scholarly journals Are the defined substrate-based methods adequate to determine the microbiological quality of natural recreational waters?

2009 ◽  
Vol 8 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Marta Sofia Valente ◽  
Paulo Pedro ◽  
M. Carmen Alonso ◽  
Juan J. Borrego ◽  
Lídia Dionísio
Keyword(s):  
Standard Method ◽  
Membrane Filtration ◽  
Microbiological Quality ◽  
Recreational Waters ◽  
Total Coliforms ◽  
E Coli ◽  
Quality Of Water ◽  
Routine Monitoring ◽  
Rapid Tests

Monitoring the microbiological quality of water used for recreational activities is very important to human public health. Although the sanitary quality of recreational marine waters could be evaluated by standard methods, they are time-consuming and need confirmation. For these reasons, faster and more sensitive methods, such as the defined substrate-based technology, have been developed. In the present work, we have compared the standard method of membrane filtration using Tergitol-TTC agar for total coliforms and Escherichia coli, and Slanetz and Bartley agar for enterococci, and the IDEXX defined substrate technology for these faecal pollution indicators to determine the microbiological quality of natural recreational waters. ISO 17994:2004 standard was used to compare these methods. The IDEXX for total coliforms and E. coli, Colilert®, showed higher values than those obtained by the standard method. Enterolert® test, for the enumeration of enterococci, showed lower values when compared with the standard method. It may be concluded that more studies to evaluate the precision and accuracy of the rapid tests are required in order to apply them for routine monitoring of marine and freshwater recreational bathing areas. The main advantages of these methods are that they are more specific, feasible and simpler than the standard methodology.

Assessment of microbiological quality of drinking water from household tanks in Bermuda

2008 ◽  
Vol 54 (6) ◽  
pp. 495-500 ◽  
Author(s):  
B. Lévesque ◽  
D. Pereg ◽  
E. Watkinson ◽  
J.S. Maguire ◽  
L. Bissonnette ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Membrane Filtration ◽  
Microbiological Quality ◽  
General Information ◽  
Total Coliforms ◽  
E Coli ◽  
Electoral Register ◽  
Highly Correlated

Bermuda residents collect rainwater from rooftops to fulfil their freshwater needs. The objective of this study was to assess the microbiological quality of drinking water in household tanks throughout Bermuda. The tanks surveyed were selected randomly from the electoral register. Governmental officers visited the selected household (n = 102) to collect water samples and administer a short questionnaire about the tank characteristics, the residents’ habits in terms of water use, and general information on the water collecting system and its maintenance. At the same time, water samples were collected for analysis and total coliforms and Escherichia coli were determined by 2 methods (membrane filtration and culture on chromogenic media, Colilert kit). Results from the 2 methods were highly correlated and showed that approximately 90% of the samples analysed were contaminated with total coliforms in concentrations exceeding 10 CFU/100 mL, and approximately 66% of samples showed contamination with E. coli. Tank cleaning in the year prior to sampling seems to protect against water contamination. If rainwater collection from roofs is the most efficient mean for providing freshwater to Bermudians, it must not be considered a source of high quality drinking water because of the high levels of microbial contamination.

scholarly journals Microbiological quality of shellfish and evaluation of compact dry EC for detecting total coliforms and Escherichia coli

2020 ◽  
Vol 49 (1) ◽  
pp. 32-39 ◽  
Author(s):  
A. Vásquez García ◽  
S.H. Gomes de Sá ◽  
G. de Sousa Silva ◽  
J.E. Mejia Ballesteros ◽  
E. Barbieri ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Conventional Method ◽  
Microbiological Quality ◽  
Correlation Coefficients ◽  
Mean Values ◽  
Total Coliforms ◽  
E Coli ◽  
The Mean

The objective of this study was to evaluate the microbiological quality of oysters and mussels grown in Cananéia, Brazil, by analysing mesophiles, psychrothophic bacteria, moulds and yeasts, Staphylococcus aureus, and Salmonella spp., and to compare the efficiency of Compact Dry EC method and the conventional method for counting of total coliforms and Escherichia coli. The microbial analysis showed that the mean values of mesophilic counts were 3.14±0.81 log CFU g−1 for oysters and 3.92±0.90 for mussels; the mean values of psychrophilic counts were 2.78±0.75 log CFU g−1 for oysters and 3.22±0.75 log CFU g−1 for mussels; the mean values of mould and yeast counts were 3.70±0.58 log CFU g−1 for oysters and 3.33±0.81 log CFU g−1 for mussels. Salmonella spp. did not present positive results, and the maximal count of Staphylococcus aureus was 1.7 log CFU g−1, therefore, within the limits established in the legislation. The correlation coefficients between the Compact Dry EC method and conventional method were >0.87 for total coliform and E. coli counts for both types of shellfish. The data in this study show that the Compact Dry EC method is an acceptable alternative to conventional methods for enumeration of total coliforms and E. coli in shellfish.

scholarly journals Indicator of Quality of Water for Human Consumption in the Community El Comején, Masaya (Nicaragua)

2019 ◽  
Vol 11 (8) ◽  
pp. 176
Author(s):  
Dixon Nohel Morales López ◽  
Ismael Montero Fernández ◽  
Selvin Antonio Saravia Maldonado ◽  
Francisco Luis Acosta Díaz ◽  
Luis Antonio Beltrán Alemán
Keyword(s):  
Major Element ◽  
Poor Quality ◽  
Human Consumption ◽  
Total Coliforms ◽  
E Coli ◽  
The Poor ◽  
Quality Of Water ◽  
Sampling Points ◽  
The Republic

Knowing the quality of water for human consumption is of utmost importance in the development of a country, since the poor quality of this vital liquid can be a source of diseases for the health of the population. The present work was carried out in the community El Comején, Masaya, in the Republic of Nicaragua, where microbiological analyzes were carried out in three sampling points (one well drilled and two taps). The physicochemical and chemical analyzes are in accordance with the norms established by CARPE, highlighting sodium as a major element with a concentration of 48.6 mg L-1 and potassium with 21.08 mg L-1. On the other hand, biological parameters such as total coliforms, thermotolerable coliforms, E. coli and fecal enterococos were analyzed, being found in some sampling points, values of total coliforms of 110 NMP 100 mL-1 being above the established limits, requiring a treatment additional to be suitable for human consumption.

scholarly journals The effect of container-biofilm on the microbiological quality of water used from plastic household containers

2003 ◽  
Vol 1 (3) ◽  
pp. 101-108 ◽  
Author(s):  
P. Jagals ◽  
C. Jagals ◽  
T. C. Bokako
Keyword(s):  
Heterotrophic Bacteria ◽  
Microbiological Quality ◽  
Total Coliform ◽  
Human Consumption ◽  
Microbiological Contamination ◽  
Supply Source ◽  
E Coli ◽  
Quality Of Water ◽  
Storage Containers

Studies in Southern Africa have shown that even when microbiologically safe water is supplied to developing communities at communal standpipes, contamination by high numbers of pathogenic microorganisms may occur during the processes of fetching water from the supply source and storage during use at home, rendering such waters unsafe for human consumption. This study investigated the occurrence of biofilm in PVC storage containers as one possible reason for this deterioration, using heterotrophic bacteria and total coliform counts as well as turbidity as indicators. A second objective was to determine whether biofilm in water-storage containers could contribute to hazardous microbiological contamination indicated by Escherichia coli and Clostridium perfringens. Results indicated that increased microbiological contamination is associated with biofilm. The biofilm harbours heterotrophic bacteria, total coliforms and C. perfringens. E. coli could not be associated directly with the levels of biofilm in containers but rather appears to be introduced intermittently from the ambient domestic environment. When dislodged with the biofilm, these bacteria contributed substantially to the deterioration of the microbiological quality of supplied water stored in plastic containers.

Effect of climate changes on waterborne disease in The Netherlands

2005 ◽  
Vol 51 (5) ◽  
pp. 79-87 ◽  
Author(s):  
J.F. Schijven ◽  
A.M. de Roda Husman
Keyword(s):  
Drinking Water ◽  
The Netherlands ◽  
Microbiological Quality ◽  
Residence Times ◽  
Waterborne Pathogens ◽  
Recreational Waters ◽  
Pumping Rate ◽  
Quality Of Water ◽  
Drinking Water Production

Effects of climate change in The Netherlands in the 21st century on the microbiological quality of water for drinking water production and recreation were evaluated. The following was concluded: increased temperature leads to significant additional inactivation of enteric pathogens in surface waters with residence times of more than a month, but not in waters with residence times of up to ten days. Increased precipitation, runoff and storm water overflow lead to more peak concentrations of waterborne pathogens in surface water. Peak concentrations strongly determine the infection risk through drinking water consumption. Drought lowers and increased precipitation elevates groundwater tables, but an effect on the risk of groundwater contamination with waterborne pathogens is not clear. Climate effects are not noticeable near a groundwater well, where the groundwater table and flow rate are mainly determined by the pumping rate. Exposure of recreants to waterborne pathogens that can grow in the water is expected to increase due to increased recreation and increased growth opportunities of these pathogens. Due to warmer summers, pathogens, like amoeba, that have not caused problems up to date in The Netherlands, may now emerge in recreational waters.

scholarly journals Statistical Analyses: Possible Reasons for Unreliability of Source Tracking Efforts

2005 ◽  
Vol 71 (8) ◽  
pp. 4690-4695 ◽  
Author(s):  
Clarivel Lasalde ◽  
Roberto Rodríguez ◽  
Gary A. Toranzos
Keyword(s):  
Cluster Analysis ◽  
Discriminant Function ◽  
Discriminant Function Analysis ◽  
Function Analysis ◽  
Microbiological Quality ◽  
Statistical Analyses ◽  
Indicator Organisms ◽  
E Coli ◽  
Quality Of Water

ABSTRACT Analyses for the presence of indicator organisms provide information on the microbiological quality of water. Indicator organisms recommended by the United States Environmental Protection Agency for monitoring the microbiological quality of water include Escherichia coli, a thermotolerant coliform found in the feces of warm-blooded animals. These bacteria can also be isolated from environmental sources such as the recreational and pristine waters of tropical rain forests in the absence of fecal contamination. In the present study, E. coli isolates were compared to E. coli K12 (ATCC 29425) by restriction fragment length polymorphism using pulsed-field gel electrophoresis. Theoretically, genomic DNA patterns generated by PFGE are highly specific for the different isolates of an organism and can be used to identify variability between environmental and fecal isolates. Our results indicate a different band pattern for almost every one of the E. coli isolates analyzed. Cluster analysis did not show any relations between isolates and their source of origin. Only the discriminant function analysis grouped the samples with the source of origin. The discrepancy observed between the cluster analysis and discriminant function analysis relies on their mathematical basis. Our validation analyses indicate the presence of an artifact (i.e., grouping of environmental versus fecal samples as a product of the statistical analyses used and not as a result of separation in terms of source of origin) in the classification results; therefore, the large genetic heterogeneity observed in these E. coli populations makes the grouping of isolates by source rather difficult, if not impossible.

Microbiological Quality of Water Immersion–Chilled and Air-Chilled Broilers

2011 ◽  
Vol 74 (9) ◽  
pp. 1531-1535 ◽  
Author(s):  
LEI ZHANG ◽  
JONG Y. JEONG ◽  
KISHOREKUMAR K. JANARDHANAN ◽  
ELLIOT T. RYSER ◽  
IKSOON KANG
Keyword(s):  
Water Immersion ◽  
Cetylpyridinium Chloride ◽  
Microbiological Quality ◽  
E Coli ◽  
Quality Of Water ◽  
Spoilage Bacteria ◽  
Processing Line ◽  
Commercial Processing ◽  
On Farm

Carcass chilling during broiler processing is a critical step in preventing growth of pathogenic and spoilage bacteria. The objective of this study was to compare the microbiological quality of air- and water-chilled broiler carcasses processed at the same commercial facility. For each of four replications, 15 broilers were collected from the same commercial processing line after evisceration, after spraying with cetylpyridinium chloride (a cationic disinfectant), and after air chilling or water immersion chilling (WIC). All carcasses were quantitatively examined for mesophilic aerobic bacteria, Escherichia coli, coliforms, and Campylobacter as well as for the presence of Salmonella and Campylobacter. No significant differences (P > 0.05) were seen between air and water chilling for E. coli or coliforms or for the incidence of Salmonella and Campylobacter. Lower numbers of Campylobacter were recovered from WIC than from air-chilled carcasses (P < 0.05), but the incidence of Campylobacter on WIC carcasses was similar, suggesting that some Campylobacter organisms were injured rather than killed during WIC. In-line spraying with the disinfectant effectively decreased the incidence of Salmonella and Campylobacter on prechilled carcasses; however, cells presumably injured by the sanitizer recovered during chilling. Therefore, on-farm intervention strategies remain critically important in minimizing the spread of microbial contaminants during processing.

scholarly journals Management of Microbiological Contamination of the Water Network of a Newly Built Hospital Pavilion

Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 75
Author(s):  
Osvalda De Giglio ◽  
Giusy Diella ◽  
Marco Lopuzzo ◽  
Francesco Triggiano ◽  
Carla Calia ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Microbiological Quality ◽  
Silver Ions ◽  
Waterborne Diseases ◽  
Water Safety ◽  
Water Network ◽  
E Coli ◽  
Quality Of Water ◽  
Water Safety Plan

The good installation, as well as commissioning plan, of a water network is a crucial step in reducing the risk of waterborne diseases. The aim of this study was to monitor the microbiological quality of water from a newly built pavilion before it commenced operation. Overall, 91 water samples were tested for coliforms, Escherichia coli, enterococci, Pseudomonas aeruginosa and Legionella at three different times: T0 (without any water treatment), T1 (after treatment with hydrogen peroxide and silver ions at initial concentration of 20 mg/L and after flushing of water for 20 min/day for seven successive days) and T2 (15 days later). Coliforms were detected in 47.3% of samples at T0, 36.3% at T1 and 4.4% at T2. E. coli was isolated in 4.4% of the samples only at T1, while enterococci appeared in 12.1% of the samples at T1 and in 2.2% at T2. P. aeruginosa was isolated in 50.5% of the samples at T0, 29.7% at T1 and 1.1% at T2. Legionella pneumophila serogroup 8 was isolated in 80.2% of the samples at T0, 36.3% at T1 and 2.2% at T2. Our results confirmed the need for a water safety plan in new hospital pavilions to prevent the risk of waterborne diseases.

Mineral water: a microbiological approach

2012 ◽  
Vol 12 (5) ◽  
pp. 556-562 ◽  
Author(s):  
Maria Fernanda Falcone-Dias ◽  
Guilherme L. Emerick ◽  
Adalberto Farache-Filho
Keyword(s):  
Mineral Water ◽  
Microbiological Quality ◽  
Public Health Problem ◽  
Quality Standard ◽  
Plate Count ◽  
Important Public Health Problem ◽  
Total Coliforms ◽  
E Coli ◽  
Bottled Mineral Water

The microbiological quality of bottled mineral water of various domestic brands sold in Brazil was investigated, with particular focus on the heterotrophic plate count (HPC). Neither total coliforms nor Escherichia coli were found in any 1.5 L bottle samples. Total coliforms were found in 2.9% of the small bottles, while in 20 L bottles the presence of total coliforms and E. coli was demonstrated in 15.5 and 2.4% of samples, respectively. Pseudomonas aeruginosa was detected in 4.3, 4.5 and 9.5% of small, 1.5 and 20 L bottles, respectively. In 36.4% of the samples of 1.5 L bottles, the HPC was above 500 cfu/mL. This percentage of samples with an HPC above 500 cfu/mL increased to 52.0 and 61.9% in small and 20 L bottles, respectively. Higher contamination by total coliforms, E. coli, P. aeruginosa and HPCs occurred in 20 L bottles. In conclusion, several samples in this study were outside the international quality standard for mineral water and the large number of samples with high HPCs shows that more work must be done on the use of HPC in mineral water and the damaging effects that these microorganisms may cause to humans. The bottled mineral water was confirmed as a particularly important public health problem, due to the poor microbiological quality of the products that are marketed.

scholarly journals Microbiological quality of raw drinking milk and unpasteurised dairy products: results from England 2013–2019

2020 ◽  
Vol 148 ◽  
Author(s):  
J. McLauchlin ◽  
H. Aird ◽  
A. Elliott ◽  
E. Forester ◽  
F. Jørgensen ◽  
...  
Keyword(s):  
Dairy Products ◽  
Microbiological Quality ◽  
The Public ◽  
E Coli ◽  
Routine Monitoring ◽  
Drinking Milk ◽  
Coagulase Positive Staphylococci ◽  
Raw Cow’S Milk ◽  
Milk And Dairy Products

Abstract The aim of this study was to review microbiology results from testing >2500 raw drinking milk and dairy products made with unpasteurised milk examined in England between 2013 and 2019. Samples were collected as part of incidents of contamination, investigation of infections or as part of routine monitoring and were tested using standard methods for a range of both pathogens and hygiene indicators. Results from testing samples of raw cow's milk or cheese made from unpasteurised milk for routine monitoring purposes were overall of better microbiological quality than those collected during incident or investigations of infections. Results from routine monitoring were satisfactory for 62% of milks, 82% of cream, 100% of ice-cream, 51% of butter, 63% of kefir and 79% of cheeses, with 5% of all samples being considered potentially hazardous. Analysis of data from cheese demonstrated a significant association between increasing levels of indicator Escherichia coli with elevated levels of coagulase positive staphylococci and decreased probability of isolation of Shiga toxin-producing E. coli. These data highlight the public health risk associated with these products and provide further justification for controls applied to raw drinking milk and dairy products made with unpasteurised milk.

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