Klebsiella pneumoniae: estudo molecular dos fatores de resistÃncia e caracterizaÃÃo ultra-estrutural da aÃÃo de antibiÃticos β-lactÃmicos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Klebsiella pneumoniae is an enterobacteria responsible for a high incidence of hospital infections usually caused by strains carrier of multidrug resistance and producer of broad spectrum -lactamase (ESBL). This study aimed to determine the genes involved in the formation of classical beta-lactamases and ESBLs in Recife-PE, Brazil, and investigate the ultrastructural effects caused by different concentrations of betalactam antibiotics in isolates of K. pneumoniae producers of different types of betalactamases. It was analyzed 52 isolates of K. pneumoniae in order to search for blaSHV and blaTEM genes, from the microbiot and from community and hospital infections and for the investigation of blaCTX-M1 gene it was used 19 clinical isolates of K. pneumoniae that showed resistance to third-generation cephalosporins or aztreonam. It also was determined the minimum inhibitory concentrations (MICs) of these isolates against ceftazidime, cefotaxime and aztreonam antibiotics. Two isolates of nosocomial infection by K. pneumoniae were submitted to different sub-MICs of the ceftazidime, cefotaxime and aztreonam for analysis by Transmission and Scanning Electron Microscopy (TEM and SEM). The blaSHV gene was detected in 16 hospital isolates, 4 of the community and 9 of the microbiota, while the blaTEM gene was detected in 18 hospital isolates, 4 of the microbiot and 2 of the community. The blaCTX-M2 gene was detected in 3 isolates resistant both ceftazidime and cefotaxime. It was discovery a new SHV variant in one of the isolates and the presence of two variants previously reported, SHV-28 and SHV-108. The analysis of the 2 isolates of K. pneumoniae by TEM and SEM showed large morphological and ultrastructural changes on the isolates, when subjected to different sub-MICs of ceftazidime and cefotaxime. Our results suggest that isolates of K. pneumoniae carriers of different β-lactamases and resistant to different antibiotics may show large morphological and ultrastructural changes, when subjected to sub-MICs of the drug, which could enable a better performance of the immune system of a patient infected with this bacterial species

ASSUNTO(S)

klebsiella pneumoniae gene resistance mecanismo de resistÃncia medicina genes de resistÃncia klebsiella pneumoniae

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