Virulence Characterization of Dichelobacter nododsus from Clinical Cases of Ovine Footrot. In: IJVM - Vol. 72 No. 1, 2017
نویسنده
چکیده
ABST RACT Dichelobacter nodosus from ovine footrot was characterized for pgr and intA genes. Out of 260 samples collected from clinical cases of ovine footrot only 107 were found positive for D. nodosus by species-specific 16S r RNA-PCR. The overall prevalence of footrot based on clinical symptoms was estimated to be 10.57%. Serological diversity studies based on fimA gene revealed the presence of two serogroups of D. nodosus viz. B and E only. Out of 107 D. nodosus positive samples, 101(94.39%) were positive for serogroup B, while remaining six (5.60%) samples showed the presence of serogroup E. None of the samples revealed mixed infection with two or more serogroups. The samples positive for 16S rRNA were subjected to detection of the intA genes. A total of 67 (62.61%) samples were found to carry the intA gene. Since 63.36% of serogroup B positive samples and 50.00% of serogroup E positive samples carried intA gene, there appeared to be no bias towards either of the serogroups. Ten intA positive and 10 intA negative samples were randomly selected and subjected to detection of pgr genes. pgrA gene was present in all the intA positive and intA negative samples screened, suggesting no correlation between the occurrence of the intA gene and pgrA variants. However, pgr analysis appeared much more reliable than intA gene analysis for detection of virulent strains of D. nodosus. Considerable heterogeneity in pgrA variants offers significant potential as a molecular tool in future epidemiological studies.
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