Servicio de Microbiología and Unidad de Investigación, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma (IdISPa), Ctra. Valldemossa 79, 07010 Palma de Mallorca, Spain.
Servicio de Microbiología and Unidad de Investigación, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma (IdISPa), Ctra. Valldemossa 79, 07010 Palma de Mallorca, Spain.
Drug Resist Updat. 2015 Jul-Aug;21-22:41-59. doi: 10.1016/j.drup.2015.08.002. Epub 2015 Aug 10.
The increasing prevalence of chronic and hospital-acquired infections produced by multidrug-resistant (MDR) or extensively drug-resistant (XDR) Pseudomonas aeruginosa strains is associated with significant morbidity and mortality. This growing threat results from the extraordinary capacity of this pathogen for developing resistance through chromosomal mutations and from the increasing prevalence of transferable resistance determinants, particularly those encoding carbapenemases or extended-spectrum β-lactamases (ESBLs). P. aeruginosa has a nonclonal epidemic population structure, composed of a limited number of widespread clones which are selected from a background of a large quantity of rare and unrelated genotypes that are recombining at high frequency. Indeed, recent concerning reports have provided evidence of the existence of MDR/XDR global clones, denominated high-risk clones, disseminated in hospitals worldwide; ST235, ST111, and ST175 are likely those more widespread. Noteworthy, the vast majority of infections by MDR, and specially XDR, strains are produced by these and few other clones worldwide. Moreover, the association of high-risk clones, particularly ST235, with transferable resistance is overwhelming; nearly 100 different horizontally-acquired resistance elements and up to 39 different acquired β-lactamases have been reported so far among ST235 isolates. Likewise, MDR internationally-disseminated epidemic strains, such as the Liverpool Epidemic Strain (LES, ST146), have been noted as well among cystic fibrosis patients. Here we review the population structure, epidemiology, antimicrobial resistance mechanisms and virulence of the P. aeruginosa high-risk clones. The phenotypic and genetic factors potentially driving the success of high-risk clones, the aspects related to their detection in the clinical microbiology laboratory and the implications for infection control and public health are also discussed.
耐多药（MDR）或广泛耐药（XDR）铜绿假单胞菌菌株引起的慢性和医院获得性感染的患病率不断增加，与显著的发病率和死亡率相关。这种日益严重的威胁是由于该病原体通过染色体突变产生耐药性的非凡能力，以及可转移耐药决定因素（特别是那些编码碳青霉烯酶或扩展谱β-内酰胺酶（ESBLs）的决定因素）的流行率增加所致。铜绿假单胞菌具有非克隆流行人群结构，由少数广泛克隆组成，这些克隆是从大量稀有且不相关的基因型背景中选择出来的，这些基因型以高频率重组。事实上，最近令人担忧的报告提供了证据，证明存在 MDR/XDR 全球克隆，称为高风险克隆，在全球医院中传播；ST235、ST111 和 ST175 可能是更广泛的克隆。值得注意的是，全球绝大多数 MDR，特别是 XDR 菌株的感染都是由这些和少数其他克隆引起的。此外，高风险克隆（特别是 ST235）与可转移耐药性的关联是压倒性的；迄今为止，在 ST235 分离株中已报道了近 100 种不同的水平获得性耐药元件和多达 39 种不同的获得性β-内酰胺酶。同样，在囊性纤维化患者中也注意到了具有国际传播性的流行菌株，如利物浦流行株（LES，ST146）。在这里，我们综述了高风险铜绿假单胞菌克隆的种群结构、流行病学、抗菌药物耐药机制和毒力。还讨论了推动高风险克隆成功的表型和遗传因素、在临床微生物学实验室中检测它们的相关方面，以及对感染控制和公共卫生的影响。
