Unique Presentation of a Ubiquitous Organism: Capnocytophaga canimorsus Meningitis With Pneumocephalus.

Capnocytophaga canimorsus is a bacterium commonly found in the oral cavities of cats and dogs. Infections are particularly common in immunocompromised patients who have been exposed to bites or come in contact with saliva from these animals. The manifestations of infection include bacteremia, fever, and, rarely, meningitis. Diagnosis is challenging given the bacteria has slow growth on culture media. The organism is susceptible to beta-lactam antibiotics, with higher-generation cephalosporins recommended for treating meningitis. We present a case of a 74-year-old woman with altered mental status and no signs of immunosuppression. She was diagnosed with meningitis caused by Capnocytophaga, with an intriguing finding of pneumocephalus, which is a rare occurrence as per literature review.

Capnocytophaga canimorsus Meningitis Complicated by Septic Shock: The Use of Extracorporeal Blood Purification Techniques.

Capnocytophaga canimorsus is a Gram-negative bacterium, commonly found as a commensal germ in the oral cavity of dogs and cats. It is an opportunistic pathogen, but, in specific situations, it can cause very severe diseases, including arthritis, pleuritis, endocarditis, sepsis, and, in extremely rare cases, meningoencephalitis. The predisposing situations include immunosuppression, liver cirrhosis, splenectomy, hemochromatosis, beta thalassemia major (Cooley's anemia), and alcohol abuse. In this report, we describe the case of a 48-year-old male patient, with a medical history of several predisposing conditions, who developed a severe case of meningoencephalitis caused by C. canimorsus, following a dog bite on his hand. The patient was successfully treated for his meningitis, but subsequently he developed a hospital-acquired septic shock from Acinetobacter baumannii, which was treated with targeted antibiotic therapy and sequential extracorporeal blood purification therapies using Oxiris™ and Toraymyxin™ hemofilters.

Sudden Vision Loss as the First Sign of Sepsis-Bilateral Endogenous Endophthalmitis of Uncommon Capnocytophaga canimorsus Etiology.

We present a case of bilateral endogenous endophthalmitis with an extremely rare etiology of Capnocytophaga canimorsus. A 42-year-old asplenic patient with bilateral deterioration of visual acuity presented to the Emergency Department. The sudden deterioration of visual acuity, which prompted the patient to visit the ophthalmologist, was the first sign of the onset of sepsis. The physicians' attention, in addition to poor visual acuity and intense inflammation on ophthalmologic examination, was drawn to the reported flu-like symptoms. They were accompanied by high C-reactive protein results and abnormalities in echocardiography. A blood culture isolated the bacterium Capnocytophaga canimorsus. Immunocompromised patients are particularly susceptible to C. canimorsus infection. Endophthalmitis of this etiology has a very aggressive course, both ophthalmic and systemic. Therefore, quick diagnosis and initiation of adequate therapy are crucial.

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.

Historique: Le Capnocytophaga canimorsus est un organisme zoonotique à Gram négatif qui a le potentiel de causer une infection humaine dévastatrice. Par le passé, le traitement aux bêta-lactamines, y compris la pénicilline et la ceftriaxone, était efficace. Méthodologie: L'autrice décrit un cas compliqué de méningite à C. canimorsus chez une femme de 70 ans après une plaie punctiforme superficielle causée par la morsure de son chien. Résultats: Ce cas a été compliqué par des convulsions après un traitement à la ceftriaxone. C'est également le premier cas déclaré de méningite à C. canimorsus associée à une maladie de moyamoya et une dysplasie fibromusculaire. Conclusions: Les médecins devraient être au courant du risque de C. canimorsus résistant à la ceftriaxone et du faible seuil pour élargir la couverture antimicrobienne en l'absence d'amélioration clinique. Les auteurs soulèvent également la possibilité d'association entre les vasculopathies et des infections inhabituelles comme le C. canimorsus.

Infective Endocarditis by Capnocytophaga Species-A Narrative Review.

Bacteria belonging to the genus Capnocytophaga are thin, capnophilic, Gram-negative bacilli with tapered ends that include nine species that are isolated from the mouth of humans and animals and, from a phylogenetical perspective, they belong to the family Flavobacteriaceae. Two more species, namely C. endodontalis and C. stomatis have been recovered from a periapical abscess and human and animal infections, respectively. Capnocytophaga spp. can cause serious and potentially life-threatening infections in humans, such as bacteremia and meningitis, most commonly in the context of penetrating trauma as a result of contact with animals, especially after animal bites. Other invasive diseases such as osteomyelitis, septic arthritis, and infective endocarditis (IE) may also occur more rarely. The aim of this study was to review all previously described cases of IE by Capnocytophaga spp. and provide information about the epidemiology, microbiology, antimicrobial susceptibility, clinical characteristics, treatment, and outcomes of this infection. A narrative review based on a search in PubMed, the Cochrane Library, and Scopus was performed. Studies published until 11 September 2023 providing relevant data for IE caused by Capnocytophaga spp. in humans were included. A total of 31 studies containing data from 31 patients were included. A history of dog bites was present in 10 out of 26 patients (38.5%). A prosthetic valve was present in 3 patients (9.7%). The most commonly infected valve was the aortic valve, followed by the tricuspid valve. Fever, embolic phenomena, paravalvular abscess, and sepsis were the most common clinical presentations. Beta-lactams and aminoglycosides were the antimicrobials most commonly used. Surgery was performed in 20 patients (64.5%). Overall mortality reached 16.1%.

Bacterial peritonitis secondary to Capnocytophaga canimorsus

We present the case of a patient with liver cirrhosis and several previous episodes of ascitic decompensation, who was admitted for bacterial peritonitis secondary to Capnocytophaga canimorsus infection. The initial clinical presentation, diagnosis, treatment and resolution are described. This is the first case described of peritonitis caused by this agent in a patient with similar characteristics. (AU)

Furry, Fomite, and Facultative Anaerobe: A Unique Case of Capnocytophaga canimorsus.

Capnocytophaga canimorsus infection is frequently associated with dog and cat bites or scratches in patients who have risk factors such as immunosuppression, asplenia, and alcohol abuse. However, rare instances of C. canimorsus infection in patients without typical risk factors have been reported. Here, we present such a rare and unusual case of C. canimorsus bacteremia in a patient without animal wounds or risk factors. Chronic sinusitis may have contributed to mucosal disruption and served as an entry point for C. canimorsus. Prompt initiation of antibiotics resulted in rapid resolution of symptoms and clearance of bacteremia.

A Case of Uncomplicated Bacteremia Caused by Capnocytophaga canimorsus in an Immunocompetent Patient.

This report describes uncomplicated bacteremia caused by Capnocytophaga canimorsus in an immunocompetent woman who presented with rigor and fever. She was hemodynamically stable. Two blood samples were immediately cultured because rigor indicated bacteremia. Although her symptoms were relieved, Gram-negative rods grew from blood cultures. She noted that she had been bitten by her dog before the first examination. The bacterium was confirmed as C. canimorsus by gene analysis. Infection with C. canimorsus can be fatal when accompanied by sepsis in elderly or immunocompromised patients. However, this case was considered rare as the patient was 41 years old and immunocompetent.

Purpura fulminans secondary to Capnocytophaga canimorsus bacteraemia following a dog bite: A case report and review of literature.

Introduction: Infection due to Capnocytophaga canimorsus may result in a wide variety of clinical presentations. We present a case of life-threatening Capnocytophaga canimorsus infection with evolution of ecchymosis to purpura fulminans. Case description: We present a case of a 43-year-old male with a history of excessive alcohol consumption who presented with features of sepsis following a dog bite. This was associated with a striking, widespread purpuric rash. A causative pathogen, C. canimorsus was identified through blood culture and 16S RNA sequencing. His initially purpuric rash underwent bullous transformation and was diagnosed clinically as purpura fulminans, confirmed on skin biopsy. He made a full recovery with prompt antimicrobial therapy, initially with co-amoxiclav but escalated to clindamycin and meropenem due to clinical deterioration and concerns of beta-lactamase resistance. Discussion: ß-Lactamase producing Capnocytophaga strains are of increasing concern. This particular concern is reflected in our case as 5 days into treatment with ß-lactamase inhibitor combination therapy the patients clinical condition deteriorated but demonstrably improved on switching to a carbapenem.The development of biopsy proven purpura fulminans in this immunocompetent case is a rare severe manifestation of the previously reported manifestation of disseminated intravascular coagulation (DIC) in Capnocytophaga bacteraemia. The case reported describes characteristics common with other DIC presentations such as the presence of clinical risk factors (history of excessive alcohol consumption) and symmetrical involvement. However, an unusual feature in that initial purpuric lesions were followed by the development of a bullous appearance and peripheral necrotic features concerning for purpura fulminans and confirmed with skin biopsy.

Culture-negative Capnocytophaga canimorsus meningitis diagnosed by 16s ribosomal RNA polymerase chain reaction in an immunocompetent veterinarian and a review of the literature.

Capnocytophaga canimorsus is a fastidious, capnophilic and facultative anaerobic Gram-negative rod found commonly in the oral flora of dogs that may cause zoonotic infections such as cellulitis and eye infections. In immunocompromised patients, it may cause fulminant sepsis. Meningitis due to C. canimorsus is, however, a rare manifestation. This is the first reported case of C. canimorsus meningitis in Australia in an immunocompetent veterinarian diagnosed by 16s ribosomal RNA polymerase chain reaction.

Bobo-Newton acute myocarditis caused by Capnocytophaga canimorsus: a case report.

Background: Capnocytophaga canimorsus is a Gram-negative bacillus commensal of the oral cavities of dogs and cats that can cause human infection after a bite or scratch. Cardiovascular manifestations have included endocarditis, heart failure, acute myocardial infarction, mycotic aortic aneurysm and prosthetic aortitis. Case summary: A 37-year-old male presented septic manifestations, ST-segment alterations on the electrocardiogram and troponin rise, 3 days after a dog bite. N-terminal brain natriuretic peptide was elevated and transthoracic echocardiography revealed mild diffuse left ventricular (LV) hypokinesia. Coronary computed tomography angiography showed normal coronary arteries. Two aerobic blood cultures grew Capnocytophaga canimorsus. On Day 5, cardiovascular magnetic resonance (CMR), showed all diagnostic criteria of acute myocarditis, including focal areas of subepicardial oedema in the LV inferolateral wall, early hyperenhancement, nodular or linear foci of late gadolinium enhancement, increased T2-times and extracellular volume fraction. The outcome was favourable with amoxicillin. Discussion: Four cases of myocardial infarction caused by Capnocytophaga canimorsus had been reported and coronary angiography showed normal coronary arteries in 3 cases. Herein, we report a case of documented acute myocarditis associated with Capnocytophaga canimorsus infection. Myocarditis was demonstrated by comprehensive CMR revealing all established diagnostic criteria. Acute myocarditis should be ruled out in patients with Capnocytophaga canimorsus infection and a clinical presentation of "acute myocardial infarction", especially in those with unobstructed coronary arteries.

The dog, valves' best friend: infective endocarditis due to Capnocytophaga canimorsus-a case report.

Background: Capnocytophaga canimorsus is a Gram-negative bacillus found in the oral microbiota of dogs. It is a very rare cause of endocarditis. We hereby present a case of aortic valve endocarditis due to this microorganism. Case Summary: A 39-year-old male was admitted to hospital with a history of intermittent fever and exertion dyspnoea and showed signs of heart failure on physical examination. Transthoracic and transoesophageal echocardiography confirmed the presence of a vegetation in the non-coronary cusp of the aortic valve, aortic root pseudoaneurysm, and left ventricle-to-right atrium fistula (Gerbode defect). The patient underwent aortic valve replacement with a biological prosthesis. The fistula was closed with a pericardial patch, although a dehiscence of the patch was detected in post-operative echocardiogram. The post-operative period was complicated by acute mediastinitis and cardiac tamponade secondary to a pericardial abscess, requiring emergent surgery. The patient made a good recovery afterwards and was discharged 2 weeks later. Discussion: Capnocytophaga canimorsus is a very rare cause of endocarditis, although it can be very aggressive, with high degree of valve damage, necessity of surgery, and high mortality. It mainly affects young men with no previous structural heart disease. Due to its slow growth, blood cultures can be negative, so other microbiological techniques such as 16S RNA sequencing or matrix-assisted laser desorption/ionization and time-of-flight (MALDI-TOF) can be helpful for diagnosis.

Non-severe Serovar Type E Capnocytophaga canimorsus Infection in a Post-splenectomy Male: A Case Report.

Capnocytophaga canimorsus (CP) causes severe infections in immunocompromised individuals. Three serovars (A, B, and C) are known to be responsible for more than 90% of infections associated with dog bites, although these three constitute only 8% of the serovars carried by dogs. We experienced a post-splenectomy non-severe case of CP withserovar type E, which has never been isolated in Japan. The prognosis of type E CP infections may be better than that of types A, B, and C infections because of the disproportion of serovars between clinical human isolates and dog oral isolates.

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

Capnocytophaga canimorsus, oral inhabitants of dogs and cats is a cause of zoonotic infections. It is transmitted to humans by bites, scratches, licks, or close exposure to these animals. Infections due to Capnocytophaga canimorsus have a wide range of severity and can sometimes be fatal. We report the case of an 89-years-old man who suffered from a sudden swollen native right shoulder. The blood test revealed an inflammatory syndrome and cytologic evaluation of joint aspiration showed an elevated nucleated cells count suspicious of infection. A Gram-negative bacillus grew after 48 h in the arthrocentesis and was identified as Capnocytophaga canimorsus. After 4 days, blood culture also grew Capnocytophaga canimorsus leading to the diagnosis of hematogenous septic arthritis of a non-prosthetic right shoulder. Antimicrobial therapy was empirically started with cefuroxime then switched to doxycycline for seven weeks with good clinical outcomes. It is important to inquire about patients' environment including their proximity to animals as it can lead to zoonotic infections that can be of high severity. Moreover, hygiene rules must be applied when dog scratches or lick wounds occurred to avoid the spread of zoonotic germs. Prophylactic antibiotic therapy should be given for animal bites.

Waterhouse-Friderichsen syndrome following a dog bite in an asplenic patient: case report and review of the literature.

The Waterhouse-Friderichsen syndrome represents a critical condition characterized by a septic shock associated with a disseminated intravascular coagulation causing the plugging of the microvascular network virtually all organs and systems, including the skin, the kidneys, the liver, and adrenal glands; the mortality rate is elevated, and survivors often must undergo multiple limb amputations. Here, we describe the uncommon case of an asplenic patient who developed this syndrome after a superficial wound caused by a dog bite causing an initial infection due to Capnocytophaga canimorsus that is part of the normal oral microbiome of pets. The clinical and pathological findings and the current and future therapeutic options are reviewed and discussed.

Hemoadsorption as part of a multimodal therapy concept to treat Capnocytophaga sepsis with thrombocytopenia and multiple organ failure.

BACKGROUND: Capnocytophaga, a bacteria native to the oral flora of canines, in rare cases can lead to severe infections resulting in septic shock, respiratory tract infection, and multiple organ failure. In case of trauma following animal bites with rapidly progressing clinical courses, also adjunctive therapeutic measures such as extracorporeal blood purification therapies might be beneficial. CASE PRESENTATION: We report on a 68-year-old male who was hospitalized with fever, oliguria and repeated vomiting after suffering a minor bite by his dog. On admission, he was diagnosed with sepsis. In addition, his coagulation status was markedly deranged resulting in the administration of mass transfusions to stabilize his coagulative status. Following detection of Capnocytophaga canimorsus, anti-infective therapy was initiated. In the context of a progressive respiratory deterioration and an increasing vigilance disorder, he had to be intubated. Due to development of renal failure, dialysis was started in conjunction with CytoSorb hemoadsorption therapy to control the hyperinflammatory condition. All of the applied therapeutic measures led to a rapid clinical stabilization, a control of the hyperinflammatory situation, and an improvement in his neurological status. The therapy was well tolerated with no complications encountered. CONCLUSIONS: This case supports the clinical recognition of severe Capnocytophaga infection that can lead to critical conditions even in immunocompetent patients. Combined broad spectrum antibiotic therapy, mass transfusions, CRRT, and CytoSorb hemoadsorption therapy resulted in a control of the critical situation. However, further research is needed to fully elucidate the role of hemoadsorption in this rare but life-threatening setting.

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.

Lethal Waterhouse-Friderichsen syndrome caused by Capnocytophaga canimorsus in an asplenic patient.

BACKGROUND: Capnocytophaga canimorsus, a Gram-negative rod, belongs to the Flavobacteriaceae family and colonizes the oropharynx of dogs and cats. Infections with C. canimorsus are rare and can induce a systemic infection with a severe course of the disease. So far, only five case reports of C. canimorsus infections associated with Waterhouse-Friderichsen Syndrome (WFS) have been reported with only two of the patients having a history of splenectomy. CASE PRESENTATION: Here, we report a fatal case of WFS due to C. canimorsus bacteremia and mycetal superinfection in a 61-year-old female asplenic patient. Despite extensive therapy including mechanical ventilation, antibiotic coverage with meropenem, systemic corticosteroids medication, vasopressor therapy, continuous renal replacement therapy, therapeutic plasma exchange, multiple transfusions of blood products and implantation of a veno-arterial extracorporeal membrane oxygenation the patient died 10 days after a dog bite. The autopsy showed bilateral hemorrhagic necrosis of the adrenal cortex and septic embolism to heart, kidneys, and liver. Diagnosis of C. canimorsus was prolonged due to the fastidious growth of the bacteria. CONCLUSIONS: The occurrence of a severe sepsis after dog bite should always urge the attending physician to consider C. canimorsus as the disease-causing pathogen. A therapeutic regimen covering C. canimorsus such as aminopenicillins or carbapenems should be chosen. However, despite maximum therapy, the prognosis of C. canimorsus-induced septic shock remains very poor. Asplenic or otherwise immunocompromised patients are at higher risk for a severe course of disease and should avoid exposure to dogs and cats and consider antibiotic prophylaxis after animal bite.