bacteria (MHB) are a group of organisms that form symbiotic associations with both ectomycorrhiza and arbuscular mycorrhiza. MHBs are diverse and belong to different bacterial phyla including both gram-negative and gram-positive bacteria. Some of the most common types are "Pseudomonas" and "Streptomyces". MHBs have specific interactions with fungi, but not with the plants. MHB enhance mycorrhizal function, increase mycorrhizal growth, provide nutrients to the fungus and plant, improve soil conductance, select to aid pathogens, and help promote defense mechanisms. MHBs consist of a diverse group of organisms, often gram-negative and gram-positive bacteria. Most of the

neg: Archaea phylogeny of these genes was interpreted to reveal interdomain gene transfer, and might not reflect the organismal relationship(s). It has been proposed that the archaea evolved from gram-positive bacteria in response to antibiotic selection pressure. This is suggested by the observation that archaea are resistant to a wide variety of antibiotics that are primarily produced by gram-positive bacteria, and that these antibiotics primarily act on the genes that distinguish archaea from bacteria. The proposal is that the selective pressure towards resistance generated by the gram-positive antibiotics was eventually sufficient to cause extensive changes in many of the antibiotics' target genes,

neg: Ampicillin used to treat gonorrhea, but there are now too many strains resistant to penicillins. Ampicillin is used to treat infections by many Gram-positive and Gram-negative bacteria. It was the first "broad spectrum" penicillin with activity against Gram-positive bacteria, including "Streptococcus pneumoniae", "Streptococcus pyogenes", some isolates of "Staphylococcus aureus" (but not penicillin-resistant or methicillin-resistant strains), "Trueperella", and some "Enterococcus". It is one of the few antibiotics that works against multidrug resistant "Enterococcus faecalis" and "E. faecium". Activity against Gram-negative bacteria includes "Neisseria meningitidis", some "Haemophilus influenzae", and some of the Enterobacteriaceae (though most Enterobacteriaceae and "Pseudomonas" are resistant). Its spectrum of

neg: Arsenate-reducing bacteria "ars" operons for arsenic resistance in most bacteria and some archaeal genomes. It is a monomeric protein of about 135 amino acids containing 3 essential cysteine residues involved in a cascade sequence of enzyme activity. There are no cofactors in the ArsC enzyme. The first recognized cytoplasmic arsenate reductase was found on a Gram-positive "Staphylococcus" plasmid. The thioredoxin-coupled clade of arsenate reductases is found widely among plasmids and genomes of Gram-positive bacteria and also in some Gram-negative bacteria. The "Pseudomonas aeruginosa" genome has separate genes for glutaredoxin- and thioredoxin-coupled ArsC reductases. In contrast, those for cyanobacteria seem to be an

neg: Gram-negative bacteria cephalosporins, beta-lactam-betalactamase combinations (e.g. pipercillin-tazobactam), Folate antagonists, quinolones, and carbapenems. Many of these antibiotics also cover gram positive organisms. The drugs that specifically target gram negative organisms include aminoglycosides, monobactams (aztreonam) and Ciprofloxacin. Gram-negative bacteria display : Along with cell shape, gram-staining is a rapid diagnostic tool and once was used to group species at the subdivision of Bacteria. Historically, the kingdom Monera was divided into four divisions based on gram-staining: Firmacutes (+), Gracillicutes (−), Mollicutes (0) and Mendocutes (var.). Since 1987, the monophyly of the gram-negative bacteria has been disproven with molecular studies. However some authors, such as Cavalier-Smith

neg: Discovery and development of cephalosporins space between the inner and outer membrane so they can't easily escape into the extracellular space, and don't have to be biosynthesized in high quantities. This section will review the drug development from one generation to the next with emphasis on the structural differences between the generations. The generation classification system relies on dividing the cephalosporins by their chemical properties and their relative activity against gram-negative versus gram-positive bacteria. [14]. From the first generation cephalosporins to the third generation there is a development from being more effective against gram-positive bacteria to being more effective against gram-negative bacteria and less effective

neg: Sepsis lightheadedness and is part of the criteria for septic shock. Infections leading to sepsis are usually bacterial, but may be fungal or viral. Gram-positive bacteria was the predominant cause of sepsis before the introduction of antibiotics in the 1950s. After the introduction of antibiotics, gram-negative bacteria became the predominant cause of sepsis from the 1960s to the 1980s. After the 1980s, gram-positive bacteria, most commonly staphylococci, are thought to cause more than 50% of cases of sepsis. Other commonly implicated bacteria include "Streptococcus pyogenes", "Escherichia coli", "Pseudomonas aeruginosa", and "Klebsiella" species. Fungal sepsis accounts for approximately 5% of severe sepsis

neg: Dyadobacter Dyadobacter Dyadobacter is a genus of gram negative rod-shaped bacteria belonging to the family Cytophagaceae in the phylum Bacteroidetes. Typical traits of the genus include yellow colony colour, positive flexirubin test and non-motile behaviours. They possess an anaerobic metabolism (oxidase positive), can utilise a broad range of carbon sources, and test positive for peroxide catalase activity. The type species is "Dyadobacter fermentans", which was isolated from surface sterilised maize leaves, (apparently named after its ability to ferment glucose and fructose). Species of "Dyadobacter" have been isolated from a diverse range of environments worldwide, including glacial ice, seawater and factories, however

neg: Oriental hornet hornets can also transmit some serious diseases. They transmit infectious microbes to fruits and other human foods. They may also transmit diseases by attacking infected honey bee hives and then transmitting disease to healthy nests. The hornets may also have harmful effects on plants and crops by transmitting fungi and bacteria from infected plants to healthy plants. The venom of "Vespa orientalis" was tested on gram-positive bacteria, "Staphylococcus aureus" and "Bacillus subtilis", and gram-negative bacteria, "Escherichia coli" and "Klebsiella pneumonia". Venom extract was shown to be effective in inhibiting the growth of gram-positive bacteria. The venom is therefore regarded as

neg: Bombus ignitus "B. ignitus," has been identified as a serine protease inhibitor. BiVSPI exhibits antimicrobial functions, and has been found to inhibit the growth of Gram-positive bacteria and fungi. The cDNA of four antibacterial peptide genes - apidaecin, hymenoptaecin, abaecin, and defensin - were isolated and cloned from "B. ignitus." Synthesized abaecin has been shown to inhibit the growth of Gram- negative bacteria, but had little inhibitory effect towards the growth of Gram-positive bacteria. Bombus ignitus Bombus ignitus is a species of bumblebee in the family Apidae. It is mainly distributed in Eastern Asia, commonly found in China, Japan, and Korea. It

neg: Beta-defensin 2 that HBD-2 is a dynamic component of the local epithelial defense system of the skin and respiratory tract having a role to protect surfaces from infection, and providing a possible reason why skin and lung infections with Gram-negative bacteria are rather rare. Although this protein doesn’t have any antibacterial activity against Gram-positive bacteria, there is a study showing that there is a synergy between hBD-2 and other proteins. One example of this synergistic effect is with epiP, a protein segregated by some strains of "S. epidermidis". hBD2, holding hands with epiP, is capable of killing "S. aureus", a Gram-positive bacteria

neg: Eosin methylene blue methylene blue (dye), and agar. There are also EMB agars that do not contain lactose. Eosin methylene blue Eosin methylene blue (EMB, also known as "Levine's formulation") is a selective stain for gram-negative bacteria. EMB contains dyes that are toxic to gram-positive bacteria. EMB is the selective and differential medium for coliforms. It is a blend of two stains, eosin and methylene blue in the ratio of 6:1. A common application of this stain is in the preparation of EMB agar, a differential microbiological medium, which slightly inhibits the growth of Gram-positive bacteria and provides a color indicator distinguishing between

neg: Eosin methylene blue Eosin methylene blue Eosin methylene blue (EMB, also known as "Levine's formulation") is a selective stain for gram-negative bacteria. EMB contains dyes that are toxic to gram-positive bacteria. EMB is the selective and differential medium for coliforms. It is a blend of two stains, eosin and methylene blue in the ratio of 6:1. A common application of this stain is in the preparation of EMB agar, a differential microbiological medium, which slightly inhibits the growth of Gram-positive bacteria and provides a color indicator distinguishing between organisms that ferment lactose (e.g., "E. coli") and those that do not (e.g., "Salmonella", "Shigella").

neg: Tigecycline bacterial infections, including complicated skin and structure infections, complicated intra-abdominal infections and community-acquired bacterial pneumonia. Tigecycline is a glycylcycline antibiotic that covers MRSA and Gram-negative organisms: Tigecycline is given intravenously and has activity against a variety of Gram-positive and Gram-negative bacterial pathogens, many of which are resistant to existing antibiotics. Tigecycline successfully completed phase III trials in which it was at least equal to intravenous vancomycin and aztreonam to treat complicated skin and skin structure infections, and to intravenous imipenem and cilastatian to treat complicated intra-abdominal infections. Tigecycline is active against many Gram-positive bacteria, Gram-negative bacteria and anaerobes – including

neg: Quorum sensing diffuse away. At high cell density, the local concentration of signaling molecules may exceed its threshold level, and trigger changes in gene expressions. Gram-positive bacteria use autoinducing peptide (AIP) as their autoinducers. When gram-positive bacteria detect high concentration of AIP in the environment, AIP bind to a receptor to activate kinase. The kinase phosphorylates a transcription factor, which regulated gene transcription. This is called a two-component system. Another possible mechanism is that AIP is transported into the cytosol, and binds directly to a transcription factor to initiate or inhibit transcription. Gram-negative bacteria produce N-acyl homoserine lactones (AHL) as their signaling

neg: Gram-positive bacteria infants. Transformation is one of three processes for horizontal gene transfer, in which exogenous genetic material passes from a donor bacterium to a recipient bacterium, the other two processes being conjugation (transfer of genetic material between two bacterial cells in direct contact) and transduction (injection of donor bacterial DNA by a bacteriophage virus into a recipient host bacterium). In transformation, the genetic material passes through the intervening medium, and uptake is completely dependent on the recipient bacterium. As of 2014 about 80 species of bacteria were known to be capable of transformation, about evenly divided between gram-positive and gram-negative bacteria;

neg: Autoinducer their extracellular environments. Most Gram-positive bacteria use a two-component signaling mechanism in quorum sensing. Secreted peptide autoinducers accumulate as a function of cell density. Once a quorum level of autoinducer is achieved, its interaction with a sensor kinase at the cell membrane initiates a series of phosphorylation events that culminate in the phosphorylation of a regulator protein intracellularly. This regulator protein subsequently functions as a transcription factor and alters gene expression. Similar to Gram-negative bacteria, the autoinduction and quorum sensing system in Gram-positive bacteria is conserved, but again, individual species have tailored specific aspects for surviving and communicating in unique

neg: ATP-binding cassette transporter two ATP molecules can be cooperative, that is, ATP must bind to the two active site pockets before the NBDs can dimerize and form the closed, catalytically active conformation. Most ABC transporters that mediate the uptake of nutrients and other molecules in bacteria rely on a high-affinity solute binding protein (BP). BPs are soluble proteins located in the periplasmic space between the inner and outer membranes of gram-negative bacteria. Gram-positive microorganisms lack a periplasm such that their binding protein is often a lipoprotein bound to the external face of the cell membrane. Some gram-positive bacteria have BPs fused to the

neg: Siderophore in microbe siderophore production and uptake are derepressed, leading to manufacture of siderophores and the appropriate uptake proteins. In bacteria, Fe-dependent repressors bind to DNA upstream to genes involved in siderophore production at high intracellular iron concentrations. At low concentrations, Fe dissociates from the repressor, which in turn dissociates from the DNA, leading to transcription of the genes. In gram-negative and AT-rich gram-positive bacteria, this is usually regulated by the "Fur" (ferric uptake regulator) repressor, whilst in GC-rich gram-positive bacteria (e.g. Actinobacteria) it is "DtxR" (diphtheria toxin repressor), so-called as the production of the dangerous diphtheria toxin by "Corynebacterium diphtheriae"

neg: Hospital-acquired infection and germicides. Among the categories of bacteria most known to infect patients are the category MRSA (resistant strain of "S. aureus"), member of gram-positive bacteria and "Acinetobacter" ("A. baumannii"), which is gram-negative. While antibiotic drugs to treat diseases caused by gram-positive MRSA are available, few effective drugs are available for "Acinetobacter". "Acinetobacter" bacteria are evolving and becoming immune to existing antibiotics, so in many cases, polymyxin-type antibacterials need to be used. "In many respects it’s far worse than MRSA," said a specialist at Case Western Reserve University. Another growing disease, especially prevalent in New York City hospitals, is the drug-resistant,

neg: Cell membrane groups, Archaea and Bacteria, with bacteria dividing further into gram-positive and gram-negative. Gram-negative bacteria have both a plasma membrane and an outer membrane separated by periplasm, however, other prokaryotes have only a plasma membrane. These two membranes differ in many aspects. The outer membrane of the gram-negative bacteria differ from other prokaryotes due to phospholipids forming the exterior of the bilayer, and lipoproteins and phospholipids forming the interior. The outer membrane typically has a porous quality due to its presence of membrane proteins, such as gram-negative porins, which are pore-forming proteins. The inner, plasma membrane is also generally symmetric whereas

neg: Bacterial secretion system Bacterial secretion system Bacterial secretion systems are protein complexes present on the cell membranes of bacteria for secretion of substances. Specifically, they are the cellular devices used by pathogenic bacteria to secrete their virulence factors (mainly of proteins) to invade the host cells. They can be classified into different types based on their specific structure, composition and activity. These major differences can be distinguished between Gram-negative and Gram-negative bacteria. But the classification is by no means clear and complete. There are at least eight types specific to Gram-negative bacteria, four to Gram-positive bacteria, while two are common to both. Generally,

neg: Enrofloxacin a significant post-antibiotic effect for both Gram-negative and Gram-positive bacteria and is active in both stationary and growth phases of bacterial replication. Enrofloxacin is partially deethylated by CYP450 into the active metabolite ciprofloxacin, which is also a fluoroquinolone antibiotic. Enrofloxacin is a synthetic antibacterial agent from the class of the fluoroquinolone carboxylic acid derivatives. It has antibacterial activity against a broad spectrum of Gram-negative and Gram-positive bacteria. It is effective against: Variable activity against: Ineffective against: The following data represent minimum inhibitory concentration ranges for a few medically significant bacterial pathogens: Usage in poultry. Enrofloxacin was banned for poultry use

neg: Lantibiotics the transport of the molecule out of the synthesising cell. They are synthesized by ribosomes, which distinguishes them from most natural antibiotics. There are four known enzymes (lanthipeptide synthetases) responsible for producing lanthionine rings. Lantibiotics show substantial specificity for some components (e.g., lipid II) of bacterial cell membranes especially of Gram-positive bacteria. Type A lantibiotics kill rapidly by pore formation, type B lantibiotics inhibit peptidoglycan biosynthesis. They are active in very low concentrations. Lantibiotics are produced by Gram-positive bacteria and show strong antimicrobial action toward a wide range of other Gram-positive bacteria. As such, they have become attractive candidates for

neg: Acetobacterium Acetobacterium Acetobacterium is a genus of anaerobic, Gram-positive bacteria that belong to the Eubacteriaceae family. The type species of this genus is "Acetobacterium woodii". The name, "Acetobacterium", has originated because they are acetogens, predominantly making acetic acid as a byproduct of anaerobic metabolism. Most of the species reported in this genus are homoacetogens, i.e. solely producing acetic acid as their metabolic byproduct. They should not be confused with acetic acid bacteria which are aerobic, Gram-negative Alphaproteobacteria. Other acetogens use the Wood–Ljungdahl pathway to reduce CO or CO and produce acetate, but what distinguishes "A.woodii" and other "Acetobacterium" from other acetogens

neg: Cefaclor fluid poorly unless the meninges are inflamed; cefotaxime is a more suitable cephalosporin than cefaclor for infections of the central nervous system, e.g. meningitis. Cefaclor is active against many bacteria, including both Gram-negative and Gram-positive organisms. Cefaclor is frequently used against bacteria responsible for causing skin infections, otitis media, urinary tract infections, and others. Cefaclor has been shown to be active against most strains of the following microorganisms, both in vitro and in clinical infections: Gram positive aerobes - Staphylococci (including coagulase-positive, coagulase-negative, and penicillinase-producing strains), Streptococcus pneumoniae, and Streptococcus pyogenes (group A ß-hemolytic streptococci). The following represents MIC susceptibility

neg: Corynebacterium twin-arginine translocation pathway. Unlike gram-negative bacteria, the gram-positive "Corynebacterium" species lack lipopolysaccharides that function as antigenic endotoxins in humans. Most species of corynebacteria are not lipophilic. The nonlipophilic bacteria may be classified as fermentative and nonfermentative: Corynebacterium Corynebacterium () is a genus of bacteria that are Gram-positive and aerobic. They are bacilli (rod-shaped), and in some phases of life they are, more particularly, club-shaped, which inspired the genus name ("coryneform" means "club-shaped"). They are widely distributed in nature in the microbiota of animals (including the human microbiota) and are mostly innocuous, most commonly existing in commensal relationships with their hosts.

neg: Clostridioides difficile (bacteria) Clostridioides difficile (bacteria) Clostridioides difficile (syn. "Clostridium difficile"), also known as C. difficile, C. diff (), or sometimes CDF/cdf, is a species of Gram-positive spore-forming bacterium. "Clostridioides" are anaerobic, motile bacteria, ubiquitous in nature, and especially prevalent in soil. Its vegetative cells are rod shaped, pleomorphic, and occur in pairs or short chains. Under the microscope, they appear as long, irregular (often drumstick- or spindle-shaped) cells with a bulge at their terminal ends (forms subterminal spores). Under Gram staining, "C. difficile" cells are Gram-positive and show optimum growth on blood agar at human body temperatures in the absence of oxygen.

neg: Cefotiam Cefotiam Cefotiam is a parenteral second-generation cephalosporin antibiotic. It has broad-spectrum activity against Gram-positive and Gram-negative bacteria. As a beta-lactam, its bactericidal activity results from the inhibition of cell wall synthesis via affinity for penicillin-binding proteins. Cefotiam was launched as Pansporin in February 1981 by Takeda Pharmaceutical of Japan and has been available as a generic since February 1993. Cefotiam inhibits final cross-linking stage of peptidoglycan production, thus inhibiting bacterial cell wall synthesis. It has similar or less activity against Gram-positive staphylococci and streptococci, but is resistant to some beta-lactamases produced by Gram-negative bacteria. It is more active against many

neg: Gram-negative bacteria other two being conjugation (transfer of genetic material between two bacterial cells in direct contact) and transduction (injection of foreign DNA by a bacteriophage virus into the host bacterium). In transformation, the genetic material passes through the intervening medium, and uptake is completely dependent on the recipient bacterium. As of 2014 about 80 species of bacteria were known to be capable of transformation, about evenly divided between Gram-positive and Gram-negative bacteria; the number might be an overestimate since several of the reports are supported by single papers. Transformation has been studied in medically important Gram-negative bacteria species such as "Helicobacter

neg: Alpha acid varieties depending on growing conditions, drying methods, age of the hop, and other factors. For example, this list shows the typical range of alpha acids found in some common varieties (percentages are based on total dried weight). Iso-α-acids have a bacteriostatic effect on many common Gram-positive bacteria found in beer. While the iso-α-acids are very effective at preventing serious contamination from Gram-positive bacteria such as the lactic acid bacteria, there are some strains that are quite resistant to the effects of the iso-α-acids. The iso-α-acids have no effect on Gram-negative bacteria, and therefore the brewer must rely on maintaining proper

neg: Altered Schaedler flora and is closely related to "Roseburia ceciola". ASF 356, ASF 492, and ASF 502 are all part of the low G+C, Gram-positive bacteria of the Clostridium cluster XIV. ASF 500 is a deeper branch into the low G+C, Gram-positive bacteria of Firmicutes, Bacillus-Clostridium group, but not much can be found in the GenBank database on this branch of Clostridium cluster Only mice have been colonized with ASF in experiments, since ASF bacteria originate from mice intestinal microbiome. Germfree mice are colonized by ASF through one of two methods. Pure culture of each living ASF bacteria can be grown in anaerobic

neg: Vancomycin the bacterial cell wall, and it prevents the backbone polymers that do manage to form from cross-linking with each other. Vancomycin is one of the few antibiotics used in plant tissue culture to eliminate Gram-positive bacterial infection. It has relatively low toxicity to plants. A few Gram-positive bacteria are intrinsically resistant to vancomycin: "Leuconostoc" and "Pediococcus" species, but these organisms rarely cause diseases in humans. Most "Lactobacillus" species are also intrinsically resistant to vancomycin, with the exception of "L. acidophilus" and "L. delbruekii", which are sensitive. Other Gram-positive bacteria with intrinsic resistance to vancomycin include "Erysipelothrix rhusiopathiae", "Weissella confusa", and

neg: Omadacycline Omadacycline Omadacycline (formerly known as PTK-0796) is a broad spectrum antibiotic belonging to the aminomethylcycline subclass of tetracycline antibiotics. In the United States, it was approved in October 2018 for the treatment of community-acquired bacterial pneumonia and acute skin and skin structure infections. "In vitro" studies have shown that omadacycline has activity against a broad range of Gram-positive and select Gram-negative pathogens. Omadacycline has potent "in vitro" activity against Gram-positive aerobic bacteria including methicillin-resistant Staphylococcus aureus (MRSA), pencillin-resistant and multi-drug resistant "Streptococcus pneumoniae", and vancomycin-resistant "Enterococcus". Omadacycline also has antimicrobial activity against common Gram-negative aerobes, some anaerobes, and atypical bacteria

neg: Trimeric autotransporter adhesin surface components recognizing adhesive matrix molecules (MSCRAMMs). In other words, they are a complex that aids adhesion to the ECM. Secretion is one method of transferring substances across the bacterial outer membrane. Gram-negative bacteria have very different cell wall structures in comparison to Gram-positive bactera. Gram-negative bacteria have three layers: The innermost layer is named the inner membrane; the middle layer, named the periplasmic space, is a space containing a thin layer of peptidoglycan; and the third layer is named the outer membrane, which contains lipopolysaccharides. In Gram-negative bacteria, the secretary pathway is very different from that of eukaryotes or

neg: Bacterial pneumonia Bacterial pneumonia Bacterial pneumonia is a type of pneumonia caused by bacterial infection. "Streptococcus pneumoniae" () is the most common bacterial cause of pneumonia in all age groups except newborn infants. "Streptococcus pneumoniae" is a Gram-positive bacterium that often lives in the throat of people who do not have pneumonia. Other important Gram-positive causes of pneumonia are "Staphylococcus aureus" () and "Bacillus anthracis". Gram-negative bacteria are seen less frequently: "Haemophilus influenzae" (), "Klebsiella pneumoniae" (), "Escherichia coli" (), "Pseudomonas aeruginosa" (), "Bordetella pertussis", and "Moraxella catarrhalis" are the most common. These bacteria often live in the gut and enter the

neg: Bacteremia children that appeared otherwise well. Bacteria can enter the bloodstream in a number of different ways. However, for each major classification of bacteria (gram negative, gram positive, or anaerobic) there are characteristic sources or routes of entry into the bloodstream that lead to bacteremia. Causes of bacteremia can additionally be divided into healthcare-associated (acquired during the process of receiving care in a healthcare facility) or community-acquired (acquired outside of a health facility, often prior to hospitalization). Gram positive bacteria are an increasingly important cause of bacteremia. Staphyloccocus, streptococcus, and enterococcus species are the most important and most common species of

neg: Cefodizime of cytokines in the stimulated cells. A 1992 study conducted in vitro susceptibility studies for cefodizime and found that gram negative bacteria with consistent susceptibility include: "Enterobacteriaceae" including "E. coli", "Klebsiella pneumonia", "Morganella morganii", "Proteus mirabilis", "P. vulgaris", "Shigella sonnei", "Yersinia enterocolitica", "Salmonella", "Haemophilus influenzae", "Moraxella catarrhalis", "Neisseria gonorrhoeae", and "Neisseria meningitidis". "In vitro" susceptible gram positive bacteria include: methicillin-sensitive "Staphylococcus aureus", and "Streptococcus agalactiae", "S. pneumoniae" and "S. pyogenes". Cefodizime was shown to be ineffective "in vitro" against "Enterobacter spp.", "Pseudomonas aeruginosa", and "Xanthomonas maltophilia". Gram positive bacteria it was inactive against include "Staphylococcus epidermidis" and "methicillin-resistant "Streptococcus aureus".