Capnocytophaga canimorsus septic shock complicated by multiorgan failure: an unexpected case with a favourable outcome

Background: The aim of our report was to describe an unusual and exemplary case of Capnocytopha-ga canimorsus septic shock in a patient who has not been exposed to dogs or cats. Case report: A splenectomized 60-year-old male without a known at-risk bite wound was diagnosed with C. canimorsus septic shock, complicated by multiorgan failure and disseminated intravascular coag-ulation. The patient was empirically treated and recovered without sequelae. The favorable outcome was related to a prompt diagnosis and a timely treatment, despite the absence of epidemiological and suspi-cion clues. A narrative review and case series demonstrates that only one previous article has reported a case of bacteremia and meningitis without a dog bite in an immunocompetent individual. Conclusions: It is important to recognize any case of C. canimorsus sepsis in splenectomized patients, particu-larly those presenting with fulminant sepsis, even without a history of dog bites, scratches and licks

Septic shock caused by Capnocytophaga canis after a cat scratch

Capnocytophaga canis is an uncommon cause of septic shock. Only three cases have been previously reported in the literature. In this article, we describe the case of a 70-year-old male admitted to the intensive care unit for septic shock of unknown origin. On day 2, one anaerobic bottle out of the two sets taken at admission turned positive with Gram-negative bacilli. The pathogen was identified by 16S rRNA gene as C. canis. The strain was characterized and compared with other clinical isolates of Capnocytophaga spp

Capnocytophaga canimorsus : genomic characterization of a specialised host-dependent lifestyle and implications in pathogenesis

Here is presented the complete 2,571,405-bp genome sequence of Capnocytophaga canimorsus strain 5 (Cc5), a strain that was isolated from a fatal septicaemia. Phylogenetic analysis of conserved genes supports the inclusion of C. canimorsus into the Cytophaga-Flavobacteria-Bacteroides (CFB) phylum and indicates close relationships with environmental flavobacteria as Flavobacterium johnsoniae and Gramella forsetii. In addition, relative phylogenetic topology of Capnocytophaga species shows that C. canimorsus share more sequence similarities with human host associated Capnocytophaga species than species from the latter group among themselves (e.g. C. gingivalis and C. ochracea). As compared to other Capnocytophaga, C.canimorsus seems to have differentiated by large-scale horizontal gene transfer compensated by gene losses. Consistently with a relatively reduced genome size, genome scale metabolic modelling suggested a reduced global pleiotropy as it is illustrated by the presence of a split TCA cycle or by the metabolic uncoupling of the hexoses and N-acetylhexosamines pathways. In addition and in agreement with the high content in HCO3- and Na+ ions in saliva, we predicted a CO2-dependent fumarate respiration coupled to a Na+ ions gradient based respiratory chain in Cc5. All together these observations draw the picture of an organism with a high degree of specialization to a relatively homeostatic host environment. Unexpectedly, the genome of Cc5 did not encode classical complex virulence functions as T3SSs or T4SSs. However it exhibits a very high relative number of predicted surface-exposed lipoproteins. Many of them are encoded within 13 different putative polysaccharide utilization loci (PULs), a hallmark of the CFB group, discovered in the gut commensal Bacteroides thetaiotaomicron. When Cc5 bacteria were grown on Hek293 cells, at least 12 PULs were expressed and detected by mass spectrometry. Semi-quantitative analysis of the Cc5 surfome identified 73 surface exposed proteins among which 40 were lipoproteins and accounted for 76% of the total quantification. Interestingly, 28 proteins (38%) were encoded by 9 different PULs and corresponded to more than 54% of total MS-flying peptides detected. A systematic knockout analysis of the 13 PULs revealed that 6 PULs are involved in growth during cell culture infections with most dramatic effect observed for ΔPUL5. Proteins encoded by PUL5, one of the most abundant PULs (12%), turned out to be devoted to foraging glycans from N-linked glycoproteins as fetuin but also IgG. It was not only essential for growth on cells but also for survival in mice and in fresh human serum therefore representing a new type of virulence factor. Further characterization of the PUL5 deglycosylation mechanism revealed that deglycosylation is achieved by a large surface complex spanning the outer membrane and consisting of five PUL5 encoded Gpd proteins and the Siac sialidase. GpdCDEF contribute to the binding of glycoproteins at the bacterial surface while GpdG is a β-endo-glycosidase cleaving the N-linked oligosaccharide after the first N-linked GlcNAc residue. We demonstrate that GpdD, -G, -E and -F are surface-exposed outer membrane lipoproteins while GpdC resembles a TonB-dependent OM transporter and presumably imports oligosaccharides into the periplasm after cleavage from glycoproteins. Terminal sialic acid residues of the oligosaccharide are then removed by SiaC in the periplasm. Finally, degradation of the oligosaccharide proceeds sequentially from the desialylated non reducing end by the action of periplasmic exoglycosidases, including β-galactosidases, β-N-Acetylhexosaminidases and α-mannosidases. Genome sequencing of additional C. canimorsus strains have been performed with the only use of second generation sequencing methods (Solexa and 454). Two assembling approaches were developed in order to enhance assembly capacities of pre-existing tools. Draft assemblies of the three pathogenic human blood isolates C. canimorsus 2 (three contigs), C. canimorsus 11 (152 contigs) and C. canimorsus 12 (63 contigs) are presented here. Comparative genomics including genomes of four available human hosted Capnocytophaga species stressed C. canimorsus exclusively conserved features as an oxidative respiratory chain and an oxidative stress resistance or the presence of a Cc5 specific PULs content. Therefore we propose these features as potential factors involved in the pathogenesis of C. canimorsus

First reported case of <i>Capnocytophaga canimorsus</i> pituitary abscess

Background: Capnocytophaga canimorsus is a rare human pathogen, typically associated with exposure to dog saliva. It is a slow-growing, Gram-negative anaerobe, with clinical manifestations being sepsis, meningitis, or endocarditis. Pituitary abscesses are themselves uncommon, accounting for &lt;1% of all pituitary lesions, and are often misdiagnosed preoperatively due to their nonspecific presentation and frequent culture negativity. We present the first documented case of a pituitary abscess caused by C. canimorsus, highlighting the diagnostic value of 16S ribosomal RNA (rRNA) polymerase chain reaction (PCR) when conventional microbiological methods are inconclusive. Case Description: A 69-year-old woman presented following a collapse with symptoms including hypernatremia, new-onset atrial fibrillation, and thyrotoxicosis. Initial sepsis workup–including cerebrospinal fluid analysis–suggested possible encephalitis. Brain magnetic resonance imaging revealed a cystic, contrast-enhancing pituitary lesion with central diffusion restriction. The patient underwent endoscopic transsphenoidal surgery, with intraoperative findings consistent with abscess formation. Despite direct culture yielding no growth, 16S rRNA PCR of the aspirated fluid identified C. canimorsus. Histology revealed xanthogranulomatous inflammation. The patient was treated with a 6-week course of intravenous ceftriaxone, with subsequent clinical and radiological recovery. Importantly, she had no known exposure to animal bites or saliva and no underlying immunosuppressive condition. Conclusion: This case is the first to implicate C. canimorsus in the formation of a pituitary abscess, expanding the spectrum of its potential clinical presentations. It underscores the diagnostic limitations of conventional microbiological techniques in deep-seated intracranial infections and supports the role of 16S rRNA PCR as a critical adjunct when routine cultures are negative. Clinicians should maintain a high index of suspicion for atypical pathogens in sellar lesions and consider molecular diagnostics early, particularly when histopathology reveals inflammatory features suggestive of infection without an identifiable organism

Important Canine Zoonoses from a Public Health Perspective and the Introduction of Companion Animal Surveillance in the Prairie Provinces of Canada

ABSTRACT Prioritizing zoonotic and/or sapronotic pathogens of domestic animal populations and initiating ongoing surveillance of such pathogens is needed in Canada. From a One Health perspective, gathering and recording more comprehensive disease data on the population of animals most closely associated with humans is extremely valuable and necessary. Therefore, the purpose of this thesis was to identify a subset of domestic canine pathogens of public health significance specific to the Prairie Provinces of Canada and to establish a framework for a companion animal surveillance initiative to the region. This research was conducted within a two- year period from September 2019 to April 2021. The first component of this research involved the creation of a comprehensive list of any pathogen historically reported in the domestic dog by reviewing several companion animal infectious disease textbooks, which resulted in 594 pathogens total. This list was then pared down to identify only those pathogens that were significant from a public health perspective in Canada and the prairies. This was accomplished using a formulated stepwise approach that pathogens only moved on to the final list if: (1) the pathogen was zoonotic/sapronotic/anthroponotic, (2) the domestic dog was involved in transmission, maintenance or detection of the pathogen, and (3) there was a level of risk for occurrence of the pathogen in Canada. Following this stepwise approach, of the initial 594 canine pathogens 84 pathogens were deemed important in Canada and the prairies from a public health perspective. A follow-up study to this research involved a prioritization exercise using experts in the field of veterinary medicine, public health, and epidemiology to identify the top 5 highest priority pathogens from the final list of 84 canine pathogens upon which to focus a companion animal surveillance program specific to the Prairie Provinces. The exercise was accomplished through a voluntary survey using a semi-quantitative ranking strategy. The resulting top 5 pathogens to come out of the exercise were: (1) Echinococcus spp. (granulosus, multilocularis), (2) MRSA, (3) Salmonella enterica, (4) MRSP, and (5) Borrelia burgdorferi. The final component of this research examined the utility of clinical veterinarians and veterinary clinics in a companion animal surveillance program. In addition, responses from clinical veterinarians were used to formulate case definitions for the top 5 highest priority pathogens intended for surveillance. Assessing dogs as sentinels for pathogens of public health concern using Lyme disease as an example was also conducted in this research chapter. Data was gathered through a voluntary survey disseminated to clinical veterinarians in the provinces of Alberta, Saskatchewan, and Manitoba. The results of this survey identified that clinical veterinarians are willing to participate in a surveillance program, that there is important in-clinic veterinary data not currently being captured from a population or disease monitoring standpoint, and that domestic dogs can serve as good sentinels for Lyme disease risk in humans, specific to the prairies. This thesis provided the foundational steps for a companion animal surveillance initiative specific to the Prairie Provinces of Canada. It identified which pathogens involving the domestic dog pose a significant public health risk in Canada and the prairies, prioritized these pathogens from highest to lowest concern using expert opinion, and established the importance of cooperation with practicing veterinarians and veterinary clinics for a companion animal surveillance program to be successful

Clinical Manifestation and Management of Terrestrial Animal Bites

Background: Terrestrial animal bites wounds are injuries caused by terrestrial animals' mouths and teeth. Aerobic and nonaerobic bacteria cause 30–60% of the secondary bacterial infections due to animal bites. Rabies is an infectious disease and it is the most dangerous viral infection caused by animal bites. Also, venomous animal bites can be fatal and cause death if not treated well. Purpose: To identify the clinical manifestation, first aid, and management of terrestrial animal bites to reduce morbidity and mortality. Review: Wounds and crush injuries caused by animal bites are prone to infection. Aerobic bacteria, such as Pasteurella multocida, Staphylococcus spp. (including methicillin–resistant Staphylococcus aureus (MRSA)), Capnocytophaga canimorsus, and Bartonella henselae, and anaerobic bacteria, such as Porphyromonas spp. are commonly found pathogens in animal bite wounds. Rabies, the most dangerous viral infection, occurs in wounds infected by the rabies virus. The virus enters the nerve tissue, multiplies, and spreads to the central nervous system. This can cause disability, and it is life-threatening. In snakebites, management of basic life support, transportation to the hospital, clinical assessment, and immediate resuscitation are the most important procedures. Conclusion: Animal bite wounds are injuries caused by animals' mouths and teeth. Dogs, cats, and snakes are terrestrial animals that most likely attack humans. Proper diagnosis, first aid, and comprehensive management are needed to reduce morbidity and mortality

Zoonoses in dog and cat shelters in North-East Italy: update on emerging, neglected and known zoonotic agents

IntroductionShelters for stray dogs and cats deserve careful monitoring for zoonotic risk, as they represent a crucial point for prevention and control of infection spread. Data sorting to prioritize zoonotic agents in a geographic area need constant updating, but no regular official programs are ongoing, to allow an efficient risk survey for these animal species. This study aimed to conduct a comprehensive investigation of the prevalence of certain known, potential and emerging zoonoses within the framework of the routine monitoring of dog and cat shelters in North-East Italy.MethodsA total of 389 cats and 257 dogs housed in public veterinary services shelters and feline colonies were included in the present investigation. The animals originated from the provinces of Padua, Venice, Rovigo, Vicenza, Verona, Trento and Bolzano. Serological, molecular and microbiological diagnostics were implemented to investigate the prevalence of Leptospira sp., Brucella canis, Leishmania infantum, dermatophytes, gastrointestinal parasites, antimicrobial-resistant bacteria, Capnocytophaga sp., Bartonella sp., Norovirus, Rotavirus A, Cowpox virus, Mammalian Orthoreovirus, Hepatitis E virus, SARS-CoV-2 and Influenza A virus.ResultsData about some known zoonoses (e.g., serological positivity of Leishmania infantum 25% and Leptospira sp. 44.3% in dogs, and Bartonella henselae 70% in cats) resulted aligned with previous research and recent reports, whereas there was a notable occurrence of some potential, emerging and neglected pathogens (e.g., Mammalian Orthoreovirus 0.38% in dogs and 2.83% in cats). For some other agents (e.g., dermatophytes in dogs and in cats) the prevalence resulted lower than expected.DiscussionThe prevention of the zoonotic risk requires a re-examination of the complex interaction between humans, animals, and environment. This is of particular importance in settings like companion animal shelters, which serve as key sites for disease monitoring and zoonotic risk mitigation. The study highlights the need to monitor and prioritize the zoonotic pathogens, to implement and constantly update surveillance and specific training programs for the kennels’ operators, and management of epidemiological risks

A study on the bacteria of dog bite wounds in dogs and their susceptibility to antimicrobials

To investigate the bacterial composition of infected and non-infected dog bite wounds (DBW), a prospective study was performed on dogs with various grades of bite wounds presenting at the Onderstepoort Veterinary Academic Hospital, University of Pretoria, and a nearby animal shelter. Fifty dogs with bite wounds inflicted within the previous 72 hours were selected. This represented 104 wounds. Wounds were clinically graded according to severity. Swabs were collected from all wounds for bacterial culture and cytology. Infection was diagnosed if 2 of the following 3 criteria were met: macroscopic purulence, microscopic presence of phagocytosed bacteria, or pyrexia. Non-infected wounds were either classed as sterile (established by culture) or contaminated (culture positive but bacteria not phagocytosed on cytology). To determine the origin of the bacteria, swabs were collected from the skin near the wounds and gingiva of 15 bite victims. All swabs were cultured aerobically and anaerobically and all aerobic cultures were evaluated for antimicrobial susceptibility using the Kirby Bauer disk diffusion test. The victims were predominately male, uncastrated, small-breed dogs. Of the 104 wounds studied, 21 were judged to be infected and 83 non-infected. Infected wounds were significantly more likely to culture positive (Fisher's exact test: p = 0.02). Sixteen per cent of wounds did not culture bacteria, 67% grew aerobes only, 1% anaerobes only and 67% a mixture of aerobes and anaerobes. A total of 213 isolates were cultured representing a mean of 2 isolates per wound. Of the aerobe species cultured, 22%, 19% and 17% belonged to the genera of Pasteurella, Streptococcus and Staphylococcus respectively. The species of Pasteurella multocida (66%) and Staphylococcus intermedius (70%) were predominant. Pasteurella canis and pyogenic streptococci were common in infected wounds, whereas Bacillus spp., Actinomyces spp. and oral streptococci were usually found in contaminated wounds. Three anaerobic genera were cultured, namely, Prevotella, Clostridium and Peptostreptococcus, and were usually associated with wounds with dead space. This study also describes the first documented case of Capnocytophaga canimorsus in an infected dog bite wound. Notably clinical and cytological assessment was capable of establishing whether antimicrobials were required or not. Although no single antimicrobials was considered to be effective against all the bacteria, amoxycillin plus clavulanic acid, 1st and 3rd generation cephalosporins, ampicillin or amoxycillin and potentiated sulphonamides gave the best in vitro sensitivity results.Dissertation (MMedVet(Surgery) Small Animal Surgery)--University of Pretoria, 2007.Companion Animal Clinical Studiesunrestricte

Clin Infect Dis

BackgroundRickettsia rickettsii, Rickettsia parkeri, and Rickettsia akari are the most common causes of spotted fever group rickettsioses indigenous to the United States. Infected patients characteristically present with a maculopapular rash, often accompanied by an inoculation eschar. Skin biopsy specimens are often obtained from these lesions for diagnostic evaluation. However, a species-specific diagnosis is achieved infrequently from pathologic specimens because immunohistochemical stains do not differentiate among the causative agents of spotted fever group rickettsiae, and existing polymerase chain reaction (PCR) assays generally target large gene segments that may be difficult or impossible to obtain from formalin-fixed tissues.MethodsThis work describes the development and evaluation of a multiplex real-time PCR assay for the detection of these 3 Rickettsia species from formalin-fixed, paraffin-embedded (FFPE) skin biopsy specimens.ResultsThe multiplex PCR assay was specific at discriminating each species from FFPE controls of unrelated bacterial, viral, protozoan, and fungal pathogens that cause skin lesions, as well as other closely related spotted fever group Rickettsia species.ConclusionsThis multiplex real-time PCR demonstrates greater sensitivity than nested PCR assays in FFPE tissues and provides an effective method to specifically identify cases of Rocky Mountain spotted fever, rickettsialpox, and R. parkeri rickettsiosis by using skin biopsy specimens.CC999999/Intramural CDC HHS/United States2015-09-14T00:00:00Z24829214PMC456898