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B Chomel

Publications and source records attributed to B Chomel.

16 recordsLinked to original sources
PubMed2006

Effects of cow age and pregnancy on Bartonella infection in a herd of dairy cattle.

Bartonella spp. are small hemotropic bacteria infecting mammals. Four Bartonella species have been recently described in cattle and wild ruminants. To date, the biology and possible pathogenic role of Bartonella species isolated from ruminants are poorly understood. Therefore, a dairy herd of 448 cows and heifers was surveyed in order to establish the prevalence of Bartonella bovis and B. chomelii infections, the level of bacteremia, and the relationship between bacteremia and age or pregnancy status. The putative impact of Bartonella infection on production performance (individual milk cell count, milk yield) and reproductive status (success of artificial insemination [AI], placental retention, embryonic death, and abortion) was also assessed. The overall mean prevalence of B. bovis bacteremia was 59%, with the highest prevalence in heifers (92.5%). No B. chomelii was isolated, and 95% (114/120) of the B. bovis strains isolated and tested by PCR-restriction fragment length polymorphism belonged to type I. The level of bacteremia was higher in pregnant cows than in nonpregnant cows (P = 0.05), and the level of bacteremia rose during the last two-thirds of gestation (P < 0.001). There was no correlation between bacteremia and milk yield, individual milk cell count, success of first AI, interval between two calvings, or incidence of abortion and embryonic death. The interval from calving to first AI was shorter and the incidence of placental retention was lower in bacteremic animals than in nonbacteremic ones (P = 0.03 and P = 0.01, respectively).

Age Factors↗
PubMed2004

Identification of Bartonella strains isolated from wild and domestic ruminants by a single-step PCR analysis of the 16S-23S intergenic spacer region.

Of the 20 species or subspecies of Bartonella currently known, 7 cause various diseases in humans with many being zoonotic. However, some Bartonella species appear only to cause asymptomatic bacteraemia in their hosts. In ruminants, three Bartonella species (B. bovis, B. capreoli and B. schoenbuchensis) have recently been described. However, limited or no information has yet been published concerning their mode of transmission and their possible pathogenicity for domestic cattle. The phylogenetic relationship of these species with other bacteria of the Bartonella genus has only been recently investigated. It is therefore necessary to develop appropriate tools that will easily allow identification of these ruminant strains for epidemiological and clinical studies. A single-step PCR assay, based on the amplification of a fragment of the 16S-23S rRNA intergenic spacer (ITS), was evaluated for identification of Bartonella isolated from domestic cattle and from free-ranging or captive cervids. For each Bartonella species tested, the PCR assay led to a product that was unique either for its length or its sequence. All ruminant isolates tested could be easily differentiated among themselves and from the other Bartonella species. Furthermore, sequence analysis of the PCR products revealed a close relationship between all ruminant Bartonella strains. Therefore, ITS PCR testing appears to be a convenient tool for a quick diagnosis of ruminant Bartonella species.

Animals↗
PubMed2000

Bartonella birtlesii sp. nov., isolated from small mammals (Apodemus spp.).

Three strains isolated from Apodemus spp. were similar to Bartonella species on the basis of phenotypic characteristics. Futhermore, genotypic analysis based on sequence analysis of the 16S rRNA and gltA genes and on DNA-DNA hybridization showed that the three isolates represented a distinct and new species of Bartonella. The name Bartonella birtlesii is proposed for the new species. The type strain of B. birtlesii sp. nov. is IBS 325T (= CIP 106294T = CCUG 44360T).

Animals↗
PubMed1999

Bartonella alsatica sp. nov., a new Bartonella species isolated from the blood of wild rabbits.

Bartonella species are considered as emerging human pathogens, with at least six different species pathogenic or possibly pathogenic for humans. However, little is known about Bartonella distribution, species polymorphism and pathogenicity in mammalian species. The objective of this work was to determine the presence, the frequency and the distribution of Bartonella species in wild rabbits (Oryctolagus cuniculus) caught in warrens in Alsace, France. Humans may come into contact with wild rabbits when hunting, especially when they are picked up with bare hands and at time of evisceration. Of 30 blood samples collected and cultured from wild rabbits, nine (30%) were positive for organisms morphologically similar to Bartonella spp. The bacteria appeared as small, fastidious, aerobic, oxidase-negative, Gram-negative rods which could be localized within erythrocytes. Their biochemical properties were similar to those of the genus Bartonella. The sequence of the 16S rRNA gene obtained from the rabbit isolates was highly related to the sequences of the different Bartonella species (97.8-99.3% similarity). The high DNA hybridization rate (81-90% similarity) between the three strains isolated from rabbit blood confirmed that they belong to the same bacterial species. Hybridization values, obtained with the nuclease-TCA method, when testing type strains of recognized Bartonella species (9-14% similarity), support the creation of a new species for the rabbit isolates. The name Bartonella alsatica is proposed for these strains isolated from the blood of wild rabbits. The type strain is IBS 382T (= CIP 105477T).

Animals↗
PubMed1998

Seroprevalence of Bartonella henselae in cattery cats: association with cattery hygiene and flea infestation.

We attempted to determine what factors were common to catteries with high Bartonella henselae antibody prevalence compared with catteries with low prevalence, in order to contribute to better guidelines for the choice of a safe pet cat. The overall seroprevalence in 11 catteries from diverse geographical locations in North America in the present study was 35.8%. There was evidence of B. henselae exposure in all 11 homes tested, with 5 catteries being heavily infected. The distribution of B. henselae exposure was bimodal in catteries: either most or all cats in the home had been exposed, or very few or no cats had been exposed. Prevalence per home was also correlated with the home mean antibody titre. Flea infestation was the most important risk factor for high B. henselae seroprevalence in the catteries we surveyed. Individual cat titres were comparable for male and female cats, cats of various ages, and cats with concurrent infectious diseases. There was no association of B. henselae with cattery size, husbandry practices, presence or absence of rescued cats, dog ownership, attending cat shows, routine visits to a veterinarian, and outside travel. In summary, cattery cats can be easily identified as high or low risk to new potential cat owners.

Animal Husbandry↗
PubMed1998

Bartonella tribocorum sp. nov., a new Bartonella species isolated from the blood of wild rats.

Two Bartonella strains from blood of two wild rats (Rattus norvegicus) living in a rural environment were isolated. These strains were distinct from all previously known Bartonella species based on phenotypic and genotypic characteristics. This new species is distinguished by its trypsin-like activity, the absence of the ability to hydrolyse proline and tributyrin, its 16S rRNA and citrate synthase gene sequences and by whole-DNA hybridization data. This new species, for which the name Bartonella tribocorum sp. nov. is proposed, seems to be genetically related to Bartonella elizabethae, an agent isolated in a case of human endocarditis. The type strain of Bartonella tribocorum sp. nov. is IBS 506T (CIP 105476T).

Animals↗
PubMed1998

Molecular, clinical, and pathologic comparison of two distinct strains of Haemobartonella felis in domestic cats.

OBJECTIVE: To characterize 2 strains of Haemobartonella felis by use of molecular techniques. ANIMALS: 35 specific-pathogen-free cats, 6 months to 4 years old. PROCEDURE: Intraperitoneal or IV inoculation with blood containing H felis small form (Hfsm, 18 cats) or H felis large form (Hflg, 11 cats); 6 cats were uninfected controls. Hfsm was evaluated for capability to cross-protect against the more virulent Hflg. Morphology of both strains was compared by light microscopy of Wright-Giemsa-stained blood smears, and the 16S rRNA genes were sequenced. RESULTS: Infection with Hflg induced signs of depression, fever, and severe macrocytic normochromic anemia with nucleated erythrocytes. More than 95% of erythrocytes were parasitized. Inoculation with Hfsm and uninfected control blood induced mild or no clinical signs and no hematologic abnormalities. Anti-H felis IgG was first detected on postinoculation day (PID) 21, and increased to maximal titer of 400 by PID 28. Reactivated infection was observed in 8 of 29 cats (4 Hfsm and 4 Hflg), with 5% parasitized erythrocytes during the later attack. On PID 8, Hflg-inoculated cats had positive results of polymerase chain reaction analysis (PCR) that persisted until cats were treated with doxycycline or oxytetracycline; Hfsm-inoculated cats had positive PCR results that persisted for duration of observation (3 months). CONCLUSIONS: Genetically and morphologically distinct strains of H felis infect cats in the field. The level of genetic difference suggested that these strains may be different species or genera. CLINICAL RELEVANCE: PCR is a critical diagnostic aid to detect occult Haemobartonella spp infection, as well as response to treatment and clearance of the organism.

Anaplasmataceae↗
PubMed1991

[Veterinary epidemiology].

The author describes the specifics of veterinary epidemiology, in particular its domain and objectives. The large diversity of data sources are partly limited by the lack of standardized nomenclature and registries in many animal species. Even if veterinary epidemiology benefits from methods developed in the last thirty years in human epidemiology, it differs from human epidemiology by: the broad spectrum of animal species and its differences in longevity, pathology and genetics, the extend of control measures available and their direct effect on the epidemiology of the diseases, the priority of cost efficacy of disease control and epidemiological surveillance. The future of veterinary epidemiology lays in new areas, such as herd management and economics, genetic selection and molecular biochemistry, and geriatric epidemiology in pets.

Animal Diseases↗
PubMed1990

Inhibitory effects of 2'-fluorinated arabinosyl-pyrimidine nucleosides on woodchuck hepatitis virus replication in chronically infected woodchucks.

The treatment of woodchuck hepatitis virus infections with 1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)-5-iodocytosine (FIAC) and 1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)-5-methyluracil (FMAU), given intraperitoneally, caused complete and permanent decrease of serum virus endogenous DNA polymerase and viral DNA in all treated woodchucks but was associated with severe toxicity. By contrast 1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)-5-ethyluracil (FEAU) induced a sustained, although less dramatic, decrease of viral replication without apparent toxic effect. FEAU was also effective when given orally. However, in both cases this inhibitory effect was transient.

Administration, Oral↗
PubMed1987

The application of the ELISA technique to the serology of chlamydiosis in goats: statistical evaluation of a method.

The evaluation of the ELISA technique has been studied in the special case of its application to the serological diagnosis of chlamydiosis in goats. The results showed that this technique is reliable (accurate and reproducible) and efficient. Sera from 96 goats were studied with the ELISA technique, indirect immunofluorescence (IIF) and complement fixation (CF), the latter being the standard method in France. A comparison of the results revealed a similarity of findings with ELISA and indirect immunofluorescence and the greater sensitivity of the ELISA technique relative to that of complement fixation.

Animals↗
PubMed1986

Evidence for the presence of duck hepatitis B virus in wild migrating ducks.

A virus closely related to duck hepatitis B virus (DHBV) was isolated from serum and liver samples of wild migratory ducks (mallards) caught in two separate wildlife reserve parks in France. In the first one (Dombes region) 12% of wild mallards were positive for DHBV, and in the second (River Somme) 3% of mallards were found positive. The DHBV isolated from the serum of wild mallards was also associated with an endogenous DNA polymerase activity capable in vitro of completing a partially double-stranded viral DNA into a fully double-stranded DNA of 3 kb. The various replicative DNA forms reported for DHBV were also detected in the liver of wild viraemic mallards. The DNA restriction enzyme pattern of the wild mallard strain differed from that of American and French strains of DHBV. The wild mallard strain DHBV was experimentally transmitted to mallard and Pekin ducklings and induced a chronic viraemia in both varieties of infected birds. This strain might be the common ancestor of all DHBV strains isolated from domestic ducks world-wide. The discovery of a DHBV-related virus in the natural wild population might be an important clue in the study of the different roles of environmental, host and viral factors in the pathogenesis of DHBV infection, and their possible oncogenic action in ducks.

Animal Population Groups↗
PubMed1985

Comparative study of DHBV DNA levels and endogenous DNA polymerase activity in naturally infected ducklings in France.

Duck hepatitis B virus (DHBV) was found in the serum of 1-6% of Pekin ducklings originated from French commercial flocks. The viremia was followed in the serum of 5 ducklings over a span of 3 mth by monitoring the levels of DHBV DNA and the endogenous DNA polymerase (DNAp) activity. The DHBV DNA levels in serum were quantified either by the DNA dot hybridization technique including counting of retained radioactivity, or by successive dilutions of each serum sample followed by DNA hybridization. The counting of the retained radioactivity was plotted on a curve and its evolution compared with that of viral DNAp activity. DHBV DNA levels in serum, estimated by both methods paralleled those of the DNAp activity, which peaked at the 4th or 5th week posthatch to decrease and fluctuate thereafter. Occasional discordance between DHBV DNA levels and the endogenous DNAp activity was observed, which could be correlated with the degree of repair of the single stranded gap of serum DHBV DNA. Parallel follow up studies comparing quantitative estimations of serum viral DNA and of DNAp activity, as presented here, may provide some clues for the understanding of the mechanisms involved in the establishment of the HEPA DNA virus carrier state. Such comparative studies may also be crucial for optimal monitoring of antiviral drugs in both human clinical trials and animal experimental studies.

Animals↗
PubMed1984

[Spontaneous and experimental infection of alpine marmots (Marmota marmota) by the North American woodchuck hepatitis virus (Marmota monax). Initial results].

Summer's discovery in 1978 of a DNA virus, very close to human Hepatitis B virus in a woodchuck population in the U.S.A. (Pennsylvania) was a confirmation of the first description made by Snyder at Penrose Research Laboratory (Philadelphia). It was the first animal model of human B hepatitis infection. The comparative study of morphological, ecological and ethological characteristics of the marmot (Marmota marmota) and the woodchuck (Marmota monax) enables an easy distinction between these two species. The natural infection of M. monax by the WHV shows that the woodchuck is a good model for human B hepatitis and should be extended to M. marmota. A sample of 24 marmots caught in the Alpes of Haute-Provence has not revealed any spontaneous infection in these animals by the woodchuck virus. The failure of experimental inoculation of the marmot (24 animals) with the WHV confirms the refractory status of this species (no viremia and very low and short serological response with or without an immunosuppressive treatment). These preliminary results require a confirmation in other animals of different age and geographical region and also by using more specific tests such as molecular hybridization, research on DNA polymerase and direct transfection trials.

Age Factors↗
PubMedDate not supplied

Mass vaccination campaign against rabies: are dogs correctly protected? The Peruvian experience.

In a mass vaccination campaign conducted in Peru in March 1985, 270,000 dogs (65% of the estimated dog population) were vaccinated over the course of 1 month with an inactivated tissue culture vaccine. Since that time no human rabies cases have been reported; in addition, the number of animal rabies cases has declined to only three from a previous mean of 292 cases per year since 1980. A serologic survey was also done to determine the immune response among randomly selected vaccinated dogs, with titers determined 3, 6, 9, and 12 months after vaccination. Twelve months after vaccination, 97% of the dogs had a rabies neutralizing antibody titer of greater than or equal to 0.5 IU/mL, and 87% had a titer of greater than or equal to 1.0 IU/mL. Thus, this tissue culture rabies vaccine given under field conditions induced antibodies that lasted for at least 1 year in 97% of vaccinated dogs.

Animals↗