Which bacteria predominate in the colon?

Which bacteria predominate in the colon?

• A. Coliforms, enterococcus, anaerobes, and streptococci
• B. Staphylococcus aureus and Streptococcus
• C. Pseudomonas species
• D. Mycobacteria

Answer: (A)

The main idea is the typical mix of bacteria that normally inhabit the colon. The colon is home to a dense, mostly anaerobic microbial community, so anaerobes are the dominant group. Among the bacteria commonly found there, coliforms (like E. coli) and Enterococcus are frequent residents, and streptococci are also commonly present. Put together, these groups represent the usual composition of colonic flora. Other bacteria such as Staphylococcus aureus, Pseudomonas species, or Mycobacteria can be found under specific conditions or in other body sites, but they do not define the normal dominant flora of the colon.

The main idea is the typical mix of bacteria that normally inhabit the colon. The colon is home to a dense, mostly anaerobic microbial community, so anaerobes are the dominant group. Among the bacteria commonly found there, coliforms (like E. coli) and Enterococcus are frequent residents, and streptococci are also commonly present. Put together, these groups represent the usual composition of colonic flora. Other bacteria such as Staphylococcus aureus, Pseudomonas species, or Mycobacteria can be found under specific conditions or in other body sites, but they do not define the normal dominant flora of the colon.