Enteropathogens: Bacterial Virulence Factors

Enteropathogens

Campylobacter virulence factors

• Flagella: Campylobacter's flagella allow for motility, invasion, and colonization of the intestinal epithelium.
• Adhesins: Campylobacter's adhesins (e.g., CadF, FlpA) facilitate binding to epithelial cells.
• Cytotoxins: Campylobacter's cytotoxins (e.g., CdtA, CdtB, CdtC) induce cellular damage and inflammation.
• Capsule: Campylobacter's capsule prevents complement-mediated killing and phagocytosis.

Vibrio cholerae transmission

• Contaminated food and water: V. cholerae is primarily transmitted through ingestion of contaminated food and water.
• Fecal-oral route: The bacterium is shed in the feces of infected individuals and can contaminate food and water sources.
• Person-to-person transmission: V. cholerae can also be transmitted through direct contact with an infected person's feces.

Shigella toxin production

• Shiga toxin: Shigella produces Shiga toxin, a potent cytotoxin that inhibits protein synthesis and induces cell death.
• Toxin production: Shigella toxin production is regulated by the bacterium's iron availability and pH.
• Toxin mechanisms: Shiga toxin disrupts the intestinal epithelial barrier, leading to inflammation and diarrhea.

Salmonella pathogenesis

• Invasion: Salmonella invades intestinal epithelial cells, using type III secretion systems to deliver effector proteins.
• Intracellular survival: Salmonella survives and replicates within host cells, evading immune responses.
• Inflammation: Salmonella triggers an inflammatory response, leading to tissue damage and diarrhea.

Aeromonas virulence mechanisms

• Adhesins: Aeromonas produces adhesins that facilitate binding to host cells and tissues.
• Toxins: Aeromonas produces cytotoxins, hemolysins, and enterotoxins that contribute to tissue damage and diarrhea.
• Biofilm formation: Aeromonas forms biofilms, which enhance its ability to adhere to surfaces and resist antimicrobial agents.