Leptospira interrogans serogroup Sejroe serovar Hardjo in aborting cows: two herd cases in Sicily (Italy)

Introduction: The aim of this study was to present two outbreaks of bovine abortion due to Leptospira infection in cattle herds located in the northern part of Sicily (Italy). The animals were positive for Leptospira interrogans serogroup Sejroe serovar Hardjo in a microscopic agglutination test (MAT). Material and methods: A total of 23 Charolaise cows (farm A) and 75 Limousine bulls and Cinisara and Modicana cows (farm B) were enrolled in this study. The blood samples were collected from all subjects at the following time points: before a cycle of intramuscular treatment with oxytetracycline dihydrate (T0), after 5-6 weeks from the treatment (T1), and every 10 weeks until seronegativisation (T2 in Farm A and T3 in Farm B). A serological test (MAT) was used for the diagnosis of leptospirosis. Results: Two samples from farm A (2/23) and 29 samples from farm B (29/75) were positive to Leptospira interrogans, serogroup Sejroe, serovar Hardjo in the MAT. Leptospira spp. DNA was detected by real-time PCR in the urine sample of one positive cow on farm A, and in placenta and brain samples belonging to one aborted foetus on farm B. Conclusion: It is important to use serological and molecular diagnostic techniques complementarily to identify infected individuals.