LRMoore, Univ of Southern Maine
A Microbial Biorealm page on the genus LRMoore, Univ of Southern Maine
Classification
Higher order taxa
Bacteria; Bacteroidetes; Flavobacteriia; Flavobacteriales; Flavobacteriaceae; Capnocytophaga [Use NCBI link to find]
Species
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NCBI: Taxonomy |
'Capnocytophaga canimorsus'
Description and significance
Capnocytophaga canimorsus is a capnophilic (carbon dioxide loving), facultative anaerobic rod shaped Gram-negative1 nonsporeforming bacterium.6 C. canimorsus is a zoonotic agent (causes interspecies infection) that has been isolated from humans following bite wounds, licks, scratches, and general exposure to dogs5, a lesser degree in cats, and rarely rabbits.1 The bacterium was first isolated in 1976 from a human following a dog bite and was initially named CDC group dysgenic fermenter DF-2 until 1989 it was given its current name.1,6 Millions of people worldwide suffer from animal bites. It has been estimated that out of the 50% of Americans who will be bitten by an animal in their lifetime, 90% of the bites will be inflicted by both dogs and cats.1
C. canimorsus has been documented to cause wound and systemic infection in humans. Although between the years 1976-2010 only 200 cases of Capnocytophaga infection were reported, severe clinical symptoms span a wide range including, but not limited to, septicemia, meningitis, osteomylitis, peritonitis, and endocarditis.1 If exposed to the bacterium, immunocompromised, asplenic, alcoholic, aged, and chronically diseased individuals are at higher risk of contracting infection even though infection has been observed in healthy individuals.1 Exposure and identification of C. canimorsus has proven difficult due to its fastidious nature, but recent PCR-restriction fragment length polymorphism (PCR-RFLP) species specific methods have detected the commensal bacterium in the oral flora of 74% of dogs.2
According to a 2011-2012 American Pet Products Association survey there are 78.2 million dogs and 86.4 million cats owned in the United States alone which does not account for strays or shelter animals.3 The sheer number of dogs and cats warrants the study and characterization of C. canimorsus and other potential zoonotic microbes that make their home living commensally on household pets.
Genome structure
The genome of C. canimorsus Cc5, a strain isolated from a human sepsis patient, consists of a single circular replicon of 2,571,406 base pair, a guanine and cytosine content of 36.11%, and 2,405 coding sequences.4 The genome contains 46 tRNAs, three sets of rRNA, an RNase P, two tmRNAs, a TPP riboswitch, an SRP, a CRISPR region, and 206 lipoprotein genes.4
