Characterisation of two novel species of Legionella isolated from tap water installations

The Genus Legionella encompass environmental bacteria frequently present in water samples. Two strains of Legionella isolated from tap water installations were identified as novel species. The genome of both strains was sequenzed and compared against a collection of genes from the Genus pan genome. Both strains codify for htpB, a heat shock moonlighting protein that act as an invasion virulence factor. The novel strains encoded antimicrobial resistance genes again beta-lactams and carbapenems, and presented an exclusive biofilm cluster of genes not present in other species of the Genus. The accessory annotation depicted clusters for terpene, siderophores, cyclodipeptide and polyaminoacids biosynthesis. These novel descriptions bring to light the pathogenic capacity of other species of Legionella not-pneumophila, the phylogenetic diversity of the Genus and their metabolic plasticity.

军团菌属（Legionella）包含常见栖息于水样中的环境细菌。本研究从自来水供水系统中分离得到两株军团菌，经鉴定为全新物种。研究人员对两株菌的基因组进行了测序，并与该属泛基因组（pan genome）的基因集合开展比对分析。结果显示，两株菌均编码htpB——一种兼具热休克功能的兼职蛋白，可作为侵袭性毒力因子。该新菌株携带针对β-内酰胺类与碳青霉烯类的抗菌药物耐药基因，同时拥有一套该属其他物种均未携带的生物膜相关基因簇。附属基因组注释结果表明，菌株存在萜类、铁载体、环二肽及聚氨基酸生物合成相关基因簇。本次研究的新发现，揭示了非嗜肺军团菌的致病潜力、军团菌属的系统发育多样性及其代谢可塑性。