NAME: Capnocytophaga spp.
SYNONYM OR CROSS REFERENCE: Capnocytophaga ochracea, Capnocytophaga canimorsus, Capnocytophaga cynodegmi, Capnocytophaga gingivalis, Capnocytophaga granulosa, Capnocytophaga haemolytica, Capnocytophaga leadbetteri, Capnocytophaga sputigena Footnote 1-Footnote 3.
CHARACTERISTICS: Capnocytophaga spp., of the family Flavobacteriaceae, are Gram-negative bacteria that appear as long facultative anaerobic rods that are 3-6 µm long. The slender fusiform bacilli are motile through gliding Footnote 2, Footnote 4-Footnote 6. Different morphology may be observed as curved filaments, coccoid, or spindle forms can exist Footnote 7. Strains are capnophlic (e.g. under 5%-10% CO2) and most strains grow well under strict anaerobic conditions. The colour of the colonies may vary from pink to yellowish Footnote 4, Footnote 6.
PATHOGENICITY/TOXICITY: Capnocytophaga is an occasional pathogen found in oral diseases and brain abscesses Footnote 7, Footnote 8. It is a cause of systemic infections in immunocompromised patients, but can also cause disease in immunocompetent patients Footnote 2, Footnote 8. Most of the Capnocytophaga infections that have been reported were contiguous with the oropharynx, including periodontal diseases, ophthalmic lesions, respiratory tract infections, traumatic pericarditis, mediastinal or cervical abscesses, and peritonitis. Mucositis and lesions of the oral mucosal barrier provide a portal of entry for this organism, which can cause septicaemia, endocarditis, peripartum infections, pyonephrosis, osteomyelitis and septic arthritis Footnote 2.
C. canimorsus, which can be transmitted zoonotically, may cause sepsis and other severe infections (endocarditis, osteomyelitis, peritonitis) in immunocompromised patients and rarely in immunocompetent ones Footnote 7, Footnote 9. Patients who present within less than 8h to 12h after a dog bite may show local lesions without significant signs of local inflammation. Later, infection may present with localized cellulitis, pain at the site of injury, a purulent discharge, lymphangitis, and regional lymphadenopathy. Initial symptoms of septicemia may include fever, chills, myalgia, dyspnea, mental confusion, and headache. A fulminant and severe course can occur in immunocompromised persons, characterized by sepsis, meningitis, osteomylitis, peritonitis, endocarditis, pneumonia, purulent arthritis, disseminated intravascular coagulation (DIC) and fulminant purpura but has also been observed in previously healthy persons Footnote 7, Footnote 10.
HOST RANGE: Human, canines, cats, rabbits Footnote 7.
INFECTIOUS DOSE: Unknown.
COMMUNICABILITY: Person-to-person transmission is very rare Footnote 10.
RESERVOIR: C. ochracea, C. gingivalis, C. granulosa, C. haemolytica, C. sputigena and C. leadbetteri are normal inhabitants of the human oral cavity, and especially dental plaque Footnote 2-Footnote 4, Footnote 7. C. canimorsus and C. cynodegmi are part of the oral microbiota of canines and, more rarely, of cats and rabbits Footnote 7, Footnote 9.
DRUG SUSCEPTIBILITY: Capnocytophaga spp. are usually susceptible to macrolides, clindamycin, tetracycline, linezolid, chloramphenicol, imipenem and quinolones Footnote 7.
SUSCEPTIBILITY TO DISINFECTANTS: Susceptable to antiseptic solutions of chlorhexidine or 1% povidone-iodine Footnote 2.
PHYSICAL INACTIVATION: No information specific to this species is available. However, similar organisms have been observed to be susceptible to moist heat (121°C for at least 15 min); dry heat (160-170°C for at least 1 hour); low temperature sterilization (i.e. Ethylene oxide Footnote 11, Footnote 12 or plasma sterilization Footnote 13, Footnote 14).
SURVIVAL OUTSIDE HOST: Unknown.
SURVEILLANCE: Monitor for symptoms. The diagnosis of Capnocytophaga spp. infection is usually made based on the bacterial culture of blood, other body fluids (cerebrospinal fluid) or less frequently from the bite wound or tissue from the bitten individual. The use of enriched media is important for the isolation of Capnocytophaga spp. The organism grows best at 35 to 37 ºC in an aerobic atmosphere plus 5 to 10 % CO2 or anaerobically Footnote 7, Footnote 10.
Note: All diagnostic methods are not necessarily available in all countries.
first AID/TREATMENT: Administer proper antibiotic therapy Footnote 2, Footnote 7. Therapy with amoxicillin-clavulanate should be initiated immediately when infection with C. canimorsus is suspected. This therapy must be particularly used for splenectomized or immunocompromised patients after a dog or a cat bite Footnote 7.
PROPHYLAXIS: Cleaning any animal bite wound with an antiseptic, prophylactic treatment with antibiotic may be prescribed Footnote 10.
LABORATORY-ACQUIRED INFECTIONS: No cases have been reported.
SOURCES/SPECIMENS: Blood, cerebrospinal fluid, saliva samples from humans, dogs or cats Footnote 10.
PRIMARY HAZARDS: Accidental parenteral inoculation.
RISK GROUP CLASSIFICATION: Risk group 2. This risk group applies to the genus as a whole, and may not apply to every species within the genus.
CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infected or potentially infected materials, animals, or cultures. These containment requirements apply to the genus as a whole, and may not apply to each species within the genus.
PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes Footnote 15.
OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities Footnote 15.
SPILLS: Allow aerosols to settle and, wearing protective clothing, gently cover spill with paper towels and apply an appropriate disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up Footnote 15.
DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism before disposing by autoclave, chemical disinfection, gamma irradiation, or incineration Footnote 15.
STORAGE: The infectious agent should be stored in leak-proof containers that are appropriately labelled Footnote 15.
REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.
UPDATED: December, 2011
PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada.
Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.
Public Health Agency of Canada, 2011