MON-075 DISCORDANT CULTURE-NEGATIVE PERITONITIS RATES IN DIFFERENT MICROBIOLOGY LAB: A RESULT FROM THAILAND PDOPPS STUDY

Abstract

Most of Thailand peritoneal dialysis (PD) centers have culture-negative peritonitis (CNP) rate above the International Society of PD guideline’s threshold level (< 20%). The causes of high CNP rate in Thailand may result from different culture protocol which is yet to be elucidated. The PD bags were retrieved from PD patients with peritonitis from Thailand PDOPPS sites. The bag was submitted to local and central laboratories. The bags with delayed shipment (>24 hours), minute tear or damage were discarded. At local laboratories, the causative organism was identified using an individual lab protocol. At central laboratory, 50 ml of PD effluent was centrifuged and directly inoculated into broth and different agar plates. From 991 consented patients, 234 cases had 275 peritonitis episodes during June 2016 to December 2017. Ninety five and 93 episodes had random (with empirical/specific antibiotic) and first cloudy specimens (without antibiotic), respectively, submitted centrally. CNP rate was 10% lower in central lab compared to local lab (42.1% vs. 31.6%). The better yield results from a two-fold increase in the yield of fungal, mycobacterial and polymicrobial identifications (6.3% vs. 3.2%, 1.1% vs. 0%, and 10.5% vs. 4.2%, respectively). Positive locally cultured but negative centrally cultured rate was 5 in 95 episodes (5.3%). CNP rate was reduced by only 0.4% in specimen with concurrent antibiotic (31.6 vs. 31.2 %). Large volume of submitted PD effluent seems to play an important role in reducing CNP rate at least in Thailand. However, the differences in lab quality control cannot be excluded. Concurrent antibiotic does not play an important role in nowadays broth culture technique.