Experimental Coxiella burnetii infection in pregnant goats: excretion routes.

Q fever is a widespread zoonosis caused by Coxiella burnetii. Infected animals, shedding bacteria by different routes, constitute contamination sources for humans and the environment. To study Coxiella excretion, pregnant goats were inoculated by the subcutaneous route in a site localized just in front of the shoulder at 90 days of gestation with 3 doses of bacteria (10(8), 10(6) or 10(4) i.

Relationships between the shedding of Coxiella burnetii, clinical signs and serological responses of 34 sheep.

Two abortions associated with Coxiella burnetii occurred in a group of 34 pregnant ewes. The seroprevalence of C. burnetii infection was studied by using an ELISA and the immunofluorescence (IF) assay was applied to the contents of vaginal swabs.

Differences in frequency, level, and duration of cecal carriage between four outbred chicken lines infected orally with Salmonella enteritidis.

Four chicken lines, L2, B13, PA12 (egg-type), and Y11 (meat-type), were tested for experimental carrier state of Salmonella enteritidis (SE) in two identical trials. After oral inoculation of SE at 1 wk of age with 5 x 10(4) SE colony-forming units (CFU), 10 chickens per line were necropsied weekly for 6 wk and then every 8 or 15 days until the 12th week postinoculation (PI). Liver, spleen, ovary, and ceca were examined for level of SE colonization.

Quantification of experimental Salmonella enteritidis carrier state in B13 leghorn chicks.

Quantification of the carrier state of Salmonella enteritidis in chicks (i.e., persistent asymptomatic association of S.

Comparison of the efficacy of Brucella suis strain 2 and Brucella melitensis Rev. 1 live vaccines against a Brucella melitensis experimental infection in pregnant ewes.

The comparative efficacy of Brucella suis strain 2 (S2) and Brucella melitensis strain Rev. 1 (Rev. 1) live vaccines in protecting sheep against B.

Restriction fragment length polymorphism of DQB and DRB class II genes of the ovine major histocompatibility complex.

The ovine major histocompatibility complex (MhcOvar) class II region was investigated by Southern blot hybridizations using ovine probes specific for the second exons of Ovar-DRB and Ovar-DQB genes. Multiple bands were revealed when genomic DNA was digested with each of five restriction enzymes (BamHI, EcoRI, HindIII, PvuII and TaqI), and successively hybridized with the two radiolabelled ovine probes. Restriction fragment length polymorphisms (RFLPs) were analysed in 89 sheep originating from six inbred families and the inheritance of the fragment patterns was determined.

Genetic control of resistance to enterotoxigenic Escherichia coli in infant mice.

DBA/2 and CBA infant mice orally challenged with bovine enterotoxigenic Escherichia coli (ETEC) strain B80 presented resistance and susceptibility respectively, as measured by mortality rates 6 days after inoculation. Serum antibodies agglutinating ETEC strain B80 had very low titers in both mouse strains. Mendelian analysis of resistance on F1 and on segregating back-crosses showed that resistance is genetic and dominant.

[Experimental paratuberculosis: biological diagnosis in calves inoculated with strains of mycobactin-dependent mycobacteria].

During an experiment on the pathogenicity of mycobactin-dependent mycobacteria strains for calf, the kinetics of antibody formation during infection was studied. The progress of cellular immunity was followed by examining delayed hypersensitivity using four allergens (bovine tuberculin HCSM, avian tuberculin HCSM, avian tuberculin PPD, and johnin PPD), and that of humoral immunity using complement fixation test and ELISA. Simultaneously, the elimination of bacilli in the faeces was examined.

[Experimental paratuberculosis: pathogenicity of mycobactin-dependent mycobacteria strains to calves].

The pathogenicity for calves of two strains of wood-pigeon mycobacteria isolated in our laboratory, one strain isolated in the United Kingdom, one strain isolated from a Roe-deer in Denmark and three strains of M. paratuberculosis, were compared. Seven groups of four 3 to 4 week-old calves were infected by the intravenous route using 10(6) to 10(9) viable units.