Tag: Pathogenesis

Virulence factors, Pathogenesis and Clinical manifestations of Streptococcus pneumoniae 4.44/5 (9)

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 and activates alternative complement pathway Protein adhesion – binds to epithelial cells Peptidogylcan – activates alternative complement pathway Phosphorylcholine – mediates invasion of host cell […]

Pathogenesis and Clinical manifestations of Francisella tularensis 4.89/5 (9)

Pathogenesis and Clinical manifestations of Francisella tularensis

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 by being bitten by carnivores that have themselves eaten infected animals. Humans are infected by […]

Pathogenesis and Clinical manifestations of Corynebacterium diphtheriae 4.88/5 (8)

Pathogenesis and Clinical manifestations of Corynebacterium diphtheriae

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 on mucous membranes or in skin abrasions, and those that are toxigenic start producing toxin. […]

Virulence factors, Pathogenesis and Clinical manifestations of Listeria monocytogenes 4.55/5 (11)

Listeria monocytogenes

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 that induces phagocytosis. 4. Act A Induces actin polymerization on the surface of host cells, […]

Pathogenesis and Clinical manifestations of Treponema pallidum 4.65/5 (17)

Pathogenesis and Clinical manifestations of Treponema pallidum

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 host by penetration of intact mucous membranes or the minute abrasions in the skin surface […]

Pathogenesis and Clinical manifestation of Gardenerella vaginalis 4.76/5 (21)

Pathogenesis and Clinical manifestation of Gardenerella vaginalis

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  produces  vaginolysin, a cholesterol-dependent cytolysin, for human cells and encodes a pore-forming toxin that binds […]

Pathogenesis and Clinical manifestation of Mycobacterium tuberculosis 4.5/5 (20)

Pathogenesis and Clinical manifestation of Mycobacterium tuberculosis

Virulence factors of Mycobacterium tuberculosis A. Mycolic acid and Lipoarabinomannan (LAM) Waxy layer that protects the bacteria from many host factors and also to many antibiotics including beta lactamases. Muramyl dipeptide (from peptidoglycan) complexed with mycolic acids can cause granuloma formation, phospholipids induce caseous necrosis. LAM is structurally and functionally related to the O antigenic […]

Pathogenesis and Clinical Manifestation of Neisseria gonorrhoeae 4.88/5 (17)

Pathogenesis and Clinical Manifestation of Neisseria gonorrhoeae

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 cell surface, invasion of host cells, and survival through the inhibition of phagocytosis. Two types: […]

Virulence factors and Clinical manifestation of Staphylococcus aureus 4.85/5 (13)

Virulence factors and Clinical manifestation of Staphylococcus aureus

Virulence factors of Staphylococcus aureus A. Cell wall components Polysaccharide Capsule: inhibits phagocytosis Peptidoglycan: activates complement, IL-1, chemotactic to PMNs Teichoic acid: species specific, mediate binding to fibronectin Protein A: It binds to the Fc region of IgG and complement ,exerting an anti-opsonin effect. Fibronectin binding protein(FnBP): promote binding to ,mucosal cells and tissue matrices. […]

Clinical manifestation and Pathogenesis of Streptococcus pyogenes 4.75/5 (12)

Clinical manifestation and Pathogenesis of Streptococcus pyogenes

Clinical manifestation and Pathogenesis of Streptococcus pyogenes 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. Toxins and enzymes Streptokinase It is also called […]

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