Background and Objectives: The emergence and spread of multidrug resistant (MDR) and extended spectrum b-lactamase (ESBL) producing strains reduces the number of effective drugs that can be used for treatment. The aim of this study was to evaluate the susceptibility profile of Enterobacteriaceae isolated from UTIs, specifically MDR and ESBL producing strains, to fosfomycin and other antibiotics.Materials and Methods: The study was performed during a 6 month period (February 2014 to August 2015). A total of 219 non-duplicate urinary isolates of Enterobacteriaceae were collected. Identification and susceptibility testing was done according to standard microbiological procedures and the Kirby- Bauer test, respectively. Based on the results obtained from susceptibility testing, MDR bacteria were recovered and identification of ESBL production was done according to CLSI recommendation.Results: Isolates of E. coli and Klebsiella spp. were responsible for 80.8% and 12.8% of patients with UTIs respectively. The rates of resistance to ampicillin, cefazolin, nalidixic acid, trimethoprim-sulfamethoxazole were 86.3%, 79.4%, 68.5% and 63.9% respectively. In contrast, high sensitivity rates were detected to fosfomycin, amikacin and amoxicillin-clavulanic acid with 97.3%, 91.8% and 80.8%, respectively. Of all isolates, 167 (76.3%) were detected as MDR and 75 (34.2%) as ESBL producing strains.Conclusion: The rate of antibiotic resistance among uropathogens Enterobacteriaceae is remarkably high. The most effective antibiotic was fosfomycin. Moreover, susceptibility to fosfomycin is over 90% for MDR and ESBL producer isolates. Therefore, fosfomycin can be a good option for treating UTIs.

Background: Nosocomial infection caused by Acinetobacter baumannii has emerged as a world-wide serious problem in the emergence of multidrug-resistant (MDR). Infections caused by antibiotic-resistant strains of A. baumannii cannot be completely eliminated among the infected patients. This study aimed to monitor antibiotic resistance among A. baumannii strains isolated from burnt children. Methods: After performing biochemical identification tests on 115 isolates, 62 were detected as A. baumannii. Minimum inhibitory concentration (MIC) was used to test susceptibility to colistin, and disk agar diffusion was used for the susceptibility of the isolates to the antibiotics Ciprofloxacin, Amikacin, Gentamicin, Cefepime, Meropenem, Imipenem, Ceftazidime, Levofloxacin and Piperacillin/Tazobactam. Bacterial species were isolated and identified as multidrug-resistant (MDR), extensively drug-resistant (XDR) and pan drug-resistant (PDR), based on the susceptibility patterns to elected antibiotics, deputing different classes of antimicrobial. Results: The antibiotic susceptibility pattern out of a total of 62 bacterial strains used in this study. Thirty-six (58%) strains were categorized as MDR, 17 (27. 5%) as XDR, and nine (14. 5%) as PDR. Conclusion: To reduce the threat of antimicrobial resistance, MDR, XDR and PDR A. baumannii strains must be evaluated by all clinical microbiology laboratories.

Introduction: Multi-drug resistant (MDR) P. aeruginosa is constantly increasing and causing severe issues in combatting widely spread health problems. The aim of this study was to assess colistin susceptibility in MDRP. aeruginosa isolates obtained from different infection sites.Methods: Ninety clinical isolates of P. aeruginosa were collected from different hospitals of the Tabriz University of Medical Sciences. All isolates were identified using standard microbiology tests. The disk diffusion susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Antibiotic disks used in this study included ciprofloxacin, levofloxacin, ceftazidime, amikacin, gentamicin, cefepime, imipenem, meropenem, ticarcillin/clavulanic acid, piperacillin, aztreonam, and colistin. The MIC (Minimum Inhibitory Concentration) of colistin was determined by the agar dilution method according to CLSI guidelines.Results: MDR isolates were found in 75.6%, in which there was a high frequency in wound specimens (23.3%), followed by blood (17.8%), urine (15.6%), trachea (13.3%), and peritoneum (5.6%). High resistance rate (above 50%) was observed with piperacillin, aztreonam, ceftazidime, cefepime, meropenem, gentamicin, amikacin, ciprofloxacin, and levofloxacin. All isolates were found to be susceptible to colistin through the disk diffusion method; however, two isolates were non-susceptible in the agar dilution method.Conclusion: The present study shows a high frequency of MDR P. aeruginosa in our subjects, the limitations of empirical therapy, and the need for susceptibility testing. The most effective antibiotic against MDRP. aeruginosa was colistin. Therefore, colistin may be an alternative antimicrobial agent for infections due to MDRP. aeruginosa.