Sagar Aryal, PhD 
Virulence factors of Streptococcus pneumoniae Polysaccharide capsule The capsule is antiphagocytic, inhibiting complement deposition and phagocytosis. 2. Cell wall associated polymers and proteins Teichoic acid – binds to epithelial cells … Read more
A microbe that is capable of causing disease is referred to as a pathogen. Pathogenicity is the ability of a microorganism to cause disease in another organism, namely the host. Pathogens vary in … Read more
Biochemical Test of Serratia marcescens Basic Characteristics Properties (Serratia marcescens) Capsule Negative (-ve) Catalase Positive (+ve) Citrate Positive (+ve) Flagella Positive (+ve) Gas Variable Gelatin Hydrolysis Positive (+ve) Gram Staining … Read more
Both light microscopes and electron microscopes use radiation (light or electron beams) to form larger and more detailed images of objects which cannot be seen clearly through an unaided eye. Light Microscope … Read more
Image Source: https://orbitbiotech.com and https://en.wikibooks.org Structure of Yeast Artificial Chromosomes A yeast artificial chromosome cloning vector consists of two copies of a yeast telomeric sequence (telomeres are the sequences at the ends … Read more
Structure of Virus LIPID ENVELOPE Usually formed from a lipid bilayer taken from their host, into which the virus inserts its own glycoproteins (enveloped virus). Not all viruses have envelopes … Read more
Laboratory diagnosis of Rickettsia rickettsii Specimen: Skin biopsies, serum Direct detection method Although Rickettsiae stain poorly with Gram stain, they can be stained with Giemsa or Gimenez stains. Direct detection of … Read more
Basic Characteristics Properties (Enterococcus faecalis ) Bile Resistance Resistance to 40% (v/v) bile Capsule Negative (-ve) Catalase Negative (-ve) Citrate Negative (-ve) Flagella Negative (-ve) Gelatin Hydrolysis Variable Gram Staining … Read more
Differences between antigen and antibody Antibodies are produced by the immune system in response to antigens (material perceived as foreign). The antibody response to a particular antigen is highly specific … Read more
Pathogenesis of Mycobacterium leprae M. leprae is an acid-fast, gram-positive obligate intracellular bacillus that shows tropism for cells of the reticuloendothelial system and peripheral nervous system (notably Schwann cells). Organisms may … Read more
