بررسي مولكولي ژن هاي بتالاكتاماز طيف گسترده تيپ TEMدر ايزوله هاي اشريشياكلي و كلبسيلا پنومونيه جدا شده از نمونه هاي باليني

Molecular Study of TEM Type Extended-Spectrum Beta-Lactamase Genes in Escherichia Coli and Klebseilla Pneumoniae Isolates.

Background and Objectives: Emergence of antibiotic resistance is a main problem in microbial infection control. Production of extended spectrum beta-lactamases (ESBLs) can cause antibiotic resistance in bacteria. This study was conducted to evaluate antibiotic sensitivity profiles and the presence of blaJEm gene in Escherichia Coli and Klebseilla. Pneumoniae isolates collected from different clinical specimens. Materials and Methods: In this prospective study (2008-2009) clinical specimens including tracheal aspirates, urine, blood, bronchial secretions, sputum, peritoneal fluid, wound and throat swabs were collected from educational hospitals of Tabriz University of Medical Sciences. We performed antibiotic sensitivity tests (Kirby-Bauer Method) on E.coli and K. Pneumoniae isolated from specimens. Antibiotic discs that were used in this study werecefotaxime, ceftazidime, ceftriaxone, azteronam, amikacin, piperacillin/tazobactam, cefuroxim, cefepim and imipenem. Combind disk test was also used by ceftazidime, ceftazidime/clavolanic acid, cefotaxime and cefotaxime/clavolanic acid. E. coli ATCC 35218 and E.coli ATCC 25922 strains were used as TEM-positive and negative controls respectively. BlaTEM genes were detected by using PCR technique. Results: From total number Of 41 E. coli isolates 36 (87.8%) contained blaTEm gene. All of the Ecoli isolates were sensitive to imipenem, while, 36 of them (87.8%) were resistant to azteronam and 40 of them (97.5%) were ESBL producers. From total number of 47 K. Pneumoniae isolates, all were sensitive to imipenem, while 43 of them (97.8%) were sensitive to cefotaxime, 41 isolates (87.2%) showed resistance to azteroname and 46 isolates (97.8%) were ESBL producers of which 35 isolates (74.4%) contained blaTEM genes. Conclusion: High rate of resistance in E. coli (80.4%) and K. Pneumoniae (91.4%) isolates .Undelines the importance of accurate sensitivity tests. Keywords: Escherichia Coli, Klebseilla Pneumoniae, Extended spectrum beta lactamase (ESBL), Disk agar diffusion, Polymerase chain reaction. ^Corresponding author: