大肠杆菌密度感应调节子C在失血性休克大鼠肠道细菌移位中的作用

Role of quorum sensing Escherichia coil regulator C in intestinal bacterial translocation in rats subjected to hemorrhagic shock

目的评价大肠杆菌密度感应调节子C（qseC）在失血性休克大鼠肠道细菌移位中的作用。方法成年雄性SD大鼠30只，体重250—300g，采用随机数字表法，将大鼠随机分为5组（n=6）：对照组（C组）、MCl000．假休克组（M-SS组）、MCl000△qseC-假休克组（△-SS组）、MCl000．休克组（胁Hs组）和MCl000＆qseC-休克组（△-HS组）。大鼠连续3d饮用150gg／ml链霉素的消毒水溶液，抑制肠道内固有菌群；C组第4天开始，连续3d灌饲生理盐水（1ml／100g，1次／d），其余4组第4天开始，连续3d分别灌饲大肠杆菌MC1000或MCl000AqseC菌液（1ml／100g，1次，d）。采用左股动脉放血法制备失血性休克模型。手术结束后24h时采用链霉素抗性特点和菌落PCR技术对从内脏分离出的细菌进行鉴定；观察细菌移位情况和计数内脏组织细菌数。结果与c组比较，M—HS组和△-HS组大鼠细菌移位率、肠系膜淋巴结细菌含量、脾脏和肝脏菌落数和总菌落数均升高（P〈0．05）；与M．Ss组和△-SS组比较，M-HS组大鼠细菌移位率、肠系膜淋巴结细菌含量、脾脏和肝脏菌落数和总菌落数均升高（P〈0．05）；与M-HS组比较，△-HS组大鼠细菌移位率、肠系膜淋巴结、脾脏和肝脏菌落数和总菌落数均降低（P〈0．05）。结论大肠杆菌qseC参与了失血性休克大鼠肠道细菌移位的过程。

Objective To investigate the role of quorum sensing Escherichia coli regulator C （qseC） in intestinal bacterial translocation in rats subjected to hemorrhagic shock. Methods Thirty Sprague-Dawley rats, weighing 250-300 g, were randomly divided into 5 groups （ n = 6 each） ： control group （group C）, MC1000-sham shock group （group M-SS）, MClOOOqseC-shmn shock group （group △-SS）, MC1000-hemorrhagic shock group （group M-HS）, and MC1000A qseC-hemorrhagic shock group （group △-HS）. The rats drank 150 μg/ml of dis- infect water containing streptomycin in 3 consecutive days to inhibit the autochthonous flora in the intestinal tract. From 4th day, the rats were fed with Escherichia Coli MC1000 or MC1000△qseC 1 ml/100 g by gastric perfusion once a day for another 3 consecutive days in the other 4 groups, while the rats were fed with normal saline instead in group C. Hemorrhagic shock was induced by blood-letting. The mesenteric lymph node （MLN）, spleen and liver specimens were obtained at 24 h after operation for bacterial culture and the bacteria were identified. Bacterial translocatiun from gut to MLN, spleen and liver was observed and the number of bacteria in MLN, spleen and liver tissues were counted. Results The rate of bacterial translocation was significantly higher, and the number of bac- terial colonies in MLN, spleen and liver tissues and the total number of bacterial colonies were significantly larger in groups M-HS and △-HS than in group C, and in group M-HS than in groups M-SS and △-SS （P 〈 0.05）.The rate of bacterial translocation was significantly lower, and the number of bacterial colonies in MLN, spleen and liver tissues and the total number of bacterial colonies were significantly smaller in group △-HS than in group M- HS. Conclusion QseC is involved in the intestinal bacterial transiocation following hemorrhagic shock in rats.