Unraveling novel broad-spectrum antibacterial targets in food and waterborne pathogens using comparative genomics and protein interaction network analysis

Food and waterborne diseases are a growing concern in terms of human morbidity and mortality worldwide, even in the 21st century, emphasizing the need for new therapeutic interventions for these diseases. The current study aims at prioritizing broad-spectrum antibacterial targets, present in multiple food and waterborne bacterial pathogens, through a comparative genomics strategy coupled with a protein interaction network analysis. The pathways unique and common to all the pathogens under study (viz., methane metabolism, d-alanine metabolism, peptidoglycan biosynthesis, bacterial secretion system, two-component system, C5-branched dibasic acid metabolism), identified by comparative metabolic pathway analysis, were considered for the analysis. The proteins/enzymes involved in these pathways were prioritized following host non-homology analysis, essentiality analysis, gut flora non-homology analysis and protein interaction network analysis. The analyses revealed a set of promising broad-spectrum antibacterial targets, present in multiple food and waterborne pathogens, which are essential for bacterial survival, non-homologous to host and gut flora, and functionally important in the metabolic network. The identified broad-spectrum candidates, namely, integral membrane protein/virulence factor (MviN), preprotein translocase subunits SecB and SecG, carbon storage regulator (CsrA), and nitrogen regulatory protein P-II 1 (GlnB), contributed by the peptidoglycan pathway, bacterial secretion systems and two-component systems, were also found to be present in a wide range of other disease-causing bacteria. Cytoplasmic proteins SecG, CsrA and GlnB were considered as drug targets, while membrane proteins MviN and SecB were classified as vaccine targets. The identified broad-spectrum targets can aid in the design and development of antibacterial agents not only against food and waterborne pathogens but also against other pathogens.     

深圳市某村一起水源性诺如病毒感染性胃肠炎暴发的调查

目的了解某村一起感染性腹泻暴发的特点和流行原因,探讨暴发疫情调查处理的经验并为制定防治对策提供科学依据。方法 采用现场流行病学调查分析和实验室检测方法。结果10月24-30日,该村发生感染性腹泻病例96例,罹患率为9.2%,最小2月龄,最大86岁,男女性别比为1.1：1,居家病例呈一定的家庭聚集性,病例的临床表现基本相同,以腹泻、腹痛、恶心、呕吐和发热等症状为主,病程1~3 d。病例对照研究显示,饮用山泉水和饭前用山泉水冲洗碗筷为危险因素。从病人粪便标本中和管网末梢水中检测到诺如病毒抗原,采取改用市政水、隔离治疗病人和健康教育等综合措施后,疫情迅速得到控制。结论本次疫情为一起诺如病毒感染性腹泻暴发,暴发原因是该村供水系统被污染。供水系统安全存在诸多薄弱环节,建议尽快改用市政自来水供水。     

新疆和田县改水综合效益评估与量化分析

目的 对新疆和田县改水综合效益进行评估及量化分析。方法 回顾了和田县1992－1998年介水传染病（痢疾、肝炎、伤寒和霍乱）发病情况，健康教育成果，对取水负担的减轻和医药费用的节约做了量化分析。结果 改水受人口占和田县总人口95％，和田县1992－1998年介水传染病发病率除痢疾均呈下降趋势，群众卫生知识水平提高，养成良好的卫生习惯；截止到2000年累计改水投资4550万元，累计节约取水负担费用1864－4246万元，累计节约医药费用660万元，兴建水厂效益291万元，庭院经济效益3556万元，直接经济效益6731万元－8752万元。结论 和田县改水工程具有显著的社会效益和经济效益，其经济效益明显超出总投资规模。     

高碘地区儿童碘营养影响因素和甲状腺肿大及结节的流行特征

目的了解高碘地区停供碘盐前儿童碘营养的影响因素和甲状腺肿大和结节的状况。方法采用单纯随机法在河北省衡水市水碘中位数在200～300μg/L高碘乡(镇)中随机抽取3个进行调查。结果在3个乡(镇)共采集测定8～10岁儿童1次即时尿样326份,尿碘中位数在478.4～571.3μg/L之间,尿碘含量>300μg/L尿样所占比例在77.9%～86.6%之间。12个村儿童的尿碘中位数与其所在村的水碘中位数成正相关(Spearsman,R=0.79,P=0.002),而与盐碘中位数不相关(Spearsman,R=-0.17,P=0.6)。儿童尿碘中位数与水碘中位数成直线相关(R=0.83,F=22.0,P=0.001),直线回归方程为:尿碘=318.1+0.829*水碘。在3个乡(镇)共用B超检测8～10岁儿童452名,甲状腺肿大37例,肿大率为8.2%;不同性别和年龄组甲状腺肿大率无显著差异。在其中2个乡共发现甲状腺结节15例,平均检出率为5.6%,不同性别和年龄组甲状腺结节检出率无显著差异。结论高碘地区儿童碘营养过剩主要由高水碘造成,碘盐加重了这种状况;存在甲状腺肿大流行,甲状腺结节的检出率也较高。甲状腺结节的成因和发生强度有待于进一步研究。     

Edwardsiella tarda bacteremia. A rare but fatal water- and foodborne infection: Review of the literature and clinical cases from a single centre

BACKGROUND:Edwardsiella tarda bacteremia (ETB) can be a fatal disease in humans.OBJECTIVES:To determine the significant risk factors associated with death caused by ETB, and to examine the geographical, seasonal, environmental and dietary factors of the disease.METHODS:A retrospective, observational, case control study was performed. The PubMed MEDLINE and Japanese Medical Abstract Society (www.jamas.or.jp) databases were searched for ETB case reports and meeting abstracts. In additon, retrospective chart reviews of patients with ETB at the Tokyo Women’s Medical University Hospital (Tokyo, Japan) were conducted to evaluate the risk factors associated with death using multivariate analyses.RESULTS:The literature search yielded 46 publications, comprising 72 cases from the English (n=30), French (n=1), Spanish (n=1) and Japanese (n=14) literature. Five cases at the Tokyo Women’s Medical University Hospital were also included. Of the included 77 cases, the mean age was 61 years and 39% of patients were female; 77.2% of the cases occurred between June and November, and 45.5% were reported in Japan. Dietary factors (raw fish/meat exposure) were reported for 10.4% of patients and 12.9% reported environmental (ie, brackish water) exposure. The overall mortality rate was 44.6%; however, this rate increased to 61.1% for ETB patients with soft tissue infections. Liver cirrhosis was determined to be an independent risk factor associated with death (OR 12.0 [95% CI 2.46 to 58.6]; P=0.00213) using multivariate analyses.DISCUSSION:To our knowledge, the present analysis was the first and largest multi-language review of ETB. Clinical characteristics of ETB resemble those of Aeromonas, typhoid fever and Vibrio vulnificus infections, in addition to sharing similar risk factors.CONCLUSION:ETB should be categorized as a severe food- and waterborne infection, which results in high mortality for patients with liver cirrhosis.     

南充市区水质与水性传染病调查研究

本文对南充市两自来水公司１９９５～１９９６年水源水、出厂水和管网水监测结果作了分析，结果表明，供水的感官性状及部分一般化学指标、细菌学指标是构成水质不合格的主要原因，其前三位指标为浑浊度、游离性余氯、总大肠菌群、超标率分别为５０．７４％、１８．３４％、５．３３％。毒理学指标符合ＧＢ５７４９－８５规定限量。水源水质符合规定标准要求。各类水样均检出三卤甲烷类化合物（ＴＨＭｓ）。与水有关传染病９６年较９５年明显增高，统计学上有非常显著性差异（Ｐ＜０．００１）。     

Epidemiological explanation of an outbreak of gastro-enteritis in Sweden in the absence of detailed microbiological information

Waterborne gastroenteritis outbreaks have often gone undetected or been incompletely defined in terms of source and extent. Methods which allow detection or clarification of such events are therefore useful. We describe the methods used to detect and investigate such an outbreak. In autumn 1996 high school absence rates and the rate of parents absent from work to care for sick children suggested a health problem in a Swedish town which had a history of unexplained outbreaks of gastrointestinal disease. A systematic sample of 300 households was surveyed by post. Respondents represented 10% of the total population of the town. Questions concerning symptoms and exposures were included. The same questionnaire was used in a nearby town as a control. Sixty four percent of respondents reported an acute gastrointestinal illness during a two month period. Diarrhoea (90%) and abdominal pain (88%) were the most frequent symptoms among the sick. Two percent of those sick sought medical care. Exposures associated with disease were being a member of a large household, young age, and consumption of water from the community water supply. Attack rate showed a dose response relationship with increasing frequency of water consumption. The peak incidence of gastrointestinal illness occurred shortly after raw water quality control data had shown a rise in indicator bacteria. Further analysis, dividing those infected into groups according to when they became ill and whether they were the first member of their household to fall ill, supported the hypothesis of primary cases being infected from the water supply with some secondary person to person spread.