Virulence factors of Listeria monocytogenes 1. Adhesion proteins (Ami, Fbp A, flagellin) Mediate bacterial binding to host cell that contribute to virulence. 2. Listeriolysin O A hemolytic and cytotoxic toxin that allows for survival within phagocytes. 3. Internalin Cell surface protein … Read more
Pathogenesis of Francisella tularensis Francisella tularensis is carried by many species of wild rodents, rabbits, beavers. Humans become infected by handling the carcasses or skin of infected animals, by inhaling infective aerosols or ingesting contaminated water, through insect vectors and … Read more
Pathogenesis of Chlamydia trachomatis Chlamydia are acquired by direct contact with mucous membranes or abraded skin, that is, by sexual contact or by direct inoculation into the eye in the case of trachoma or neonatal conjunctivitis. Two forms of the … Read more
Virulence factors of Streptococcus pyogenes A. Antigenic structure M protein: rod like coiled structure with two major structural classes; Class I and Class II ;major virulence factor;resist phagocytosis and intracellular killing by polymorphonuclear leukocytes in the absence of antibodies. B. … Read more
Pathogenesis of Corynebacterium diphtheriae In nature, C diphtheriae occurs in the respiratory tract, in wounds, or on the skin of infected persons or normal carriers. It is spread by droplets or by contact to susceptible individuals; the bacilli then grow … Read more
Pathogenesis of Gardenerella vaginalis A. Adherence of G. vaginalis to Host Epithelium: Initial Steps in Invasion The initial steps of establishing infection include adherence to host receptor sites, production of cytotoxic substances specific for host cells, and biofilm formation. vaginais … Read more
Virulence factors or antigenic structures of Neisseria gonorrhoeae A. Pili Pili are the hair like appendages that extend up to several micrometers from the gonococcal surface. It mediates the exchange of genetic material between strains and attachment to human mucosal … Read more
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 and activates alternative complement pathway Protein adhesion – binds to … Read more
Pathogenesis of Coxiella burnetii Human infection usually follows inhalation of aerosols containing C. burnetii. It is estimated that only between 1 and 10 bacteria are necessary to cause infection. C. burnetii has also been known to enter the body via other mucous … Read more
Pathogenesis of Leptospira interrogans Leptospires usually enter the body through the mucous membranes of the upper respiratory tract or the conjunctivae, or through abraded skin, following exposure to contaminated water, infected urine or animal tissues. Ingestion is considered to be … Read more
Pathogenesis of Lyme disease caused by Borrelia burgdorferi Lyme disease is caused by the spirochete B. burgdorferi, which is transmitted by the bite of a small tick of the genus Ixodes. Humans are “accidental” hosts for B. burgdorferi because spirochetes from infected … Read more
Pathogenesis of Treponema pallidum The two major routes of transmission of Treponema pallidum are sexual and transplacental. Sexual exposure to a person who has an active syphilitic chancre carries a high probability of acquiring syphilis. The organisms enter a susceptible … Read more
Virulence factors of Legionella pneumophila Heat shock protein 60: enhances invasion and cytokine expression in macrophages. Outer membrane protein: binding with and delivery of packaged materials into the eukaryotic cells. inhibit the fusion of phagosomes with lysosomes. Macrophage infectivity potentiator (Mip) … Read more