Immunity in heifers 12 months after vaccination with a multivalent vaccine containing a United States Leptospira borgpetersenii serovar Hardjo isolate.

Objective: To evaluate immunity induced by a multivalent vaccine containing a US Leptospira borgpetersenii serovar Hardjo type hardjo bovis (LHB) isolate in heifers challenged 12 months after vaccination.

Design: Prospective vaccine challenge study.

Animals: 36 one-month old Holstein heifers.

The induction of a cell-mediated immune response to bovine viral diarrhea virus with an adjuvanted inactivated vaccine.

This study evaluated the induction of bovine viral diarrhea virus (BVDV) cell-mediated and humoral immune responses after vaccination with an adjuvanted inactivated product. In vaccinated animals, there was an overall treatment effect (P less than .05), for an increased percentage of BVDV-specific CD8 T cells expressing interferon-γ (IFN-γ).

Patterns of antimicrobial resistance among commensal Escherichia coli isolated from integrated multi-site housing and worker cohorts of humans and swine.

We examined antimicrobial resistance (AR) phenotypes among commensal Escherichia coli isolated from fecal matter of humans and swine housed in a semi-closed and uniquely integrated multi-site farrow-to-plate operation. Aggregate cohorts of humans consisted of (1) "control" groups of consumers, (2) groups of swine workers, and (3) groups of slaughter-plant workers. Analyses of cross-sectional AR data from 472 human and 376 swine isolates are presented.

Spatial distribution of antibodies to Salmonella enterica serovar Typhimurium O antigens in bulk milk from Texas dairy herds.

Environmental factors that enhance either the survivability or dispersion of Salmonella enterica serovar Typhimurium (S. Typhimurium) could result in a spatial pattern of disease risk. The objectives of this study were to: (1) describe herd status based on antibody response to Salmonella Typhimurium as estimated from bulk tank milk samples and (2) to describe the resulting geographical patterns found among Texas dairy herds.

Prevalence of and risk factors for paratuberculosis in purebred beef cattle.

Objective: To estimate the prevalence of paratuberculosis in purebred beef cattle in Texas and identify risk factors for seropositivity.

Design: Epidemiologic survey.

Animals: 4,579 purebred cattle from 115 beef ranches in Texas.