Question

What are some characteristics of the pathogen, Citrobacter freundii, that increase its virulence?

Answer 1

Citrobacter freundii is a facultative anaerobic gram negative bacteria. It is a common commensal of gut microbiome of humans, but it act as oppurchunstic pathogen. Citrobacter freundii cause oppurchunstic nosocomial infections of respiratory tract, urinary and blood. Some Citrobacter freundii cause food poisoning and diarrhea.

The main virulence factors of Citrobacter freundii that cause diarrhea are toxins including Shiga like toxins, heat stable toxins and a cholera toxin B homolog. The toxins released by bacteria helps to manipulate host cell functions and to withstand host immune response. These toxins increase the virulence of bacteria.

Citrobacter freundii causes neonatal meningitis and have a tendency to cause brain abscess. The Citrobacter freundii can penetrate human blood brain barrier to reach meninges.