Aeromonas hydrophila RIT668 and Citrobacter freundii RIT669 were isolated from endangered spotted turtles (Clemmys guttata). Whole-genome sequencing, annotation and phylogenetic analyses of the genomes revealed that the closest relative of RIT668 is A. hydrophila ATCC 7966 and Citrobacter portucalensis A60 for RIT669. Resistome analysis showed that A. hydrophila and C. freundii harbor six and 19 different antibiotic resistance genes, respectively. Both bacteria colonize polyethylene and polypropylene, which are common plastics, found in the environment and are used to fabricate medical devices. The expression of six biofilm-related genes—biofilm peroxide resistance protein (bsmA), biofilm formation regulatory protein subunit R (bssR), biofilm formation regulatory protein subunit S (bssS), biofilm formation regulator (hmsP), toxin-antitoxin biofilm protein (tabA) and transcriptional activator of curli operon (csgD)—and two virulence factors—Vi antigen-related gene (viaB) and Shiga-like toxin (slt-II)—was investigated by RT-PCR. A. hydrophila displayed a > 2-fold increase in slt-II expression in cells adhering to both polymers, C. freundii adhering on polyethylene displayed a > 2-fold, and on polypropylene a > 6-fold upregulation of slt-II. Thus, the two new isolates are potential pathogens owing to their drug resistance, surface colonization and upregulation of a slt-II-type diarrheal toxin on polymer surfaces.

中文翻译：

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从两个濒危乌龟（Clemmys guttata）中分离出来的两种耐多药细菌，嗜水气单胞菌RIT668和弗氏柠檬酸杆菌RIT669在塑料定居过程中表达了志贺样毒素。

从濒临灭绝的斑点海龟（Clemmys guttata）中分离出嗜水气单胞菌RIT668和弗氏柠檬酸杆菌RIT669 。全基因组测序，注释和基因组的系统发育分析表明，RIT668的最接近相对是嗜水ATCC 7966和柠檬酸杆菌portucalensis A60为RIT669。Resistome分析表明，嗜水和弗氏柠檬酸杆菌分别具有六个和19个不同的抗生素抗性基因。细菌都会在环境中发现的聚乙烯和聚丙烯（它们是常见的塑料）上定居，并被用于制造医疗设备。六个生物膜相关基因的表达-生物膜过氧化物抗性蛋白（bsmA），生物膜形成调节蛋白亚基R（bssR），生物膜形成调节蛋白亚基S（bssS），生物膜形成调节剂（hmsP），毒素-抗毒素生物膜蛋白（ tabA）和curli操纵子（csgD）的转录激活因子以及两个毒力因子-Vi抗原相关基因（viaB）和志贺样毒素（slt - II）-通过RT-PCR研究。嗜水气单显示在> 2倍的增加SLT-II在细胞附着于两种聚合物的表达，弗氏柠檬酸杆菌附着在聚乙烯上显示的> 2倍，并且在聚丙烯>的6倍上调SLT-II。因此，这两种新分离株由于它们的耐药性，表面定植和聚合物表面上的slt-II型腹泻毒素的上调而成为潜在的病原体。