NONDEVELOPMENT OF RESISTANCE BY BACTERIA DURING HOSPITAL USE OF POVIDONE-IODINE

Since the bacterial ability to develop resistance against various fact ors of their surroundings is a well-known phenomenon, resistance again st iodine and specifically against povidone-iodine (PVP-I) has been wi dely investigated. Yet there is little known about bacterial resistanc e in long-term daily use of disinfectants in continuous ambulatory per itoneal dialysis (CARD) patients. The aim of our study was to investig ate whether on daily use of PVP-I over a period of at least 6 months c oagulase-negative staphylococci (CNS)-the predominant infective organi sms of peritonitis - developed resistance against PVP-I. At the cathet er exit site of 40 CARD patients we isolated 36 CNS. 23 CNS (CNS + PVP ) orginate from patients using PVP-I, 13 CNS (CNS + Cl) from patients using sodium hypochlorite (NaOCl) as disinfectant. The strains were bi otyped, antibiotic resistance patterns were determined and resistance against PVP-I or NaOCl was calculated as reduction factor using the qu antitative suspension test combined with a turbidimetric standardizati on. Resistance against PVP-I 0.01% and against NaOCl 0.005% was determ ined at two contact times (30 and 300 a) for each patient group. In ad dition, we investigated the effects of plasmid loss on sensitivity to PVP-I. Out of 5 multiple-antibiotic-resistant CNS, 3 strains showed no difference in reduction factor against PVP-I before and after curing. There was no significant difference in reduction factor against NaOCl . CNS + PVP were even significantly more sensitive to PVP-I than CNS Cl. Taken together, our results demonstrate that long-term use of PVR -I does not cause any bacterial resistance in CNS of CAPD patients.