Comparative genome characterization of Leptospira interrogans from mild and severe leptospirosis patients using Next-generation sequencing data

Leptospirosis is a zoonotic disease, caused by spirochetes from the genus Leptospira. In Thailand, Leptospira interrogans is a major cause of leptospirosis. Leptospirosis patients present with the wide range of clinical manifestations from asymptomatic, mild infections to severe illness involving organ failures. For better understanding the difference between Leptopira isolates causing mild and severe leptospirosis, illumina sequencing was used to sequence genomic DNA in both serotype. DNA of Leptospira isolated from 2 patietns, one with mild and another with severe symptoms, were inlcuded in this study. The paired-end reads were removed adapters and trimmed with Q30 score using Trimmomatic. Trimmed reads were constructed to contigs and scaffolds using Spades. Cross-contamination of scaffolds was evaluated by ContEst16s. Prokka tool for bacterial annotation was used to annotate sequences from both Leptospira isolates. Predicted amino acid sequences from Prokka were searched to EggNOG and David gene ontology database for finding gene ontology. In addition, Leptospira from mild and severe patients annotated that passed the criteria e-value < 10e-5 from blastp against virulence factor database were used to analysis with venn diagram. From this study, we found 13 and 12 genes that unique in the isolates from mild and severe patietns, respectively. The 12 genes in the severe isolate might be virulence factor genes that affect disease severity. However, these genes should be validated in further study.