Prevalence of Leptospira spp. In bovine aborted fetuses of dairy cattleherds by PCR in Tehran province

Leptospirosis is a zoonotic disease that can cause heavy economic losses through complications including abortion, stillbirth, infertility, reduced milk production, etc. In this study, 251 referred samples of aborted fetuses inindustrial dairy herds of Tehran province evaluated in MABNA laboratory during one year. Tested samples included a homogenous tissue mixture of fatal heart, kidney, liver and spleen. For DNA extraction, the ProteinaseK Method was used. Then polymerase chain reaction (PCR) was performed to recognize Leptospira Spp. by using specifc 16s rRNA gene primers. Samples with 331bp band in electrophoresis gel were considered positive.Prevalence of leptospiral abortion in average was 12.8 % in Tehran province during a year and based on season,respectively, the amount in spring was 15%, summer 9.08 %, autumn 10 % and winter 19.2 %. Based on theseresults, it was most prevalent in spring and winter that is probably due to higher environmental humidity, hydrophilic nature of leptospira and more bacterial activities. Generally according to the prevalence of 12.8 %, the majorcause of abortion in Tehran province in industrial dairy herds is leptospiral infection so that any activities in orderto eradicate and control the disease is essential.