INVESTIGATION OF MURINE RODENTS FOR THE PRESENCE OF LEPTOSPIRA DNA BY NESTED PCR

Leptospirosis is a zooanthroponosis with natural foci. People become infected with leptospires either directly from host animals or by means of certain elements of the external environment. Circulation of leptospires in nature is maintained by reservoirs and supporting hosts. For the first time in Bulgaria we applied nested PCR in examining organs of murine rodents for the presence of Leptospira spp. DNA. A total of 109 rodents were investigated after being collected from 4 districts in Southern Bulgaria: Plovdiv, Pazardzhik, Smolyan and Blagoevgrad. The genome of Leptospira spp. was found in 5 species of rodents. Results show that Microtus spp. is a potential carrier of leptospires, especially in urban areas. The high rate of leptospiral DNA-positive rodents captured in the region of Pazardzhik confirms the activity of the epizootic process in this natural focus, where epidemics of benign leptospirosis have been recorded in the past. The introduced method would help to clarify the epidemiological links more quickly in case of a leptospirosis outbreak in some regions. Stronger measures are needed to combat rats, murine rodents and their entry in warehouses, slaughterhouses and mass caterers, in order to maintain the cleanliness of open-air ponds, water sources and prevent contamination of food products. Future studies in this area would enrich the knowledge on the circulation of leptospires in their reservoirs in more areas of our country.