Online microbiology and biology related notes by SAGAR ARYAL
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 their ability to produce disease. The measurement of pathogenicity is called virulence, with highly virulent pathogens being more likely to cause disease … Read moreFactors affecting bacterial pathogenicity
Enteroaggregative E. coli (EAEC) Enteroaggregative E. coli (EAEC) are a heterogeneous collection of strains characterized by their autoagglutination in a “stacked-brick” arrangement over the epithelium of the small intestine and, in some cases, the colon. EAEC strains are currently defined as E. coli strains that do not secrete enterotoxins LT or ST and that adhere to HEp-2 … Read moreEnteroaggregative E. coli (EAEC)
Enteropathogenic Escherichia coli (EPEC) Two groups of E. coli are responsible for enteric disease: Enteropathogenic E. coli [EPEC] and some Shiga toxin–producing E. coli [STEC]. They both possess a cluster of virulence genes located on a chromosomal pathogenicity island called the locus of enterocyte effacement (LEE). The EPEC are however, defined by: Presence of LEE and Absence … Read moreEnteropathogenic Escherichia coli (EPEC)
E. coli Pathotypes- ETEC, EPEC, EHEC, EAEC, EIEC, DAEC Escherichia coli (commonly abbreviated E. coli) is a Gram-negative, facultative anaerobic, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms (endotherms). Human Escherichia coli strains are classified as commensal microbiota E. coli, enterovirulent E. coli, and extraintestinal pathogenic E. coli (ExPEC) on the basis of their genetic features … Read moreE. coli Pathotypes- ETEC, EPEC, EHEC, EAEC, EIEC, DAEC
Urinary Tract Infection (UTI)- Types, Causative Agents, Pathogenesis, Symptoms, Complications, Risk Factors, Diagnosis, Treatment and Prevention A urinary tract infection (UTI) is an infection that affects part of the urinary tract. The urinary system is made up of the kidneys, ureters, the urinary bladder, and the urethra. Most UTIs are restricted to infection of the bladder (cystitis), though infection may occur in any area of … Read moreUrinary Tract Infection (UTI)
Methicillin Resistant Staphylococcus aureus (MRSA) MRSA is mediated by mecA gene; which is a chromosomally coded. It alters penicillin binding protein (PBP) present on S. aureus cell membrane to PBP-2a: PBP is an essential protein needed for cell wall synthesis of bacteria. β lactam drugs bind and inhibit this protein, there by inhibiting cell wall … Read moreMethicillin Resistant Staphylococcus aureus (MRSA)
Water Quality Analysis by Most Probable Number (MPN) Most probable number (MPN) analysis is a statistical method based on the random dispersion of microorganisms per volume in a given sample. In this method, measured volumes of water are added to a series of tube containing a liquid indicator growth medium. The media receiving one or … Read moreWater Quality Analysis by Most Probable Number (MPN)
Differences between O Antigen and H Antigen The surface structures of bacteria have considerable antigenic heterogeneity. Often these antigens are used as part of a serologic classification system for the bacteria. The classification of the 2000 or so different Salmonellae is based principally on the types of the O (LPS side chain) and H (flagellar) … Read moreDifferences between O Antigen and H Antigen
Differences between Anthrax bacilli and Anthracoid bacilli The saprophytic organisms which simulate the anthrax bacillus closely, both in their morphological and cultural characters within the group of Gram-positive aerobic sporing bacilli are termed as Anthracoid bacilli. They have a general resemblance to anthrax bacilli such as producing dry wrinkled colonies and in smear, appearing as … Read moreDifferences between Anthrax bacilli and Anthracoid bacilli
Differences between Neisseria meningitidis and Neisseria gonorrhoeae Neisseria meningitidis and Neisseria gonorrhoeae, are obligate human pathogens that cause distinctly different disease syndromes. They are both Gram negative diplococci, non-sporing, oxidase positive and difficult to differentiate on morphological and cultural characteristics. However, they can be differentiated on the following grounds: S.N. Character Neisseria gonorrhoeae Neisseria meningitidis 1. Commonly … Read moreDifferences between Neisseria meningitidis and Neisseria gonorrhoeae