Acceptability of Individual Water Supplies as Judged by a Single Test for Total Coliform Bacteria

1980 ◽  
Vol 43 (7) ◽  
pp. 563-563
Author(s):  
E. P. MERRILL
Keyword(s):  
Membrane Filter ◽  
Total Coliform ◽  
Coliform Bacteria ◽  
Most Probable Number ◽  
Filter Method ◽  
Single Test ◽  
Water Supplies ◽  
Probable Number ◽  
Dug Wells ◽  
Membrane Filter Method

Of 658 individual water supplies tested over an 8-year period, 69% of drilled wells, 62% of driven wells, 27% of dug wells and 32% of springs were judged acceptable on the basis of a single test for total coliforms. The acceptability standard consisted of 0 to 1 coliforms/100 ml of sample by the membrane filter method or a Most Probable Number index of less than 2.2 (presumptive and confirmed tests).

Membrane Filter Method Based on FC-5-Bromo-4-Chloro-3-lndolyl-β-d-Glucuronide Medium Facilitates Enumeration of Escherichia coli in Foods and Poultry Carcass Rinses

1998 ◽  
Vol 61 (3) ◽  
pp. 360-364 ◽  
Author(s):  
A. N. SHARPE ◽  
L. J. PARRINGTON
Keyword(s):  
Escherichia Coli ◽  
Membrane Filter ◽  
Most Probable Number ◽  
Filter Method ◽  
Simple Method ◽  
Probable Number ◽  
E Coli ◽  
Membrane Filter Method ◽  
Alfalfa Sprouts ◽  
Bean Sprouts

Three enumeration methods for Escherichia coli in foods, the Health Protection Branch most-probable-number (MPN) method MFHPB-19, a hydrophobic grid membrane filter method MFHPB-26 (HGMF-indole), and a hydrophobic grid membrane filter method utilizing 5-bromo-4-chloro-3-indolyl-β-d-glucuronide in a (modified) mFC agar (HGMF-FC-BCIG) were compared in 80 food samples that included naturally and artificially contaminated raw vegetables, mung bean and alfalfa sprouts, raw meats, and chicken carcass rinses. The number of samples confirmed as positive for E. coli were 44, 36, and 42 for the MPN, HGMF-indole, and HGMF-FC-BCIG methods, respectively. By the MPN method, E. coli was detected in 3 samples at levels below the limits of detection of the HGMFs; but the MPN method was very time-consuming. With the HGMF-indole procedure E. coli was missed in 4 artificially contaminated samples. With the HGMF-FC-BCIG method E. coli was enumerated in 1 sample of bean sprouts missed by both the MPN and HGMF-indole procedures. High levels of indole-positive Klebsiella spp. in bean sprouts interfered with the HGMF-indole method, but the blue colonies of E. coli were easily observed in the HGMF-FC-BCIG method. Specificity of the HGMF-FC-BCIG method is high enough that routine confirmation should be unnecessary; however, confirmation of presumptive E. coli is easier since no lethal indole-staining step is involved. It appears to be a very simple method for quantifying E. coli in foods or carcass rinses.

Collaborative study of the MPN, Anderson–Baird-Parker direct plating, and hydrophobic grid-membrane filter methods for the enumeration of Escherichia coli biotype I in foods

1983 ◽  
Vol 29 (10) ◽  
pp. 1247-1252 ◽  
Author(s):  
A. N. Sharpe ◽  
M. K. Rayman ◽  
D. M. Burgener ◽  
D. Conley ◽  
A. Loit ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Filter ◽  
Collaborative Study ◽  
Most Probable Number ◽  
Filter Method ◽  
Green Beans ◽  
Probable Number ◽  
Direct Plating ◽  
Filter Methods ◽  
Membrane Filter Method

Five Health Protection Branch laboratories compared two membrane filter methods (the Anderson–Baird-Parker direct plating, and a hydrophobic grid-membrane filter method) against the most probable number procedure (MPN) for enumerating Escherichia coli biotype I in foods. Results were available in 24 h by both membrane filter methods, compared with 10–14 days by the MPN procedure. For ground beef, Parmesan cheese, and cut green beans, the hydrophobic grid method generally gave the highest recovery, although the two membrane filter methods were not significantly different. Both these methods gave significantly higher recoveries than the MPN procedure, and for most foods, either method would be preferable. Further work is required before either membrane filter method can be recommended for bean and alfalfa sprouts, which may contain very high levels of Klebsiella spp.

scholarly journals Bacteriological quality of water in private wells and boreholes in Makurdi Metropolis, Benue State, Nigeria

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Ruth Adi Agyo ◽  
Raph Agbo Ofukwu ◽  
Anthony Ekle J. Okoh ◽  
Charity A. Agada
Keyword(s):  
Water Samples ◽  
Urban Areas ◽  
Total Coliform ◽  
World Health ◽  
Coliform Bacteria ◽  
Most Probable Number ◽  
Probable Number ◽  
Coliform Count ◽  
Significant Difference ◽  
Private Wells

Aim: This study aimed at examined the presence of coliform bacteria in private wells and boreholes (BH) in peri-urban areas of Makurdi, Benue State, Nigeria, using the approaches of most probable number (MPN) index and coliform count. Materials and Methods: Seven hundred and sixty-eight water samples were randomly collected during a 1-year period from non-cased wells, burn brick cased wells (BBW), concrete cased wells, and BH in four locations; A, B, C, and D during the wet and dry seasons. One liter of water was obtained from each well at every visit to the four sites, and eight water samples were collected from each visit. The samples were analyzed using multiple tube fermentation methods and pour plate techniques to determine the MPN of coliform/100 ml of water, reading from the MPN statistics table. Results: One-way analysis of variance statistics was applied using Duncan's new multiple range test to separate the means where there was a significant difference. The result revealed that the MPN index and total coliform counts in all the wells in the locations were above the World Health Organization (WHO) permissible limit for potable water. The highest MPN index of 54.807 was recorded in Location A and followed by 42.679 in Location B. The MPN index in Locations C and D was 36.740 and 30.943, respectively. There was significantly (p=0.000) higher total coliform count in the wet season (41.48±7.09) than in the dry season (38.33±2.83). Conclusion: This study shows the presence of coliform bacteria isolates in all the wells and BH that exceeded the WHO permissible limits for drinking water. The water from these sources is unsafe for drinking except after dosing with appropriate germicides. Sensitization of the population on the actions they can take to make the water safe for domestic use is suggested.

ColiComplete® Substrate-Supporting Disc Method for Confirmed Detection of Total Coliforms and Escherichia coli in All Foods: Comparative Study

1994 ◽  
Vol 77 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Philip T Feldsine ◽  
Maria T Falbo-Nelson ◽  
David L Hustead
Keyword(s):  
Escherichia Coli ◽  
Comparative Study ◽  
Total Coliform ◽  
Coliform Bacteria ◽  
Most Probable Number ◽  
Probable Number ◽  
Total Coliforms ◽  
E Coli ◽  
Total Coliform Bacteria ◽  
Better Than

Abstract The ColiComplete® substrate-supporting disc (SSD) method for simultaneous confirmed total coliform count and Escherichia coli determination in all foods was compared with the AOAC most probable number (MPN) methods 966.23 and 966.24. In this comparative study, 20 water and food types were analyzed; 7 of these foods were naturally contaminated with coliform bacteria, 6 food types were naturally contaminated with E. coli, and the remaining foods were inoculated with coliform bacteria and/or E. coli. Data were analyzed separately for total coliform bacteria and for E. coli. Mean log MPN counts were determined by the SSD method and the appropriate AOAC MPN procedure. Results were then analyzed for mean log MPN differences and variance, according to methods described by AOAC INTERNATIONAL Results for both total conforms and E. coli indicate that the SSD method is equivalent to or better than AOAC MPN methods 966.23 and 966.24.

Enumeration of Total Coliforms, Fecal Coliforms, and Escherichia coli in Foods by Hydrophobic Grid Membrane Filter: Supplementary Report

1984 ◽  
Vol 67 (4) ◽  
pp. 811-812
Author(s):  
Phyllis Entis
Keyword(s):  
Escherichia Coli ◽  
Membrane Filter ◽  
Total Coliform ◽  
Fecal Coliforms ◽  
Poultry Meat ◽  
Filter Method ◽  
Total Coliforms ◽  
The Media ◽  
Aoac Method ◽  
Membrane Filter Method

Abstract Raw, comminuted poultry meat was used to determine the specificity of the media and incubation conditions used in the hydrophobic grid membrane filter method. Confirmation rates for target colonies were 100% for total coliforms, 98% for fecal coliforms, and 97-99% for Escherichia coli. The results of total coliform enumeration in 30 pasteurized milk samples by both the hydrophobic grid membrane filter method and AOAC method 46.013-46.016 are also reported.

Development and evaluation of methods to detect coliphages in large volumes of water

2004 ◽  
Vol 50 (1) ◽  
pp. 211-217 ◽  
Author(s):  
M.D. Sobsey ◽  
M.V. Yates ◽  
F-C. Hsu ◽  
G. Lovelace ◽  
D. Battigelli ◽  
...  
Keyword(s):  
Membrane Filter ◽  
Most Probable Number ◽  
Filter Method ◽  
Cellulose Ester ◽  
Enrichment Method ◽  
Probable Number ◽  
E Coli ◽  
Filter Methods ◽  
Water Volumes ◽  
Male Specific

New and improved methods have been developed to detect somatic and male-specific coliphages in large volumes of water by single agar layer (SAL), enrichment and membrane filter methods. Somatic coliphages were detected efficiently on E. coli hosts C and CN13, male-specific coliphages were detected more efficiently on E. coli Famp than on Salmonella typhimurium WG49 and both types of coliphages were detected simultaneously on E. coli C3000. For water volumes of up to 100 ml, the SAL method was efficient and reliable. For water volumes of <1 L and as many as 10 multiple 1 L volumes, the enrichment method was efficient in detecting very low numbers of coliphages. Membrane filter methods, in which coliphages were adsorbed to and eluted from filters, also were relatively efficient, but they were less efficient than SAL and enrichment methods and were considered to be more cumbersome. For filter adsorption-elution methods, coliphage recoveries were most efficient for cellulose ester filters, less efficient for electropositive 1MDS filters and least efficient for a direct membrane filter method. Overall, the enrichment method was preferred because of its ability to easily and rapidly detect low levels of coliphages in large sample volumes by either presence-absence or most probable number quantification.

Detection of Escherichia coli by the nutrient agar plus 4-methylumbelliferyl β-D-glucuronide (MUG) membrane filter method

1993 ◽  
Vol 39 (11) ◽  
pp. 1066-1070 ◽  
Author(s):  
Lois C. Shadix ◽  
Michele E. Dunnigan ◽  
Eugene W. Rice
Keyword(s):  
Escherichia Coli ◽  
Membrane Filtration ◽  
Membrane Filter ◽  
Nutrient Agar ◽  
Coliform Bacteria ◽  
Filter Method ◽  
Isolation Medium ◽  
Long Wavelength ◽  
E Coli ◽  
Membrane Filter Method

A two-step membrane filter procedure was evaluated to determine the ability to differentiate Escherichia coli from other coliform bacteria recovered from water. M-Endo LES agar incubated at 35 °C for 24 ± 2 h was used as the initial isolation medium. Membranes containing coliform colonies were transferred to nutrient agar plus 4-methylumbelliferyl β-D-glucuronide (MUG) and incubated for an additional 4 h at 35 °C. Escherichia coli colonies were distinguished by fluorescence when viewed under a long-wavelength ultraviolet light. A total of 119 MUG-positive colonies were isolated from 15 water sources, of which 115 (96.6%) were identified as E. coli. An examination of 182 pure culture environmental E. coli isolates revealed that 167 isolates (91.8%) exhibited fluorescence on the nutrient agar plus MUG medium. Survivors of E. coli cultures exposed to chlorination were also capable of producing a positive MUG reaction.Key words: membrane filtration, 4-methylumbelliferyl β-D-glucuronide (MUG), Escherichia coli, water.

Microbial Quality of Bagged Baby Spinach and Romaine Lettuce: Effects of Top versus Bottom Sampling

2012 ◽  
Vol 75 (1) ◽  
pp. 132-136 ◽  
Author(s):  
JULIE A. KASE ◽  
STACEY BORENSTEIN ◽  
ROBERT J. BLODGETT ◽  
PETER C. H. FENG
Keyword(s):  
Escherichia Coli ◽  
Total Coliform ◽  
Coliform Bacteria ◽  
Most Probable Number ◽  
Microbial Quality ◽  
Romaine Lettuce ◽  
Probable Number ◽  
E Coli ◽  
Bottom Sampling

Contamination with Escherichia coli O157:H7 and Salmonella have called into question the safety and microbial quality of bagged ready-to-eat leafy greens. This study expands on previous findings that these goods have high total bacteria counts (TBC) and coliform counts, variation in counts among different lots, that Escherichia coli is present, and disparities in counts when bags are top or bottom sampled. Nearly 100 bags of baby spinach and hearts of romaine lettuce from a single brand were subjected to both top and bottom sampling. Product was blended, and a portion serially diluted and plated to obtain TBC. Total coliform and E. coli levels were estimated by the most-probable-number (MPN) technique with ColiComplete discs. Top-sampled TBC from bags of baby spinach (48 bags, 13 different lots) ranged from 3.9 to 8.1 log CFU/g and bottom-sampled TBC ranged from 4.0 to 8.2 log CFU/g, with 52% of the bags (or 39% of the lots) producing TBC higher in bottom samples. For hearts of romaine (47 bags from 19 different lots), top-sampled bags had TBC ranging from 2.4 to 7.0 log, and bottom-sampled bags had TBC from 3.3 to 7.3 log, with 64% of the bags (or 63% of the lots) showing higher TBC in bottom samples. However, we are unable to reject the hypothesis that the top and bottom samples from either commodity contain the same TBC (P ≥ 0.08). No E. coli was detected and total coliform bacteria counts were, with few exceptions, ≥210 MPN/g, irrespective of TBC. In general, lots with the most number of days before the printed “use-by” date had lower TBC. However, the R2 values for either baby spinach (0.4085) or hearts of romaine (0.2946) suggest that age might not be a very good predictor of higher TBC. TBC varied widely between lots and even more so within same-lot samples, as indicated by the sum of squares results. This finding, along with higher TBC in bottom samples, suggests further consideration when a microbiological sampling scheme of bagged produce is designed.

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