Identification and distribution of the clinical isolates of imipenem-resistant Pseudomonas aeruginosa carrying metallo-beta-lactamase and/or class 1 integron genes

J Huazhong Univ Sci Technolog Med Sci. 2008 Jun;28(3):235-8. doi: 10.1007/s11596-008-0301-8. Epub 2008 Jun 19.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • China
  • DNA Primers / chemistry
  • Drug Resistance, Bacterial*
  • Gene Expression Regulation, Bacterial*
  • Humans
  • Imipenem / pharmacology*
  • Integrons*
  • Microbial Sensitivity Tests
  • Models, Genetic
  • Pseudomonas Infections / genetics
  • Pseudomonas Infections / microbiology*
  • Pseudomonas aeruginosa / metabolism*
  • Sequence Analysis, DNA
  • beta-Lactamases / metabolism*

Substances

  • Anti-Bacterial Agents
  • DNA Primers
  • Imipenem
  • beta-Lactamases