Caracterización de la región variable de integrones clase 1 presentes en cepas nosocomiales de Klebsiella pneumoniae / Characterization of the variable region within class 1 integrons in Klebsiella pneumoniae nosocomials strains

ABSTRACT

Background: Integrons are responsible for the capture and dissemination of resistance genes in Gram-negative bacteria. Aim: To characterize the variable region within class 1 integrons in nosocomial strains of Klebsiella pneumoniae. Material and Methods: Twenty-nine Klebsiella pneumoniae strains isolated from hospitalized patients were analyzed. The variable region of class 1 integrons was characterized by polymerase chain reaction and direct sequencing. Genetic localization of class 1 integrons was determined by bacterial conjugation. Results: Ten strains contained class 1 integrons, with sizes ranging from 750 to 2000 base pairs. One integrant element was present in nine strains and two elements in one single strain. Integrons were associated to plasmids. Cassettes aadA, aac(6)-Iq, orfD, dfrA]7, aadA5 and aadB were found. Conclusions: The presence of class 1 integrons may play an important role in the dissemination of hospital resistance against amino glycosides.