Ralstonia pickettii are ubiquitous in water environments. Members of this species are frequently, but not always, resistant to both gentamicin and arsenite. Gentamicin and arsenite co-resistance and the putative molecular mechanisms were investigated. A group of 37 R. pickettii strains isolated from drinking water and hospital wastewater were characterized for gentamicin and arsenite resistance phenotypes, the number and size of plasmids, and screened for genetic elements associated with arsenite tolerance, Integrative and Conjugative Elements (ICEs), among other. The genomes of three representative strains were compared.

Most gentamicin resistant (GR) isolates (32/33) were resistant to arsenite, and harbored ICE- and ars operon-related genes. These genetic elements were not detected in any of the five arsenite susceptible strains, regardless of the GR (n = 1) or gentamicin susceptibility (GS) (n = 4) phenotype. The comparison of the genomes of two GR (one resistant and one susceptible to arsenite) and one GS strains suggested that these phenotypes correspond to three phylogroups, distinguished by presence of some genes only in GR isolates, in addition to point mutations in functional genes. The presence of ICEs and ars operon-related genes suggest that arsenite resistance might have been acquired by GR lineages.

Ralstonia pickettii在水环境中无处不在。该物种的成员经常但并非总是对庆大霉素和亚砷酸盐具有抗性。研究了庆大霉素和亚砷酸盐的共抗性和假定的分子机制。从饮用水和医院废水中分离出的 37株R.pickettii菌株对庆大霉素和亚砷酸盐抗性表型、质粒的数量和大小进行了表征，并筛选了与亚砷酸盐耐受性、整合和结合元件 (ICE) 相关的遗传元件，其中包括其他。比较了三个代表性菌株的基因组。

大多数庆大霉素抗性 (GR) 分离株 (32/33) 对亚砷酸盐具有抗性，并含有 ICE 和ars操纵子相关基因。无论 GR (n = 1) 或庆大霉素易感性 (GS) (n = 4) 表型如何，在五种亚砷酸盐敏感菌株中的任何一种中均未检测到这些遗传元件。两种 GR（一种对亚砷酸盐具有抗性，一种对亚砷酸盐敏感）和一种 GS 菌株的基因组的比较表明，这些表型对应于三个系统群，除了功能基因中的点突变外，还通过仅在 GR 分离株中存在一些基因来区分。ICEs 和ars操纵子相关基因的存在表明亚砷酸盐抗性可能是由 GR 谱系获得的。