Jackson R J, Smith S D, Wadowsky R M, DePudyt L, Rowe M I
University of Pittsburgh School of Medicine, PA.
J Pediatr Surg. 1991 Apr;26(4):483-5; discussion 485-6. doi: 10.1016/0022-3468(91)91000-o.
In the surgical neonate, three factors that promote bacterial translocation and systemic infection are: (1) intestinal bacterial colonization and overgrowth; (2) compromised host defenses; and (3) disruption of the mucosal epithelial barrier. The newborn rabbit provides an excellent model to study these factors. Like the human, there is early closure of the gut mucosa to macromolecules, and nutrition can be maintained by breast or formula feeding. This study examines translocation and systemic sepsis after colonization with virulent K1 and avirulent K100 strains of Escherichia coli. New Zealand white rabbit pups (2 to 5 days old) were studied. The gastrointestinal tracts of 12 were colonized with K1 E coli; 14 were colonized with K100 E coli; 12 control animals were not inoculated. Mesenteric lymph node (MLN), liver, spleen, and colon homogenate were cultured 72 hours postinoculation. No bacteria were isolated from the colons of all but one control animal. Translocation or systemic sepsis did not occur. Translocation to the MLN was significantly increased (P less than .03) in K1 (50%) and K100 (36%) groups compared with controls (0%). Translocation to liver and spleen (systemic sepsis) was significantly increased (P less than .03) in K1 animals (67%) compared with K100 (0%) or controls (0%). Colonization by both strains of E coli led to translocation to the MLN, but only K1 E coli caused systemic sepsis. This suggests that although colonization by E coli in the newborn leads to translocation to the MLN, progression to systemic sepsis is the result of characteristics of the bacteria and/or neonatal host responses.
在外科新生儿中，促进细菌易位和全身感染的三个因素是：（1）肠道细菌定植和过度生长；（2）宿主防御功能受损；（3）粘膜上皮屏障破坏。新生兔是研究这些因素的理想模型。与人类一样，肠道粘膜对大分子的早期封闭，并且可以通过母乳喂养或配方奶喂养维持营养。本研究检查了用强毒力K1和无毒力K100大肠杆菌菌株定植后的易位和全身败血症情况。研究了新西兰白兔幼崽（2至5日龄）。12只动物的胃肠道用K1大肠杆菌定植；14只用K100大肠杆菌定植；12只对照动物未接种。接种后72小时培养肠系膜淋巴结（MLN）、肝脏、脾脏和结肠匀浆。除一只对照动物外，所有动物的结肠均未分离出细菌。未发生易位或全身败血症。与对照组（0%）相比，K1组（50%）和K100组（36%）向MLN的易位显著增加（P<0.03）。与K100组（0%）或对照组（0%）相比，K1动物（67%）向肝脏和脾脏的易位（全身败血症）显著增加（P<0.03）。两种大肠杆菌菌株的定植均导致向MLN的易位，但只有K1大肠杆菌引起全身败血症。这表明，虽然新生儿中大肠杆菌的定植会导致向MLN的易位，但进展为全身败血症是细菌特征和/或新生儿宿主反应的结果。
