Application of multiple-locus variable-number tandem repeat analysis(MLVA) for molecular typing of Leptospira interrogans serogroup Icterohaemorrhagiae

Abstract

Objective To establish the method of multiple loci VNTR(variable numbers tandem-repeats) analysis (MLVA) for genotyping Leptospira interrogans serogroup ieterohaemorrhagiae . Methods Seven VNTR loci were chosen for genotyping 117 strains of L. interrogans serogroup Icterohaemorrhagiae by PCR-electrophoresis-based VNTR analysis and the results were analyzed by software BioNumerics( Version 4.0). Results One hundred and seventeen isolates of L. interrogans serogroup Icterohaemorrhagiae detec-ted with 7 VNTR loci were classified into three clusters(A,B,C), twenty-eight types were found, type A 11.97% (14/117), type B 0.85% (1/1 17), type C 87.18% (102/117). Diversity Indexes for the loci varied between 0.0831 and 0.8005. Clinical strains isolated from the same geographic area and belonging to the same serogroup shared a common VNTR pattern. Conclusion MLVA could be used to classify and identify Leptospira interrogans preliminarily. With the improvement of technology, this rapid and easy method should greatly contribute to a better knowledge of the epidemiology of Leptospira. Key words: Leptospira interrogate; Serogroup Icterohaemorrhagiae; Genotyping; MLVA