Bacterial pathogens in peritoneal dialysis peritonitis: Insights from next-generation sequencing.

BACKGROUND

Peritoneal dialysis (PD) peritonitis is a feared complication of PD, with significant sequelae for the patient. The cause of PD peritonitis is largely due to a single organism (≥75% of cases) and rarely due to multiple organisms.

METHODS

In this pilot study, we investigated 25 cases of PD peritonitis with 16S ribosomal RNA (rRNA) next-generation sequencing (NGS) techniques.

RESULTS

Total concordance between culture and NGS was noted. In addition, the NGS technique was highly sensitive, identifying 33 different bacteria (including a nonculturable bacterium), compared to 13 bacterial species using culture-based techniques. This was counterbalanced by a lack of specificity with NGS, largely due to the small size of the 16S rRNA gene segment sequenced.

CONCLUSIONS

For the clinician, our results suggest that PD peritonitis may often be a polymicrobial disease and that treating a dominant organism may not totally eradicate all bacterial contamination within the peritoneum. For the clinical scientist, additional use of a larger 16S rRNA segment (V5 or V6) is likely to outperform the use of the V4 segment only.