Antibiotics as chemotherapeutic agents (characteristics and qualities)
Antibiotics are a special kind of chemotherapeutic agent usually obtained from living organism. The word ‘antibiotic’ has come to refer to a metabolic product of […]
Bacteriology
Bacterial spores and their types
Certain species of bacteria produce spores, which are metabolically dormant structure and might be present either within the cell (endospores) or external to the cell […]
Structure and arrangement of flagella in bacterial cell and types of flagellar motility
Bacterial flagella are hairlike, helical appendages that protrude through the cell wall. They are responsible for motility in bacteria and are much thinner than the […]
Oxidase test by Kovac’s method (Principle, Procedure, Result Interpretation and Precautions)
Principle: This test is performed to determine or identify the presence of an enzyme cytochrome oxidase (of the electron transport chain) in bacterial cells. The […]
Catalase test (Principle, Procedure, Result interpretation and precautions)
Principle The enzyme catalase, which is produced by many aerobic and facultative anaerobic microorganisms, neutralizes toxic forms of oxygen metabolites like hydrogen peroxide (H2O2) and […]
Helicobacter pylori (General properties, pathogenesis, lab diagnosis and treatment)
General properties: Man appears to be the sole reservoir of H.pylori and it colonizes the gastric mucosa of almost one in four of the adult […]
Growth of bacteria and the bacterial growth curve
In higher organisms, growth means increase in size and volume of the organism whereas in case of bacteria, growth refers to the increase in their […]
Differences between Gram positive and Gram negative bacteria
S.N Gram positive bacteria Gram negative bacteria 1. They retain the color of crystal violet and stain dark blue or purple. They take the color […]
Plasmids, their types and functions
Plasmids are extra-chromosomal DNA. They are circular and double stranded DNA molecules which encode traits that are not essential for bacterial viability (normal growth and […]
Toxins and differences between endotoxins and exotoxins
The chemical substances produced by microorganisms in order to harm the host and cause diseases in them are called toxins. The ability of a microorganism […]