enterohemorrhagic Escherichia coli

肠出血性大肠杆菌
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    文章类型: Journal Article
    大肠杆菌是革兰氏阴性杆菌,根据菌株的不同,被认为是肠道和肠外表现的正常病原体。存在引起无数临床表现的多种菌株。大肠杆菌O157:H7是最常见和最严重的细菌病原体,是血性腹泻的主要原因。肠出血性大肠杆菌(EHEC)是导致严重并发症的原因,如HC(出血性结肠炎)。在这里,我们介绍了一例年轻女孩感染大肠杆菌O157:H7的病例,并复习了相关文献。一名健康的37岁女性出现血性腹泻,发烧,头痛,和下腹部疼痛。根据历史,她吃过一个汉堡包,否认有任何近期旅行和家族病史中没有炎症性肠病或血便.体格检查显示生命体征正常,除严重腹痛外,体格检查无明显变化。她的大便隐窝呈阳性。除嗜中性粒细胞增多和白细胞增多外,全血细胞计数均在正常范围内。腹部超声显示与结肠炎一致的肠loop增厚。她住院的第一周,她继续出现血性腹泻和严重的腹痛。她在第7天提交给实验室的最终粪便与血凝块一致,在她出现低尿量和血尿后,第5天血清肌酐为2.1mg/dl。她的肾脏症状用液体治疗。她得到了支持治疗,血小板计数和血红蛋白稳定.在血性腹泻的早期阶段,父母水合作用在加速体积膨胀中起主要作用。这些细菌的快速粪便分析可以提醒专家处理HUS等严重并发症。
    Escherichia coli is a gram-negative bacillus and considered to be the normal pathogen of intestinal and extraintestinal manifestations depending upon the strain. A variety of strains exist that are responsible for causing myriads of clinical presentation. E.coli O157: H7 being the most common and severe bacterial pathogen is the leading cause of bloody diarrhea. EHEC (Enterohemorrhagic E.coli) is responsible for causing severe complications like HC (Hemorrhagic colitis). Herein, we present the case of a young girl with E.coli O157:H7 infection and review the related literature. A previously healthy 37-year-old female presented with bloody diarrhea, fever, headache, and lower abdominal pain. As per history she had eaten a hamburger, denied any recent travel and absence of inflammatory bowel disease or bloody stools in family history. Physical examination revealed normal vital signs and the physical findings were unremarkable except for severe abdominal pain. Her stool was hem-occult positive. The complete blood count was within normal limits except neutrophilia and leukocytosis. An abdominal ultrasound showed thickened bowel loops consistent with colitis. First week of her hospital course, she continued to have bloody diarrhea and severe abdominal pain. Her final stool submitted to the laboratory on day 7 was consistent with a blood clot, following her developed low urine output and hematuria, with a serum creatinine of 2.1 mg/dl on day 5. Her renal symptoms were treated with fluids. She was given supportive treatment, and her platelet count and hemoglobin were stabilized. In early stages of bloody diarrhea, parental hydration plays a major role in accelerating volume expansion. Rapid stool analysis for these bacteria can alert specialists to deal with severe complications like HUS.
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  • 文章类型: Journal Article
    Enterohemorrhagic Escherichia coli (EHEC) and Salmonella enterica have been implicated in several disease outbreaks linked to consumption of fresh vegetables. Both ruminant and non-ruminant animals carry EHEC and S. enterica in their gastrointestinal tracts and can shed the pathogens in the faecal matter both in symptomatic and asymptomatic states. Application of animal waste in soil fertility management and irrigation of crops with contaminated waste water has been recognised as an important route through which EHEC and S. enterica can contaminate fresh vegetables during primary production. The behavior of E. coli O157:H7 and S. enterica in the agricultural environment has been extensively studied in the last decades. Several microbiological detection methods have been applied. This review therefore puts together current knowledge on the behavior of E. coli O157:H7 and S. enterica in the manure-amended soil-plant ecosystem of fresh vegetable crops during cultivation under various environmental conditions. The review focuses on methodological issues involved in undertaking survival studies and makes comparative analysis of experimental results obtained from studies conducted under controlled environmental conditions integrating results obtained from field experiments. Finally, a theoretical discussion on the potential likely impact of climate change on pre-harvest safety of field-cultivated vegetables is highlighted.
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  • 文章类型: Journal Article
    背景:布拉氏酵母菌,一种经过充分研究的益生菌,可以有效治疗具有多种病理生理学的炎症性胃肠道疾病,如炎症性肠病(IBD),以及细菌介导的或肠毒素介导的腹泻和炎症。
    目的:探讨布拉氏球菌肠道抗炎作用的作用机制。
    方法:回顾与该益生菌的抗炎作用相关的文献。
    结果:已经确定了针对宿主和病原微生物的几种作用机制。布拉氏链球菌和布拉氏链球菌分泌蛋白通过干扰炎症核因子κB的整体介质来抑制促炎细胞因子的产生,和调节丝裂原活化蛋白激酶ERK1/2和p38的活性。布拉氏链球菌激活过氧化物酶体增殖物激活受体-γ(PPAR-γ)的表达,防止肠道炎症和IBD。布拉氏链球菌还抑制“细菌过度生长”和宿主细胞粘附,释放一种蛋白酶,该蛋白酶切割艰难梭菌毒素A及其肠受体,并刺激针对毒素A的抗体产生。最近的结果表明,布拉氏链球菌可能通过将T细胞捕获在肠系膜淋巴结中来干扰IBD的发病机理。
    结论:布拉氏链球菌发挥的多种抗炎机制提供了分子解释,支持其在肠道炎症状态中的有效性。
    BACKGROUND: Saccharomyces boulardii, a well-studied probiotic, can be effective in inflammatory gastrointestinal diseases with diverse pathophysiology, such as inflammatory bowel disease (IBD), and bacterially mediated or enterotoxin-mediated diarrhoea and inflammation.
    OBJECTIVE: To discuss the mechanisms of action involved in the intestinal anti-inflammatory action of S. boulardii.
    METHODS: Review of the literature related to the anti-inflammatory effects of this probiotic.
    RESULTS: Several mechanisms of action have been identified directed against the host and pathogenic microorganisms. S. boulardii and S. boulardii secreted-protein(s) inhibit production of proinflammatory cytokines by interfering with the global mediator of inflammation nuclear factor kappaB, and modulating the activity of the mitogen-activated protein kinases ERK1/2 and p38. S. boulardii activates expression of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) that protects from gut inflammation and IBD. S. boulardii also suppresses \'bacteria overgrowth\' and host cell adherence, releases a protease that cleaves C. difficile toxin A and its intestinal receptor and stimulates antibody production against toxin A. Recent results indicate that S. boulardii may interfere with IBD pathogenesis by trapping T cells in mesenteric lymph nodes.
    CONCLUSIONS: The multiple anti-inflammatory mechanisms exerted by S. boulardii provide molecular explanations supporting its effectiveness in intestinal inflammatory states.
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  • 文章类型: Journal Article
    在临床试验中记录了牛初乳作为生物制剂的价值,并得到了包含病例报告和轶事发现的相对较大的数据库的支持。主要作用包括抗菌作用和免疫反应的调节。牛初乳浓缩物(BCC是由几只母牛的初乳产生的多价牛初乳浓缩物)中和脂多糖的能力,即由革兰氏阴性细菌病原体引起的内毒素和在动物模型中抑制肠源性内毒素血症,如上次综述中所示,在患者治疗中具有其对应物。BCC的临床试验提供了证据,表明口服可减少LPS从肠道的流入,这似乎是其对有革兰氏阴性脓毒性休克风险的患者的治疗作用的主要机制;来自两项控制良好的临床研究的数据,共有100名手术患者表明,应用BCC后对肠道LPS吸收的抑制作用不仅降低了外周血中的LPS水平,而且发现IL-6和CRP等炎症参数也降低。市售BCC制剂的常规日剂量,LactobinA(LC1)是每天10-20克,但是由于不耐受问题的发生率低,大多数患者可以使用更高的剂量。在涉及严重形式的继发性免疫缺陷的慢性腹泻中,接受LC1治疗的患者在约4周内无病,但AIDS患者的反应可能较低.BCC对因肠出血性大肠杆菌感染引起的出血性腹泻的婴儿有效,并降低了疾病发展为溶血性尿毒综合征的可能性。从无疯牛病的地区获得的较新的BCC产品的安全性现在似乎没有争议。以LC1为例,直到1992年,它在德国一直被用作商业饮食食品,并在三项1期和5期临床研究中进行了测试(两项针对继发性免疫缺陷患者的试验,一名患有胃肠道疾病的外科患者,一名接受心脏直视手术的患者和一名患有EHEC感染的儿科患者),没有BSE相关疾病的病例,例如新变种的Creutzfeldt-Jakob病。临床相关的副作用限于对乳糖的可能不耐受和对乳蛋白的敏感性,因为这些也存在于许多常用的食品中。已在BCC中观察到与常规药物疗法的重要协同作用,包括用杀菌抗生素治疗的革兰氏阴性细菌感染患者的LPS血浆水平降低。在健康人中,外周血中只能检测到低浓度的LPS(正常值:3±10pg/ml血浆,即大约0.1EU/ml)。相比之下,浓度>300pg/ml的全身水平升高在严重革兰氏阴性脓毒症和脓毒性休克患者中很常见.LPS水平升高主要发生在已经用杀菌抗生素治疗的革兰氏阴性菌感染患者中。BCC降低LPS的作用可能是由于BCC中存在许多活性成分,这些成分起源于其生物来源的先天体液和适应性免疫系统。牛。
    The value of bovine colostrum as a biologic in medicine is documented in clinical trials and supported by relatively large databases containing case reports and anecdotal findings. The main actions include an antibacterial effect and modulation of the immune response. The ability of bovine colostrum concentrates (BCC are polyvalent bovine colostrum concentrates produced from the colostrums of several 100 cows) to neutralize lipopolysaccharides, i.e. endotoxins arising from Gram-negative bacterial pathogens and to inhibit enterogenic endotoxemia in animal models as shown in the last review to have its counterpart in patient therapy. Clinical trials with BCC provide evidence that oral application reduces the influx of LPS from the gut and this appears to be a major mechanism underlying its therapeutic effect in patients at risk for Gram-negative septic shock; data from two well-controlled clinical studies with a total of 100 surgical patients have shown that the inhibition of intestinal LPS absorption measured after the application of BCC not only reduced the LPS levels in the peripheral blood but also inflammatory parameters like IL-6 and CRP were found to be diminished. The usual daily dose of the commercially available BCC preparation, LactobinA (LC1) is 10 â 20 g daily, but higher doses can be used in the majority of patients because of the low incidence of intolerance problems. In chronic diarrhea involving severe forms of secondary immunodeficiencies, patients receiving LC1 were disease-free for about 4 weeks but the response may be lower in patients with AIDS. BCC is effective in infants with hemorrhagic diarrhea caused by infections with enterohemorrhagic E. coli and reduces the likelihood of the disease progressing to a hemolytic uremic syndrome. The safety of newer BCC products obtained from BSE-free regions seems now beyond contention. In the case of LC1, which was used as a commercial dietary foodstuff in Germany until 1992 and tested in three Phase 1 and 5 clinical studies (two trials in patients with secondary immunodeficiencies, one in surgical patients with gastrointestinal disorders, one in patients undergoing open heart surgery and one in pediatric patients with EHEC infections), there were no cases of BSE-associated disease such as the new variant of Creutzfeldt-Jakob disease. Side effects of clinical relevance are limited to possible intolerance to lactose and sensitivity to milk proteins as these are also present in many commonly used foodstuffs. Important synergistic actions with conventional drug therapies have been observed with BCC including a reduction in LPS plasma levels in patients with Gram-negative bacterial infections treated with bactericidal antibiotics. In healthy persons there are only small concentrations of LPS detectable in peripheral blood (normal values: 3 â 10 pg/ ml plasma, i.e. approximately 0.1 EU/ml). In contrast, elevated systemic levels with concentrations > 300 pg/ml are common in patients with severe Gram-negative sepsis and septic shock. Raised LPS levels occur mainly in patients with Gram-negative bacterial infections who have been treated with bacteriocidal antibiotics. The LPS-lowering effects of BCC are probably due to the numerous active components present in BCC which have their origin in the innate humoral and adaptive immune system of their biologic source, the cow.
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