Location: Poultry Microbiological Safety and Processing Research Unit
2018 Annual Report
Objectives
Objective 1. Develop reliable and reproducible challenge models with Salmonella and Campylobacter for use in accurately developing, evaluating, and validating processes for reducing pathogen load using various chemical sanitizers.
Objective 2. Develop, evaluate, and validate current and novel chemicals, operational protocols, and sampling methodologies used during poultry production and processing of broilers for the reduction and/or control of foodborne pathogens.
Sub-objective 2.1. Assess the ability of commercial and novel chemical sanitizers to reduce or eliminate Salmonella, Campylobacter, and Pseudomonas species from inoculated broiler carcasses and parts.
Sub-objective 2.2. Examine the effectiveness of chemical sanitizers applied to carcasses before defeathering or before chilling to reduce contamination by Salmonella and Campylobacter carcasses in postchill carcasses.
Sub-objective 2.3. Formulate novel microbicidal surfactants from mixtures of medium-chain fatty acids (MCFA) and organic acids (OA) to be used as sanitizers to significantly reduce microbial contamination during poultry processing.
Objective 3. Identify and evaluate risk factors in the production, management, transportation, or processing that impact bird/egg contamination with foodborne pathogens and develop intervention strategies to control pathogens in the absence of antibiotics.
Sub-objective 3.1. Assess the ability of chemical sanitizers to reduce contamination of inoculated, fertile eggs by Salmonella.
Sub-objective 3.2. Identify and evaluate risk factors in the production, management, transportation, or processing that impact broiler contamination with foodborne pathogens and develop intervention strategies to control pathogens in the absence of antibiotics.
Objective 4. Determine the extrinsic factors that impact the survival and attachment of microorganisms including evaluating media and growth factors. Develop and validate new improved technologies to isolate and propagate foodborne pathogens.
Sub-objective 4.1. Evaluate media and growth factors and use the findings to develop new, improved technologies for the isolation and propagation of Campylobacter.
Sub-objective 4.2. Assess accuracy of current laboratory methods in recovering Salmonella from poultry, animal feeds, and dry environmental samples with fermentable substrates available and development of a more efficient pre-enrichment media.
Approach
Poultry products contaminated by Salmonella and Campylobacter continue to be major sources of human foodborne illnesses. Live poultry are sporadically colonized by these pathogens, and the birds may serve as reservoirs for the bacteria without displaying any signs of illness or declines in performance. Cross contamination of carcasses during processing may spread the bacteria to poultry meat which may cause foodborne infections if the meat is not properly handled. Therefore, the primary goal of our research will be to develop novel interventions that may be used by commercial poultry producers and processors to reduce contamination of poultry by Salmonella, Campylobacter, and indicator microorganisms. Novel chemical sanitizers that may be used during processing to reduce carcass contamination by foodborne pathogens will be formulated or identified. Factors that enhance survival of these pathogens will be identified and used to formulate a novel bacteriological medium that will be utilized in research projects to determine the efficacy of currently available and newly developed interventions. The project outcomes will result in additional control measures that will reduce the levels of Salmonella and Campylobacter in broiler flocks and reduce contamination of processed carcasses by these pathogens. These outcomes will enable the poultry industry to achieve Food Safety Inspection Service (FSIS) performance standard goals and to reduce the number of cases of human foodborne illness associated with contaminated poultry products. Research goals will be achieved by utilizing an interdisciplinary approach that incorporates knowledge and skills of the scientists and other scientists who possess skills and resources required to successfully compete this project.
Progress Report
Progress has been made in evaluation of a calcium alginate suspension for attaching bacteria to the carcass skin. Other colloidal solutions for the application of bacteria the carcass skin are being evaluated.
Progress has been made in the evaluation of one low acid processing aid, plus several other chemicals (bromine) and the enhanced effect of applying more than one chemical in a specific sequence on the reduction of Campylobacter inoculated onto the breast skin and thigh skin of carcasses and parts.
Progress has been made in the evaluation of fluidic nozzles and high pressure on the removal of the bacterial load from broiler carcasses with ambient temperature water.
The recovery of inoculated Salmonella from the shells of broiler hatching eggs was enhanced with the partial removal of the eggshell cuticle, complete removal of albumen and yolk, or by inoculation through the shell into the air cell. However, after holding inoculated eggs for 24 hours at room temperature, Salmonella could no longer be recovered.
The addition of cetylpyridinium chloride, sodium bisulfate, nor hydrogen peroxide acidified to pH 5 to the drinking water for broilers prior to and during feed and water withdrawal prior to processing had no impact on Salmonella recovery from the broiler’s crop or ceca during or after feed withdrawal.
Studies were conducted to formulate a novel selective, bacteriological medium for growth of Campylobacter in containers incubated aerobically.
Progress includes work aimed at determining the effect of acidic conditions on the injury and death of Salmonella. Salmonella strains stressed with drying and heat are different from unstressed cultures. Stress made S. Typhimurium (ST) and S. Enteritidis (SE) more susceptible to acidity and S. Senftenberg (SS) less susceptible. Interestingly, ST and SE are not usually found in feed but SS is.
Accomplishments
1. Novel selective medium formulated to isolate Campylobacter from mixed cultures. ARS researchers at Athens, Georgia, formulated a new selective, medium that could be used in the aerobic isolation of Campylobacter from samples that also contained other bacteria. Three antibiotic mixtures were tested as supplements that could be added to the medium to allow the growth of Campylobacter while inhibiting the growth of other bacteria. Results of these experiments indicated that while the other bacteria could grow in media that contained no antibiotics, the growth of most of these bacteria was inhibited in the media supplemented with antibiotics. It was also determined that when Campylobacter was grown in cultures containing other bacteria, Campylobacter could outgrow the other bacteria in the media supplemented with the Bolton antibiotics, but not in the non-supplemented medium. These experiments show that supplementing the new medium with Bolton’s antibiotic produces a selective medium that could be used with aerobic incubation to isolate Campylobacter from samples containing other bacteria.
2. The time of day that poultry house litter is sampled does not impact the predicted Salmonella or Campylobacter status of the flock. ARS researchers at Athens, Georgia, demonstrated that the time of day that litter stepped-on-drag-swabs are collected from feed restricted pullet breeder pens did not alter Salmonella or Campylobacter recovery from the litter. Litter sampled at various times of the day were all 100% positive for Salmonella in 9, 11, and 17 week old birds; and litter sampled for Campylobacter at 17 and 18 week old birds were also 100% positive when samples at various times. The feces and litter contain Salmonella and Campylobacter at levels sufficient to be recovered from the pen litter prior to the chickens being fed, and also at 3 or 6 hours after feeding on the same day. These results indicate that once Salmonella or Campylobacter colonized the intestinal tract, Salmonella and Campylobacter are shed from the intestinal tract at levels recoverable from the litter at various sampling times.
Review Publications
Buhr, R.J., Bourassa, D.V., Hinton Jr, A., Fairchild, B.D., Ritz, C.W. 2017. Impact of litter salmonella status during feed withdrawal on salmonella recovery from the broiler crop and ceca. Poultry Science. 96:(12)4361-4369. doi.org10.3382/ps/pex231.
Bourassa, D.V., Wilson, K.M., Ritz, C.W., Kiepper, B.K., Buhr, R.J. 2017. Evaluation of the addition of organic acids in the feed and/or water for broilers and the subsequent recovery of salmonella typhimurium from litter and ceca. Poultry Science. 97:(1)64-73. doi.org/10.3382/ps/pex289.
Hinton Jr, A., Cox Jr, N.A. 2018. Selective medium for aerobic incubation of Campylobacter. Journal of Food: Microbiology, Safety, and Hygiene. 3(1):1-6.
Adhikari, P., Cosby, D.E., Cox Jr, N.A., Lee, J.H., Kim, W.K. 2017. Effect of dietary bacteriophage supplementation in internal organs, fecal excretion and ileal immune response in laying hens challenged with salmonella enteritidis. Poultry Science. 96(9):3264-3271. doi: 10.3382/ps/pex109.
Richardson, K.E., Cox Jr, N.A., Cosby, D.E., Berrang, M.E. 2018. Impact of desiccation and heat exposure stress on Salmonella tolerance to acidic conditions. Journal of Environmental Science and Health. Part B, 53:2:141-144. 10.1080/03601234.2017.1397467.
Berrang, M.E., Gamble, G.R., Hinton Jr, A., Johnson, J. 2018. Neutralization of residual antimicrobial processing chemicals in broiler carcass rinse for improved detection of Campylobacter. Journal of Applied Poultry Research. doi:10.3382/japr/pfx071.
Yeh, H., Line, J.E., Hinton Jr, A. 2018. Molecular analysis, biochemical characterization, antimicrobial activity and immunological analysis of Proteus mirabilis isolated from broilers. Journal of Food Science. 83(3):770-779. https://doi.org/10.1111/1750-3841.14056.
Wilson, K.M., Bourassa, D.V., Mclendon, B.L., Wilson, J., Buhr, R.J. 2018. Impact of skip-a-day and every-day feeding programs on the recovery of salmonella and campylobacter following in broiler breeder pullets. Poultry Science. 97(7):2775-2784. doi.org/10.3382/ps/pey150.
Bourassa, D.V., Wilson, K.M., Czarick, M., Buhr, R.J. 2018. Microbiological status of broiler respiratory tracts before and during catching for transport to the processing plant. Journal of Applied Poultry Research. doi.org/10.3382/japr/pfy029.
Mclendon, B.L., Cox Jr, N.A., Cosby, D.E., Montiel, E.R., Russell, S.M., Hofacre, C.L., Landrum, M.A., Jackson, J.S., Wilson, J.L. 2018. Detecting Campylobacter coli in young chicks using two different cloacal swab techniques. Journal of Applied Poultry Research. 27(2):223-227. https://doi.org/10.3382/japr/pfx061.
Liu, J.D., Bayir, H.O., Cosby, D.E., Cox Jr, N.A., Williams, S.M., Fowler, J. 2017. Evaluation of encapsulated sodium butyrate on growth performance, energy digestibility, gut development and Salmonella effect in broilers. Poultry Science. 96(10):3638-3644. doi.org/10.3382/ps/pex174.
Cox Jr, N.A., Cosby, D.E., Berrang, M.E., Richardson, K.E., Holcombe, N., Weller, C. 2017. The effect of environmental poultry samples on the pH of typical salmonella pre-enrichment and enrichment media following incubation. Journal of Applied Poultry Research. 27(1):112-115. doi.org/10.3382/japr/pfx056.
Cosby, D.E., Cox Jr, N.A., Harrison, M.A., Berrang, M.E., Wilson, J.L. 2018. Colonization of day-old broilers with gentamicin resistant Campylobacter coli following challenge via different inoculation routes. Journal of Veterinary Medicine and Research. 4(7):1096.
Adhikari, P., Cosby, D.E., Cox Jr, N.A., Kim, W.K. 2017. Effect of dietary supplementation of nitrocompounds on salmonella colonization and ileal immune gene expression in laying hens challenged with salmonella enteritidis. Poultry Science. 96(12):4280-4286.
