Department of Biotechnology, Institute of Life Sciences, Nalco Square, Bhubaneswar 751023, India.
FEMS Microbiol Lett. 2021 Apr 22;368(6). doi: 10.1093/femsle/fnab035.
Classical Bordetella species are primarily isolated from animals and humans causing asymptomatic infection to lethal pneumonia. However, isolation of these bacteria from any extra-host environmental niche has not been reported so far. Here, we have characterized the genomic plasticity and antibody response of Bordetella bronchiseptica strain HT200, isolated from a thermal spring. Genomic ANI value and SNPs-based phylogenetic tree suggest a divergent evolution of strain HT200 from a human-adapted lineage of B. bronchiseptica. Growth and survivability assay showed strain HT200 retained viability for more than 5 weeks in the filter-sterilized spring water. In addition, genes or loci encoding the Bordetella virulence factors such as DNT, ACT and LPS O-antigen were absent in strain HT200, while genes encoding other virulence factors were highly divergent. Phenotypically, strain HT200 was non-hemolytic and showed weak hemagglutination activity, but was able to colonize in the respiratory organs of mice. Further, both infection and vaccination with strain HT200 induced protective antibody response in mouse against challenge infection with virulent B. bronchiseptica strain RB50. In addition, genome of strain HT200 (DSM 26023) showed presence of accessory genes and operons encoding predicted metabolic functions pertinent to the ecological conditions of the thermal spring.
经典博德特氏菌主要从动物和人类中分离出来，引起无症状感染到致命性肺炎。然而，到目前为止，还没有从任何其他宿主环境中分离到这些细菌的报道。在这里，我们对从温泉中分离到的支气管败血波氏杆菌 HT200 菌株的基因组可塑性和抗体反应进行了表征。基因组 ANI 值和 SNP 基于的系统发育树表明，HT200 菌株与人类适应的支气管败血波氏杆菌谱系发生了分歧进化。生长和存活试验表明，HT200 菌株在过滤消毒的温泉水中的存活时间超过 5 周。此外，HT200 菌株中不存在编码 DNT、ACT 和 LPS O-抗原等博德特氏菌毒力因子的基因或基因座，而编码其他毒力因子的基因高度分化。表型上，HT200 菌株不溶血，血凝活性较弱，但能够在小鼠的呼吸道中定植。此外，用 HT200 菌株感染和接种疫苗均可诱导小鼠产生针对强毒支气管败血波氏杆菌 RB50 菌株的保护性抗体反应。此外，HT200 菌株（DSM 26023）的基因组显示存在辅助基因和操纵子，它们编码与温泉生态条件相关的预测代谢功能。
