Bacterial Load Consistency Among Three Independent Water Distribution Systems

Journal of Food Protection, 2006

Three water dispensers (coolers) were bacteriologically monitored over a period of 3 months to evaluate their hygienic status. For this purpose, 174 samples of chilled and unchilled water were analyzed for levels of mesophilic aerobic bacteria and the presence of Escherichia coli and enterococci in 100-ml samples, and the presence of Pseudomonas aeruginosa in 10-and 100-ml samples. Additionally, 12 samples from 20-liter plastic bottles of spring water used to supply the coolers and 36 samples of 12 different brands of noncarbonated bottled mineral water were similarly analyzed. Water from the coolers yielded aerobic plate counts of 3 to 5 log CFU/ml with a geometric mean of 3.86 log CFU/ml, whereas water from the 20-liter bottles had a mean aerobic plate count of 3.3 log CFU/ml. Aerobic plate counts for noncarbonated mineral waters were generally lower (13 samples, <10 CFU/ml; 6 samples, 10 to 102 CFU/ml; 13 samples, 102 to 103 CFU/ml; 3 samples, 103 to 104 CFU/ml; 1 sample, 2 × ...

Journal of Food Agriculture and Environment

Three water dispensers (coolers) were bacteriologically monitored over a period of 3 months to evaluate their hygienic status. For this purpose, 174 samples of chilled and unchilled water were analyzed for levels of mesophilic aerobic bacteria and the presence of Escherichia coli and enterococci in 100-ml samples, and the presence of Pseudomonas aeruginosa in 10and 100-ml samples. Additionally, 12 samples from 20-liter plastic bottles of spring water used to supply the coolers and 36 samples of 12 different brands of noncarbonated bottled mineral water were similarly analyzed. Water from the coolers yielded aerobic plate counts of 3 to 5 log CFU/ml with a geometric mean of 3.86 log CFU/ml, whereas water from the 20-liter bottles had a mean aerobic plate count of 3.3 log CFU/ml. Aerobic plate counts for noncarbonated mineral waters were generally lower (13 samples, Ͻ10 CFU/ml; 6 samples, 10 to 10 2 CFU/ml; 13 samples, 10 2 to 10 3 CFU/ml; 3 samples, 10 3 to 10 4 CFU/ ml; 1 sample, 2 ϫ 10 4 CFU/ml). Although occasional professional cleaning of the coolers did not affect the aerobic plate count, P. aeruginosa was successfully eliminated 2 weeks after cleaning, with only one cooler becoming recolonized. Neither E. coli nor enterococci was found in any of the water samples tested. However, P. aeruginosa was identified in three (25%) of twelve 100-ml samples from 20-liter bottles of spring water; a similar frequency of 24.1% was seen for water samples from coolers. Overall, 35 (21.6%) of 162 water samples (10 ml) from coolers also yielded P. aeruginosa, suggesting potential growth of P. aeruginosa in the dispensers. Pulsed-field gel electrophoresis typing and antibiotic susceptibility testing found 19 P. aeruginosa isolates from the coolers and bottles to be identical, indicating that a single strain originated from the bottled water rather than the surroundings of the coolers. Because P. aeruginosa can cause serious nosocomial infections, its spread should be strictly controlled in institutions caring for vulnerable people such as hospitals and nursing homes. Consequently, in keeping with legal requirement for bottled spring and mineral water in Switzerland, it is also advisable that P. aeruginosa be absent in 100-ml samples of cooler water.

BMC Microbiology, 2010

Background: Water coolers are popular in office buildings and commercial stores and the quality of this source of drinking water has the potential to cause waterborne outbreaks, especially in sensitive and immunocompromised subjects. The aim of this study was to determine the quality of water plumbed in coolers from commercial stores in comparison with tap water in Italy.

Journal of Human Environment and Health Promotion, 2017

"Background: Safe drinking water is one of the main factors in improving health status of the population. The aim of this study was assessment of the microbiological quality, determination of pH and residual chlorine in water coolers’ drinking water in educational centers of Zanjan University of medical Sciences in 2015 and comparing the results with the Iranian national standards. Methods: In this cross-sectional study, water samples of all used water cooler apparatuses were sampled and transferred rapidly to the laboratory. pH and residual free chlorine were measured by pH meter and Chlorine Residual Testing kit, respectively. Total coliforms, Escherichia coli, Mold and yeasts count were enumerated according to the Iranian national standards No. 1011, 3759, 5271 and 10899-1, respectively. Data were analyzed through the statistical softwares. Results:The obtained results indicated that 44.44% of the samples were non-standard because of low residual chlorine. 44.44% and 27.8% of the taken water samples of water cooler dispensers were contaminated with mold or yeast and Escherichia coli, respectively. Conclusion: According to some microbial contamination in water samples of water cooler devices to ensure availability clean water to consumers (students and hospital’s visitors) continuous monitoring, proper maintenance and regular inspection of the water cooler dispensers seems necessary."

Journal of Human, Environment, and Health Promotion

Poor quality of drinking water is one of the main causes of death worldwide (3). Undesirable water quality throughout the world accounts for 1.7 million deaths annually (1.3% of all deaths in the world). The majority of deaths occur in children (nearly 90 percent) due to diarrhea and gastrointestinal diseases most of which happen in developing countries by ingestion of contaminated water. According to the reports of World Health Organization (WHO), 75 percent of human diseases are due to lack of water sanitation and access to safe water for drinking (4, 5).

International Journal of Hygiene and Environmental Health, 2008

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.

The evaluation of the effectiveness of storage as a point-of-use means for improving the bacteriological quality of drinking water was carried out using a completely randomized block design. Total plate and total coliform counts were enumerated for day 0 -10 samples using Nutrient Agar (NA) and multiple tube techniques respectively. Physicochemical analyses of water samples were carried out using standard procedures including titrimetric methods. Ten bacteria species including Escherichia coli, Bacillus cereus, Citrobacter freundil, Salmonella typhymurium, Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae, Arizona spp., Proteus vulgaris, Enterobacter aerogenes were isolated from water samples obtained from borehole, well and sachet water samples in the study area. For day zero samples, it was found that the total bacteria counts ranged from 1.01x10 2 to 4.38 x10 2 CFU/mL for borehole, 0.57x10 2 to 2.13x10 2 CFU/mL for well and 0.54x10 2 to 0.92x10 2 CFU/mL for sachet water. A significant reduction in bacteria load was recorded for all samples from day 2 to day 7 when the water samples were monitored over a period of ten days. The results reveal that water storage for 2-7 days is a viable point-of-use method of household level drinking water disinfection.

2014

Background Drinking water quality can be deteriorated by microbial and toxic chemicals during transport, storage and handling before using by the consumer. This study was conducted to evaluate the microbial and physicochemical quality of drinking water from bottled water coolers. Methods A total of 64 water samples, over a 5-month period in 2012-2013, were collected from free standing bottled water coolers and water taps in Isfahan. Water samples were analyzed for heterotrophic plate count (HPC), temperature, pH, residual chlorine, turbidity, electrical conductivity (EC) and total organic carbon (TOC). Identification of predominant bacteria was also performed by sequence analysis of 16S rDNA. Results The mean HPC of water coolers was determined at 38864 CFU/ml which exceeded the acceptable level for drinking water in 62% of analyzed samples. The HPC from the water coolers was also found to be significantly (P < 0.05) higher than that of the tap waters. The statistical analysis sh...

Food Control, 2013

and sharing with colleagues.

Ceylon Medical Journal, 2012

Introduction People rely on the quality of the bottled drinking water, expecting it to be free of microbial contamination and health hazards.