Three-year analysis of microbial aetiology and antimicrobial susceptibilities of PD peritonitis.

The first-line antibiotic treatment of peritoneal dialysis (PD) peritonitis has to cover the most common causative microorganisms. Our aim was to analyse antimicrobial sensitivities of different empirical protocols for initial therapy of PD peritonitis. We analysed the aetiological microorganisms of PD peritonitis and their antimicrobial sensitivities during a 36-month period. Clinical characteristics of the cases were recorded. Altogether 86 PD peritonitides were diagnosed during the study period. In 58 cases, microbial cultures were positive with 72 different causative agents. 28 cases (33%) were culture-negative. Over-representation of icodextrin users was noted among the culture-negative cases. Staphylococcus aureus was the most frequent causative agent, often leading to severe course of illness. Of antimicrobial protocols for initial treatment of peritonitis tested in vitro, the combination of a first-generation cephalosporin and an aminoglycoside was superior to the combination of a first-generation cephalosporin and ceftazidime as well as to fluoroquinolone monotherapy but similar to the combination of vancomycin and ceftazidime. Based on antimicrobial sensitivities we continue using an aminoglycoside in the empirical treatment of PD peritonitis. In the present material, users of icodextrin PD fluid were over-represented among patients with culture-negative peritonitis.