Multiple Plasmid Vectors Mediate the Spread of fosA3 in Extended-Spectrum-β-Lactamase-Producing Enterobacterales Isolates from Retail Vegetables in China

Abstract

This report provides important information on the transmission and epidemiology of fosA3 among Enterobacterales isolates from vegetables. The rate of occurrence of fosA3 in ESBL-producing Enterobacterales from retail vegetables is high, and fosA3 was found to be carried by diverse plasmids. Some novel genetic contexts of fosA3 and novel fosA3 -carrying plasmids, including several plasmid types common in K. pneumoniae , were identified, increasing the number of known transfer vectors for the fosA3 gene and reflecting the complexity of fosA3 transmission in Enterobacterales . The capture of fosA3 by the resident plasmid of K. pneumoniae will accelerate the spread of fosA3 in K. pneumoniae , one of the most pathogenic species in clinical medicine. Considering the clinical importance of fosfomycin, and the fact that vegetables are directly consumed, the fosfomycin resistance genes present a risk of transmission to the human body through the food chain and thus pose a threat to public health.