Characterization of a self-transferable plasmid from Salmonella enterica serotype typhimurium clinical isolates carrying two integron-borne gene cassettes together with virulence and drug resistance genes.
An unusual self-transferable virulence-resistance plasmid (pUO-StVR2) was found in nine multidrug-resistant (ACSSuT phenotype) Salmonella enterica serotype Typhimurium clinical isolates that were assigned to four different phage types and a single and distinctive XbaI pulsed-field gel electrophoresis profile. pUO-StVR2 is an IncFII plasmid of about 140 kb in length carrying the spvA, spvB, and spvC (Salmonella plasmid virulence) and rck (resistance to complement killing) genes. It also carries the oxa1/aadA1a (ampicillin resistance and streptomycin-spectinomycin resistance) gene cassette configuration located within a class 1 integron with qacEDelta1/sul1 (ammonium antiseptics resistance and sulfadiazine resistance); the transposon genes merA, tnpA, and tnpR (mercury resistance, transposase, and resolvase of Tn21, respectively); and the catA1 (chloramphenicol resistance) and tet(B) (tetracycline resistance) genes. The insertion of resistance genes into a Salmonella virulence plasmid constitutes a new and interesting example of plasmid evolution and presents a serious public health problem.
Guerra
Beatriz
B
Departamento de Biología Funcional, Area de Microbiología, Universidad de Oviedo, 33006 Oviedo, Principality of Asturias, Spain.
Soto
Sara
S
Helmuth
Reiner
R
Mendoza
M Carmen
MC
D001434:Bacteriophage Typing; D004269:DNA, Bacterial / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D004352:Drug Resistance, Microbial; D005798:Genes, Bacterial / Q000235:genetics*; D032023:Integrons / Q000235:genetics*; D010957:Plasmids / Q000235:genetics*; D019779:Salmonella enterica / Q000187:drug effects / Q000235:genetics* / Q000472:pathogenicity; D012703:Serotyping; D045564:Transposon Resolvases; D037521:Virulence Factors
D004269:DNA, Bacterial; D037521:Virulence Factors; C473490:Tn21 resolvase; D045564:Transposon Resolvases