Attachment C_Raw Pork Products Baseline - QADone - V7_MES EM Review 060719.pdf

Attachment C

Running Title: Salmonella and STEC in raw pork products

General Interest Paper

Salmonella and Shiga toxin‐producing Escherichia coli in products sampled in the Food Safety and

Inspection Service Raw Pork Baseline Study

1Maria E. Scott, 1Evelyne Mbandi, 1Stephanie Buchanan, 1Naser Abdelmajid, 1Christian Gonzalez‐Rivera, 2Jennifer Webb, 2Jennifer Green, 3Paul Dolan, 1Kis Robertson Hale

United States Department of Agriculture, Food Safety and Inspection Service, Washington, DC 20250, USA

1Office Public Health Science

2Office of Policy and Program Development

3Office of Planning, Analysis and Risk Management

Key words: Salmonella, STEC, raw pork products, survey for foodborne pathogens

*Author for correspondence. Tel: (202)‐690‐6619, Fax: (202)‐690‐6364; E‐mail:

maria.scott@fsis.usda.gov

ABSTRACT

The Food Safety and Inspection Service (FSIS) conducts microbiological baseline studies to determine national prevalence of select foodborne pathogens in federally‐inspected meat and poultry products and to obtain data for risk assessments. FSIS conducted a baseline to characterize and determine prevalence of Salmonella and assess the occurrence of Shiga toxin‐producing Escherichia coli

(STEC) in a variety of raw pork products. In total, 4145 samples from slaughter and processing establishments and tested for Salmonella; a subset of these samples (1476) from slaughter establishments were also tested for STEC. Analysis determined the national prevalence of Salmonella in raw pork products was highest in comminuted products (26.7%) followed by intact cuts (10.0%) and non‐intact cuts (6.0%). Less than one percent of tested samples were positive for STEC. Our findings indicate there is a need for pathogen reduction strategies for raw pork, in particular, comminuted pork products.

INTRODUCTION

As part of the Pathogen Reduction/Hazard Analysis Critical Control Points (PR/HACCP) System implemented in 1996, the United States Department of Agriculture’s Food Safety and Inspection Service

(USDA‐FSIS) established policies aimed at reducing pathogenic microorganisms on meat and poultry products, thereby reducing the incidence of foodborne illnesses associated with consuming these products. These policies included performance standards for Salmonella contamination. FSIS also mandated that establishments develop and implement HACCP plans to control and prevent hazards likely to occur during slaughter and processing (1). Foodborne pathogens are among the hazards that

HACCP plans are expected to address.

Each year, there are an estimated 48 million illnesses in the United States caused by foodborne pathogens resulting in approximately 128,000 hospitalizations and 3,000 deaths (2). Of the total foodborne illnesses, 38.4 million are caused by unknown agents and approximately 9.6 million of these illnesses are linked to 31 known pathogens. Of these known pathogens, Salmonella ranks among the top five pathogens responsible for ~90% of illnesses with known etiology. Shiga toxin‐producing Escherichia coli (STEC) and Salmonella are among those for which infection results in the most hospitalizations or deaths (2).

Evidence suggests pork is an important source of Salmonella infection and potentially an under‐ recognized source of STEC infections. Swine are known reservoirs (asymptomatic carriers and shedders) of Salmonella (3) and there are documented cases of Salmonella foodborne illnesses attributable to pork including those associated with outbreaks (3,4,5,6,7). Other studies show that swine harbor various serotypes of STEC including O157:H7 (8) and that STEC O157:H7 organisms are highly pathogenic in swine (9). Foodborne outbreaks caused by consumption of pork products contaminated with STEC

O157:H7 occurred in Canada in 2014 and 2018 (10,11); however, conclusive evidence of widespread pork‐associated STEC infections in the United States is limited.

To proactively guide policy decisions, FSIS reviews sampling data generated through its verification testing (1). Starting in 1996, with the PR/HACCP rule, market hog carcasses were periodically sampled and assessed under Salmonella performance standards. The very low frequency of positive results called into question whether sampling was warranted in this commodity. FSIS completed the Market

Hog Baseline Survey in 2011 to better ascertain Salmonella prevalence on market hog carcasses. The results of the study found that only an estimated 1.66% of market hog carcasses were positive for

Salmonella at post‐chill (12). This finding, in addition to years of verification testing data, supported

FSIS’ decision to suspend hog carcass sampling in 2012. However, one limitation of the Market Hog

Baseline Survey was that data on pathogen contamination in raw pork products was not collected.

In 2017, FSIS conducted a raw pork baseline study to obtain insight into pathogen contamination in processed pork products. The main objectives of the study were to characterize and determine prevalence of Salmonella in a variety of pork products and assess occurrence of STEC. Other objectives included assessing the relationship between pathogen presence and other factors such as indicator organisms and seasonality.

EXPERIMENTAL DESIGN AND PROCEDURES

Exploratory sampling (“Phase I”) was first conducted to obtain data to inform the design of the baseline study. In total, 1200 samples were randomly collected from federal slaughter and processing establishments that produced the categories of raw pork products described in Table 1, in addition to two minor “other” categories. Phase I samples were analyzed for Salmonella and indicator organisms

(generic E. coli, coliforms, Enterobacteriaceae, and aerobic counts), and a subset (200 total) were analyzed for the presence of STEC. Drawing upon what was learned in Phase I (13), the Raw Pork

Baseline Study was then initiated to obtain nationally representative data on raw pork products.

The baseline study was designed to reflect the entire federally inspected supply of raw pork products within the United States. Each federally inspected establishment that slaughter or fabricate pork products listed in the FSIS‐Public Health Information System (PHIS) database were identified, and each establishment’s average daily production volume was determined using data recorded into PHIS by inspection personnel (Tables 2A‐2C). Establishments included in the sampling frame included all federal establishments in the contiguous U.S. that produced eligible pork products and 1) had a daily average production volume of at least 101 pounds per day and 2) produced at least 21 days in a calendar month.

Eligible pork products in the baseline study included three product groups (comminuted, intact cuts, and non‐intact cuts) and were sampled using a stratified approach based on establishment production volume for each product group. Table 3 describes the frequency of sample collection for each stratum. Stratum boundaries were determined by applying the Visual Clustering method (14) to establishment production volume data. Sample allocation within each stratum was based on the percentage of samples positive for Salmonella in Phase I. The standard deviation of the percent positive values for Salmonella for each raw pork product group was calculated from the Phase I data and used to determine the estimated sample size needed for the baseline survey. Sample size calculation for comminuted products showed that 1680 samples would be enough to yield an 80% chance of detecting the pathogen. The sample size required for intact and non‐intact raw pork product groups were calculated in the same manner, resulting in 1260 for intact and 1248 for non‐intact cuts, respectively.

Therefore, the estimated number of samples for the survey was 4188. Establishments within the sampling frame were sampled for 12 months. To determine which antimicrobial interventions were applied during production of raw pork products, the Agency’s in‐plant inspection program personnel

(IPP) were asked to select from a dropdown menu or provide in free text, if known, the specific antimicrobial agent most recently applied to the product prior to sample collection.

All samples received in acceptable condition were analyzed for Salmonella and indicator organisms

(generic E. coli and aerobic counts). In a subset of samples, STEC testing was conducted; these samples were collected only from establishments that performed onsite slaughter and processing.Culture and characterization followed the procedures outlined in the FSIS Microbiology Laboratory Guidebook [MLG]

(15,16,17,18,19). Antibiotic susceptibility was done according to procedures developed by the National

Antimicrobial Resistance Monitoring System (NARMS) (20). Isolates were sequenced on the Illumina

MiSeq platform using standard laboratory procedures for Pulse Net Nextera XT library for the Illumina sequencer (21) and antibiotic resistance genetic markers responsible for the antibiotic resistance phenotype was determined using the U. S. National Library of Medicine, National Center for

Biotechnology Information Database Pathogen Browser in conjunction with the Antibiotic Resistance

Isolate Bank hosted by CDC and the Food and Drug Administration (22, 23).

Microbiological and other findings for each product group were summarized using descriptive statistics. The national prevalence or weighted average was calculated for Salmonella to provide a national average of expected values for Salmonella associated with raw pork products (24). The design of the study used class or “strata” by production volume. This design ensured that small plants were adequately represented despite their low production volume. Strata sampling introduces bias into sample collection and to counterbalance this bias, all establishments (from which samples were taken) were weighted by assigning each corresponding establishment’s fractional contribution to the total national production. Once weighted, the individual sample weight was calculated by taking shares in direct proportion to the number of samples taken from the establishment weight. The statistical software WesVar v 5.1 was used to calculate the national prevalence with confidence limits (24).

Levels of generic E. coli and AC were estimated using the most probable number (MPN) procedure and the results reported as MPN/gram. The MPN is used to estimate the population density of viable microorganisms in a test sample (19). The range of detectable indicator organisms for the samples was determined. To assess if there was a correlation between indicator organisms and Salmonella, the point biserial correlation coefficient (r) was calculated; this value measures the strength of co‐occurrence between indicator organisms and Salmonella as positive or negative. Ranges of r values are between plus and minus one; where ‐1 indicates a negative correlation and +1 indicates a positive correlation, and a value of zero indicates no correlation.

RESULTS

During the 12‐month period of the survey, 4232 samples were collected from a total of 285 establishments. Of the 4232 samples collected some were discarded because the sample integrity had been compromised resulting in 4145 tests samples analyzed. Some of the reasons samples were discarded include temperature of sample was too warm, incomplete paper work, sample held too long before shipping, packaging damaged during shipment, and package seal improperly placed.

Salmonella. Table 4 shows the breakdown of samples by product group, percent positive for

Salmonella, and national prevalence. Comminuted products showed the highest rate of Salmonella contamination at 22.0% (580 positives/4145 samples tested); this translated to a national prevalence of

26.70% (95% confidence interval 16.5% ‐ 36.99%). Of the 580 isolates recovered from positive samples, 53 distinct Salmonella serotypes were represented. The top five serotypes were Anatum at 13.6% (79 strains/580 positives) Infantis 12.8% (74 strains/580 positives), Johannesburg 9.0% (52 strains/590 positives), Derby 8.3% (48 strains/580 positives), and I 4,[5],12:i‐ 6.4% (37 strains/580 positives).

Sample collection spanned a full calendar year so that the number of samples collected during the colder months could be compared to the number of samples collected during the warmer months

(spring and summer). Recovery of Salmonella isolates did not show any discernible seasonal trend.

Antibiotic resistance among Salmonella Isolates. Of the 580 isolates associated with positive samples, 398 (68.6%) were pansusceptible, 92 (15.9%) were resistant to one or two antibiotic classes, and 90 (15.5%) were resistant to three or more antibiotic classes. Tables 5 shows the number of isolates associated with various resistance profiles by serotype. Several Salmonella isolates exhibited antibiotic resistance to antibiotics such as azithromycin and ceftriaxone, which are critically important for human medicine. In addition, other isolates exhibited resistance to other highly important antimicrobial drugs such as sulfamethoxazole/trimethoprim used to treat various types of gastrointestinal bacterial infections in humans.

All 37 isolates of Salmonella I 4, [5],12:i‐ carried antibiotic resistance markers and 81% of these strains had multiple drug resistance phenotypes. Further genomic analysis identified ciprofloxacin resistance qnrB2 and qnrB19 genes in Salmonella I 4,[5],12:i‐. Multiple Salmonella serotypes including I

4,[5],12:i‐ exhibited an intermediate resistance phenotype to ciprofloxacin (20) .

STEC. Of the 1474 samples analyzed for STEC, 3 (0.2%) were positive; two for E. coli O103 and one for E. coli O157. All positives were recovered from comminuted pork products. In addition to the confirmed positives, 400 samples screened positive for stx and eae genes but did not also confirm positive as any of the top 7 STEC serotypes currently analyzed by FSIS.

None of the STEC isolates were resistant to any of the antibiotics against which the strains were tested.

Source of raw pork product and Salmonella presence. Market hogs were the predominant swine class used to produce all three of the raw pork products. Market hogs comprised the largest percentage of source material in comminuted raw pork product samples at 47.0% [774 market hogs/1650 samples tested], and sows were the second largest at 24.0% [392 sows/1650 samples tested); the balance of 29% came from roaster pigs, feral hogs, boar, and/or stag [484 other swine class/1650 samples tested]. In addition, comminuted product made from sow material resulted in proportionately higher number of

Salmonella positive samples at 47% (170 positives from sow/361 positive samples) compared to comminuted products prepared from market hogs at 33.5% (121 positives from market hogs/361 positive samples). Comminuted raw pork products sourced from other swine classes resulted in 19% of samples positive for Salmonella (70 positives from other/361 positive samples).

Most of the intact (73.0% [949 from market hog/1296 samples]) and non‐intact (69.1% [829 from market hog/1199 samples]) raw pork samples came from market hogs and a small portion of intact (1%

[15 from sow/1296 samples]) and non‐intact cut (2.6% [31 from sow/1199 samples]) samples were from sow. The other swine classes made up a substantial portion of intact (26% [332 from other swine classes/1296 samples]) and non‐intact cuts (28.3% [339 from other swine classes/1199 samples]).

Salmonella contamination rates were also compared between slaughter and processing‐only establishments. Of the 2609 samples collected from processing‐only establishments, 260 (10.0%) were

Salmonella positive. A higher percent of positives was detected for samples collected from slaughter/processing establishments, with 320 out of 1536 (21.0%) samples positive.

Indicator organisms and correlation with pathogen presence. Table 6 shows the geometric mean for generic E. coli and AC for each product group. For comminuted products concurrence of Salmonella with Generic E. coli was determined by calculation of the biserial correlation coefficient which resulted in an r value = 0.072 (95% confidence intervals 0.024 to 0.12) with a p‐value of 0.0036, which suggests

Salmonella and presence of indicator were not correlated. Likewise, no correlation of Salmonella with aerobic count was apparent in comminuted products; the r value=0.0082 (95% confidence interval of ‐

0.04 to 0.056 with a p‐value of 0.74 which shows no strong correlation between the presence of aerobic count indicators and Salmonella. Similarly, there was no correlation between presence of generic E. coli or aerobic count indicators and Salmonella for intact and non‐intact cuts; in all cases the r value was not close to +1 which would indicate a positive correlation or ‐1 which would indicate a negative correlation.

Antimicrobial interventions and correlation with pathogen presence. In‐plant personnel who collected the samples were asked to list the antimicrobial applied most recently to the product prior to sample collection. Results shown in Table 7 indicate that essentially half (2052/4145 [49.5%]) of the samples collected were not treated with antimicrobial interventions by the establishment. When antimicrobial interventions were used, organic acids and peroxyacetic acid (PAA) mixtures were the most common choice (23%); 971 samples were treated with organic acids or peroxyacetic acid mixtures out of 4145 samples tested. Among samples that were Salmonella positive, 38% were treated with PAA and organic acids (222 Salmonella positive samples were treated/4145 samples tested). Other antimicrobial interventions such as acidified sodium chlorate, chlorine, and trisodium phosphate were used less frequently.

DISCUSSION

Pork is consumed in the United States as minimally processed whole muscle cuts and as processed raw products that are ground, cured, smoked or seasoned prior to distribution. In this study there was a relatively high prevalence of Salmonella in comminuted products, which is important given that sausage as well as ham and bacon are among the pork products most commonly consumed in the United States

(25). The results suggest steps in the processing of raw pork into comminuted products allows pathogens to survive or grow despite widespread usage of antimicrobial interventions.

Fabrication and grinding of meat used in the production of comminuted products could allow contamination present in the source materials to spread throughout the product. In addition, certain source materials used in comminuted products, such as pork derived the feet, jowls, or hindquarter portions, may be significant contributors of bacterial contamination. Studies suggest that comminuted pork might also contain lymphatic material and synovial fluid derived from stripping of meat from bones

(26), which could increase Salmonella contamination. Understanding the pathogen risks associated with procedures used in slaughter and processing is essential for mitigation strategies.

Aerobic counts have been suggested as reliable indicator organisms because the magnitude of aerobic bacterial counts is highest on meat products and estimation of the most probable number

(MPN) per gram of sample is reliable (27). Typically, generic E. coli occur within the gastrointestinal tract of animals at low levels, consequently if present on meat products the failure rate of detecting these low number of generic E. coli would be high (27). In this study, AC and generic E. coli were present in all the raw pork product groups. However, the data indicates that the presence of aerobic counts and generic

E. coli are not correlated so these indicators may not be good predictors of foodborne pathogens like

Salmonella.

The results indicate that pork‐associated Salmonella had characteristics in common with

Salmonella in humans. Serotypes that have been associated with foodborne outbreaks, such as

Salmonella Newport, were among those isolated from samples collected in this study. In addition, a substantial fraction of Salmonella isolates recovered belong to serotypes known to cause sporadic human illness. Serotypes Anatum, Infantis, and I 4,[5],12:i‐, which together accounted for 32.8% of all

Salmonella isolates in the study, are in the top 20 most frequently reported Salmonella serotypes causing illness in the United States (7).

Of the 580 Salmonella strains recovered, 31% (182 Salmonella strains were antibiotic resistant/580 strains recovered) carried antibiotic resistance markers. Importantly, all the S. I 4,[5],12:i‐ isolates recovered carried antibiotic resistance genes, with 86% of them carrying multiple antibiotic resistant genes. Most of the antibiotic resistance genes carried by S. I 4,[5],12:i‐ were antibiotics used in treatment of human infections. This finding is important because S. I 4,[5],12:i‐ ranks 5th as one of the most frequently reported serotypes linked to human illness (4). Treatment of persons at risk of invasive

Salmonella infections require antibiotics such as trimethoprim/sulfamethoxazole (28) and when these are not effective, a second line antibiotic may include ceftriaxone (29). In addition, carriage of antibiotic resistance genes on mobile elements are also important because these markers can be transmitted to susceptible bacterial species even if the antibiotic resistance genes are not expressed in the original bacterial cell. FSIS, in collaboration with the United States Food and Drug Administration (FDA) and CDC, tracks antibiotic resistance in food animal isolates recovered from FSIS regulatory products. Ongoing work to study the genetic composition of pathogens recovered from food products and the genetic‐ relatedness of these isolates to those recovered from foodborne outbreaks will increase the understanding of how these pathogens persist in food animals and how they survive during slaughter and processing intervention procedures.

Detectable levels of STEC in raw pork suggests that pork consumption provides a potential avenue for human infection. However, the low frequency at which STEC was recovered, combined with limited epidemiologic evidence that pork‐associated infections are a common occurrence, supports the view that this pathogen may not be a major food safety concern in this commodity. Several of the raw pork samples screened positive for stx and eae genes but did not confirm positive for any of the top 7 STEC currently analyzed by FSIS. It is possible that a screen positive for stx and eae were caused by the presence of one or more of the 50 other serotypes of E. coli that carry the stx and eae genes. These

STEC are known causes of human disease (30), although to a lesser extent than the 7 serotypes that FSIS classifies as adulterants. The E. coli O157:H7 outbreak that occurred in Canada in 2018, which was linked to comminuted and intact cuts of pork (31), underscores the need for the continued monitoring of public health trends. Additional research is needed to understand the full range of STEC serotypes present in raw pork products (32).

CONCLUSIONS

Findings from the Raw Pork Baseline Study show that Salmonella in raw pork merits policy consideration. The relatively high rates of Salmonella observed in this study indicate that, in contrast to what was observed in the past with hog carcasses, performance standards focused on processed pork might provide a meaningful measure of process control. Furthermore, the serotypes and antibiotic resistance profiles seen in pork‐associated Salmonella appear relevant to public health. With respect to

STEC, additional research is needed to understand the full range of STEC serotypes present in raw pork products and pork’s contribution the human STEC infections (32).

ACKNOWLEDGEMENTS

The authors recognize the many FSIS individuals responsible for making a baseline study like the Raw

Pork Product Sampling Program successful. Working together daunting tasks become doable. A special recognition goes to the Office of Field Operations/Inspection Program Personnel and those at

Headquarters (HQ); Office of Public Health Science/Field Service Laboratories and HQ staff; Office of

Policy and Program Development; as well as the Office of Planning, Analysis, and Risk Management and others who helped steer the study in the right direction.

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FOOTNOTES

TABLE 2A

1The total number of establishments eligible for sampling in each stratum includes both slaughter and processing‐only plants.

2 PR stands for processing establishments and SL stands for slaughter establishments.

3The total number of establishments = 1747 that produce comminuted pork products for a total of

197,159,000 lbs./month. The eligible sampling frame = total # of establishments minus ineligible establishments resulted in 193,999,000 lbs./month. This represents 98.4% of the U.S. market for comminuted pork. Elimination of ineligible plants resulted in 253 in the sampling frame.

3 The monthly production total shown on the table represents elimination of small plants that produce less than 10,000 lbs. per month and plants not located within the contiguous continent of the U.S.

TABLE 2B

1The total number of establishments eligible for sampling in each stratum includes both slaughter and processing‐only plants.

2PR stands for processing‐only establishments and SL stands for slaughter establishments

3 The total number of establishments = 1412 establishments produced intact pork cuts for a total of

223,128,500 pounds per month. The eligible sampling frame = total establishments minus ineligible establishments resulted in 220,243,500 pounds produced per month; representing 98.7% of the U.S.

market for intact pork cuts production. Elimination of plants not eligible to be included in the sampling frame resulted in 178 plants remaining.

4 The monthly production total shown on the table represents elimination of small plants that produce less than 10,000 lbs. per month and plants not located within the contiguous continent of the U.S.

TABLE 2C

1There are only two strata in the non‐intact raw pork product category.

2 Number of establishments within each stratum contains both slaughter and processing‐only plants.

The PHIS database listed 157 establishments producing non‐intact pork cuts with a total of 89,066,000 lbs. per month. Removal of ineligible plants resulted in a total of 45 establishments producing

88,782,500 lbs. per month of non‐intact pork cuts. This represents 99.7% of the entire U.S. market that produced non‐intact raw pork products.

3 PR stands for processing‐only establishments and SL stands for slaughter‐processing establishments.

TABLE 3

1Strata = Total volume of product in pounds produced by establishment per month.

2Number of eligible establishments = the total number of establishments which fall within the 3 specific strata.

3Number of establishments included in the sampling frame, includes both processing and slaughter.

4The monthly sampling frequency per establishment for each stratum is based on the design of the baseline study.

5The total number of samples to be collected per stratum = frequency per year x number of establishments in sample‐frame per strata.

TABLE 5

1Salmonella serotypes isolated during Phase II of the study that were all pan‐susceptible:

Amsterdam_var._15+,34+ (2); Anatum_var._15+ (1); Barranquilla (1); Berta (4); Cannstatt (2); Cerro (1);

Eko (12); Enteritidis (1); Give (2); Goldcoast (2); Havana (1); Krefeld (2); Litchfield (1); Liverpool (1);

Manhattan (4); Montevideo (5); Muenster (4); Orion (1); Orion_var_15+ (3); Panama (2); Rough_O:z:lw

(1); Ruiru (1); Soerenga (6).

2Numbers in parenthesis refer to number of isolates.

3 AUG = Amoxicillin/Clavulanic Acid, AMP = Ampicillin, AZI = Azithromycin, FOX = Cefoxitin, CFU =

Ceftiofur, AXO = Ceftriaxone, CIP = Ciprofloxacin, GEN = Gentamicin, NAL = Nalidixic Acid, STR =

Streptomycin, SXZ = Sulfisoxazole, COT = Trimethoprim‐sulfamethoxazole, CHL = Chloramphenicol, and

TET = Tetracycline

Note: The isolates with intermediate antibiotic resistance phenotypes against ciprofloxacin are not shown because these isolates technically are not considered resistant but form a new subcategory called

“decreased susceptibility to ciprofloxacin (DSC) (20).

TABLE 7

1The other category means that if an antimicrobial intervention was used it was not available for selection.

Table 1: Eligible Raw Pork Products

Product Group

Product subgroup

Description of the Raw pork product categories

Intact Cuts Bone‐in and boneless

Food service cuts from primal cuts, portion cuts, or try‐ready cuts prepared for consumers that have not been subjected to processing that renders the product non‐intact (e.g. needle or blade tenderized, injected, pumped or vacuum tumbled).

Non‐Intact cuts

Bone‐in and boneless

Food service cuts from primal cuts, portion cuts, or tray—ready cuts prepared for consumers that have been subjected to processing that renders the product non‐intact (e.g. needle or blade tenderized, injected, pumped or vacuum tumbled).

Ground product Pork product that is run through a grinding system designed to reduce the size of muscle pieces.

Mechanically separated

Finely textured pork products resulting from mechanical separation and removal of most of the bone from attached skeletal muscle that does not qualify as “pork” per 9 CFR 318.24 and 319.5.

Comminuted Advanced Meat recovery (AMR), products

Finely comminuted pork product resulting from mechanical separation and removal of all bone from attached skeletal muscle.

Sausage, patties, or other formed products are comminuted

Raw pork products that were formed out of comminuted pork

Additional Comminuted

Pork product with a reduced particle size from any other process (e.g.

coarse chopped pork)

Table 2A. Strata for Establishments Producing Comminuted Raw Pork Products

Stratum 1,2Number of Establishments

(PR)(SL)

3Monthly Production

% Production in United States Market

1 25 149,350,000 77.0%

PR (9) 57,250,000 29.5%

SL (16) 92,100,000 47.5%

2 99 40,565,000 20.9%

PR (77) 30,302,500 15.6%

SL (22) 10,262,500 5.3%

3 129 4,075,000 2.1%

PR (114) 3,675,500 1.9%

SL (15) 399,500 0.2%

Total 253 193,990,000 100%

Table 2B. Strata for Establishments Producing Intact Cuts of Raw Pork Products

Stratum 1Number of Establishments

2 (PR)(SL)

Monthly Production

Percent Production United States Market

1 20 200,950,000 91.2%

PR (9) 64,300,000 29.2

SL (11) 136,650,000 62.0

2 45 16,290,500 7.4%

PR (39) 14,053,000 6.4%

SL (6) 2,237,500 1.0%

3 113 3,003,000 1.4%

PR (87) 2,357,500 1.1%

SL (26) 646,000 0.3%

Total 3178 4220,243,500 100%

Table 2C. Strata for Establishments Non‐Intact Raw Pork Products

1Stratum 2Number of Establishments

3(PR)(SL)

Monthly Production

% Production in United States Market

1 9 79,575,000 89.6%

PR (7) 56,625,000 63.8%

SL (2) 22,950,000 25.8%

2 36 9,207,500 10.4%

PR (27) 6,341,500 7.1%

SL (9) 2,866,000 3.2%

Total 45 88,782,500 100%

Table 3: Sample Allocation for Raw Pork Product Groups Used

1Strata

2Number Eligible Establishments

3Establishments in Sampling

Frame

Percent of Total Eligible Establishments

Selected

4Sampling Frequency

Each month

Samples Per Establishment Each Year

5Total Samples Collected For each Stratum

Comminuted Pork Products

≥1,000,000 lbs. 25 25 100.00% 2 24 600

>90,000 up to 1,000,000 lbs. 99 50 50.50% 1 12 600

>10,000 up to 90,000 lbs. 129 80 62.00% 0.5 6 480

Total 253 155 61.20% 1680

Intact Pork Cuts

≥1,000,000 lbs. 20 20 100.00% 2 24 480

>90,000 up to 1,000,000 lbs. 45 20 44.40% 1 12 240

>10,000 up to 90,000 lbs. 113 90 79.60% 0.5 6 540

Total 178 130 73.00% 1260

Non‐Intact Pork Cuts

≥1,000,000) 9 9 100.00% 4 48 432

<1,000,000 ‐ >10,000) 36 34 94.40% 2 24 816

Total 45 43 95.50% 1248

Total Samples Scheduled for Phase II

Table 4: Baseline Study Results for Salmonella

Product Samples Analyzed Percent Positive National prevalence

Confidence Interval

Comminuted 1,650 361(22.0%) 27.0% 16.5% ‐ 37.0%

Intact 1,296 129 (10.0 %) 10.0% 2.5% ‐ 17.6%

Non‐intact 1,199 90 (7.5%) 6.0% 1.2% ‐ 11.0%

Total 4,145 580 (14.0%)

Table 5: Antibiotic Resistance Phenotypes of Salmonella 1Isolates Recovered in Phase II

2Salmonella Serovars Phase II

Total # of Isolates Susceptible 3Antibiotic Resistance

Adelaide (14) 13 NAL STR SXZ TET (1)

Agona (15) 9

AUG AMP FOX AXO CHL GEN STR SXZ TET (2); AUG AMP FOX AXO CHL STR SXZ TET (1);

AUG AMP FOX AXO STR TET (1); SXZ TET (1); TET (1)

Anatum (79) 57 AUG AMP FOX AXO (1); AZI (1); NAL TET (2); TET (18)

Bovismorbificans (6) 4 TET (2)

Braenderup (4) 3 TET (1)

Brandenburg (15) 9 AMP TET (2); GEN STR SXZ TET (1); NAL (2); NAL SXZ TET (1)

Bredeney (2) 0 AMP NAL STR TET (1); STR TET (1)

Chailey (3) 2 TET (1)

Derby (48) 9

AMP AXO CHL NAL STR SXZ TET (2); AMP STR SXZ TET (1); AUG AMP FOX AXO STR SXZ

TET (2); CHL STR SXZ TET (1); CHL TET (1); STR SXZ TET (16); TET (16)

Hadar (1) 0 STR TET (1)

Heidelberg (5) 0

AMP AXO GEN NAL STR SXZ TET COT (1); AMP AXO STR SXZ TET COT (1); AUG AMP FOX

AXO NAL STR SXZ TET COT (1); STR TET (2)

I 4,[5],12:i:‐ (37) 0

AMP AXO CHL GEN SXZ (1); AMP AXO CHL STR SXZ TET (1); AMP CHL GEN SXZ COT (1);

AMP GEN STR SXZ TET (1); AMP NAL STR SXZ TET (3); AMP STR SXZ TET (15); AUG AMP

FOX AXO CHL GEN STR SXZ TET COT (1); AUG AMP FOX AXO TET (1); CHL SXZ COT (1); CHL

STR SXZ TET (1); CHL TET (1); GEN STR SXZ TET (3); NAL (1); TET (6)

Infantis (74) 69 AMP AXO CHL GEN SXZ TET (1); CHL NAL (1); CHL NAL SXZ TET (1); NAL (1); TET (1)

Johannesburg (52) 43 AMP AZI CHL NAL SXZ TET (1); AMP SXZ TET (1); AMP GEN NAL STR SXZ TET (1); NAL SXZ

TET (1); STR SXZ TET (1); TET (4)

Kentucky (1) 0 STR TET (1) Livingstone (2) 1 AUG AMP FOX AXO CHL STR SXZ TET (1)

London (26) 21 AMP STR SXZ COT (1); AUG AMP FOX AXO STR TET (1); CHL STR SXZ TET (1); TET (2)

Mbandaka (7) 6 SXZ COT (1)

Muenchen (9) 8 SXZ TET (1)

Ohio (32) 28

AUG AMP FOX AXO (1); AUG AMP FOX AXO CHL NAL STR SXZ TET COT (1); FOX (1); TET

(1)

Orion_var._15+,34+ (1) 0 STR TET (1)

Reading (8) 6 TET (2)

Rissen (6) 2 NAL TET (1); STR SXZ TET (1); TET (2)

Rough_O:fg:‐ (1) 0 NAL (1)

Saintpaul (5) 4 TET (1)

Schwarzengrund (8) 6 STR (2)

Senftenberg (5) 4 AMP AZI CHL GEN SXZ TET COT (1)

Typhimurium (14) 3 AMP CHL NAL STR SXZ TET COT (1); AMP CHL STR SXZ TET (5); AMP SXZ (1); AMP STR SXZ

TET (2); AUG AMP FOX AXO GEN STR SXZ TET (1); TET (1)

Uganda (24) 22 STR SXZ TET (2)

Worthington (14) 9 AUG AMP FOX AXO (1); TET (4)

Table 6: Estimate of Indicator Organisms Associated with Raw Pork Products

Indicator Organisms

Pork Product

Enumeration Estimates

Arithmetic Mean MPN/gram

Geometric Mean

Geometric Mean (Log 10)

Standard Deviation of the mean (Log 10)

Aerobic Count Comminuted 1642 92425.69 607.59 2.78 1.13

Intact Cuts 1291 67492.29 286.64 2.46 1.08

Non‐Intact Cuts 1196 23567.77 245.79 2.39 0.99

Generic E. coli Comminuted 1644 426.94 48.48 1.69 0.35

Intact Cuts 1291 429.18 43.24 1.64 0.23

Non‐Intact Cuts 1196 49.14 41.33 1.62 0.12

Table 7. Antimicrobials Used to Treat Raw Pork Products During Fabrication and Number of

Salmonella Isolates Recovered

Product

Antimicrobial Applied

Total Number of Samples

Salmonella Positives

Comminuted

Total Comminuted 1650 361

No antimicrobial agent 835 134

Acidified sodium chlorite 7 0

Chlorine 51 19

Hypobromous acid 1 0

Organic Acids (e.g., lactic, acetic, and citric acid) 340 100

Peroxyacetic acid (PAA) mixtures 120 37

Sodium hypochlorite 9 3

Trisodium phosphate 0 0 1Other 287 68

Intact Cuts

Total Intact Cuts 1296 129

No antimicrobial agent 656 49

Acidified sodium chlorite 0 0

Chlorine 27 2

Hypobromous acid 1 0

Organic Acids (e.g., lactic, acetic, and citric acid) 163 32

Peroxyacetic acid (PAA) mixtures 158 33

Sodium hypochlorite 11 0

Trisodium phosphate 4 0

Other 276 13

Non‐Intact Cuts

Total Non‐Intact Cuts 1199 90

No antimicrobial agent 561 33

Acidified sodium chlorite 0 0

Chlorine 5 0

Organic Acids (e.g., lactic, acetic, and citric acid) 100 6

Peroxyacetic acid (PAA) mixtures 90 14

Sodium hypochlorite 13 1

Trisodium phosphate 31 1

Other 399 35

Total 4145 580