Furlan João Pedro Rueda, Ramos Micaela Santana, Rosa Rafael da Silva, Dos Santos Lucas David Rodrigues, Savazzi Eduardo Angelino, Stehling Eliana Guedes
Department of Clinical Analyses, Toxicology and Food Science, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Brazil.
Department of Clinical Analyses, Toxicology and Food Science, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Brazil.
Gene. 2025 Jul 20;958:149489. doi: 10.1016/j.gene.2025.149489. Epub 2025 Apr 15.
The global dissemination of antimicrobial resistance (AMR) is a critical public health concern. The persistence of AMR in the environmental sector, exemplified by carbapenem-resistant Acinetobacter baumannii (CRAB), underscores the critical interconnectedness between human activity, environmental contamination, and the global spread of multidrug-resistant bacterial pathogens. In this study, A. baumannii strain EW779 was isolated from a water sample from a stream impacted by anthropogenic activities in São Paulo State, Brazil, exhibited an extensive drug resistance profile, and harbored chromosome-borne bla gene. Genomic analysis revealed that EW779 belongs to the hospital-associated high-risk ST79/ST233 subclone KL9-OCL10. This strain harbored a wide resistome associated with mobile genetic elements such as Tn2008, Tn7::In2-4, and Tn3. Virulence genes mainly related to biofilm formation, immune evasion, and cell invasion were found, evidencing its pathogenicity as putative hypervirulent. Comparative genomic analysis revealed that many AMR and virulence traits were shared among ST79/ST233 subclone KL9-OCL10 circulating in Brazil, indicating the occurrence of a successful and potentially epidemic subclone capable of spreading across different regions. The analysis of single nucleotide polymorphism differences among all ST79/ST233 subclone KL9-OCL10 showed a genetic similarity among strains from the same Brazilian state, indicating geographic separation. These findings highlight the environmental persistence and dissemination of a hospital-associated high-risk CRAB clone, emphasizing their epidemiological importance. Therefore, this study contributes to understanding the genomic dynamics of ST79/ST233 subclone KL9-OCL10 and reinforces the need for monitoring the spread of CRAB strains across clinical and environmental settings.
抗菌药物耐药性（AMR）的全球传播是一个关键的公共卫生问题。以耐碳青霉烯鲍曼不动杆菌（CRAB）为例，AMR在环境领域的持续存在凸显了人类活动、环境污染与多重耐药细菌病原体全球传播之间的关键联系。在本研究中，鲍曼不动杆菌菌株EW779是从巴西圣保罗州受人为活动影响的一条溪流的水样中分离出来的，该菌株表现出广泛的耐药谱，并携带染色体携带的bla基因。基因组分析表明，EW779属于医院相关的高风险ST79/ST233亚克隆KL9 - OCL10。该菌株携带与Tn2008、Tn7::In2 - 4和Tn3等移动遗传元件相关的广泛耐药组。发现了主要与生物膜形成、免疫逃避和细胞侵袭相关的毒力基因，证明其作为假定的高毒力病原体的致病性。比较基因组分析表明，在巴西流行的ST79/ST233亚克隆KL9 - OCL10中共享许多AMR和毒力特征，表明存在一个能够在不同地区传播的成功且可能流行的亚克隆。对所有ST79/ST233亚克隆KL9 - OCL10之间单核苷酸多态性差异的分析表明，来自巴西同一州的菌株之间存在遗传相似性，表明存在地理隔离。这些发现突出了医院相关高风险CRAB克隆在环境中的持久性和传播，强调了它们的流行病学重要性。因此，本研究有助于了解ST79/ST233亚克隆KL9 - OCL10的基因组动态，并强化了监测CRAB菌株在临床和环境环境中传播的必要性。
