Comparison of polymerase chain reaction and bacteria culture in peritoneal dialysis associated peritonitis

Abstract

Objective To evaluate clinical application value of polymerase chain reaction(PCR) detection for bacteria in peritoneal dialysis associated peritonitis(PDAP). Methods Peritoneal dialysis fluid specimens were collected from January 2014 to December 2014 in The First Affiliated Hospital of Anhui Medical University. Conventional bacterial culture and PCR detection were used respectively. According to the bacterial 16S rRNA gene, universal primers were devised and designed, based on reference, the specific primers of 17 kinds of experimental bacteria. Real-time fluorescent PCR(Real-time PCR, qPCR) amplification was implemented. The establishment of standard strain DNA extract was used as positive control; sterile double distilled water was used as negative control. Results (1) The traditional bacterial culture results showed that positive proportion was 26/40 in specimen of 40 cases, gram-positive strains accounting for 18/26. Main species were epidermis staphylococcus(5/26), hemolysis staphylococcus(4/26), escherichia coli(4/26), and streptococcus viridans(3/26).(2) The PCR detection results showed that total positive rate was 33/40 in 40 patients specimens, among which 2 cases of positive samples ended up with no specific strains being detected; the main bacteria strains in PCR were not different from ordinary culture results.(3) With bacterial culture as the gold standard, the detection sensitivity of PCR technology for PDAP pathogenic bacteria was 96.15% and specificity was 42.86%; the detection positive rate was significantly higher than ordinary culture method.(4) PCR technology for detecting pathogenic bacteria could produce results within 4-6 hours, while reported positive results in the traditional bacterial culture would take(77.88±15.53) hours, which was significantly longer than PCR. Conclusion Compared with traditional bacteria culture method, PCR method is more sensitive, simple, and quick. Bacteria detection using PCR technique is of clinic applied value in PDRP. Key words: Peritonitis; Peritoneal dialysis; Pathogenic bacteria; Polymerase chain reaction; Bacteria cultures