%0 Journal Article
%T Screening and confirmatory assays for detection of ESBLs (extendedspectrum  -lactamases) production by Klebsiella pneumoniae isolates M¨¦todos de triagem e de confirma  o para detec  o de BLEAs (beta lactamases de espectro ampliados) em isolados de Klebsiella pneumoniae
%A Eliana Carolina Vespero
%A Marcia Regina Eches Perugini
%A Halha Ostrensky Saridakis
%J Semina : Ci¨ºncias Biol¨®gicas e da Sa¨²de
%D 2007
%I Universidade Estadual de Londrina
%X ESBLs (extended-spectrum  -lactamases) are enzymes produced by Enterobacteriaceae, especially Klebsiella pneumoniae, which mediate resistance to extended-spectrum  -lactams and aztreonam. Considering the importance of detecting ESBLs producing strains, in this study, usual screening and confirmatory assays were compared. One hundred and seven strains of K. pneumoniae, isolated from patients with urinary tract infection, were screened for ESBLs production according to NCCLS 2005 guidelines, using broth microdilution in the Microscan Walkaway (Dade Behering) and Kirby-Bauer disk diffusion (KBD) test. Fifty-five strains selected as possible ESBL producers (51,4%), were submitted to confirmatory assays: E-test, double disk (DD) approximation and clavulanic acid (CA) association. Production of ESBLs was detected by the five methods used in 38 (69%) strains and 10 (18,2%) were negative only in DD. Seven strains (12,7%) did not present suggestive breakpoints in the Microscan Walkaway and were negative in the DD test, whereas the KBD values for the same strains obtained were indicative of ESBLs production. These results suggest that the combination of KBD breakpoints determination and CA association can be used as an efficient, alternative and less expensive system than the E-test. BLEAs ( -lactamases de espectro estendido) s o enzimas produzidas por v¨¢rias esp¨¦cies de Enterobacteriaceae, principalmente Klebsiella pneumoniae, as quais conferem resist¨ºncia aos  lactamicos de espectro ampliado e aztreonam. Considerando a importancia da detec  o de BLEAs, neste estudo foram comparados m¨¦todos de triagem e de confirma  o. As 107 amostras de K. pneumoniae, isoladas de pacientes com infec  o urin¨¢ria foram triadas quanto ¨¤ produ  o de BLEAs, segundo normas do NCCLS 2005, utilizando microdilui  o em caldo no Microscan Walkaway e teste de disco difus o de Kirby-Bauer (KBD). As 55 cepas selecionadas foram submetidas a ensaios de confirma  o como poss¨ªveis produtoras de BLEAs (51,4%): E-test, aproxima  o com discos duplos (DD) e associa  o com ¨¢cido clavulanico (CA). A produ  o de BLEAs foi detectada pelos cinco m¨¦todos em 38 (69%) amostras e 10 amostras (18,2%) foram negativas para o teste DD. Sete amostras (12,7%) n o apresentaram valores sugestivos no m¨¦todo automatizado e tamb¨¦m foram negativos no teste de DD, mas os valores dos halos no teste de KBD foram indicativos da produ  o de BLEAs. Estes resultados sugerem que o uso combinado do m¨¦todo KBD e associa  o com CA podem ser utilizados como um sistema alternativo eficiente e menos dispendioso que o E-test.
%K K.pneumoniae
%K Beta-lactamases de espectro ampliado (BLEAs)
%K Triagem.
%U http://www.uel.br/revistas/uel/index.php/seminabio/article/view/3488