Anaerobic Culture Tips

Common anaerobic pathogens include Actinomyces sp., Clostridium perfringens, Fusobacterium necrophorum and Bacteroides fragilis. Oftentimes, ordering an anaerobic culture can be overlooked. Situations where an anaerobic culture may be indicated are discussed below:

  • Abdominal abscesses: numerous anaerobic organisms are considered normal enteric flora. If your animal has an abdominal abscess, it is possible that an anaerobe gained access to an area it shouldn’t be.
  • Oral abscesses: again, anaerobes make up a significant portion of animal’s normal flora. Following any type of oral trauma or dental decay, these normal anaerobe organisms can invade a new area and begin to cause problems.
  • Sterile body fluid-Generally, infections are monomicrobial. However, due to the invasive nature of collection, it may be beneficial to order the anaerobic culture right away so as to not have to collect a second sample.
  • If you are highly suspicious of a bacterial infection but the routine aerobic culture results are ‘No Growth.’
  • Does your sample contain gritty, sand-like particles? It could be a sign of Actinomycosis.
  • High amounts of gas production or foul odors.
  • Hemorrhagic (dark red, bloody in appearance) intestines may be a sign of Clostridium perfringens overgrowth.

If an anaerobic culture is warranted, please send your sample in an anaerobic transport vial or Amies gel tube and transport to the lab as quickly as possible. Anaerobic organisms are sensitive to oxygen and will rapidly deteriorate without the appropriate conditions.

For more information on all things microbiology at the NDSU-VDL, please visit our Microbiology page!

Image credits:

Featured Image: Public Health Image Library #21914; 3D image of C. perfringens.

Clostridium perfringens on blood agar (double zone hemolysis around colonies); Sarah Gefroh, Diagnostic Microbiologist