Prevalence of PER-۱- type Extended-Spectrum Beta-Lactamaes in Clinical Strains of Pseudomonas aeruginosa Isolated from Tabriz, Iran

Objective(s) The aim of this study was to investigate the presence of PER-۱-type ESBLs in drug resistant Pseudomonas aeruginosa isolates. Materials and Methods During one-year period (۲۰۰۸-۲۰۰۹), following isolation and identification of ۵۶ P. aeruginosa, the E-test method was performed for determination of minimal inhibitory concentration of ceftazidim. The isolates that they had MIC≥۱۶ µg/ml against ceftazidim were used for determination of ESBL-producing by combined disk test (CDT) and double disk synergy test (DDST) methods. Bla PER-۱genewas investigated by PCR.P. aeruginosa KOAS was used as positive control. Results Twenty-nine (۵۱.۷۸%) out of fifty six isolates had MIC≥۱۶ µg/ml to ceftazidime, twenty two (۷۵.۸۶%) of them were ESBL producers. Some isolates (۲۷.۵%) contained bla PER-۱ gene. Conclusion PER-۱-type ESBLs producing P.aeruginosa has not been reported previously in Tabriz but there has been a rather high prevalence of it.

Keywords:

Combined Disk Test , Double Disk Synergy Test , Extended- Spectrum Beta- Lactamase , PER-۱gene , Pseudomonas aeruginosa