Biocheminsider

By Prof Moses Joloba Principle Some bacteria have the ability to hydrolyse (breakdown in presence of water) urea to NH3 and CO2, as they can produce the enzyme ‘urease’. NH3 is alkaline (basic), due to which, it increases the pH changing the color of phenol red from yellow to pink. In the urease test, the test bacteria … Read more

By Prof Moses Joloba Introduction The indole test is a biochemical test performed on bacterial species to determine the ability of the organism to convert tryptophan into indole. This division is performed by a chain of a number of different intracellular enzymes, a system generally referred to as “tryptophanase.” Indole is generated by reductive deamination from tryptophan via the intermediate molecule indolepyruvic acid. Tryptophanase catalyzes the deamination … Read more

By Prof Moses Joloba Principle Some bacteria have the ability to utilize glucose and convert it to a stable acid like lactic acid, acetic acid or formic acid as the end product.These bacteria initially metabolise glucose to pyruvic acid, which is further metabolized through the ‘mixed acid pathway to produce the stable acid. The type … Read more

By Prof Moses Joloba Introduction Gram staining is the most important differential staining method used in microbiology. 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 bacteria and gram-negative bacteria. The name comes from the Danish bacteriologist Hans Christian Gram, who developed the technique. 1) Gram-positive Bacteria: … Read more

By Prof Moses Joloba Objective The Objective of capsule staining is to observe bacterial capsule by distinguishing capsular material from the bacteria cell.In some bacteria, the cell wall is surrounded by a viscous cell envelope called ‘capsule’. It is made of polysaccharide, glycoprotein or polypeptide.When the capsule is too thin to be observed under light … Read more

By Prof Mariam Mirambo Elements Of Comparison Staphylococcus Streptococcus Cellular Arrangement Spherical cells in clusters (grape like clusters). Spherical or ovoid cells in chains or pairs. Fission/Division Irregular division in all three planes. Division in one linear direction. Catalase Test Positive (Presence of catalase enzyme) Negative Halotolerance Halotolerant. Can tolerate upto 8% salt concentration. Inhibited … Read more

By Prof Mariam Mirambo Gram Positive Bacteria Gram-positive bacteria are bacteria with thick cell walls. In a Gram stain test, these organisms yield a positive result. The test, which involves a chemical dye, stains the bacterium’s cell wall purple. Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through … Read more

By Prof Mariam Mirambo Elements Of Comparison Plasmodium vivax Plasmodium falciparum Causes Benign tertian malaria Malignant tertian malaria Prevalence Tropics, Africa (rare in West Africa), Middle East, Asia, Central and South America. It is the most common geographically widespread species of Plasmodium causing malaria in human beings. Predominant species, worldwide tropics, but especially sub-Saharan Africa. Inversion Of … Read more

Reviewed By: Prof Mariam Mirambo Acinetobacter baumannii is a type of gram-negative bacteria that has emerged as a significant nosocomial (hospital-acquired) pathogen, particularly affecting individuals with compromised immune systems, such as those in intensive care units (ICUs). It is known for its ability to survive in harsh environments and its resistance to many commonly used … Read more