Publications

The regulation and control of gene expression in response to differing environmental stimuli is crucial for successful pathogen adaptation and persistence. The regulatory gene vru of Streptococcus uberis encodes a stand-alone response regulator with similarity to the Mga of group A Streptococcus. Mga controls expression of a number of important virulence determinants. Experimental intramammary challenge of dairy cattle with a mutant of S. uberis carrying an inactivating lesion in vru showed reduced ability to colonize the mammary gland and an inability to induce clinical signs of mastitis compared with the wild-type strain. Analysis of transcriptional differences of gene expression in the mutant, determined by microarray analysis, identified a number of coding sequences with altered expression in the absence of Vru. These consisted of known and putative virulence determinants, including Lbp (Sub0145), SclB (Sub1095), PauA (Sub1785) and hasA (Sub1696).

Major histocompatibility complex (MHC) genes play a key role in immunity to infectious pathogens. Their high level of diversity is a functionally important characteristic. In cattle our knowledge of MHC diversity and the functional distinction between genes is limited. Recent studies in commercially important dairy cattle populations reveal that MHC class I diversity is relatively low, although it does not appear to be declining. The presence and frequency of some genes and alleles was markedly different between geographically distinct populations, and trait selection was implicated as an influential force. Functional studies suggest that some alleles may have a disproportionally high impact on T cell responses, thus it may be important to consider their role in both disease resistance and vaccine efficacy. It is clear that increasing our knowledge of the functional capabilities of different cattle MHC class I genes is essential to maintain healthy populations in the future.

Two lateral flow devices (LFD) for the detection of vesicular stomatitis (VS) virus (VSV), types Indiana (VSV-IND) and New Jersey (VSV-NJ) were developed using monoclonal antibodies Cl and F25VSVNJ-45 to the respective VSV serotypes. The performance of the LFDs was evaluated in the laboratory on suspensions of vesicular epithelia and cell culture passage derived supernatants of VSV. The collection of test samples included 105 positive for VSV-IND (92 vesicular epithelial suspensions and 13 cell culture antigens; encompassing 93 samples of subtype 1 [VSV-IND-1],9 of subtype 2 [VSV-IND-2] and 3 of subtype 3 [VSV-IND-3]) and 189 positive for VSV-NJ (162 vesicular epithelial suspensions and 27 cell culture antigens) from suspected cases of vesicular disease in cattle and horses collected from 11 countries between 1937 and 2008 or else were derived from experimental infection and 777 samples that were either shown to be positive or negative for foot-and-mouth disease (FMD) virus (FMDV) and swine vesicular disease virus (SVDV) or else collected from healthy cattle or pigs and collected from 68 countries between 1965 and 2011. The diagnostic sensitivity of the VSV-IND (for reaction with VSV-IND-1) and VSV-NJ LFDs was either similar or identical at 94.6% (VSV-IND) and 97.4% (VSV-NJ) compared to 92.5% and 97.4% obtained by the reference method of antigen ELISA. The VSV-IND LFD failed to react with viruses of VSV-IND-2 and 3, while the VSV-NJ device recognized all VSV-NJ virus strains. The diagnostic specificities of the VSV-IND and VSV-NJ LFDs were 99.1% and 100, respectively, compared to 99.6% and 99.8% for the ELISA. Reactions with FMDV which can produce indistinguishable syndromes clinically in cattle, pigs and sheep and SVDV (vesicular disease in pigs) did not occur. These data illustrate the potential for the LFDs to be used next to the animal for providing rapid and objective support to veterinarians in their clinical judgment of vesicular disease and for the subtype (VSV-IND-1) and type-specific (VSV-NJ) pen-side diagnosis of VS and differential diagnosis from FMD.

This study describes a comparison of the efficacy of the Monty Roberts horsemanship technique (MRT) in comparison with a UK conventional training technique (CT) for the initial training of horses. The sample consisted of 14 untrained horses, between 3 and 5 years old, sourced from a variety of non-competition yards in the UK. Horses were matched on temperament and randomly assigned to either the MRT group or the CT group. Each trainer was allowed 30 minutes per day to work with each horse for 20 days, following which the horses undertook a standardized ridden obstacle and flatwork test and a ridden freestyle test. Horses were scored for technical performance by a panel of judges who were unaware of the study or the trainers involved. During the session where the first saddle and rider were achieved, MRT-trained horses had significantly lower (p = 0.0137) maximum heart rates (bpm ± SD) (first saddle: 127 ± 37, first rider: 76 ± 12) when compared with CT-trained horses (first saddle: 176 ± 24, first rider: 147 ± 61). MRT-trained horses had similar mean heart rates to CT-trained horses (91 ± 15 bpm, 80 ± 7 bpm, respectively) during the ridden obstacle test but received significantly higher performance scores from the judges (171 ± 4, 133 ± 7, respectively; p