Capnocytophaga cynodegmi is a gram-negative, fusiform-shaped bacilli with one rounded end and one tapered end. The organism has no flagella, but moves by gliding motility. This organism is found in association with animal and human hosts. It is part of the normal oral flora of dogs, and can be responsible for localized wound infections in humans after dog bites. The spectrum of the infection ranges from a mild local infection at the site of the dog bite to pneumonia, endocarditis, and meningitis. Usually, C. cynodegmi can be controlled by penicillin and penicillin derivatives when infection in humans occur.
C. cynodegmi is a slow or poorly growing organism. It is a facultative anaerobe and can grow in the air with 5% carbon dioxide. It is a chemoorganotroph that uses carbohydrates as substrates, or it can ferment glucose. The organism is very fastidious, making it difficult to cultivate in the laboratory. Various techniques have been developed to promote their growth, such as the addition of serum to the fermentation medium to enhance growth. Identification of the organism is possible by detecting the reactions in fermentation. These bacteria are capnophiles, requiring extra carbon dioxide for their growth.
It is difficult to distinguish Capnocytophaga canimorsus and Capnocytophaga cynodegmi, but for most clinical purposes, the identification of the genus is sufficient enough for treatment and precludes the need to identify the species. Both of these species are yellow-pigmented, thin, gram-negative rods with tapered ends that move by gliding and will not grow in ambient air.
Capnocytophaga cynodegmi's physiologic or biochemical characteristics include growth in the presence of oxidase and catalase. It does not produce indole, reduce nitrate, or ferment xylose.
References:
Forbes, Betty, Daniel Sahm, and Alice Weissfeld. Bailey and Scott's Diagnostic Microbiology,
10th Ed., Mosby Pub., 1998.
Bergey's Manual of Systematic Bacteriology", Vol. 3, Williams and Wilkins, 1989.
The Prokaryotes", Volume IV, Second Edition, Springer-Verlog, 1992.
*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.
Return to Missouri S&T Microbiology HomePage Go to DJW's HomePage
This Document is maintained by djwesten@ mst.edu
