Genes Encoding Aminoglycoside O-Nucleotidyltransferases Are Widely Spread Among Streptomycin Resistant Strains of and .

Thermotolerant species and are actually recognized as the major bacterial agent responsible for food-transmitted gastroenteritis. The most effective antimicrobials against are macrolides and some, but not all aminoglycosides. Among these, susceptibility to streptomycin is reduced by mutations in the ribosomal RPSL protein or by expression of ANT(6)-I aminoglycoside O-nucleotidyltransferases. The presence of streptomycin resistance genes was evaluated among streptomycin-resistant isolated from humans and animals by using PCR with degenerated primers devised to distinguish , and other -like genes. Genes encoding ANT(6)-I enzymes were found in all possible combinations with a major fraction of the isolates carrying a previously described -like gene, distantly related and belonging to the new sub-family . Among isolates, was uniquely found functional in , as shown by gene transfer and phenotype expression in , unlike detected coding sequences in that were truncated by an internal frame shift associated to RPSL mutations in streptomycin resistant strains. The genetic relationships of isolates with ANT(6)-Ie revealed one cluster of strains presented in bovine and humans, suggesting a circulation pathway of strains by consuming contaminated calf meat by bacteria expressing this streptomycin resistance element.