Different bacteria produce an important class of enzymes called beta-lactamases, which may be mediated by genes on plasmids or chromosomes. These enzymes confer resistance to a number of penicillin antibiotics…
…also enter other metabolic pathways for the synthesis of other cellular protoplasmic requirements. However, before their assimilation by bacteria, they need to be degraded. The degradation of lipids such as…
…for preservation and storage of bacterial cultures · Crystal violet blood agar Selective media for Streptococcus pyogenes · Cysteine Lactose Electrolyte De?cient Media (CLED Media) Most commonly used media for…
…this medium to 3.5 +/- 0.1, inhibiting bacterial growth. Chloramphenicol acts as a selective agent to inhibit bacterial overgrowth of competing microorganisms from mixed specimens, while permitting the selective isolation of…
…agent and inhibits most bacteria by acting as a detergent. When in contact with bacteria, causes the release of nitrogen and phosphorous from the bacterial cell other than Pseudomonas aeruginosa. Glycerol…
…and sodium citrate, as well as the alkalinity of the medium, considerably inhibit the growth of Enterobacteria. Ox bile and sodium cholate slow the growth of enterococci and inhibit the development of…
…of medium. Selenite is reduced by bacterial growth and alkali is produced. An increase in pH lessens the toxicity of the selenite and results in overgrowth of other bacteria. The acid produced…
…can be cultured in cell monolayers. Gram Staining is not preferred but if done may appear as gram negative bacteria. Gimenez stain is preferred. The organism is highly virulent and…
…bacteria suspended in a solution over a plate. The plate needs to be dry and at room temperature so that the agar can absorb the bacteria more readily. A successful…
Esculin is a glycosidic coumarin derivative (6-beta-glucoside-7-hydroxy-coumarin). The two moieties of the molecule (glucose and 7-hydroxycoumarin) are linked together by an ester bond through oxygen. Many bacteria can hydrolyze esculin, but…
The ability of bacteria to ferment lactose depends on two enzymes, permease and beta-galactosidase. Permease allows lactose to enter the bacterial cell wall, where it is then broken down into…
…gas produced by metabolism. The carbohydrate fermentation patterns shown by different organisms are useful in differentiating among bacterial groups or species. Media Phenol Red Broth is a general-purpose differential test…
The ability of the bacteria to grow in the presence of variable amount of Sodium Chloride (NaCl) has been used to characterize several bacteria. It takes into account the organism’s…
…crystals are seen in patients with urinary tract infections caused by urea-splitting bacteria, such as Proteus mirabilis, and are frequently found in the urine of patients with infected calculi (struvite stones). In addition…
…of PCR technology to provide early, time critical information based on detection and recognition of bacterial or fungal pathogen DNA. By this new modern method, the results are chosen in…
…used as slide and tube techniques. Principle of Widal Test Bacterial suspension which carry antigen will agglutinate on exposure to antibodies to Salmonella organisms. Patients’ suffering from enteric fever would possess…
…sole source of nitrogen. Bacteria that can grow on this medium produce an enzyme, citrate-permease, capable of converting citrate to pyruvate. Pyruvate can then enter the organism’s metabolic cycle for the production of energy. Growth…
Starch Casein Agar (SCA) is used for the detection of saccharolytic marine bacteria and mostly actinomycetes. Actinomycetes are a fungi-like bacteria forming long filaments that stretch through the soil. They…
…Shape and Arrangement of Bacterial Cells All About Benedict’s Test Best Microbiology Books Differences Between Exotoxins and Endotoxins About the Author – Sagar Aryal My name is Sagar Aryal and…
…contact me am voluntere to discuss specially in bacterial identification and isolation Anna Thanks You make this articule very good and nice.Normally i know this but not all streptococcus viridans…
…is the solidifying agent. Organisms capable of utilizing ammonium dihydrogen phosphate and citrate will grow unrestricted on this medium. If citrate can be used, the microbe will accumulate alkaline/basic byproducts. Bacteria that…
…into sterile Petri plates. Result Interpretation on Salmonella Shigella Agar Salmonella will not ferment lactose, but produce hydrogen sulfide (H2S) gas. The resulting bacterial colonies will appear colorless with black…
…a group of certain bacteria while inhibiting the growth of others. It is a selective medium prepared according to the recommendations of Chapman for the isolation of presumptive pathogenic staphylococci….
Amino acids are metabolized variably by gram negative aerobic and facultatively anaerobic bacteria as well as gram positive cocci. These amino acids are decarboxylated, hydrolysed or deaminated depending on the…
…a zone of proteolysis, which is demonstrated by a clear area surrounding the bacterial growth. This loss of opacity is the result of a hydrolytic reaction yielding soluble, non-colloidal amino…
Cetrimide is a quaternary ammonium salt, which acts as a selective agent and inhibits most bacteria by acting as a cationic detergent (Cetyltrimethylammonium bromide). Cetrimide when added into a culture…
Deoxyribonucleic acid (DNA) is a large polymer of nucleotides that is way too large to enter the cell membrane. In order to utilize external DNA, bacteria cells secrete exoenzymes (DNases)…
The ability of bacteria to form organic compounds by metabolizing certain carbohydrates and related compounds is a widely used method for the identification of microorganisms. Different fermentation media are used…
…phospholipase C, which is an enzyme that splits the phospholipid lecithin. Such lecithinase activity is used to characterize several gram positive and gram negative bacteria. Objectives To determine the ability…
…and repackaging of DNA during DNA replication and the bacterial cell cycle. Novobiocin binds to DNA gyrase, and blocks adenosine triphosphatase (ATPase) activity. Susceptibility to novobiocin is determined by placing…