Genetic diversity of Bacillus anthracis Ames lineage strains in China

Abstract

Background: Anthrax is an endemic disease that persists in the rural regions of China. The global genetic population structure of B.anthracis has also been defined by the canonical single-nucleotide polymorphisms (canSNP) and multiple-locus variable-number tandem repeat analysis (MLVA). Five canSNP lineages were found in China, and the A.Br.Ames lineage has been the second predominant group in recent years in China. The objective of this study was to reveal genetic diversity of the Ames lineage strains by MLVA. Methods: Two molecular typing methods, canSNP and MLVA with 15markers were used to study the genetic relationship among the Ames lineage strains. The outbreak information associated with these strains was also collected and investigated. Results: From 2007 to 2018, a total of 21 human anthrax infection outbreaks (68 patients) associated with B. anthracis Ames lineage strains were reported in China. Ames lineage strain-associated human anthrax is mainly distributed in the northern part of China, including the provinces of Inner Mongolia, Liaoning, Gansu, and Xinjiang. In the study, a total of 30 Ames lineage strains were included and 10 MLVA15 genotypes were identified. These strains were mainly found in northeast China, Inner Mongolia and Liaoning. In recent years, the Ames lineage strains were isolated in the two provinces every year. The 18 Ames lineage strains isolated from Inner Mongolia were divided into eight MLVA15 genotypes. From 2010 to 2015, there were continuous reports of outbreaks in Keyouzhongqi County, Inner Mongolia, and the strains that were isolated annually in succession belonged to the MLVA15-30 genotype. Conclusions: The Ames lineage strains are widely distributed in northern China. Their genetic diversity can be illustrated by the results of the MLVA. The genetic characteristics of the Ames lineage strains from outbreaks in different provinces varied. In some areas, human anthrax outbreaks occurred annually in succession, and these related strains grouped together. These observations indicate that the local environment was persistently contaminated with B. anthracis spores, vaccination of livestock should become the fundamental control measure in the areas.

Development of a methodology for molecular genetic monitoring for the cholera causative agent

“…На наш взгляд, это делает актуальным разработку методик, основанных на использовании единого перечня SNP, что позволит повысить оперативность проведения анализа при выделении свежих штаммов. Стоит отметить, что подобный подход, предусматривающий анализ по заранее определённому перечню SNP, уже с успехом реализован для возбудителя сибирской язвы [13][14][15] и туляремии [16,17].…”

The roles of antimicrobial resistance, phage diversity, isolation source and selection in shaping the genomic architecture of Bacillus anthracis

“…Individual and regional genetic diversity that differentiates B. anthracis populations by SNP architecture has been identified on a global scale [23–26]. Recent work has refined our understanding of population genomic structure for this species [27, 28].…”