Capnocytophaga canimorsus, a rare cause of bacterial meningitis

The Great pretender: the first case of septic shock due to Capnocytophaga canimorsus in Sardinia. A Case report and review of the literature

Capnocytophaga canimorsus (C. canimorsus) is an emerging pathogen in critical care. C. canimorsus is a Gram-negative bacillus, commonly isolated as a commensal microorganism of the oral flora of healthy dogs and cats. A 63-year-old woman came to the emergency department with fever, chills, and malaise 2 days after a minor dog bite. After admission to the medicine ward, she developed respiratory failure and livedo reticularis. In the intensive care unit (ICU), she presented full-blown septic shock with thrombocytopenia, coagulopathy, severe acute kidney injury, and liver injury. We describe the first case of septic shock with Multiple Organ Dysfunction Syndrome related to Capnocytophaga canimorsus infection in Sardinia and its treatment in a tertiary hospital ICU. We also review recent literature on the relevance of C. canimorsus in human disease and critical illness.

Meningitis caused by Capnocytophaga canimorsus in a COVID-19 patient: a rare complication of dog bites

Capnocytophaga canimorsus is a gram-negative rod that is part of the commensal microbiota of dogs' and cats' mouths. In this case, we report an 85-year-old man with COVID-19 who had his right arm bitten by a dog. His symptoms were impaired consciousness, agitation and aggressive behavior. Physical examination revealed neck stiffness and Brudzinski's sign. The cerebrospinal fluid culture was compatible with Capnocytophaga canimorsus. He required intensive care and received a 14-day prescription of meropenem. After 40 days of hospitalization, the patient was fully recovered and was discharged. This case highlights the importance of physician and microbiologist be awareness of this disease, mainly in patients with neurological symptoms after a dog or cat bite.

Rare case of Capnocytophaga canimorsus meningitis in a man without risk factors

Capnocytophaga canimorsus meningitis is an uncommon but potentially serious cause of meningitis, which is considered particularly rare in healthy and immunocompetent individuals. We present a case of C. canimorsus meningitis in a young, immunocompetent patient which was acquired following a dog bite. We review the literature and propose that underdiagnosis of this condition is likely. To avoid misdiagnosis, and thus improper management, clinicians should ensure that they identify animal exposure in all meningitic patients, and adopt a higher clinical suspicion in the absence of classical risk factors.

Capnocytophaga canimorsus meningitis diagnosed using next- generation sequencing of microbial cell-free DNA

Capnocytophaga canimorsus meningitis is frequently caused by exposure to dog or cat bites and occurs more commonly in immunocompromised individuals. CSF analysis is the first step in diagnosis; however, in situations where CSF cultures turn negative, molecular techniques such as 16S rRNA gene amplification followed by polymerase chain reaction (PCR) product sequencing have shown promise. Next generation sequencing of cell free DNA (NGS cfDNA) can assist in identifying the causative agent in a quick and accurate manner. We present a rare case of C. canimorsus meningitis in an immunocompetent host that highlights the utility of NGS cfDNA in timely diagnosis after exhausting all other available diagnostic techniques.

Capnocytophaga canimorsus - a potent pathogen in immunocompetent humans - systematic review and retrospective observational study of case reports

Purpose: Severe and fatal Capnocytophaga canimorsus infection has been described in immunocompromised patients. Data of C. canimorsus infection in immunocompetent and risk factors of severe courses are missing. Our aims were to describe the epidemiology of C. canimorsus infection and to identify potential risk factors of sepsis and fatal outcome.Methods: Observational study and systematic review of all cases reported in immunocompetent subjects between 2002 and 2019.Results: A total of 128 cases of C. canimorsus infection in immunocompetent individuals were reported. Male gender comprised 74.2%, the median age was 58 years and 47.7% were admitted with sepsis. Case-fatality rate was 29.7% and especially high in septic patients (55.7%). Transmission by bite (OR = 2.37, 95% CI: 1.05-6.52) and incubation time ≤3 d (OR = 7.98; 95% CI: 2.33-27.34) were identified as risk factors of sepsis on admission, and early wound cleansing as protective (OR = 0.42; 95% CI: 0.14-0.96). Sepsis (OR = 23.67; 95% CI: 2.85-197.89) and septic shock (OR = 45.50; 95% CI: 3.08-676.55) were risk factors of fatal outcome, whereas early wound cleansing (OR = 0.05; 95% CI: 0.01-0.72), initial penicillin therapy with beta-lactamase inhibitors (OR = 0.48; 95% CI: 0.16-0.92) and surgical removal of infectious focus (OR = 0.38; 95% CI: 0.06-0.95) were protective factors.Conclusions: Immunocompetent patients with C. canimorsus infection frequently develop sepsis. A shorter incubation period in cases of sepsis might be related to higher infectious dose. Fatal outcome may be prevented by early wound cleansing, initial use of penicillins in combination with beta-lactamase inhibitors and surgical removal of an infectious focus.