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

Capnocytophaga canimorsus infections in The Netherlands: a nationwide survey

A retrospective nationwide survey on the occurrence of Capnocytophaga canimorsus and Capnocytopaga cynodegmi infections in The Netherlands over 3 years showed 32 cases, of which 31 were caused by C. canimorsus and one by an unspecified oxidase-positive Capnocytophaga strain. Twenty-eight patients had been diagnosed by blood culture, one by culture from both blood and cerebrospinal fluid (CSF), one by culture from a conjunctival swab, and two patients by 16S rRNA gene amplification by PCR directly from a blood or CSF specimen. The incidence rate was 0.67 infections per million population. Bacteraemia was found in 94% of the cases. The age range of patients was 38-80 years; 72% of them were male. Among 26 patients from whom clinical data were available, splenectomy was not reported, but alcoholism was reported in five. Nine patients (35%) had been admitted to the intensive-care unit, and three patients (13%) died. The mortality rate was much lower than observed in previous studies.

'Biting the hand that feeds': fever and altered sensorium following a dog bite

Capnocytophaga canimorsus infection is the most severe and rapidly progressive bacterial infection transmitted by dog bite and fortunately is very rare. The authors describe a 68-year-old gentleman who presented in an acute confusional state 2 days after having been bitten on the left hand by a dog. Despite immediate broad-spectrum intravenous antibiotics, he developed significant sequelae including disseminated intravascular coagulopathy, microvascular emboli leading to peripheral necrosis, widespread local tissue destruction and septic arthritis. Our case illustrates a life-threatening presentation of infection with C. canimorsus, which is known as 'the dog bite organism'. Early diagnosis and aggressive treatment is key to survival.

Capnocytophaga canimorsis a cause of septicaemia following a dog bite: a case review

Described in this study is the case of a 53-year-old woman who developed a life-threatening infection caused by the bacterium Capnocytophaga canimorsus (C. canimorsus), subsequent to being bitten by a dog. The patient presented to an Emergency Department with a 24-h history of diarrhoea and vomiting with dehydration but within 36 h of presentation developed an overwhelming severe sepsis with septic shock, disseminated intravascular coagulation, acute renal failure, metabolic acidosis and threatened acute respiratory failure requiring urgent intensive care intervention. At subsequent questioning her husband volunteered that she had been bitten on the wrist by the family dog 24h prior to the onset of symptoms; this bite had been extremely minor, requiring no treatment at the time and leaving only a very superficial wound. The causative organism was finally identified two weeks later as C. canimorsus, a common commensal in the oral flora of dogs. C. canimorsus has been reported as a rare cause of severe infection in susceptible individuals; however this case is of particular interest as there were no apparent predisposing factors conferring risk of severe infection. This case also raised significant practice issues for the treating hospital.

Infections of people with complement deficiencies and patients who have undergone splenectomy

The complement system comprises several fluid-phase and membrane-associated proteins. Under physiological conditions, activation of the fluid-phase components of complement is maintained under tight control and complement activation occurs primarily on surfaces recognized as "nonself" in an attempt to minimize damage to bystander host cells. Membrane complement components act to limit complement activation on host cells or to facilitate uptake of antigens or microbes "tagged" with complement fragments. While this review focuses on the role of complement in infectious diseases, work over the past couple of decades has defined several important functions of complement distinct from that of combating infections. Activation of complement in the fluid phase can occur through the classical, lectin, or alternative pathway. Deficiencies of components of the classical pathway lead to the development of autoimmune disorders and predispose individuals to recurrent respiratory infections and infections caused by encapsulated organisms, including Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. While no individual with complete mannan-binding lectin (MBL) deficiency has been identified, low MBL levels have been linked to predisposition to, or severity of, several diseases. It appears that MBL may play an important role in children, who have a relatively immature adaptive immune response. C3 is the point at which all complement pathways converge, and complete deficiency of C3 invariably leads to severe infections, including those caused by meningococci and pneumococci. Deficiencies of the alternative and terminal complement pathways result in an almost exclusive predisposition to invasive meningococcal disease. The spleen plays an important role in antigen processing and the production of antibodies. Splenic macrophages are critical in clearing opsonized encapsulated bacteria (such as pneumococci, meningococci, and Escherichia coli) and intraerythrocytic parasites such as those causing malaria and babesiosis, which explains the fulminant nature of these infections in persons with anatomic or functional asplenia. Paramount to the management of patients with complement deficiencies and asplenia is educating patients about their predisposition to infection and the importance of preventive immunizations and seeking prompt medical attention.

Prevalence of Capnocytophaga canimorsus and Capnocytophaga cynodegmi in dogs and cats determined by using a newly established species-specific PCR

Capnocytophagacanimorsus and Capnocytophagacynodegmi, fastidious gram-negative rods, are commensal microbes thriving in the oral cavities of dogs and cats. C. canimorsus can sometimes cause fatal systemic infections in humans. In the present study, we established a specific PCR which could identify and distinguish C. canimorsus from C. cynodegmi. The prevalence of Capnocytophaga spp. in dogs and cats was determined using this method. C. canimorsus was detected in 74% of dogs and 57% of cats. C. cynodegmi was detected in 86% of dogs and 84% of cats. The prevalence of Capnocytophaga spp. obtained in this study is somewhat higher than those reported previously where bacterial isolation method was used for identification. This is probably due to the fact that the PCR detection is more sensitive compared to bacterial isolation. Our findings suggest the importance of informing people who belong to high-risk groups as well as health care workers on C. canimorsus infection and its potential risk to people particularly to those who are immunocompromised.

Molecular characterization of Capnocytophaga canimorsus and other canine Capnocytophaga spp. and assessment by PCR of their frequencies in dogs

Capnocytophaga canimorsus can be a virulent pathogen, whereas C. cynodegmi is of low virulence. Heterogeneity within these species, their frequency in dogs, and pathogenicity factors are largely unknown. Strains from blood cultures from patients presumptively identified as C. canimorsus (n = 25) and as C. cynodegmi by rrs analysis (n = 4), blood cultures from dogs (n = 8), blood cultures from cats (n = 2), and cultures from swabs from dog mouths (n = 53) were analyzed. PCR-restriction fragment length polymorphism (PCR-RFLP), a species-specific PCR on rpoB, and rrs sequencing were used. All 29 strains from human blood cultures could be grouped into three PCR-RFLP types. One included the C. canimorsus type strain, and the other types were closely related. Two canine strains were C. canimorsus and grouped into the least common RLFP pattern group. Five were C. cynodegmi and clustered with the reference strain. One canine and both feline strains were distinct. Four human strains that presumptively had been identified as C. cynodegmi by RNA gene sequence analysis clustered with the C. canimorsus strains by both PCR-RFLP and the sequence-specific PCR of the rpoB gene. C. canimorsus DNA was present in 73% (range, 61 to 85%) of dogs' mouths, and C. cynodegmi DNA was present in 96% (range, 94 to 100%) of dogs' mouths. As defined by rpoB PCR-RFLP and by PCRs using specific primers, all strains from human blood were C. canimorsus. The sequencing of rrs genes suggested the presence of different gene copies in a few strains, indicating that the method is less appropriate for species identification. Both species are present in the majority of dogs. Additional Capnocytophaga species occur in dogs' and cats' mouths.

Capnocytophaga canimorsus septicaemia in an asplenic patient with systemic lupus erythematosus

Asplenic patients are highly susceptible to infections with encapsulated bacteria such as Capnocytophaga canimorsus, a gram negative bacillus which is a commensal organism in cat and dog saliva. We describe the first case of septic shock due to C canimorsus infection occurring in a 51-year-old woman with functional asplenism related to systemic lupus erythematosus with antiphospholipid antibodies. Because of the potential severity of this infection, physicians have to be aware of its occurrence in lupus patients.

Capnocytophaga canimorsus a novel pathogen for joint arthroplasty

We report the case of a 59-year-old man with Waldenstrom's macroglobulinemia and active alcohol use who presented with bilateral knee pain 5 years after a bilateral staged TKA. Cultures of synovial fluid and periprosthetic tissue specimens from both knees yielded, after prolonged anaerobic incubation, a catalase- and oxidase-positive gram-negative bacillus, which was identified as Capnocytophaga canimorsus by 16S ribosomal RNA PCR analysis. C. canimorsus, an organism that is commonly found in dog and cat saliva, is a rare cause of various infections in immunocompromised and healthy individuals. However, a review of the medical literature indicates C. canimorsus has not been reported previously to cause infection after joint arthroplasty. The patient was immunocompromised by cytotoxic chemotherapy, corticosteroids, and alcohol use. The patient was managed successfully with bilateral two-stage exchange and 6 weeks of intravenous ertapenem therapy. Because of its fastidious and slow-growing characteristics, C. canimorsus may be an unrecognized cause of culture-negative joint arthroplasty infections, especially in cases when dog and cat exposure is evident in the clinical history.

Man's best friend? Infective endocarditis due to Capnocytophaga canimorsus

Infective endocarditis caused by zoonotic microorganisms is an uncommon clinical entity. A 55-year-old man was diagnosed with endocarditis due to Capnocytophaga canimorsus, a commensal bacterium contained in the saliva of dogs, that involved the aortic and tricuspid valves and was complicated by a para-aortic valve abscess and aorta-to-right atrial fistula. The patient was successfully treated with antibiotic therapy and surgical intervention. C canimorsus endocarditis should be considered in patients with culture-negative endocarditis, particularly in immunosuppressed, asplenic or alcoholic individuals who have recently suffered a dog bite or have had close contact with dogs.

Resistance of Capnocytophaga canimorsus to killing by human complement and polymorphonuclear leukocytes

Capnocytophaga canimorsus is a bacterium of the canine oral flora known since 1976 to cause rare but severe septicemia and peripheral gangrene in patients that have been in contact with a dog. It was recently shown that these bacteria do not elicit an inflammatory response (H. Shin, M. Mally, M. Kuhn, C. Paroz, and G. R. Cornelis, J. Infect. Dis. 195:375-386, 2007). Here, we analyze their sensitivity to the innate immune system. Bacteria from the archetype strain Cc5 were highly resistant to killing by complement. There was little membrane attack complex (MAC) deposition in spite of C3b deposition. Cc5 bacteria were as resistant to phagocytosis by human polymorphonuclear leukocytes (PMNs) as Yersinia enterocolitica MRS40, endowed with an antiphagocytic type III secretion system. We isolated Y1C12, a transposon mutant that is hypersensitive to killing by complement via the antibody-dependent classical pathway. The mutation inactivated a putative glycosyltransferase gene, suggesting that the Y1C12 mutant was affected at the level of a capsular polysaccharide or lipopolysaccharide (LPS) structure. Cc5 appeared to have several polysaccharidic structures, one being altered in Y1C12. The structure missing in Y1C12 could be purified by classical LPS purification procedures and labeled by tritiated palmitate, indicating that it is more likely to be an LPS structure than a capsule. Y1C12 bacteria were also more sensitive to phagocytosis by PMNs than wild-type bacteria. In conclusion, a polysaccharide structure, likely an LPS, protects C. canimorsus from deposition of the complement MAC and from efficient phagocytosis by PMNs.

Prevalence of Capnocytophaga canimorsus in dogs and occurrence of potential virulence factors

Capnocytophaga canimorsus is a Gram-negative commensal of dog's mouth causing severe human infections. A strain isolated from a human fatal infection was recently shown to have a sialidase, to inhibit the bactericidal activity of macrophages and to block the release of nitric oxide by LPS-stimulated macrophages. The present study aimed at determining the prevalence of C. canimorsus in dogs and the occurrence of these hypothetical virulence factors. C. canimorsus could be retrieved from the saliva of 61 dogs out of 106 sampled. Like in clinical isolates, all dog strains had a sialidase and 60% blocked the killing of phagocytosed Escherichia coli by macrophages. In contrast, only 6.5% of dog strains blocked the release of nitric oxide by LPS-challenged macrophages, suggesting that this property might contribute to virulence. The comparative analysis of 69 16S rDNA sequences revealed the existence of C. canimorsus strains that could be misdiagnosed.

Community-acquired Capnocytophaga canimorsus meningitis in adults: report of one case with a subacute course and deafness, and literature review

INTRODUCTION

An adult with community-acquired Capnocytophaga canimorsus meningitis presented with a subacute course, deafness, and a predominantly lymphocytic CSF cell count.

METHODS

Eighteen reported cases of C. canimorsus meningitis in adults were analyzed.

RESULTS

In about half the cases, CSF contained less than 1,000 leukocytes/microL or lymphocyte percentages 30%. These figures differ from those usually seen in meningitis caused by the classic meningeal pathogens.

CONCLUSIONS

C. canimorsus should be included among the causes of sporadic lymphocytic meningitis in adults, in particular if the presentation involves deafness.

A patient with bacteraemia and possible endocarditis caused by a recently-discovered genomospecies of Capnocytophaga: Capnocytophaga genomospecies AHN8471: a case report

INTRODUCTION

Capnocytophaga are a genus of bacteria that have been found to be the causative organisms in a range of infections, including serious conditions such as bacteraemia, endocarditis and meningitis. This has been especially true amongst those with serious comorbidities and the immunocompromised populations. Although several species are known to cause human disease, historically, laboratories have often not identified isolates to species level due to the unreliable, laborious techniques needed. With the advent of Polymerase Chain Reaction-Restriction Fragment Length Polymorphism Analysis, identification to species level is now frequently possible and desirable, as it may provide clues as to the source of infection and its treatment.

CASE PRESENTATION

Here we describe a case of bacteraemia and possible endocarditis in a 64-year-old white British man caused by a newly identified genomospecies of Capnocytophaga in a patient subsequently diagnosed with metastatic adenocarcinoma of the oesophagus. The source of the bacteraemia was presumed to be from the patient's own oral flora.

CONCLUSION

Our case further confirms the potential for Capnocytophaga to cause systemic infections, highlights the availability and need for identification of isolates to species level and re-emphasises the difficulty in diagnosing Capnocytophaga infections due to their slow growth in the laboratory.

Capnocytophaga canimorsus: a human pathogen feeding at the surface of epithelial cells and phagocytes

Capnocytophaga canimorsus, a commensal bacterium of the canine oral flora, has been repeatedly isolated since 1976 from severe human infections transmitted by dog bites. Here, we show that C. canimorsus exhibits robust growth when it is in direct contact with mammalian cells, including phagocytes. This property was found to be dependent on a surface-exposed sialidase allowing C. canimorsus to utilize internal aminosugars of glycan chains from host cell glycoproteins. Although sialidase probably evolved to sustain commensalism, by releasing carbohydrates from mucosal surfaces, it also contributed to bacterial persistence in a murine infection model: the wild type, but not the sialidase-deficient mutant, grew and persisted, both when infected singly or in competition. This study reveals an example of pathogenic bacteria feeding on mammalian cells, including phagocytes by deglycosylation of host glycans, and it illustrates how the adaptation of a commensal to its ecological niche in the host, here the dog's oral cavity, contributes to being a potential pathogen.

Capnocytophaga canimorsus is a commensal bacterium of dogs/cats oral flora, which causes rare but severe infections in humans that have been bitten or simply licked by a dog/cat. Fulminant septicemia and peripheral gangrene are most common symptoms. Although splenectomy has been identified as a predisposing factor, some 40% of the patients have no immunosuppression history. C. canimorsus belongs to the phylum Bacteroidetes, which includes many commensals of the human gut flora but few pathogens. C. canimorsus has been shown previously to be immunosuppressive and to resist phagocytosis by macrophages. Here, we show that this bacterium feeds on surface-exposed glycoproteins from cultured mammalian cells. This property, which was found to depend on a bacterial surface-exposed sialidase, suggests that in its natural niche—the dog's oral cavity—C. canimorsus may feed on the dog's mucosal cells. Moreover, we found that C. canimorsus also feeds on phagocytes and that sialidase contributes to persistence and virulence in a mouse infection model. Thus, by adapting to its ecological niche, C. canimorsus also developed the potential to persist within the tissues of an infected host. This observation nicely illustrates how commensalism and pathogenesis are two faces of the same coin.

Capnocytophaga canimorsus resists phagocytosis by macrophages and blocks the ability of macrophages to kill other bacteria

Capnocytophaga canimorsus is a commensal bacterium from the canine oral flora, which can cause septicemia or meningitis in humans upon bite wound infections. C. canimorsus 5 (Cc5), a strain isolated from a patient with fatal septicemia, was used to investigate the interaction between C. canimorsus and J774.1 mouse macrophages. J774.1 cells infected at high multiplicity with Cc5 did not phagocytose nor kill Cc5 within 120 min of infection, unless the bacteria were opsonized with specific antibodies. Opsonization with complement, however, did not increase phagocytosis. Moreover, infection of J774.1 cells with live Cc5 led to the release of a soluble factor, which interfered with the ability of macrophages to kill other phagocytosed bacteria. These results provide an example of how C. canimorsus neutralizes the innate immune system.

Capnocytophaga cynodegmi in a rottweiler dog with severe bronchitis and foreign-body pneumonia

Capnocytophaga cynodegmi is a zoonotic, gram-negative, capnophilic bacterium that is usually seen in people with infections associated with dog or cat bites. The first reported case of C. cynodegmi infection in a dog is described here.

Genetic tools for studying Capnocytophaga canimorsus

Capnocytophaga canimorsus, a commensal bacterium from canine oral flora, has been isolated throughout the world from severe human infections caused by dog bites. Due to the low level of evolutionary relationship to Proteobacteria, genetic methods suitable for the genus Capnocytophaga needed to be established. Here, we show that Tn4351, derived from Bacteroides fragilis, could be introduced by conjugation into C. canimorsus and conferred resistance to erythromycin. By mapping and sequencing a naturally occurring plasmid isolated from a clinical isolate of C. canimorsus, we identified a repA gene that allowed us to construct Escherichia coli-Capnocytophaga shuttle vectors. Most commonly used antibiotic markers were not functional in C. canimorsus, but cefoxitin (cfxA), tetracycline (tetQ), and erythromycin (ermF) resistances could be used as markers for plasmid maintenance in C. canimorsus and even in some other Capnocytophaga spp. Shuttle vectors were introduced into C. canimorsus either by conjugation using the origin of transfer (oriT) of RP4 or by electrotransformation. Taking advantage of the promoter of ermF, an expression vector was constructed. Finally, a method that allows site-directed mutagenesis is described. All these genetic tools pave the way, not only for molecular studies of the pathogenesis of C. canimorsus, but also for studies of other oral Capnocytophaga species.

Capnocytophaga spp. DF-1 pneumonia in an immune-competent 56-year old man post-CABG

We report a case of a nosocomial Capnocytophaga spp. DF-1 pneumonia in an intubated 56-year-old man following coronary artery bypass grafting. We review Capnocytophaga spp., including the infections they produce and antibiotic susceptibilities.

The Prevention and Management of Infections in Children with Asplenia or Hyposplenia

Overwhelming sepsis remains a significant complication of asplenia and hyposplenia. The mainstays of prevention are education, immunization, and prophylactic antibiotics. Evidence to base recommendation and guidelines is lacking. Such decisions as the specific immunizations required, the timing of immunizations, the duration of antibiotic prophylaxis, and the prevention of overwhelming postsplenectomy sepsis in children undergoing splenectomy are often empiric. This article reviews the current literature on the prevention and management of severe infections in children with underlying asplenia or hyposplenia.

Meningitis caused by Capnocytophaga canimorsus: When to expect the unexpected

In this article we review the available data concerning meningitis caused by Capnocytophaga canimorsus. The clinical presentation of this rare condition is described with the emphasis on associated conditions and management issues. Two additional cases, illustrating the difficulties in recognizing this rare disease, are presented. Reviewing a total of 28 reported cases, a preceding bite-incident by a cat or dog, or close contact with these animals, was described in the majority of cases (89%). Patients had a median age of 58 years; splenectomy and alcohol abuse were noted in, respectively, 18% and 25% of patients. Only in one case immune suppressive drug use was reported. The diagnosis C. canimorsus meningitis should be considered in healthy and immunocompromised adults, especially after splenectomy, who present with symptoms attributable to meningitis and a history of recent exposure to dogs or cats. The possibility of this condition has implications for both the diagnostic work-up and the treatment of the patient.

Zoonoses in Solid-Organ and Hematopoietic Stem Cell Transplant Recipients

Numerous reports exist of the transmission of zoonoses to humans during and after solid-organ and hematopoietic stem cell transplantation. Donor-derived infections of numerous etiologies, including West Nile virus infection, Chagas disease, toxoplasmosis, rabies, lymphocytic choriomeningitis virus infection, and infection due to Brucella species have been reported. Most zoonoses occur as a primary infection after transplantation, and immunocompromised patients are more likely to experience significant morbidity and mortality from these infections. Risks of zoonotic infection in the posttransplantation period could be reduced by patient education. Increased recognition of the risks of zoonoses, as well as the advent of molecular biology-based testing, will potentially augment diagnostic aptitude. Documented zoonotic infection as it affects transplantation will be the primary focus of this review.

Emergency Management of Difficult Wounds: Part I

Emergency physicians treat millions of wounds annually in the United States. In 2004 approximately 6.4 million open wounds were seen in United States emergency departments, representing approximately 5.8% of all visits. This article discusses difficult traumatic wounds that emergency physicians encounter on a daily basis, including mammalian bites, puncture and high-pressure wounds, and crush injuries, with special emphasis given to individuals at high risk for infectious complications. Information is provided on epidemiology, pathophysiology, management, and treatment of various complicated wounds. The authors highlight available guidelines, provide the best evidence available, and provide recommendations when data are limited.

Antimicrobial treatment of Capnocytophaga infections

Capnocytophaga spp. are normal inhabitants of the oropharyngeal flora. They are also involved in periodontal diseases or animal bites, complicated by septicaemia with dissemination to a great variety of sites, both in immunocompetent and immunocompromised hosts. This review will focus on their pathogenesis, spectrum of clinical infections and susceptibility to disinfectants and antibiotics. The spread of beta-lactamase-producing strains limits the use of beta-lactams as first-line treatments, underlying the necessity to test the in vitro susceptibility of clinical strains. Many antimicrobial treatments have been used, despite an absence of randomised studies and guidelines regarding the duration of treatment according to infected sites. Imipenem/cilastatin, clindamycin or beta-lactamase inhibitor combinations are always effective and their use can be recommended in all infections.

Early cystic lung disease in a premature neonate with perinatally acquired capnocytophaga

We describe a premature infant with early cystic lung lesions and sepsis due to prenatally acquired Capnocytophaga infection. Early cystic lesions have not been described previously as a characteristic of this infection.

Disseminated nontuberculous mycobacterial infections in sickle cell anemia patients

Nontuberculous mycobacteria (NTM) are ubiquitous in nature and have been implicated in skin/soft-tissue, pulmonary, middle ear, bone, and surgical/traumatic wound infections. Disseminated disease occurs infrequently and almost exclusively in the immunocompromised. We describe the first 2 reported cases of disseminated Mycobacterium fortuitum infection in teenagers with sickle hemoglobinopathy. Both had central venous catheters (CVCs), frequent admissions for vaso-occlusive painful episode and received hydroxyurea. Diagnosis was confirmed by multiple positive blood cultures and pulmonary dissemination occurred in both. Both had successful treatment after CVC removal and combination drug therapy. Positive cultures persisted in 1 patient due to drug resistance emphasizing the need for accurate susceptibility data. NTM infection should be added to the list of pathogens in sickle cell patients with CVCs and fever. Investigation for disseminated disease should be undertaken based on clinical signs and symptoms. Although some routine blood culture systems can identify NTM, specific mycobacterial blood culture is optimal. Removal of involved CVCs is essential and treatment of NTM must be guided by susceptibilities. As dissemination almost always occurs in those with impaired cellular immunity, human immunodeficiency virus testing should be performed. Hydroxyurea may be a risk factor for dissemination and needs further evaluation.

Capnocytophaga canimorsus meningitis after routine myelography: a sentinel event identifies multiple opportunities for improvement of standard practices in radiology

Meningitis developed after a routine myelogram in a healthy patient. When Capnocytophaga canimorsus was identified, investigations revealed that the patient, the radiologist, and the staff were all dog owners. Multiple deviations from recommended practices in radiology were identified and corrected. The investigation of an unusual sentinel event allowed multiple interventions to be implemented simultaneously, with resultant risk reduction for subsequent radiologic procedures.

The dangers of dog bites

This report describes an unusual case of endocarditis caused by Capnocytophaga canimorsus as a result of dog bite. The diagnosis could be established only by molecular techniques after amplification of bacterial DNA from the infected cardiac valve. The epidemiology and management of Capnocytophaga infections is discussed, as well as the role of prophylactic antibiotics in preventing these infections after dog bites.

First documented Capnocytophaga canimorsus infection in a species other than humans

Capnocytophaga canimorsus was cultured from an infected, dog-inflicted bite wound in a pet rabbit. The wound was treated successfully and the rabbit recovered. To our knowledge, this is the first report of a C. canimorsus infection in a species other than humans.

Meningitis due to Capnocytophaga canimorsus: contribution of 16S RNA ribosomal sequencing for species identification

We report a case of Capnocytophaga canimorsus meningitis, which is distinguishable from previous reports by the use of 16S rRNA sequencing for species identification. Our case report highlights the interest of molecular new tools for bacteriological diagnosis of human infections.

[Extensive purpura and septic schock in two patients with Capnocytophaga canimorsus]

INTRODUCTION

Capnocytophaga canimorsus is a Gram negative bacillus present in oral flora and in saliva of dogs and cats. It can be responsible for septicaemia and meningitides in some patients after dog or cat bite two patient with a septic shock due to C. canimorsus, who presented with an extensive pupura are reported.

CASE REPORT

A 50 year-old man with a past history of splenectomy was referred to an emergency department for a shock with vomiting, abdominal pain and generalized ecchymotic purpura culture samples isolated C. canimorsus in peritoneal fluid. Purpura occurred secondary to a disseminated intravascular coagulation. Despite intensive care and major antibiotherapy, the patient rapidly died. Four days previously, the patient administered pills in his dog mouth. The second patient was a 39 year old alcoholic man who was hospitalised for vomiting and septic shock witch occurred 24 hours after a dog bite. He presented with a livido and a diffuse purpura associated with necrotic lesions. Cultures of blood samples isolated C. canimorsus.

CONCLUSION

These severe infections due to C. canimorsus should be avoided by the routine use of early antibiotherapy with amoxicilline and clavulanic acid in patients with dog or cat bite, particularly if patient with associated debilitating disorders.

The prevention and treatment of bacterial infections in children with asplenia or hyposplenia: practice considerations at the Hospital for Sick Children, Toronto

Children born without a spleen or who have impaired splenic function, due to disease or splenectomy, are at significantly increased risk of life-threatening bacterial sepsis. The mainstays of prevention are education, immunization, and prophylactic antibiotics. The availability of conjugate 7-valent pneumococcal vaccines for use in children to age 9 years at least, as well as conjugate meningococcal C vaccine in some countries, for use beginning in infancy, appear to represent beneficial additions, but not substitutions, to previous recommendations for the use of polysaccharide 23-valent pneumococcal and quadrivalent A, C, Y, W-135 vaccines. Routine immunization against H. influenzae type b should continue with non-immunized children older than age 5 years receiving two doses 2 months apart, similar to children who have not previously received conjugate pneumococcal vaccine in infancy. Annual influenza immunization, which reduces the risk of secondary bacterial infection, is also recommended for asplenic children and their household contacts. Many experts continue prophylaxis indefinitely although prophylaxis of the penicillin allergic child remains suboptimal.

Capnocytophaga canimorsus mycotic abdominal aortic aneurysm: why the mailman is afraid of dogs

We describe the first case report of a mycotic abdominal aortic aneurysm secondary to Capnocytophaga canimorsus in an immunocompetent 65-year-old man. The exposure occurred after his dog scratched his arm and subsequently licked the wound. A review of C. canimorsus, a rarely pathogenic but potentially devastating bacterium, is also presented.

Diagnosing Capnocytophaga canimorsus infections

We reviewed clinical and epidemiologic features of 56 human Capnocytophaga canimorsus isolates submitted during a 32-year period to California's Microbial Diseases Laboratory for identification. An increasing number of isolates identified as C. canimorsus have been submitted since 1990. Many laboratories still have difficulty correctly identifying this species.

Méningite à Capnocytophaga canimorsus sans notion de morsure de chien

INTRODUCTION

Capnocytophaga canimorsus is a fusiform and filamentous gram-negative rod, part of the normal oral flora of dogs and cause rare human febrile acute meningitis, usually severe but curable.

OBSERVATION

A sixty years old man presented a severe acute meningitis with fever and confusion. CSF show 4,000 cells/mm3 with 83% neutrophilis, increased protein level (5,02 g/L), very low glucose and positive Gram stain result. The patient fully and quickly recovered with antibiotherapy for 22 days. Bacteriological diagnosis was made by genomic study from CSF culture. The patient has a close contact with his dog without being recently bitten.

DISCUSSION

Diagnosis, suggested by bites or contact with dog or cat, gram-negative bacilli with gram stain of CSF specimen, is possible by prolonged culture of CSF or blood sample, with if necessary genomic study. Antibioprophylaxis is strongly recommended in cases of deep bite wounds and for immunocompromised patients.

Lower respiratory tract infection due to Capnocytophaga cynodegmi in a cat with pulmonary carcinoma

A 10-year-old male castrated domestic shorthair cat was evaluated for coughing and lethargy. Thoracic radiographs revealed a soft tissue lung mass and diffuse peribronchial infiltrates. Bronchoscopy was performed and Capnocytophaga cynodegmi was cultured from bilateral bronchoalveolar lavage samples. Clinical signs and bacterial colonization resolved following treatment with enrofloxacin. A lung lobectomy was performed to remove the lung mass, which was diagnosed as pulmonary carcinoma. C cynodegmi is most frequently isolated from localized wound and corneal infections in humans. Specialized growth characteristics of C cynodegmi may result in low sensitivity for bacterial culture. To the authors' knowledge, this case represents the first report of C cynodegmi infection in a veterinary patient and only the second case in human or veterinary medicine where the organism has been isolated from a bronchoalveolar lavage sample. Based on this report, Capnocytophaga species should be considered as potential opportunistic pathogens.

Un choc septique d’étiologie inhabituelle : Capnocytophaga canimorsus. Le chien est-il toujours le meilleur ami de l'homme ?

The mortality of overwhelming postsplenectomy infections (OPSI) is significant (50 to 80 percent). Capnocytophaga canimorsus belongs to the normal oral flora of dogs and cats. It is seldom responsible for human infections, but its prognosis is bad (about 30 percent of overall mortality), especially in asplenic patients. We report a case of a splenectomized patient who suffered from communal septic shock due to C. canimorsus septicaemia. The course of events was rapidly fatal. Diagnosis and mode of contamination were determined only a few weeks after the patient's death. This late microbiological diagnosis is due to a slow growth of C. canimorsus in vitro.

Tenosynovitis caused by Mycobacterium kansasii associated with a dog bite

A 68-year-old man with adult-onset diabetes mellitus suffered an accidental puncture wound to the palm of his hand while playing with his pet dog. He received cephalosporin prophylaxis for 1 week. No inflammation occurred. Six months later, a mass developed near his elbow. It was removed. Histopathology revealed granulomas containing acid-fast bacilli (AFB). No culture was done. Swelling and decreased motion of the wrist and fingers developed. Magnetic resonance imaging revealed inflammation of the flexor compartment of the hand, wrist, and forearm. Surgical incision and drainage yielded purulent material, granulomatous inflammation, with AFB. Cultures yielded Mycobacterium kansasii. Several surgical procedures were required; M kansasii was recovered. He received isoniazid and rifampin for 1 year and prolonged rehabilitation. After 4 years, he was relatively asymptomatic, with good function of wrist and fingers. We believe this to be the first report of tenosynovitis caused by M kansasii in association with a dog bite.