A case of septic arthritis caused by Capnocytophaga canimorsus in an HIV patient

Abstract

Invasive infections caused by Capnocytophaga canimorsus , a Gram-negative rod found in the oral cavity of healthy dogs and cats, are rare but they are increasing worldwide. We report a case of septic arthritis in a native knee joint due to this micro-organism. A 57-year-old man, with a well-controlled chronic HIV infection, attended the Emergency Department because of left knee pain and shivering without measured fever. A knee arthrocentesis and a computed tomography scan were performed, revealing septic arthritis with collections in the left leg posterior musculature. He was admitted to the Infectious Diseases Department for antibiotic treatment. Initial synovial fluid was inoculated in blood culture bottles, and the anaerobic one was positive after 63 h. Gram stain revealed fusiform Gram-negative rods, identified as C. canimorsus by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) directly from the bottle. Identification was confirmed by 16S rRNA sequencing and serotyping was performed by PCR, with serovar A as the outcome. Due to an unfavourable clinical course, the patient required two surgical cleanings and after appropriate antibiotic treatment he was discharged 2 months later.

Hematogenous septic arthritis of a non-prosthetic shoulder caused by Capnocytophaga canimorsus: A case report and review of the literature

“…and finally, by clindamycin p.o. 9 weeks Good clinical evolution [15] 59 Man Waldenström’s disease (Rituximab followed by chronic chlorambucil therapy), Prednisone therapy, Alcohol abuse Close dog exposure Bilateral knees Two-stage revision surgery ¤ Ertapenem i.v. 6 weeks Good clinical and biological evolution [16] 31 Man Small congenital ventricular septal defect Dog bite L4-L5 osteomyelitis/discitis None Nafcillin i.v.…”

Wound infection caused by Pasteurella canis and Neisseria animaloris after a dog bite

“…In fact some infections caused by Pasteurella spp . or Capnocytophaga canimorsus (mouth commensals of dogs or cats) may not be preceded by bites or scratches [ 3 , 4 ].…”

Fatal septic shock and Waterhouse-Friderichsen syndrome caused by serovar B Capnocytophaga canimorsus in an immunocompetent patient. Case report and review

“…One of the cases was also a sepsis by C. canimorsus serovar B ( Table 1 ), as in the case we describe here [ 17 ]. The third patient was an HIV patient with no history of bites who developed a septic arthritis by C. canimorsus serovar A [ 20 ].…”