浑河(抚顺段)水质粪大肠菌群污染现状研究

近年来,随着城市垃圾、生活污水、工业废水、人畜粪便和医院废水等的不合理排放,导致浑河(抚顺段)水质受到严重污染.粪大肠菌群(Fecal Coliform)是检验水质污染的一个重要生物指标,主要来源于人和混血动物的粪便,对水域进行粪大肠菌群的检测并结合理化分析,可以准确定出水体污染的性质和程度,从而可为水体的污染状况和程度的评估提供科学的依据.本文以粪大肠菌群作为水质粪便污染指标,于2005年监测了浑河(抚顺段)水体粪便污染情况,同时监测了水质COD值.其结果表明,浑河(抚顺段)水体粪便污染严重,粪大肠菌群与COD呈现良好的相关关系.     

安徽省畜禽粪便污染耕地、水体现状及其风险评价

以安徽省耕地、水体的环境保护为出发点,依据2001～2009年安徽省畜禽养殖数据,采用排泄系数法估算畜禽粪便量,在此基础上计算安徽省各地畜禽粪便耕地污染负荷及水体等标污染负荷指数,并对各地区畜禽粪便对耕地和水环境的污染现状进行风险评价.结果表明,2008～2009年安徽省平均产生0.67亿t粪便,畜禽粪便耕地污染负荷及纯N、纯P耕地负荷量平均值分别为16.2 t.hm-2、83.8 kg.hm-2和34.5 kg.hm-2;耕地污染指数为0.36,处于Ⅰ级预警级别范围;水环境等标污染负荷指数为7.03,各地区畜禽粪便对耕地和水环境污染存在较大差异.2008～2009年与2001～2002年相比污染状况有不同程度下降,但其中P素污染比例有上升的趋势;2008～2009年畜禽粪便对耕地、水体造成双重污染的地区为合肥、宿州、蚌埠,这些地区的环境问题应引起注意.     

谈谈水体的生物污染

在人类的生产与生活过程中,可以将各种各样的生物带入水体.其中,有许多种类对人类健康具有一定的危害作用.这种污染,就叫水体生物污染.污染水体的生物种类繁多,但是引起水质恶化,危害人类健康的生物,主要有以下几种:1.细菌:细菌污染水体的主要来源之一,是医院污水.医院污水经常含有大量的病原菌.各种病原菌往往可以通过粪便、垃圾、污水等污染水     

基于现代分子生物学法追溯水体中粪便污染源

研究表明不同生物体粪便中含有已知或未知的病原微生物,所以动物体粪便的排放会携带这些病原微生物到自然水体中,严重污染了水体环境甚至危害人体健康。如何快速、准确鉴定出水体受到的粪便污染来源对进一步研究水体中可能存在的病原微生物至关重要,这也成为目前科学研究的热点。传统的通过监测粪便指示菌的方法指示污染不仅耗时费力,最重要的是它并不能区别出粪便污染的来源。微生物溯源技术(microbial source tracking,MST)的逐渐发展弥补了传统方法的不足,尤其是利用宿主特异性DNA标记物来指示污染源的方法已经取得了突破性进展,并具有高效、快速的特点。该文主要是针对微生物溯源技术的介绍以及如何利用现代分子生物学技术快速追溯水体中粪便污染源的概述。     

浑河（抚顺段）水质粪大肠菌群污染现状研究

近年来，随着城市垃圾、生活污水、工业废水、人畜粪便和医院废水等的不合理排放，导致浑河（抚顺段）水质受到严重污染。粪大肠菌群（Fecal Coliform）是检验水质污染的一个重要生物指标，主要来源于人和混血动物的粪便，对水域进行粪大肠菌群的检测并结合理化分析，可以准确定出水体污染的性质和程度，从而可为水体的污染状况和程度的评估提供科学的依据。本文以粪大肠菌群作为水质粪便污染指标，于2005年监测了浑河（抚顺段）水体粪便污染情况，同时监测了水质COD值。其结果表明，浑河（抚顺段）水体粪便污染严重，粪大肠菌群与COD呈现良好的相关关系。     

甘南州近两年水体粪便污染的研究探索

粪大肠菌群是水体粪便污染的指示菌,是总大肠菌群中的一部分,主要来自于人和温血动物粪便,在44.5℃下能生长并发酵乳糖产酸产气的大肠菌群称为粪大肠菌群。多管发酵法是传统的粪大肠菌群的检测方法。用提高培养温度的方法,造成不利于来自自然环境的大肠菌群生长的条件,使培养出来的菌主要为来自粪便中的大肠菌群,从而更准确地反映出水质受粪便污染的情况。     

养殖系统N、P收支及环境N、P负荷量的研究进展

养殖池塘N、P污染主要来源于残饵、生物排泄、生物粪便和生物残骸分解.污染使养殖池塘、附近河流、湖泊和近海水体富营养化及底质老化问题日益突出.本文根据相关调查和研究资料,阐述了池塘系统N、P的收支、循环、转移和积累变化,以期为控制养殖水体N、P污染和底质“内负荷”污染,提高N、P利用和降低N、P环境负荷量提供理论依据.     

城市地表水中肠道病原微生物与粪便污染指示菌的关系研究

本研究选择肠道病毒、伤寒沙门氏菌、志贺氏菌、大肠埃希氏菌作为城市水体中典型的肠道病原微生物,分别建立起相应的实时荧光定量PCR检测方法.对水源水、景观娱乐用水以及城市河流样品进行长期监测,考察典型肠道病原微生物的分布特征和变化规律.肠道病毒在各地表水体中都有检出,浓度大都在103copy·L-1以下.大肠埃希氏菌的含量在保护良好的水体和接纳城市污水的水体中有明显差别,而伤寒沙门氏菌和志贺氏菌通常出现在受粪便污染较重的水体中.统计学的分析结果显示各种水体中的肠道病原微生物检出浓度均符合对数正态分布规律.粪便污染指示菌与肠道病毒之间不存在显著的相关性,但却能在一定程度上反映典型肠道病原菌的存在情况.在大肠菌群或粪大肠菌群浓度为104CFU·L-1以上的样品中,伤寒沙门氏菌、志贺氏菌具有较高的阳性率.     

苏州市区公厕排污现状与水环境治理

"君到姑苏见,人家尽枕河",唐代诗人的名句把苏州的水乡特征尽展眼前.而现在,苏州的水环境也遭受着工业和生活的双重污染,其中公厕粪便的排污是一个不可忽视的水体污染源.     

快速检测游憩水水质的方法

<正>游泳和冲浪的人因暴露在被人为污染的水体而面临感染胃肠道疾病的风险.目前监测水域粪便污染指示菌所使用的方法,首先需要收集水样,然后在实验室对微生物进行培养和计数,这个过程需要24h.这种延迟可能使游泳者     

顺序氯化消毒工艺的研究

研究了短时游离氯后转氯胺的顺序消毒工艺.结果表明,该消毒工艺对指示微生物的灭活效果优于游离氯消毒,游离氯和氯胺存在协同消毒作用;对脊髓灰质炎病毒和大肠杆菌f₂噬菌体的灭活效果与游离氯相同.相同原水条件下,顺序氯化消毒工艺产生的三卤甲烷浓度比游离氯消毒工艺减少35.8%～77.0%;卤乙酸减少36.6%～54.8%.消毒进水水质越差,顺序氯化消毒工艺在消毒副产物(DBP)控制方面就越具优势.     

Effects of UV intensity and water turbidity on microbial indicator inactivation

The effects of UV intensity and turbidity on selected microbial indicator inactivation were investigated. Results showed that UV disinfection was effective in killing all the selected microbial indicators, the resistance order of the microorganisms was as follows： MS-2 coliphage 〉 Bacillus subtilis 〉 E. coil 〉 Staphylococcus aureus and Candida albicans. UV intensity had influence on the inactivation of all the microorganisms, high UV disinfection efficency was obtained with higher UV intensity. Turbidity had impact on the bacteria inactivation rate, but there was no evidence that turbidity had any negative contribution to MS-2 coliphage. Under the same UV dosage, higher UV intensity could overcome the negative influence of turbidity on UV performance, enhanced microorganism inactivation effect in turbidity water.     

江苏省某市部分农村河道水体和污水处理厂主要工艺环节病毒污染状况调查

为研究江苏省某市农村河道水体和污水处理厂主要工艺环节病毒的污染状况,分析常见理化因素与病毒污染之间的相关性,对江苏省某市部分农村河道水体和污水处理厂主要工艺环节7个水样、1个污泥和2个沉积物样点进行为期9个月的病毒(包括诺如病毒G Ⅰ、诺如病毒G Ⅱ、轮状病毒、札如病毒、腺病毒、星状病毒、肠道病毒)污染状况监测采样(共90份样本),通过阴离子膜吸附-洗脱法进行富集,荧光定量RT-PCR检测法对病毒进行检测,分析病毒污染状况;同时,监测水温、pH、COD(化学耗氧量)、TP(总磷)、TN(总氮)、EC(电导率)和DO(溶解氧)等7个理化指标的变化情况,探讨这些常见理化因素与病毒污染之间的相关性. 结果表明:90份样本中,诺如病毒G Ⅱ检出率为36.67%,肠道病毒检出率为30%,其他病毒检出率均低于诺如病毒G Ⅱ和肠道病毒. 污水处理后出水中有诺如病毒G Ⅱ、肠道病毒和轮状病毒检出,相关性分析显示,水温与诺如病毒G Ⅱ检出率呈显著负相关(P < 0.05). 研究显示,江苏省某市农村河道水体和污水处理厂主要工艺环节存在病毒污染,诺如病毒G Ⅱ为优势毒株;目前的污水消毒处理工艺并不能完全去除病毒,人群在接触外环境水体时,有潜在病毒暴露风险.      

Estimation of Contamination Sources of Human Enteroviruses in a Wastewater Treatment and Reclamation System by PCR–DGGE

A polymerase chain reaction–denaturing gradient gel electrophoresis (PCR–DGGE) method was employed to estimate the contamination sources of human enteroviruses and understand how their dominant strains vary in a wastewater treatment and reclamation system consisting of sewage collection, wastewater treatment with membrane bioreactor and open lakes for reclaimed water storage and reuse. After PCR–DGGE using a selected primer set targeting enteroviruses, phylogenetic analysis of acquired enterovirus gene sequences was performed. Enteroviruses identified from the septic tank were much more diverse than those from grey water and kitchen wastewater. Several unique types of enterovirus different from those in wastewater samples were dominant in a biological wastewater treatment unit. Membrane filtration followed by chlorination was proved effective for physically eliminating enteroviruses; however, secondary contamination likely occurred as the reclaimed water was stored in artificial lakes. Enterovirus 71 (EV71), a hand-foot-and-mouth disease (HFMD) viral pathogen, was detected mainly from the artificial lakes, implying that wastewater effluent was not the contamination source of EV71 and that there were unidentified non-point sources of the contamination with the HFMD viral pathogen in the reclaimed water stored in the artificial lakes. The PCR–DGGE targeting enteroviruses provided robust evidence about viral contamination sources in the wastewater treatment and reclamation system.     

One-year Surveillance of Human Enteric Viruses in Raw and Treated Wastewaters,Downstream River Waters,and Drinking Waters

Human enteric viruses are a major cause of waterborne diseases, and can be transmitted by contaminated water of all kinds, including drinking and recreational water. The objectives of the present study were to assess the occurrence of enteric viruses (enterovirus, norovirus, adenovirus, hepatitis A and E virus) in raw and treated wastewaters, in rivers receiving wastewater discharges, and in drinking waters. Wastewater treatment plants’ (WWTP) pathogen removal efficiencies by adenovirus quantitative real-time PCR and the presence of infectious enterovirus, by cell culture assays, in treated wastewaters and in surface waters were also evaluated. A total of 90 water samples were collected: raw and treated wastewaters (treated effluents and ultrafiltered water reused for industrial purposes), water from two rivers receiving treated discharges, and drinking water. Nested PCR assays were used for the identification of viral DNA/RNA, followed by direct amplicon sequencing. All raw sewage samples (21/21), 61.9 % of treated wastewater samples (13/21), and 25 % of ultrafiltered water samples (3/12) were contaminated with at least one viral family. Multiple virus families and genera were frequently detected. Mean positive PCRs per sample decreased significantly from raw to treated sewage and to ultrafiltered waters. Moreover, quantitative adenovirus data showed a reduction in excess of 99 % in viral genome copies following wastewater treatment. In surface waters, 78.6 % (22/28) of samples tested positive for one or more viruses by molecular methods, but enterovirus-specific infectivity assays did not reveal infectious particles in these samples. All drinking water samples tested negative for all viruses, demonstrating the effectiveness of treatment in removing viral pathogens from drinking water. Integrated strategies to manage water from all sources are crucial to ensure water quality.     

Somatic Coliphage Profiles of Produce and Environmental Samples from Farms in Northern México

Somatic coliphages were quantified in 459 produce and environmental samples from 11 farms in Northern Mexico to compare amounts of somatic coliphages among different types of fresh produce and environmental samples across the production steps on farms. Rinsates from cantaloupe melons, jalapeño peppers, tomatoes, and the hands of workers, soil, and water were collected during 2011–2012 at four successive steps on each farm, from the field before harvest through the packing facility, and assayed by FastPhage MPN Quanti-tray method. Cantaloupe farm samples contained more coliphages than jalapeño or tomato (p range <0.01–0.03). Across production steps, jalapeños had higher coliphage percentages before harvest than during packing (p = 0.03), while tomatoes had higher coliphage concentrations at packing than all preceding production steps (p range <0.01–0.02). These findings support the use of targeted produce-specific interventions at multiple points in the process of growing and packing produce to reduce the risk of enteric virus contamination and improve food safety during fruit and vegetable production.     

Development and Evaluation of a Multiplexed Real-Time TaqMan RT-PCR Assay with a Sample Process Control for Detection of F-specific RNA Coliphage Genogroups I and IV

There are increasing concerns of zoonotic transmission of some animal enteric viruses, such as calicivirus, hepatitis E virus, and rotavirus, which are closely related to human pathogenic strains. Most enteric viruses are detected by molecular techniques because they cannot be cultured. Surrogates such as F-RNA coliphages are cultivable but few molecular methods exist. Individual real-time TaqMan RT-PCR assays for the replicase gene of F-RNA coliphage genogroups I and IV were developed and multiplexed with a real-time TaqMan RT-PCR assay for feline calicivirus as a sample process control for the simultaneous detection and enumeration of genogroup I and IV F-RNA coliphages. Genogroup IV were successfully detected with the multiplexed assay in 80% of fecal samples that contained F-RNA coliphage levels ≥3.2 log plaque forming units (pfu). F-RNA coliphage were at or below the limit of detection in most fecal samples when levels were ≤4 log pfu/g.     

Isolation and Identification of Enteroviruses from Sewage and Sewage-Contaminated Water in Lagos,Nigeria

Studies have confirmed silent circulation of enteroviruses in the environment even in the absence of associated clinical conditions in the community. In this light, 26 samples of sewage and sewage-contaminated water serving selected high-risk communities in Lagos Nigeria were examined between June and September 2010. To concentrate virus particles in the sample, 480 μL of each sample was centrifuged at 3,000 rpm for 1 h at 4 °C. Subsequently, pellets were pooled, chloroform treated and further centrifuged at 1,500 rpm for 20 min at 4 °C. The water phase (concentrate) was then collected and stored at ?20 °C. The concentrates were subsequently inoculated into RD and L20B cell lines. Recovered isolates were identified by real-time RT-PCR (rRT-PCR), serotyping, VP1 amplification, sequencing and phylogenetic analysis. Overall, 9 (34.6 %) of the samples showed characteristic enterovirus cytopathic effect in RD cell line and were subsequently confirmed by pan-enterovirus rRT-PCR. The isolates were further identified by serotyping to include three E7, one E11 and one E13 isolates whilst four isolates were untypable. Further characterisation by VP1 sequencing confirmed the results of serotyping and rRT-PCR for all but isolate E13. Also, the four previously untypable isolates were identified to include two E19, one E20 and one E7 by VP1 sequencing. Results of the study confirmed circulation of Sub-Saharan Africa-specific enterovirus clades in the region, provide information on their molecular epidemiology and emphasise the need to combine methods of identification to enhance enterovirus surveillance.     

逆转录-聚合酶链反应(RT-PCR)技术同时检测水中多种肠道病毒

建立了一种利用通用引物RT-PCR技术检测水中肠道病毒的方法.利用脊髓灰质炎病毒1～3型,柯萨奇病毒B3型作为参考病毒株,根据肠道病毒RNA5′非编码区中具有高度同源性的序列来设计通用引物.比较了M-MLV酶和AMV酶的逆转录效果,AMV酶能够成功地从地表水和生活污水中逆转录病毒RNA,更适于实际应用.对比研究了PCR过程中的退火温度,c(Mg2＋)等因素对RT-PCR检测结果的影响,选择退火温度55　℃,c(Mg2＋)为2　mmol/L的反应条件,优化了RT-PCR检测方法.通过检测水样中接种的连续稀释的病毒,确定了该检测方法的灵敏度为38　CCID₅₀.考察人工污染的地表水、污水、二级处理出水样品发现,检测灵敏度基本一致.该方法可应用在实际环境的肠道病毒检测中.