Molecular epidemiology and resistance mechanisms involved in reduced susceptibility to amoxicillin/clavulanic acid in Klebsiella pneumoniae isolates from a chronic care centre

Mar Olga Pérez-Moreno, Maria José Centelles-Serrano, Maria Cortell-Ortolá, Isabel Fort-Gallifa, Joaquim Ruiz, Maria Isabel Llovet-Lombarte, Ester Picó-Plana, Anna Maria Jardí-Baiges

Resultado de la investigación: Contribución a una revistaArtículorevisión exhaustiva

11 Citas (Scopus)

Resumen

The aim of this work was to investigate the molecular epidemiology and mechanisms responsible for reduced susceptibility to amoxicillin/clavulanic acid (AMC) amongst cefazolin-susceptible Klebsiella pneumoniae isolates from patients admitted to a chronic care institution. In total, 51 (29.8%) of 171 K. pneumoniae isolates recovered between 2006 and 2008 were non-susceptible to AMC, of which 45 were susceptible to cefazolin. Nucleotide sequencing analysis revealed that 19 produced IRT-11 and the remaining 26 were OXA-1-producers. All of the OXA-1-producing isolates harboured the aac(6′)-Ib-cr-bla OXA-1 cassette array, which in 23 isolates was located together with catB3 and arr3 within a class 1 integron and associated with qnrS2 (in 3 cases the integron lacked the qacEΔ1 and sul1 or sul3 genes). Genotyping analysis performed by enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) identified three different patterns amongst IRT-11-producing isolates (E1 to E3), with E1 being the most prevalent (63.2%), whilst the OXA-1-producing isolates were assigned to patterns E3 and E3a (isolates carrying typical class 1 integrons), E4 (isolates carrying defective integrons) and E5 (isolates without integrons). Genes encoding IRT-11 and OXA-1 were transferred by conjugation, and aac(6′)-Ib-cr and qnrS2 were systematically co-transferred with blaOXA-1. These results demonstrate that the high prevalence of decreased susceptibility to AMC amongst K. pneumoniae isolates from a chronic care hospital was mainly due to the simultaneous spread of two different clones, one of which comprised isolates producing IRT-11 and the other one comprised isolates that had acquired either the blaOXA-1 gene located in a class 1 integron and linked to qnrS2 or the blaIRT-11 gene.

Idioma originalInglés
Páginas (desde-hasta)462-466
Número de páginas5
PublicaciónInternational Journal of Antimicrobial Agents
Volumen37
N.º5
DOI
EstadoPublicada - may. 2011

Huella

Profundice en los temas de investigación de 'Molecular epidemiology and resistance mechanisms involved in reduced susceptibility to amoxicillin/clavulanic acid in Klebsiella pneumoniae isolates from a chronic care centre'. En conjunto forman una huella única.

Citar esto