Genomic Surveillance of ESBL-Producing Klebsiella pneumoniae Across Municipal Wastewater and Food Animal Production Environments.

Extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-K. pneumoniae) is a priority antimicrobial-resistant pathogen with the capacity to persist and disseminate across environmental and food animal production systems. This study conducted genomic surveillance of ESBL-K. pneumoniae recovered from municipal wastewater treatment plants and food animal production environments in Fayetteville, North Carolina. A total of 449 wastewater and livestock farm environment samples were analyzed. K. pneumoniae was recovered from 162 (36.1%) samples, including 68 (15.1%) ESBL-producing isolates. Antimicrobial susceptibility testing showed that 77.9% of ESBL-producing isolates were multidrug-resistant. Polymerase chain reaction identified blaCTX-M-1, blaSHV, and blaACT as the predominant resistance genes. Whole-genome sequencing of selected isolates identified diverse antimicrobial resistance determinants, virulence-associated genes, and plasmid replicons, with IncFIB(K) being the predominant plasmid type. Phylogenetic analysis demonstrated close genetic relatedness between wastewater and farm environment isolates, with some differing by only 0-6 single-nucleotide polymorphisms, suggesting possible dissemination between environmental reservoirs. These findings highlight municipal wastewater and food animal production environments as important reservoirs of ESBL-K. pneumoniae and reinforce the value of integrated genomic surveillance within a One Health framework to monitor the emergence and spread of antimicrobial resistance.