铜绿假单胞菌是最常见的机会致病菌之一,由于其众所周知的多药耐药性和高毒力,导致严重的医院感染。对临床中遇到的流行性铜绿假单胞菌克隆进行常规管理是至关重要的。本研究的目的是研究流行克隆中毒力因子与抗菌素耐药性之间的联系。在这里,我们发现ST463(O4),ST1212(O11),和ST244(O5)在30个来自非囊性纤维化患者的分离株中普遍存在,基于多位点序列类型(MLST)和血清型分析。所有分离株均为多重耐药(MDR),并且在抗菌药物敏感性试验中,每种分离株对至少三类抗生素具有耐药性。这与丰富的抗性基因的存在是一致的,例如BlaOXA-50,BlaPAO,aph(3'),catB7,fosA,crpP,还有BLAKPC-2.值得注意的是,所有blaKPC-2基因均位于ISKpn6样和ISKpn8样移动遗传元件之间。此外,由exoU编码的经典外毒素,exoS,PLDA的含量为43.44%(13/40),83.33%(25/30),70%(21/30)的分离株,分别。编码典型毒素的phz操纵子的表达,绿脓苷,在60%的分离株(18/30)中观察到,并使用三重四极杆液相色谱质谱(LC/MS)测定法进行定量。有趣的是,与其他MLST类型相比,所有ST463分离株都有exoU,exoS和pldA,并产生范围为0.2至3.2μg/mL的绿脓苷。最后,我们使用溶血试验和Galleriamellonella幼虫感染模型评估了这些分离株的潜在毒性.结果表明,ST463分离株的毒力高于其他分离株。总之,产生绿脓素的ST463铜绿假单胞菌,携带不同的毒力基因,是一个潜在的高风险克隆。
Pseudomonas aeruginosa is one of the most common opportunistic pathogens, which causes severe nosocomial infections because of its well-known multidrug-resistance and hypervirulence. It is critical to curate routinely the epidemic P. aeruginosa clones encountered in the clinic. The aim of the present study was to investigate the connection between virulence factors and antimicrobial resistance profiles in epidemic clones. Herein, we found that ST463 (O4), ST1212 (O11), and ST244 (O5) were prevalent in 30 isolates derived from non-cystic fibrosis patients, based on multilocus sequence type (MLST) and serotype analysis. All isolates were multidrug-resistant (MDR) and each was resistance to at least three classes of antibiotics in antimicrobial susceptibility tests, which was consistent with the presence of the abundant resistance genes, such as bla OXA-50, bla PAO, aph(3\'), catB7, fosA, crpP, and bla KPC-2. Notably, all bla KPC-2 genes were located between ISKpn6-like and ISKpn8-like mobile genetic elements. In addition, classical exotoxins encoded by exoU, exoS, and pldA were present in 43.44% (13/40), 83.33% (25/30), and 70% (21/30) of the isolates, respectively. The expression of phz operons encoding the typical toxin,
pyocyanin, was observed in 60% of isolates (18/30) and was quantified using triple quadrupole liquid chromatograph mass (LC/MS) assays. Interestingly, compared with other MLST types, all ST463 isolates harbored exoU, exoS and pldA, and produced
pyocyanin ranging from 0.2 to 3.2 μg/mL. Finally, we evaluated the potential toxicity of these isolates using hemolysis tests and Galleria mellonella larvae infection models. The results showed that ST463 isolates were more virulent than other isolates. In conclusion,
pyocyanin-producing ST463 P. aeruginosa, carrying diverse virulence genes, is a potential high-risk clone.