Abstract
Rectal swabs of 104 patients who underwent abdominal surgery were screened for ESBL producers. Sequence types (STs) and resistance genes were identified by whole-genome sequencing of 46 isolates from 17 patients. All but seven isolates were assigned to recognized STs. While 18 ESBL-producing E. coli (EPEC) strains were of unique STs, ESBL-producing K. pneumoniae (EPKP) strains were mainly ST14 or ST15. Eight patients harboured strains of the same ST before and after abdominal surgery. The most prevalent resistant genes in E. coli were bla EC (69.57%), bla CTX-M (65.22%), and bla TEM (36.95%), while bla SHV was present in only K. pneumoniae (41.30%). Overall, genes encoding ?-lactamases of classes A (bla CTX-M, bla TEM, bla Z), C (bla SHV, bla MIR, and bla DHA), and D (bla OXA) were identified, the most prevalent variants being bla CTX-M-15, bla TEM-1B, bla SHV-28, and bla OXA-1. Interestingly, bla CMY-2, the most common pAmpC ?-lactamase genes reported worldwide, and mobile colistin resistance genes, mcr-10-1, were also identified. The presence of bla CMY-2 and mcr-10-1 is concerning as they may constitute a potentially high risk of pan-resistant post-surgical infections. It is imperative that healthcare professionals monitor intra-abdominal surgical site infections rigorously to prevent transmission of faecal ESBL carriage in high-risk patients. ? The Author(s), 2024. Published by Cambridge University Press.
