Cloning and Sequencing of Gene Encoding Outer Membrane Lipoprotein LipL41 of Leptospira Interrogans Serovar Grippotyphosa

Leptospirosis is an infectious bacterial disease caused by pathogenic serovars of Leptospira. Development of reliable and applicable diagnostic test and also recombinant vaccine for this disease require specific antigens that are highly conserved among diverse pathogenic leptospiral serovars. Outer membrane proteins(OMPs) of leptospira are effective antigens which can stimulate remarkable immune responses during infection, among them LipL41 is an immunogenic lipoprotein which is present only in pathogenic serovars so it could be regarded as a good candidate for vaccine development and diagnostic method. In order to identify genetic conservation of the lipL41 gene, we cloned and sequenced this gen from Leptospira interrogans serovar vaccinal and field of Grippotyphosa. Leptospira interrogans serovar vaccinal Grippotyphosa (RTCC2808) and serovar field Grippotyphosa (RTCC2825)were used to inoculate into the selective culture medium(EMJH). The genomic DNA was extracted by standard phenol-chloroform method. The lipL41 gene were amplified by specific primers and cloned into pTZ57R/T vector and transformed into the competent E. coli (Top10) cells. the extracted recombinant plasmid were sequenced. And the related sequences were subjected to homology analysis by comparing them to sequences in the Genbank database. PCR amplification of the lipL41 gene resulted in the 1065 bp PCR product. DNA sequence analysis revealed that lipL41 gene between serovar vaccinal Grippotyphosa (RTCC2808)and serovar field Grippotyphosa (RTCC2825) in Iran was 100%. It was also showed that the lipL41 gene had high identity (96%-100%) with other pathogenic serovars submitted in Genbank database. The results of this study showed that the lipL41 gene was highly conserved among various pathogenic Leptospira serovars(>95.9 % identity). Hence the cloned gene could be further used for expression of recombinant protein for serodiagnosis and also can be a good candidate for vaccine against leptospirosis.