Capnocytophaga cynodegmi Cellulitis, Bacteremia, and Pneumonitis in a Diabetic Man

Abstract

Capnocytophaga cynodegmi (formerly "DF-2 like organism"), a commensal organism of the canine oral cavity, is a capnophilic, gram-negative, facultative bacillus. C. cynodegmi has rarely been encountered in human diseases. We report the first known case of cellulitis, bacteremia, and pneumonitis caused by C. cynodegmi in a diabetic man from central India following a dog bite. CASE REPORTA 59-year-old non-insulin-dependent diabetic man was hospitalized with a 24-h history of fever, purulent expectoration, and painful leg swelling. Two days earlier, he had been bitten by a stray dog. Immediately after the bite, the wound was cleaned, tetanus prophylaxis was administered, and an antirabies immunization schedule was initiated. On examination, he was toxic, febrile, tachypneic, and hypotensive, with signs of lower left lobe pneumonitis. Cellulitis over the ankle and the lower third of the left leg, pus discharge from the puncture wound, and regional lymphadenopathy were noticed. His hemoglobin was 122 g/liter, and his total white-cell count was 12.2 ϫ 10 9 /liter (80% polymorphs, 10% bands). A chest radiograph revealed left perihilar pneumonitis. Ankle and leg radiographs showed soft tissue swelling with no bone involvement. Blood glucose (random sample) was 21 mmol/liter (378 mg/dl). Echocardiography and renal and hepatic function test results were normal. Incision and drainage of the wound yielded 30 ml of pus. Penicillin, ciprofloxacin, gentamicin, metronidazole, saline, and crystalline insulin were administered intravenously. Over the next 5 days, the patient exhibited fluctuations of temperature (38.5 to 40°C) and remained ill. Three days after the initial collection and incubation, the blood, bronchoalveolar lavage fluid, sputum, and pus specimens obtained for culture yielded a capnophilic, gram-negative, facultative anaerobic bacillus that was positive for oxidase and catalase. Species identification of Capnocytophaga cynodegmi was based on the criteria of Brenner et al. (2). Punctate colonies of less than 1 mm in diameter were noted after 72 h on chocolate agar in 5% CO 2 . The colonies appeared convex and smooth, exhibited confluent growth, and increased in size to 3 mm 120 h after initial incubation. The bacteria were gram negative, and they appeared as thin, 2-to 4-mm-long fusiform bacilli with slightly curved ends. The isolate was microaerophilic and exhibited luxuriant growth on heart infusion agar supplemented with 5% sheep blood and incubated at 35 to 72°C in the presence of 5% CO 2 (candle extinction jar). The organism was identified as C. cynodegmi and was differentiated from Capnocytophaga canimorsus by its ability to ferment sucrose, raffinose, xylose, and inulin and by its growth at 72°C. The isolate had gliding mobility, showed beta-hemolysis on blood agar with 5% rabbit blood, was positive for catalase, oxidase, arginine dihydrolase, O-nitrophenyl-␤-D-galactopyranoside, and esculin, and produced acid from cellobiose, dextrin, fructose, D-glucose, glycogen, lactose, maltose, D-mannose, melibiose, D...

Molecular Characterization of Capnocytophaga canimorsus and Other Canine Capnocytophaga spp. and Assessment by PCR of Their Frequencies in Dogs

“…one patient with a wound infection (9) and two cases of bacteremia (11,20) with this species have been described. In the latter two cases, only biochemical determination was performed; one of the two strains was identified only on the basis of a positive nitrate test, which is not a common feature of this species.…”

Capnocytophaga cynodegmi Peritonitis in a Peritoneal Dialysis Patient

“…C. canimorsus has been reported to be sensitive to penicillin, ampicillin, piperacillin, ofloxacin, cefuroxime, cefotaxime, imipenem, erythromycin, and clindamycin (2, 13). Sarma and Mohanty (12) reported that their isolate of C. cynodegmi was sensitive to penicillin, amoxicillin, ofloxacin, cefuroxime, cefotaxime, ceftazidime, ceftriaxone, erythromycin, clindamycin, and vancomycin. By using a nonstandardized method, our isolate of C. cynodegmi seemed to be sensitive to penicillin, ampicillin, piperacillin-tazobactam, cefuroxime, cefotaxime, meropenem, tetracycline, and rifampin and resistant to erythromycin and gentamicin (Table 1).…”

“…It is well-known that C. canimorsus may cause fulminant septicemia, disseminated intravascular coagulation, meningitis, and endocarditis, often in splenectomized patients (7,11), while C. cynodegmi seems to cause more localized infections. The reported cases of C. cynodegmi infections in humans include five cases of localized wound infections, most resulting from dog bites or cat scratches (1); localized cellulitis following a bite by her cat in a patient with diabetes and rheumatoid arthritis treated with prednisolone and a tumor necrosis factor alpha blocking agent (9); cellulitis with pus discharge from puncture wounds and regional lymphadenopathy, pneumonitis, and bacteremia in a diabetic patient who had been bitten by a dog (12); and fatal fulminant sepsis with disseminated intravascular coagulation and meningitis in a patient with diabetes who had been previously splenectomized and bitten by a dog (8). In the latter case, C. cynodegmi was differentiated from C. canimorsus by a nitrate reduction reaction only, leaving doubt concerning a correct species identification.…”

Capnocytophaga cynodegmi in a Rottweiler Dog with Severe Bronchitis and Foreign-Body Pneumonia

“…Other local infections such as keratitis can occur (8,14). Systemic infections such as meningoencephalitis and generalized sepsis have been reported in splenectomized patients, as well as those with predisposing conditions such as diabetes, alcoholism, and cirrhosis (3,5,14,20). Recently a C. cynodegmi respiratory infection was reported in a cat with underlying pulmonary neoplasia (7).…”

“…cynodegmi, formerly known as CDC dysgonic fermenter-2-like, is a fastidious aerobic, capnophilic, gram-negative, fusiform bacillus that is about 2 to 4 m long and can be slightly curved at the end (1,3,5,11,13,14,16,20). The name cynodegmi is derived from the Greek kyno (dog) and degmos (bite).…”