Capnocytophaga canimorsus infections in human: review of the literature and cases report

Updated Recommendations on the Prevention and Treatment of Infections in Children With Asplenia/Hyposplenism

Children with congenital or acquired asplenia or hyposplenism have an increased risk for severe and even life-threatening infections mainly due to encapsulated bacteria. Current practice focuses on preventing severe infections with timely administration of vaccinations, antibacterial prophylaxis when indicated, and urgent evaluation and treatment of febrile events. As new vaccines are now available for both children and adults with asplenia/hyposplenism, we present an up-to-date recommendation on the prevention and management of acute infections in children with asplenia/hyposplenism.

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.

Restoring vision after cat bite: a case report on successful diagnostic and therapeutic regimen for Capnocytophaga endophthalmitis

BACKGROUND

Capnocytophaga is a bacterium frequently found in the oral flora of dogs and cats (e.g. Capnocytophaga canimorsus) and humans (e.g. Capnocytophaga gingivalis). Among Capnocytophaga related ocular infections, fulminant endophthalmitis is a rare but sight-threatening clinical manifestation.

CASE PRESENTATION

A 35-year-old previously healthy patient presented after a cat bite into the left upper and lower eyelid and nasal part of the conjunctiva of the left eye. At initial consultation, the corrected visual acuity was 0.8 in decimal scale and a detailed clinical examination revealed no evidence of ocular penetration. However, daily follow-up examinations under local therapy revealed a progressive intraocular inflammation, therefore the decision was made to perform a diagnostic vitrectomy with intravitreal and systemic antibiotic treatment. Capnocytophaga felis was detected as the cause of endophthalmitis and the initiated treatment resulted in quick morphological and functional recovery of the left eye. After surgery of secondary cataract, visual acuity improved from hand motion preoperatively to 1.0 postoperatively.

CONCLUSIONS

Early recognition as well as prompt and effective treatment of animal bite associated endophthalmitis is essential for good visual recovery and functional outcome. Furthermore, this case highlights the importance of daily follow-up examinations, even in the absence of signs of ocular penetration and intraocular inflammation, to enable prompt and effective treatment initiation. Given the negative results in bacterial culture, we additionally emphasize the value of sequencing-based microbiological diagnostics in unclear cases.

A fatal septic shock caused by Capnocytophaga gingivalis potentially associated with COVID-19: A case report

Background

Capnocytophaga spp. is associated with fulminant sepsis, particularly in those with immunosuppression. We here report a rare case of fatal fulminant septic shock caused by C. gingivalis, concurrent with COVID-19.

Case Presentation

A Japanese woman developed septic shock, which led to her death. Polymerase chain reaction (PCR) testing of the respiratory specimen was positive for SARS-CoV-2, and a CT scan of the chests revealed bilateral ground glass opacities. The blood cultures identified C. gingivalis. The patient had rheumatoid arthritis and was taking prednisone orally. There were no splenic abnormalities shown on the CT scan.

Conclusion

A rare case of fulminant septic shock caused by C. gingivalis, together with COVID-19 was identified. The precise pathogenesis of this combination, together with the best treatment option should be sought by further studies.

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.

A Novel 16S rRNA PCR-Restriction Fragment Length Polymorphism Assay to Accurately Distinguish Zoonotic Capnocytophaga canimorsus and C. cynodegmi

The zoonotic bacteria Capnocytophaga canimorsus and C. cynodegmi, the predominant Capnocytophaga species in the canine oral biota, can cause human local wound infections or lethal sepsis, usually transmitted through dog bites. Molecular surveying of these Capnocytophaga species using conventional 16S rRNA-based PCR is not always accurate due to their high genetic homogeneity. In this study, we isolated Capnocytophaga spp. from the canine oral cavity and identified them using 16S rRNA and phylogenetic analysis. A novel 16S rRNA PCR-restriction fragment length polymorphism (RFLP) method was designed based on our isolates and validated using published C. canimorsus and C. cynodegmi 16S rRNA sequences. The results showed that 51% of dogs carried Capnocytophaga spp. Among these, C. cynodegmi (47/98, 48%) was the predominant isolated species along with one strain of C. canimorsus (1/98, 1%). Alignment analysis of 16S rRNA sequences revealed specific site nucleotide diversity in 23% (11/47) of the C. cynodegmi isolates, which were misidentified as C. canimorsus using previously reported species-specific PCR. Four RFLP types could be classified from all the isolated Capnocytophaga strains. The proposed method demonstrates superior resolution in distinguishing C. cynodegmi (with site-specific polymorphism) from C. canimorsus and especially in distinguishing C. canimorsus from other Capnocytophaga species. After in silico validation, this method was revealed to have an overall detection accuracy of 84%; notably, accuracy reached 100% in C. canimorsus strains isolated from human patients. Overall, the proposed method is a useful molecular tool for the epidemiological study of Capnocytophaga in small animals and for the rapid diagnosis of human C. canimorsus infections. IMPORTANCE With the increased number of small animal breeding populations, zoonotic infections associated with small animals need to be taken more seriously. Capnocytophaga canimorsus and C. cynodegmi are part of common biota in the mouths of small animals and can cause human infections through bites or scratches. In this study, C. cynodegmi with site-specific 16S rRNA sequence polymorphisms was erroneously identified as C. canimorsus during the investigation of canine Capnocytophaga by conventional PCR. Consequently, the prevalence of C. canimorsus is incorrectly overestimated in epidemiological studies in small animals. We designed a new 16S rRNA PCR-RFLP method to accurately distinguish zoonotic C. canimorsus from C. cynodegmi. After validation against published Capnocytophaga strains, this novel molecular method had high accuracy and could detect 100% of C. canimorsus-strain infections in humans. This novel method can be used for epidemiological studies and the diagnosis of human Capnocytophaga infection following exposure to small animals.

A classic case of Capnocytophaga induced septic shock with multi-organ failure after a dog bite in an asplenic patient

We hereby report a case of a 40-year-old male with a recent dog bite, a past history of immune thrombocytopenic purpura (ITP) and therapeutic splenectomy. He presented to the hospital with abdominal pain and shortness of breath, which progressed to sepsis and disseminated intravascular coagulation (DIC). Based on clinical presentation, Capnocytophaga-induced sepsis was suspected, and the diagnosis was confirmed through blood culture. Upon confirmation of the diagnosis, the patient was started on IV ampicillin/sulbactam which improved his condition and led to complete recovery without any long-term effects. Capnocytophaga is a genus of Gram-negative bacteria that are commensal to the oral cavity of common household pets such as dogs and cats. This case highlights the importance of considering Capnocytophaga as a potential pathogen in asplenic patients with recent pet-bites and emphasizes how early recognition and intervention can significantly improve outcomes in these critically-ill patients. It also warrants the need for healthcare providers to consider Capnocytophaga infections from minor pet-bites as a differential diagnosis in immunocompromised as well as immunocompetent individuals.

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.

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.

Capnocytophaga aortitis: A dog's gift to its owner

We present a case of Capnocytophaga aortitis in an 82-year-old male with fever, weakness, confusion, and back pain. Diagnosis was established following a ruptured abdominal aortic aneurysm and subsequent blood culture growth of Capnocytophaga species. He was treated with endovascular aortic repair in addition to a six-week course of ceftriaxone followed by long-term antibiotic suppression with amoxicillin-clavulanate. Capnocytophaga aortitis is exceedingly rare and poorly described in current literature.

Lesions caused by human and domestic and wild animal bites

Animal bites are a common problem in the emergency room. There are many reports of isolated cases (mainly of domestic mammals); however, texts with more comprehensive and general guidance on these kinds of bite injuries are necessary, including those caused by wild mammals, reptiles, and even fish. This review aims to update knowledge on this problem, which includes human and domestic and wild animal bites. Health teams in emergency care centers should be aware of the initial and late measures required to control this problem.

The potential for the double risk of rabies and antimicrobial resistance in a high rabies endemic setting: detection of antibiotic resistance in bacterial isolates from infected dog bite wounds in Uganda

BACKGROUND

Post-exposure treatment for dog bites in humans aims at alleviating the risk of rabies and promoting wound healing. Wound healing may be complicated by bacteria. This study identified the different bacteria and their antibiotic susceptibilities in infected dog bite wounds (DBWs) in Uganda.

METHODS

A cross-sectional study was conducted among 376 dog bite patients. Wound swabs from patients with infected DBWs were collected and inoculated into recommended media. They were cultured for both aerobic and anaerobic bacteria. All isolated bacteria were identified based on colony characteristics, gram stain, and standard biochemical tests. Molecular identification was performed for strains that were resistant to three or more antibiotics. Antibiotic susceptibility testing was conducted using the disc diffusion method following the modified Kirby-Bauer method. The data were analysed using Stata version 15 software.

RESULTS

Approximately half of the patients (52.9%, 199/376) presented with infected wounds. Majority of the swabs (84.4%, 168/199) were culture positive, and yielded a total of 768 isolates where about half (52.9%, 406/768) were gram positive bacteria, and about two-thirds (64.6%, 496/768) were recovered from category II wounds. Among the gram positive bacteria, 339 (83.5%) were aerobes where Staphylococcus aureus (103, 30.4%), Coagulase-negative staphylococci (68, 20.1%), and Corynebacterium spp (33, 9.7%) had the highest prevalence. For the 362 Gram negative isolates, 217 (59.9%) were aerobes and the commonest isolates were P. maltocida (64, 29.5%), Capnocytophaga canimorsus (36, 16.6%) and P. canis (26, 12.0%). Gram-positive isolates were resistant to metronidazole (93.6%), oxacillin (68.5%), ceftriaxone (14.6%) and amoxicillin/clavulanic acid (14.0%). Gram negative isolates were resistant to metronidazole (100%), ampicillin (30.7%), oxacillin (29.3%), and doxycycline (22.9%). Multidrug resistance was in 105 (29.0%) and 121/406 (29.8%) of the gram-negative and gram-positive isolates, respectively. All gram-positive isolates were susceptible to vancomycin and ciprofloxacin.

CONCLUSIONS

Infection rates of DBWs in Uganda are high and the dominant bacterial isolates are Staphylococcus aureus, Pasteurella spps, and Capnocytophaga canimorsus. Multidrug resistance to commonly used antibiotics is high. The recommendation in the Uganda Clinical Guidelines to use metronidazole in the management of DBWs should be reviewed. DBWs should be enlisted for routine antimicrobial resistance surveillance and rational use of antimicrobial agents should be promoted.

The Curious Case of Lip Tongue Fusion: A Consequence of Suboptimal Oral Care

Oral care is an often difficult and an unappreciated part of hospital life. Patients who are unable to provide their own care rely on assistance from hospital personnel. Most sequelae from suboptimal oral care often present over months if not years, in the form of dental caries and periodontal disease. We present an exception, where a 66-year-old patient who experienced widespread ulceration and necrosis from Capnocytophaga-related sepsis received suboptimal oral care, resulting in their tongue being fused to their lip. This was later divided by the oral and maxillofacial team resulting in restoration of full function. Future cases can be avoided in patients with similar symptoms, such as Stevens-Johnson syndrome or erythema multiforme, if rigorous oral care can be provided.

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.

Analysis on Microbial Profiles & Components of Bile in Patients with Recurrent CBD Stones after Endoscopic CBD Stone Removal: A Preliminary Study

Background/Aim: Common bile duct (CBD) stone recurrence after endoscopic treatment is a major concern as a late complication. Biliary bacterial factors and biochemical factors determine the path of gallstone formation. The aim of this preliminary study was to investigate the microbial profile and components of bile in patients with and without recurrent CBD stones after endoscopic CBD stone removal. Methods: Among patients who had undergone an initial endoscopic procedure for the removal of CBD stones and were followed up for >2 years, 11 patients who experienced at least two CBD stone recurrences, six months after endoscopic retrograde cholangiopancreatography (ERCP), were categorized into the recurrence group. Nine patients without CBD recurrence events were matched. Results: Polymicrobial infections are generally seen in all patients who have biliary sphincteroplasty. Microbial richness, measured by the numbers of operational taxonomic units (OTUs), was reduced in the recurrence group. The microbial evenness was also significantly lower than in the non-recurrence group. The overall microbial communities in the recurrence group deviated from the non-recurrence group. Infection with bacteria exhibiting β-glucuronidase activity was more frequent in the recurrence group, but there was no statistical significance. In an analysis of the bile components, the bile acid concentration was higher in the non-recurrence group than in the recurrence group. However, the other metabolites were not significantly different. Conclusions: Microbiota dysbiosis and altered bacterial community assembly in bile duct and decreased bile acid in bile juice were associated with recurrence of bile duct stone.

An Infected Arterial Aneurysm and a Dog Bite: Think at Capnocytophaga canimorsus!

We describe the fourth cases of arterial aneurysm consecutive to Capnocytophaga canimorsus infection in a 77-year-old man. The infection occurred after a dog bite. He presented fever. The thoracic-abdominal computed tomography angiography revealed aneurysms on the abdominal aorta, left common femoral artery, and left popliteal artery. The diagnosis was performed by a blood culture positive for Capnocytophaga canimorsus. The outcome was favorable with surgery and antibiotic therapy.

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 gingivalis Bacteremia After Upper Gastrointestinal Bleeding in Immunocompromised Patient

Odontogenic bacteremia, most commonly involving gram-positive oral flora, can result from daily self-care practices or professional dental procedures. Though usually transient and quickly cleared by the immune system, the presence of periodontal disease increases the frequency of exposure and risk of persistence of oral-systemic infections. Comorbidities such as asplenia, alcoholism, and immunocompromise increase the risk of complications of hematogenous spread and severe systemic illness. Capnocytophaga is a genus of anaerobic fastidious gram-negative bacilli, which is a common member of human oral flora, and its density is proportional to mass of dental plaques and periodontal diseases. Capnocytophaga spp that colonize humans are less virulent and are uncommon causes of bacteremia when compared with the Capnocytophaga typical of canines. C gingivalis has been rarely reported as a cause of disease in immunocompromised or immunocompetent hosts. In this article, we present a case of an immunocompromised 70-year-old man with poor oral hygiene, on methotrexate and prednisone for rheumatoid arthritis and sarcoidosis, who was admitted for chronic obstructive pulmonary disease exacerbation and developed C gingivalis bacteremia and septic shock after an episode of upper gastrointestinal bleeding. Poor oral hygiene in our patient is believed to have increased his risk as an immunocompromised patient to developing C gingivalis bacteremia. This case highlights the importance of oral care in immunocompromised patients especially while hospitalized, and those about to receive transplant, chemotherapy, or on immune modulators.

The Characteristics of Capnocytophaga Infection: 10 Years of Experience

Background

Capnocytopha ga is a gram-negative, facultative anaerobe. Human infection is rare but can lead to devastating outcomes. Capnocytophaga canimorsus can cause sepsis following an animal bite, whereas human-oral-associated Capnocytophaga infections were reported in immunocompromised patients. Current data on these infections are not robust. Our goal is to provide a contemporary description of a unique characteristic of Capnocytophaga infections.

Methods

We performed a retrospective review of all patients with Capnocytophaga infection from January 2010 to August 2020 at 3 main hospitals of Mayo Clinic in Rochester, Minnesota; Scottsdale, Arizona; and Jacksonville, Florida. We collected baseline demographic data, clinical characteristics, microbiological data, and outcomes of C. canimorsus and human-oral-associated Capnocytophaga infection.

Results

Among 82 patients with Capnocytophaga infection, 46 patients (56.0%) had bacteremia. The most common species identified in this group was C. sputigena (57.9%), followed by C. canimorsus (34.8%). Patients with human-oral-associated Capnocytophaga bacteremia were often immunocompromised, presented with neutropenic fever, and had worse 6-month all-cause mortality compared to C. canimorsus bacteremia (36.4% vs 6.2%, P = .03). They also had a higher β-lactamase production rate (36.4% vs 0.0%, P = .02). Among patients without bacteremia, the main clinical syndrome was polymicrobial head and neck infections (47.2%).

Conclusions

Human-oral-associated Capnocytophaga bacteremia occurs primarily in immunocompromised patients, particularly those with hematologic malignancy. In contrast, C. canimorsus bacteremia is more likely to present with community-onset infection related to zoonotic exposure. Human-oral-associated Capnocytophaga infection without bacteremia is frequently isolated in polymicrobial infection; this phenomenon's significance is yet to be fully understood.

Case report of Capnocytophaga canimorsus septicemia with infective endocarditis in a hemodialysis patient: A not widely known dog pathogen

Keeping pets as a companion is a global phenomenon. This relationship, however, is not entirely free of risk as some diseases can be transmitted to human beings. It is important to emphasize safety among pet owners, particularly in people with chronic illness as they may have increased vulnerability to infection which could arise from an intimate relationship. We report an uncommon etiology of sepsis complicated with infective endocarditis in a 63-year old dog-owner who was on hemodialysis. To the best of our knowledge, this is the first case of Capnocytophaga canimorsus infective endocarditis (IE) ever reported in a patient undergoing hemodialysis.

Infectious Complications of Bite Injuries

Animal and human bite injuries are a public health burden. Dog bites outnumber cat bites, but cat bites pose the greatest risk for infection. Skin and soft tissue infections are the most frequent infectious manifestations resulting from bite injury, although invasive infection may occur through direct inoculation or dissemination through the bloodstream. Although contemporary, well-designed trials are needed to inform clinical practice, preemptive antibiotic therapy after a bite injury is warranted for injuries posing high risk for infection and for patients at risk of developing severe infection; antibiotics should target aerobic and anaerobic microbes that comprise the oral and skin flora.

CAPNOCYTOPHAGA CANIMORSUS ENDOPHTHALMITIS AFTER CATARACT SURGERY LINKED TO SALIVARY DOG-TO-HUMAN TRANSMISSION

PURPOSE

To describe a case of acute postoperative bacterial endophthalmitis because of Capnocytophaga canimorsus after cataract surgery, with probable contamination through salivary droplets of dog two days after the procedure.

METHODS

An 83-year-old woman who underwent uncomplicated cataract extraction with intraocular lens implantation, presented 12 days later with acute pain, redness, and vision loss in her left eye. Visual acuity was hand motion and clinical findings suggested the diagnosis of acute postoperative endophthalmitis. The patient underwent diagnostic vitrectomy, intravitreal ceftazidime/vancomycin injection and received oral moxifloxacin (400 mg/day). Two days later, she underwent complete pars-plana vitrectomy because of the absence of clinical improvement. Vitreous samples showed gram-negative bacterium on direct examination but cultures remained sterile, which prompted the realization of a broad-range bacterial polymerase chain reaction analysis.

RESULTS

Polymerase chain reaction on the vitreous sample detected C. canimorsus, a fastidious gram-negative bacterium of the oral canine flora. When asked for recent contact with dogs, the patient reported having proceeded to an intensive tooth care session for her dog at postoperative Day 2. Intravenous ceftriaxone (2 g/day) was added to the treatment. Anterior and posterior segment inflammation slowly resolved, and final visual acuity was 20/160.

CONCLUSION

Although very rare, this complication suggests that patients undergoing ocular surgery should avoid contact with salivary secretions of pets during the early postoperative period. Diagnostic broad-range bacterial polymerase chain reaction is useful to detect unconventional or slow-growing agents in vitreous samples.

Capnocytophaga canimorsus blebitis: case report and review of literature

Background

Capnocytophaga canimorsus is a facultative anaerobic, slow-growing, capnophilic, Gram-negative bacillus, that is commonly found in the microflora of canine and feline oral cavities. Capnocytophaga infections are an emerging zoonotic disease that can cause fatal systemic infections in immunocompromised individuals. Localized ocular Capnocytophaga infections, including keratitis, blepharitis, and endophthalmitis, can lead to severe eye threatening situations. To our knowledge, there is currently no documented case of Capnocytophaga canimorsus blebitis with bleb perforation after trabeculectomy.

Case presentation

Our case report and literature review features a novel case of Capnocytophaga blebitis that occurred after trabeculectomy, associated with close dog contact (i.e. face licking). The patient had underwent trabeculectomy 10 years prior and presented with conjunctival injection, perforated bleb, and hypotony. Overall, patient was medically treated subconjunctival vancomycin, gentamicin and moxifloxacin drops. Trabeculectomy revision was performed with good visual outcome. Bacterial cultures grew Capnocytophaga canimorsus.

Conclusions

We discuss the strategies for diagnosis, treatment, and common risk factors for ocular Capnocytophaga infections. At-risk patients with ocular infections should be asked about close contact with dogs and cats; and treated promptly with the proper antibiotic regimen.

Overwhelming Sepsis due to Capnocytophaga canimorsus in an Immunocompetent Individual: A Rare Case Study

We report this rare case of fatal fulminant sepsis in a 42-year-old African American female who presented with a three-day history of generalized pain and an evolving rash all over her body. On presentation, the patient was tachycardic, borderline hypotensive, and febrile. Physical examination was significant for diffuse petechiae and ecchymoses over the extremities, torso, and the face, especially confluent over her thighs and lower abdomen. She was admitted to the ICU, and initial investigations revealed a normal leukocyte count and hemoglobin but severe thrombocytopenia, elevated creatinine, blood urea nitrogen (BUN), bilirubin, transaminases, and an elevated INR. She also had a high anion gap metabolic acidosis with elevated lactate. Chest and abdomen CT findings were nonspecific, demonstrating fluid surrounding both kidneys, a moderate amount of fluid in the pelvis, and alveolar opacities at the bases of both lungs. Initial working diagnoses were a septic shock, thrombotic thrombocytopenic purpura (TTP), and vasculitis. She was initiated on broad-spectrum antibiotic coverage with vancomycin, piperacillin/tazobactam, and doxycycline pending culture reports. After a few hours, she became progressively hypothermic, developed disseminated intravascular coagulation (DIC) and hemodynamic instability, and was intubated due to acute hypoxic and hypercapnic respiratory failure. She progressively worsened hemodynamically with multi-organ dysfunction, and ultimately was pronounced dead roughly 18 hours after initial presentation. Blood cultures grew a Gram-negative organism, initially reported as Shewanella putrefaciens, but subsequently confirmed as Capnocytophaga canimorsus.

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.

Unexpected pathogen presenting with purulent meningitis

Herein we report a case of a 67-year-old man with chronic lymphocytic leukaemia who developed acute onset of fever and altered mental status while receiving ibrutinib therapy. He was eventually found to have Capnocytophaga canimorsus meningitis. Timely diagnosis and appropriate antimicrobial therapy was associated with a favourable outcome. We describe challenges associated with appropriate identification of, and briefly review infections caused by Capnocytophaga sp. To our knowledge, this is the first case of invasive C. canimorsus infection in the setting of ibrutinib therapy, and adds to the growing list of serious infections that have been associated with this agent.

Hemophagocytic syndrome with severe sepsis caused by Capnocytophaga canimorsus

Capnocytophaga canimorsus, commonly transmitted by dog bites, can cause severe sepsis, and the mortality rate is very high. We experienced a case of hemophagocytic lymphohistiocytosis (HLH) complicated by severe sepsis caused by C. canimorsus. A 58-year-old man with no remarkable medical history was admitted to another hospital with fever and mild consciousness disorder developed 3 days after being bitten by his dog. The next day, the patient developed disseminated intravascular coagulation and shock and was transferred to our emergency medical center. Blood tests showed hyperferritinemia and cytopenia, and bone marrow aspiration was performed. As a result, we diagnosed severe sepsis and HLH. Once antibiotic and steroid therapy was started, the patient's infection and cytopenia improved. Unfortunately, the patient's fingers and toes required amputation, but his life was saved, and he was discharged from hospital. Because HLH may be hidden in such cases, it may be necessary to measure serum ferritin and perform bone marrow aspiration if hyperferritinemia is suspected.

Post-splenectomy Sepsis: A Review of the Literature

The spleen is an intraperitoneal organ that performs vital hematological and immunological functions. It maintains both innate and adaptive immunity and protects the body from microbial infections. The removal of the spleen as a treatment method was initiated from the early 1500s for traumatic injuries, even before the physiology of spleen was properly understood. Splenectomy has therapeutic effects in many conditions such as sickle cell anemia, thalassemia, idiopathic thrombocytopenic purpura (ITP), Hodgkin’s disease, and lymphoma. However, it increases the risk of infections and, in some cases, can lead to a case of severe sepsis known as overwhelming post-splenectomy infection (OPSI), which has a very high mortality rate. Encapsulated bacteria form a major proportion of the invading organisms, of which the most common is Streptococcus pneumoniae. OPSI is a medical emergency that requires prompt diagnosis (with blood cultures and sensitivity, blood glucose levels, renal function tests, and electrolyte levels) and management with fluid resuscitation along with immediate administration of empirical antimicrobials. OPSI can be prevented by educating patients, vaccination, and antibiotic prophylaxis. This article summarizes the anatomy and physiology of the spleen and highlights its important functions. It primarily focuses on the pathophysiology of OPSI, its current management, and prevention strategies.

A rare case of purulent meningitis caused by Capnocytophaga canimorsus in the Czech Republic - case report and review of the literature

Background

Invasive infections caused by Capnocytophaga canimorsus are rare. Immunocompromised patients, who report being bitten by or having a close contact with an animal, represent a high-risk group for this infection. There are only few dozens of infections by this bacteria manifesting as purulent meningitis reported worldwide. The reported case is a first reported case of purulent meningitis caused by by Capnocytophaga canimorsus in Czech Republic with only a limited risk factor history.

Case presentation

The patient, a 74 years old man, was referred to the infectious diseases department of a teaching hospital with clear signs of developing purulent meningitis. His anamnestic data did not show any unusual findings. He was treated for compensated diabetes mellitus type II. The blood cultures were negative and the etiological agent did not grow from the cerebrospinal fluid (CSF) on common media. Eventually, it was identified by detecting pan-bacterial DNA and DNA sequencing. Subsequently, the pathogen was confirmed by anaerobic cultivation from CSF. Only after then the patient recalled being bitten by his German shepherd puppy during play. The patient was successfully treated intravenously by ceftriaxone.

Conclusions

Purulent meningitis caused by Capnocytophaga spp. is a rare disease, but it needs to be considered in patients at risk with pre-existing conditions, who report close contact with or being bitten by an animal. It is important to test for this microbe in cases with negative microbiological results for the more common agents.

Molecular identification and diversity analysis of dental bacteria in diabetic and non-diabetic females from Saudi Arabia

Periodontal disease is a chronic infectious disease, which is characterized by the damaged dental hard tissue by lactic acid generated by microorganisms after the fermentation of carbohydrates rich diet. The risk of periodontal disease is known to be higher in diabetic patients. We compared the diversity of five commonly occurring dental bacteria including Porphyromonas gingivalis, Tannerella forsythia, Capnocytophaga ochracea, Prevotella intermedia, and Aggregatibacter actinomycetemcomitans in 14 type-2 diabetic patients and equal numbers of healthy controls. The subgingival samples were collected using sterile paper points. We used 16S rRNA sequence specific primers for PCR-based identification of dental bacteria. Our results showed that A. actinomycetemcomitans was completely absent in control subjects but present in 43% of diabetic patients. C. ochracea was highly prevalent in diabetic patients (100%) as compared to controls (28.5%). The frequency of other three bacterial species was also higher in diabetic patients than control subjects. These findings indicate that dental bacteria are highly prevalent in subgingival pockets of diabetic patients. Therefore, proper monitoring of diabetic patients for dental care is important to prevent bacterial growth and its sequela in risky individuals. Further case-control studies using larger sample size would help in validating the association between oral diseases and diabetes.

Capnocytophaga bacteremia precipitating severe thrombocytopenia and preterm labor in an asplenic host

Capnocytophaga species are gram-negative bacilli that inhabit mammalian oral surfaces and can cause opportunistic infection, especially in asplenic patients. The species Capnocytophaga canimorsus is particularly associated with dog bites and is known to cause endocarditis, meningitis, and sepsis in the general population. In pregnant patients, infections tied to Capnocytophaga species from human flora have been associated with preterm labor, chorioamnionitis, and neonatal septicemia. There is little known about the effects of zoonotically-acquired Capnocytophaga infection in pregnant patients. In this case report, we present a patient with Capnocytophaga bacteremia acquired after a dog bite associated with profound thrombocytopenia and preterm labor. Dog bites are common in the United States, and we present basic recommendations for management of dog bites in pregnant patients in order to avoid morbidity associated with delay in time to antibiotic treatment of infection as described in this case.

Post-splenectomy sepsis: preventative strategies, challenges, and solutions

Removal of the spleen had already been established as a routine technique to treat splenic trauma and other diseases affecting the spleen before the anatomy, physiology, and function of the spleen were known in the mid-twentieth century. It is now widely accepted that the splenectomized individual is at increased risk for infection, in particular, overwhelming post-splenectomy infection (OPSI). OPSI is a syndrome of fulminant sepsis occurring in splenectomized (asplenic) or hyposplenic individuals that is associated with high mortality and morbidity. Poorly opsonized bacteria such as encapsulated bacteria, in particular, Streptococcus pneumoniae, are often implicated in sepsis. The spleen is a reticuloendothelial organ that facilitates opsonization and phagocytosis of pathogens, in addition to cellular maintenance. Splenectomy is associated with an impairment in immunoglobulin production, antibody-mediated clearance, and phagocytosis, leading to an increased risk of infection and sepsis. Early identification of the at-risk patient, early blood cultures prior to antibiotic administration, urgent blood smears and fast pathogen-detection tests, and sepsis bundles should be utilized in these patients. Prompt management and aggressive treatment can alter the course of disease in the at-risk splenectomized patient. Overwhelming post-splenectomy infection can be prevented through vaccination, chemoprophylaxis, and patient education. This article evaluates post-splenectomy sepsis by summarizing the anatomy and function of the spleen, physiological changes after splenectomy that predispose the splenectomized patient to infection, and current management and prevention strategies.

A case of Capnocytophaga canimorsus meningitis and bacteraemia

Capnocytophaga canimorsus is a commonly detectable commensal in the oral flora of dogs and cats, found in 25.5% and 15%, respectively, by culture and 70% and 55%, respectively, by molecular methods [1]. Formerly known as dysgonic fermenter 2 (DF-2), it was first reported in 1976 as a Gram-negative bacillus causing septicaemia and meningitis following dog bites [2]. It causes a spectrum of clinical syndromes from wound infections to bacteraemia and meningitis, especially in those with hyposplenism and alcoholism. We report a case of C. canimorsus meningitis and bacteraemia, and give a review of the relevant literature.

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.

A dog's dinner: an interesting case presenting as gastroenteritis

We report a case of a 60-year-old Caucasian man with a history of alcohol excess who presented to the emergency department with a 72-hour history of abdominal pain, profuse diarrhoea and vomiting. He was admitted to the intensive care unit (ICU) 12 hours later in extremis with severe sepsis and multiorgan failure. Collateral history from the patient on admission to ICU identified that he had been bitten by a dog 3 days prior to his symptom onset. Provisional microscopy and Gram staining from peripheral blood cultures taken on admission revealed the presence of long, thin Gram-negative bacilli in the anaerobic bottle only. This was later identified as Capnocytophaga canimorsus The patient survived the septic episode and was discharged to level 2 care 9 days later under the care of the renal physicians for ongoing renal dialysis.

First whole genome sequencing of Russian isolate of Capnocytophaga canimorsus, opportunistic pathogen causing lethal sepsis

Capnocytophaga canimorsus is a part of healthy oral flora of dogs and cats. However, when it is transmitted to human subjects via animal bites or scratches, it can cause severe complications like endocarditis or even lethal septic shock, especially in immunocompromised persons. In this study, we performed the first whole-genome sequencing on Illumina HiSeq platform of Russian isolate of C. canimorsus that have caused lethal sepsis in 51-old male from Moscow. We believe that the availability of genomic sequence and annotation for the given strain could be useful for future epidemiological surveillance studies in Russia and other countries.

Why Asplenic Patients Should Not Take Care of the Neighbour's Dog? A Fatal Course of Capnocytophaga canimorsus Sepsis

Capnocytophaga canimorsus (CC) belongs to the family Flavobacteriaceae which physiologically occurs in the natural flora of the oral mucosa of dogs and cats. In patients with a compromised immune system, CC can induce a systemic infection with a fulminant course of disease. Infections with CC are rare, and the diagnosis is often complicated and prolonged. We describe a patient with a medical history of prior splenectomy who presented with an acute sepsis and disseminated intravascular coagulation (DIC) and was initially treated on Waterhouse-Friderichsen syndrome (WFS). After the patient had died despite forced treatment in the intermediate care unit, the differential diagnosis of CC was confirmed by culture of blood smears. Later on, a retrospective third-party anamnesis revealed that the patient had contact to his neighbour's dog a few days before disease onset. In conclusion, patients with CC infection can mimic WFS and therefore must be included in the differential diagnosis, especially in patients with a corresponding medical history of dog or cat bites, scratches, licks, or simple exposure.

Molecular dynamics simulations suggest why the A2058G mutation in 23S RNA results in bacterial resistance against clindamycin

Clindamycin, a lincosamide antibiotic, binds to 23S ribosomal RNA and inhibits protein synthesis. The A2058G mutation in 23S RNA results in bacterial resistance to clindamycin. To understand the influence of this mutation on short-range interactions of clindamycin with 23S RNA, we carried out full-atom molecular dynamics simulations of a ribosome fragment containing clindamycin binding site. We compared the dynamical behavior of this fragment simulated with and without the A2058G mutation. Molecular dynamics simulations suggest that clindamycin in the native ribosomal binding site is more internally flexible than in the A2058G mutant. Only in the native ribosome fragment did we observe intramolecular conformational change of clindamycin around its C7-N1-C10-C11 dihedral. In the mutant, G2058 makes more stable hydrogen bonds with clindamycin hindering its conformational freedom in the ribosome-bound state. Clindamycin binding site is located in the entrance to the tunnel through which the newly synthesized polypeptide leaves the ribosome. We observed that in the native ribosome fragment, clindamycin blocks the passage in the tunnel entrance, whereas in the mutated fragment the aperture is undisturbed due to a different mode of binding of clindamycin in the mutant. Restricted conformational freedom of clindamycin in a position not blocking the tunnel entrance in the A2058G mutant could explain the molecular mechanism of bacterial resistance against clindamycin occurring in this mutant.

Capnocytophaga canimorsus: a rare case of conservatively treated prosthetic valve endocarditis

We describe a rare case of prosthetic valve endocarditis caused by the canine bacterium Capnocytophaga canimorsus in a male aged 73 years. The diagnosis of infective endocarditis was unequivocal, as it blood cultures were positive for C. canimorsus and vegetations were detected on transesophageal echocardiography; the modified Duke criteria were fulfilled. PET-CT showed intense ¹⁸ F-FDG uptake of the prosthetic valve area. The patient was treated with antibiotics alone (no surgery), and is now on life-long suppressive antibiotic therapy. To our knowledge, this is the third reported case of prosthetic valve endocarditis caused by C. canimorsus and the first one to have been treated conservatively.

[A fatal septic shock due to Capnocytophaga canimorsus and review of literature]

INTRODUCTION

Capnocytophaga canimorsus is a Gram-negative bacterium present in normal dogs and cats mouths. It can be responsible for septic shocks after dog or cat bite, especially in asplenic patients.

CASE REPORT

We report here a case of C. canimorsus infection rapidly presenting as a multiple organ dysfonction syndrome in an immunocompetent 54 years old patient, who lives near a dog, without any sign of bite. The evolution was a rapidly fatal fulminant septic shock.

CONCLUSION

Among patients with a septic shock of unknown etiology, fatal evolution due to C. canimorsus should be avoided by systematic use of early antibiotherapy with amoxicilline and clavulanic acid, especially in patients who live near a pet, even if they are immunocompetent.