急性坏死性胰腺炎并发感染的机理研究

目的观察急性坏死性胰腺炎时肠屏障损伤与细菌移位情况,探讨急性胰腺炎继发感染的机理。方法１５只犬于肠道内定植ＰＵＣ１８质粒菌ＪＭ１０９后,分对照组（ｎ＝７）和急性坏死性胰腺炎组（ＡＮＰ,ｎ＝８）。ＡＮＰ组经主胰管注入牛磺胆酸钠和胰蛋白酶制作ＡＮＰ模型。结果ＡＮＰ组较对照组血胰淀粉酶显著升高（Ｐ＜０．０１）;尿中乳果糖／甘露醇比值高出对照组２～１２倍;空、回、盲肠粘膜及肠内容物中大肠杆菌明显增加（Ｐ＜０．０１）,双歧杆菌、乳酸杆菌明显减少（Ｐ＜０．０１、Ｐ＜０．０５）。对照组犬血培养阴性,除２只犬肠系膜淋巴结培养出细菌外,其余脏器培养均阴性。ＡＮＰ组犬血和脏器细菌培养阳性率均为１００％,且每只犬都能检出术前定植于肠道的质粒菌ＪＭ１０９;胰腺腺泡出血、坏死;肠粘膜绒毛破坏;血浆、回肠组织二胺氧化酶活性下降。结论ＡＮＰ时肠粘膜屏障功能严重受损,发生肠道细菌移位,成为继发性胰腺感染的潜在根源。

The pathogenesis of infection complicated by acute necrotizing pancreatitis: an experimental study

OBJECTIVE: To observe the injury of gut barrier function and intestinal bacterial translocation following acute necrotizing pancreatitis (ANP), and to investigate the pathogenesis of infection complicated by ANP. METHOD: Fifteen dogs were colonized with a strain of E. coli JM109 bearing ampicillin-resistant plasmid PUC18, then divided into two groups: control group (n = 7) and ANP group (n = 8). Acute necrotizing pancreatitis was induced by injection of sodium taurocholate and trypsin into the pancreatic duct. RESULT: In the ANP group, as compared with the control group, serum amylase level increased significantly, the lactulose/mannitol ratio was 2-12 times higher, blood and ileum diamine oxidase activity decreased significantly. E. coli population in intestinal mucosal flora increased, while bifidobacterium and lactobacillus reduced significantly. Bifidobacterium/E. coli ratio was reversed. Morphological study revealed areas of hemorrhage and necrosis in the pancreas and shedding of ileal villi. In the control group, blood cultures were negative, and no organism was found in organs except for mesenteric lymph nodes in two dogs. In the ANP group, blood and organ cultures were positive in all dogs and JM109 could be found uniformly too. CONCLUSION: ANP impaired the gut barrier function, which led to bacterial translocation from the gut to the pancreas and other organs, serving as a primary source of infection secondary to ANP.