scholarly journals VIDAS Salmonella (SLM) Assay Method EasySLM with ChromID Salmonella (SM2) Agar

2009 ◽  
Vol 92 (6) ◽  
pp. 1861-1864 ◽  
Author(s):  
Ronald Johnson ◽  
John Mills ◽  
Judith Coln-Reveles ◽  
Thomas Hammack
Keyword(s):  
Peanut Butter ◽  
Reference Method ◽  
Black Pepper ◽  
Assay Method ◽  
Most Probable Number ◽  
Chicken Breast ◽  
Probable Number ◽  
Pork Sausage ◽  
Selective Enrichment ◽  
Matrix Extension

Abstract A method modification study was conducted for the VIDAS Salmonella (SLM) assay (AOAC Performance Tested MethodSM 020901) using the EasySLM method to validate a matrix extension for peanut butter. The VIDAS EasySLM method is a simple enrichment procedure compared to traditional Salmonella methods, requiring only pre-enrichment and a single selective enrichment media, Salmonella Xpress 2 (SX2) broth. SX2 replaces the two selective broths in traditional methods and eliminates the M broth transfer, incubation, and subsequent pooling of M broths prior to VIDAS assay. The validation study was conducted under the AOAC Research Institute Emergency Response Validation program. VIDAS SLM was compared to the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) method for detection of S. enterica ser. Typhimurium in peanut butter. All peanut butter samples were prepared, blind-coded, and shipped to the method developers' laboratory by Q Laboratories. In addition, Q Laboratories performed most probable number and reference method analyses on peanut butter samples. The VIDAS EasySLM ChromID Salmonella (SM2) Agar was previously validated in the Performance Tested Methods program for the detection of Salmonella in roast beef, raw ground pork, turkey, pork sausage, raw chicken breast, dry pet food, whole milk, ice cream, bagged spinach, shrimp (raw, peeled), raw cod, spent irrigation water, pecans, peanut butter, dry pasta, cake mix, ground black pepper, nonfat dry milk, liquid eggs, cantaloupe, and orange juice. In the matrix extension study for peanut butter, the VIDAS EasySLM method was shown to be equivalent to the appropriate reference culture procedure using both buffered peptone water pre-enrichment and the FDA-BAM lactose pre-enrichment in the two-step enrichment method with SX2 media. The current study extends the validation to include peanut butter.

Relative Effectiveness of Selenite Cystine Broth, Tetrathionate Broth, and Rappaport-Vassiliadis Medium for the Recovery of Salmonella from Raw Flesh and Other Highly Contaminated Foods: Precollaborative Study

1995 ◽  
Vol 78 (2) ◽  
pp. 375-380 ◽  
Author(s):  
Geraldine A June ◽  
Patricia S Sherrod ◽  
Thomas S Hammack ◽  
R Miguel Amaguana ◽  
Wallace H Andrews
Keyword(s):  
Relative Effectiveness ◽  
Ground Beef ◽  
Most Probable Number ◽  
Salmonella Spp ◽  
Probable Number ◽  
Pork Sausage ◽  
Selective Enrichment

Abstract The effectiveness of selenite cystine (SC) broth, tetrathionate (TT) broth, and Rappaport-Vassiliadis (RV) medium for recovery of Salmonella spp. from 8 highly contaminated foods was determined. RV medium prepared from individual ingredients and incubated at 42° and 43°C was compared with 2 commercial (Difco and Oxoid) media incubated at 42°C. Naturally and artificially contaminated foods were tested under 2 protocols. For Protocol 1, each food was preenriched in the appropriate medium. After incubation, serial 10 fold dilutions of the preenriched foods were inoculated into selective enrichment media and incubated at 35°, 42°, or 43°C. Effectiveness of these conditions was evaluated by most probable number determination of Salmonella spp. recovered. Productivity of selective enrichments did not differ significantly with this protocol, except that with Oxoid RV medium the number of Salmonella cells recovered from most of the foods was significantly reduced. For Protocol 2, twenty 25 g test portions from artificially inoculated foods were examined qualitatively for Salmonella spp. The effectiveness of the broth/temperature combinations was determined by the number of positive tests under each condition. RV medium prepared from individual ingredients and TT broth incubated at 43°C yielded significantly more Salmonella-positive tests from frog legs and lettuce than did SC and TT broths incubated at 35°C or commercial RV medium incubated at 42°C. With pork sausage and ground beef, significantly fewer Salmonella-positive tests were found with Oxoid RV medium incubated at 42°C and SC incubated at 35°C than from other selective enrichments. With chicken, fewer Salmonella-positive tests were found from SC and TT broths incubated at 35°C and Oxoid RV medium incubated at 42°C than from other selective enrichments. There were no significant differences among selective enrichments in the recovery of Salmonella spp. from the remaining foods. Overall, RV prepared from individual ingredients and incubated at 42°C yielded the highest number of Salmonella-posWive tests.

scholarly journals foodproof Salmonella Detection Kit

2009 ◽  
Vol 92 (6) ◽  
pp. 1876-1884 ◽  
Author(s):  
Charlotte Lindhardt ◽  
Holger Schönenbrücher ◽  
Jörg Slaghuis ◽  
Andreas Bubert ◽  
Rolf Ossmer ◽  
...  
Keyword(s):  
Peanut Butter ◽  
Reference Method ◽  
Extension Study ◽  
Most Probable Number ◽  
Performance Difference ◽  
Pet Food ◽  
Chi Square ◽  
Probable Number ◽  
Significant Performance ◽  
The U.S

Abstract The foodproof Salmonella Detection Kit was previously validated in the Performance Tested MethodsSM program for the detection of Salmonella species in a variety of foods, including milk powder, egg powder, coconut, cocoa powder, chicken breast, minced meat, sliced sausage, sausage, smoked fish, pasta, white pepper, cumin, dough, wet pet food, dry pet food, ice cream, watermelon, sliced cabbage, food dye, and milk chocolate. The method was shown to be equivalent to the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) and the U.S. Department of Agriculture, Food Safety and Inspection Service's Microbiology Laboratory Guidebook reference culture procedures. In the first Emergency Response Validation (ERV) extension study, peanut butter was inoculated with S. enterica. ser Typhimurium. For the low inoculation level (1.08 CFU/25 g), a Chi-square value of 2.25 indicated that there was no significant performance difference between the foodproof Salmonella Detection Kit and the FDA-BAM reference method. For high-level inoculation (11.5 CFU/25 g) and uninoculated control, there was 100 agreement between the methods. In the second ERV extension study, peanut butter was inoculated with S. enterica. ser Typhimurium. For both inoculation levels (0.1 and 0.5 CFU/25 g by most probable number), Chi-square values of 0 indicated that there was no significant performance difference between foodproof Salmonella Detection Kit and the FDA-BAM reference method.

InstantLabs®Salmonella Species Detection Method: Matrix Extension

2014 ◽  
Vol 97 (6) ◽  
pp. 1585-1591
Author(s):  
Neil Sharma ◽  
Lauren Bambusch ◽  
Thu Le ◽  
Amit Morey ◽  
Melinda Hayman ◽  
...  
Keyword(s):  
Ground Beef ◽  
Reference Method ◽  
Test Method ◽  
Chicken Breast ◽  
Escherichia Coli O157 ◽  
Test Portion ◽  
Screen Result ◽  
Low Levels ◽  
Matrix Extension ◽  
Better Than

Abstract The performance of InstantLabs®Salmonella Species Food Safety Kit to detect Salmonella in four food matrixes was validated against the International Organization for Standardization (ISO) reference method 6579:2002. The matrixes (raw ground beef, raw chicken breast, raw ground chicken, and lettuce) were inoculated with low levels of Salmonella (<1 CFU/test portion) to generate fractional positives (5–15) in 20 inoculated samples. These matrixes were co-inoculated with Escherichia coli O157:H7 at two to five times the level of Salmonella. Samples were validated using 375 g (meat) or 25 g (lettuce and poultry) test portions enriched in FASTGRO™ SE at 42 ± 1°C for 12 h and 10 h, respectively. All samples were confirmed using the ISO reference method, regardless of initial screen result. The InstantLabs test method was shown to perform as well as or better than the reference method for the detection of Salmonella species in ground beef, chicken breast, ground chicken, and lettuce. Inclusivity and exclusivity testing revealed no false negatives among the 100 Salmonella serovars and no false positives among the 30 non-Salmonella species examined, respectively.

Culturable Populations of Sporomusa spp. and Desulfovibrio spp. in the Anoxic Bulk Soil of Flooded Rice Microcosms

1999 ◽  
Vol 65 (8) ◽  
pp. 3526-3533 ◽  
Author(s):  
Dirk Rosencrantz ◽  
Frederick A. Rainey ◽  
Peter H. Janssen
Keyword(s):  
Ethylene Glycol ◽  
Bulk Soil ◽  
Most Probable Number ◽  
Culturable Bacteria ◽  
Soil System ◽  
Probable Number ◽  
Selective Enrichment ◽  
Methanospirillum Hungatei ◽  
Dry Soil ◽  
Different Strains

ABSTRACT Most-probable-number (MPN) counts were made of homoacetogenic and other bacteria present in the anoxic flooded bulk soil of laboratory microcosms containing 90- to 95-day-old rice plants. MPN counts with substrates known to be useful for the selective enrichment or the cultivation of homoacetogenic bacteria (betaine, ethylene glycol, 2,3-butanediol, and 3,4,5-trimethoxybenzoate) gave counts of 2.3 × 103 to 2.8 × 105 cells per g of dry soil. Homoacetogens isolated from the terminal positive steps of these dilution cultures belonged to the genus Sporomusa. Counts with succinate, ethanol, and lactate gave much higher MPNs of 5.9 × 105 to 3.4 × 107 cells per g of dry soil and led to the isolation of Desulfovibrio spp. Counting experiments on lactate and ethanol which includedMethanospirillum hungatei in the medium gave MPNs of 2.3 × 106 to 7.5 × 108 cells per g of dry soil and led to the isolation of Sporomusa spp. The latter strains could grow with betaine, ethylene glycol, 2,3-butanediol, and/or 3,4,5-trimethoxybenzoate, but apparently most cells of Sporomusa spp. did not initiate growth in counting experiments with those substrates. Spores apparently accounted for 2.2% or less of the culturable bacteria. It appears that culturableDesulfovibrio spp. and Sporomusa spp. were present in approximately equal numbers in the bulk soil. Multiple, phylogenetically-distinct, phenotypically-different, strains of each genus were found in the same soil system.

scholarly journals Modification and Matrix Extension of the Bio-Rad iQ-Check E. coli O157:H7, STEC VirX, and STEC SerO Test Kits for the Detection of Shiga Toxin–Producing Escherichia coli (STEC) and Escherichia coli O157 From a Single Enrichment

2020 ◽  
Vol 103 (1) ◽  
pp. 161-175
Author(s):  
Dane Brooks ◽  
Benjamin Bastin ◽  
Erin Crowley ◽  
James Agin ◽  
Mike Clark ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Real Time ◽  
Real Time Pcr ◽  
Ground Beef ◽  
Reference Method ◽  
Chicken Breast ◽  
E Coli ◽  
Free Dna ◽  
Target Analytes ◽  
Matrix Extension

Abstract Background: The iQ-Check Real-Time PCR kits use PCR technology based on gene amplification and detection by a real-time PCR thermalcycler for the detection of target analytes in select food matrices. The iQ-Check E. coli O157:H7 [Performance Tested MethodSM (PTM) 020801] and STEC VirX and STEC SerO (combined PTM 121203) methods were previously validated for different matrices under different enrichment schemes. Objective: To modify the current iQ-Check E. coli O157:H7 Kit for the detection of Escherichia coli O157:H7 from 25 to 375 g for raw ground beef (17% fat), raw beef trim, and fresh spinach. In addition, a matrix extension was validated for iQ-Check E. coli O157:H7 for raw chicken breast without skin (25 g), raw chicken thigh with skin (25 g), mechanically separated chicken (25 g), and raw ground pork (25 g). The study also included the modification of the iQ-Check STEC VirX and SerO Kits for the detection of non-O157 Shiga toxin–producing E. coli (STEC) for raw ground beef (375 g), raw beef trim (375 g), and fresh spinach (375 g) from STEC Enrichment Broth to buffered peptone water (BPW). All tests were carried out at 8–22 h (10–22 h for fresh spinach). Methods: Ground beef, beef trim, and spinach were co-inoculated with E. coli O157:H7, non-O157 STECs, and Salmonella spp. and analyzed for E. coli O157:H7 and non-O157 STECs after an 8-22 h enrichment in BPW for the beef matrices and after a 10–22 h enrichment in BPW for spinach. The chicken matrices were inoculated with E. coli O157:H7 only and analyzed after an 8–22 h enrichment in BPW. The iQ-Check Free DNA Removal Solution workflow was utilized for all matrices. Confirmations at the 22 h time point and method comparisons were conducted with the appropriate reference method as outlined in the U.S. Food and Drug Administration Bacteriological Analytical Manual Chapter 4A or the U.S. Department of Agriculture Food Safety and Inspection Service Microbiology Laboratory Guidebook Chapters 5.09 and 5B.05. For the iQ-Check STEC VirX and STEC SerO Kits, inclusivity and exclusivity were also performed. Results: The two inclusivity and exclusivity evaluations indicated that the test methods can accurately detect the target analytes and correctly excluded nontarget organisms after 8 h of enrichment. In the method comparison study, the iQ-Check E. coli O157:H7 and STEC VirX and STEC SerO test kits demonstrated no statistically significant differences between candidate and reference method results or between presumptive and confirmed results for all food matrices analyzed and the two time points (8 or 10 and 22 h). Both time points produced the same results, with no discrepancies. Conclusions: The iQ-Check real-time PCR kits are effective methods for the detection of E. coli O157 and non-O157 STECs (both the virulence factors and the O groups) from raw ground beef, raw beef trim, and fresh spinach in 375 g samples enriched in BPW for 8–22 h (10–22 h for fresh spinach). In addition, the iQ-Check E. coli O157 Kit is effective in detecting E. coli O157 in 25 g samples of raw chicken breast without skin, raw chicken thigh with skin, mechanically separated chicken, and raw ground pork. The iQ-Check test kits allow the end user to pair enrichments for multiple target analytes, allowing the user to prepare a single enrichment and perform a single DNA extraction. The Free DNA Removal Solution removes free DNA from samples prior to PCR analysis, protecting DNA from intact and living cells. Highlights: The method modifications were granted based on the data collected.

scholarly journals Evaluation of Applied Biosystems MicroSEQ® Real-Time PCR System for Detection of Salmonella spp. in Food

2011 ◽  
Vol 94 (4) ◽  
pp. 1106-1116 ◽  
Author(s):  
Priya Balachandran ◽  
Yanxiang Cao ◽  
Lily Wong ◽  
Manohar R Furtado ◽  
Olga V Petrauskene ◽  
...  
Keyword(s):  
Real Time ◽  
Study Design ◽  
Real Time Pcr ◽  
Detection System ◽  
Peanut Butter ◽  
Reference Method ◽  
Black Pepper ◽  
Salmonella Spp ◽  
Culture Methods ◽  
Significant Difference

Abstract Real-time PCR methods for detecting foodborne pathogens offer the advantages of simplicity and quick time-to-results compared to traditional culture methods. In this study, the MicroSEQ® real-time PCR system was evaluated for detection of Salmonella spp. in 10 different food matrixes following the AOAC Research Institute's Performance Tested MethodSM validation program. In addition, the performance of the MicroSEQ system was evaluated for the detection of Salmonella in peanut butter as a part of the Emergency Response Validation Program sponsored by the AOAC Research Institute. The system was compared to the ISO 6579 reference method using a paired-study design for detecting Salmonella spp. in raw ground beef, raw chicken, raw shrimp, Brie cheese, shell eggs, cantaloupe, chocolate, black pepper, dry infant formula, and dry pet food. For the peanut butter study, the system was compared to the U.S. Food and Drug Administration's Bacteriological Analytical Manual procedures using an unpaired-study design. No significant difference in performance was observed between the MicroSEQ Salmonella spp. detection system and the corresponding reference methods for all 11 food matrixes. The MicroSEQ system detected all Salmonella strains tested, while showing good discrimination against detection of an exclusivity panel of 30 strains, with high accuracy.

scholarly journals Defined and undefined commercial probiotics cultures in the prevention of Salmonella Enteritidis in broilers

2018 ◽  
Vol 38 (2) ◽  
pp. 271-276
Author(s):  
Erich H. Carvalho ◽  
Angélica S. Mendes ◽  
Sabrina E. Takahashi ◽  
Rosângela A.B. Assumpção ◽  
Douglas V. Bonamigo ◽  
...  
Keyword(s):  
Salmonella Enteritidis ◽  
Culture Liquid ◽  
Most Probable Number ◽  
Microbiological Analysis ◽  
Feed Conversion ◽  
Liquid Form ◽  
Probable Number ◽  
Selective Enrichment ◽  
Enrichment Technique ◽  
Defined Culture

ABSTRACT: This study aimed to evaluate the efficacy of probiotics from different formations, defined and undefined cultures, applied in the control of Salmonella Enteritidis in broilers, identifying the compositions and states for which the probiotics are more effective. For that, 390 broilers were inoculated orally with 1.00 ml of Salmonella Enteritidis at a concentration of 1.2x109 CFU (Colony Forming Units). The experimental design used was randomized blocks with 5 treatments and 6 replications, totaling 30 boxes with 13 birds/box (13 birds/m2). The treatments were provided via drinking water 1 hour after inoculation, keeping a daily treatment of 12 hours with probiotics, for 3 consecutive days (birds at 1, 2 and 3 days of age). In general, the five treatments conducted were: T1 - Control without probiotic, T2 - Probiotic A (defined culture - lyophilized form, strain 7), T3 - Probiotic B (defined culture - lyophilized form, strain 11), T4 - Probiotic C (undefined culture liquid form), T5 - Probiotic D (undefined culture - liquid form). After treatments, performance was evaluated through average body weight, feed conversion and mortality counting. Microbiological analysis and Salmonella isolation were performed using MPN (Most Probable Number) and selective enrichment technique methods, respectively. Samples of ileum and liver pool, cecal tonsils, cecum, heart and spleen pool were collected at 5 and 31 days of age. No differences were observed on growth performance and isolation of Salmonella Enteritidis (p≥0.05). All probiotics applied were effective on reducing Salmonella Enteritidis colonization in the ileum, cecal tonsils, and cecum at 5 days of life. Probiotics T2 and T5 has shown effectiveness in reducing colonization at 31 days, being considered the most efficient on Salmonella Enteritidis control, for the intestines segments evaluated. It was not possible to affirm which probiotics formation, defined or undefined, is more efficient for Salmonella Enteritidis control.

Microbial Evaluation of Spanish Potato Omelette and Cooked Meat Samples in University Restaurants

2000 ◽  
Vol 63 (9) ◽  
pp. 1273-1276 ◽  
Author(s):  
J. M. SORIANO ◽  
H. RICO ◽  
J. C. MOLTÓ ◽  
J. MAÑES
Keyword(s):  
Control Point ◽  
Most Probable Number ◽  
Probable Number ◽  
Pork Sausage ◽  
E Coli ◽  
Meat Samples ◽  
Cooked Meat ◽  
Group D ◽  
Coagulase Positive Staphylococci ◽  
Lancefield Group

The focus of this study was to evaluate the microbial quality of Spanish potato omelette and cooked meat samples including pork loin, chicken croquettes, long pork sausage, chicken breast, and meatballs from University restaurants. Microbiological analyses of Spanish potato omelette and cooked meat samples resulted in aerobic plate counts from <1.00 to 2.90 and from <1.00 to 6.04 log10 CFU g−1, respectively. Total coliforms ranged from <3 to 43 most probable number (MPN) g−1 and from <3 to >2,400 MPN g−1 for Spanish potato omelette and meat products, respectively. Escherichia coli, coagulase-positive staphylococci, and Lancefield group-D streptococci were detected in 1.7%, 3.5%, and 12.9% of Spanish potato omelette samples, respectively. For cooked meat samples, 8.8%, 7.6%, and 24.6% contained E. coli, coagulase-positive staphylococci, and Lancefield group-D streptococci, respectively. E. coli O157:H7, Salmonella spp., and Shigella spp. were not detected. Klebsiella pneumoniae, Klebsiella oxytoca, Citrobacter freundii, Enterobacter cloacae, and Serratia spp. were isolated from Spanish potato omelette samples. For cooked meat samples, C. freundii, E. cloacae, and Aeromonas hydrophila were detected. The results suggest that some handling practices should require more attention, and as a consequence, a hazard analysis and critical control point program should be developed and implemented.

Salmonella Levels in Turkey Neck Skins, Drumstick Bones, and Spleens in Relation to Ground Turkey

2015 ◽  
Vol 78 (11) ◽  
pp. 1945-1953 ◽  
Author(s):  
YUE CUI ◽  
HUSNU S. GURAN ◽  
MARK A. HARRISON ◽  
CHARLES L. HOFACRE ◽  
WALID Q. ALALI
Keyword(s):  
Pulsed Field Gel Electrophoresis ◽  
Most Probable Number ◽  
Processing Plant ◽  
Probable Number ◽  
Selective Enrichment ◽  
Genotypic Analysis ◽  
Low Levels ◽  
Contamination Levels ◽  
Commercial Turkey ◽  
Skin Samples

The objective of this study was to determine Salmonella levels (presence and numbers) in turkey drumstick bone, spleen, and neck skin samples in relation to Salmonella contamination levels in ground turkey at the flock level. Over a 10-month period, a total of 300 samples of each turkey part (i.e., neck skin, spleen, and drumstick) from 20 flocks were collected at a commercial turkey processing plant after the evisceration step. Turkey flocks included in this study were classified as “targeted” and “nontargeted” based on the company's historical ground turkey contamination data. A flock that originated from a turkey farm that had previously produced one or more flocks with ≥20% Salmonella prevalence in ground turkey was labeled as a targeted flock (n=13). The remaining seven flocks with <20% prevalence were labeled as nontargeted. All samples collected were tested for Salmonella presence and numbers by using most-probable-number and selective enrichment methods. Further genotypic analysis (pulsed-field gel electrophoresis) of the isolates was performed. Ground turkey samples were collected and analyzed for Salmonella levels by the cooperating turkey company. The outside surface of bone and spleen were sterilized prior to Salmonella analysis. The overall Salmonella prevalence in neck skin, drumstick bone, spleen, and ground turkey samples was 42.0, 9.3, 6.7, and 14.5%, respectively. Salmonella prevalence in neck skin, spleen, drumstick bone, and ground turkey from the targeted flocks was significantly (P < 0.05) higher than those from nontargeted flocks. There was a significant relationship between Salmonella presence in neck skin (when most probable numbers were ≥2 log) and Salmonella-positive ground turkey lot. Based on our findings, Salmonella was detected internally in drumstick bones and spleens at low levels, whereas Salmonella presence at higher levels in neck skin may indicate a flock with greater potential for Salmonella contamination of ground turkey.

scholarly journals GeneQuence Salmonella Assay

2009 ◽  
Vol 92 (6) ◽  
pp. 1840-1845 ◽  
Author(s):  
Susan Alles ◽  
Mark Mozola ◽  
Thomas Hammack
Keyword(s):  
Sensitivity And Specificity ◽  
Peanut Butter ◽  
Most Probable Number ◽  
Probable Number ◽  
Low Level ◽  
Reference Methods ◽  
Two Samples ◽  
High Level ◽  
Positive Results ◽  
Control Samples

Abstract A study was conducted to validate the GeneQuence Salmonella DNA hybridization assay, Performance Tested Method 030201, for detection of Salmonella spp. in peanut butter. The study was organized by the AOAC Research Institute under its Emergency Response Validation program. Peanut butter samples inoculated with S. Typhimurium were prepared by an independent laboratory and shipped to study participants for testing. The set of blind-coded test samples consisted of five uninoculated controls, 20 portions inoculated with S. Typhimurium at a low level [determined by most probable number (MPN) analysis to contain 1.1 CFU/25 g portion], and 20 portions inoculated with S. Typhimurium at a higher level (11 CFU/25 g portion by MPN analysis). Samples were tested in parallel by the GeneQuence method and by the U.S. Food and Drug Administration's Bacteriological Analytical Manual reference culture procedure. All five control samples were negative by both methods. For the low-level samples, the same two samples were positive by both the GeneQuence and reference methods. For the high-level samples, the same 19 samples were positive by both methods. All positive GeneQuence assays were confirmed by plating from associated broth cultures. Agreement between the GeneQuence and reference methods was 100. Sensitivity and specificity of the GeneQuence method were both 100. Because neither the low- nor the high-level samples yielded the desired fractional positive results (515 positives out of 20 samples), a second trial was conducted. Samples in the second trial contained 0.1 and 0.5 CFU/25 g portion for the low and high levels, respectively. All five control samples were negative by both methods. For the low-level samples, the same two samples were positive by both the GeneQuence and reference methods. For the high-level samples, the same three samples were positive by both methods. All positive GeneQuence assays were confirmed by plating from associated broth cultures. Sensitivity and specificity of the GeneQuence method were both 100. Although once again the desired level of fractional positive results was not obtained, there was 100 agreement between the GeneQuence and reference methods. Based on the results of both trials, it is recommended that the validated claims for Performance Tested Method 030201 be expanded to include peanut butter.

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