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.

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 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.

Microbiological Quality of Frozen Cream-Type Pies Sold in Canada

1983 ◽  
Vol 46 (1) ◽  
pp. 34-40 ◽  
Author(s):  
E. C. D. TODD ◽  
G. A. JARVIS ◽  
K. F. WEISS ◽  
G. W. RIEDEL ◽  
S. CHARBONNEAU
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Microbiological Quality ◽  
The United States ◽  
National Guidelines ◽  
E Coli ◽  
Yeasts And Molds

Ten types of frozen cream-type pies, manufactured in Canada and imported from the United States, were analyzed for aerobic colony counts, yeasts and molds, coliforms, Escherichia coli, Staphylococcus aureus and Salmonella. The variations in counts depended more on the manufacturer than on the type of pie and the ingredients used. Five of the 465 examined pies had an excess of 105 aerobic colony counts/g, whereas the median value for all the pies examined was between 102 and 103 CFU/g. E. coli and S. aureus were present in few pies, mainly made by one manufacturer, but there was no correlation between high aerobic colony counts and these organisms. Salmonella was not found in any of the pies. Percentage distributions of the estimated ‘population’ of pies available nationally at the time of the survey were statistically determined. These were then compared with suggested national guidelines in the form of a three-class acceptance plan based on United States surveys and desirable manufacturing practices. These indicate that pies should contain aerobic colony counts of &lt;50,000/g, yeast and mold counts of &lt;500/g, S. aureus counts of &lt;100/g, coliform counts of &lt;50/g, E. coli counts of &lt;10/g, and no Salmonella. Three of the six manufacturers would have had an estimated 5.4 to 32.6% of lots in excess of the guidelines at the time of the survey.

Bacteriological Survey of Frozen Meat Ravioli Produced at Establishments Under Federal Inspection

1983 ◽  
Vol 46 (8) ◽  
pp. 710-713
Author(s):  
DOUGLAS F. CAMPBELL ◽  
MARTHA Y. WORKMAN ◽  
GEORGE W. KRUMM ◽  
RALPH W. JOHNSTON
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Production Line ◽  
Microbiological Quality ◽  
Slow Freezing ◽  
Geometric Means ◽  
E Coli ◽  
Plate Counts ◽  
Product Sets

During visits to 20 federally inspected establishments producing meat ravioli, 577 production line samples and 480 finished product units were collected for bacteriological analyses. Four types of finished, packaged ravioli were encountered: (a) whole ravioli boiled at least 5 min; (b) raw pasta stuffed with a cooked filling; (c) only the meat component cooked; and (d) uncooked ravioli. The microbiological quality of frozen ravioli was affected more by the filling than the pasta. Slow freezing resulted in increased bacterial levels in the finished product. For the boiled ravioli, 100% of the finished product sets contained less than 50 coliforms per g, four of five sets had less than one Escherichia coli per g, and 100% had fewer than one Staphylococcus aureus per g. Four of five sets of packaged boiled ravioli had aerobic plate counts (APC) of less than 10,000 per g. For the raw pasta with a cooked filling-type ravioli, the geometric means of 9 sets were: coliforms, 47 per g; E. coli, 6.7 per g; S. aureus, 10 per g; and APC, 170,000 per g. For the ravioli with only the meat component cooked, the geometric means of 27 sets were: coliforms, 190 per g; E. coli, 1.8 per g; S. aureus, 3.9 per g; and APC, 300,000 per g. For uncooked ravioli, the geometric means of 7 sets were: coliforms, 490 per g; E. coli, 19 per g; S. aureus, 5.7 per g; and APC, 690,000 per g. Only one finished ravioli unit in 480 contained Salmonella.

Broiler Carcass Reprocessing, A Further Evaluation

1993 ◽  
Vol 56 (11) ◽  
pp. 983-985 ◽  
Author(s):  
L. C. BLANKENSHIP ◽  
J. S. BAILEY ◽  
N. A. COX ◽  
M. T. MUSGROVE ◽  
M. E. BERRANG ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Microbiological Quality ◽  
Significant Trend ◽  
Aerobic Bacteria ◽  
E Coli ◽  
Processing Plants ◽  
Processing Line ◽  
Commercial Processing

The microbiological quality of 745 conventionally processed and 745 reprocessed broiler carcasses was determined. Carcasses were taken from the processing line prior to entering the chiller in five commercial processing plants. Each plant was sampled twice during the winter, spring, and summer. Analyses included aerobic bacteria, Enterobacteriaceae, and Escherichia coli counts plus qualitative Salmonella (SAL) prevalence. Differences between overall mean log10 counts for aerobic bacteria, Enterobacteriaceae, and E. coli were not significant. The prevalence of SAL detected on conventionally processed and reprocessed carcasses also was not significantly different. Some variation was observed in microbiological quality of carcasses among processing plants. Although the SAL prevalence appeared to decline from winter to summer replications, no significant trend could be demonstrated. Continuation of the practice of reprocessing carcasses appears justified.

scholarly journals Microbiological Quality of Bagged Cut Spinach and Lettuce Mixes

2007 ◽  
Vol 74 (4) ◽  
pp. 1240-1242 ◽  
Author(s):  
Iris Valentin-Bon ◽  
Andrew Jacobson ◽  
Steven R. Monday ◽  
Peter C. H. Feng
Keyword(s):  
Escherichia Coli ◽  
Microbiological Quality ◽  
Bacterial Counts ◽  
E Coli

ABSTRACT Analysis of 100 bagged lettuce and spinach samples showed mean total bacterial counts of 7.0 log10 CFU/g and a broad range of <4 to 8.3 log10 CFU/g. Most probable numbers (MPN) of ≥11,000 /g coliforms were found in 55 samples, and generic Escherichia coli bacteria were detected in 16 samples, but no E. coli count exceeded 10 MPN/g.

scholarly journals Multiplex Fluorogenic Real-Time PCR for Detection and Quantification of Escherichia coli O157:H7 in Dairy Wastewater Wetlands

2002 ◽  
Vol 68 (10) ◽  
pp. 4853-4862 ◽  
Author(s):  
A. Mark Ibekwe ◽  
Pamela M. Watt ◽  
Catherine M. Grieve ◽  
Vijay K. Sharma ◽  
Steven R. Lyons
Keyword(s):  
Escherichia Coli ◽  
Detection Limit ◽  
The United States ◽  
Dairy Wastewater ◽  
Pcr Assay ◽  
E Coli ◽  
Quality Of Water ◽  
Plate Counts

ABSTRACT Surface water and groundwater are continuously used as sources of drinking water in many metropolitan areas of the United States. The quality of water from these sources may be reduced due to increases in contaminants such as Escherichia coli from urban and agricultural runoffs. In this study, a multiplex fluorogenic PCR assay was used to quantify E. coli O157:H7 in soil, manure, cow and calf feces, and dairy wastewater in an artificial wetland. Primers and probes were designed to amplify and quantify the Shiga-like toxin 1 (stx1) and 2 (stx2) genes and the intimin (eae) gene of E. coli O157:H7 in a single reaction. Primer specificity was confirmed with DNA from 33 E. coli O157:H7 and related strains with and without the three genes. A direct correlation was determined between the fluorescence threshold cycle (CT ) and the starting quantity of E. coli O157:H7 DNA. A similar correlation was observed between the CT and number of CFU per milliliter used in the PCR assay. A detection limit of 7.9 × 10−5 pg of E. coli O157:H7 DNA ml−1 equivalent to approximately 6.4 × 103 CFU of E. coli O157:H7 ml−1 based on plate counts was determined. Quantification of E. coli O157:H7 in soil, manure, feces, and wastewater was possible when cell numbers were ≥3.5 × 104 CFU g−1. E. coli O157:H7 levels detected in wetland samples decreased by about 2 logs between wetland influents and effluents. The detection limit of the assay in soil was improved to less than 10 CFU g−1 with a 16-h enrichment. These results indicate that the developed PCR assay is suitable for quantitative determination of E. coli O157:H7 in environmental samples and represents a considerable advancement in pathogen quantification in different ecosystems.

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