Propionibacterium propionicum
Ryan Rader

Propionibacterium propionicum is a gram-positive, non-motile prokaryote found in the human mouth and cervico-vaginal smears. It was first discovered in 1962 and was first discovered after differentiating it from Actinomyces israelii. The main characteristic of P. propionicum, and the reason for its name, is because it produces propionic acid as an end product of fermentation. Its original name Arachnia propionicus;however, upon 16S RNA sequencing, it was found to be more similar to members of the Propionibacterium genus. The reason why I found this organism interesting was because it is also found in the lacrimal ducts of the eyes and can cause lacrimal canaliculitis. Canaliculitis basically manifests itself as chronic red-eye in one eye due to infection by organisms like P. propionicum and A. israelii. It is diphtheroidal and works both aerobically and anaerobically, but prefers an anaerobic environment. It has the capacity to reduce nitrate and hydrolyze starch while having 63-65% GC content. It has two subtypes and is sensitive for B-lactam antibiotics, tetracyclines, chloramphenicols, and vancomycin.


I found The Prokaryotes at the UMR library to be an invaluable resource because it had much information on the taxonomy, characteristics, and history of this organism. ATCC was less helpful, and its genome has not been mapped yet. I also utilized my Manual of Clinical Microbiology book to locate which organism I wanted to use and to round out the information found.

*Disclaimer - This report was written by a student participaring in a microbiology course at the Missouri University of Science and Technology. The accuracy of the contents of this report is not guaranteed and it is recommended that you seek additional sources of information to verify the contents.


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