Bacteriological water assessment of an urban river in Nigeria

The Asa River in Ilorin, Nigeria, which is subject to varied human abuse at its urban fringe areas, was investigated for its pollution status over a period of 2 years. Physical observations including sources of pollution were noted. The degree of faecal pollution was estimated using microbial indicators. Total heterotrophic bacterial counts ranged from 4.5 to 8.5 × 10⁶ ml^‐1 with higher counts occurring during rainy seasons. The total and faecal coliforms ranged from 1.6 X 10⁴ to 1.9 × 10⁷MPN index 100 ml^‐1 were obtained with higher counts being recovered during dry seasons. Between 62 and 92% of the total coliforms were of faecal origin at various locations. It is concluded that for some kilometres the river, especially during the dry season, is simply an offensive and unhealthy drain. The Asa River and its catchment were therefore identified as a high risk environment for humans.     

Studies on well water and possible health risks in Katsina, Nigeria

Well water was sampled from all four major wards in Katsina town. All 20 samples taken showed high coliform counts. Sixty-five per cent contained greater than or equal to 2400 coliforms per 100 ml while the remainder had counts ranging from 79 to 920. Faecal coliforms and non-cholera vibrios were detected in all samples. There was no significant relationship between the coliform counts and the distances of latrines to wells, water table to ground level, slope relationship between wells and latrines, the pH of water and whether the wells were left permanently open or not. Salmonella sp., Enterobacter sp. and Pseudomonas sp. were each isolated from about 10% of the samples, while Proteus sp. was isolated from 40%, Citrobacter sp. 15%, Alcaligenes sp. 5% and an unidentified Gram-negative rod from 5%. Only 2 (10%) of the sampled households, representing 23 (9.6%) of the 239 people exposed to well-water had pipeborne water in addition. It was concluded that well water in Katsina town could be a human health hazard.     

Public health impacts of floods and chemical contamination

INTRODUCTION: Flooding accounts for about 40 per cent of all natural disasters that occur worldwide. In 2002-2003 many counties in England experienced severe floods. Floods are particularly important in public health terms as they may have multiple environmental consequences. METHODS: Details of floods reported to Chemical Hazards and Poisons Division, London [CHaPD(L)] were analysed and a literature review was undertaken to identify published reports of flood-related chemical incidents that have had an impact on public health. RESULTS: Epidemiological evidence shows that chemical material may contaminate homes and that in some cases flooding may lead to mobilization of dangerous chemicals from storage or remobilization of chemicals already in the environment, e.g. pesticides. Hazards may be greater when industrial or agricultural land adjoining residential land is affected. Less evidence exists to support the hypothesis that flooding that causes chemical contamination has a clear causal effect on the pattern of morbidity and mortality following these flooding events. CONCLUSION: In the light of this evidence, a checklist/pro forma for public health response to and investigation of flooding events that may result in chemical contamination was needed. This is available from CHaPD(L).     

Studies on well water and possible health risks in Katsina, Nigeria.

Well water was sampled from all four major wards in Katsina town. All 20 samples taken showed high coliform counts. Sixty-five per cent contained greater than or equal to 2400 coliforms per 100 ml while the remainder had counts ranging from 79 to 920. Faecal coliforms and non-cholera vibrios were detected in all samples. There was no significant relationship between the coliform counts and the distances of latrines to wells, water table to ground level, slope relationship between wells and latrines, the pH of water and whether the wells were left permanently open or not. Salmonella sp., Enterobacter sp. and Pseudomonas sp. were each isolated from about 10% of the samples, while Proteus sp. was isolated from 40%, Citrobacter sp. 15%, Alcaligenes sp. 5% and an unidentified Gram-negative rod from 5%. Only 2 (10%) of the sampled households, representing 23 (9.6%) of the 239 people exposed to well-water had pipeborne water in addition. It was concluded that well water in Katsina town could be a human health hazard.     

综合性医院医护人员工作服细菌污染监测分析

目的了解综合性医院医护人员工作服染菌情况,并提出相应的管理措施。方法连续采集某院2012年5—10月呼吸内科、普通外科、妇科和儿科医务人员穿着清洁工作服后第1、3、7天的样本,共120件,360份标本,对医护人员工作服染菌量进行监测和比较分析。结果穿着不同时间段工作服染菌量比较,差异有统计学意义。工作服穿着时间越长,染菌量越大。护士与医生[(10.65±3.38)CFU/cm2 vs(7.68±2.99)CFU/cm2],手术科室与非手术科室[(10.43±4.12)CFU/cm2 vs(8.60±3.01)CFU/cm2]医务人员穿着工作服平均菌落数比较,差异均有统计学意义(U值分别为5.06、2.78,均P0.01),护士工作服的污染程度高于医生,手术科室高于非手术科室。工作服不同部位污染超标率比较,差异有统计学意义(χ2=33.12,P0.01);其中袖口污染最严重,其次是腹部和胸前,污染超标率分别是73.33%、58.33%、36.67%。结论应加强医务人员工作服清洗制度管理,建议医务人员工作服每周更换2次,污染严重的科室更换频率需加大。     

Faecal contamination of a municipal drinking water distribution system in association with Campylobacter jejuni infections

After heavy rains Campylobacter jejuni together with high counts of Escherichia coli, other coliforms and intestinal enterococci were detected from drinking water of a municipal distribution system in eastern Finland in August 2004. Three patients with a positive C. jejuni finding, who had drunk the contaminated water, were identified and interviewed. The pulsed-field gel electrophoresis (PFGE) genotypes from the patient samples were identical to some of the genotypes isolated from the water of the suspected contamination source. In addition, repetitive DNA element analysis (rep-PCR) revealed identical patterns of E. coli and other coliform isolates along the distribution line. Further on-site technical investigations revealed that one of the two rainwater gutters on the roof of the water storage tower had been in an incorrect position and rainwater had flushed a large amount of faecal material from wild birds into the drinking water. The findings required close co-operation between civil authorities, and application of cultivation and genotyping techniques strongly suggested that the municipal drinking water was the source of the infections. The faecal contamination associated with failures in cleaning and technical management stress the importance of instructions for waterworks personnel to perform maintenance work properly.     

High levels of faecal contamination in drinking groundwater and recreational water due to poor sanitation,in the sub-rural neighbourhoods of Kinshasa,Democratic Republic of the Congo

In many urban and peri-urban areas of developing countries, shallow wells and untreated water from urban rivers are used for domestic purposes, including drinking water supply, population bathing and irrigation for urban agriculture. The evaluation and monitoring of water quality are therefore necessary for preventing potential human risk associated with the exposure to contaminated water. In this study, physicochemical and bacteriological parameters were assessed in an urban river (named Kokolo Canal/Jerusalem River) draining the municipality of Lingwala (City of Kinshasa, Democratic Republic of the Congo) and in two shallow wells used as drinking water supplies, during the wet and dry seasons in order to estimate the seasonal variation of contamination. The faecal indicator bacteria (FIB) isolated strains (Escherichia coli (E. coli) and Enterococcus (ENT)) from water and surface sediment, were characterized for human-specific bacteroides by molecular approach. The results revealed very high faecal contamination of water from the shallow wells, and of water and sediments from the river, during both wet and dry seasons. During the wet season, E. coli reached the values of 18.6?×?10⁵ and 4.9?×?10⁵?CFU 100?mL^?1 in Kokolo Canal and shallow wells, respectively; and Enterococcus reached the values of 7.4?×?10⁴ and 2.7?×?10⁴?CFU 100?mL^?1. Strong mutually positive correlation was observed between E. coli and ENT, with the range of R-value being 0.93?<?r?<?0.97 (p-value?<?0.001, n?=?15). The PCR assays for human-specific Bacteroides indicated that more than 98% of 500 isolated FIB strains were of human origin, pointing out the effect of poor household sanitation practices on surface water but also on groundwater contamination. The water samples from the shallow wells and Kokolo Canal were highly polluted with faecal matter in both seasons. However, the pollution level was significantly higher during the wet season compared to the dry season. Physicochemical analysis revealed also very high water electrical conductivity, with values much higher than the recommended limits of the World Health Organization guideline for drinking water. These results highlight the potential human health risk associated with the exposure to water contamination from shallow wells and Kokolo Canal, due to the very high level of human FIB. Rapid, unplanned and uncontrolled population growth in the city of Kinshasa is increasing considerably the water demand, whereas there is a dramatic lack of appropriate sanitation and wastewater facilities, as well as of faecal sludge (and solid waste) management and treatment. The lack of hygiene and the practice of open defecation is leading to the degradation of water quality, consequently the persistence of waterborne diseases in the neighbourhoods of sub-rural municipalities, and there is a growing threat to the sustainability to water resources and water quality. The results of this study should encourage municipality policy and strategy on increasing the access to safely managed sanitation services; in order to better protect surface water and groundwater sources, and limit the proliferation of epidemics touching regularly the city.     

2009-2012年达州市食源性致病菌监测结果分析

目的监测达州市主要食源性致病菌污染状况,确定本地区高危食品,为预防控制食源性疾病提供科学依据。方法按照国家食源性致病菌监测工作手册要求,多级分层抽样并按标准操作程序进行检测。结果 4年监测10大类食品975件,检出食源性致病菌7种99株,总检出率为10.15%。检出数较多的依次为金黄色葡萄球菌24株、单增李斯特菌20株、蜡样芽孢杆菌18株,检出率较高的依次为副溶血性弧菌25.00%、阪崎肠杆菌21.62%、蜡样芽孢杆菌14.40%。结论达州市食品存在食源性致病菌污染,其中婴幼儿配方食品、冷冻食品和动物性水产品是主要污染食品品种。     

江西省某大型超市自动扶梯扶手表面细菌污染特征分析

目的评估大型超市自动扶梯扶手表面细菌污染现状及影响因素,为提升公共卫生安全提供理论依据。方法于2017年8-10月分层随机抽取某大型超市内6个扶梯,以拭子涂抹法采集细菌并检测菌落总数,以16SrDNA测序技术及聚类分析检测微生物种类,以PCR扩增mecA基因及纸片扩散法(K-B法)检测耐药菌。结果扶梯人流量峰值2 h后,扶手表面菌落总数达到峰值,左、右扶手菌数无明显差异(P>0.05)。176份样品中,有50份样品细菌菌落总数高于10CFU/cm^2(占28.4%),8份样品高于100 CFU/cm^2(占4.5%)。6份样品mecA基因检测呈阳性(占3.4%)。扶手表面检出19株菌,属于4门5纲(芽孢杆菌纲、α-变形菌纲、β-变形菌纲、放线菌纲、散囊菌纲)7属共12种菌株,其中芽孢杆菌纲占50%(6/12),α变形菌纲占25%(3/12),并检出条件性致病微生物蜡样芽孢杆菌和黄曲霉菌。在检出的6株葡萄球菌中,有3株携带mecA基因,并对青霉素、头孢曲松耐药,对氧氟沙星敏感。结论大型超市扶梯扶手表面微生物物种丰富,存在细菌包括耐药葡萄球菌污染,扶手表面污染程度受人流量影响,提示大型超市扶梯扶手存在致病菌传播的潜在风险。     

山东省2003～2007年食源性致病菌监测结果分析

目的为了解山东省食品污染状况,修订食品污染物限量标准,进行食品污染状况评价和预警提供可靠数据。方法采用《全国食品污染物监测相关实验室操作技术手册（细菌部分）》的方法对样品进行沙门氏菌、大肠艾希氏菌0157：H7、单核细胞增生李斯特氏菌、弯曲菌、副溶血弧菌等5种食源性致病菌的检测。结果对生肉、熟肉（散）、蔬菜、水产品等食品的病菌进行检测,检测样品1833份,分离菌株共268株,包括：沙门氏菌38株、单增李斯特氏菌133株、出血大肠01570株、弯曲菌18株、副溶血弧荫79株,总阳性菌株268株,占总检测数的14．6％。讨论食源性致病菌污染相对较高,肉及肉制品尤为严重,建议在食品加工制作各个环节减少污染,避免食源性疾病发生。食源性致病菌的主动监测是一项连续性的工作,应加强主动监测,保证食品安全。     

Faecal steroid excretion in humans is affected by calcium supplementation and shows gender-specific differences

Background  Previous human studies on the effect of dietary calcium supplementation on faecal excretion of bile acids (BA) and faecal water concentrations of animal neutral sterols (NSt, cholesterol and its metabolites) lack detailed information about single BA and NSt. Aim of the study  We investigated whether single BA and NSt in faeces and especially in faecal water are affected by calcium supplementation and whether this affects genotoxicity of faecal water. In addition, we differentiated between men and women with regard to the concentrations of BA and NSt in faecal water. Methods  Thirty-one healthy volunteers consumed a calcium supplemented bread (1.0 g/day) and a placebo bread, respectively, for 4 weeks in a double-blind, randomised cross-over trial. Faeces were collected quantitatively for 5 days in the last week of each period. NSt and BA were analysed by GC–MS. Results  Due to calcium supplementation faecal concentrations of lithocholic acid (LCA, 14%, P = 0.008), deoxycholic acid (DCA, 19%, P < 0.001) and 12keto-deoxycholic acid (12keto DCA, 29%, P = 0.049) significantly increased whereas BA concentrations in faecal water were only marginally affected. In contrast, concentrations of cholesterol (30%, P = 0.020) and its metabolites coprostanol (43%, P = 0.004), coprostanone (36%, P = 0.003), cholestanol (44%, P = 0.001) and cholestenone (32%, P = 0.038) in faecal water significantly decreased. Total NSt concentration in faecal water was found to be significantly higher in women compared to men (P = 0.018). The genotoxicity of faecal water was neither affected by calcium supplementation nor were there gender-specific differences. Conclusions  Dietary calcium supplementation diversely affects BA and NSt in faeces and in faecal water but does not influence the genotoxicity of faecal water in healthy adults.     

Natural and technical factors in faecal contamination incidents of drinking water in small distribution networks, France, 2003-2004: a geographical study

This geographical study aimed to show natural or water-processing-related factors of faecal contamination incidents (FCIs) of drinking water in continental France. We defined a FCI as the occurrence of at least 20 colony-forming Escherichia coli or enterococci among all the 100 mL samples collected for regulatory purpose within one day from a given drinking water supply zone (SZ). We explored correlations between the standardized number of FCIs per département (N_Pols) and various indicators related to weather, land cover, topography, geology and water management for three SZ size sub-classes. In 2003–2004, 2,739 FCIs occurred in SZs supplying fewer than 2,000 people, mainly with simply disinfected groundwater. N_Pols correlates with four covariates: (1) precipitation; (2) the extension of the karst outcrops; (3) the extent of disinfection; and (4) catchment protection. One hundred millimetres of yearly excess in precipitation increases the pollution risk by 28–37%, depending on the sub-class. A 10% extension of the karst areas, a 10% increase of unprotected resources, or of SZs with no disinfection, could entail a higher risk of FCI by about 10%. The correlations are reproducible over the three sub-classes and corroborate expert appraisals. These results encourage the ongoing effort to generalize disinfection and catchment protection.     

Bacterial contamination of preserved and non-preserved metal working fluids

Metal working fluids (MWFs) are important facilities for certain industrial processes. Besides their advantage concerning the effective technical applicability it is disadvantageous that they are excellent culture media for bacterial and fungal growth and may therefore act as an infectious source for employees getting in contact with them. As a matter of prevention most of MWFs are nowadays treated with preservatives to eliminate the contamination of possible human pathogenic bacteria and fungi.

Own investigations were concerned with the objectives of

the actual and long-term study of the bacterial contamination of preserved and non-preserved MWFs from different MWF systems,

the development of a standardized bacterial biotope in non-preserved MWFs and its efficacy to eliminate bacteria which caused infectious diseases in humans,

the development of bacterial resistance against preservatives in preserved MWFs and

the occurrence of infections and allergies in employees working with MWFs.

Our results show:

high numbers of different bacteria can be found in non-preserved as well as preserved MWFs,

bacteria with a possible human pathogenic potential (category 2, TRBA 466) could almost exclusively be found in preserved MWFs. Those bacteria besides others were able to develop resistance against biocides and could therefore be detected in preserved MWFs for weeks and months,

non-preserved MWFs develop stable bacterial biotopes which can be controlled by an artificial inoculation of bacteria. Those biotopes are able to eliminate bacteria which induce infectious diseases in humans,

there are only very few data published concerning MWF caused infections or allergies. According to our results of a questionnaire 10% of employees getting in contact with MWFs, complain skin irritations/reactions. There was no difference working with preserved or non-preserved MWFs nor a clear cut correlation to the MWF contact. These data may motivate for more intensive epidemiological studies in this field.

The results of our investigations point out that taking into consideration safe working conditions non-preserved MWFs even contaminated with a standardized combination of waterborne bacteria like Pseudomonas spec. up to 10⁸ CFU/ml are an alternative to preserved MFWs.     

健康产业作为长三角区域战略性新兴产业的研究

健康产业是极具发展潜力的新兴产业。长三角地区作为我国经济率先发展的地区,大力发展健康产业正当其时,不仅有助于改造提升长三角地区的传统工业、促进地区战略新兴产业的发展、推进地区经济发展方式转变,也是促进长三角地区经济增长与保障民生有机结合的重要措施。     

Microbial contamination in vegetables due to irrigation with partially treated municipal wastewater in a tropical city

A total of 144 samples of water used for irrigation were collected from Dinapur, DLW sewage treatment plant and river water of Ganga at Rajghat and 258 irrigated vegetable samples were collected from nearby agricultural fields in the close vicinity of three treatment plants and examined using standard procedures for coliform and viable counts and the presence of Escherichia coli, Salmonella, Clostridium and Vibrio during the winter and rainy seasons. Irrigation water from Rajghat drain had significantly higher coliform counts by location and season than the water from the Dinapur and DLW. Although all the vegetables had coliform counts higher than the recommended standard (range 3.40 - 6.38 log10 cfuml(-1)), spinach and cabbage had significantly higher (p < 0.05) counts compared to other vegetables during the dry season. Salmonella was significantly more likely to be detected during the rainy season than during the dry season. Contaminated vegetable intake may pose a serious threat to human health.     

Health significance of Gram‐negative bacteria associated with waste‐fed tropical aquaculture system

Commercially important freshwater fish species, Cyprinus carpio, Oreochromia niloticus, Sarother‐odon galilaeus and Clarias anguillaris grown in aquaculture ponds receiving untreated sewage and animal faecal waste and in an untreated concrete tank were sampled to determine the presence of potentially pathogenic Gram negative bacteria to man. The resistance of some representative bacterial isolates to some commonly used antibacterial drugs were also determined. Fourteen bacterial species from nine genera, namely, Escherichia, Citrobacter, Enterobacter, Proteus, Salmonella, Serratia, Klebsiella, Pseudomonas and Aeromonas from both fish intestinal tracts and culture water samples were identified. Escherichia coli predominated in the sewage and animal manure‐treated ponds, while fluorescent Pseudomonas were common in the untreated pond. Pathogenic Salmonella spp. were isolated at a low frequency (1.32%) in fish from the sewage pond. Of the 577 bacterial isolates identified, 199 (34.49%) were resistant to at least one antibacterial drug.     

Faecal contamination of drinking water in a Brazilian shanty town: importance of household storage and new human faecal marker testing

Worldwide, contaminated drinking water poses a major health threat, particularly to child development. Diarrhoea represents a large part of the water-related disease burden and enteric infections have been linked to nutritional and growth shortfalls as well as long-term physical and cognitive impairment in children. Previous studies detailed the frequency of infection and the consequences for child health in a shanty town in north-east Brazil. To determine the frequency of contaminated water, we measured faecal contamination in primary drinking water samples from 231 randomly selected households. Risk for contamination was compared across source and storage types. Nearly a third of the study households (70/231: 30.3%) had contaminated drinking water; the source with the highest frequency of contamination was well water (23/24: 95.8%). For tap water, the type of storage had a significant effect on the susceptibility to contamination (c²=12.090; p=0.007). The observed pattern of contamination demonstrated the relative potential contributions of both source and storage. With evidence that supports the inclusion of source and storage in water quality surveys, this study, like others, suggests that contaminated drinking water in storage vessels may be an important factor for the documented diarrhoea disease burden in the Brazilian shanty town.