Classification of Yersinia pestis biovars through pangenome analysis

Authors

Affiliation

Kiran Paranjape

Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden

Yumeng Wang

Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden

Lionel Guy

Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden

Helen Wang

Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden

Abstract

Yersinia pestis is the causative agent of the plague, a very serious and fatal disease. The disease is zoonotic and transmitted by fleas carrying the bacterium. Over the past millennia, three major outbreaks of plague have occurred, killing more than an estimated 500 million people. These outbreaks allowed the bacterium to spread across the world and have been the basis for typing strains of Y. pestis. Strains are usually typed according to their biovar, which is reliant on biochemical tests. Though these tests are easy to perform, they lack the discriminatory power to distinguish different strains. Here we evaluated the pangenome of several strains from China, and strains from the NCBI RefSeq database. The results showed that the genomes of these strains were quite diverse in their gene content. This is contrary to what was expected as Y. pestis is highly clonal, and thus the diversity of its pangenome would mainly be due to mutation rate and not recombination. Consequently, the pangenome could be an opportunity to identify new genes for typing methods to increase discriminatory power between Y. pestis strains, giving epidemiologist better insights into outbreaks of plague.