Multiple-antibiotic resistance mediated by structurally related IncL/M plasmids carrying an extended-spectrum beta-lactamase gene and a class 1 integron.
A conjugative IncL/M plasmid (pSEM) conferring resistance to gentamicin, amikacin, kanamycin, sulfonamides, and expanded-spectrum cephalosporins was found in pathogenic strains of Salmonella enterica serotype Typhimurium. Resistance to aminoglycosides was encoded by a sul1-type class 1 integron (In-t3). An extended-spectrum beta-lactamase gene, bla(SHV-5), was identified 3. 5 kb downstream of the integrase (intI1) gene of In-t3. Nucleotide sequence analysis of the 5.3-kb bla(SHV-5)-In-t3 region of pSEM highlighted striking similarities with IncL/M plasmids isolated from nosocomial gram-negative pathogens, conferring resistance to expanded-spectrum cephalosporins and aminoglycosides.
Villa
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L
Laboratory of Bacteriology and Medical Mycology, Istituto Superiore di Sanità, Rome, Italy.
Pezzella
C
C
Tosini
F
F
Visca
P
P
Petrucca
A
A
Carattoli
A
A
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D018550:Cephalosporin Resistance; D002874:Chromosome Mapping; D018432:Drug Resistance, Multiple / Q000235:genetics*; D004587:Electrophoresis, Agar Gel; D016023:Integrins / Q000235:genetics*; D010957:Plasmids / Q000235:genetics*; D019779:Salmonella enterica / Q000187:drug effects / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics*
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D016023:Integrins; D001618:beta-Lactamases