[Class 1 integrons among Salmonella enterica isolates producing different types of beta-lactamases from the health region of Tortosa (Spain)].
OBJECTIVE
To assess the frequency of class 1 integrons among isolates of Salmonella enterica producing different types of beta-lactamases from the health region of Tortosa, and to attempt to establish the resistance genes located within their variable regions.


METHODS
The presence of class 1 integrons and of aadA1, aadA2, dfrA1, tem-1, oxa-1 and pse-1 resistance genes within their variable regions was investigated by PCR in 100 ampicillin-resistant isolates of S. enterica (30 S. enteritidis, 56 S. Typhimurium and 14 from other serotypes) consecutively recovered in our laboratory between 2000 and 2001. Beta-lactamases were characterized by isoelectric focusing and PCR.


RESULTS
a) 6/57 TEM-1 producing isolates carried integrons: 1 S. ser Panama, 2 S. ser Enteritidis and 1 S. ser Typhimurium (1600 pb/aadA1-dfrA1); 1 S. ser Panama (1600 pb/aadA2-dfrA1); 1 S. ser Grumpensis (1500 pb 1 1700 pb; aadA2 and ??) b) All OXA-1 producing isolates (20 S. ser Typhimurium) bore an integron of 2000 pb/aadA1-oxa-1; c) All PSE-1 producing isolates (22 S. ser Typhimurium, most of them 104 phage type, and 1 S. enterica immobile [4,12:-:-]) harbored 2 integrons (1000 pb/aadA1 and 1,00 pb/pse-1).


CONCLUSIONS
The presence of class 1 integrons carrying oxa-1 or pse-1 resistance genes in all the OXA-1-producing and PSE-1-producing isolates investigated could have contributed to their spread and explain the increase in frequency of multiresistant S. ser Typhimurium isolates harboring these enzymes seen in the health region of Tortosa. In addition, we report the first isolate of S. ser enterica serotype Grumpensis harboring integrons.
Pérez-Moreno
Mar Olga
MO
Servicio de Análisis Clínicos, Hospital de Tortosa Verge de la Cinta, 43500 Tortosa, Tarragona, Spain. marolgap@terra.es
Carulla-Pont
Mireia
M
Pérez-Moreno
Marta
M
Jardí-Baiges
Anna María
AM
Llovet-Lombarte
María Isabel
MI
Tejedor-Ganduxé
Xavier
X
Zaragoza-López
Juan
J
D024881:Drug Resistance, Bacterial / Q000235:genetics* / Q000502:physiology; D006801:Humans; D032023:Integrons / Q000235:genetics* / Q000502:physiology; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D012480:Salmonella Infections / Q000235:genetics* / Q000503:physiopathology; D019779:Salmonella enterica / Q000187:drug effects / Q000235:genetics*; D013030:Spain; D001618:beta-Lactamases / Q000235:genetics
D001618:beta-Lactamases