Laboratorio de Fisiopatogenia, Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
Infect Immun. 2013 Aug;81(8):2931-7. doi: 10.1128/IAI.00287-13. Epub 2013 Jun 3.
Shiga toxin-producing Escherichia coli O157:H7 (STEC) is by far the most prevalent serotype associated with hemolytic uremic syndrome (HUS) although many non-O157 STEC strains have been also isolated from patients with HUS. The main virulence factor of STEC is the Shiga toxin type 2 (Stx2) present in O157 and non-O157 strains. Recently, another toxin, named subtilase cytotoxin (SubAB), has been isolated from several non-O157 strains and may contribute to the pathogenesis of HUS. Here, we have demonstrated that an O113:H21 STEC strain expressing SubAB and Stx2 inhibits normal water absorption across human colon and causes damage to the surface epithelium, necrosis, mononuclear inflammatory infiltration, edema, and marked mucin depletion. This damage was less marked, but nevertheless significant, when purified SubAB or E. coli O113:H21 expressing only SubAB was assayed. This is the first study showing that SubAB may directly participate in the mechanisms of diarrhea in children infected with non-O157 STEC strains.
产志贺毒素大肠杆菌 O157:H7（STEC）是迄今为止与溶血性尿毒综合征（HUS）相关的最常见血清型，尽管许多非 O157 STEC 菌株也从 HUS 患者中分离出来。STEC 的主要毒力因子是存在于 O157 和非 O157 菌株中的志贺毒素 2 型（Stx2）。最近，一种名为枯草杆菌蛋白酶细胞毒素（SubAB）的毒素已从几种非 O157 菌株中分离出来，可能有助于 HUS 的发病机制。在这里，我们证明了表达 SubAB 和 Stx2 的 O113:H21 STEC 菌株抑制了人结肠的正常水吸收，并导致表面上皮损伤、坏死、单核炎性浸润、水肿和明显的粘蛋白耗竭。当仅表达 SubAB 的纯化 SubAB 或 E. coli O113:H21 进行检测时，这种损伤虽然不那么明显，但仍然具有统计学意义。这是第一项表明 SubAB 可能直接参与感染非 O157 STEC 菌株的儿童腹泻机制的研究。
