Carcass Rinse Research Articles

Campylobacter Diversity Along the Farm-to-Fork Continuum of Pastured Poultry Flocks in the Southeastern United States.

Consumer demand for pasture raised, antibiotic-free poultry products has led to an increase in pastured poultry operations within the United States. Given the level of environmental interaction and the potential increase in exposure to foodborne pathogens in these settings, a greater understanding of the prevalence and diversity of Campylobacter populations inherent within pastured poultry flocks is needed. To achieve this, 40 pastured poultry flocks from nine farms were sampled using a farm-to-fork strategy, and Campylobacter was isolated and characterised from preharvest (faeces, soil) through postharvest (caeca, whole carcass rinse) to the final product the consumer would purchase (whole carcass rinse). Campylobacter was isolated from 872 of 1820 samples, showing an overall prevalence of 47.91%. The caeca showed the highest (p < 0.05) Campylobacter load (4.64 log10 CFU/mL) and prevalence (95.5%), while the final product whole carcass rinses had the lowest (p < 0.05) Campylobacter load (0.32 log10 CFU/mL) and prevalence (15.45%), suggesting that the Campylobacter load in the caeca may not be indicative of the Campylobacter load on the final product. Of the 872 positive samples, 337 Campylobacter isolates were selected for further characterisation. Campylobacter jejuni and Campylobacter coli comprised 74.18% (250/337) and 21.95% (74/337) of the selected isolates respectively. While the Campylobacter isolates displayed resistance to several antibiotics, the most common resistance for both C. jejuni and C. coli was against tetracycline (55.86% and 70.31% respectively). Multidrug resistance phenotypes (≥ 3 antibiotic classes) were relatively low for both C. jejuni (2.80%) and C. coli (9.45%). Campylobacter load, prevalence and diversity were more affected by farm location than by the type of sample from which the Campylobacter was isolated. Overall, these results indicated a need for farm-specific Campylobacter mitigation strategies to ensure the safety of these increasingly in-demand poultry products.

Targeted Next-Generation Sequencing Assay for Direct Detection and Serotyping of Salmonella from Enrichment

In this study, an automated, targeted next-generation sequencing (tNGS) assay to detect and serotype Salmonella from sample enrichments was evaluated. The assay generates millions of reads to detect multiple Salmonella-specific genes and serotype-specific alleles, detecting all Salmonella spp. tested to date, and serotyping 62 common Salmonella serotypes. Accuracy was tested on 291 pure reference cultures (251 Salmonella, 40 non-Salmonella), 21 artificially contaminated poultry carcass rinse samples, and 363 naturally contaminated poultry environmental samples. Among the 291 pure reference cultures, the automated tNGS assay resulted in 100% detection accuracy, 100% serotyping accuracy for the claimed serotypes, and 0% false positives. The limit of detection was estimated at 5 × 104 CFU/mL by testing enumerated cultures of strains representative of six serotypes. In cocontamination studies with mixtures of two serotypes (Enteritidis, Typhimurium, Kentucky, Infantis, and Newport) at a 1:1 ratio, tNGS detected both serotypes with 100% accuracy. The assay demonstrated 100% accuracy in artificially contaminated poultry carcass rinse sample enrichments. Targeted NGS was highly effective in detecting Salmonella in samples collected from poultry production facilities. Results demonstrated that tNGS could detect Salmonella and provide accurate serotyping information consistent with conventional serology. These findings highlight the reliable and efficient performance of a fully automated tNGS Salmonella assay in detecting and identifying Salmonella strains in complex matrices, reducing the time to results from 4 to 5 days required by the traditional isolation and serotyping to 10–12 h for tNGS after primary enrichment.

Addressing Current Challenges in Poultry Meat Safety: Development of a Cultivation and Colony Hybridization Approach to Recover Enterotoxigenic Clostridium perfringens from Broiler Chicken Carcasses.

Enterotoxigenic Clostridium perfringens is one of the main causes of foodborne illness in Canada. The use of a conventional bacterial culture approach to isolate enterotoxigenic C. perfringens from poultry meat is common. This approach is based on the phenotype attributable to a double hemolysis phenomenon, whereas few enterotoxigenic strains of C. perfringens produce it, which further complicates the study of the reservoirs of this important pathogen. The objectives of the current study were to validate the ability of a digoxigenin-labeled probe to detect the C. perfringens cpe gene and to validate the use of either a filtration or a direct plating approach, combined with colony hybridization to detect enterotoxigenic C. perfringens. Pure DNA and pure colonies of enterotoxigenic C. perfringens and broiler chicken carcass rinsate samples were subjected to colony hybridization. The results showed that the synthesized DNA probe can detect the cpe gene from both DNA and pure colonies of enterotoxigenic C. perfringens, and from colonies grown from carcass rinsates artificially contaminated with enterotoxigenic C. perfringens. Our study suggests that this isolation method is a promising tool for a better understanding of the epidemiology of this zoonotic pathogen.

Microbiome Analysis of Organic and Conventional Chickens Processed Using Whole Carcass Enrichment and Rinse Methods

Investigating the chicken microbiome is important to establish control measures for pathogens to protect consumers. This study aimed at evaluating the comparative efficiency of human pathogen detection through 16S rRNA sequencing of organic and conventional chickens processed using whole carcass enrichment (WCE) and rinse (WCR) methods. Organic and conventional whole broiler carcasses (n = 31) were vigorously shaken with 500 mL buffered peptone water (BPW). For the rinse method, a 30 mL aliquot was mixed with 30 mL of BPW. The rest of the sample, including the carcass, was used for the enrichment method. All samples were incubated at 37°C for 24 h. The samples were divided into five groups [Negative Control: only BPW without chicken (n = 5), Organic-Rinsed (n = 7), -Enriched (n = 8), Conventional-Rinsed (n = 7), and -Enriched (n = 9)]. Fifty milliliters of each sample were subjected to DNA extraction followed by 16S rRNA sequencing. Proteobacteria and Firmicutes predominated the microbiota of both conventional and organic chickens, followed by low abundances of Bacteroidetes and Fusobacterium. While the abundance of Proteobacteria and Firmicutes remained unchanged in organic chicken irrespective of the methods used, a noticeable shift in the Proteobacteria and Firmicutes ratio (59%:39% in rinsed to 38%:60% in enriched) was observed in conventional chicken. Furthermore, the choice of method did not yield any differences in Abundance-Based Coverage Estimator, and Jackknife, among conventional and organic chickens but resulted in a statistically significant difference in the Shannon, Simpson, Chao1, and phylogenetic diversity indices (p < 0.05). The relative abundance of Salmonella and Campylobacter was less than 0.1%. The results suggested the WCE method provides a broad range of information on the chicken microbiome.

Assessment of in-plant decontamination of broiler carcasses by immersion in hot water and lactic acid in Norway

This study investigated the effect of hot-water immersion, at different water temperatures and exposure times, on the microbiological loads on broiler carcasses. The combinations tested were 70 °C for 3 s, 80 °C for 3 s and 6 s, and 90 °C for 3 s. The separate effects of immersion in 5% lactic acid at 15 °C for 3 s and the on-line cold-water spray carousel on microbiological loads were also investigated. The study was conducted at a commercial broiler abattoir in Norway, where 110 carcasses were collected directly from the slaughter line after evisceration but before the cold-water carousel and brought to a separate room for immersion testing and microbiological sampling. Each carcass was assessed for skin injuries and discoloration post treatment, and sampling was by whole carcass rinse. Skin damage following hot-water treatment was not observed. A white coating developed on the skins of carcasses treated with 5% lactic acid after drying. For untreated carcasses, total plate count (TPC) mean was 4.9 log cfu/ml and E. coli mean was 4.0 log cfu/ml. Mean TPC were significantly lower (by 1.0–1.1 log cfu/ml) for carcasses immersed in hot water at 80 °C (3 and 6 s) and 90 °C. Only immersion in 80 °C for 6 s significantly reduced the E. coli mean (by 1.1 log cfu/ml). Immersion in 5% lactic acid reduced TPC by 4.0 log cfu/ml and E. coli by 3.9 log cfu/ml, with 9 of 10 samples below the detection level for E. coli. The cold-water carousel resulted in an insignificant reduction in TPC and E. coli levels. In conclusion, immersion for 6 s in 80 °C was the most effective hot-water treatment. Although lactic acid immersion is more effective, it is currently not permitted to use on broiler carcasses in Europe.

Bio-Mapping of Microbial Indicators and Pathogen Quantitative Loads in Commercial Broiler Processing Facilities in South America.

A bio-mapping study was conducted with the aim of creating a microbiological baseline on indicator organisms and pathogens in commercial broiler processing facilities located in a country in South America. Whole chicken carcass and wing rinses were collected from five stages of the poultry processing line: live receiving (LR), rehanger (R), post-evisceration (PE), post-chilling (PC), and wings (W). Rinses (n = 150) were enumerated using the MicroSnap™ system for total viable counts (TVC) and Enterobacteriaceae (EB), while the BAX®-System-SalQuant® and BAX®-System-CampyQuant™ were used for Salmonella and Campylobacter, respectively. TVC and EB were significantly different between stages at the processing line (p < 0.01). There was a significant reduction from LR to PC for both microbial indicators. TVC and EB counts increased significantly from PC to W. Salmonella counts at PC were significantly different from the other stages at the processing line (p = 0.03). Campylobacter counts were significantly higher than the other stages at PC (p < 0.01). The development of bio-mapping baselines with microbial indicators showed consistent reduction up to the post-chilling stage, followed by an increase at the wings sampling location. The quantification of pathogens demonstrates that prevalence analysis as a sole measurement of food safety is not sufficient to evaluate the performance of processing operations and sanitary dressing procedures in commercial processing facilities.

The Role of Dietary Supplementation of Yeast Cell Walls in Response to a Campylobacter jejuni Inoculation in Broiler Chickens.

Controlling Campylobacter jejuni during broiler production is a topic of interest from a public health standpoint, as colonized birds can contaminate poultry products during processing and sicken humans if not properly cooked or handled before consumption. The aim of this study was to evaluate dietary yeast cell wall (YCW) as a potential alternative to antibiotic growth promoters with or without a C. jejuni challenge. A total of 2240 day-old Ross 708 males were randomly assigned within 8 experimental groups with a 4 × 2 factorial design, with 4 diets (negative control [CTL-], positive control [CTL+, bacitracin, 50 g/ ton], YCW constant dose [400 g/ton], and YCW step-down dose [SD, 800, 400, and 200 g/ton in the starter, grower, and finisher periods, respectively]) and with or without a Day-16 C. jejuni oral gavage challenge at a 103-colony-forming-units (CFU)/ml dose. Body weights and feed consumption were measured on Days 0, 14, 28, and 41 to determine broiler performance. Ileum tissue samples were collected from 24 birds per treatment on Days 17 and 24 (1 and 8 days postinoculation [PI]) for relative gene expression (RGE) analysis. Cecal content samples were collected from 24 birds per treatment on Days 24, 34, and 42 for C. jejuni enumeration and prevalence calculation. A total of 80 birds per treatment were processed to determine carcass yield on Day 44, and on Day 45, 16 carcass rinsates per treatment were collected for C. jejuni enumeration and prevalence calculation. The interaction between diet and inoculation did not influence growth performance (P > 0.05). However, a diet effect was observed in the starter period where birds fed SD diet had a lower feed conversion ratio than birds fed CTL- diet (P = 0.0165). Additionally, the treatment of birds inoculated with C. jejuni fed with SD had a trend to a lower feed conversion ratio during the grower period (P = 0.0550). The RGE of interleukin 1β and interleukin 10 was similar in all treatments 1 and 8 days PI. The RGE of avian beta defensin 10 was similar in all treatments on Day 1 PI, but different on Day 8 PI (P = 0.0476). All birds inoculated with C. jejuni had similar CFU per milliliter counts in the cecal contents at Days 24, 34, and 42 (P > 0.05), and all birds inoculated with phosphate-buffered saline were negative for C. jejuni after prevalence testing. After processing 1) carcass yield was similar in all treatments (P > 0.05); 2) C. jejuni-inoculated birds fed CTL- had lower CFU per milliliter counts than birds provided CTL+ and constant-dose diets (P = 0.0383); and 3) all birds inoculated with PBS were negative for Campylobacter. Overall, under the conditions of this study, the addition of YCW during a C. jejuni challenge did not have an impact on growth performance, innate immune response, cecal colonization, carcass yield, or carcass colonization after processing.

Filter sterilized carcass rinsate for recovery of Salmonella species with various concentrations of cetylpyridinium chloride.

Controlling Salmonella in poultry processing continues to be important to processors and consumers. Cetylpyridinium chloride (CPC) has proven to be effective in vitro in controlling Salmonella. This study evaluated the recovery of Salmonella after overnight storage in 4°C filter-sterilized carcass rinsate containing CPC from 0.44 to 909 ppm (μg/mL). Ten Salmonella serotypes (18 strains), of which 6 serotypes are commonly isolated from poultry products, were grown in Bacto-Tryptic Soy Broth overnight at 37°C. Serial dilutions of a CPC/propylene glycol solution were prepared in 24-well tissue culture plates containing filter-sterilized carcass rinsate. Approximately 107 cfu/mL of each Salmonella serotype was added to the appropriate wells. Inoculated plates were stored overnight at 4°C. After storage, triplicate plates of brilliant green agar with sulfapyridine (BGS) were surface inoculated with 10 μL of the contents for each well, streaked for isolation, and incubated at 37°C for 24 h. Three replications were conducted. The presence of typical colonies on BGS plates was recorded as growth and verified through biochemical and serological testing. Of the serotypes chosen, Salmonella Kentucky, Dublin, and Enteritidis were the least resistant to CPC with a median minimum inhibitory concentration (MIC) of 14.22 μg/mL (range from 3.55 to 56.88 μg/mL); S. Typhimurium demonstrated a median MIC of 114.00 μg/mL (range from 28.44 to 114.00 μg/mL). Residual CPC potentially remaining attached to a carcass or in the weep after processing could potentially alter which Salmonella serotype is recovered from a carcass rinse due to different growth patterns during regulatory testing, with a potential for more virulent strains not to be recovered.

The Microbial Genetic Diversity and Succession Associated with Processing Waters at Different Broiler Processing Stages in an Abattoir in Australia

The high organic content of abattoir-associated process water provides an alternative for low-cost and non-invasive sample collection. This study investigated the association of microbial diversity from an abattoir processing environment with that of chicken meat. Water samples from scalders, defeathering, evisceration, carcass-washer, chillers, and post-chill carcass rinsate were collected from a large-scale abattoir in Australia. DNA was extracted using the Wizard® Genomic DNA Purification Kit, and the 16S rRNA v3-v4 gene region was sequenced using Illumina MiSeq. The results revealed that the Firmicutes decreased from scalding to evisceration (72.55%) and increased with chilling (23.47%), with the Proteobacteria and Bacteroidota changing inversely. A diverse bacterial community with 24 phyla and 392 genera was recovered from the post-chill chicken, with Anoxybacillus (71.84%), Megamonas (4.18%), Gallibacterium (2.14%), Unclassified Lachnospiraceae (1.87%), and Lactobacillus (1.80%) being the abundant genera. The alpha diversity increased from scalding to chilling, while the beta diversity revealed a significant separation of clusters at different processing points (p = 0.01). The alpha- and beta-diversity revealed significant contamination during the defeathering, with a redistribution of the bacteria during the chilling. This study concluded that the genetic diversity during the defeathering is strongly associated with the extent of the post-chill contamination, and may be used to indicate the microbial quality of the chicken meat.

Effects of dietary yeast cell wall supplementation on growth performance, intestinal Campylobacter jejuni colonization, innate immune response, villus height, crypt depth, and slaughter characteristics of broiler chickens inoculated with Campylobacter jejuni at d 21

A study was conducted to assess the effects of a dietary yeast cell wall (YCW) with and without a Campylobacter jejuni (CJ) challenge. A total of 2,240-day-old Ross 708 males were randomly assigned within 8 treatments with a 4×2 factorial design, with 4 diets (negative control, positive control, YCW constant dose (400 g/ton), and YCW step-down dose (800/400/200 g/ton in the starter/grower/finisher diets, respectively) and with and without d 21 CJ oral gavage challenge at 5.2×107 CFU/mL. At d 0, 14, 28, and 41 body weights and feed consumption were measured to determine performance. At d 14, 28, and 42, 8 jejunal and ileal histology samples per treatment were collected for villi morphology measurements. At d 22 and 28 (1- and 7-days postinoculation), 24 ileal tissue samples per treatment were collected for relative gene expression analysis. At d 42, 24 cecal content samples per treatment were collected for CJ enumeration. Finally, on d 44, 96 birds per treatment were processed to determine carcass yield and 16 carcass rinses per treatment were collected to determine CJ prevalence after processing. Diet or inoculation did not impact broiler performance (P > 0.05). Limited differences were observed in intestinal morphology, and villus height and crypt depth were different only in the ileum at d 42 (P=0.0280 and P=0.0162, respectively). At d 1 postinoculation, differences between treatments inoculated with CJ and PBS were observed in the expression of avian beta defensin 10 (AvBD10), interleukin 1ß (IL-1ß), and interleukin 10 (IL-10) (P < 0.05). At d 7 postinoculation, expression of AvBD10, IL-1ß, and IL-10 was similar among all treatments (P > 0.05). At d 42, all birds, regardless the inoculation, had similar levels of CJ recovered from cecal contents (P > 0.05). After processing, carcass yield and CJ prevalence postchilling was similar in all treatments (P > 0.05). Overall, under the conditions of this study, the addition of YCW during a CJ challenge did not have an impact in growth performance, innate immune response, cecal colonization, carcass yield, or CJ prevalence after processing.

Complete Genome Sequences of Two Salmonella enterica Strains Isolated from Chicken Carcass Rinse Water in Thailand.

We report the circularized complete genome sequences, containing a circular chromosome and two circular plasmids, of strains SalSpp05 (4.9 Mbp) and SalSpp10 (4.8 Mbp), which were isolated from chicken carcass rinse water samples; the sequences were obtained by combining Oxford Nanopore Technologies long-read data and Illumina short-read data. Whole-genome alignments indicated that both strains belong to Salmonella enterica.

Biomapping salmonella serovar complexity in broiler carcasses and parts during processing

Salmonella contamination of poultry remains a food safety challenge for broiler processors. The objectives of this study were to measure the efficacy of antimicrobial interventions in commercial broiler processing plants to reduce Salmonella and to assess changes in the Salmonella serovars before and after the chilling process. Three commercial processing plants were visited during 2020–2021 and 660 carcass rinse samples collected at three locations (before and after the pre-chiller, and after the main chiller) plus 80 drumstick samples across eight independent visits were collected and screened for Salmonella. Overall, Salmonella was detected in carcass rinse samples collected at 66% (145/220) pre pre-chill, 13.2% (29/220) post pre-chill and 2.3% (5/220) post-chill locations. Serovars Typhimurium, Infantis, and Kentucky were most commonly identified. CRISPR-SeroSeq was used to assess serovar populations and approximately 40% of carcasses (41.2% pre pre-chill and 37.0% post pre-chill) contained more than one serovar (range 1–4 serovars per carcass). Two out of five post-chill carcasses also contained multiple serovars. The low Salmonella incidence post intervention limited any conclusions about survival of particular serovars. Our data shows that serovar presence varies between flocks, even within the same broiler complex and CRISPR-typing also reveals evidence of multiple strains of the same serovar within a flock processed on the same day. We also compared Salmonella serovar populations across 128 paired samples (256 total samples), encompassing samples enriched in both RV and TT broths and found high concordance (Bray-Curtis <0.3) in 93% of samples. This study shows that antimicrobial interventions significantly reduce Salmonella on the carcasses during chilling and demonstrates effective use of a novel deep serotyping technology to track Salmonella serovars through processing.

Comparison between LASSO and RT methods for prediction of generic E. coli concentration in pastured poultry farms

Though most strains of E. coli are non-pathogenic components of the intestinal microbiome, certain pathogenic E. coli strains are the cause of diseases and outbreaks. Poultry is identified as a common reservoir for pathogenic E. coli. It is important to identify farm practice factors associated with E. coli in the pastured poultry environment. The objective of this study is to develop models that can predict E. coli levels and to select farm practice factors contributing to E. coli concentration in pastured poultry farms. Five kinds of samples: feces, soil, whole carcass rinse after processing (WCR-P), final product after chilling and storage (WCR-F), and ceca samples were collected for E. coli counts from 11 pastured poultry farms in the southeastern US. The regression tree (RT) and least absolute shrinkage and selection operator (LASSO) methods were applied to data from each sample type. The farm management practices and processing factors such as source of eggs, type of feed used, appearance of other animals on farm, chilling method, and storage time and temperature were all considered as possible explanatory factors in the models. Models were developed to predict the levels of E. coli and to select the most important factors used in predicting E. coli population. Model performances were compared using root mean square error (RMSE). For feces samples, average number of birds and animal source were the two most important variables affecting E. coli population by LASSO. The RT selected animal source, brood feed, day of year, flock age in days, and flock size as the most important variables in predicting E. coli concentration. The RMSE (in log10 scale) under LASSO was 0.974, while under RT it was 1.032 for feces samples. The predictive models provide practical and effective tools to predict E. coli population and to identify farm practice factors that affect E. coli levels.

Using E. coli population to predict foodborne pathogens in pastured poultry farms

Escherichia coli shows the potential of indicating foodborne pathogens. The purpose of this study is to investigate the association between E. coli and foodborne pathogens such as Campylobacter, Salmonella, and Listeria in pastured poultry farms, as well as in related processing facilities. Five different sample types: (i) feces, (ii) soil, (iii) whole carcass rinse during processing (WCR-P), (iv) whole carcass rinse of final product after chilling and storage (WCR-F), and (v) ceca were measured for E. coli populations. A logistic regression model for pathogen presence was developed for each sample type. The E. coli population significantly increased the predicted probability of Salmonella presence for soil and WCR-P samples (p = 0.0011 and p = 0.0157 respectively). For Campylobacter, the initial prevalence in feces and ceca were high and a decreasing trend of detecting Campylobacter was observed as E. coli concentration increased. In soil and WCR-P models, the probability of the presence of Campylobacter significantly increased as E. coli population increased. These models provide a practical and effective way of evaluating the relationship between E. coli and foodborne pathogens and enable prediction of foodborne pathogen presence based on E. coli prevalence within the pastured poultry farm-to-fork continuum.

Distribution and Transfer of Plasmid Replicon Families among Multidrug-Resistant Enterococcus faecalis and Enterococcus faecium from Poultry.

The presence and transfer of plasmids from commensal bacteria to more pathogenic bacteria may contribute to the dissemination of antimicrobial resistance. However, the prevalence of plasmids from commensal bacteria, such as the enterococci, in food animals remains largely unknown. In this study, the diversity and prevalence of plasmid families from multidrug-resistant (MDR; resistance to three or more antimicrobials) enterococci from poultry carcasses were determined. Plasmid-positive MDR enterococci were also tested for the ability to transfer plasmids to other enterococci using conjugation. MDR Enterococcus faecalis (n = 98) and Enterococcus faecium (n = 696) that were isolated from poultry carcass rinsates between 2004 and 2011 were tested for the presence of 21 plasmid replicon (rep) families using multiplex PCR. Approximately 48% of E. faecalis (47/98) and 16% of E. faecium (110/696) were positive for at least one rep-family. Fourteen rep-families were detected overall, and ten rep-families were shared between E. faecalis and E. faecium. The rep7 and rep17 families were unique to E. faecalis, while the rep5 and rep8 families were unique to E. faecium. The rep9 family was predominant in both E. faecalis and E. faecium for all the years tested. The greatest number of rep-families detected was in 2005 (n = 10), and the least was in 2009 (n = 1). Eight rep-families were transferred from E. faecalis donors to the E. faecalis JH2-2 recipient using conjugation. Results from this study showed that E. faecalis and E. faecium from poultry carcasses contain numerous and diverse rep-families that are capable of conjugal transfer.

Validation of RapidChek®Campylobacter Test System for the Detection of C. jejuni, C. coli, and C. lari in Poultry Samples: AOAC Performance Tested MethodSM 052201.

Campylobacter is one of the leading causes of human bacterial gastroenteritis worldwide. Campylobacter infections are most often associated with the consumption of raw milk, undercooked poultry, and contaminated water. The RapidChek®Campylobacter test system (PTM number 052201) was validated for the detection of Campylobacter jejuni, C. coli, and C. lari in raw ground chicken, chicken carcass rinse, and turkey carcass sponges. The method uses a proprietary enrichment medium. Following aerobic enrichment, an immunochromatographic test strip is inserted into the tube containing the enrichment, developed for 20 min, and interpreted. Campylobacter-inoculated food samples were tested by the method, as well as the USDA/FSIS cultural reference method; Isolation and Identification of Campylobacter jejuni/coli/lari from Poultry Rinse, Sponge and Raw Product Samples MLG 41.04. The candidate method was also confirmed by an alternative cultural method. The RapidChek method was tested with 50 Campylobacter strains comprised of C. jejuni, C. coli, and C. lari, and 30 non-target strains. A total of 80 low-level spiked samples were tested by both methods in the study. The candidate method yielded 49 presumptive positives: all presumptive results were confirmed culturally. The reference method produced a total of 41 confirmed positive results. No difference between the alternate confirmation method and reference confirmation method was observed. Probability of detection analysis demonstrated no significant differences in the number of positive samples detected by the candidate method and cultural reference method. The RapidChek method detected all 50 Campylobacter strains and none of the 30 non-target strains, including Campylobacter spp. other than C. jejuni, C. coli, and C. lari. The candidate method performed as well as the reference method in the detection of C. jejuni, C. coli, and C. lari in raw ground chicken, chicken carcass rinse, and turkey carcass sponges. Aerobic enrichment of selected matrixes for 48 h yielded reliable presumptive results for Campylobacter.

Consequences of Implementing Neutralizing Buffered Peptone Water in Commercial Poultry Processing on the Microbiota of Whole Bird Carcass Rinses and the Subsequent Microbiological Analyses.

In 2016, the United States Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS) established guidelines which modified the Buffered Peptone Water (BPW) rinsate material to include additional compounds that would better neutralize residual processing aids and allow for better recovery of sublethal injured Salmonella spp. cells. While the added compounds improved the recovery of Salmonella spp., specific data to understand how the new rinse agent, neutralizing Buffered Peptone Water (nBPW), impacts the recovery of other microorganisms such as Campylobacter spp. and indicator microorganisms are lacking. Therefore, this study evaluated the impact of rinse solutions (BPW or nBPW) used in Whole Bird Carcass rinsate (WBCR) collections on the subsequent microbiome and downstream culturing methodologies. Carcasses exiting a finishing chiller were rinsed in 400 ml of BPW or nBPW. Resulting rinsates were analyzed for Enterobacteriaceae (EB), Salmonella, and Campylobacter spp. prevalence and total aerobic bacteria (APC) and EB load. The 16S rDNA of the rinsates and the matrices collected from applied microbiological analyses were sequenced on an Illumina MiSeq®. Log10-transformed counts were analyzed in JMP 15 using ANOVA with means separated using Tukey’s HSD, and prevalence data were analyzed using Pearson’s χ2 (P ≤ 0.05). Diversity and microbiota compositions (ANCOM) were analyzed in QIIME 2.2019.7 (P ≤ 0.05; Q ≤ 0.05). There was an effect of rinsate type on the APC load and Campylobacter spp. prevalence (P < 0.05), but not the quantity or prevalence of EB or Salmonella spp. prevalence. There were differences between the microbial diversity of the two rinsate types and downstream analyses (P < 0.05). Additionally, several taxa, including Streptococcus, Lactobacillus, Aeromonas, Acinetobacter, Clostridium, Enterococcaceae, Burkholderiaceae, and Staphylococcaceae, were differentially abundant in paired populations. Therefore, the rinse buffer used in a WBCR collection causes proportional shifts in the microbiota, which can lead to differences in results obtained from cultured microbial populations.

Molecular Epidemiology of Salmonella enterica in Poultry in South Africa Using the Farm-to-Fork Approach.

The presence of the zoonotic pathogen Salmonella in the food supply chain poses a serious public health threat. This study describes the prevalence, susceptibility profiles, virulence patterns, and clonality of Salmonella from a poultry flock monitored over six weeks, using the farm-to-fork approach. Salmonella was isolated using selective media and confirmed to the genus and species level by real-time polymerase chain reaction (RT-PCR) of the invA and iroB genes, respectively. Antimicrobial susceptibility profiles were determined using Vitek-2 and the Kirby–Bauer disk diffusion method against a panel of 21 antibiotics recommended by the World Health Organisation Advisory Group on Integrated Surveillance of Antimicrobial Resistance (WHO-AGISAR). Selected virulence genes were identified by conventional PCR, and clonality was determined using enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). Salmonella was present in 32.1% of the samples: on the farm (30.9%), at the abattoir (0.6%), and during house decontamination (0.6%). A total of 210 isolates contained the invA and iroB genes. Litter, faeces, and carcass rinsate isolates were classified as resistant to cefuroxime (45.2%), cefoxitin (1.9%), chloramphenicol (1.9%), nitrofurantoin (0.4%), pefloxacin (11.4%), and azithromycin (11%). Multidrug resistance (MDR) was observed among 3.8% of the isolates. All wastewater and 72.4% of carcass rinsate isolates were fully susceptible. All isolates harboured the misL, orfL, pipD, stn, spiC, hilA, and sopB virulence genes, while pefA, spvA, spvB, and spvC were absent. In addition, fliC was only present among the wastewater isolates. Various ERIC-PCR patterns were observed throughout the continuum with different subtypes, indicating the unrelated spread of Salmonella. This study concluded that poultry and the poultry environment serve as reservoirs for resistant and pathogenic Salmonella. However, there was no evidence of transmission along the farm-to-fork continuum.

Prevalence of Salmonella enterica in poultry processing lines of central Kerala

Salmonella enterica is the most pathogenic species frequently responsible for foodborne Salmonella infections in humans. Occurrence of Salmonella enterica in poultry processing lines is a potential risk for the contamination of poultry meat and processing environment. Crosscontamination of carcasses by Salmonella spp. during processing could pose food safety risks. Therefore, the present study involved the detection of Salmonella enterica in the poultry processing lines. The cloacal swabs, caecal contents and carcass rinsates of the birds were collected from processing lines of two processing plants one each from Thrissur and Ernakulam districts of Kerala. The Salmonella spp. were isolated by conventional culture technique on Xylose–lysine deoxycholate agar. The molecular confirmation of Salmonella spp. and S. enterica was carried out by targeting invA and iroB gene, respectively. Out of 450 samples analysed from both the processing lines, 14.22 per cent of the isolates were found to be positive for Salmonella spp. by PCR. The invA gene was detected in 67.19 per cent of the isolates and iroB genes was detected in 81.4 per cent of the Salmonella spp. isolates. Implementation of standard sanitation protocol and hygiene strategies is required to reduce cross-contamination of poultry carcasses.

Salmonella Diversity Along the Farm-to-Fork Continuum of Pastured Poultry Flocks in the Southeastern United States

Greater consumer demand for all natural, antibiotic-free poultry products has led to an increase in pastured poultry operations. Given the increased level of environmental interaction, and the potential increase in exposure to foodborne pathogens, a greater understanding of the prevalence and diversity of Salmonella populations inherent within pastured poultry flocks. To achieve this, 42 pastured poultry flocks from 11 farms were sampled using a farm-to-fork strategy and Salmonella was isolated and characterized through pre-harvest (feces, soil) to post-harvest (ceca, whole carcass rinse) to the final product (whole carcass rinse) the consumer would purchase. Salmonella was isolated from 353 of a total of 2,305 samples, representing an overall prevalence of 18.1%. By far the most prevalent serotype was Kentucky (72.7% of all isolates), with &amp;lt;16% of all Salmonella representing a top serotype of concern for human health according to the CDC. Even though these flocks were raised antibiotic-free, Salmonella isolates exhibited resistances to a variety of antibiotics, with the two most common resistances being toward tetracycline and streptomycin (68.8 and 64.4% of all isolates, respectively); however, almost 98% of the multidrug resistant isolates were serotype Kentucky. Salmonella prevalence and diversity (both in terms of serotypes and antibiotic resistance profiles) were related more to the farm location than to the type of sample from which the Salmonella was isolated from along the farm-to-fork continuum. Based on these data, while Salmonella prevalence was similar to that from conventional poultry operations, serotypes of lesser concern to human health (Kentucky, Indiana) tended to fill the ecological niche for Salmonella species throughout the farm-to-fork continuum in these pastured poultry flocks. The diversity of these Salmonella populations tended to be farm specific, indicating the need for more tailored intervention strategies to continue to enhance the safety of these products.