Detection of Urease Gene in Infected Calculi Using Polymerase Chain Reaction

Kim, Kwang Jin; Lee, Chang Whoon; Shin, Han Chul

Abstract

PURPOSE: Urea-splitting organisms have known to participate in the formation of infected calculi, but sometimes, causative organisms were not detected in urine culture. We compared results of polymerase chain reaction which detect urease gene in infected calculi to urine culture, to follow pathogens which involved in the formation of infected calculi and establish preventive antimicrobial therapy.
MATERIALS AND METHODS
Urine culture were performed in 25 patients who were diagnosed as infected calculi. The DNA was extracted from the PBS solution that was used for washing stones and lysis solution which inserted after calculi crushing. And then, PCR were performed with universal primers for beta-globin gene, 16S ribosomal RNA gene, and primers for urease gene of Proteus mirabilis and Ureaplasma urealyticum which synthesized by order. Stone analysis was performed using infrared spectroscopy.
RESULTS
Proteus mirabilis and Ureaplasma urealyticum were not detected in urine culture. All results of PCR to beta-globin gene and 16S ribosomal RNA gene were negative in calculi washing solution. In 18 of 25 cases(72.0%), the result of PCR to 16S ribosomal RNA gene were positive in calculi lysis solution. Each 2 and 3 of 18 cases(total; 27.7%) which were positive in PCR to 16S ribosomal RNA gene, Proteus mirabilis and Ureaplasma urealyticum were cultured respectively. From 16 cases which were available to perform infrared spectroscopic stone analysis, 7 cases were shown to have specfic absorbance band of infected calculi and were positive in PCR to 16S ribosomal RNA gene.
CONCLUSIONS
We detected urea-splitting organisms in crushed calculi specimen using PCR. It suggests that PCR for urea-splitting organisms will be helpful to identify process of infected calculi and causative organisms.