One of the most significant organisms producing leptospirosis is Leptospira interrogans serogroup Canicola, which is utilised as a vaccine strain in the current Chinese human leptospirosis vaccine. L. interrogans serogroup Canicola vaccine strain 611 and circulating isolate LJ178 from different hosts at different times were sequenced using a combined strategy of Illumina X10 and PacBio technologies, and a comprehensive comparative analysis with other published Leptospira strains was performed in this study. There were significant genetic similarities between vaccination strain 611 and circulating isolate LJ178; both contained two circular chromosomes and two circular extrachromosomal replicons.
In comparison to the strain 611 genome, strain LJ178 has 132 single nucleotide polymorphisms and 92 indels. In both genomes, the bigger lipopolysaccharide biosynthesis gene of serogroup Canicola was found. Based on whole-genome sequences, phylogenetic analysis indicated that serogroup Canicola was not confined to a single host or geographic region, implying adaptive evolution linked with ecological variety. In conclusion, the findings contribute to a deeper molecular knowledge of the component strains of China’s human leptospirosis vaccine. These findings describe the genetic makeup and evolutionary relationships of Leptospira strains that represent a health risk.
Reference: https://www.tandfonline.com/doi/full/10.1080/21645515.2020.1720439
