Survey of Frequency in Extended-Spectrum Beta-Lactamase Producing Enterobacteriaceae and Determination of the Antibiotic Resistant Pattern in Clinical Specimens in Teaching Hospitals of Ahvaz Jundishapur University of Medical Sciences

Document Type : Original Article


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

2 Department of Microbiology, Faculty of Medicine, International Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

3 Department of Microbiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.


Background and Objectives:Enterobacteriaceae produce the extended-spectrum beta-lactamases which is considered as an important resistant mechanism of beta-lactam antibiotics. The resistance to beta-lactam antibiotics is the main problem in the bacterial infections therapy. The present study aims to explore the frequency of the extended-spectrum beta-lactamase in isolated bacteria and to determine the isolates’ resistant pattern to antibiotics.
Subjects and Methods: A total of 240 isolated  Enterobacteriaceae  were collected from the clinical samples of Golestan and Imam Khomeini hospitals which were identified by standard biochemical tests. Next, the sensitivity of the isolates to the nine antibiotics was determined with Disk diffusion method. Then, isolated generator Enterobacteriaceae were detected with the combination disk method on the basis of CLSI criteria.
Results: Among 240 isolated bacteria E. coli, Entrobacter and Klebsiella comprised 71.3,27.1 and 1.2% most of the isolates. According to the results of the phenotypic tests, 108 (45%) isolates out of 240 Enterobacteriaceae were beta-lactamase producers.  Moreover, the results of diffusion disk showed that resistance of E coli, Entrobacter and Klebsilla isolates to ceftazidim and cefotaxim were 43.3 and 55.8 respectively.
Conclusion:The current study demonstrates that generator Enterobacteriaceae strains are increasing.Therefore, study of the extended-spectrum beta-lactamase enzymes would help in   prescribing the suitable medicine and consequently could prevent the spread of resistant bacteria.


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