Background: The aim of this study was to determine the prevalence of K. pneumoniae encoded bla CMY-2 gene, isolated from clinical specimens. Methods: In this Analytic-descriptive cross-sectional study, 144 isolates of Klebsiella spp. were collected from the clinical specimens such as wounds (7cases), supra pubic (1 case), blood (8 cases), septum (2 cases), catheter tips (3 cases), urine (106 cases), CSF (1 case), skin lesion (1 case), tracheal (9 cases), anal (2 cases), throat (1 cases) and eye culture (3 case) from Rasht hospitals from February to August 2013. After identification of isolates by biochemical methods, the antibiotic susceptibility test (Kirby-Bauer method) was done according to CLSI guideline against 20 antibiotics. The combined disk method (Double disk) was then carried out for detection of ESBLs of Klebsiella spp. Among ESBL producers of Klebsiella spp. blaCMY-2 was detected by PCR using specific primers. Then, PCR products were subjected to electrophoresis on 1.5 % agarose gel. Finally, PCR products were confirmed by sequencing.Results: Among the Klebsiella 144 clinical isolates, 57 (39.6%) isolates were ESBL producers. The most prevalent ESBL producers were isolated from urine sample (33.57). The most resistance in Klebsiella spp. were belong to Oxacillin and Amoxicillin (98.1% and 97.2%, respectively) and Imipenem was the most effective antibiotic (95.3%) against all isolates. Among 57 ESBL producers of Klebsiella spp. only 12 cases (21.01%) were contained blaCMY-2 gene. This is the first report of blaCMY-2 gene found in Klebsiella spp. in Iran.Conclusion: Due to high frequency of ESBL producing Klebsiella spp. isolated from clinical specimens, antibiogram should be conducted to choose the best antibiotic against Klebsiella spp and empirical treatment should be avoided to reduce antibiotic resistance development.

Background & Objective: The production of plasmid-mediated AmpC beta-lactamases (PMABLs) among urinary Klebsiella pneumoniae isolates causes a severe problem to the successful treatment of urinary tract infections (UTIs). This study was designed to evaluate antimicrobial resistance, the presence of AmpC beta-lactamase genes, and the genetic relatedness among K. pneumoniae strains separated from patients with UTI. Materials & Methods: In this cross-sectional descriptive study, a total of 100 K. pneumoniae isolates were collected from UTI cases in Milad Hospital, Tehran, Iran. The sensitivity of the isolates to 12 antibiotics was tested using the Kirby-Bauer disk diffusion method. AmpC production was determined using a boronic acid combined-disk test. Polymerase chain reaction (PCR) was carried out to screen all isolates with family-specific PMABL genes. The genetic relatedness of AmpC-producing isolates was determined by an enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR). Results: Over a period of 11 months, PMABLs were detected in 49 isolates (49%) of K. pneumoniae. Resistance to at least three classes of antimicrobials was detected in 30 (61. 2%) PMABL producers. Among AmpC producers, 34 isolates harbored only one AmpC gene group, including MOX (n=11), EBC (n=8), ACC (n=7), CIT (n=4), FOX (n=2), and DHA (n=2). Multiple AmpC gene groups were detected in 15 isolates. The ERIC-PCR showed the polyclonal distribution of AmpC-producing isolates. Conclusion: In our study, a high frequency of AmpC-producing K. pneumoniae was observed. This is the first report of ACC type AmpC beta-lactamase in Iran. Strategies to minimize the spread of AmpC beta-lactamase-producing isolates should be implemented.

Background and Objectives: AmpC-producing Gram-negative bacterial (GNB) pathogens are distributed worldwide, especially in clinical settings. This study aimed to determine the antibiogram and the type of AmpC-β-lactamase gene harboured by GNB pathogens implicated in chronic suppurative otitis media (CSOM) cases. Materials and Methods: Ear swab samples (300) collected from patients with active CSOM were analysed using standard microbiological techniques. Phenotypic and molecular detection of AmpC β-lactamase production was done by cefoxitin/cloxacillin double-disk synergy test and PCR respectively. Antibiogram was determined by disk diffusion technique. Results: Among the GNB pathogens isolated from CSOM patients, P. aeruginosa was the most predominant (36. 3%),followed by K. pneumoniae (22. 3%), and E. coli (13. 7%). Patients with active CSOM showed increased bacteria isolation rate from bilateral ear discharges than unilateral ear discharges. E. coli and P. aeruginosa were more prevalent among patients with duration of discharge >2 weeks,recording 9. 0% and 20. 3% respectively. AmpC β-lactamase producers accounted for 14. 0%,they were highly resistant (60%-100%) to cephalosporins, trimethoprim-sulfamethoxazole, ofloxacin, amoxicillin, and tetracycline, but very susceptible (70. 4%-100%) to ciprofloxacin, imipenem, and amikacin. Multiple antibiotic resistance indices of isolates ranged from 0. 7-0. 8. FOX-AmpC-β-lactamase gene was detected in 3. 9% of the isolates. Conclusion: The detection of AmpC β-lactamase-producing multidrug-resistant GNB pathogens harbouring FOX-AmpC-β-lactamase gene among patients with CSOM infections in our study is a serious public health problem which needs urgent intervention.