Biomedical subjects

Bruno Chomel

Publications and source records attributed to Bruno Chomel.

6 recordsLinked to original sources

PubMed2006

A Bartonella vinsonii berkhoffii typing scheme based upon 16S-23S ITS and Pap31 sequences from dog, coyote, gray fox, and human isolates.

Since the isolation of Bartonella vinsonii subspecies berkhoffii from a dog with endocarditis in 1993, this organism has emerged as an important pathogen in dogs and as an emerging pathogen in people. Current evidence indicates that coyotes, dogs and gray foxes potentially serve as reservoir hosts. Based upon sequence differences within the 16S-23S ITS region and Pap31 gene, we propose a classification scheme that divides B. vinsonii subsp. berkhoffii isolates into four distinct types. Two conserved sequences, of 37 and 18 bp, respectively, are differentially present within the ITS region of each of the four B. vinsonii subsp. berkhoffii types. To date, B. vinsonii berkhoffii types I, II, and III have been identified in the US, type III in Europe and type IV in Canada. Based upon the proposed genotyping scheme, the geographic distribution of B. vinsonii berkhoffii types needs to be more thoroughly delineated in future molecular epidemiological studies involving Bartonella infection in coyotes, dogs, gray foxes, human beings and potentially other animals or in arthropod vectors. Strain typing may help to better define the reservoir potential, carriership patterns, modes of transmission, and geographic distribution for each B. vinsonii berkhoffii type.

Animals↗

PubMed2006

Serological survey of vector-borne zoonotic pathogens in pet cats and cats from animal shelters and feral colonies.

Although cats and their arthropod parasites can sometimes be important sources of zoonotic diseases in humans, the extent of exposure among various cat populations to many potential zoonotic agents remains incompletely described. In this study, 170 domestic cats living in private homes, feral cat colonies, and animal shelters from California and Wisconsin were evaluated by serology to determine the levels of exposure to a group of zoonotic vector-borne pathogens. Serological positive test results were observed in 17.2% of cats for Rickettsia rickettsii, 14.9% for R akari, 4.9% for R typhi, 11.1% for R felis, and 14.7% for Bartonella henselae. Although vector-borne disease exposure has been documented previously in cats, the evaluation of multiple pathogens and diverse cat populations simultaneously performed here contributes to our understanding of feline exposure to these zoonotic pathogens.

Animals↗

PubMed2004

[Bartonellosis: emerging infection].

The spectrum of Bartonella infections in humans shows a constant increase. The number of Bartonella species responsible of zoonoses has increased from one to 7 during the past ten years. In addition numerous orphan clinical manifestations are now associated to Bartonella henselae infections. Animals and particularly domestic cat are the main reservoirs of Bartonella. Cats are healthy carriers of B. henselae and B. clarridgeiae, and can be bacteremic for months to years. Cat-to-cat transmission of the bacteria involves the cat flea in ab-sence of transmission by direct contact. Present knowledge on the etiology, clinical features and epidemiological characteristics of these emerging infections are presented.

Animals↗

PubMed2004

Role of Hippoboscidae flies as potential vectors of Bartonella spp. infecting wild and domestic ruminants.

The putative role of biting flies in Bartonella transmission among ruminants was investigated. Amplification of the Bartonella citrate synthase gene from 83 Hippoboscidae was detected in 94% of 48 adult Lipoptena cervi flies, 71% of 17 adult Hippobosca equina flies, 100% of 20 adult Melophagus ovinus flies, and 100% of 10 M. ovinus pupae. Our findings suggest that Hippoboscidae play a role in the transmission of Bartonella among ruminants. The vertical transmission of Bartonella in M. ovinus and the presence of Bartonella DNA in all samples suggest a symbiotic association between Bartonella and M. ovinus.

Animals↗

PubMed2004

Exposure to feline and canine pathogens in bobcats and gray foxes in urban and rural zones of a national park in California.

Exposure of bobcats (Lynx rufus) and gray foxes (Urocyon cinereoargenteus) to a range of common canine and feline pathogens was assessed in urban and rural zones of Golden Gate National Recreation Area, a National Park in the San Francisco Bay Area, (California, USA) from 1992 to 1995. Testing included serology for canine distemper virus, canine parvovirus (CPV), canine adenovirus, Leptospira interrogans, feline calicivirus (FCV), feline panleukopenia virus, feline herpesvirus, feline enteric coronavirus (FECV), feline immunodeficiency virus, feline leukemia virus, Toxoplasma gondii, and Bartonella henselae. Testing was also performed for Dirofilaria immitis. Significantly more gray foxes were seropositive for CPV in the urban zone than in the rural zone. In addition, radio-tracking of gray foxes in the rural zone indicated that all three of the rural CPV-seropositive foxes had traveled into adjoining small towns, whereas only one of the 11 seronegative animals had done so. Significantly more bobcats were seropositive for FCV in the rural zone than in the urban zone. Individual bobcats with positive FCV antibody titers had patterns of movement that intercepted park inholdings where domestic cats lived. Bobcat samples were seronegative for all five of the other viral feline pathogens, with the exception of a FECV-seropositive bobcat. High seroprevalence was detected for B. henselae and T. gondii in both zones. Variation in the seroprevalence for different pathogens might be related to differences in the exposure of bobcats and foxes to domestic animals: in the urban zone, gray foxes were located in residential areas outside the park, whereas bobcats were not. Although for most of the pathogens examined there was no relationship between urbanization and exposure, our results for CPV in foxes and FCV in bobcats indicated that proximity to urban areas or contact with humans can increase the risk of disease exposure for wild carnivore populations. Combining behavioral information from radio-tracking with data on pathogen exposure or disease incidence can provide valuable insights into the ecology of wildlife disease that might be missed with broad-scale, population-level comparisons alone.

Animal Identification Systems↗

PubMed2003

The immunologic response of dogs to Bartonella vinsonii subspecies berkhoffii antigens: as assessed by Western immunoblot analysis.

Bartonella vinsonii subspecies berkhoffii is a recently recognized zoonotic pathogen that causes endocarditis, granulomatous rhinitis, and granulomatous lymphadenitis in dogs. Isolation of B. vinsonii (berkhoffii) from blood or tissue samples is frequently unsuccessful; therefore, diagnosis is primarily dependent on serologic or molecular testing modalities. Because previous canine serologic studies have used an indirect immunofluorescence assay (IFA), without Western immunoblot (WI) confirmation, the overall objective of this study was to examine the diagnostic use of WI for confirmation of B. vinsonii (berkhoffii) infection in dogs. To confirm that agar-grown and cell culture-grown organisms yielded similar patterns of WI antigenic protein recognition, the 2 preparations were compared using IFA-reactive sera obtained from dogs experimentally infected with B. vinsonii (berkhoffii). Temporal changes in the pattern of antigenic protein recognition were characterized using sera obtained from dogs at various time points after experimental B. vinsonii (berkhoffii) infection. The specificity of B. vinsonii (berkhoffii) WI was examined by testing canine sera that were reactive to B. henselae, B. clarridgeiae, Ehrlichia canis, Rickettsia rickettsii, Babesia canis, Anaplasma phagocytophilum (previously E. equi), or Brucella canis antigens. Clinical accessions including serum samples obtained from B. vinsonii (berkhoffii) culture-positive dogs and B. vinsonii (berkhoffii) culture-negative dogs that were IFA seroreactive to B. vinsonii (berkhoffii) antigens were examined by WI. The results of this study indicate that WI using agar-grown or cell culture-grown B. vinsonii (berkhoffii) antigens produce identical patterns of antigenic protein recognition. After experimental infection, there is a progressive increase in the number of antigenic proteins that are recognized by WI, with the 33-kD antigen representing the first and the most persistent antigen recognized by B. vinsonii (berkhoffii)-infected dogs. Regarding specificity, sera from dogs that were reactive to various heterologous antigens did not recognize B. vinsonii (berkhoffii) antigens by IFA or WI, and sera from dogs experimentally infected with B. henselae did not recognize B. vinsonii (berkhoffii) antigens by WI. Regarding clinical accessions, there was good agreement between B. vinsonii (berkhoffii) IFA test results and WI analysis. Western immunoblot analysis can be used to detect or confirm exposure to B. vinsonii (berkhoffii) in dogs.

Animals↗