Serodiagnosis and molecular survey on letospiral abortions from sheep farms in Tabriz and surrounding areas

Abstract

Leptospirosis is presumed to be the most widespread zoonosis in the world. The purpose of this study was to determine of seroprevalence of leptospirosis among the aborted ewes and in the same time, detection of bacterial DNA in aborted fetal tissues by the PCR protocol. A total number of 70 aborted fetuses and related placentas were submitted to the large animal clinic at the University of Tabriz, from October 2010 to March 2011.Tissue samples were collected from several fetal organs including liver, brain, kidney, lung, spleen, heart, stomach fluid and placenta, then separately pulverized under liquid nitrogen and finally stored at -20°C until DNA extraction. DNA extraction from frozen tissues samples was performed using a commercial kit (AccuPrep Genomic DNA Extraction Kit, Bioneer, S. Korea) following the manufacturer’s instructions. Of 70 submissions, 6(8/57%) samples were diagnosed positive to the leptospira Interrogans by the PCR. In contrast 7(10%) out of 76 dam’s sera were diagnosed as positive to leptospirosis by the microscopic agglutination test (MAT). One out of 70 animals was seropositive to serovar canicula, two animals to serovar pomona, two animals to grippotyphosa, one animal to serovars: grippotyphosa, pomona, hardjo and one animal to serovars: grippotyphosa, pomona, icterohaemorrhagiae. However, statistical difference was not observed between two diagnostic techniques (P≥0/05). In conclusion, both pomona and grippotyphosa serovars induced abortions were determined to be more common leptospiral abortions in sheep flocks in Tabriz (north-west of Iran).