Authors:Irina Gheorghe-Barbu, Marius Surleac, Ilda Czobor Barbu, Simona Paraschiv, Leontina Mirela Bănică, Liviu-Iulian Rotaru, Corneliu Ovidiu Vrâncianu, Mihai Niță Lazăr, Dan Oțelea, Mariana Carmen Chifiriuc
Abstract:
Acinetobacter baumannii, a notorious opportunistic pathogen, presents a formidable challenge in both clinical and environmental fields due to its resilience and ability to acquire resistance. This study undertook a comprehensive analysis of 183 A. baumannii isolates collected between 2019 and 2022 from intra-hospital infections (IHI), hospital sewages (Hs), wastewater treatment plants (WWTP), and adjacent river waters from two Southern cities, focusing on their resistome, viru-lome, and mobilome through isolation on chromogenic media, identification by MALDI-TOF-MS and antibiotic susceptibility testing by disk diffusion) followed by genotypic characterization [Whole Genome Sequencing (WGS), 3rd generation sequencing through the MinION (ONT) platform, pangenome description, and respectively horizontal gene transfer through conjugation assays]. Our findings reveal significant genomic plasticity and the prevalence of high-risk inter-national clones, underlining the potential of these isolates to act as reservoirs for antibiotic resistance genes (ARGs) that could be dynamically exchanged between clinical and environ-mental settings through mobile genetic elements (MGEs) such as the pMAL1 plasmids and the critical role of WWTPs in the persistence and spread of A. baumannii. Moreover, our study pre-sents the first report of the co-occurrence of blaOXA-23 and blaOXA-72 in A. baumannii ST2 clone. Thus, our research underscores the necessity for integrated surveillance and targeted in-terventions across healthcare and environmental sectors to mitigate the risk posed by this adaptable pathogen.