Immunomagnetic Separation and Visual Fluorescence Detection of Salmonella spp., Using AOAC Approved SASTM Molecular Tests

2014 ◽  
Vol 97 (4) ◽  
pp. 1067-1072
Author(s):  
Chandra Bapanpally ◽  
Gayatri Maganty ◽  
Shah Khan ◽  
Akif Kasra ◽  
Amit Morey
Keyword(s):  
Reference Method ◽  
Current Method ◽  
Immunomagnetic Separation ◽  
Salmonella Spp ◽  
Test Portion ◽  
Molecular Tests ◽  
Modified Method ◽  
Reference Methods ◽  
Chicken Carcass ◽  
The U.S

Abstract The SASTM Molecular Tests method for detection of Salmonella spp. in various food matrixes has been certified by the AOAC Research Institute and designated Performance Tested MethodSM No. 021202. The current method modification includes the optional immunomagnetic separation (IMS) to enrich the bacteria as well as optional visual fluorescence readout without the use of a turbidimeter. The modifications were validated against the U.S. Department of Agriculture/Food Safety and Inspection Service Microbiology Laboratory Guidebook (MLG) and the U.S. Food and Drug Administration Bacteriological Analytical Manual (BAM) reference methods. Food matrixes (chicken carcass rinse, beef trim, and spinach) were inoculated with low levels of Salmonella spp. (0.2–2 CFU/test portion) to generate fractional positives (5–15) in 20 inoculated samples. Samples were enriched with SAS Enrichment medium and incubated at 42 ± 1°C. Enrichments were tested directly and subjected to anti-Salmonella IMS prior to the SAS Molecular Tests. Results were determined via visual fluorescence and via turbidity using a turbidimeter. All replicates were confirmed using the MLG or BAM reference method procedures, regardless of presumptive result. The SAS Molecular Tests Salmonella Detection modified methods were determined to be equivalent to the reference methods for the detection of Salmonella in chicken carcass rinse, beef trim, and fresh spinach. The inclusion of IMS in the modified method improved the detection rate of Salmonella in chicken carcass rinses and spinach. The optional use of visual fluorescent reagent and heat block either with IMS or without IMS produced results that were comparable to the results obtained from using a real-time turbidimeter.

Immunomagnetic Separation and Visual Fluorescence Detection of E. coli O157 Using AOAC Approved SASTM Molecular Tests

2014 ◽  
Vol 97 (4) ◽  
pp. 1073-1077
Author(s):  
Chandra Bapanpally ◽  
Gayatri Maganty ◽  
Shah Khan ◽  
Akif Kasra ◽  
Amit Morey
Keyword(s):  
Detection Rate ◽  
False Negative ◽  
Ground Beef ◽  
Current Method ◽  
Immunomagnetic Separation ◽  
Test Portion ◽  
E Coli ◽  
Molecular Tests ◽  
Modified Method ◽  
Reference Methods

Abstract The SASTM Molecular Tests method for the detection of E. coli O157 in various food matrixes has been certified by the AOAC Research Institute and designated Performance Tested MethodSM No. 031203. The current method modification includes the optional immunomagnetic separation (IMS) to enrich the bacteria as well as optional visual fluorescence readout without the use of a turbidimeter. The following study was conducted to validate the proposed modifications against the U. S. Department of Agriculture/Food Safety and Inspection Service Microbiology Laboratory Guidebook (MLG) and the U. S. Food and Drug Administration Bacteriological Analytical Manual (BAM) reference methods. E. coli O157:H7 ATCC 35150 and NM (non-motile) 700377 strains were used to inoculate the ground beef, beef trim, and spinach to obtain 20 low (0.23–2 CFU/test portion) and five high levels (3–5 CFU/test portion) of inoculations. Enriched samples were tested directly and subjected to anti-E. coli IMS prior to the SAS Molecular Tests. Results were determined via visual fluorescence and via turbidity using a turbidimeter. All the replicates, irrespective of the results, were confirmed using MLG 5.05 or BAM Chapter 4A methods. Results indicated that there were no significant differences in the detection of fractional positives (5–15 positives out of 20 replicates) with any of the methods tested above as compared to the reference methods. No false positives or negatives were detected except for two in the ground beef with IMS+Turbidity method. No false-negative samples were detected. Statistical analysis indicated that the modified methods were equivalent to the reference methods in detecting E. coli O157:H7 in the food matrixes tested. SAS Molecular Tests E. coli O157 Detection Kit can be used to detect E. coli O157:H7 in ground beef, beef trim, and spinach. The inclusion of IMS in the modified method improved the detection rate of E. coli O157:H7 in spinach and showed comparable detection rate in ground beef and beef trim. The optional use of visual fluorescent reagent and heat block either with IMS or without IMS produced results that were comparable to the results obtained from using a real-time turbidimeter.

SAS™ Molecular Tests Salmonella Detection Kit

2014 ◽  
Vol 97 (3) ◽  
pp. 808-819 ◽  
Author(s):  
Chandra Bapanpally ◽  
Laura Montier ◽  
Shah Khan ◽  
Akif Kasra ◽  
Sharon L Brunelle
Keyword(s):  
Hold Time ◽  
Ground Beef ◽  
Department Of Agriculture ◽  
Test Portion ◽  
Method Performance ◽  
Molecular Tests ◽  
Amplification Method ◽  
Chicken Carcass ◽  
Inspection Service ◽  
The U.S

Abstract The SAS™ Molecular tests Salmonella Detection method, a Loop-mediated Isothermal Amplification method, performed as well as or better than the U.S. Department of Agriculture-Food Safety Inspection Service Microbiology Laboratory Guidebook and the U.S. Food and Drug Administration Bacteriological Analytical Manual reference methods for ground beef, beef trim, ground turkey, chicken carcass rinses, bagged mixed lettuce, and fresh spinach. The ground beef (30% fat, 25 g test portion), poultry matrixes and leafy greens were validated in a 6–7 h enrichment, and ground beef (30% fat, 375 g composite test portion) and beef trim (375 g composite test portion) were validated in a 16–20 h enrichment. The method performance for meat and leafy green matrixes was shown to be acceptable under conditions of co-enrichment with Escherichia coli O157. Thus, after a short 6–7 h co-enrichment step, ground beef, beef trim, lettuce, and spinach can be tested for both Salmonella and E. coli O157. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 100 Salmonella serovars and 30 non- Salmonella species examined. The method was shown to be robust when enrichment time, DNA extract hold time, and DNA volume were varied.

Evaluation of the 3M™ Molecular Detection Assay (MDA) 2 – Salmonella for the Detection of Salmonella spp. in Select Foods and Environmental Surfaces: Collaborative Study, First Action 2016.01

2016 ◽  
Vol 99 (4) ◽  
pp. 980-997 ◽  
Author(s):  
Patrick Bird ◽  
Jonathan Flannery ◽  
Erin Crowley ◽  
James R Agin ◽  
David Goins ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Molecular Detection ◽  
Peanut Butter ◽  
Collaborative Study ◽  
Reference Method ◽  
Salmonella Spp ◽  
Inoculum Level ◽  
Test Portion ◽  
Detection Assay ◽  
The U.S

Abstract The 3M™ Molecular Detection Assay (MDA) 2 – Salmonella uses real-time isothermal technology for the rapid and accurate detection of Salmonella spp. from enriched select food, feed, and food-process environmental samples. The 3M MDA 2 – Salmonella was evaluated in a multilaboratory collaborative study using an unpaired study design. The 3M MDA 2 – Salmonella was compared to the U.S. Food and Drug Administration Bacteriological Analytical Manual Chapter 5 reference method for the detection of Salmonella in creamy peanut butter, and to the U.S. Department of Agriculture, Food Safety and Inspection Service Microbiology Laboratory Guidebook Chapter 4.08 reference method “Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg and Catfish Products and Carcass and Environmental Samples” for the detection of Salmonella in raw ground beef (73% lean). Technicians from 16 laboratories located within the continental United States participated. Each matrix was evaluated at three levels of contamination: an uninoculated control level (0 CFU/test portion), a low inoculum level (0.2–2 CFU/test portion), and a high inoculum level (2–5 CFU/test portion). Statistical analysis was conducted according to the probability of detection (POD) statistical model. Results obtained for the low inoculum level test portions produced difference in collaborator POD values of 0.03 (95% confidence interval, −0.10 to 0.16) for raw ground beef and 0.06 (95% confidence interval, −0.06 to 0.18) for creamy peanut butter, indicating no statistically significant difference between the candidate and reference methods.

scholarly journals USDA FSIS and FDA BAM Culture Methods BBL CHROMagar Salmonella Prepared Plated and Difco Dehydrated Culture Media

2009 ◽  
Vol 92 (2) ◽  
pp. 459-470 ◽  
Author(s):  
Vicki Ritter ◽  
Nancy Dick
Keyword(s):  
Culture Media ◽  
False Positive Rate ◽  
Ground Beef ◽  
Reference Method ◽  
Chi Square ◽  
Shell Eggs ◽  
Reference Methods ◽  
Raw Fish ◽  
Chi Square Analysis ◽  
The U.S

Abstract BBL and Difco CHROMagar Salmonella (CS) was evaluated internally and externally for the recovery of Salmonella in raw chicken, raw ground beef, raw fish, lettuce, and shell eggs. The raw chicken and ground beef were processed according to the U.S. Department of Agriculture, Food Safety and Inspection Service reference methods. The raw fish, lettuce, and shell eggs were processed according to the U.S. Food and Drug Administration, Bacteriological Analytical Manual procedures. Only raw chicken was found to be naturally contaminated with Salmonella; all other matrixeswere seededwith an appropriate dilution of organism to achieve fractionally positive results. Salmonella strains were permitted to equilibrate with the culture-negative matrixes for 48 h at 4C. Twenty 25 g samples of each food matrix plus 5 uninoculated samples were processed. CS prepared plates (CS PPM) and laboratory prepared plates from dehydrated culture media (CS DCM) were evaluated with the reference method media. A total of 16 positive cultures were obtained from the raw chicken samples, 17 in the raw ground beef, 18 in the raw fish and lettuce, and 11 in the shell eggs. A Chi-square analysis was performed on each of the food matrixes. BBL CS produced comparable results with the reference methods on all matrixes, resulting in a method agreement of 100 based on the Chi-square results. In testing known isolates the sensitivity and specificity was determined to be 94. Specificity improved to 98 when tetrathionate broth enrichment was used. A negative- and false-positive rate of 6 was found with known isolates. No false negatives were found in testing the food matrixes. The performance of the CS prepared plate and laboratory prepared plate was identical.

scholarly journals Methods for the Recovery of Salmonella spp. from Carboxymethylcellulose Gum, Gum Ghatti, and Gelatin

1998 ◽  
Vol 81 (4) ◽  
pp. 721-726 ◽  
Author(s):  
René Miguel Amaguaña ◽  
Thomas S Hammack ◽  
Wallace H Andrews
Keyword(s):  
Final Concentration ◽  
Inorganic Salts ◽  
Most Probable Number ◽  
Salmonella Spp ◽  
Test Portion ◽  
Probable Number ◽  
Ph Adjustment ◽  
Gum Ghatti ◽  
Thickening Agents ◽  
The U.S

Abstract Foods analyzed for Salmonella spp. by the procedure in the U.S. Food and Drug Administration's Bacteriological Analytical Manual are preenriched at a 1:9 test portion/broth ratio. Various thickening agents preenriched at this ratio become viscous and nonpipettable after 24 h incubation at 35 C. The effects of 3 factors (presence of inorganic salts, adjustment of pH, and presence of enzymes) on the viscosity of the test portion/preenrichment mixtures of various thickening agents during incubation were determined. Reduction of the viscosities of these thickening agents was accomplished as follows: carboxymethylcellulose gum, addition of cellulase to a final concentration of 0.10℅ in lactose broth preenrichment and incubation with no pH adjustment; gum ghatti, addition of NaCI to a final concentration of 0.10℅ in lactose broth preerichment and adjustment of the pH to 6.5; and gelatin, addition of papain to a final concentration of 0.10℅ in lactose broth preenrichment and adjustment of the pH to 6.8. With these modified preenrichments, one Salmonella spp. cell/25 g (representing an approximate most probable number value of 0.04 cell/g) was generally recovered from the thickening agents.

scholarly journals In-House Validation Study of the DuPont Qualicon BAX System Q7 Instrument with the BAX System PCR Assay for Salmonella (Modification of AOAC Official MethodSM 2003.09 and AOAC Research Institute Performance-Tested MethodSM 100201)

2009 ◽  
Vol 92 (3) ◽  
pp. 989-994 ◽  
Author(s):  
George Tice ◽  
Bridget Andaloro ◽  
H Kirk White ◽  
Lance Bolton ◽  
Siqun Wang ◽  
...  
Keyword(s):  
Validation Study ◽  
Reference Method ◽  
Pcr Assay ◽  
Paired Samples ◽  
Reference Methods ◽  
Comparable Performance ◽  
Aoac Official ◽  
Inspection Service ◽  
Positive Results ◽  
The U.S

Abstract In 2006, DuPont Qualicon introduced the BAX<sup/> system Q7 instrument for use with its assays. To demonstrate the equivalence of the new and old instruments, a validation study was conducted using the BAX system PCR Assay for Salmonella, AOAC Official MethodSM 2003.09, on three food types. The foods were simultaneously analyzed with the BAX system Q7 instrument and either the U.S. Food and Drug Administration Bacteriological Analytical Manual or the U.S. Department of AgricultureFood Safety and Inspection Service Microbiology Laboratory Guidebook reference method for detecting Salmonella. Comparable performance between the BAX system and the reference methods was observed. Of the 75 paired samples analyzed, 39 samples were positive by both the BAX system and reference methods, and 36 samples were negative by both the BAX system and reference methods, demonstrating 100 correlation. Inclusivity and exclusivity for the BAX system Q7 instrument were also established by testing 50 Salmonella strains and 20 non-Salmonella isolates. All Salmonella strains returned positive results, and all non-Salmonella isolates returned a negative response.

MicroSEQ® Salmonella spp. Detection Kit Using the Pathatrix® 10-Pooling Salmonella spp. Kit Linked Protocol Method Modification

2014 ◽  
Vol 97 (2) ◽  
pp. 484-491 ◽  
Author(s):  
Jason Wall ◽  
Rick Conrad ◽  
Kathy Latham ◽  
Eric Liu
Keyword(s):  
Real Time ◽  
Study Design ◽  
Foodborne Pathogens ◽  
Real Time Pcr ◽  
Reference Method ◽  
Immunomagnetic Separation ◽  
Pcr Analysis ◽  
Salmonella Spp ◽  
Culture Methods ◽  
Design For All

Abstract Real-time PCR methods for detecting foodborne pathogens offer the advantages of simplicity and quick time to results compared to traditional culture methods. The addition of a recirculating pooled immunomagnetic separation method prior to real-time PCR analysis increases processing output while reducing bothcost and labor. This AOAC Research Institute method modification study validates the MicroSEQ®Salmonella spp. Detection Kit [AOAC Performance Tested Method(PTM) 031001] linked with the Pathatrix® 10-Pooling Salmonella spp. Kit (AOAC PTM 090203C) in diced tomatoes, chocolate, and deli ham. The Pathatrix 10-Pooling protocol represents a method modification of the enrichment portion of the MicroSEQ Salmonella spp. protocol. The results of the method modification were compared to standard cultural reference methods for diced tomatoes, chocolate, and deli ham. All threematrixes were analyzed in a paired study design. An additional set of chocolate test portions was analyzed using an alternative enrichment medium in an unpaired study design. For all matrixes tested, there were no statistically significant differences in the number of positive test portions detected by the modified candidate method compared to the appropriate reference method. The MicroSEQ Salmonella spp. protocol linked with the Pathatrix individual or 10-Pooling procedure demonstrated reliabilityas a rapid, simplified, method for the preparation of samples and subsequent detection of Salmonella in diced tomatoes, chocolate, and deliham.

Evaluation of the 3M™ Petrifilm™ Salmonella Express System for the Detection of Salmonella Species in Selected Foods: Collaborative Study

2014 ◽  
Vol 97 (6) ◽  
pp. 1563-1575 ◽  
Author(s):  
Patrick Bird ◽  
Jonathan Flannery ◽  
Erin Crowley ◽  
James Agin ◽  
David Goins ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Control Level ◽  
Ground Beef ◽  
Reference Method ◽  
Probability Of Detection ◽  
Isolation And Identification ◽  
Inoculum Level ◽  
Test Portion ◽  
Dog Food ◽  
The U.S

Abstract The 3M™ Petrifilm™Salmonella Express (SALX) System is a simple, ready-to-use chromogenic culture medium system for the rapid qualitative detection and biochemical confirmation of Salmonella spp. in food and food process environmental samples. The 3M Petrifilm SALX System was compared using an unpaired study design in a multilaboratory collaborative study to the U.S. Department of Agriculture/Food Safety and Inspection Service (USDA/FSIS) Microbiology Laboratory Guidebook (MLG) 4.07 (2013) Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg and Catfish Products and Carcass and Environmental Sponges for raw ground beef and the U.S. Food and Drug Administration Bacteriological Analytical Manual (FDA/BAM) Chapter 5, Salmonella (2011) reference method for dry dog food following the current AOAC validation guidelines. For this study, a total of 17 laboratories located throughout the continental United States evaluated 1872 test portions. For the 3M Petrifilm SALX System, raw ground beef was analyzed using 25 g test portions, and dry dog food was analyzed using 375 g test portions. For the reference methods, 25 g test portions of each matrix were analyzed. The two matrices were artificially contaminated with Salmonella at three inoculation levels: an uninoculated control level (0 CFU/test portion), a low inoculum level (0.2–2 CFU/test portion), and a high inoculum level (2–5 CFU/test portion). Each inoculation level was statistically analyzed using the probability of detection statistical model. For the raw ground beef and dry dog food test portions, no significant differences at the 95% confidence interval were observed in the number of positive samples detected by the 3M Petrifilm SALX System versus either the USDA/FSIS-MLG or FDA/BAM methods.

scholarly journals RAPID' Salmonella Chromogenic Medium

2009 ◽  
Vol 92 (6) ◽  
pp. 1871-1875 ◽  
Author(s):  
Wendy F Lauer ◽  
Frederic L Martinez ◽  
Thomas Hammack
Keyword(s):  
Sensitivity And Specificity ◽  
Emergency Response ◽  
Esterase Activity ◽  
Peanut Butter ◽  
Reference Method ◽  
Chromogenic Substrate ◽  
Salmonella Spp ◽  
Chromogenic Medium ◽  
Subsequent Recall ◽  
The U.S

Abstract RAPID' Salmonella is a chromogenic medium for isolation and detection of Salmonella spp. in food, based on two enzymatic activities. All presumptive Salmonella-positive colonies are magenta, including lactose-positive Salmonella. S. Typhi, and S. Paratyphi serotypes, due to detection of C8 esterase activity. In order to differentiate Salmonella from other Enterobacteriaceae, the medium includes a second chromogenic substrate. As part of an Emergency Response Validation due to a massive outbreak and subsequent recall, peanut butter was tested to compare the performance of RAPID' Salmonella to the U.S. Food and Drug Administration's Bacteriological Analytical Manual reference method for detection of Salmonella. Sensitivity and specificity for RAPID' Salmonella were 100.

scholarly journals Validation of the One Broth One Plate for Salmonella Method for Detection of Salmonella Spp. in Select Food and Environmental Samples: AOAC Performance Tested MethodSM 102002

2020 ◽  
Author(s):  
Susan Alles ◽  
Brooke Roman ◽  
Quynh-Nhi Le ◽  
Magdalena Kurteu ◽  
Ezzeddine Elmerhebi ◽  
...  
Keyword(s):  
Validation Study ◽  
Environmental Samples ◽  
Reference Method ◽  
Black Pepper ◽  
Single Step ◽  
Probability Of Detection ◽  
Stainless Steel Surface ◽  
Salmonella Spp ◽  
Simple Method ◽  
The U.S

Abstract Background One Broth One Plate for Salmonella (OBOP Salmonella) is a rapid and simple method for detection of Salmonella spp. in food and environmental samples using traditional culture methodology. The method utilizes single-step enrichment followed by plating to a selective/differential, chromogenic agar. Objective The purpose of the validation study was to measure the effectiveness of the OBOP Salmonella method in comparison to reference culture procedures. Methods Performance of the OBOP Salmonella method was compared to that of the U.S. Food and Drug Administration Bacteriological Analytical Manual Chapter 5 reference method for queso fresco, smoked salmon, cantaloupe, chocolate, black pepper, chili powder, dry pet food, and sponge samples from a stainless steel surface, or to that of the U.S. Department of Agriculture Microbiology Laboratory Guidebook Chapter 4.10 method for raw ground turkey, chicken carcass rinse, and pasteurized liquid egg. Inclusivity/exclusivity, robustness, and stability/lot-to-lot consistency testing was also performed. Results In the matrix study, there were no statistically significant differences in performance between the OBOP Salmonella and reference methods, as determined by probability of detection analysis (P < 0.05), for any of the matrixes examined. All 104 Salmonella spp. strains produced positive results in inclusivity testing, and all 33 non-salmonellae exclusivity strains tested negative with the OBOP Salmonella method. Conclusions Results of the validation study show that the OBOP Salmonella method is a reliable procedure for detection of Salmonella spp. in select matrixes. The method is simple to perform, requires no specialized equipment, and produces results in as little as 37 h.

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