High-Risk Clones of the Non-Fermenting Gram-Negative Bacilli Pseudomonas aeruginosa and Acinetobacter baumannii in Brazilian Aquatic Environments: A Systematic Review of Clonal Diversity and Antimicrobial Resistance
Yan Corrêa Rodrigues, Pabllo Antonny Silva dos Santos, Carolynne Silva dos Santos, Daniele Melo Sardinha, Allysson Freires Diniz, Bianca Nunes da Silva, Jamily Vitória dos Santos Silva, Caio Augusto Martins Aires, Danielle Murici Brasiliense, Karla Valéria Batista Lima, Ana Luiza da Silva, Cintya de Oliveira SouzaAntimicrobial-resistant Pseudomonas aeruginosa and Acinetobacter baumannii are major One Health threats, yet the environmental distribution of their epidemic lineages in Brazil remains poorly characterized. This systematic review aimed to synthesize evidence on the clonal diversity, antimicrobial resistance, and geographic distribution of molecularly typed P. aeruginosa and A. baumannii recovered from Brazilian aquatic environments. Searches were conducted in PubMed/MEDLINE, Scopus, Web of Science, SciELO, and LILACS/BVS, following PRISMA 2020. Eleven studies published between 2015 and 2026 were included, comprising 66 unique molecularly typed environmental isolates: 59 P. aeruginosa and seven A. baumannii. Among P. aeruginosa, 24 sequence types (STs) were identified, including the recognized high-risk clones ST244, ST277, and ST235. Four A. baumannii isolates belonged to ST79/International Clone 5, while ST1278, ST3355, and ST744 represented additional lineages. Clinically relevant resistance determinants included blaSPM-1, blaVIM-2, blaKPC-2, and blaOXA-23. Evidence was geographically concentrated and frequently based on selective molecular characterization. Brazilian aquatic environments therefore harbor both established high-risk clones and diverse additional resistant lineages within a One Health framework.