Introduction to Human Papiloma VIrus
Human papillomavirus (HPV) is a virus that infects the skin, genital area and lining of the cervix. There are about 100 different types of papilloma viruses (Some types of papillomaviruses…
Infections caused by anaerobes and features of anaerobic infections
Infections caused by anaerobic bacteria occur in all parts of body. These infected tissues usually contain a mixture of several kinds of anaerobes and frequently also contain aerobic and facultative…
Anaerobes: Why can’t anaerobic organism survive in presence of oxygen?
Anaerobes or anaerobic organisms are those that cannot grow in presence of oxygen. Oxygen is toxic for them so they must rely on other substances as terminal electron acceptor. Their…
Urea hydrolysis/ Urease test (Christensen’s method)
Urea hydrolysis/Urease test is used to detect the ability of an organism to produce urease that hydrolyses urea contained in the medium. Hydrolysis of urea produces ammonia and carbon dioxide The…
Triple Sugar Iron Agar test (TSI test): Principle, Procedure and Interpretation
Principle: Triple sugar iron agar test is used to determine whether gram negative bacilli utilise glucose and lactose or sucrose fermentatively and produce hydrogen sulfide (H2S). It contains 10 parts…
Citrate utilisation test: Principle, Procedure and Expected results
Principle Citrate utilisation test is used to detect the ability of an organism to utilize sodium citratre as a sole source of carbon and ammonium salt as a sole source…
Coagulase test: Principle, Procedure and Interpretation
Coagulase test is done to distinguish Staphylococcus aureus from other Coagulase negative Staphylococci (CONS) like Staphylococcus epidermidis, Staphylococcus saprophyticus etc. Staphylococcus aureus produces two types of coagulase, free coagulase and bound…
Catalase test : a test to differentiate Staphylococcus and Streptococcus
Principle: Catalase test is done to check for the presence of enzyme catalase in bacteria that hydrolyzes hydrogen peroxide (H2O2) into water (H2O) and oxygen (O2). If the bacteria possess catalase…
Bacteriological culture media / Types of culture media
Bacteria have to be grown for their identification and investigating other properties like antimicrobial susceptibility, test for enzyme production or test for virulent genes etc. By the use of appropriate…
Ziehl Neelsen Staining or AFB Staining Procedure
Smear preparation for AFB: Take a grease free scratch free glass slide to prepare the smear. (A new glass slide should be used for smear preparation, if greasy; you can…