Evaluation of Frequency of AmpC β-Lactamase producing Escherichia coli and Klebsiella pneumoniae strains, in urine specimens of Patients Referring to Tehran s Milad Hospital (2017)

Introduction and Objectives: The production of beta-lactamase enzymes is the main mechanism of resistance to betalactam antibiotics in enterobacteriaceae. AmpC beta-lactamases are one of the hydrolyzing enzymes of penicillins, cephalosporins and monobactams. Today, the emergence and spread of bacterial resistance to antibiotics are a serious alarm in the treatment of infections. Therefore detection of producing AmpC beta-lactamases strains by using phenotypic methods will be important in determination of the appropriate treatment protocol.Materials and Methods: five hundred strains of E. coli and K. pneumoniae were isolated by standard biochemical tests from urine specimens of milad hospital in tehran ( March to September 2017). To detection of phenotypic AmpC beta-lactamase activity, the MAST AmpC detection set were used.Results: Of the 500 cases that were isolated from the urine samples, 235 (47%) strains of Escherichia coli and 265 strains (53%) of Klebsiella pneumoniae were present. 331 (66.2%) were isolated from female and 169 (33.8%) were isolated from male patients. 167 (33.4%) were inpatients and 333 (66.6%) were outpatients. The patient s age range was 1 to 94 years. Out of 500 samples, were identified to have producing AmpC β-lactamases with Mast AmpC detection set . Also, 66 strains (13.2 %) were detected positive by this phenotypic method.conclusions: increase the prevalence of AmpC beta-lactamases producing Escherichia coli and Klebsiella pneumoniae, is an important issue in urinary tract infections. They can cause serious problems for infection control and antibiotic treatment. Therefore, to prevent the spread of resistant strains, timely identification with reliable laboratory methods and definitive treatment with appropriate antibiotics, can be very helpful.

کلیدواژه ها:

AmpC β-lactamases ، Escherichia coli ، Klebsiella pneumoniae ، phenotypic method