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

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.

Author(s):  
Rehan Deshmukh ◽  
Sunil Bhand ◽  
Utpal Roy

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.


1975 ◽  
Vol 74 (3) ◽  
pp. 431-440 ◽  
Author(s):  
P. A. Ayres

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.


2012 ◽  
Vol 10 (3) ◽  
pp. 243 ◽  
Author(s):  
Hanna Lethycia Wolupeck ◽  
Helen Caroline Raksa ◽  
Luciane Silvia Rossa ◽  
Raquel Biasi ◽  
Renata Ernlund Freitas de Macedo

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.


1977 ◽  
Vol 40 (11) ◽  
pp. 790-794 ◽  
Author(s):  
JAMES F. FOSTER ◽  
JAMES L. FOWLER ◽  
WARREN C. LADIGES

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.


2009 ◽  
Vol 72 (1) ◽  
pp. 197-201 ◽  
Author(s):  
R. J. MELDRUM ◽  
P. T. MANNION ◽  
J. GARSIDE ◽  

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.


1983 ◽  
Vol 46 (1) ◽  
pp. 34-40 ◽  
Author(s):  
E. C. D. TODD ◽  
G. A. JARVIS ◽  
K. F. WEISS ◽  
G. W. RIEDEL ◽  
S. CHARBONNEAU

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.


1983 ◽  
Vol 46 (8) ◽  
pp. 710-713
Author(s):  
DOUGLAS F. CAMPBELL ◽  
MARTHA Y. WORKMAN ◽  
GEORGE W. KRUMM ◽  
RALPH W. JOHNSTON

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.


1993 ◽  
Vol 56 (11) ◽  
pp. 983-985 ◽  
Author(s):  
L. C. BLANKENSHIP ◽  
J. S. BAILEY ◽  
N. A. COX ◽  
M. T. MUSGROVE ◽  
M. E. BERRANG ◽  
...  

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.


2007 ◽  
Vol 74 (4) ◽  
pp. 1240-1242 ◽  
Author(s):  
Iris Valentin-Bon ◽  
Andrew Jacobson ◽  
Steven R. Monday ◽  
Peter C. H. Feng

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.


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