First detection of transferable metallo-b-lactamases in the Netherlands

Abstract number: P895

al Naiemi N., Rijnsburger M.C., Savelkoul P.H.M., Llamas M., Sparrius M., Vandenbroucke-Grauls C.M., Debets-Ossenkopp Y.J.

Objectives: Metallo-b-lactamases (MBLs) are of special importance due to their role in microbial resistance to b-lactam antimicrobial agents, especially carbapenems. The prevalence of Pseudomonas aeruginosa strains that produce MBLs is increasing worldwide. Currently, nothing is known on the prevalence of these strains in The Netherlands. We determined the prevalence and the type(s) of MBLs produced by strains of Pseudomonas species isolated at the VU University Medical Center, in Amsterdam, The Netherlands.

Methods: During the first 7 months of 2007, the susceptibility profiles of 650 isolates from 329 patients were analysed. Isolates with decreased susceptibility to imipenem- and/or meropenem were tested for the production of MBL with MBL E-test. Site of infection/colonisation, and location of the patient in the hospital at the moment of strain isolation were recorded. DNA fingerprinting of the strains was performed with amplified fragment length polymorphism analysis (AFLP) to determine clonal relations. Transfer of resistance was investigated with conjugation experiments. The presence of VIM MBL genes was determined by PCR with generic primers. Further molecular characterisation of resistance genes confirmed the resistance pattern.

Results: Of 329 patients, 12 (3.6%) carried a MBL-positive Pseudomonas strain. Six strains were associated with clinical infection. The urinary tract was the most common site of infection. Epidemiological and molecular analysis showed no indications for a clonal outbreak in our hospital. Results of the conjugation experiment showed that these resistance genes were transferable. VIM PCR confirmed the production of VIM MBL in Pseudomonas isolates of two patients.

Conclusion: To the best of our knowledge, this is the first report that describes infections caused by MBL-producing Pseudomonas spp. strains in The Netherlands. Although the prevalence of metallo-b-lactamases is yet low, these results signal the need for development of accurate diagnostic tests by clinical laboratories to detect the presence of these resistance genes, so that specific isolation precautions can be taken to control their dissemination.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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