Capnocytophaga ochracea

From MicrobeWiki, the student-edited microbiology resource

1. Classification

a. Higher order taxa

Bacteria; Bacteriodetes; Flavobacteriia; Flavobacteriales; Flavobacteriaceae; Capnocytophaga

b. Species

NCBI: Taxonomy

Capnocytophaga ochracea

2. Description and significance

Capnocytophaga ochracea is a gram-negative fusiform-to-rod shaped bacterium that grows in clumps and moves by gliding despite having no flagella (1). This capnophilic aerotolerant anaerobe is found in the oral cavity of humans and contributes to early plaque formation on teeth by being a physical intermediate link between several Streptococcus species and F. nucleatum (2). Dental plaque is associated with periodontal disease and dental caries which is the single most prevalent disease in children (3).

In addition to oral disease, C. ochracea is known to cause sepsis in immunocompromised patients. In immunocompetent patients, intrauterine infections, endocarditis and septic arthritis may occur (4).

3. Genome structure

The genome of C. ochracea strain VPI 2845 consists of 2,612,925 base pairs all within one circular chromosome (5). It has a GC content of 39.59% which equates to 1,034,404 base pairs. The vast majority of the DNA is found in coding regions, 87.76% (5). There are a total of 2,252 genes of which 2,193 (97.38%) are protein-coding genes, 59 (2.62%) are RNA genes. There are a total of 4 rRNA operons (5). 471 (20.91%) of the genes have transmembrane helices which correlate with C. ochracea’s ecological role in the human oral cavity of plaque formation by binding to several bacteria (5).

4. Cell structure

C. ochracea are fusiform rods that form confluent colonies with a halo zone, the outer edge of a colony formed because of gliding (1). C. ochracea does not have flagella but it is still motile via a process called gliding in which the cell moves about its longitudinal axis. As cells glide out from the denser center of the colony, the thickness of cells decreases leading to a halo zone (1). Cells growing in a colony structure grow in an end-to-end fashion. Microcolonies ranging between 50-100 cells have been noticed throughout the entirety of the halo zone which is uncommon for gliding prokaryotes (1).

On the cell surface of C. ochracea, there are adhesin sites that allow for coaggregation between C. ochracea and F. nucleatum, Streptococcus and Actinomyces species (6). Simple sugars, such as L-rhamnose, β-methy-D-galactoside, lactose, and α-methy-D-galactoside, are effective inhibitors of C. ochracea-S. sanguis coaggregation. However, L-rhamnose is the most effective inhibitor of C. ochracea from binding with S. sanguis, A. naeslundii, or A. israelii (6).

5. Metabolic processes

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6. Ecology

Habitat; symbiosis; contributions to the environment.

7. Pathology

How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.

7. Key microorganisms

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8. Current Research

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9. References

It is required that you add at least five primary research articles (in same format as the sample reference below) that corresponds to the info that you added to this page. [Sample reference] Faller, A., and Schleifer, K. "Modified Oxidase and Benzidine Tests for Separation of Staphylococci from Micrococci". Journal of Clinical Microbiology. 1981. Volume 13. p. 1031-1035.