کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5801402 | 1555400 | 2011 | 5 صفحه PDF | دانلود رایگان |
Although serologic data indicate horses in N. America are exposed to a variety of leptospiral serovars, abortion is almost always associated with Leptospira interrogans serovar Pomona type kennewicki. A variety of wildlife including raccoons, white tailed deer, striped skunks, opossums, and red and grey foxes have been shown to host serovar Pomona and have therefore been suspect as sources of infection for pregnant mares. The aim of the present study was to examine genetic diversity in serovar Pomona type kennewicki in wildlife and in aborting mares. Our approach utilized PCR that targeted tandem repeats at the VNTR - 4 locus and a 1235Â bp 5â²-sequence of the lk73.5 (sph2) and adjacent upstream sequence unique to serovar Pomona. All isolates/specimens of equine origin in 1992 and 2008 yielded amplicons of 1235 and 595Â bp, whereas 14 isolates/specimens from wildlife yielding a 1235Â bp amplicon characteristic of serovar Pomona produced amplicons of 1300, 550Â bp (3), 1300Â bp (10), or 595Â bp (6) with the VNTR - 4 primer set. Wildlife therefore hosted at least three different genetic variants of type kennewicki including the genetic variant that predominated in aborting mares. The data are consistent with other studies indicating specific genetic variants of type kennewicki show a strong tendency to be associated with a specific host. Levels of antibody in wildlife sera reactive with rLk73.5, rLig130 and sonicate of type kennewicki were poorly correlated with PCR data, although rLk73.5 was superior to rLig130 in detection of antibody responses. PCR is therefore a more reliable tool for studies of wildlife reservoirs of Leptospira sp. than serologic surveillance that targets host induced proteins or LPS-rich sonicate.
Journal: Veterinary Microbiology - Volume 150, Issues 3â4, 2 June 2011, Pages 349-353