بررسي پلي مورفيسم لكوس هاي VNTR30و VNTR36 در سرووارهاي بيماري زاي لپتوسپيرا در ايران

Polymorphism Identification of VNTR30 and VNTR36 Loci in Pathogenic Leptospira Serovares in Iran

Abstract Background and objective: Leptospirosis, is the zoonotic disease which is characterized as an emerging infectious disease with large documented outbreaks. Epidemiological investigations are needed to distinguish outbreak situations or to trace reservoirs of the organisms. Today MLVA technique is used for segregating and identifying of Leptospira serovares. The method has potential application in furthering the understanding of Leptospiral molecular epidemiology. The propose of this study is rapid identification of pathogenic Leptospira serovares in Iran. Materials and methods: A total 12 pathogenic Leptospiral serovares and 1 saprophytic serovar that maintained from microbial bank of Razi Vaccine and Serum Research Institute, Karaj, Iran. The Genomic DNA of Leptospira was extracted .PCR was performed with primers for loci VNTR30, VNTR36. The amplified fragments were analyzed by gel electrophoresis . The sizes of the amplified products were estimated by comparison with a 100 -bp ladder. Results: All loci successfully amplified in all pathogenic leptospira serovars. The saprophytic serovar showed no amplified fragments. The results show VNTR30 has a wide range of polymorphism between Atumnalis, Hardjo St.Hardjo bovis, Pomona St. UT364, Icterohaemorrhagia St. RGA and VNTR36 shows variation between Canicola St. Hondutrecht IV , Hardjo St.Hardjo bovis, Pomona St. UT364 Conclusion: Most of the VNTR patterns were similar in different serovares while showed significant differences with same serovares of South America and Europe. On the other our serovares resemble Southeast Asia serovares because of the same geographical area. Among serovares Canicola St. Hondutrecht IV and Canicola St. Fiocruz LV133 identified by MLVA, PFGE was unable to differentiate them. In conclusion MLVA technique with wide range of polymorphism is known as good marker for identification serovares.