Background: The aim of this study was to investigate the frequency of ESBL producing Klebsiella pneumonia at an educational hospital in shahrekord, Iran.Methods: This study was conducted at Shahrekord University of medical science. Totally, 150 isolates of Klebsiella pneumonia bacteria were selected from out-patient of Hajar and kashani university hospitals. Uropathogens were identified through culture, microscopy and biochemical tests. To detect possible ESBL production, combined double disc synergy test was performed by disc of ceftazidime (30 mg) alone and in the presence of clavulanate (30 mg/10 mg) at a distance of 25 mm, on a Mueller–Hinton agar plate. Detection of SHV gene was examined in ESBL positive strains by PCR.Results: Combined double disc synergy test was applied to detect ESBL in 75 Klebsiella pneumoniae isolates that are resistant to ceftazidime using ceftazidime. Among the 48 ESBL-producing K. pneumonia strains, 18 (37.5%) were identified as SHV producing strains.Conclusion: The spread of ESBL-producing bacteria has been strikingly rapid worldwide, indicating that continuous monitoring systems and effective infection control measures are required. Therapeutic options for infections due to ESBL producers become increasingly limited. Molecular detection and identification of beta lactamases would be essential for a reliable epidemiological investigation of antimicrobial resistance. Therefore, ESBL producing organisms should be identified quickly so that appropriate antibiotic usage and infection control measures can be implemented.

Background: Resistance to beta-lactam antibiotics along with clinical isolates is frequently resulting production of b-lactamase enzymes. In recent years, the production of extended spectrum b-lactamases (ESBLs) and AmpC b-lactamase among clinical isolate especially Escherichia coli is greatly increased. On the other hand, beta lactamase genes have several subfamilies, and designing universal primers could be valuable to detect all of them. Therefore, the aim of this study was to survey prevalence of phenotypic ESBLs and detection of SHV and AmpC (CITM, FOX) –type b-lactamase genes by using universal primers through PCR.Methods: A total of 500 clinical samples were collected from hospitals of Tehran and 200 E.coli isolates were detected by standard biochemical tests. Subsequently, these isolates were screened for b-lactamase production by Disk diffusion method and combined disk. Resistant isolates were evaluated for molecular assessing of SHV, CITM and FOX genes by using PCR.Results: Among entire of 200 E.coli, 128 (64%) isolates were selected via phenotypic tests for detection of bla-SHV and bla-AmpC (CITM, FOX) genes via PCR. With 95% confidence, 7 (5.5%) and 13 (10.2%) E.coli harbor bla-SHV and bla-CITM, respectively. Fox gene was not detected in any samples.Conclusion: Results were showed that complete detection of b-lactamase enzymes is essential for resistant control and the appropriate prescription of b-lactam drugs. So using molecular assay with phenotypic test is important.

Background: Pseudomonas aeruginosa is an opportunistic pathogen associated with nosocomial infections. The emergence and dissemination of metallo-b-lactamases (MBLs) and extended-spectrum- b -lactamases (ESBLs) have contributed to the high rate of resistance among the p. aeruginosa isolates. This study investigated the prevalence of IMP, SHV and PER genes in p. aeruginosa isolates.Methods: Antibiotic susceptibility testing was performed using the minimal inhibitory concentrations (MIC). Then the polymerase chain reaction (PCR) was used for the detection of 3 genes encoding IMP, SHV and PER.Results: Of the 60 isolates tested, 38 (63.3%) were resistant to piperacilin, 42 (70%) to ceftazidime, 44 (73.3%) to imipenem and 45 (75%) to cefepime. Five (8.3%) and 8 (13.3%) of the isolates had PER and SHV genes by PCR results. In this study IMP gene was not found.Conclusion: According to this study, P. aeruginosa isolates were highly resistant to antibiotics. Therefore the susceptibility of isolates should be tested before treatment. Among the three b -lactamases genes studied the highest prevalence was related to SHV gene. Given the clinical significance of MBLs and ESBLs producing isolates, identification of these organisms is essential in the hospitals in order to get a better therapeutic response and control of bacterial dissemination.