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Foodborne salmonellosis is commonly associated with poultry and poultry products, necessitating continued development of pre- and postharvest food safety interventions and risk management strategies. Evaluation of technologies and strategies is limited by availability of cost-effective, rapid laboratory methods. The objective of this study was to evaluate a commercial qualitative PCR assay and its novel quantitative application to detect and enumerate Salmonellain poultry ceca as an analytical matrix. Ceca were collected at harvest, the contents were homogenized, and paired samples were evaluated with buffered peptone water (BPW) and BAX MP + Supplement (MPS) preenrichment broths followed by PCR screening with a BAX System Q7 PCR and by culture isolation. Additional ceca were inoculated with Salmonellato develop a standard curve for the BAX System SalQuant quantitative PCR application (QA), and estimates were obtained by the QA and most-probable-number (MPN) methods. For preenrichment media, PCR outcomes were equivalent to those of culture isolation for detecting Salmonellain ceca with 95.65 and 87.88% sensitivity and 82.00 and 100.00% specificity (P= 0.074) for BPW and MPS, respectively. However, at the sample level, BPW performed significantly worse (47.92%) than did MPS (68.75%) for overall isolation of Salmonella(P< 0.0001). After standard curve development, the mean QA estimates obtained for the inoculated samples were 1.14 (95% confidence interval [CI]: 0.62 to 1.66), 1.79 (1.50 to 2.08), 2.91 (2.65 to 3.17), and 3.76 (3.26 to 4.25) log CFU/mL for each targeted inoculation of 1.0, 2.0, 3.0, and 4.0 log CFU/mL, respectively, and were within or comparable to the 95% CI values of paired MPN estimates. These data support the use of MPS for the detection and isolation of Salmonella entericafrom poultry ceca when screening with PCR and indicate that QA may be useful as an alternative tool to estimate Salmonellaloads in poultry ceca, which may support preharvest food safety interventions.

•Salmonellaprevalence was 36% for tonsils and 35% for mesenteric lymph nodes.•Salmonellaprevalence was less than 10% for all other lymph node types.•Salmonellaprevalence and concentration varied by region and season.

Chicken carcass and parts rinsate samples and fecal samples were collected at different stages in a commercial poultry processing facility. Microbiological analysis was conducted to determine the levels of multiple indicator microorganisms and prevalence of Salmonella. Antibiotic susceptibility testing was conducted on Salmonellaisolates to determine antimicrobial resistance profiles. Whole genome sequencing was performed for tracing isolates in the processing chain, serotyping, and determining genetic features associated with virulence and antimicrobial resistance in the bacterial genome. The overall contamination rate was 55% for Salmonella. Prevalence increased by 80% in chicken parts compared with the previous processing site (postchill carcasses), suggesting possible cross-contamination during the cutting and deboning processes. The levels of indicator organisms were reduced significantly from the prescalding to the parts processing sites, by 3.22 log CFU/mL for aerobic plate count, 3.92 log CFU/mL for E. coli,3.70 log CFU/mL for coliforms, and 3.40 log CFU/mL for Enterobacteriaceae. The most frequent resistance in Salmonellawas associated with tetracycline (49 of 50, 98%) and streptomycin (43 of 50, 86%). Some Salmonellaisolates featured resistance to the cephems class of antibiotics (up to 15%). Whole genome sequencing analysis of Salmonellaisolates identified nine different clonal populations distributed throughout the samples taken at different stages; serotype Kentucky was the most commonly isolated. This study provides insights into microbial profiling and antibiotic-resistant strains of chicken rinsate samples during poultry processing.

The poultry processing industry has been undergoing a series of changes as it modifies processing practices to comply with new performance standards for chicken parts and comminuted poultry products. The regulatory approach encourages the use of intervention strategies to prevent and control foodborne pathogens in poultry products and thus improve food safety and protect human health. The present studies were conducted to evaluate the efficacy of antimicrobial interventions for reducing Salmonellaon inoculated chicken parts under simulated commercial processing conditions. Chicken pieces were inoculated by immersion in a five-strain Salmonellacocktail at 6 log CFU/mL and then treated with organic acids and oxidizing agents on a commercial rinsing conveyor belt. The efficacy of spraying with six different treatments (sterile water, lactic acid, acetic acid, buffered lactic acid, acetic acid in combination with lactic acid, and peracetic acid) at two concentrations was evaluated on skin-on and skin-off chicken thighs at three application temperatures. Skinless chicken breasts were used to evaluate the antimicrobial efficacy of lactic acid and peracetic acid. The color stability of treated and untreated chicken parts was assessed after the acid interventions. The lactic acid and buffered lactic acid treatments produced the greatest reductions in Salmonellacounts. Significant differences between the control and water treatments were identified for 5.11% lactic acid and 5.85% buffered lactic acid in both skin-on and skin-off chicken thighs. No significant effect of treatment temperature for skin-on chicken thighs was found. Lactic acid and peracetic acid were effective agents for eluting Salmonellacells attached to chicken breasts.

Thermal inactivation of Salmonellais a critical component of the calculated thermal process to ensure the safety of cooked human and animal products. However, lethality performance standards for meat processing by-products that may harbor Salmonellahave not been properly set under the actual conditions of rendering processes. The goal of this study was to evaluate the thermal inactivation parameters for Salmonellain high-fat beef trimmings as a model system for animal food products treated under simulated “worst-case scenario” commercial rendering conditions. Ground high-fat beef trimmings (50% fat) were artificially inoculated with a 108CFU/g Salmonellacocktail containing human outbreak strains including the highly thermotolerant serotype SalmonellaSenftenberg. The meat samples were packaged and immersed in either water or silicon oil at predetermined temperatures ranging from 60 to 121°C (from 140 to 250°F). D-values of Salmonellaat each temperature were calculated from the negative inverse slope of the log CFU per gram versus time plot. The z-values were determined from the negative inverse slope of the log Dversus temperature plot. The D-values in thermal death curves for low-fat (20%) content materials (between 60 and 95°C) were 2.175, 0.658, 0.237, 1.563, 0.356, 0.284, 0.264, and 0.201 min, whereas materials with 50% fat (between 100 to 121°C) were 0.277, 0.286, 0.159, 0.143, 0.137, and 0.087 min. The z-values for low- and high-temperature schedules were 43.7 and 42.9°C, respectively. Thermal lethality data for Salmonellainactivation in high-fat rendering raw materials will help animal food processors design adequate thermal processing schedules and support critical control points to ensure the safety of final beef-based rendered products.

Salmonellacontamination continues to be one of the major concerns for the microbiological safety of raw poultry products. Application of more than one decontamination agent as a multihurdle intervention to carcasses in a processing line might produce greater reductions than one treatment alone due to different modes of action of individual antimicrobials. In this study, all possible two-way combinations and individual applications of ε-polylysine (EPL), lauric arginate (LAE), and acidic calcium sulfate (ACS) solutions were evaluated for their effects against Salmonella entericaserovars, including Enteritidis and Typhimurium, using a sterile membrane filter model system. The combinations that provided higher Salmonellareductions were further evaluated on inoculated chicken carcasses in various concentrations applied in a sequential manner. Sequential spray applications of 300 mg of EPL per liter followed by 30% ACS and of 200 mg of LAE per liter followed by 30% ACS produced the highest Salmonellareductions on inoculated chicken carcasses, by 2.1 and 2.2 log CFU/ml, respectively. Our results indicated that these sequential spray applications of decontamination agents are effective for decreasing Salmonellacontamination on poultry carcasses, but further studies are needed to determine the effectiveness of these combinations over a storage period.