Prevalence of PER-1- type Extended-Spectrum Beta-Lactamaes in Clinical Strains of Pseudomonas aeruginosa Isolated from Tabriz, Iran

Document Type : Original Article


1 Department of Microbiology, Faculty of Medicine, and *Research Center of Infectious Diseases and Tropical Medicine, Tabriz University of Medical Sciences, Tabriz, Iran

2 Department of Clinical Laboratory Sciences, Faculty of Paramedicine, Urmia University of Medical Science


The aim of this study was to investigate the presence of PER-1-type ESBLs in drug resistant Pseudomonas aeruginosa isolates.
Materials and Methods
During one-year period (2008-2009), following isolation and identification of 56 P. aeruginosa, the E-test method was performed for determination of minimal inhibitory concentration of ceftazidim. The isolates that they had MIC≥16 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-1genewas investigated by PCR.P. aeruginosa KOAS was used as positive control.
Twenty-nine (51.78%) out of fifty six isolates had MIC≥16 µg/ml to ceftazidime, twenty two (75.86%) of them were ESBL producers. Some isolates (27.5%) contained bla PER-1 gene.
PER-1-type ESBLs producing P.aeruginosa has not been reported previously in Tabriz but there has been a rather high prevalence of it.


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