PCR检测细菌DNA对大鼠结肠吻合口漏的早期诊断

Early diagnosis of colonic anastomotic leakage by detecting bacterial DNAs in rats with PCR

目的探讨PCR检测大鼠血液中细菌DNA对结肠吻合口漏的早期诊断价值。方法健康Wistar雌性大鼠48只，随机分成：A组（n=8）为假手术组；B组（n=20）为结肠-结肠吻合组；C组（n=20）为结肠吻合口漏组；采集手术前后外周血，抽提DNA，比较PCR检测大肠杆菌lacZ基因和细菌共有的16SrRNA基因的PCR阳性率，并观察各组的病理学情况。结果C组外周血lacZ基因的PCR阳性率显著高于B组（P〈0．05）；C组外周血16SrRNA基因的PCR阳性率与B组差异无统计学意义（P〉0．05）。结论PCR检测术后外周血lacZ基因对结肠吻合口漏的诊断可能有一定的意义，而检测术后外周血16SrRNA基因对结肠吻合口漏的意义可能不大。

Objective To asses the value of detecting bacterial DNAs in rats blood with PCR for early diagnosis of colonic anastomotic leakage. Methods 48 healthy female Wistar rats were random divided into three groups： Group A （ n =8, sham operation group）, Group B （ n = 20, colonic anastomosis group） , Group C （ n = 20, colonic anastomotic leakage group）. Group B and C rats underwent standardized colon resection 3cm away from the ileocecal junction 10cm, Group B rats were done with a complete anastomosis （end-to-end single layer anastomosis with 0# silk sutures） while Group C rats were done with an anastomosis leaving a 5mm opening in colonic anterior wall. 1 ml and 3 ml venous blood samples were collected from Group A, B and C. DNAs were extracted from these blood samples and PCR techniques were used to amplify lacZ genes from Escbericbia coli and 16S ribosomal RNA genes （16SrRNA genes） 3 days after operation. The data were analyzed by cbi square test. Specimens of the experimental intestine were HE stained for pathological studies. Results The positive ratios of expressing lacZ genes in peripheral blood （PB） with PCR in Group C were significantly higher than that in Group B （ P 〈 0. 05 ）, but there were no differences between the two groups in expressing 16SrRNA genes （ P 〉 0. 05 ）. Conclusions It could be a useful way to detect lacZ genes of Escbericbia coli from PB by PCR but not 16SrRNA genes for diagnosis of colonic anastomotic leakages.