Table 1_Circulation of ESBL-producing Klebsiella pneumoniae at the human–animal–environment interface in farms on the central coast of Peru.xlsx

Antibiotic-resistant bacteria, such as Extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-Kp), represent a major threat to public health. Despite increasing reports of community-acquired ESBL-Kp infections, the dynamics of ESBL-Kp in low- and middle-income countries communities remains poorly understood. This study aimed to detect the fecal carriage of ESBL-Kp at the human–animal–environment interface in Peru and to characterize underlying molecular mechanisms involved. We detected 15 ESBL-Kp isolates among 652 (2.3%) fecal and water samples (i.e., 244 dairy cows from 25 farms, 261 pigs from 25 farms, 58 dogs, 39 farmers, and 50 water sources). ESBL-Kp was isolated from two humans, two dogs, four cows, three pigs, and four water sources. Genomic analyses identified 10 different ESBL-Kp sequence types (STs), including high-risk clones ST11, ST307, and ST37, as well as ST45, ST111, ST1, ST348, ST789, ST881, and ST983, and three CTX-M-encoding genes (blaCTX-M-15, blaCTX-M-27, blaCTX-M-14). Four ESBL-Kp STs (ST348, ST983, ST789, and ST11) were found in more than one source, both within and between farms. In particular, two ESBL-Kp ST983 isolates, one from a human and one from a cow on the same farm, differed by 37 SNPs and had almost identical genetic profiles, suggesting bacterial clonal exchange across host species or contamination from a common source. Likewise, two nearly identical ST348 isolates were recovered from a cow and a water source on the same farm, suggesting ESBL-Kp exchange between livestock and water. Our results highlight the circulation of ESBL-Kp across humans, animals, and water in rural environments in Peru, representing one of the first genomic studies exploring potential cross-species ESBL-Kp relatedness in Latin America. Our study supports the need to implement sanitary measures to limit the cross-species spread of antimicrobial-resistant bacteria and to reduce water source contamination in Peru.