Source: MISSISSIPPI STATE UNIV submitted to NRP
DETERMINING PRE-HARVEST STRATEGIES TO CONTROL SALMONELLA IN POULTRY TO SECURE THE SAFETY OF THE FOOD SUPPLY SYSTEM AND TO PROVIDE BEST MANAGEMENT PRACTICES TO POULTRY PRODUCERS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1030220
Grant No.
2023-68008-40766
Cumulative Award Amt.
$300,000.00
Proposal No.
2022-10076
Multistate No.
(N/A)
Project Start Date
Aug 1, 2023
Project End Date
Jul 31, 2026
Grant Year
2023
Program Code
[A1701]- Critical Agricultural Research and Extension: CARE
Recipient Organization
MISSISSIPPI STATE UNIV
(N/A)
MISSISSIPPI STATE,MS 39762
Performing Department
(N/A)
Non Technical Summary
The high prevalence of Salmonella spp. in poultry meat imposes a major burden on the industry. Even though data provided by the USDA (2022) shows that more than 92% of processing establishments meet or exceed USDA-FSIS performance standards, the national public health target for the number of Salmonella illnesses linked to poultry has not been met (USDA, 2022; USDA-FSIS, 2020). Although research has evaluated various pre-harvest and processing intervention strategies, the strategies have demonstrated limited effectiveness in reducing Salmonella illnesses associated with poultry products in people. It is important to understand the effect of combining multiple approaches to limit Salmonella colonization in chickens during production, as this will help to fill current knowledge gaps about Salmonella control that exists in the poultry industry. These objectives will help improve poultry safety by developing and implementing effective mitigation strategies at the production level, which will keep the flock prevalence and numbers of Salmonella spp. in colonized chickens at such low levels that contamination of meat becomes highly unlikely. As a result, the transmission of Salmonella spp. to humans is also reduced or eliminated. The Extension component will serve as a catalyst for transforming current management practices for farmers so that Salmonella spp. can be realistically eliminated from poultry litter, live birds, and poultry meat.
Animal Health Component
75%
Research Effort Categories
Basic
(N/A)
Applied
75%
Developmental
25%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
7123220110050%
9033220110050%
Knowledge Area
712 - Protect Food from Contamination by Pathogenic Microorganisms, Parasites, and Naturally Occurring Toxins; 903 - Communication, Education, and Information Delivery;

Subject Of Investigation
3220 - Meat-type chicken, live animal;

Field Of Science
1100 - Bacteriology;
Goals / Objectives
There are three objectives for this project with each objective building on the previous one. The first is to investigate the effects of a Salmonella marked strain's survivability using chemical and composting management practices in poultry litter. Additionally, the effects of organic acids in Salmonella colonization during production will be investigated. This is a farm-to-fork approach in which we will also be evaluating the prevalence of this Salmonella marker strain during poultry processing.The second objective is to use a MiniSeq genome sequencer and standard culture techniques on samples collected from commercial poultry farms to determine Salmonella strains present in environmental samples and in the intestinal tract of market-age birds. Birds will then be followed to the processing plant and Salmonella spp. levels will be determined during processing. To ensure standardized evaluations, a standard sample collection method will be developed to be followed in every farm visit. All samples will be transported on the same day of collection and will be tested no later than 24 hours after collection.Samples from eight commercial poultry farms in the states of Alabama and Mississippi will be obtained. To cover a range of management practices, sampling will take place in four separate production complexes and two farms per complex.The third objective is to create educational products to help poultry producers develop and implement BMPs focused on Salmonella control. To reach a diverse set of producers throughout the region, we will take a tiered approach to outreach using written materials, webinars, and technology-based outreach systems such as Extension TV.
Project Methods
Objective one centers around Salmonella contamination on the farm and how it may persist in the house and infect subsequent flocks. This will be performed by challenging the first flock with a marker strain of Salmonella and then recovering this Salmonella in two subsequent flocks. The treatments to be evaluated are treating the litter with a common litter treatment, windrow composting the litter or performing nothing to the litter. Each of the three flocks will be processed and samples collected for Salmonella enumeration and prevalence. Samples will be collected for Salmonella enumeration and prevalence after each flock. The second objective is additional sampling on the farm and following these birds through processing, however, this will be performed on commercial poultry operations, specifically from 8 poultry farms from 4 poultry complexes. From here we will be able to identify and develop BMPs that we will use for objective 3.For each sample type collected, Salmonella will be detected through both classical culture and molecular detection techniques. Classical culture techniques will include standard methods as described by the USDA MLG 4.10. The molecular detection will be done using a Molecular Detection System (MDS) (3M, 2022). The MDS combines isothermal deoxyribonucleic acid (DNA) amplification and bioluminescence detection technologies to detect pathogens of interest. The MDS uses multiple primers to recognize distinct regions of the genome and Bst DNA polymerase to provide continuous and rapid amplification of genetic material, therefore, the specificity is high (3M, 2011). Molecular/culture methods will be validated with proper controls to ensure that false positive/false negative results are minimized. Samples that are culture-positive for Salmonella also should be MDS positive for the organism. Once Salmonella has been detected, multiple isolates per sample will be serotyped at the National Veterinary Services Laboratory (NVSL) in Iowa to determine whether there is a single or mixture of serotypes present in the sample. Whole genome sequencing (WGS) will be used to compare strains of each serotype to determine if the detected isolates are the same as those detected previously, therefore indicating that Salmonella is being passed along the production chain from positive poultry litter. After Salmonella strains are serotyped, WGS will be used to compare strains of each serotype to determine if detected isolates have been passed along the production chain from the initial inoculation.

Progress 08/01/23 to 07/31/24

Outputs
Target Audience:For the first and second objectives the goal was to generate data that can be used to share with poultry farmers as well as to industry personal. To date the information from objecctive one has been shared with scientists, students and staff at the two unviersities (Auburn and MS State). In addtion the data generated has been informally shared with poultry producers, poultry company personal as well as to allied poultry companies personal. Changes/Problems:Objective one we had to substitute aluminum sulfate for formate salts. This in the end will better replicate what is currently used in the poultry industry. Objective two we will have to reduce the number of poultry production complexes from four to three due to lack of funds. However from the three complexes we will sample we should have a good representation of management practices performed by the poultry industry and be able to develop BMPs to disseminate from them. What opportunities for training and professional development has the project provided?In addition to the graduate student(s) and intern(s) funded by the grant, more than 10 graduate and undergraduate students have been trained in bird handling, isolation of Salmonella from various samples and litter treatments between flocks. How have the results been disseminated to communities of interest?To date the results for objecitve 2 have been shared at scientific meetings. For both objective one the data has been partially shared with the companies that donated product for the study. Objective two has been shared with participating companies and their farmers and has been used to improve their sanitation regime as well as inhance their rodent/insect control programs. What do you plan to do during the next reporting period to accomplish the goals?For objective one we are approximately three months behind schedule due to a longer than expected start-up period and the need to wait for a house to be available at the Auburn University research farm. In the next reporting period, we will finish the third flock, investigate samples that have been collected but have not yet been processed yet and analyze the results. We plan to submit at least three abstracts for international scientific meetings and prepare at least two manuscripts for publication in peer-reviewed journals. Objective 2 was initiated before the grant was finalzied due to a graduate student and their deadline to graduate. So this means we are ahead of schedule. This upcoming reporting period we will generate at least two abstract as well as two peer reviewed journal articles. For objective 3 in the upcoming reporting period we will produce at least one popular press paper for publicaiton. In additon we will perform at least one webinar. A lot depends on how quickly we can produce and interpret the findings from objectives one and two. Our eventual goal (year 3) is to host a series of workshops for poutlry producers and company perosonal in AL, MS, GA and other poultry producing states.

Impacts
What was accomplished under these goals? Objective 1 (Determine the effect of the combination of in-house litter composting and supplementation of water with organic acids to reduce/prevent Salmonella infection pressure in the environment and in the birds): The animal trial, which will cover three subsequent broiler flocks, has been started. The trial investigates in a 3 x 3 factorial design the effect of organic acids (control, acetic, and citric) in the drinking water and different litter treatments (control, composting, litter treatment) between flocks on Salmonella transmission between subsequent flocks after challenge of the first flock. The experimental plan was updated to use aluminum sulfate as litter treatment instead of sodium formate salts for litter treatment to better mimic current industry practices. The first two flocks have been successfully completed. Planned samples have been taken, which include cecal content and carcass rinses at the end of each flock, frequent boot swabs to track Salmonella throughout the growing periods, as well as individual fecal samples and litter samples to characterize the microbiota. The production data has been recorded. Objective 2 was initiated before the finalization of the grant, so substantially more has been completed. To date two commercial companies have been sampled. It is expected to take several more months to finish analyzing the data. However there are some trends that have been observed. The first is that insects and rodents seem to harbor Salmonella when birds are not present in the poultry house. The second is that the hatchery is a major area that Salmonella is spread from chicks that are contaminated to those that are not. This has been brought to the attention of the commercial hatchery's management and subsequent follow up studies in one case yielded no Salmonella, after having heavy contamination. The second hatchery the results have not yet been compiled. In both cases the hatchery management increased their sanitation practices, exactly what they did at this point we don't know. A third finding is that that in the complexes sampled there are several Salmonella in the population; however not all of them are present in each phase of poultry production. This is interesting and is in line with what others have observed. Over the next three to six months we will this data analyzed and a better idea of what is going on can be reported. Objective 3 is based on the findings of Objectives 1 and 2, at this point we have nothing to report for this objective; however by the end of this calendar year we will have generated some outputs in this area.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Y. Adhikari, M. A. Bailey, J. T. Krehling, K. S. Chasteen, L. Munoz, C. Escobar, L. Orellana, P. Gaonkar, S. Kitchens, D. V. Bourassa, S. B. Price, R. J. Buhr and K. S. Macklin. 2024. Core genome-based phylogeny of Salmonella isolated from various stages of No-Antibiotics-Ever (NAE) broiler complex. IPSF Annual Meeting, Jan 29-30, 2024. Atlanta, GA
  • Type: Conference Papers and Presentations Status: Submitted Year Published: 2024 Citation: Y. Adhikari, M. A. Bailey, P. Gaonkar, S. Kitchens, L. Munoz, D. V. Bourassa, S. B. Price, R. J. Buhr and K. S. Macklin. 2024. Detection of Salmonella from pullet through final raw product of a conventional broiler complex. PSA Annual Meeting, July 14-19, 2024. Louisville, KY.