Comparison of the bacteriological quality of tap water and bottled mineral water

The bacteriological quality of tap water from municipal water supplies, 20-L bottles of mineral water from water dispensers and samples collected from new 20-L bottles of mineral water were comparatively studied. Total coliforms, termotolerant coliforms, Escherichia coli, fecal streptococci, Pseudomonas aeruginosa, Staphylococcus spp. and heterotrophic plate count were enumerated. The results showed that 36.4% of the tap water samples from municipal water systems and 76.6% of the 20-L bottles of mineral water from water dispensers were contaminated by at least one coliform or indicator bacterium and/or at least one pathogenic bacterium. The bacteriological quality of municipal tap water is superior when compared with the 20-L bottles of mineral water collected from water dispensers and samples collected from new 20-L bottles of mineral water before installation in the dispensers. This highlights the need for an improved surveillance system for the bottled water industry. For the municipal water systems, it is recommended to perform the Pseudomonas enumeration periodically, in addition to the routine data collected by most systems.     

Bacteria and disinfection byproducts in water from southern Mexico City

Disinfection byproducts and microorganisms present in drinking water may have deleterious effects on human health. The authors examined bacterial indicators (enterobacteria and Helicobacter pylori [H. pylori]), physicochemical parameters, and trihalomethane (THM) levels to conduct a water quality evaluation in Mexico City, where little is known about disinfection byproducts and microbial counts. Analyses were performed by standard membrane filtration for the enumeration of total coliforms, fecal coliforms, fecal streptococci, and Vibrio species. Other testing consisted of polymerase chain reaction (PCR) for H. pylori, physicochemical parameters by selective electrodes, and THMs by head-space with the use of a gas chromatograph. Indicator bacteria and enterobacteria were detected in 23% of samples, with significant differences between total coliforms, fecal coliforms, and fecal streptococci before and after chlorination. H. pylori was detected in 69% of samples prior to chlorination and 57% postchlorination. THM levels were < 200 microg/l. Chlorine concentrations ranged from < 0.05 mg/l to 35 mg/l. Disinfection at the well does not ensure good water quality for the Mexico City population. The next step will be the monitoring of water quality in the distribution system that supplies dwellings, as well as water obtained directly from the tap.     

A follow-up study of gastro-intestinal diseases related to bacteriologically substandard drinking water

In a prospective follow-up study conducted in 52 French alpine villages, one weekly water sample was taken in each village provided with untreated ground water and analyzed as to the presence of four indicator bacteria: total plate count, total coliforms, thermotolerant (fecal) coliforms, and fecal streptococci. Cases of acute gastro-intestinal disease (AGID) occurring among 29,272 inhabitants were reported through physicians, pharmacists, and primary school teachers. A loglinear model identified fecal streptococcus (FS) as the best predictor; the presence of fecal coliforms enhanced the effect of FS. The total bacteria count and the total coliforms had no independent contributions. A threshold analysis suggested that any level of indicator bacteria above zero was associated with an excess of AGID.     

Physicochemical and bacteriological assessment of water quality at the Ross Barnett reservoir in central Mississippi.

The Ross Barnett Reservoir serves as a source of water supply for the city of Jackson, Mississippi, U.S.A. and is an important site for recreational activities for many residents of Mississippi counties. A broad spectrum of illness is associated with water-contact activities like bathing and swimming in recreational waters. In the present research, we assessed the bacteriological quality of water in the Ross Barnett Reservoir and compared the levels of bacteria with the recommended criteria for public health protection. From June 12, 1999 to October 2, 1999, we collected water samples weekly from two different sites in the reservoir and tested them for the following bacteriological parameters: heterotrophic plate counts, total coliforms, fecal coliforms, and fecal streptococci. The samples were also tested for basic physical and chemical characteristics of water. The results of the study indicate that the respective mean concentrations of bacteria (colony forming units per 100 mL of water) in water samples collected from the reservoir were 5.6 x 10(6)+/-1.5 x 10(6) (heterotrophic plate counts), 4.5 x 10(4) +/- 5.3 x 10(4) (total coliforms), 5.0 x 10(2) +/- 1.6 x 10(2) (fecal coliforms), and 9.1x10(1)+/-7.3x10(1) (fecal streptococci). The values of all physical and chemical parameters were at acceptable levels. The bacterial densities, however, often exceeded federal/state guidelines by several orders of magnitude, raising considerable public health concerns. Steps should therefore be taken to develop and implement strategies to improve the water quality and to reduce or eliminate the potential health risks associated with water-contact activities in the Ross Barnett Reservoir.     

Recreational water quality control in Mississippi, USA: bacteriological assessment in the Pearl River and Ross Barnett reservoir

We assessed the bacteriological water quality in the Pearl River and Ross Barnett reservoir, a major source of public raw water for the city of Jackson, Mississippi, USA and an important site for recreational activities for local residents and visitors. Infectious diseases caused by pathogenic bacteria are the most common and widespread health risks associated with such water contact activities as bathing, canoeing, and swimming in recreational waters. Water samples collected twice monthly from April 2004 to April 2005 from five different sites of the Pearl river/Ross Barnett reservoir were tested for heterotrophic bacteria, total coliforms, fecal coliforms, and enterococci using membrane filtration technique. Physicochemical parameters (temperature, pH, turbidity, dissolved oxygen, conductivity) were also analyzed using standard methods. The respective mean concentrations of bacteria in water samples were 8.9 x 10(4) +/- 7.4 x 10(4) colony forming units (CFU) 100 mL(-1), 3.0 x 10(3) +/- 4.1 x 10(3) CFU 100 mL(-1), 2.3 x 10(2) +/- 5.4 x 10(2) CFU 100 mL(-1), and 2.3 x 10(2) +/- 4.8 x 10(2) CFU 100 mL(-1) for heterotrophic bacteria, total coliforms, enterococci, and fecal coliforms. The mean values of the physical and chemical parameters were at acceptable levels. Bacterial densities, however, significantly exceeded federal/state guidelines, raising public health concerns. Hence, control strategies should be developed and implemented to prevent further bacterial contamination of Pearl River-Ross Barnett reservoir water resource system.     

Microbiological quality of drinking water of urban and rural communities,Brazil

OBJECTIVE: To evaluate the microbiological quality of treated and untreated water samples came from urban and rural communities and to examine the relationship between coliforms occurrence and average water temperature, and a comparison of the rainfall levels. METHODS: A sample of 3,073 untreated and treated (chlorinated) water from taps (1,594), reservoir used to store treated water (1,033), spring water (96) and private well (350) collected for routine testing between 1996 and 1999 was analyzed by the multiple dilution tube methods used to detect the most probable number of total and fecal coliforms. These samples were obtained in the region of Maring , state of Paran , Brazil. RESULTS: The highest numbers water samples contaminated by TC (83%) and FC (48%) were found in the untreated water. TC and FC in samples taken from reservoirs used to store treated water was higher than that from taps midway along distribution lines. Among the treated water samples examined, coliform bacteria were found in 171 of the 1,033 sampling reservoirs. CONCLUSIONS: Insufficient treatment or regrowth is suggested by the observation that more than 17% of these treated potable water contained coliform. TC and FC positive samples appear to be similar and seasonally influenced in treated water. Two different periods must be considered for the occurrence of both TC and FC positive samples: (i) a warm-weather period (September-March) with high percentage of contaminated samples; and (ii) cold-weather period (April-August) were they are lower. Both TC and TF positive samples declined with the decreased of water temperature.     

Microbial quality of water in rural communities of Trinidad.

A cross-sectional study was conducted in four rural communities of northeastern Trinidad to determine the microbial quality of water supply to households and that quality's relationship to source and storage device. Of the 167 household water samples tested, total coliforms were detected in 132 of the samples (79.0%), fecal coliforms in 102 (61.1%), and E. coli in 111 (66.5%). There were significant differences among the towns in the proportion of the samples contaminated with coliforms (P < 0.001) and E. coli (P < 0.001). Of 253 strains of E. coli studied, 4 (1.6%) were mucoid, 9 (3.6%) were hemolytic, and 37 (14.6%) were nonsorbitol fermenters. Of 69 isolates of E. coli tested, 10 (14.5%) were verocytotoxigenic. Twenty-eight (14.0%) of 200 E. coli isolates tested belonged to enteropathogenic serogroups. Standpipe, the most common water source, was utilized by 57 (34.1%) of the 167 households. Treated water (pipeborne in homes, standpipes, or truckborne) was supplied to 119 households (71.3%), while 48 households (28.7%) used water from untreated sources (rain, river/stream, or well) as their primary water supply. The type of household storage device was associated with coliform contamination. Water stored in drums, barrels, or buckets was more likely to harbor fecal coliforms (74.2% of samples) than was water stored in tanks (53.3% of samples), even after controlling for water source (P = 0.04). Compared with water from other sources, water piped into homes was significantly less likely to be contaminated with total coliforms (56.9% versus 88.8%, P < 0.001) and fecal coliforms (41.2% versus 69.8%, P < 0.01), even when the type of storage device was taken into account. However, fecal contamination was not associated with whether the water came from a treated or untreated source. We concluded that the drinking water in rural communities in Trinidad was grossly unfit for human consumption, due both to contamination of various water sources and during household water storage.     

福清市居民饮用水现状调查

目的掌握福清市居民饮用水现状,为政府决策提供科学依据。方法对福清市102家小型集中式供水和569户分散式饮水抽样调查分析。结果该市居民集中式供水占46.75%,分散式供水占53.25%;集中式供水主要以水库为水源占53.84%,分散式供水主要以浅井为主占85.00%;小型集中式供水水质未处理的占总水厂数90.00%;小型集中式供水水质合格率为47.79%,其中细菌总数、总大肠菌群、耐热大肠菌群的合格率分别为79.17%、56.86%、71.08%;分散式供水水质合格率24.08%,其中细菌总数、总大肠菌群、耐热大肠菌群的合格率分别为76.45%、43.59%、56.41%。结论福清市约50%居民为分散式供水,改水任务任重道远;饮用水水质合格率低,微生物超标为主因。     

Salmonellas and fecal coliforms in drinking water for animals]

Sixty small farms of Botucatu County, S. Paulo, Brazil, given over to cattle breeding were studied. These farms account for 15% of the total of 402 farms that exist in the county. The sample was drawn by simple probabilistic technique. There were found to be one hundred and thirteen drinking places located on the farms. Samples of water were taken from these drinking places and examined for bacteria of the genus Salmonella, for the determination of Most Probable Number (MNP) of fecal coliform bacteria as well as determination of the water's pH. Water temperature was measured before collection. Samples from 15 drinking places (13.3%) were positive for Salmonella. The drinking places belonged to 12 of the sixty farms studied (20%). The following serotypes were identified: S. dublin, S. newport, S. madelia, S. IV 43:g,z57:-, S. saphra, S. glostrup, S. IV ochsenzool; S. I9,12:i:- and two new serotypes S. IV 41:z52:- and S. IV 50:d:-. Of the 113 samples studied 14 (12.4%) presented MPN/100ml of fecal coliforms above 4,000. There was no relationship between MPN/100ml of fecal coliforms above 4,000 and positivity for Salmonella. Highest positivity both for Salmonella and MPN/100mL of fecal coliforms over 4,000 occurred at temperatures above 18 degrees C. As regards pH, in both situations the highest positivity occurred between 6.0 and 7.0.     

A survey of the microbiological quality of private water supplies in England

Results from statutory testing of private water supplies in nine Public Health Laboratories in England were compiled, and the effects of supply class, source, treatment and location on water quality were examined. A total of 6551 samples from 2911 supplies was examined, over a 2-year period, of which 1342 (21%) samples, and 949 (33%) supplies on at least one occasion, failed current regulations for Escherichia coli. Total coliforms, including E. coli, were detected in 1751 (27%) samples from 1215 (42%) supplies. The percentage of samples positive for E. coli was highest in summer and autumn, and lowest in winter. Samples taken from larger supplies and from boreholes were less frequently contaminated than those from other sources. Chlorination, filtration or UV light treatment improved the bacteriological quality of supplies, but still resulted in a low level of compliance with the regulations. The public health implications of the study are discussed.     

Bacterial water quality in the personal water bottles of elementary students

BACKGROUND: Samples of drinking water were collected directly from the personal water bottles of students at an elementary school in Calgary, Alberta. METHODS: Total and fecal coliforms and heterotrophic bacteria were enumerated using membrane filtration and agar plate count methods respectively. RESULTS: The Canadian Drinking Water Quality Guidelines (CWQG) criterion was exceeded for total coliform in 13.3% of 75 samples. Fecal coliform and total heterotrophic criteria were exceeded in 8.9% (of 68 samples) and 64.4% (of 76 samples) respectively. FINDINGS: The use of personal water bottles for students in elementary classrooms is not recommended.     

Hygiene of bathing waters

Bathing is possible without any epidemic risk in Southbavarian lakes. Limit values according to the water monitoring by the EC-Directive 76/160/EC were rarely exceeded and occurred only in 0.3 to 2.1 % of the samples from 1990 to 1998. In river waters, however, limit values occurred in 17 to 35.3 % of the samples and one should beware of bathing there. In 1999 some lakes became fecally polluted by overflows which could be documented by high numbers of total coliforms but not by Escherichia coli. Subsequently total coliforms functioned as an important hygienic parameter. Therefore, total coliforms should not be abolished in the revision of the EC-Directive. Water monitoring of little lakes further revealed that the future limit value of 100 fecal streptococci in 100 ml was exceeded in more than 50 % of the samples. Enterohaemorrhagic E. coli were demonstrated in 2 % of the surface water samples. Thermophilic campylobacters could be isolated from 17.4 % of bathing water samples which were faultless according to the hygienic parameters of the EC-Directive. In this respect all possibilities should be utilized to minimize fecal pollutions at bathing places.     

A prospective study of swimming-related illness. II. Morbidity and the microbiological quality of water

A prospective cohort epidemiological-microbiological study was carried out at 10 beaches in Ontario, Canada. Lake water and sediment samples collected at the beaches were analyzed for fecal coliforms, fecal streptococci, heterotrophic bacteria, Pseudomonas aeruginosa, and total staphylococci. Mean fecal coliform levels in the surface water of the lakes were within accepted guidelines. Bacterial densities were found to be approximately 10 times higher in the sediment than in the corresponding surface water samples. Morbidity among swimmers was shown to be related to staphylococcal counts, to fecal coliform levels, and, somewhat less strongly, to fecal streptococcal counts. Total staphylococci appeared to be more consistent indicators for predicting total morbidity rates among swimmers.     

Nitrate, coliforms, and Cryptosporidium spp. as indicators of stream water quality in western Pennsylvania

Surface-water treatment plants provide water to approximately 67 percent of the residents of Pennsylvania. Industrial activities and agricultural practices significantly contribute to the chemical and microbiological load of surface-water systems. For the study reported here, surface water from three sites along Two Lick Creek in Indiana County in Pennsylvania were sampled and analyzed for nitrate, iron, total and fecal coliforms, and Cryptosporidium oocysts. Mean nitrate concentrations were 2.88, 3.15, and 3.83 mg/L for Site 1, Site 2, and Site 3, respectively, while mean total-coliform counts ranged from 6.89 x 10(2) to 22.40 x 10(2) CFUs per 100 mL, and fecal coliform counts ranged from 0.30 x 10(2) to 11.1 x 10(2) CFUs per 100 mL. Cryptosporidium oocysts ranged from a low of <46 to a high of 91 per 100 L depending on sample turbidity. The recovery rates of oocysts from spiked samples ranged from 22 percent (low-turbidity samples) to a low of 0.76 percent (high-turbidity samples). This paper discusses the impact of environmental factors on nitrate concentration, coliforms, and Cryptosporidium, as well as the health significance of these water quality indicators.     

一种改良的化妆品微生物检测方法的探讨

目的:用改良法检测化妆品中的微生物,将检测结果与《化妆品卫生规范》(2007年版)方法进行比较。方法:分别用《化妆品卫生规范》(2007年版)方法和改良方法对1000件样品进行菌落总数、霉菌和酵母菌、粪大肠菌群、铜绿假单胞菌和金黄色葡萄球菌的检测。改良方法为:用SCDLP增菌液代替生理盐水稀释样品,进行菌落总数、霉菌和酵母菌检测;SCDLP增菌后,用卵磷脂吐温80营养琼脂培养,对粪大肠菌群、铜绿假单胞菌和金黄色葡萄球菌筛选检测,并结合生化酶反应进行鉴定。结果:1000件样品的检测结果为:3件样品菌落总数指标超标;4件样品菌落总数和霉菌和酵母菌两项指标超标;1件样品菌落总数、霉菌和酵母菌、粪大肠菌群、铜绿假单胞菌和金黄色葡萄球菌五项指标均超标,共8件不合格样品,样品合格率为99.2%。两种方法检测结果相同。结论:改良法操作简便快捷,适合化妆品日常微生物的快速检测。     

Coliforms in the water supply of fast-food chains in the Metropolitan Region of Recife, in the state of Pernambuco (Brazil)

A guaranteed supply of clean drinking water in food outlets is a relevant subject for public health. The scope of this study was to assess the microbiological quality of 96 water samples of a network of fast-food stores in the city of Recife (state of Pernambuco, Brazil) and Metropolitan Area and to compare the results to the standards established by Brazilian Health Ministry decree no 518/2004. Every month, a double sample from one of the faucets in the food preparation area of the eight stores investigated was analyzed, totaling 96 samples over one year. The analyses followed the established methodology of American Public Health Association (APHA), in order to conduct the Presence-Absence Test, considering the potability standard in pertinent legislation. Results revealed that 11.46% and 1.04% of samples contained water contaminated with total coliforms and thermotolerant coliforms, respectively. The quality of the water in the food establishments studied is thus a health hazard since a significant percentage of samples analyzed were inappropriate for human consumption in accordance with current legislation, which stipulates the absence of total coliforms and thermotolerant coliforms.     

随州市农村居民集中供水饮用卫生质量分析

目的:了解随州市农村居民生活饮用水水质卫生状况,为随州地区农村安全饮水工程建设和管理提供科学依据,保护人民群众身体健康。方法:对随州市辖区内66处农村居民生活饮用水集中供水水厂出厂水、管网未稍水进行抽样调查,按《生活饮用水卫生标准检验方法》(GB5750-2006)、《生活饮用水卫生标准》(GB5749-2006)进行检测评价。结果:本次调查的随州市辖区内农村居民集中供水饮用水水质合格率仅为15.5%,不合格项目主要有总大肠菌群、细菌总数、耐热粪大肠菌群、感官指标、耗氧量、铁、锰。结论:随州市辖区内农村居民集中式供水水质合格率低,应加强卫生质量监测,完善净化消毒工艺,解决农村居民饮用水安全隐患。     

Microbiological quality of carbonated drinking water produced with in-home carbonation systems

The microbiological quality of carbonated water produced with tap water in commercial in-home carbonation systems was determined, the results being discussed in the context of the microbiological quality of the tap water used, the properties of the drink makers, and the procedures of preparation and washing of various parts of the appliance. The last-mentioned data were received from each participant of the study by questionnaire. Escherichia coli, coliforms, fecal streptococci and spore-forming sulphite-reducing anaerobes were used as indicators for the hygienic quality of the water. Tap-water samples were collected according to the usual procedure when filling the carbonating bottle, i.e., without previous flushing and disinfection of the faucet. In 12% of tap-water samples, coliforms could be detected. On the other hand, in 20 of 52 carbonated waters (39%), coliforms as indicators of water pollution were found. By means of fecal streptococci and Pseudomonas aeruginosa, it was possible to establish additional contamination not involving E. coli or coliforms alone. Analysis revealed that, in addition to contaminated tap water, a bacterial biofilm on the inner surface of the re-usable bottles had a predominant influence on the microbiological quality of the carbonated water.     

Drinking water microbiological survey of the Northwestern State of Sinaloa, Mexico

A potable water survey, in two important municipalities of the state of Sinaloa, Mexico was conducted. Culiacan, capital city of Sinaloa and its neighboring municipality, Navolato were selected to enumerate Aeromonas hydrophila, Escherichia coli, fecal and total coliforms, Pseudomonas aeruginosa, and Heterotrophic plate count bacteria from 100 households' taps. Manganese; residual chlorine; pH; temperature and turbidity were also examined. Overall, Aeromonas hydrophila was not detected in any of the samples, 3% contained Escherichia coli, 28% had fecal and 46 total coliforms, P. aeruginosa was present in 15% of the samples. HPC bacteria were found in all of the samples but 43% had numbers greater than 500 CFU per ml. The average numbers obtained for the physico-chemical parameters were 0.15 mg/L; 0.32 mg/L; 6.5; 28.7 degrees C and 2.92 NTU for manganese, residual chlorine, pH, temperature and turbidity, respectively. The findings of the current study demonstrate that potable water from both municipalities can harbor substantial numbers of indicator and opportunistic pathogens suggesting that additional treatment in the household may be needed.     

Longitudinal study of the risks related to the consumption of water not conforming to bacteriological norms

A prospective follow-up study lasting 18 months in 1983-1984 was conducted in 50 villages in order to assess the risk related to the consumption of drinking water which did not meet the bacteriology standards. 119 physicians, 52 pharmacists and 118 primary-school teachers enumerated the cases of acute gastro-intestinal diseases observed among a population of 29,272 inhabitants. A weekly water sample was analysed in each village as to the presence of four indicator germs of fecal contamination: total plate count, total coliforms, fecal coliforms (thermotolerant) and fecal streptococci. 1,950 cases of acute gastro-intestinal diseases were registered by the physicians and pharmacists during a population experience of 1,873,303 persons-weeks, i.e. an incidence density of 1.06 X 10(-3) cases per person-week. The risk notified by the school teachers among children aged 7 to 11 was higher: 16.3 X 10(-3) cases per child-week. The villages were classified in 3 groups, according to the proportion of substandard samples: "good", "intermediate", and "bad" categories. The relative risk contrasting the "bad" and "good" villages was 3.5 for the cases notified by the physicians and the pharmacists among the general population (95% confidence interval = 2.5-4.8); it was 1.7 for the cases reported by the teachers among the children (95% confidence interval = 1.5-1.9). This concordant difference was very significant but not constant across the 18 months of the survey. The authors conclude that the bacteriology standards are a relevant indicator of a health hazard.