AUTHOR=Gelalcha Benti D. , Mohamed Ruwaa I. , Gelgie Aga Edema , Kerro Dego Oudessa 

TITLE=Molecular epidemiology of extended-spectrum beta-lactamase-producing-Klebsiella species in East Tennessee dairy cattle farms

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1439363

DOI=10.3389/fmicb.2024.1439363

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>The rising prevalence of Extended-Spectrum Beta-Lactamase (ESBL)-producing <italic>Klebsiella</italic> species (spp.) poses a significant threat to human and animal health and environmental safety. To address this pressing issue, a comprehensive study was undertaken to elucidate the burden and dissemination mechanisms of ESBL-<italic>Klebsiella</italic> spp. in dairy cattle farms.</p></sec><sec><title>Methods</title><p>Fifty-seven <italic>Klebsiella</italic> species were isolated on CHROMagar™ ESBL plates and confirmed with MADLI-TOF MS and whole genome sequenced from 14 dairy farms.</p></sec><sec><title>Results and discussion</title><p>Six families of beta-lactamase (<italic>bla</italic>) (<italic>bla</italic><sub>CTX−M</sub>, <italic>bla</italic><sub>SHV</sub>, <italic>bla</italic><sub>TEM</sub>, <italic>bla</italic><sub>OXY</sub>, <italic>bla</italic><sub>OXA,</sub> and <italic>bla</italic><sub>SED</sub>) were detected in ESBL-<italic>Klebsiella</italic> spp. genomes. Most (73%) of isolates had the first three types of beta-lactamase genes, with <italic>bla</italic><sub>SHV</sub> being the most frequent, followed by <italic>bla</italic><sub>CTX−M</sub>. Most (93%) isolates harbored two or more bla genes. The isolates were genotypically MDR, with 26 distinct types of antibiotic resistance genes (ARGs) and point mutations in <italic>gyrA</italic>, <italic>gyrB</italic>, and <italic>parC</italic> genes. The genomes also harbored 22 different plasmid replicon types, including three novel IncFII. The IncFII and Col440I plasmids were the most frequent and were associated with <italic>bla</italic><sub>CTXM−27</sub> and <italic>qnrB19</italic> genes, respectively. Eighteen distinct sequence types (STs), including eight isolates with novel STs of <italic>K. pneumoniae</italic>, were detected. The most frequently occurring STs were ST353 (<italic>n</italic> = 8), ST469 (<italic>n</italic> = 6), and the novel ST7501 (<italic>n</italic> = 6). Clusters of ESBL-<italic>Klebsiella</italic> strains with identical STs, plasmids, and ARGs were detected in multiple farms, suggesting possible clonal expansion. The same ESBL variant was linked to identical plasmids in different <italic>Klebsiella</italic> STs in some farms, suggesting horizontal spread of the resistance gene. The high burden and dual spread mechanism of ESBL genes in <italic>Klebsiella</italic> species, combined with the emergence of novel sequence types, could swiftly increase the prevalence of ESBL-<italic>Klebsiella</italic> spp., posing significant risks to human, animal, and environmental health. Immediate action is needed to implement rigorous surveillance and control measures to mitigate this risk.</p></sec>