Chlamydophila felis
A Microbial Biorealm page on the genus Chlamydophila felis
Classification
Higher order taxa
Domain: Bacteria, Phylum: Chlamydiae, Class/Order: Chlamydiales, Family: Chlamydiaceae, Genus: Chlamydophila, Species: C. felis (Chlamydophila, 1).
Description and significance
The Chlamydophila felis bacteria appear to be rod shaped organisms with a rigid lipid containing cell wall. Chlamydophila felis are similar to gram-negative bacteria (Tozon, 1). The organism’s habitat is mainly within cats, but there have been known cases detected in humans. This organism was first discovered in 1944 by Baker. The bacterium was isolated from cats affected by pneumonia, a common symptom of Chlamydophila felis (Chlamydial, 1). It was important enough to have its genome sequenced because Chlamydophila felis can provide information for comprehension of diseases and elucidation of the chlamydial evolution (Azuma, 2).
Genome structure
The Chlamydophila felis genome is composed of a circular 1,166,239 bp chromosome which encodes 1005 protein-coding genes. It also contains a 7552 bp circular plasmid (Azuma, 1). The circular plasmid is important because it makes the bacteria virulent. Strains such as FP Pring and FP Cello contain plasmids. These strains can produce a lethal disease in mice. In addition, there is also an FP Baker strain which does not contain a plasmid and cannot produce any disease in mice. These FP Baker strains are used as live vaccines for cats (Chlamydophila, 1). Furthermore, by comparing the Chlamydophila felis genome with other Chlamydia species, it is observed that 795 genes are in common with the family Chlamydiaceae species and only 47 genes are specific to Chlamydophila felis. By analysis of common genes most exhibit a similar divergent pattern, but 14 C. felis genes accumulated more mutations, suggesting that these genes may be involved in the evolutional adaptation to the Chlamydophila felis specific niche (Azuma, 1-2).
Cell structure and metabolism
Chlamydophila felis is a coccoid bacterium which is rod shaped. It has a rigid lipid containing cell wall and is similar in structure and content to the wall of a gram-negative bacterium. This means that it has a thin cell wall and an inner and outer cell memebrane. Chlamydophila felis also contains nuclear DNA and RNA but cannot replicate and survive on its own in the environment (Tozon, 1). To gain energy, the Chlamydophila felis bacterium metabolizes pyruvate, purine, pyrimidine, nicotinate, nicotinamide, glutamate, cystein, and glyoxylate through various metabolic pathways (Kegg, 1).
Ecology
Chlamydophila felis interacts with eukaryotic organisms, mainly with cats but, it can also interact with human hosts as well. The bacterium multiplies within host epithelial cells, eventually causing the cell to lyse and release many more new infectious bodies, which can go on to start new developmental cycles and infect more cells (A1062, 1). The Chlamydophila felis bacteria have no direct impacts on outside environments because it can not survive on its own without a host (Tozon, 1). The bacterium can however indirectly impact the environment by infecting cats and some people with its disease. Thus, by interaction with infected individuals in the outside environment, the bacteria can be transferred from a host environment and infect more new hosts.
Pathology
Chlamydophila felis is spread by direct contact between cats or cats and people. It causes disease by targeting the conjunctival epithelium of the eye. The organisms replicate in the cytoplasm of these epithelial cells and eventually cause the cells to rupture, which releases the infectious bodies so they can go on to infect other epithelial cells and eventually spread throughout the body (A1062, 1). The symptoms of Chlamydophila felis include watery discharge from the eye, blinking, red and swollen conjunctivae, mild nasal discharge and sneezing, mild fever, lethargy, inappetence, pnemonitis, and may be a cause of infertility in cats (HAMAP, 1).
Application to Biotechnology
This organism, as well as related species, produces no known compounds or enzymes that would be useful in biotechnology.
Current Research
There has been some current research concerning Chlamydophila felis in the last few years. One research project used real-time PCR to monitor the C. felis infection and its response to antibiotic treatment such as doxycycline (Dean, 1-2). Another research project took serum samples from 214 cats with no signs of the disease and analyzed them for the presence of antibodies against Chlamydophila felis. The results stated that the prevalence of antibodies against Chlamydophila felis was 11% with no significant difference between purebred and mixed cat breeds (Holst, 1-2). In addition another research project tested enrolfoxacin (a new treatment for Chlamydophila felis) and its efficiency in comparison with doxycycline (the existing treatment for Chlamydophila felis) in the treatment of Chlamydophila felis infection in cats. Both treatment groups showed equal improvements in the clinical signs of the Chlamydophila felis infection and no side effects were observed in the cats treated with enrofloxacin (Gerhardt, 1-2).
References
Azuma, Y., Hirakawa, H., Yamashita, A., Cai, Y., Rahman, MA., Suzuki, H., Mitaku, S., Toh, H., Goto, S., Murakami, T., Sugi, K., Hayahi, H., Fukushi, H., Hattori, M., Kuhara, S., Shirai, M. “Genome sequence of the cat pathogen, Chlamydophila felis”. DNA Research. 2006. Volume 13. Isuue 1. p. 15-23.
“A1062-Chlamydophila Felis”. Health Gene. Date: April 30 2007. <http://www.healthgene.com/vet/a1062.asp>.
“Chlamydial infections in animals, Chlamydophila felis: Introduction”. Date: April 30 2007. <http://www.chlamydiae.com/restricted/docs/infections/vet_cfelis_introduction.asp> .
“Chlamydophila felis”. Wikipedia, the free enclycopedia. Date: April 30 2007. <http://enwikipedia.org/wiki/Chlamydophila_felis>.
Dean, R., Harley, R., Helps, C., Caney, S., Gruffydd-Jones, T. “Use of quantitative real-time PCR to monitor the response of Chlamydophila felis infection to doxycycline treatment”. Journal of Clinical Microbiology. 2005. Volume 43. Issue 4. p. 1858-1864.
Gergardt, N., Schulz, BS., Werckenthin, C., Hartmann, K. “Pharmacokinetics of enrofloxacin and its efficiency in comparison with doxycycline in the treatment of Chlamydophila felis infection in cats with conjunctivitis”. The Veterinary Record. 2006. Volume 159. Issue 18. p. 591-594.
“HAMAP: Chlamydophila felis (strain Fe/C-56) complete proteome” Date: April 30 2007. <http://expasy.org/sprot/hamap/CHLFF.html>.
Holst, BS., Englund, L., Palacios, S., Renstrom, L., Berndtsson, LT. “Prevalence of antibodies against feline coronavirus and Chlamydophila felis in Swedish Cats”. Journal of Feline Medicine. 2006. Volume 8. Issue 3. p. 207-211.
Tozon, N., Suhadolc-Scholten, S., Pavlin, D., Dovc, A. “Chlaymdophila felis infection in cats-clinical cases”. Slov Vet Res. 2006. Volume 43. Issue 2. p. 109-114.
Edited by Roseanna Iverson student of Rachel Larsen and Kit Pogliano
