Laboratorio de Investigación en Agentes Antibacterianos (LIAA), Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile; Grupo de Estudio en Resistencia Antimicrobiana (GRAM), Universidad de Concepción, Concepción, Chile.
Programa de Genómica Evolutiva, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, México.
J Glob Antimicrob Resist. 2024 Sep;38:205-211. doi: 10.1016/j.jgar.2024.05.015. Epub 2024 Jun 5.
Carbapenem-resistant Pseudomonas aeruginosa (CRPA) is a serious threat to public health. Globally, carbapenemases-producing CRPA isolates mainly belong to 'high-risk' clones; however, the molecular epidemiology of CRPA isolates circulating in Chile are scarce, where this pathogen is the main aetiological agent of ventilator-associated pneumonia.
To characterize the phylogenomics and molecular features of ST654 CRPA isolates collected in Chile between 2016 and 2022.
Eighty-nine CRPA isolates collected in different Chilean hospitals from clinical specimens between 2005 and 2022 were analysed. Antibiotic susceptibility tests and carbapenemases production were carried out on the CRPA ST654 isolates. Also, they were subjected to whole-genome sequencing, from which in silico analyses were performed.
Thirty-four strains (38.2%) belonged to the ST654 high-risk clone, being the most predominant lineage of the collection. Most of these isolates belonged to a subclade including KPC producers that also clustered with strains from Argentina and the United States, whereas few VIM and NDM co-producers clustered in two different smaller subclades. The isolates exhibited a broad resistome encompassing genes mediating resistance to several other clinically relevant drugs. Additionally, all the 34 ST654 isolates were ExoS+ as a virulence factor and associated to the O4-serotype.
Our report represents the most comprehensive phylogenomic study of a CRPA high-risk clone ST654 to date. Our analyses suggest that this lineage is undergoing a divergent evolutionary path in Chile, because most of the isolates were KPC producers and were O4 serotype, differing from previous descriptions, which underline the relevance of performing molecular surveillance on this pathogen.
耐碳青霉烯铜绿假单胞菌（CRPA）是对公共卫生的严重威胁。在全球范围内，产碳青霉烯酶的 CRPA 分离株主要属于“高风险”克隆；然而，在智利流行的 CRPA 分离株的分子流行病学尚不清楚，而这种病原体是呼吸机相关性肺炎的主要病原体。
描述 2016 年至 2022 年期间在智利收集的 ST654 型 CRPA 分离株的系统发生基因组学和分子特征。
分析了 2005 年至 2022 年期间从智利不同医院的临床标本中收集的 89 株 CRPA 分离株。对 CRPA ST654 分离株进行抗生素敏感性试验和碳青霉烯酶产生试验。此外，对它们进行了全基因组测序，并进行了计算机分析。
34 株（38.2%）属于高风险克隆 ST654，是该分离株的主要谱系。这些分离株大多属于一个亚群，包括 KPC 生产者，这些分离株与来自阿根廷和美国的菌株聚类，而少数 VIM 和 NDM 共生产者聚类在两个不同的较小亚群中。这些分离株表现出广泛的耐药性，包括介导对几种其他临床相关药物耐药的基因。此外，34 株 ST654 分离株均为 ExoS+作为毒力因子，并与 O4 血清型相关。
本报告代表了迄今为止对 CRPA 高风险克隆 ST654 的最全面的系统发生基因组学研究。我们的分析表明，该谱系在智利正在经历一个不同的进化途径，因为大多数分离株是 KPC 生产者，并且是 O4 血清型，与以前的描述不同，这强调了对这种病原体进行分子监测的重要性。
