Profile of urinary tract infections pathogens and their antimicrobial resistance patterns during three-year period (2009-2011) in the Clinical center Kragujevac

Urinary tract infections are common bacterial diseases and also a frequent reason for prescribing antibiotics. Knowledge about the type of pathogens and their resistance patterns may help the clinician to choose the correct treatment. In this study, the prevalence and the resistance pattern of the main bacteria responsible for urinary tract infections оf hospitalized patients in Clinical centar Kragujevac was evaluated throughout a tree-year period. Cross-sectional study in the hospital settings was conducted and urine samples were collected from 662 patients with urinary tract infections and tested using standard procedures. The disk-diffusion method on Mueller-Hinton agar according to Clinical and Laboratory Standards Institute guidelines (CLSI) was performed for assessment of antimicrobial susceptibility. The most frequently isolated pathogen were Klebsiella spp. (219 isolates, i.e. 33,1%), Proteus mirabilis (107 isolates, i.e. 16,2%), Enterobacter (86 isolates, i.e. 13%), Escherichia coli (82 isolates, i.e. 12,4%), Pseudomonas aeruginosa (70 isolates, i.e. 10,6%), Enterococcus spp (39 isolates, i.e. 5,9% ) and Proteus vulgaris (38 isolates, i.e. 5,7%). Group of patients older than 65 years was the largest one 426 (64,4%). Gram negative bacteria showed the highest degree of resistance (92.3% - 100%) to penicillins (ampicillin, amoxicillin, amoxicillin + clavulanic acid) and third-generation cephalosporins (cefotaxime, ceftriaxone and ceftazidime) (88.3% - 98, 4%), while Gram positive Enterococcus spp showed the highest degree of resistance to aminoglycosides (gentamicin and amikacin) (96.8% - 100%) and fluoroquinolone ciprofliksacin (100%). The lowest resistance rate of the studied Gram negative pathogens was to carbapenems (imipenem and meropenem) and piperacillin / tazobactam (6.9% - 35.5%), while the lowest level of resistance of gram positive Enterococcus spp was found to glycopeptide antibiotics (vancomycin and teicoplanin) (3.0% - 3.3%). When choosing antibiotics, the pharmacokinetics and pharmacodynamics, renal and liver function, adverse reactions with other drugs, as well as the results of susceptibility testing should be taken into consideration. According to our data, empiric treatment for Klebsiella spp, Proteus mirabilis, Enterobacter, Escherichia coli, Pseudomonas aeruginosa and Proteus vulgaris should include carbapenems or piperacillin / tazobactam, and when it comes to Enterococcus spp , glycopeptide antibiotics are appropriate choice.