Antibiotic resistance genes and Salmonella genomic island 1 in Salmonella enterica serovar Typhimurium isolated in Italy.
Fifty-four epidemiologically unrelated multidrug-resistant Salmonella enterica serovar Typhimurium isolates, collected between 1992 and 2000 in Italy, were analyzed for the presence of integrons. Strains were also tested for Salmonella genomic island 1 (SGI1), carrying antibiotic resistance genes in DT104 strains. A complete SGI1 was found in the majority of the DT104 strains. Two DT104 strains, showing resistance to streptomycin-spectinomycin and sulfonamides, carried a partially deleted SGI1 lacking the flo(st), tetR, and tetA genes, conferring chloramphenicol-florfenicol and tetracycline resistance, and the integron harboring the pse-1 gene cassette, conferring ampicillin resistance. The presence of SGI1 was also observed in serovar Typhimurium strains belonging to other phage types, suggesting either the potential mobility of this genomic island or changes in the phage-related phenotype of DT104 strains.
Laboratory of Bacteriology and Medical Mycology, Istituto Superiore di Sanità, Rome, Italy. alecara@iss.it
Alessandra
A
Carattoli
Emma
E
Filetici
Laura
L
Villa
Anna Maria
AM
Dionisi
Antonia
A
Ricci
Ida
I
Luzzi
D015139:Blotting, Southern; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D004352:Drug Resistance, Microbial; D016521:Electrophoresis, Gel, Pulsed-Field; D005798:Genes, Bacterial / Q000235:genetics*; D016680:Genome, Bacterial; D006801:Humans; D007558:Italy; D008969:Molecular Sequence Data; D012480:Salmonella Infections / Q000382:microbiology; D019779:Salmonella enterica / Q000187:drug effects* / Q000235:genetics*
D004269:DNA, Bacterial