| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1300-1 | ||||
Resumo:Carbapenem-resistant Acinetobacter baumannii (CRAB) is a critical priority pathogen that has emerged as a global public health threat. The worldwide spread of CRAB resulted in a concerning rise in morbidity and mortality rates, particularly among hospitalized immunocompromised patients. However, it has also been reported in non-hospital environments, remarking on the potential for adaptation and dissemination besides hospital walls. Worryingly, a high-risk clone OXA-23-producing A. baumannii (Ab120 strain) was isolated from a polluted urban river in São Paulo, Brazil. This study aimed to perform a comparative phylogenomic analysis between the environmental OXA-23-positive A. baumannii strain Ab120 and hospital-associated isolates, in order to elucidate the background spillover of critical priority A. baumannii beyond hospital settings in Brazil. Genomic DNA of the environmental (Ab120) and clinical (5.14) strains was extracted using the PureLink extraction kit and sequenced using Illumina NextSeq550 platform. De novo assembly was performed by Unicycler and in silico prediction was accomplished by bioinformatics tools. Multilocus sequence typing (MLST) analysis revealed that Ab120 and 5.14 isolates belong to the sequence type ST79. Resistome analysis predicted a wide range of resistance genes to clinically relevant antibiotics, including β-lactams (blaOXA-23, blaOXA-65, blaTEM-1A, blaTEM-150, and adc-5), aminoglycosides (aph(3')-VIa, aph(6)-Id, aph(3″)-Ib, and sat-1), sulphonamides (sul2), trimethoprim (dfrA1), and phenicols (floR), whereas, macrolide resistance genes (mphE and msrE) were exclusively identified in the clinical 5.14 strain. The genetic context investigation of Ab120 and 5.14 strains revealed that the region containing the blaOXA-23 gene was integrated into a transposon known as Tn2008. Virulome analysis revealed both strains carried several virulence genes associated with adherence, biofilm formation, two-component system, phospholipase C/D, immune evasion, heme utilization, iron uptake, and serum resistance. Noteworthy, the stress adaptation gene katA was predicted only in the environmental A. baumannii Ab120 strain. Strikingly, phylogenomic analysis based on SNPs in 1961 core genes revealed that the Ab120 and 5.14 A. baumannii ST79 are distant from each other (3043 SNP differences), whereas the environmental strain Ab120 was genomically related (SNP counts ranging between 168 and 311) to 10 clinical strains (at least 8 from the same hospital) identified between 2010 and 2017 in São Paulo. On the other hand, the human strain 5.14 is distant from any other ST79 strain, but relatively close to 6 human strains (886 – 1437 SNP differences) identified from Goiás, Pernambuco e Rio Grande do Sul states. These findings reveal a very similar resistome and virulome among phylogenomically related clinical and environmental OXA-23-producing A. baumannii ST79 strains, indicating the potential of critical-priority carbapenem-resistant A. baumannii to spread beyond hospital settings, representing a major concern within a One Health perspective. Palavras-chave: carbapenemase, critical-priority pathogen, genomic surveillance, one health Agência de fomento:Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) | |||||