A preliminary study on the role of Bacteroides fragilis in stent encrustation

To preliminarily study the characteristics of bacterial flora distribution in the urine of ureteral stent encrustation patients as well as the relation between Bacteroides and stent encrustation.

Patients undergoing ureteral stenting were included in the study and divided into encrustation group and non-encrustation group based on the condition of stent encrustation. The urine of patients was collected to undergo 16s DNA test to compare the bacterial flora distribution characteristics of the two groups. The bacterial genus with highest abundance in the urine of encrustation group was used for animal experiment. A rat model with a foreign body in the bladder was created, in which the rats were injected with the aforesaid bacterial genus. A control group injected with normal saline was also formed. The incidence of foreign body tube encrustation between the two groups was compared.

The urine collected from the patients in encrustation group contained a variety of bacteria, while dominant bacteria genera included g_Lactobacillus (23.1%), g_Bacteroides (18.8%) and g_norank_Bacteroides (17.1%). While the urine from the non-encrustation group was less diverse in bacteria flora, as the major bacteria genera were g_Escherichia-Shigella (32.2%), g_Enterococcus (24.9%) and g_Pseudomonas (18.2%). Bacteroidetes in the encrustation group were significantly higher, therefore Bacteroides fragilis in this genus was adopted for animal experiment, resulting in a higher incidence of foreign body tube encrustation in the bladder among rats.

The present study enriches our knowledge about ureteral stent encrustation and reveals that the target regulation of urine bacteria is worth further research and clinical application.