Suspension precipitation: A simple sediment-collecting method for microbiological culturing in diagnosis of...

Rapid and accurate microbiological detection is crucial for effective treatment of peritonitis patients with peritoneal dialysis (PD). Although centrifugation of dialysis effluents can increase the pathogen culture-positive rate, a lack of both centrifugation facilities and experienced staff has prevented its widespread implementation, particularly in basic-level hospitals in developing countries. Thus, we developed a simple peritoneal sediment-collecting method, suspension precipitation method, for microbiological diagnosis of peritonitis.

In the suspension precipitation method, drained effluent bags from individual patients were hung for 1 hour to allow the suspension to drip to the bottom layer of the bag for sediment collection. Sediments obtained by centrifugation from the same batch of dialysis effluent were used as positive controls. Both sediment sample types were then cultured in blood-culture bottles. Subsequent analysis of the pathogen-positive detection rate and species comparison between the two methods were undertaken.

Among 90 PD patients, the pathogen positive-detection rate between methods was comparable, as demonstrated by 75 (83.33%) with the suspension precipitation method and 77 (85.56%) by the centrifugation method. Their positive pathogen species were also similar, and the concordance rate was 97.78%.

The suspension precipitation method is a simple, convenient, and reliable peritoneal sediment-collecting method that is suitable for a wide array of uses, particularly in basic-level hospitals without centrifugation technology.