Kamelia Torabizadeh *, Eskandar Fathiazar and Azad Rahmani

Urinary tract infection (UTI) is the second most common infection in human. Klebsiella pneumoniae is an opportunistic pathogen bacteria, that accounts for nosocomial infections. Prevalence of extended-spectrum beta lactamase (ESBLs) in K. pneumoniae strains led to the spread of antibiotic resistance and mortality in patients. This study was done to evaluate the resistance to antibiotics in K. pneumoniae isolated from urinary tract infections. This study was performed in Alzahra, Shariaty, Kashany, Mahdieh hospitals and References laboratories during 2009-2010 in Isfahan. According to statistical formula, 378 urine samples of patients with UTI were evaluated. Bacterial identification was performed with microbiological methods, including gram staining, differential environment and ESBLs production with screening and confirmatory tests. Antibiotics resistant pattern was performed with Kirby Bauer method. From 378 sample, frequency of ESBLs in K. pneumoniae strains isolated in hospitalized and out patients was 64% and 22% respectively. According to antibiogram results 90.5%, 65%, 57.1%, 60%, 31.6%, 0%, 35%, 78.6% and 19% of K.pneumoniae strains isolated in hospitalized patients were resistant to Ampicillin, Ceftazidime, Cefotaxime, Cefepime, Amikacin, Imipenem, Ciprofloxacin, Trimethoprim/ Sulfamethoxazole and Nitrofurantoin respectively and 70.6%, 41.7%, 24%, 15%, 0%, 21.4%, 28.6%, 18.5%, 25.9% and 34.6% of K. pneumoniae strains isolated in out patients were resistant to Ampicillin, Cefazolin, Ceftazidime, Cefotaxime, Amikacin, Gentamicin, Nalidixic acid, Ciprofloxacin, Trimethoprim/ Sulfamethoxazole and Nitrofurantoin. The results showed that frequency of ESBLs and antibiotic resistant in isolated bacteria from hospitalized patients was more prevalence than isolated bacteria from out patients. Perhaps the most important reason for this problem is unidentifying of ESBLs producer strains in laboratories and cephalosporins and Aztreonam prescription in UTI patients.