Intestinal damage in enterohemorrhagic Escherichia coli infection
Intestinal damage in enterohemorrhagic Escherichia coli infection
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DOI：
10.1007/s00467-010-1616-9
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发表时间：
2011-11-01
影响因子：
3
通讯作者：
Karpman, Diana
中科院分区：
文献类型：
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作者：
Bekassy, Zivile D.;Toledo, Carla Calderon;Karpman, Diana
肠出血性大肠埃希菌(EHEC)感染可导致明显的肠道损伤。2例肠出血性肠出血性肠炎患儿乙状结肠可见丰富的TUNEL阳性细胞。为了确定哪些细菌毒力因子与肠道损伤有关，志贺毒素-2(Stx2)、内膜和III型分泌系统的存在与症状和肠道损伤相关。将产Stx2(86-24)和不产Stx2(87-23)的O157：H7菌株和不编码EAE的86-24株突变株(UMD619株)或ESCN株(CVD451株)分别接种C3H/HEN小鼠。接种86-24和87-23的小鼠出现严重症状。接种了突变菌株的小鼠很少出现严重症状。菌株86-24的粪便细菌数量较多，其次是87-23，而菌株UMD619和CVD451的粪便细菌数量最少。接种86-24株的小鼠近端和远端结肠的TUNEL阳性细胞数明显多于87-23株和CVD451株(P<0.01)和UMD619株(P<；0.05，近端结肠，P<；0.01，远端结肠)。结果表明，86-24和87-23菌株表现出更好的结肠持久性和更多的症状，可能是由于存在内膜和III型分泌效应物。广泛的肠粘膜细胞死亡与Stx2的存在有关。
Enterohemorrhagic Escherichia coli (EHEC) infection leads to marked intestinal injury. Sigmoid colon obtained from two children during EHEC infection exhibited abundant TUNEL-positive cells. To define which bacterial virulence factors contribute to intestinal injury the presence of Shiga toxin-2 (Stx2), intimin and the type III secretion system were correlated with symptoms and intestinal damage. C3H/HeN mice were inoculated with Stx2-producing (86-24) and non-producing (87-23) E. coli O157:H7 strains and 86-24 mutants lacking eae, encoding intimin (strain UMD619) or escN regulating the expression of type III secretion effectors (strain CVD451). Severe symptoms developed in mice inoculated with 86-24 and 87-23. Few mice inoculated with the mutant strains developed severe symptoms. Strain 86-24 exhibited higher fecal bacterial counts, followed by 87-23, whereas strains UMD619 and CVD451 showed minimal fecal counts. More TUNEL-positive cells were found in proximal and distal colons of mice inoculated with strain 86-24 compared with strains 87-23 and CVD451 (p a parts per thousand currency signaEuro parts per thousand 0.01) or UMD619 (p < 0.05, proximal colon, p < 0.01, distal colon). The results show that strains 86-24 and 87-23 exhibited better colonic persistence and more symptoms, presumably due to the presence of intimin and type III secretion effectors. Extensive intestinal mucosal cell death was related to the presence of Stx2.