scholarly journals BCIG-SMAC medium and PMA-qPCR for differential detection of viable Escherichia coli in potable water

2021 ◽  
Author(s):  
Rehan Deshmukh ◽  
Sunil Bhand ◽  
Utpal Roy
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Water Samples ◽  
Potable Water ◽  
Microbiological Quality ◽  
Differential Detection ◽  
Filtration Method ◽  
E Coli ◽  
Quality Of Water

Background and Objectives: Public health protection requires timely evaluation of pathogens in potable water to minimize outbreaks caused by microbial contaminations. The present study was aimed at assessing the microbiological quality of water obtained from Shantinagar (a rural area in the South Goa region of Goa, India) using 5-Bromo-4-Chloro-3-Indoxyl β-D-glu- curonide-Sorbitol MacConkey agar (BCIG-SMAC) medium and, propidium monoazide-quantitative polymerase chain reac- tion (PMA-qPCR) assay for differential detection and quantification of viable Escherichia coli cells in water samples. Materials and Methods: Membrane filtration method was used for both BCIG-SMAC medium and PMA-qPCR methods. To determine the efficiency of detection of viable cells, we first evaluated the PMA treatment protocol and established the standard calibration curves using previously reported primers. Results: PMA-qPCR detected as low as 7 femtograms of DNA of E. coli per qPCR reaction whereas the limit of detection (LOD) of BCIG-SMAC medium was 1.8 CFU/100mL. A total of 71 water samples spanning 2017-2018 have been analyzed using BCIG-SMAC medium and PMA-qPCR, of which 95.77% (68/71) and 7.04% (5/71) were found to be total E. coli and E. coli O157:H7, respectively. PMA-qPCR study showed the viable counts of total viable E. coli cells ranging from 3CFU/100mL to 8.2×102 CFU/100mL. The total E. coli CFU/100mL quantified by PMA-qPCR significantly exceeded (paired t-test; P<0.05) the number on BCIG-SMAC medium. Conclusion: The present study indicates that the microbiological quality of environmental water samples analyzed do not comply with the regulatory standard. Therefore, special attention is warranted to improve the overall portable quality of water in the perspective of public health.

scholarly journals Diversity, virulence and antibiogram traits of Escherichia coli recovered from potable water sources in Gharbia, Egypt

2020 ◽  
Vol 18 (3) ◽  
pp. 430-438
Author(s):  
Walid Elmonir ◽  
Etab Mohamed Abo Remela ◽  
Yasmine Alwakil
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Water Samples ◽  
Potable Water ◽  
Multiple Drug Resistance ◽  
Tap Water ◽  
Water Sources ◽  
Multiple Drug ◽  
Well Water ◽  
E Coli

Abstract This study aimed to assess the public health risk of coliforms and Escherichia coli contamination of potable water sources in Egypt. A total of 150 water samples (100 tap and 50 well) were collected from five districts in Gharbia governorate, Egypt. High rates of coliforms contamination were recorded in 52 and 76% of examined tap and well water samples, respectively. E. coli strains were detected in 16% of the water samples (15% tap water and 18% well water; 23.7% rural and 8.1% urban). Rural water sources were 3.5 times more likely to be contaminated than urban sources (P = 0.01). Eight (33.3%) E. coli isolates were Shiga toxin-producing E. coli (STEC). Multiple drug resistance (MDR) was observed for 62.5% of the isolates. Seven (29.2%) E. coli isolates harboured at least one of the extended-spectrum beta-lactamase (ESBL) genes. The majority (87.5%) of the STEC isolates were MDRs and harboured ESBL genes. STEC isolates were significantly more likely to resist six classes of antibiotics than non-STEC isolates. This is the first report of potable water contamination with MDR-STEC in Egypt. This study highlights an alarming public health threat that necessitates preventive interventions for public and environmental safety.

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

2000 ◽  
Vol 124 (3) ◽  
pp. 417-425 ◽  
Author(s):  
M. RUTTER ◽  
G. L. NICHOLS ◽  
A. SWAN ◽  
J. DE LOUVOIS
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Water Quality ◽  
Uv Light ◽  
Microbiological Quality ◽  
Light Treatment ◽  
Water Supplies ◽  
The Public ◽  
E Coli

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.

scholarly journals Evidence for Coexistence of Distinct Escherichia coli Populations in Various Aquatic Environments and Their Survival in Estuary Water

2013 ◽  
Vol 79 (15) ◽  
pp. 4684-4693 ◽  
Author(s):  
T. Berthe ◽  
M. Ratajczak ◽  
O. Clermont ◽  
E. Denamur ◽  
F. Petit
Keyword(s):  
Escherichia Coli ◽  
Microbiological Quality ◽  
Physicochemical Characteristics ◽  
Point Sources ◽  
Fecal Bacteria ◽  
Content Type ◽  
E Coli ◽  
Quality Of Water ◽  
Bodies Of Water

ABSTRACTEscherichia coli, a commensal bacterium from the intestinal tracts of humans and vertebrate animals, has been used as one of two bacterial indicators of fecal contamination, along with intestinal enterococci, to monitor the microbiological quality of water. However, water environments are now recognized as a secondary habitat where some strains can survive. We investigated the survival ofE. coliisolates collected from bodies of water in France exhibiting distinct profiles of contamination, defined according to the following criteria: vicinity of the point sources of contamination, land use, hydrology, and physicochemical characteristics of the receiving water. We selected 88E. colistrains among a collection of 352 strains to carry out a microcosm experiment in filtered estuarine water for 14 days at 10°C. The relationship between the survival ofE. colistrains and genotypic and phenotypic characteristics was analyzed. This work showed that distinctE. colisurvival types, able to survive from between 7 and 14 days to less than 2 days, coexisted in the water.E. coliisolates that rapidly lost their culturability were more frequently isolated in water recently contaminated by fecal bacteria of human origin, and most were multiresistant to antibiotics and harbored several virulence factors. In contrast, persistent strains able to survive from 4 to 14 days were more often found in water with low levels of fecal bacteria, belonged mainly to the B1 phylogroup, often harbored only one virulence factor,kspEorompT, and were able to grow at 7°C.

An Improved Membrane Filtration Method for Enumeration of Faecal Coliforms and E. Coli by a Fluorogenic β-Glucuronidase Assay

1993 ◽  
Vol 27 (3-4) ◽  
pp. 267-270 ◽  
Author(s):  
M. T. Augoustinos ◽  
N. A. Grabow ◽  
B. Genthe ◽  
R. Kfir
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
Membrane Filtration ◽  
Faecal Coliforms ◽  
Environmental Waters ◽  
Filtration Method ◽  
E Coli ◽  
Wide Range ◽  
Pure Cultures ◽  
Glucuronidase Assay

A fluorogenic β-glucuronidase assay comprising membrane filtration followed by selective enumeration on m-FC agar at 44.5°C and further confirmation using tlie 4-metliylumbelliferyl-β-D-glucuronide (MUG) containing medium was evaluated for the detection of Escherichia coli in water. A total of 200 typical blue and non-typical blue colonies were isolated from sea and fresh water samples using initial selective enumeration on m-FC agar. Pure cultures of the selected colonies were further tested using the MUG assay and identified using the API 20E method. Of the colonies tested which were shown to be positive using the MUG assay 99.4% were Escherichia coli. The results of this study indicate the combination of the m-FC method followed by the MUG assay to be highly efficient for the selection and confirmation of E. coli from a wide range of environmental waters.

scholarly journals The quantitative bacteriology of some commercial bivalve shellfish entering British markets

1975 ◽  
Vol 74 (3) ◽  
pp. 431-440 ◽  
Author(s):  
P. A. Ayres
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Health Risk ◽  
E Coli ◽  
Accepted Standard ◽  
Plate Counts ◽  
Bivalve Shellfish ◽  
Faecal Streptococci ◽  
Specific Illness

SUMMARYIncidents of non-specific illness associated with the consumption of oysters have highlighted the lack of published information on the bacteriology of shellfish suitable for consumption. Investigations showed that the majority of molluscan shellfish entering English markets conform to the accepted standard of less than 5 Escherichia coli/ml. tissue. The numbers of E. coli were related to the sanitary quality of the growing area but no relation could be established between numbers of E. coli and coliforms, faecal streptococci or Clostridium welchii. The numbers of non-specific bacteria varied considerably but shellfish from sources associated with non-specific illness yielded relatively high counts at 37° C. The results showed that there was no justification for a standard based on total plate counts, which often exceeded 106/g. Such a standard would have to be coupled with spoilage or the incidence of non-specific illness. The relation between the numbers of non-specific bacteria growing at 20 and 37° C. appears to be a useful measure for assessing the likelihood that raw shellfish are a public health risk.

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.

scholarly journals EVOLUÇÃO DA QUALIDADE MICROBIOLÓGICA DE QUEIJO MINAS FRESCAL COMERCIALIZADO EM CURITIBA (PR) NO INTERVALO DE 10 ANOS (1999 E 2009) Assessment of the microbiological quality of Minas frescal cheese commercialized in the city of Curitiba, Parana State, Brazil at 10 years’ interval (1999 and 2009)

2012 ◽  
Vol 10 (3) ◽  
pp. 243 ◽  
Author(s):  
Hanna Lethycia Wolupeck ◽  
Helen Caroline Raksa ◽  
Luciane Silvia Rossa ◽  
Raquel Biasi ◽  
Renata Ernlund Freitas de Macedo
Keyword(s):  
Escherichia Coli ◽  
Microbiological Quality ◽  
Salmonella Spp ◽  
E Coli ◽  
The City

O queijo Minas frescal é um dos mais populares do Brasil, porém o alto teor de umidade associado ao métodode processamento, muitas vezes artesanal, e de armazenamento desse produto o tornam muito perecível.Este trabalho teve como objetivo avaliar e comparar a qualidade microbiológica de queijo Minas frescalcomercializado na cidade de Curitiba (PR) nos anos de 1999 e 2009, verificando a evolução na qualidadehigiênico-sanitária desse produto no período de 10 anos. Foram analisadas 11 marcas comerciais de queijo Minas frescal disponíveis no comércio varejista da cidade de Curitiba, sendo amostradas cinco unidades de cada marca, totalizando 55 amostras. Os queijos foram submetidos à pesquisa de Salmonella spp., contagem de coliformes totais e Escherichia coli, contagem de Staphylococcus coagulase positiva e contagem de aeróbios mesófilos, com resultados expressos em UFC/g. Das 55 amostras de queijo, 41,82% e 78,18% apresentaram contagem de E. coli e de coliformes totais acima do limite permitido, respectivamente. Somente uma amostra (1,82%) do total avaliado mostrou-se em desacordo com os padrões para S. coagulase positiva e uma para Salmonella spp. Ambas as amostras foram adquiridas em 2009. Todas as amostras avaliadas em 2009 apresentaram elevada contagem de aeróbios mesófilos, revelando alta carga microbiana. Comparativamente, os queijos avaliados em 1999 mostraram qualidade microbiológica superior aos queijos avaliados em 2009 (p < 0,05). Destes, 100% apresentaram no mínimo um parâmetro microbiológico em desacordo com a legislação vigente, indicando que a qualidade dos queijos Minas frescal avaliados em 2009 apresentou-se inferior a dos queijos avaliados em 1999.

A Bacteriological Survey of Raw Ground Beef1

1977 ◽  
Vol 40 (11) ◽  
pp. 790-794 ◽  
Author(s):  
JAMES F. FOSTER ◽  
JAMES L. FOWLER ◽  
WARREN C. LADIGES
Keyword(s):  
Escherichia Coli ◽  
Microbiological Quality ◽  
Retail Store ◽  
Most Probable Number ◽  
Probable Number ◽  
E Coli ◽  
Fecal Streptococci ◽  
Plate Counts ◽  
Aerobic And Anaerobic

The microbiological quality of 150 units of raw ground beef obtained from a local retail store was determined. The range of aerobic plate counts was from 6.9 × 104 to 8.3 × 107/g. By using the most probable number method 96.7% of the 150 units were positive for coliforms, 94.7% for Escherichia coli and 61.3% for Staphylococcus aureus. By the plate methods, 99.3% of the units were positive for fecal streptococci and 56% were positive for Clostridium perfringens. No salmonellae were isolated. Aerobic and anaerobic organisms were isolated and identified. E. coli was the most frequently isolated aerobe followed by organisms in the Klebsiella-Enterobacter group. Among the anaerobic isolates, C. perfringens was the organism most frequently encountered.

scholarly journals Isolation and Enumeration of Escherichia coli from Soil and Water

2020 ◽  
Vol 36 (2) ◽  
pp. 75-77
Author(s):  
Anindita Bhowmik ◽  
Sunjukta Ahsan
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
Gas Production ◽  
Soil Samples ◽  
Most Probable Number ◽  
Biochemical Tests ◽  
Probable Number ◽  
E Coli ◽  
Dilution Series

Majority of the population of Bangladesh depend on tap or surface water as their source of water supply. This study was carried out to examine the microbial quality of both water and soil collected from different places using the multiple tube fermentation technique to determine coliform count by the most probable number (MPN) method in brilliant green lactose broth (BGLB) media.Inoculum from positive tubes of the presumptive test were further transferred on eosinemethylene blue (EMB) and MacConkey agar.The organisms isolated were further characterized using biochemical tests. Out of 93 water samples, 30 (32.26%) indicated the presence of lactose fermenter and gas producer in all 3 tubes of dilution series using inoculum quantities of 1.0, 0.1 and 0.01 ml, whereas out of 85 soil samples, 45 (52.94%) showed acid and gas production in all 3 tubes of dilution series.Among 85 soil samples, 40 samples that contained at least one positive in each dilution series and among 93 water samples, 31 samples that contained at least one positive in each dilution series were further re-identified with biochemical tests.This study showed 30.59% soil isolates and 26.88% water isolates were Escherichia coli which highlighted the fact that both water and soil act as a major reservoir of E.coli, which indicates possible fecal contamination as well as presence of potentially pathogenic E. coli. Bangladesh J Microbiol, Volume 36 Number 2 December 2019, pp 75-77

Microbiological Quality of Ready-to-Eat Food Served in Schools in Wales, United Kingdom

2009 ◽  
Vol 72 (1) ◽  
pp. 197-201 ◽  
Author(s):  
R. J. MELDRUM ◽  
P. T. MANNION ◽  
J. GARSIDE ◽  
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
United Kingdom ◽  
Clostridium Perfringens ◽  
Microbiological Quality ◽  
Laboratory Service ◽  
The United Kingdom ◽  
Quality Of Food

A survey of the general microbiological quality of ready-to-eat food served in schools was undertaken across Wales, United Kingdom. Of the 2,351 samples taken, four were identified as containing unsatisfactory counts of Escherichia coli, four contained unsatisfactory counts of Staphylococcus aureus, and one contained an unacceptable count of Bacillus cereus when compared with guidelines for the microbiological quality of ready-to-eat food published by the United Kingdom Public Health Laboratory Service in 2000. No samples contained detectable levels of Salmonella, Listeria species, or Clostridium perfringens. When compared with data on the general microbiological quality of food available in Wales, the food sampled from schools was of relatively better microbiological quality.

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