Antimicrobial resistance and spread of class 1 integrons among Salmonella serotypes.
The resistance profiles, for 15 antimicrobial agents, of 333 Salmonella strains representing the most frequent nontyphoidal serotypes, isolated between 1989 and 1998 in a Spanish region, and 9 reference strains were analyzed. All strains were susceptible to amikacin, ceftazidime, ciprofloxacin, and imipenem, and 31% were susceptible to all antimicrobials tested. The most frequent types of resistance were to sulfadiazine, tetracycline, streptomycin, spectinomycin, ampicillin, and chloramphenicol (ranging from 46 to 22%); 13% were resistant to these six drugs. This multidrug resistance pattern was found alone or together with other resistance types within serotypes Typhimurium (45%), Panama (23%), and Virchow (4%). Each isolate was also screened for the presence of class 1 integrons and selected resistance genes therein; seven variable regions which carried one (aadA1a, aadA2, or pse-1) or two (dfrA14-aadA1a, dfrA1-aadA1a, oxa1-aadA1a, or sat1-aadA1a) resistance genes were found in integrons.
Guerra
B
B
Area de Microbiología, Departamento de Biología Funcional, Universidad de Oviedo, Principado de Asturias, Spain.
Soto
S
S
Cal
S
S
Mendoza
M C
MC
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics; D004352:Drug Resistance, Microbial / Q000235:genetics; D018432:Drug Resistance, Multiple / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests; D019779:Salmonella enterica / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D012703:Serotyping
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins