Multidrug resistance is mediated by large plasmids carrying a class 1 integron in the emergent Salmonella enterica serotype [4,5,12:i:-].
A multidrug-resistant Salmonella enterica serotype [4,5,12:i:-] clone carried a class 1 integron harboring dfrA12 and aadA2 gene cassettes and bla(TEM-1), aac(3)-IV, cmlA1, and tetA genes located in large plasmids of about 140 kb (carrying spv) or 120 kb (lacking spv). Several segregants, lacking multidrug resistance, contained a plasmid smaller than the parental one and no longer hybridized with probes for the lost resistances. The genes mediating resistance to ampicillin, chloramphenicol, and tetracycline in the [4,5,12:i:-] clone are different from those found in the pentadrug-resistant serotype Typhimurium DT104 clone.
Area de Microbiología, Departamento de Biología Funcional, Universidad de Oviedo, 33006 Oviedo, Principado de Asturias, Spain.
B
B
Guerra
S M
SM
Soto
J M
JM
Argüelles
M C
MC
Mendoza
D000668:Ampicillin Resistance; D002702:Chloramphenicol Resistance; D004251:DNA Transposable Elements; D018432:Drug Resistance, Multiple; D005798:Genes, Bacterial; D008826:Microbial Sensitivity Tests; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D019779:Salmonella enterica / Q000187:drug effects* / Q000235:genetics*; D013045:Species Specificity; D013753:Tetracycline Resistance
D004251:DNA Transposable Elements