First Detection of a Fosfomycin Resistance Gene, fosA7 , in Salmonella enterica Serovar Heidelberg Isolated from Broiler Chickens.

We previously described Salmonella enterica serovar Heidelberg isolates harboring a chromosomal gene cluster similar to the glutathione S -transferase gene, a putative fosA gene conferring resistance to fosfomycin. Here, we show that this new gene, named fosA7 , confers resistance to fosfomycin. The introduction of fosA7 into the fosfomycin-susceptible Salmonella enterica serovar Enteritidis resulted in a substantial increase in the fosfomycin MIC. This finding increases the awareness of antibiotic resistance in Salmonella Heidelberg from broilers as related to the food safety and public health.