Food Safety And Inspection Service Research Articles

Treatment with a low pH processing aid to reduce Campylobacter counts on broiler parts

New regulations and performance standards for Campylobacter have been implemented by the USDA - Food Safety and Inspection Service (FSIS). The objective of this study was to evaluate treatment with a low pH processing aid (CMS1 PoultrypHresh), a formulated low pH processing aid, to reduce numbers of Campylobacter which could help companies meet regulatory requirements. Two experiments (3 replicates each) were conducted. Experiment 1, in each of 3 replicates, skin-on split chicken breasts (n = 15) were obtained from a local grocery and divided into groups of 5. The skin of each part was inoculated with approximately 107 cells of a gentamicin resistant C. coli (CCGR) marker strain in an area of approximately 6.5 cm2. CCGR cells were allowed to attach for 5 min prior to treatment. Ten inoculated breasts were individually placed into separate 6 L plastic storage boxes containing either 3.5 L deionized water or PoultrypHresh solution at a pH of 1.4. Parts were subjected to agitation (bubbled air) for 25 s. After treatment, each part was removed, allowed to drain for 5 s, and placed into a plastic bag prior to mechanical rinsing with 150 mL of buffered peptone water for 60 s. Five inoculated breasts served as controls, were untreated with a dip or agitation and sampled as above. Experiment 2 procedures were repeated using skin-on thighs under the same conditions. Rinsates were collected from each chicken part, serially diluted, and plated onto Campy Cefex agar with 200 ppm gentamicin (CCGen). All plates were incubated microaerobically (5% O2, 10% CO2, 85% N2) for 48 h at 42°C, colonies were counted and the cfu/mL was log transformed. The use of PoultrypHresh on split breast produced a 99.6% reduction compared to untreated controls, while thighs showed a 99.4% reduction. This study demonstrated an approximate 3 log reduction (P < 0.05) using a 25 s air agitation treatment in PoultrypHresh at pH 1.4 with no observable damage, which will help processors meet FSIS regulations.

Nutrient Analysis of Grain-Finished and Grass-Finished Lamb

ObjectivesThe 2015 Dietary Guidelines for Americans recommend consumption of nutrient dense foods while emphasizing that intake of total fat, saturated fat, and trans fat while emphasizing the benefit of consuming nutrient dense food from all 5 food groups as part of a healthy eating pattern (USDA & USDHH, 2015). With the implementation of the Food Safety and Inspection Service (FSIS) final rule (75 FR 82148) requiring nutritional labeling on many lamb cuts, it is essential to have current, accurate nutrient data that reflects the current U.S. supply. Data currently available in the United States Nutrient Database for Standard Reference (SR) for U.S. Lamb are largely outdated. Lamb data currently available in the SR originated from the work of Ono et al. (1984) and Lin et al. (1988). The objective of this study was to analyze nutrient composition of eleven raw and cooked grain-finished and grass-finished lamb cuts to update nutrient data in the USDA National Nutrient Database for Standard Reference (SR).Materials and MethodsRetail packages of foreshanks, whole legs, sirloin chops, whole loins, loin chops, whole frenched rib roasts, frenched rib chops, whole rib roasts, rib chops, whole shoulders, shoulder blade chops, shoulder arm chops, stew meat, and ground lamb (IMPS # 210, 234, 1245, 232A, 1232A, 204D, 1204D, 204B, 1204B, 208, 1207B, 1207A, 295, and 296) were collected during all four seasons of the year from 3 U.S. suppliers representing the vast majority of lamb entering the retail market. Packages were transported to the Colorado State University Meat Laboratory for retail cut dissection (separated into separable lean, external fat, seam fat and refuse), cooking, and nutrient analysis. Single composites of separable lean homogenates were formed from grain-finished and grass-finished lamb cuts and single composites of seam and external fat for analysis of proximates, fatty acids, vitamins, and minerals using AOAC (1995) methodologies at USDA approved laboratories. Least squares means of dissected separable components from lamb cuts were compared.ResultsResults from this study generated greater identification of fatty acid profiles, resulted in lower fat content, provided updated nutrient composition for inclusion into the SR, and established nutrient composition for grass-finished lamb cuts. These data demonstrated that 10 grain-finished and grass-finished lamb cuts qualify for USDA Lean labeling claims, and 4 grain-finished and 2 grass-finished cuts qualify for USDA extra lean labeling claims. Lamb cuts qualify as an, “excellent source of” 6 essential nutrients, and “good source of” 3 essential nutrients.ConclusionThese findings were submitted to the USDA Nutrient Database for Standard Reference (SR) to update nutrient information available for retail lamb cuts to consumers, the general public, health and nutrition organizations, as well as health professionals. Results from this study have been used to establish raw and cooked nutrient data for grass-finished lamb cuts in the SR. These data indicate that lamb can be included as part of a healthy diet providing excellent and good sources of protein, B-vitamins and several essential minerals.

Nutrient Analysis of Grain-Finished and Grass-Finished Lamb

ObjectivesThe 2015 Dietary Guidelines for Americans recommend consumption of nutrient dense foods while emphasizing that intake of total fat, saturated fat, and trans fat while emphasizing the benefit of consuming nutrient dense food from all 5 food groups as part of a healthy eating pattern (USDA & USDHH, 2015). With the implementation of the Food Safety and Inspection Service (FSIS) final rule (75 FR 82148) requiring nutritional labeling on many lamb cuts, it is essential to have current, accurate nutrient data that reflects the current U.S. supply. Data currently available in the United States Nutrient Database for Standard Reference (SR) for U.S. Lamb are largely outdated. Lamb data currently available in the SR originated from the work of Ono et al. (1984) and Lin et al. (1988). The objective of this study was to analyze nutrient composition of eleven raw and cooked grain-finished and grass-finished lamb cuts to update nutrient data in the USDA National Nutrient Database for Standard Reference (SR). Materials and MethodsRetail packages of foreshanks, whole legs, sirloin chops, whole loins, loin chops, whole frenched rib roasts, frenched rib chops, whole rib roasts, rib chops, whole shoulders, shoulder blade chops, shoulder arm chops, stew meat, and ground lamb (IMPS # 210, 234, 1245, 232A, 1232A, 204D, 1204D, 204B, 1204B, 208, 1207B, 1207A, 295, and 296) were collected during all four seasons of the year from 3 U.S. suppliers representing the vast majority of lamb entering the retail market. Packages were transported to the Colorado State University Meat Laboratory for retail cut dissection (separated into separable lean, external fat, seam fat and refuse), cooking, and nutrient analysis. Single composites of separable lean homogenates were formed from grain-finished and grass-finished lamb cuts and single composites of seam and external fat for analysis of proximates, fatty acids, vitamins, and minerals using AOAC (1995) methodologies at USDA approved laboratories. Least squares means of dissected separable components from lamb cuts were compared. ResultsResults from this study generated greater identification of fatty acid profiles, resulted in lower fat content, provided updated nutrient composition for inclusion into the SR, and established nutrient composition for grass-finished lamb cuts. These data demonstrated that 10 grain-finished and grass-finished lamb cuts qualify for USDA Lean labeling claims, and 4 grain-finished and 2 grass-finished cuts qualify for USDA extra lean labeling claims. Lamb cuts qualify as an, “excellent source of” 6 essential nutrients, and “good source of” 3 essential nutrients. ConclusionThese findings were submitted to the USDA Nutrient Database for Standard Reference (SR) to update nutrient information available for retail lamb cuts to consumers, the general public, health and nutrition organizations, as well as health professionals. Results from this study have been used to establish raw and cooked nutrient data for grass-finished lamb cuts in the SR. These data indicate that lamb can be included as part of a healthy diet providing excellent and good sources of protein, B-vitamins and several essential minerals.

Using a Six Sigma Fishbone Analysis Approach To Evaluate the Effect of Extreme Weather Events on Salmonella Positives in Young Chicken Slaughter Establishments

A six sigma fishbone analysis approach was used to develop a machine learning model in SAS, Version 9.4, by using stepwise linear regression. The model evaluated the effect of a wide variety of variables, including slaughter establishment operational measures, normal (30-year average) weather, and extreme weather events on the rate of Salmonella -positive carcasses in young chicken slaughter establishments. Food Safety and Inspection Service (FSIS) verification carcass sampling data, as well as corresponding data from the National Oceanographic and Atmospheric Administration and the Federal Emergency Management Agency, from September 2011 through April 2015, were included in the model. The results of the modeling show that in addition to basic establishment operations, normal weather patterns, differences from normal and disaster events, including time lag weather and disaster variables, played a role in explaining the Salmonella percent positive that varied by slaughter volume quartile. Findings show that weather and disaster events should be considered as explanatory variables when assessing pathogen-related prevalence analysis or research and slaughter operational controls. The apparent significance of time lag weather variables suggested that at least some of the impact on Salmonella rates occurred after the weather events, which may offer opportunities for FSIS or the poultry industry to implement interventions to mitigate those effects.

Validation of the Applied Biosystems RapidFinder Shiga Toxin-Producing E. coli (STEC) Detection Workflow.

The Applied Biosystems™ RapidFinder™ STEC Detection Workflow (Thermo Fisher Scientific) is a complete protocol for the rapid qualitative detection of Escherichia coli (E. coli) O157:H7 and the "Big 6" non-O157 Shiga-like toxin-producing E. coli (STEC) serotypes (defined as serogroups: O26, O45, O103, O111, O121, and O145). The RapidFinder STEC Detection Workflow makes use of either the automated preparation of PCR-ready DNA using the Applied Biosystems PrepSEQ™ Nucleic Acid Extraction Kit in conjunction with the Applied Biosystems MagMAX™ Express 96-well magnetic particle processor or the Applied Biosystems PrepSEQ Rapid Spin kit for manual preparation of PCR-ready DNA. Two separate assays comprise the RapidFinder STEC Detection Workflow, the Applied Biosystems RapidFinder STEC Screening Assay and the Applied Biosystems RapidFinder STEC Confirmation Assay. The RapidFinder STEC Screening Assay includes primers and probes to detect the presence of stx1 (Shiga toxin 1), stx2 (Shiga toxin 2), eae (intimin), and E. coli O157 gene targets. The RapidFinder STEC Confirmation Assay includes primers and probes for the "Big 6" non-O157 STEC and E. coli O157:H7. The use of these two assays in tandem allows a user to detect accurately the presence of the "Big 6" STECs and E. coli O157:H7. The performance of the RapidFinder STEC Detection Workflow was evaluated in a method comparison study, in inclusivity and exclusivity studies, and in a robustness evaluation. The assays were compared to the U.S. Department of Agriculture (USDA), Food Safety and Inspection Service (FSIS) Microbiology Laboratory Guidebook (MLG) 5.09: Detection, Isolation and Identification of Escherichia coli O157:H7 from Meat Products and Carcass and Environmental Sponges for raw ground beef (73% lean) and USDA/FSIS-MLG 5B.05: Detection, Isolation and Identification of Escherichia coli non-O157:H7 from Meat Products and Carcass and Environmental Sponges for raw beef trim. No statistically significant differences were observed between the reference method and the individual or combined kits forming the candidate assay using either of the DNA preparation kits (manual or automated extraction). For the inclusivity and exclusivity evaluation, the RapidFinder STEC Detection Workflow, comprising both RapidFinder STEC screening and confirmation kits, correctly identified all 50 target organism isolates and correctly excluded all 30 nontarget strains for both of the assays evaluated. The results of these studies demonstrate the sensitivity and selectivity of the RapidFinder STEC Detection Workflow for the detection of E. coli O157:H7 and the "Big 6" STEC serotypes in both raw ground beef and beef trim. The robustness testing demonstrated that minor variations in the method parameters did not impact the accuracy of the assay and highlighted the importance of following the correct incubation temperatures.

Factors associated with recovery of meat products following recalls due to Shiga toxin-producing Escherichia coli.

Food-product recall data for recalls due to Shiga toxin-producing Escherichia coli (STEC) from 2000 to 2012 were obtained for establishments regulated by the United States Department of Agriculture, Food Safety and Inspection Service (FSIS). Statistical tests were used to assess the factors associated with recovery of product following STEC recalls along with the relationship between cluster detection and jurisdictions. Our results indicated that the percentage of recalled product recovered following a recall action due to STEC was dependent on the complexity of distribution, type of distribution, amount of time between production and recall dates, and the number of pounds of product recalled. Illness-related STEC recalls were associated with a lower percentage of product recovery which was probably impacted by larger amounts of product recalled, broader production scope, and delays from epidemiological and traceback investigations. Further, detection of illnesses related to STEC recalls seemed to be enhanced in states with additional resources and a history of successful foodborne investigations. This makes an argument for additional resources dedicated to public health agencies specifically for the surveillance of foodborne illnesses.

Foodborne Outbreaks Reported to the U.S. Food Safety and Inspection Service, Fiscal Years 2007 through 2012

The U.S. Department of Agriculture's Food Safety and Inspection Service (FSIS) works closely with federal, state, and local public health partners to investigate foodborne illness outbreaks associated with its regulated products. To provide insight into outbreaks associated with meat and poultry, outbreaks reported to FSIS during fiscal years 2007 through 2012 were evaluated. Outbreaks were classified according to the strength of evidence linking them to an FSIS-regulated product and by their epidemiological, etiological, and vehicle characteristics. Differences in outbreak characteristics between the period 2007 through 2009 and the period 2010 through 2012 were assessed using a chi-square test or Mann-Whitney U test. Of the 163 reported outbreaks eligible for analysis, 89 (55%) were identified as possibly linked to FSIS-regulated products and 74 (45%) were definitively linked to FSIS-regulated products. Overall, these outbreaks were associated with 4,132 illnesses, 772 hospitalizations, and 19 deaths. Shiga toxin-producing Escherichia coli was associated with the greatest proportion of reported outbreaks (55%), followed by Salmonella enterica (34%) and Listeria monocytogenes (7%). Meat and poultry products commercially sold as raw were linked to 125 (77%) outbreaks, and of these, 105 (80%) involved beef. Over the study period, the number of reported outbreaks definitively linked to FSIS-regulated products (P = 0.03) declined, while the proportion of culture-confirmed cases (P = 0.0001) increased. Our findings provide insight into the characteristics of outbreaks associated with meat and poultry products.

Salmonella isolated from ready-to-eat pasteurized liquid egg products: Thermal resistance, biochemical profile, and fatty acid analysis

The Egg Products Inspection Act of 1970 requires that egg products in the U.S. must be pasteurized prior to release into commerce. The USDA Food Safety and Inspection Service (FSIS) is responsible for regulating egg products. Salmonellae are infrequently isolated from pasteurized egg products by food manufacturers or the FSIS and may be present as a result of either pasteurization-resistant bacteria or post-processing contamination. In this study, seventeen strains of Salmonella isolated from pasteurized egg products and three heat-resistant control strains were compared for the following attributes: thermal resistance in liquid whole egg (LWE) at 60°C, enzymatic profiles, and serotyping and phage typing, antibiotic susceptibility, fatty acid analysis and strain morphological variation evaluated by scanning electron microscopy. Isolates were serotyped as Heidelberg (4 isolates), Widemarsh, Mbandaka, Cerro, Thompson, 4,12:i:-, and Enteritidis (8 isolates). All 20 isolates were sensitive to all 14 antibiotics tested for. The D60 values in LWE ranged from 0.34 to 0.58min. All 20 strains were recovered from LWE inoculated with 8.5logCFU/mL of Salmonella and pasteurized at 60°C for 3.5min; however, some isolates were not recovered from pasteurized LWE that had been inoculated with only 4.5logCFU/mL Salmonella and treated at 60°C for 3.5min. Although some strains exhibited atypical enzymatic activity (e.g., reduction of adonitol, hydrolysis of proline nitroanilide or p-n-p-beta-glucuronide, and nonreduction of melibiose), differences in biochemical reactions could not be correlated with differences in thermal resistance. Furthermore, fatty acid analysis revealed that differences insaturate/unsaturated profiles may be correlated with differences in heat resistance, in two instances. One heat resistant strain (#13, Enteritidis) had the statistically lowest unsaturated/saturate ratio at 39%. However, one heat sensitive strain (#3, serovar 4,12:i:-) had the highest unsaturated/saturate ratio at 81%, and also the lowest concentration of stearic acid. This data represents the first steps in determining whether Salmonella contamination in pasteurized egg products may be the result of either thermally-resistant isolates or post-processing contamination. Contamination of LWE by Salmonella strains with higher heat resistance, (e.g., isolate #'s 2, 6, 10 and 12) may indicate the ability of Salmonella to survive pasteurization, while contamination of LWE strains with lower heat resistance (e.g., isolate #'s 1, 3, 5, 7, 8, 11, and 15) may indicate post-processing contamination of LWE by this foodborne pathogen.

Use of the ecf1 Gene To Detect Shiga Toxin–Producing Escherichia coli in Beef Samples

Escherichia coli O157:H7 and six serovars (O26, O103, O121, O111, O145, and O45) are frequently implicated in severe clinical illness worldwide. Standard testing methods using stx, eae, and O serogroup–specific gene sequences for detecting the top six non-O157 STEC bear the disadvantage that these genes may reside, independently, in different nonpathogenic organisms, leading to false-positive results. The ecf operon has previously been identified in the large enterohemolysin-encoding plasmid of eae-positive Shiga toxin–producing E. coli (STEC). Here, we explored the utility of the ecf operon as a single marker to detect eae-positive STEC from pure broth and primary meat enrichments. Analysis of 501 E. coli isolates demonstrated a strong correlation (99.6%) between the presence of the ecf1 gene and the combined presence of stx, eae, and ehxA genes. Two large studies were carried out to determine the utility of an ecf1 detection assay to detect non-O157 STEC strains in enriched meat samples in comparison to the results using the U.S. Department of Agriculture Food Safety and Inspection Service (FSIS) method that detects stx and eae genes. In ground beef samples (n = 1,065), the top six non-O157 STEC were detected in 4.0% of samples by an ecf1 detection assay and in 5.0% of samples by the stx- and eae-based method. In contrast, in beef samples composed largely of trim (n = 1,097), the top six non-O157 STEC were detected at 1.1% by both methods. Estimation of false-positive rates among the top six non-O157 STEC revealed a lower rate using the ecf1 detection method (0.5%) than using the eae and stx screening method (1.1%). Additionally, the ecf1 detection assay detected STEC strains associated with severe illness that are not included in the FSIS regulatory definition of adulterant STEC.

Vivione Bioscience RAPID-B(®) E. coli O157 test kit and non-O157 STEC test kit evaluation.

RAPID-B(®) is a high performance, integrated microbiology/infectious disease diagnostic system. The system uses hardware and software that are specifically designed for optimal detection using custom, immuno-based reagents designed to react to cell surface antigens of the target bacteria. The Vivione Bioscience RAPID-B Escherichia coli O157 and non-O157 Shiga toxin-producing E. coli (STEC) kits were validated alongside the U.S. Department of Agriculture, Food Safety and Inspection Service (FSIS), Microbiology Laboratory Guidebook (MLG) 5.07 (for E. coli O157) and FSIS MLG 5B.04 (for non-O157 STEC) reference methods for the detection of E. coli O157 and STEC. The matrixes, ground beef and beef trim, were inoculated with appropriate CFU/test portion of E. coli O157 and STEC so as to generate fractional positives results, 5 to 15 positives out of 20 inoculated samples. Samples were enriched in prewarmed Brain Heart Infusion broth at 42 ± 1°C for 6.5-7.5 h or 8.5-9.5 h depending on the sample size. All samples were confirmed using the MLG reference method, regardless of initial screen result. The RAPID-B test methods were statistically equivalent to the reference method for the detection of E. coli O157 and STEC in all tested samples. Inclusivity and exclusivity testing of the RAPID-B methods showed 100% specificity for both kits. Finally, the RAPID-B test methods were shown to be robust when variations were applied to enrichment time, broth temperature, and vortexing time.

Advances in detection methods for Shiga toxin-producing Escherichia coli (STEC).

Advances in detection methods for Shiga toxin-producing Escherichia coli (STEC).

Factors associated with regulatory action involving investigation of illnesses associated with Shiga toxin-producing Escherichia coli in products regulated by the Food Safety and Inspection Service.

We described characteristics of the Escherichia coli O157 and Escherichia coli non-O157 illness investigations conducted by the United States Department of Agriculture's Food Safety and Inspection Service (FSIS) during the 5-year period from 2006 through 2010. We created a multivariable logistic regression model to determine characteristics of these investigations that were associated with FSIS regulatory action, which was defined as having occurred if a product recall occurred or if FSIS personnel performed an environmental health assessment (Food Safety Assessment) at the implicated establishment. During this period, FSIS took regulatory action in 38 of 88 (43%) investigations. Illness investigations in which FoodNet states were involved were more likely to result in regulatory action. Illness investigations in which state and local traceback, or FSIS traceback occurred were more likely to result in regulatory action. Reasons for lack of action included evidence of cross-contamination after the product left a regulated establishment, delayed notification, lack of epidemiological information, and insufficient product information.

Veriflow Campylobacter. Performance tested method 101201.

Veriflow Campylobacter is a molecular based assay for the presumptive and qualitative detection of the most common occurring foodborne Campylobacter species: C. jejuni and C. coli. The assay utilizes a PCR detection method coupled with a rapid, visual, flow-based assay that develops in 3 min post PCR amplification and requires only 24 h of non-specialized enrichment for maximum sensitivity. The Veriflow Campylobacter system eliminates the need for microaerobic chambers, gel electrophoresis or fluorophore based detection of target amplification, and does not require complex data analysis. This Performance Tested Method validation study demonstrated the ability of the Veriflow method to detect naturally occurring Campylobacterfrom chicken carcass rinsates. In the reference comparison study, Chi-square and probability of detection analyses of two unpaired studies indicated that there was no significant difference between the Veriflow Campylobacter method and the U.S. Department of Agriculture (USDA)/Food Safety and Inspection Service (FSIS) reference method. There was no indication of false positive or false negative detection in the reference comparison study, and all 50 C. jejuni and C. coli strains were detected, while 35 nonspecific organisms were undetected in the exclusivity/ inclusivity study. The study results show that Veriflow Campylobacter is a sensitive, selective and robust assay for the detection of C. jejuni and C. coli in chicken carcass rinsates.

Evaluation of a Multiplex Real-Time PCR Method for Detecting Shiga Toxin–Producing Escherichia coli in Beef and Comparison to the U.S. Department of Agriculture Food Safety and Inspection Service Microbiology Laboratory Guidebook Method

The "top-six" non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups (O26, O45, O103, O111, O121, and O145) most frequently associated with outbreaks and cases of foodborne illnesses have been declared as adulterants in beef by the U.S. Department of Agriculture Food Safety and Inspection Service (FSIS). Regulatory testing in beef began in June 2012. The purpose of this study was to evaluate the DuPont BAX System method for detecting these top six STEC strains and strains of E. coli O157:H7. For STEC, the BAX System real-time STEC suite was evaluated, including a screening assay for the stx and eae virulence genes and two panel assays to identify the target serogroups: panel 1 detects O26, O111, and O121, and panel 2 detects O45, O103, O145. For E. coli O157:H7, the BAX System real-time PCR assay for this specific serotype was used. Sensitivity of each assay for the PCR targets was ≥1.23 × 10(3) CFU/ml in pure culture. Each assay was 100% inclusive for the strains tested (20 to 50 per assay), and no cross-reactivity with closely related strains was observed in any of the assays. The performance of the BAX System methods was compared with that of the FSIS Microbiology Laboratory Guidebook (MLG) methods for detection of the top six STEC and E. coli O157:H7 strains in ground beef and beef trim. Generally, results of the BAX System method were similar to those of the MLG methods for detecting non-O157 STEC and E. coli O157:H7. Reducing or eliminating novobiocin in modified tryptic soy broth (mTSB) may improve the detection of STEC O111 strains; one beef trim sample inoculated with STEC O111 produced a negative result when enriched in mTSB with 8 mg/liter novobiocin but was positive when enriched in mTSB without novobiocin. The results of this study indicate the feasibility of deploying a panel of real-time PCR assay configurations for the detection and monitoring of the top six STEC and E. coli O157:H7 strains in beef. The approach could easily be adapted for additional multiplex assays should regulations expand to include other O serogroups or virulence genes.

Arsenic Levels in Chicken

I commend Nachman et al. (2013) on their careful study of arsenic content in market samples of chicken and am dismayed to learn that arsenic levels in chicken remain high despite our report of arsenic levels in Environmental Health Perspectives in 2004 (Lasky et al. 2004). One possible explanation is the very complicated lines of authority around the regulation of drugs fed to food animals, along with the enforcement of those regulations. Nachman et al. (2013) focused their discussion on the role of the Food and Drug Administration (FDA), but many other agencies participate in the regulation and enforcement of residue safety in food animals. As noted by the Food Safety and Inspection Service (FSIS) in the introduction to their 2012 Residue Sampling Plans (FSIS 2012), The U.S. National Residue Program (NRP) for Meat, Poultry, and Egg Products, administered by the USDA [U.S. Department of Agriculture] FSIS, is an interagency program designed to identify, rank and test for chemical contaminants in meat, poultry, and egg products. They continue, The NRP requires the cooperation and collaboration of several agencies for its successful design and implementation. The USDA FSIS, the EPA [U.S. Environmental Protection Agency], and the Department of Health and Human Services (DHHS) FDA are the primary federal agencies managing this program. The FDA, under the Federal Food, Drug, and Cosmetic Act, establishes tolerances for veterinary drugs, and action levels for food additives and environmental contaminants. The EPA, under the Federal Insecticide, Fungicide, and Rodenticide Act (as modified by the Food Quality Protection Act), establishes tolerance levels for registered pesticides…. Representatives from FSIS, FDA, EPA, the USDA Agricultural Research Service (ARS), the USDA Agricultural Marketing Service (AMS), and the DHHS Centers for Disease Control and Prevention (CDC) collaborate to develop the scheduled sampling program. Setting and enforcing safety levels involves several steps, one of which is the collection of meat and poultry samples, followed by statistical analysis, interpretation, and action. The NRP sampling plan is designed to identify samples with residues above the allowed levels. The data are then analyzed as categorical values (violation, no violation). Current methods of data analysis do not include estimation of mean values that can then be extrapolated to the national food supply. It was by analyzing the data as a continuous variable that my coauthors and I were able to describe the high levels of arsenic in chicken in 2004 (Lasky et al. 2004). Concerns about arsenic levels in chicken are of increasing importance because of the increased per capita consumption of chicken over the past decade (USDA Economic Research Service 2013).

Arsenic Levels in Chicken: Nachman et al. Respond

In our paper (Nachman et al. 2013) we focused on dietary arsenic exposure from the use of arsenic-based drugs in food animal production, specifically chicken. We thank Lasky for broadening the discussion on arsenic regulations for food to include federal agencies beyond the Food and Drug Administration (FDA). The results of our study (Nachman et al. 2013) indicate that the use of arsenic-based drugs increases the levels of inorganic arsenic in chicken meat. Based on these findings, we recommend banning the use of arsenic-based drugs in food animal production, which are under the jurisdiction of the FDA. It is important, however, to recognize the potential role that could be played by the U.S. Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS) under its National Residue Program (NRP). Under its mandate, the NRP facilitates the monitoring of arsenic levels in poultry products and supports enforcement actions for animal products in violation of arsenic standards (USDA FSIS 2012). Unfortunately, the NRP faces constraints (in addition to those noted by Lasky) that limit its effectiveness (Silbergeld and Nachman 2008). The most important of these constraints is the current arsenic standard for meat, which was set before 1963 (FDA 1963) and does not account for recent epidemiologic research. In addition, the standard applies to total arsenic concentrations rather than to inorganic arsenic, the species of greatest health relevance. Because arsenic can be present in food in various forms that have widely varying toxicity, standards might need to be species specific. The U.S. Environmental Protection Agency (EPA) is currently revising its toxicological assessment for inorganic arsenic (U.S. EPA 2010) as part of its Integrated Risk Information System (IRIS) program. The purpose of this revision is to produce health-based guidance that can be useful in setting arsenic standards in different media (including foods) that reflect our current understanding of dose–response relationships between arsenic exposures and adverse health outcomes. To achieve this goal, coordination between the FDA, U.S. EPA, and NRP is essential. By applying appropriate standards and methods with adequate sensitivity for the arsenic species of interest, the NRP could play a central role in minimizing dietary exposure to arsenic through animal products. Although sale of roxarsone remains suspended in the United States, nitarsone, a chemically similar arsenical drug, continues to be sold (Zoetis 2013). Industry statements in the media have confirmed nitarsone use in the turkey industry (Aubrey 2013), and the USDA estimates of per capita turkey consumption are increasing (USDA 2013). Research is needed to characterize potential contributions of nitarsone to inorganic arsenic concentrations in turkey meat. For these reasons, monitoring efforts remain relevant. In the absence of regulations that limit inorganic arsenic in our foods, the banning of arsenic-based drugs would minimize dietary arsenic exposures in poultry consumers.

Dietary Estimates of Dioxins Consumed in U.S. Department of Agriculture--Regulated Meat and Poultry Products

The U.S. Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS) examined whether levels of dioxin-like compounds (DLCs) measured in FSIS-regulated meat and poultry products indicate possible concern for U.S. public health based on usual and recommended consumption patterns of meat and poultry for the U.S. population. The FSIS estimated daily dietary exposures and compared them with the reference dose (RfD) established by the U.S. Environmental Protection Agency (EPA) for potential noncancer risks from 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), assuming that all measured DLCs were represented by the RfD (i.e., not just TCDD alone). The estimates indicate that a typical U.S. adult daily exposure of DLCs from FSIS-regulated products is below the EPA-established RfD. Only children consuming chronic average daily servings of meat or poultry products containing the highest measured levels of DLCs may exceed the RfD. If one follows the recommendations from the 2010 Dietary Guidelines for Americans, all expected exposures to DLCs from FSIS-regulated products are estimated to be well below the RfD.

Escherichia coli O157 in Ground Beef from Local Retail Markets in Pachuca, Mexico

Escherichia coli O157 strains have been recognized as pathogenic bacteria, of which raw beef is a known vehicle. An evaluation was done of the presence of E. coli O157 in ground beef from local retail markets in Pachuca, Hidalgo State, Mexico. A total of 120 ground beef samples (500 g) were tested for E. coli O157 by simultaneous application of the U. S. Department of Agriculture, Food Safety and Inspection Service (FSIS)'s Microbiology Laboratory Guidebook culture procedure 5.05, and two commercial kits, Reveal for E. coli O157:H7 and Visual Immunoprecipitate Assay (VIP) Gold for enterohemorrhagic E. coli. Two incubation times (8 and 20 h) were used with the commercial kits. Presence of stx1, stx2, and eaeA loci was determined by multiplex PCR. Of 360 subsamples (120 per procedure), 12 samples were found to be E. coli O157 positive by the FSIS culture method. With VIP, 73 subsamples were presumptive positive after 8 h of enrichment, and 60 were presumptive positive after 20 h of enrichment. Of these, only 6 (8 h) and 8 (20 h) subsamples were confirmed true positives with the FSIS method. With Reveal, 60 subsamples were presumptive positive after 8 h of enrichment and 50 were presumptive positive after 20 h of enrichment. Of these, only 6 (8 h) and 8 (20 h) subsamples were confirmed as true positives with the FSIS method. A total of 57 E. coli O157:H7 and 21 E. coli O157 strains were isolated. None of the O157 or O157:H7 strains had stx1 or stx2 loci, and only one had the eaeA locus. To our knowledge, this is the first report of the presence of E. coli O157 in commercial ground beef from Mexico, and the first report of isolation of a large number of stx-negative E. coli O157 and E. coli O157:H7 strains in Mexico.

Controlling Avoidance of Food Safety Regulations in Meat Packing Industry

The sale of meat and poultry contains asymmetric information dealing with food safety. Since pathogens in most cases are invisible, consumers lack information on the safety of meat and poultry. Government interaction through the Food Safety and Inspection Service (FSIS) in the meat and poultry industry is necessary to regulate the safety of meat and poultry products. Inevitably, any rules in society are likely to include violators. The cost of perfectly safe food is far too great for the industry to bear. The marginal gain in revenue from violating a regulation may be greater than the marginal cost. Violators of rules may resort to sophisticated means to avoid detection of the original violations. The means used to avoid detection may be legal or illegal. Effective regulation of avoidance activities will lead to lower violations of the original crime. Such regulations may be ex-ante or ex-post. This paper discusses potential effectiveness of ex-ante or ex-post regulations on avoidance activities of food safety regulations in the meat and poultry industry. The use of ex-ante measures such as contracting external service providers coupled with the threat of ex-post punishment on service providers would potentially decrease the number of avoidance activities and their associated original crime in the meat and poultry industry.

Development and validation of a streamlined method designed to detect residues of 62 veterinary drugs in bovine kidney using ultra‐high performance liquid chromatography – tandem mass spectrometry

In the USA, the US Department of Agriculture's Food Safety and Inspection Service (FSIS) conducts the National Residue Program designed to monitor veterinary drug and other chemical residues in beef and other slaughtered food animals. Currently, FSIS uses a 7-plate bioassay in the laboratory to screen for antimicrobial drugs in bovine kidneys from those animals tested positive by inspectors in the slaughter establishments. The microbial inhibition bioassay has several limitations in terms of monitoring scope, sensitivity, selectivity, and analysis time. Ultra-high performance liquid chromatography - tandem mass spectrometry (UHPLC-MS/MS) has many advantages over the bioassay for this application, and this study was designed to develop, evaluate, and validate a fast UHPLC-MS/MS method for antibiotics and other high-priority veterinary drugs in bovine kidney. Five existing multi-class, multi-residue methods from the literature were tested and compared, and each performed similarly. Experiments with incurred samples demonstrated that a 5-min shake of 2 g homogenized kidney with 10 ml of 4/1 (v/v) acetonitrile/water followed by simultaneous clean-up of the initial extract with 0.5 g C18 and 10 ml hexane gave a fast, simple, and effective sample preparation method for the <10 min UHPLC-MS/MS analysis. An extensive 5-day validation process demonstrated that the final method could be used to acceptably screen for 54 of the 62 drugs tested, and 50 of those met qualitative MS identification criteria. Quantification was not needed in the application, but the method gave ≥ 70% recoveries and ≤ 25% reproducibilities for 30 of the drugs.