Survival and pathogenicity of Clostridioides difficile in sewage, sewage sludge, surface water, animal manure, fodder, crops and silage -Treatment requirements to minimize health risks" (SUPER safe)

污水、污水污泥、地表水、动物粪便、饲料、农作物和青贮饲料中艰难梭菌的生存和致病性-最小化健康风险的处理要求”（超级安全）

• 批准号: 423210466
• 负责人: Professorin Dr. Claudia Gallert
• 金额: --
• 依托单位: Fachbereich Technik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/423210466?language=en
• 关键词: Survival; pathogenicity; Clostridioides; difficile; sewage

The Gram-positive, anaerobic endospore forming Clostridioides difficile is the major cause of nosocomial infectious diarrhoea in humans and livestock. C. difficile infection (CDI) is a toxin-mediated intestinal disease and occurs when the natural flora in the guts is disrupted by antibiotics. The hypervirulent nosocomial pathogen C. difficile is a burden for health care systems worldwide and, as an emerging pathogen C. difficile is a major matter of discussion in infection prevention and control. Treatment of CDI is hampered by C. difficile endospores which can persist antibiotic treatment in the guts, rapidly repopulate guts with vegetative cells and lead to recur of an infection. As a colonizer of the intestine C. difficile cells and spores could be excreted and found in feces of humans and animals. For this reason C. difficile can be clearly associated with feces. It is expected that C. difficile can be found in sewage, sewage sludge and animal manures as well and in other sources which could be contaminated with feces like surface water or fodder. Since there is a rising importance of anaerobic digestion AD for sewage sludge and animal manure treatment, attention should focus on survival and multiplication of C. difficile during AD and increasing release into the environment by anaerobic manure and wastewater treatment systems and utilization of residues as fertilizers.The aim of the proposed research project is thus to identify environmental sources with a high prevalence of C. difficile. Enumeration and isolation of environmental C. difficile and further characterization of the toxigenic potential by analyzing e.g. genes for production of Toxin A or B and the binary toxin CDT is intended. Beside ribotyping, antibiotic susceptibility testing for determination of MIC and determination of respective antibiotic resistance genes and conjugative transposons present in isolated environmental strains should give information about epidemiological behavior. By establishing qPCR for enumeration of C. difficile cells and the conjugative transposon Tn5397 cell counts and pathogenicity of C. difficile in fecal-associated samples will be quantified. Since a large number of anaerobic digestors were installed in past years for treatment of sludge and manure, AD of sewage sludge and cattle manure will be simulated in lab-reactors to investigate survival or even growth or the reduction/elimination of C. difficile in terms of cell numbers and the conjugative plasmid outside of the cells. Such tests will include long term manure storage and ozonation and UV disinfection procedures, final treatment steps for sewage. By strengthening research in the field of microbiology and environmental engineering the anticipated work program should deliver results and extend knowledge on survival and the pathogenic potential of C. difficile in “fecal-associated” samples and allow to draw conclusions on transmission ways and to assess the health risk for human and animals.

形成艰难梭菌的革兰氏阳性厌氧内生孢子是人类和牲畜医院感染性腹泻的主要原因。C.艰难梭菌感染（CDI）是一种毒素介导的肠道疾病，当肠道中的天然植物群被抗生素破坏时发生。高致病力的医院病原体C。艰难梭菌是全球卫生保健系统的负担，并且作为一种新兴的病原体C。艰难梭菌是感染预防和控制中讨论的主要问题。CDI的治疗受到C.艰难的内生孢子，其可以在肠道中持续抗生素治疗，用营养细胞快速地重新填充肠道并导致感染复发。作为肠道的殖民者C.艰难梭菌的细胞和孢子可以排出体外，并在人和动物的粪便中发现。因此，C。艰难梭菌可明显与粪便相关。预计C.艰难梭菌可以在污水、污水污泥和动物粪便中发现，也可以在其他可能被粪便污染的来源中发现，如地表水或饲料。随着厌氧消化技术在城市污泥和畜禽粪便处理中的重要性日益提高，厌氧消化中C.艰难梭菌在AD期间和增加释放到环境中的厌氧粪肥和废水处理系统和利用残留物作为肥料。很难 环境C.艰难梭菌，并通过分析例如产生毒素A或B和二元毒素CDT的基因来进一步表征致突变潜力。除了核糖分型，抗生素敏感性测试，以确定MIC和确定各自的抗生素耐药基因和接合转座子存在于孤立的环境菌株应提供有关流行病学行为的信息。通过建立qPCR方法对C.艰难梭菌细胞和接合转座子Tn 5397细胞计数和致病性。将定量粪便相关样品中的艰难梭菌。由于近年来大量的厌氧反应器被安装用于污泥和粪便的处理，因此将在实验室反应器中模拟污水污泥和牛粪的AD，以研究C的存活甚至生长或减少/消除。艰难梭菌在细胞数量和接合质粒的细胞外。这些测试将包括长期粪便储存和臭氧化和紫外线消毒程序，污水的最终处理步骤。通过加强微生物学和环境工程领域的研究，预期的工作计划应取得成果，并扩大对C.在“粪便相关”样本中检测艰难梭菌，并允许得出传播途径的结论，评估人类和动物的健康风险。