RESUMO
Eighty-five extended-spectrum beta-lactamase-producing Enterobacteriaceae from a Slovak hospital have been studied. SHV-2a was predominant, but other variants have been detected, namely, SHV-5, SHV-12, TEM-12, TEM-15, and TEM-132, which differed from TEM-1 by amino acid substitutions R164H, E240K, and I173V and had kinetic properties similar to those of TEM-28.
Assuntos
Infecções por Enterobacteriaceae/epidemiologia , Enterobacteriaceae/efeitos dos fármacos , Hospitais , beta-Lactamases/metabolismo , Antibacterianos/farmacologia , Enterobacteriaceae/enzimologia , Infecções por Enterobacteriaceae/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Análise de Sequência de DNA , Eslováquia/epidemiologia , Resistência beta-Lactâmica , beta-Lactamases/genética , beta-Lactamas/farmacologiaRESUMO
Eleven genotypically related Klebsiella pneumoniae isolates were obtained from 11 patients. All isolates were resistant to third-generation cephalosporins due to the production of SHV-2a extended-spectrum beta-lactamase. Comparison of the outer membrane protein profiles revealed one isolate that lacked porins. This porin-deficient isolate was also resistant to cefoxitin (MIC 128 microg ml(-1)) and moxalactam (MIC 64 microg ml(-1)) and had elevated MIC of meropenem (2 microg ml(-1)) when compared to porin-expressing isolates (2-8, 4 and <0.06-0.125 microg ml(-1), respectively). Higher MICs, associated with loss of porins in outer membrane, were also observed for cefotaxime (4-8-fold), cefepime (>2-16-fold), ciprofloxacin (4-16-fold), imipenem and aztreonam (2-16-fold), but there was no significant difference among MICs of ceftazidime. The porin-deficient mutant was probably selected in vivo during ofloxacin therapy.