POLYMERASE CHAIN-REACTION AMPLIFICATION OF BACTERIAL 16S RIBOSOMAL-RNA GENES IN INTERSTITIAL CYSTITIS AND CONTROL PATIENT BLADDER BIOPSIES

Purpose: Several characteristics of the chronic bladder disease called interstitial cystitis (IC) suggest an infectious etiology. However, a single causative organism has not been convincingly cultured in vitro , and DNA for a variety of microorganisms has been found inconsistentl y in bladder biopsies from IC patients. We therefore looked for a poss ible bacterial cause for IC by using a sensitive nested PCR assay on c ystoscopic bladder biopsy specimens obtained from IC patients and cont rols. Materials and Methods: Bladder biopsies were obtained at cystosc opy from 6 IC patients and 6 controls. DNA was extracted from these sp ecimens and PCR with 2-round amplification performed using nested prim ers from a highly conserved region of the bacterial 16s rRNA gene. Amp lified DNA was purified and sequenced using the Sequenase PCR Product Sequencing Kit, and the sequences obtained were compared with bacteria l rRNA gene sequences recorded in GenBank. Results: Biopsy specimens f rom all 6 patients and 6 controls were positive by PCR for DNA encodin g bacterial 16s rRNA. Sequence data indicated a predominant microorgan ism in 10 of the 12 specimens, with >95% homology to DNA from several different genera of bacteria including Acinetobacter, Propionobacteriu m, Salmonella, and Escherichia. None of the organisms identified by PC R had been cultured from tissue or urine obtained simultaneously from these persons, using sensitive culture techniques. Conclusions: These data indicate no difference between IC patients and controls in the pr oportion of bladder biopsies with PCR positivity or the type(s) of org anism present, providing additional evidence that IC is not associated with infection by a particular type of bacterium.