Objective: To determine what role non-culturable microorganisms play in the etiology of interstitial cystitis (IC).
Materials and methods: Thirty patients fulfilling NIH criteria for the diagnosis of interstitial cystitis and sixteen control patients with culture negative urine gave written informed consent and underwent bladder biopsy. Polymerase chain reaction (PCR) using two sets of universal primers for bacterial 16S rDNA was performed on urine from the cystoscope and on a cold cup bladder biopsy specimen. Of the PCR positive bladder biopsies, three patients with interstitial cystitis and three controls were randomly selected and cloned. Ten clones from each were sequenced and putative taxonomic assignments made.
Results: 12/26 (46%) IC and 5/12 (42%) control urine specimens and 16/30 (53%) and 9/15 (60%) bladder biopsies were PCR positive, respectively. The bacterial populations in the two patient groups tested appeared to be different based upon analysis of the 16S rRNA sequences.
Conclusions: Both IC and control patients had non-culturable bacteria in their bladders. A random sampling of the two populations revealed that the bacterial populations are different, suggesting a possible link between one or more bacterial species and IC.