P SCHNYDRIG¹, S VIDAL¹, V PERRETEN¹, S RODRIGUEZ-CAMPOS<sup>1

1</sup>Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Switzerland

Leptospira are flexible, spiral-shaped, Gram-negative spirochaete bacteria that cause leptospirosis in a wide range of mammals, including sheep (Ovis aries) and goats (Capra aegagrus hircus). Leptospirosis is characterized in small ruminants by abortions, neonatal deaths and impaired fertility. The gold standard for the diagnosis of leptospirosis is the microscopic agglutination test (MAT) based on detection of antibodies in serum. Real time PCR is also often used to directly detect leptospiral DNA. Between 1991 and 2015, 485 cases of leptospirosis in cattle were notified, however only one case of leptospirosis was reported in small ruminants. In order to better evaluate the importance of this possible abortive agent in small ruminants, we screened 79 tissue samples [placenta (n=50); abomasum (n=29)] corresponding to 61 cases [sheep (n=31); goat (n=30)] from 2012-2016 for presence of pathogenic Leptospira spp. by real time PCR and 27 related serum samples from ewes by MAT. The MAT was performed with a panel of 9 serovars [Grippotyphosa, Australis, Pomona, Tarassovi, Canicola, Icterohaemorrhagiae, Hardjo, Sejroe, Ballum]. The titers of the serum samples were determined from 1:100 to 1:3200. The bacterial DNA was extracted from abortion material with QIAamp Mini Kit (Qiagen) [samples (n=51)] and with Ultra Clean® Tissue&Cells DNA Isolation Kit (MoBio) [samples (n=28)]. Real time PCR was performed in a 7500 Real Time PCR System (Applied Biosystems), targeting the gene coding for the outer membrane protein LipL32. Out of the 27 sera tested by MAT, 8 sera [sheep (n=6); goat (n=2)] were seropositive for one serovar [Australis (n=2), Pomona (n=2), Hardjo (n=2), Ballum (n=2)] and one serum [sheep (n=1)] was positive for two serovars [Sejroe (n=1), Hardjo (n=1)]. From the 79 tissue samples analyzed by real time PCR, 3 samples [placenta (n=2); abomasum (n=1)] from sheep were positive. One of the PCR positive cases was negative in the MAT. These results indicate that even if leptospirosis plays a minor role in abortion in small ruminants, sporadic cases can occur.