Unexpected pathogen presenting with purulent 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.

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.

Bilateral acute renal cortical necrosis after a dog bite: case report

Background

Capnocytophaga canimorsus is a Gram-negative capnophilic rod and part of dogs/cats’ normal oral flora. It can be transmitted by bites, scratches, or even by contact of saliva with injured skin. Asplenic patients and patients with alcohol abuse are at particular risk for fulminant C. canimorsus sepsis. However, also immunocompetent patients can have a severe or even fatal infection. This is the first case of a severe C. canimorsus infection in an immunocompromised host complicated by acute renal cortical necrosis with a “reverse rim sign” in contrast-enhanced computed tomography on hospital admission.

Case presentation

We report the case of a 44-year functionally asplenic patient after an allogeneic stem cell transplantation, who presented with septic shock after a minor dog bite injury 4 days prior. Because of abdominal complaints, epigastric pain with local peritonism, and radiological gallbladder wall thickening, an abdominal focus was suspected after the initial work-up. The patient underwent emergent open cholecystectomy, but the clinical suspicion of abdominal infection was not confirmed. Septic shock was further complicated by cardiomyopathy and disseminated intravascular coagulation. As a causative pathogen, C. canimorsus could be isolated. The clinical course was complicated by permanent hemodialysis and extensive acral necrosis requiring amputation of several fingers and both thighs.

Conclusion

We present a severe case of a C. canimorsus infection in a functionally asplenic patient after a minor dog bite. The clinical course was complicated by septic shock, disseminated intravascular coagulation, and the need for multiple amputations. In addition, the rare form of acute renal failure - bilateral acute renal cortical necrosis – was visible as “reverse rim sign” on computed tomography scan. This case is an example of the potential disastrous consequences when omitting pre-emptive antibiotic therapy in wounds inflicted by cats and dogs, particularly in asplenic patients.

Ibrutinib-associated necrotic nasal lesion and pulmonary infiltrates

Herein, we report a case of a 68-year-old woman receiving ibrutinib for chronic lymphocytic leukaemia, who presented with septic shock and a progressive necrotic lesion on her nose. Surgical pathology of the nasal lesion revealed evidence of tissue necrosis, and both tissue and blood culture grew Pseudomonas aeruginosa A diagnosis of ecthyma gangrenosum was made. Additional investigations also led to the discovery of invasive pulmonary aspergillosis. To our knowledge, this is the first case of ecthyma gangrenosum secondary to Pseudomonas sepsis and concurrent invasive pulmonary aspergillosis associated with ibrutinib use.