RESUMO
Background: Metallo-ß-lactamases (MBL) confer high resistance to carbapenems in Pseudomonas aeruginosa (Psae). They are encoded in mobile elements of different genes (VIM, IMP, SMP, GIM), along with other resistance genes. Aim: To detect the presence of MBL in imipenem resistant Psae strains. Material and methods: Fifty-nine imipenem resistant Psae strains isolated from January 2004 to August 2005 in a University Clinical Hospital, were included. The presence of MBL was studied by Etest (phenotypic) and genotypic polymerase chain reaction (PCR) methods. To rule out a nosocomial outbreak, MBL positive strains, were studied by pulse field gel electrophoresis. Results: The presente of MBL was detected in eleven strains. AH were type VIM and were not clonally related. There was no concordance between phenotypic and genotypic MBL detecting methods. AH the strains were also multiresistant. Conclusions: The presence of MBL was detected in 19 percent of imipenem resistant Psae strains.
Assuntos
Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Antibacterianos/farmacologia , Imipenem/farmacologia , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/enzimologia , beta-Lactamases/genética , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/genética , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/genética , Eletroforese em Gel de Campo Pulsado , Genes Bacterianos/efeitos dos fármacos , Genes Bacterianos/genética , Imipenem/análise , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Infecções por Pseudomonas/genética , Pseudomonas aeruginosa/efeitos dos fármacos , Adulto Jovem , Resistência beta-Lactâmica/efeitos dos fármacos , Resistência beta-Lactâmica/genética , beta-Lactamases/análiseRESUMO
To investigate the distribution of the genes of two major metallo-beta-lactamases (MBL; i.e., IMP and VIM) and class 1 integrons (intI) in the clinical imipenem-resistant Pseudomonas aeruginosa, a total of 65 isolates, from a university hospital in Sichuan between December 2004 and April 2005 were screened for MBL genes by PCR using primers specific for bla ( IMP-1 ), bla ( VIM ) and bla ( VIM-2 ) genes. The MBL-positive isolates were further assessed for class 1 integrons by PCR using specific primers. The nucleotide sequences of several PCR products were also determined. The results revealed that the bla ( VIM ) gene was found in 81.5% (53/65) of all isolates, bla ( VIM-2 ) gene was found in only 1 isolate and the intI gene was observed in 45.3% (24/53) of bla ( VIM )-positive isolates. One isolate carried simultaneously both bla ( IMP-1 ) and intI genes, and to the best of our knowledge this is the first report of such isolate in southwest China. These observations highlight that the genes for VIM beta-lactamase and class 1 integrons were predominantly present among the imipenem-resistant P. aeruginosa tested, confirming the current widespread threat of imipenem-resistant, integron-borne P. aeruginosa.
Assuntos
Antibacterianos/farmacologia , China , Primers do DNA/química , Farmacorresistência Bacteriana , Regulação Bacteriana da Expressão Gênica , Imipenem/farmacologia , Integrons , Testes de Sensibilidade Microbiana , Modelos Genéticos , Infecções por Pseudomonas/genética , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/metabolismo , Análise de Sequência de DNA , beta-Lactamases/metabolismoRESUMO
The present work was carried out to study the genetic factors for multi-drug resistance in clinically isolated strains of Ps. aeruginosa. Conjugal transfer of resistance factor between Ps. aeruginosa strains was observed, while no transfer was found from Ps. aeruginosa to E. coli strains. The DNA analysis by gel-ectrophoresis revealed the presence of plasmid in one strain [AQ 003] only. As no conjugal transfer or presence of plasmid was observed in other strains, it is suggested that in these strains resistance may be of chromosomal or genetic origin