Michail Sonia, Abernathy Frank
Wright State University of Medicine and The Children's Medical Center, Sayton, Ohio 45504, USA.
J Pediatr Gastroenterol Nutr. 2002 Sep;35(3):350-5. doi: 10.1097/00005176-200209000-00021.
Enteropathogenic (EPEC) is a Gram-negative bacillus that causes diarrhea. Secretory responses of intestinal epithelial cells can be seen after EPEC infection. Probiotics, which are live bacteria that have proven benefit to the host, play a role in the treatment and prevention of the different enteric pathogens. The goals of the study were to determine whether the probiotic agent (LBP) strain 299v alters the secretory changes seen in EPEC infection and, if so, what underlying mechanism is possible.
Caco-2 cell monolayers were rapidly infected with EPEC strain E2348/69 and immediately mounted in Ussing chambers. The monolayers were exposed to LBP before, after, and simultaneously with EPEC infection. Short circuit current (Isc) was measured in the Ussing chamber.
EPEC infection caused an increase in short circuit current that was reduced by preincubation with LBP ( < 0.01). No direct bactericidal effect was observed, but LBP reduced the attachment of EPEC to Caco-2 cells.
LBP can play an important role in reducing the secretory change in response to EPEC infection, possibly through inhibition of its binding. However, the presence of the probiotic agent before the infection is necessary. In this setting, its role is more preventive rather than therapeutic.
肠致病性大肠杆菌(EPEC)是一种可导致腹泻的革兰氏阴性杆菌。EPEC感染后可观察到肠道上皮细胞的分泌反应。益生菌是已被证实对宿主有益的活菌,在治疗和预防不同肠道病原体方面发挥作用。本研究的目的是确定益生菌制剂(LBP)菌株299v是否会改变EPEC感染时出现的分泌变化,如果会,可能的潜在机制是什么。
用EPEC菌株E2348/69快速感染Caco-2细胞单层,并立即安装在尤斯灌流小室中。在EPEC感染之前、之后以及同时将单层细胞暴露于LBP。在尤斯灌流小室中测量短路电流(Isc)。
EPEC感染导致短路电流增加,而预先用LBP孵育可使其降低(<0.01)。未观察到直接杀菌作用,但LBP减少了EPEC对Caco-2细胞的附着。
LBP可能通过抑制EPEC的结合,在减少EPEC感染引起的分泌变化方面发挥重要作用。然而,感染前存在益生菌制剂是必要的。在这种情况下,其作用更多的是预防性而非治疗性。