Dissemination of a VIM-positive Pseudomonas aeruginosa clone in a university hospital, Ankara, Turkey

Abstract number: 1733_862

Gurkan Aydin N., Metan G., Altun B., Zarakolu P.

Objectives: The aim of this study was to report the dissemination of a VIM-positive Pseudomonas aeruginosa clone in Hacettepe University Hospital in Ankara, Turkey.

Methods:P. aeruginosa strains (n = 26) isolated from various clinical specimens (4 blood, 7 urine, 12 pus, 1 cerebrospinal fluid, 1 bronchoalveolar lavage, 1 sputum) of patients with nosocomial infections in Hacettepe University Adult Hospital during January and July 2005 were included in the study. The isolates were identified by Phoenix System (Becton Dickinson, USA) and the antimicrobial susceptibility testing was performed by Etest (AB Biodisk, Sweden) method according to CLSI criteria. All the isolates were screened for carbapenem hydrolysing metallo-b-lactamase activity by imipenem-EDTA disk method phenotypically and genotypic detection was performed by PCR with bla-IMP and bla-VIM primers. Clonal diversity was examined by PFGE of SpeI-digested genomic DNA.

Results: The antimicrobial resistance of the isolates to ceftazidime was 27% where as 31% to piperacillin-tazobactam, 35% to imipenem, 38% to meropenem, 46% to tobramycin, 58% to ciprofloxacin. All the isolates were carrying the blaVIM gene and the blaIMP gene was not detected in any of them. However, only 8 (31%) were phenotypically positive for metallo-b-lactamase activity. There were 3 clones with one dominant clone (n = 22).

Conclusion:P. aeruginosa is a multidrug resistant pathogen of nosocomial infections. Although metallo-b-lactamase activity as a resistance mechanism has been reported increasingly worldwide, there are few reports from Turkey. Our finding of dissemination of this clone is pointing out the emergence of this resistance pattern in our country.