scholarly journals Two-Day Hydrophobic Grid Membrane Filter Method for Yeast and Mold Enumeration in Foods Using YM-11 Agar: Collaborative Study

1996 ◽  
Vol 79 (5) ◽  
pp. 1069-1082 ◽  
Author(s):  
Phyllis Entis ◽  
A Athar ◽  
M Ballenger ◽  
M S Bendeck ◽  
W Birbari ◽  
...  
Keyword(s):  
Orange Juice ◽  
Membrane Filter ◽  
Collaborative Study ◽  
Ground Beef ◽  
Reference Method ◽  
Test Method ◽  
Filter Method ◽  
Garlic Powder ◽  
Reference Methods ◽  
Membrane Filter Method

Abstract Twenty laboratories participated in a collaborative study to validate a 2-day hydrophobic grid membrane filter method using YM-11 agar for enumeration of yeast and mold in foods. Six naturally contaminated food products were included in the study: garlic powder, raw ground beef, walnuts, flour/meal, orange juice, and yogurt. The test method produced significantly higher results than the 5-day pour plate reference method for orange juice and significantly lower, though numerically similar, results for walnuts and yogurt. Differences between the test and reference methods were not significant for garlic powder, raw ground beef, or flour/meal. Repeatability and reproducibility were similar for both the test and reference methods in all cases. The hydrophobic grid membrane filter method for enumeration of yeast and mold in foods has been adopted by AOAC INTERNATIONAL.

Enumeration of β-Glucuronidase-Positive Escherichia coli in Foods by Using the ISO-GRID Method with SD-39 Agar

1998 ◽  
Vol 61 (7) ◽  
pp. 913-916 ◽  
Author(s):  
PHYLLIS ENTIS ◽  
IRINA LERNER
Keyword(s):  
Escherichia Coli ◽  
Membrane Filter ◽  
Reference Method ◽  
Grid Method ◽  
Test Method ◽  
Cottage Cheese ◽  
Filter Method ◽  
Official Method ◽  
Membrane Filter Method ◽  
Aoac Official

A study was undertaken to compare β-glucuronidase-positive Escherichia coli counts produced by the ISO-GRID hydrophobic grid membrane filter method using SD-39 agar (test method) with those produced by AOAC Official Method 990.11, an existing ISO-GRID method using lactose monensin glucuronate agar and buffered MUG agar (reference method). The methods were evaluated using 21 food products, with three independent lots of five replicate samples analyzed per product by both methods. The test and reference methods were statistically equivalent for 19 of the 21 products; frozen, raw ground lamb produced significantly higher counts using the reference method, whereas counts obtained from cottage cheese were significantly higher using the SD-39 agar-based method.

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

1984 ◽  
Vol 67 (4) ◽  
pp. 812-823
Author(s):  
Phyllis Entis ◽  
◽  
B Bennett ◽  
M H Brodsky ◽  
D M Burgener ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Filter ◽  
Collaborative Study ◽  
Reference Method ◽  
Black Pepper ◽  
Fecal Coliforms ◽  
Filter Method ◽  
Total Coliforms ◽  
E Coli ◽  
Membrane Filter Method

Abstract A collaborative study was conducted in 18 laboratories to assess the performance of the hydrophobic grid membrane filter method against that of the AOAC official first action method 46.013-46.016 for enumerating total and fecal coliforms and Escherichia coli. The study was carried out on frozen breaded fish, raw comminuted poultry, unroasted walnut pieces, ground black pepper, and cheddar cheese. The hydrophobic grid membrane filter method recovered significantly larger numbers of target bacteria in 7 of the food/analysis combinations: fecal coliforms in fish; E. coli in poultry; fecal coliforms and E. coli in walnuts; and total coliforms, fecal coliforms and E. coli in black pepper. Random error (Sr2) associated with the hydrophobic grid membrane filter method was significantly lower than that of the reference method in over 30% of the paired sample series. The hydrophobic grid membrane filter method for total coliform, fecal coliform, and E. coli enumeration in foods has been adopted official first action.

Enumeration of Coliforms in Nonfat Dry Milk and Canned Custard by Hydrophobic Grid Membrane Filter Method: Collaborative Study

1983 ◽  
Vol 66 (4) ◽  
pp. 897-904
Author(s):  
Phyllis Entis ◽  
◽  
B W Ciebin ◽  
V Gipson ◽  
M Grahn ◽  
...  
Keyword(s):  
Membrane Filter ◽  
Collaborative Study ◽  
Reference Method ◽  
New Method ◽  
Filter Method ◽  
Official Method ◽  
Random Errors ◽  
Dry Milk ◽  
Membrane Filter Method ◽  
Nonfat Dry Milk

Abstract A collaborative study was conducted in 14 laboratories to evaluate the performance of the hydrophobic grid membrane filter method against the official final action method, 46.016, for enumeration of colif orms in foods. Twelve artificially contaminated samples of nonfat dry milk and canned custard were analyzed by each laboratory. The random errors (Sr2) associated with the hydrophobic grid membrane filter method were significantly lower than those of the official method, and the counts obtained by the new method fell within the 95% confidence interval of the reference method. The colif orm counts obtained by tiie hydrophobic grid membrane filter method did not differ significantly from those obtained by the reference method as measured by a 3-way analysis of variance. The new method has been adopted official first action.

Rapid Hydrophobic Grid Membrane Filter Method for Salmonella Detection in Selected Foods: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 555-564
Author(s):  
Phyllis Entis
Keyword(s):  
Membrane Filter ◽  
Collaborative Study ◽  
Reference Method ◽  
Black Pepper ◽  
Poultry Meat ◽  
Filter Method ◽  
Dry Milk ◽  
Membrane Filter Method ◽  
Nonfat Dry Milk ◽  
Egg Powder

Abstract A collaborative study was carried out in 36 laboratories to validate a hydrophobic grid membrane filter method for rapid (2-3 days) Salmonella detection by comparing its performance against the AOAC/ BAM reference method. Six products were included in the study: semisweet chocolate, raw ground poultry meat, ground black pepper, cheese powder, egg powder, and nonfat dry milk. With the exception of the naturally contaminated poultry, all products were inoculated in advance with low concentrations of a variety of Salmonella serotypes. The hydrophobic grid membrane filter method detected the following numbers of positive samples (results of the AOAC/BAM reference method are shown in parentheses): chocolate, 67(68); raw ground poultry, 133(131); ground black pepper, 57(56); cheese powder, 81(80); egg powder, 51(45); and nonfat dry milk, 68(72). The 2 methods did not differ significantly at the 95% confidence level in any of the 6 foods. The hydrophobic grid membrane filter method has been adopted official first action for detection of Salmonella in selected foods.

scholarly journals Direct 24-Hour Presumptive Enumeration of Escherichia coli 0157:H7 in Foods Using Hydrophobic Grid Membrane Filter Followed by Serological Confirmation: Collaborative Study

1998 ◽  
Vol 81 (2) ◽  
pp. 403-418 ◽  
Author(s):  
Phyllis Entis ◽  
◽  
D Bryant ◽  
J Bryant ◽  
R G Bryant ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Filter ◽  
Collaborative Study ◽  
Reference Method ◽  
Test Method ◽  
Cottage Cheese ◽  
Apple Cider ◽  
Dairy Foods ◽  
E Coli ◽  
Repeatability And Reproducibility

abstract Fifteen laboratories took part in a collaborative study to validate a method for enumerating Escherichia coli 0157:H7. The method is based on use of a hydrophobic grid membrane filter and consists of 24 h presumptive enumeration on SD-39 Agar and serological confirmation to yield a confirmed E. coli 0157:H7 count. Six food products were analyzed: pasteurized apple cider, pasteurized 2% milk, cottage cheese, cooked ground pork, raw ground beef, and frozen whole egg. The test method produced significantly higher confirmed count results than did the reference method for milk, pork, and beef. Test method results were numerically higher than but statistically equivalent to reference method results for cheese, cider, and egg. The test method produced lower repeatability and reproducibility values than did the reference method for most food/inoculation level combinations and values very similar to those of the reference method for the remaining combinations. Overall, 94% of presumptive positive isolates from the test method were confirmed serologically as E. coli 0157:H7, and 98% of these were also biochemically typical of E. coli 0157:H7 (completed test). Corresponding rates for the reference method were 69 and 98%, respectively. On the basis of the results of this collaborative study and the precollaborative study that preceded it, it is recommended that this method be adopted official first action for enumeration of E. coli 0157:H7 in meats, poultry, dairy foods, infant formula, liquid eggs, mayonnaise, and apple cider

Hydrophobic Grid Membrane Filter Method for Aerobic Plate Count in Foods: Collaborative Study

1986 ◽  
Vol 69 (4) ◽  
pp. 671-676 ◽  
Author(s):  
Phyllis Entis ◽  
◽  
J Allen ◽  
A Bhatnagar ◽  
A Brouwer ◽  
...  
Keyword(s):  
Membrane Filter ◽  
Collaborative Study ◽  
Raw Milk ◽  
Plate Count ◽  
Filter Method ◽  
Membrane Filter Method ◽  
Aerobic Plate Count ◽  
Egg Powder ◽  
Raw Poultry ◽  
Whole Egg

Abstract Twenty-one laboratories participated in a collaborative study to validate a hydrophobic grid membrane filter (HGMF) method for aerobic plate count by comparing its performance against the AOAC/APHA pour plate method. Raw milk, raw poultry, whole egg powder, flours, and spices were included in the study. Counts obtained by the HGMF and pour plate methods did not differ significantly, except in the case of whole egg powder, for which the HGMF method produced significantly higher counts. The hydrophobic grid membrane filter method for aerobic plate count in foods has been adopted official first action.

Detection of Salmonella species in a Variety of Foods by the DuPont™ BAX® System Real-Time PCR Assay for Salmonella: First Action 2013.02

2014 ◽  
Vol 97 (3) ◽  
pp. 868-875 ◽  
Author(s):  
F Morgan Wallace ◽  
Bridget Andaloro ◽  
Dawn Fallon ◽  
Nisha Corrigan ◽  
Stephen Varkey ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Orange Juice ◽  
Collaborative Study ◽  
Reference Method ◽  
Probability Of Detection ◽  
Test Method ◽  
Pcr Assay ◽  
Test Portion ◽  
Significant Difference

Abstract A multilaboratory study was conducted to evaluate the ability of the DuPont™ BAX® System Real-Time PCR Assay for Salmonella to detect the target species in a variety of foods and environmental surfaces. Internal validation studies were performed by DuPont Nutrition & Health on 24 different sample types to demonstrate the reliability of the test method among a wide variety of sample types. Two of these matrixes—pork and turkey frankfurters and pasteurized, not-from-concentrate orange juice without pulp—were each evaluated in 14 independent laboratories as part of the collaborative study to demonstrate repeatability and reproducibility of the internal laboratory results independent of the end user. Frankfurter samples were evaluated against the U. S. Department of Agriculture, Food Safety and Inspection Service reference method as a paired study, while orange juice samples were evaluated against the U. S. Food and Drug Administration reference method as an unpaired study, using a proprietary media for the test method. Samples tested in this study were artificially inoculated with a Salmonella strain at levels expected to produce low (0.2–2.0 CFU/test portion) or high (5 CFU/test portion) spike levels on the day of analysis. For each matrix, the collaborative study failed to show a statistically significant difference between the candidate method and the reference method using the probability of detection statistical model.

scholarly journals Evaluation of the Assurance GDS™ for E. coli O157:H7 Method and Assurance GDS for Shigatoxin Genes Method in Selected Foods: Collaborative Study

2005 ◽  
Vol 88 (5) ◽  
pp. 1334-1348 ◽  
Author(s):  
Philip T Feldsine ◽  
Shannon T Green ◽  
Andrew H Lienau ◽  
James Stephens ◽  
Markus T Jucker ◽  
...  
Keyword(s):  
Orange Juice ◽  
Collaborative Study ◽  
Ground Beef ◽  
Culture Methods ◽  
Chi Square ◽  
E Coli ◽  
Reference Methods ◽  
Uninoculated Control ◽  
Chi Square Analysis ◽  
Better Than

Abstract A multilaboratory collaborative study was conducted to compare the Assurance GDS™ for E. coli O157:H7 method and the reference culture methods for the detection of E. coli O157:H7 in orange juice, raw ground beef, and fresh lettuce. A separate companion assay, the Assurance GDS for Shigatoxin Genes method was also evaluated with the same test portions. Fifteen laboratories participated in the study. A Chi square analysis of each of the 3 food types at the high, low, and uninoculated control levels was performed. For all foods, the Assurance GDS for E. coli O157:H7 method and the Assurance GDS for Shigatoxin Genes method were equivalent to or better than the reference methods.

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.

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