How viruses cause disease?
Viruses gain access to the host through skin and mucous membranes, and via the respiratory, gastrointestinal, and genital tracts. Their virulence or lack of it may be determined by very … Read more
Sagar Aryal, PhD
Laboratory diagnosis, Treatment and Prevention of Streptococcus pneumoniae
Laboratory diagnosis of Streptococcus pneumoniae Specimen: Sputum, blood, endotracheal aspirate, bronchoalveolar lavage, cerebrospinal fluid (CSF), pleural fluid, joint fluid, abscess fluid, bones, and other biopsy material. Microscopy Gram staining of … Read more
Virulence factors, Pathogenesis and Clinical manifestations of Streptococcus pneumoniae
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
Factors affecting bacterial pathogenicity
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
Biochemical Test of Serratia marcescens ÂBasic 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
Light Microscope vs Electron Microscope- 36 Major Differences
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
Yeast Artificial Chromosomes (YACs)
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
Viruses- Structure, Replication and Diagnosis
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, treatment and prevention of Rickettsia rickettsii
Laboratory diagnosis of Rickettsia rickettsii Specimen:Â 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
Biochemical Test of Enterococcus faecalis
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