ABSTRACT The Agricultural Marketing Service procures boneless and ground beef for federal nutrition assistance programs. It tests procured beef for concentrations of standard plate counts (SPCs), coliforms, and Escherichia coli and for the presence of Salmonella and Shiga toxin–producing E. coli . Any lot exceeding predefined critical limits (100,000 CFU g −1 for SPCs, 1,000 CFU g −1 for coliforms, and 500 CFU g −1 for E. coli ) or positive for Salmonella or Shiga toxin–producing E. coli is rejected for purchase. Between 1 October 2013 and 31 July 2017, 166,796 boneless beef lots (each approximately 900 kg) and 25,051 ground beef sublots (each approximately 4,500 kg) were produced. Salmonella was detected in 1,955 (1.17%) boneless beef lots and 219 (0.87%) ground beef sublots. Salmonella sample size increased from an individual 25-g sample to a co-enriched 325-g sample on 1 March 2015. Salmonella presence was associated with season (lowest in spring), larger sample size, and increased log SPC in boneless and ground beef. Increased log E. coli was associated with Salmonella presence in boneless beef, but not ground beef. Salmonella Dublin was the most common serotype in boneless beef (743 of 1,407, 52.8%) and ground beef (35 of 171, 20.5%). Salmonella Dublin was generally associated with lower indicator microorganism concentrations compared with other Salmonella serotypes as a group. Relative to other Salmonella, Salmonella Dublin was associated with season (more common in spring) and smaller sample size in boneless and ground beef. Decreased log SPCs and log coliforms were associated with Salmonella Dublin presence in boneless beef, but not in ground beef. Differential associations between Salmonella Dublin and other serotypes with indicator microorganisms were strong enough to cause confounding and suggest that the presence of Salmonella Dublin needs to be accounted for when evaluating indicator performance to assess Salmonella risk in boneless and ground beef. HIGHLIGHTS Salmonella was associated with indicator microorganism detection and concentration. Salmonella Dublin represented 52.8% of Salmonella in boneless and 20.5% in ground beef. Salmonella Dublin was associated with lower indicator levels compared with other Salmonella .
ABSTRACT The Agricultural Marketing Service (AMS) purchases beef for the National School Lunch Program and other federal nutrition assistance programs. For beef that will be delivered to food service facilities raw, each ca. 900-kg lot of boneless beef raw material and each ca. 4,500-kg sublot of resultant ground beef is tested for standard plate count (SPC) organisms, coliforms, Escherichia coli, Salmonella, and E. coli O157:H7. In addition, 1 of every 10 lots of boneless beef, randomly selected, is tested for E. coli O26, O45, O103, O111, O121, and O145. For beef that will be cooked using a validated lethality step at a federally inspected establishment before delivery, each lot of boneless beef and each sublot of ground beef is tested for SPC organisms, coliforms, and E. coli only. Any lot or sublot exceeding predefined critical limits (CLs) of 100,000 CFU g −1 for SPC organisms, 1,000 CFU g −1 for coliforms, or 500 CFU g −1 for E. coli or for beef containing Salmonella or any of previously mentioned E. coli serotypes is rejected for purchase. For school years 2015 through 2018 (July 2014 through June 2018), 220,497,254 kg of boneless beef and 189,347,318 kg of ground beef were produced for AMS. For boneless beef, 133 (0.06%), 164 (0.07%), and 106 (0.04%) of 240,488 lots exceeded CLs for SPC organisms, coliforms, and E. coli, respectively; 2,038 (1.30%) and 116 (0.07%) of 156,671 lots were positive for Salmonella and E. coli O157:H7, respectively; and 59 (0.36%) of 16,515 lots were positive for non-O157 Shiga toxin–producing E. coli . For ground beef, 46 (0.10%), 27 (0.06%), and 19 (0.04%) of 45,769 sublots exceeded CLs for SPC organisms, coliforms, and E. coli, respectively; and 329 (1.40%) and 18 (0.08%) of 23,475 sublots were positive for Salmonella and E. coli O157:H7, respectively. All lots and sublots found to exceed indicator organism CLs or to contain pathogens were identified, rejected for purchase, and diverted from federal nutrition assistance programs. HIGHLIGHTS AMS purchases beef for the National School Lunch Program. Less than 0.10% of beef samples exceeded indicator organism critical limits. Salmonella was found in 1.4% and E. coli O157:H7 was found in 0.08% of samples. Indicator critical limit exceedance was weakly associated with pathogen presence. Beef with excessive indicator organisms or containing pathogens was rejected for purchase.