Mechanisms of carbapenemase-mediated resistance among high-risk Pseudomonas aeruginosa lineages in Peru

Objectives: Pseudomonas aeruginosa is one of the leading causes of healthcare-associated infections glob-ally. High-risk carbapenemase-encoding P. aeruginosa clones are disseminating in many regions. The aim of this study was to learn more about the lineages and mechanisms of resistance of P. aeruginosa circu-lating in Peru. Methods: A total of 141 carbapenemase-producing isolates recovered from hospitalized and ambulatory patients in Lima were sequenced and analyzed to infer their lineages through whole-genome sequence typing (wgST) and to identify their antimicrobial resistance genes. Results: wgST identified nine sequence types (STs); ST111 and ST357 were the most frequently encoun-tered (44.0% and 38.3%, respectively), followed by ST179 (8.5%), with the remaining six detected only sporadically. Among ST357 isolates, 96.3% carried the novel blaIMP-93 allele, whereas the remainder har-bored blaIMP-74. 74.2% of ST111 isolates co-harbored blaIMP-18 and blaVIM-2, while the rest carried either of these genes individually . All other ST lineages carried a single carbapenemase, which was either blaIMP-16, blaIMP-74, or blaVIM-2. Conclusion: Our study shows that the high-risk P. aeruginosa clones ST357, which harbors the novel blaIMP-93 , and ST111, which carries blaIMP-18 and blaVIM-2 , have apparently become endemic in the region. (c) 2022 The Author(s). Published by Elsevier Ltd on behalf of International Society for Antimicrobial

Automated summary

This study reveals the linages and mechanisms of resistance of Pseudomonas aeruginosa circulating in Peru. The results show that the high-risk P. aeruginosa clones ST357 carrying the novel blaIMP-93 gene and ST111 carrying blaIMP-18 and blaVIM-2 genes have become endemic in the region.