Characterization of an IncF2:A-:B- plasmid harboring fosA3 gene in a Shiga toxin-producing Escherichia coli O26:H11 isolated from a child with diarrhea in Japan.

A conjugative IncF2:A-:B- plasmid carrying fosA3 was identified in a STEC O26:H11 strain from a child with diarrhea in Japan, indicating potential for resistance spread.

• Why it matters: The global spread of fosfomycin-resistant genes among pathogenic E. coli strains raises concerns about treatment options and the effectiveness of antimicrobial therapy for STEC infections.
• What they did: Researchers screened 206 STEC strains from humans and found two fosfomycin-resistant strains; one harbored the fosA3 gene on a transferable plasmid, with sequence analysis suggesting horizontal gene transfer.
• The result: The study highlights the potential for fosA3 dissemination among diverse STEC strains, underscoring the need for monitoring fosfomycin resistance and characterizing resistance plasmids.