Improvement of identification of Capnocytophaga canimorsus by matrix-assisted laser desorption ionization-time of flight mass spectrometry using enriched database

Capnocytophaga cynodegmi bacteremia associated with a cat bite in a patient with systemic lupus erythematosus on hemodialysis: A case report

The genus Capnocytophaga, which is part of the oral microbiome of both humans and animals, has the potential to cause severe infections in humans following animal bites. A 59-year-old man with systemic lupus erythematosus (SLE) on hemodialysis presented with cellulitis of the left upper limb after being bitten by his cat and was admitted to our hospital. Blood cultures were obtained, and empiric treatment with ampicillin/sulbactam was initiated. The patient developed a non-severe drug eruption on the 3rd hospital day, prompting a switch to ceftriaxone. Thin spindle-shaped Gram-negative bacilli were isolated from the blood cultures 127 h (5 days and 7 h) after obtained blood sample, and the patient completed a 2-weeks course of ceftriaxone with complete recovery. The isolate was identified as Capnocytophaga cynodegmi by MALDI-TOF MS and 16S rRNA gene sequencing. This case highlights the importance of considering C. cynodegmi in cat bite-associated infections. Obtaining blood cultures and extending incubation periods may be crucial for identifying the causative pathogen and guiding appropriate treatment in such cases.

A case report of Capnocytophaga canimorsus meningitis with failure of ceftriaxone therapy

Background

Capnocytophaga canimorsus is a gram-negative zoonotic organism that has the potential to cause devastating human infection. Historically, treatment with beta-lactams including penicillin and ceftriaxone has been effective.

Methods

We describe a complicated case of C. canimorsus meningitis in a 70-year-old female following a superficial puncture wound from her dog's teeth.

Results

The case described here was complicated by seizures following treatment with ceftriaxone therapy. This case is also the first reported case of C. canimorsus meningitis associated with moyamoya disease and fibromuscular dysplasia.

Conclusions

Physicians should be aware of the possibility of ceftriaxone-resistant C. canimorsus and have a low threshold to broaden antimicrobial coverage in the absence of clinical improvement. We also raise the possibility of an association between vasculopathies and unusual infections like C. canimorsus.

Pet-related bacterial zoonotic infections: Three cases of severe infections in the immunocompromised host

Pets can have many positive effects on their owners. However, close contact with pets offers optimal conditions for transmission of micro-organisms. Especially immunocompromised patients are at risk for zoonotic infections. Here we describe the diagnosis, microbiology and treatment of three patients with severe zoonotic infections with Helicobacter canis, Pasteurella multocida and Capnocytophaga canimorsus. With this case report we would like to emphasize the importance of awareness for pet-related zoonotic infections in immunocompromised patients.

Cat Rearing: A Potential Risk of Fulminant Sepsis Caused by <b><i>Capnocytophaga canimorsus</i></b> in a Hemodialysis Patient

Capnocytophaga canimorsus is a commensal organism colonized in oral flora of dogs and cats and causes severe sepsis through bite wound in immunocompromised patients. To date, hemodialysis has not been reported as a risk of C. canimorsus infection. A 75-year-old woman with end-stage renal disease secondary to hypertension suddenly developed septic shock. She reared 6 cats in her home, but no bite or scratch wound was found on her body. She was empirically treated with piperacillin-tazobactam and temporally received continuous hemodiafiltration. On the fifth day after sampling, blood culture revealed C. canimorsus as the cause of sepsis. After 4 weeks of antibiotic therapy targeting this organism, she recovered from the sepsis and was discharged on the 109th hospitalization day. Hemodialysis patients may be vulnerable to invasion into the blood stream by C. canimorsus due to the presence of punctures in their skin and the impaired immune function associated with uremia. Physicians should consider this organism as a cause of sepsis in hemodialysis patients who rear dogs or cats even in the absence of apparent bite wounds.

Capnocytophaga canimorsus Meningitis: Diagnosis Using Polymerase Chain Reaction Testing and Systematic Review of the Literature

INTRODUCTION

Capnocytophaga canimorsus infections are associated with dog bites, especially in asplenic or immunocompromised patients, and typically manifest as sepsis and/or bacteremia. Meningitis has been rarely described, and its diagnosis may be delayed due to poor or slow growth using traditional culture techniques. We provide our experience using polymerase chain reaction (PCR) to establish the diagnosis and perform a comprehensive review of C. canimorsus meningitis cases to provide summary data on the clinical manifestations, diagnosis, and outcomes of this unusual infection.

METHODS

A systematic review of the peer-reviewed English literature (PubMed, Embase, Ovid Medline) from January 1966 to March 2018 was conducted to identify cases of C. canimorsus meningitis. Data collected included demographics, risk factors, cerebrospinal fluid (CSF) findings, PCR results, treatments, and outcomes. Descriptive statistics are presented as numbers (percentages) and medians (ranges).

RESULTS

A total of 37 patients were reviewed with a median age of 63 years (12 days to 83 years) with a male predominance (76%). A relatively low proportion had an immunocompromised state (16% splenectomy and 5% steroid use); the most common risk factor was alcoholism (19%). Fifty-nine percent reported a dog bite (all within ≤ 14 days prior to presentation), while 22% reported a non-bite dog exposure, 3% reported cat bite, and 3% reported both dog and cat exposures; 11% reported no animal contact. CSF parameters included a median white count of 1024 cells/mm3, 81% had neutrophilic predominance, median protein of 190 mg/dl, and median glucose CSF/serum ratio 0.23. In 54% of cases, blood cultures were positive for C. canimorsus (median, 4 days) and 70% had positive CSF cultures (median, 5 days). PCR established the diagnosis in eight (22%) cases. Antibiotic therapy was given for a median of 15 days (range, 7 to 42 days). Prognosis was overall favorable with only one (3%) death reported and adverse neurologic and/or physical sequelae in 19% of the survivors.

CONCLUSION

C. canimorsus meningitis is a rare but increasingly important clinical entity occurring in patients of all ages, typically after dog exposure. While classically considered an infection among immunocompromised patients, most cases have occurred in previously healthy, immunocompetent persons. Diagnosis may be rapidly established by PCR, and this test should be considered in culture-negative cases with associated exposures. Outcome was generally favorable after a median antibiotic duration of 15 days.

Capnocytophaga canimorsus sepsis in a methotrexate-treated patient with rheumatoid arthritis

Capnocytophaga canimorsus is a gram-negative rod that can be transmitted primarily by dog bites. This life-threatening organism commonly causes sepsis in patients with splenectomy or alcoholism. A 53-year-old rheumatoid arthritis male treated with methotrexate (MTX) for 5 years was admitted for a 4-day history of fever and dyspnea. He had been bitten on a finger by the family dog 4 days before onset. Laboratory tests revealed pancytopenia, acute renal failure, and evidence of disseminated intravascular coagulation, and he subsequently developed acute respiratory distress syndrome. Furthermore, blood cultures grew gram-negative bacilli and despite intensive treatment, he died 5 days after admission. Later, C. canimorsus was identified from his culture samples using a species-specific polymerase chain reaction. C. canimorsus infections should be considered in the differential diagnosis of sepsis for immunocompromised hosts following animal bites.