Poster Session 9: Miscellaneous| Volume 8, ISSUE 8, P650, September 2009

S131 Antimicrobial susceptibility in Gram-negative nosocomial retroperitoneal infections

      Introduction and Objectives

      The microbiological pattern of nosocomially acquired retroperitoneal suppurative infections has not studied so far probably due to their very rare incidence. Therefore, our aim was to study pathogens involved and their antimicrobial susceptibility.

      Material and Methods

      Multicenter, retrospective case-control study involved data from urological clinics in Serbia, covering period 2000–2007 year. Variety of common clinical parameters was collected but microbiological pattern was particularly studied. Urinary tract pathogens were identified and the susceptibility to 9 antimicrobials determined. Descriptive statistics and logistic regression were used for data analysis.


      In total sample of 93 adult subjects with renal suppurations we found 19 cases of nosocomial origin and 74 controls. The results of the final regression shown that history of malignancy and chronic renal failure significantly increased the risk of developing nosocomial retroperitoneal infection (odds ratio [OR] OR = 22.3, OR = 4.8, respectively). Overall, 67 bacteria isolated in 15 cases and 36 controls. There were significant differences in isolated Pseudomoas aeruginosa (OR = 6.6), mixed pathogens (OR = 6.9), number of pathogens (OR = 2.1), Gram positive bacteria (OR = 6.3) between both groups of cases and controls. Resistance rates for all agents and all Gram-negative organisms were higher in isolates from cases than controls, except against carbapenems. There were significant differences in bacterial susceptibility to ceftriaxone, cefotaxime and ofloxacine in cases compared to controls.


      Antibiotics commonly used for the treatment of nosocomially acquired retroperitoneal infections are less effective. Our results represent an initial step in defining a high-risk group that merits intensive infection control efforts.