Oligoadenylate synthetases play an important role in the immune response against dengue virus. Single nucleotide polymorphisms in the oligoadenylate synthetases genes are known to affect oligoadenylate synthetases activity and are associated with outcome of viral infections. Polymorphisms in the OAS1 SNPs (rs1131454), OAS2 SNPs (rs1293762, rs15895 and rs1732778) and OAS3 SNPs (rs2285932 and rs2072136) genes were studied using PCR followed by restriction fragment length polymorphism methods in 30 patients for dengue infection and 40 control group who have no documented evidence of symptomatic dengue. An increase in the frequency of OAS2 gene rs1293762 SNP G/T heterozygotes (p = 0.012), decrease in the frequency of SNP G/G homozygotes (p = 0.005) and decrease in the frequency of OAS2 gene rs1732778 SNP G/G homozygotes (p = 0.000017) and A/A homozygotes (p = 0.0000012) were observed among the dengue patients compared with control group. Our results suggest that OAS2 haplotypes are associated with differential susceptibility to clinical outcomes of dengue virus infection.

The main goal of this study was to evaluate the prevalence of leptospirosis among field rodents of Tiruchirappalli district, Tamil Nadu, India. In total 35 field rats were trapped and tested for seroprevalence by the microscopic agglutination test (MAT). Isolation of leptospires was performed from blood and kidney tissues and characterized to serovar level. Genomospecies identification was carried out using 16S rRNA and lipL32 gene sequencing. The molecular phylogeny was constructed to find out species segregation. Seroprevalence was about 51.4 %, and the predominant serovars were Autumnalis, Javanica, Icterohaemorrhagiae and Pomona. Two isolates from the kidneys were identified as serovar Javanica of Serogroup Javanica, and sequence based molecular phylogeny indicated these two isolates were Leptospira borgpetersenii.