The below list represents only planned manuscripts. Some of these
manuscripts have not been received by the Editorial Office yet. Papers
submitted to MDPI journals are subject to peer-review.
Type of Paper: Article
Title: Effect of Different Feed Structures and Bedding on the Horizontal Spread of Campylobacter jejuni within Broiler Flocks
Author: Birgitte Moen
Affiliation: The Norwegian Institute of Food, Fisheries and Aquaculture, Nofima, Osloveien 1, Norway
Abstract: The effect of feed structure and litter on spread of C. jejuni in broiler flocks was studied. Broiler chickens raised in 24 eight-bird group cages on either rubber mat or wood shavings were fed either a wheat-based control diet, a diet where 50% of the ground wheat was replaced by whole wheat prior to pelleting, or the control diet diluted with 12% oat hulls. Samples from the cloacal mucosa of all birds were taken daily for C. jejuni quantification and cecum samples were collected at the end of the experiment for C. jejuni quantification and microbiota analysis. Inclusion of whole wheat or oat hulls delayed the spread of C. jejuni in broiler flocks, but no significant differences were detected between types of structure included in the feed. No significant changes in the dominating microbiota in the lower GI tract were observed, which indicates that only the upper GI tract has an effect on feed structure. Delaying the spread of C. jejuni in broiler flocks, could at time of slaughter, result in fewer C. jejuni-positive broilers.
Type of Manuscript: Review
Title: Systemic Salmonella in Poultry: Identifying Research Needs to Improve Food Safety
Authors: Jennifer McEntire 1, Scott J. Eilert 2, Barbara J. Masters 3, Rafael E. Rivera 4
Affiliations: 1 Food and Import Safety, Leavitt Partners Global Food Safety Solutions; 2 Food Safety, Quality and Regulatory, Cargill Value Added Meats-Retail, 151 N. Main, Wichita, KS 67201, USA; 3 OFW Law Washington, District of Columbia; 4 Manager Food Safety & Production Programs, US Poultry & Egg Association
Abstract: Despite the application of on-farm controls and in-plant interventions, outbreaks of salmonellosis have been associated with ground poultry products. It has conventionally been assumed that contamination occurs at the tissue surface, and therefore can best be addressed through good sanitary dressing practices accompanied with surface treatments such as dips and sprays. However, if Salmonella can become systemic in poultry, this may warrant additional research determine if these Salmonella are introduced into the ground product. This paper reviews the existing research studying the ability of Salmonella to systemically infect poultry, and discusses future research needs and the implication for the ground poultry industry if Salmonella is not limited to surface contamination, as previously assumed.
Type of Paper: Article
Title: Buffering Capacity of Chicken Protects Salmonella against Hydrochloric Acid but not Organic Acid Treatment
Authors: Gary Dykes
Affiliations: School of Science, Monash University, Sunway Campus, Bandar Sunway, Selangor, Malaysia
Abstract: Acidic marinades have been suggested to improve chicken meat safety by eliminating pathogenic bacteria such as Salmonella. Chicken skin and meat are likely to have a buffering capacity which may help reduce the acidic pH of marinades. We investigated (1) the buffering capacity of chicken skin and meat and (2) the effects of organic acids and hydrochloric acid on the survival of Salmonella on chicken skin and meat. The buffering capacity of chicken meat and skin was investigated by measuring changes in the pH of phosphate buffered saline at pH 2, 3, 5, 7, 9 and 11 both before and after incubation at refrigeration temperature for 24 hours. In a separate experiment, two strains each of Salmonella Typhimurium and Salmonella Enteritidis were inoculated separately onto chicken skin and meat. The inoculated samples were treated with acetic acid, citric acid, lactic acid and hydrochloric acid (HCl) solutions ranging from 0.05M to 0.5M and incubated at refrigeration temperatures for 24 hours. The pH of the acid solutions was measured before and after incubation. Salmonella was enumerated before and after exposure to the acid solutions and compared to a control without the presence of chicken skin and meat. Chicken skin and meat showed buffering capacity and changed both acidic and alkaline solution pH towards neutrality. Chicken meat was shown to exert the best buffering effect by, for example, increasing pH 2 PBS to pH 4.8 (p<0.001). Numbers of Salmonella surviving on chicken decreased as the pH descreased. Among the four acids acetic acid resulted in the fastest (p<0.001) rate of reduction of Salmonella on chicken (slope of 8.8), followed by citric acid (slope of 5.69), lactic acid (slope of 5.26) and HCl (slope of 3.65). Acetic acid effectively eliminated Salmonella on chicken at ~pH 3.8 (p<0.001) while lactic acid and citric acid eliminated Salmonella at ~pH 2.5 and ~pH 2.9 (p>0.05), respectively. Elimination of Salmonella of HCl occurred at pH 1.2 (p<0.05). The buffering effect of chicken meat and skin protected Salmonella against extreme acidic conditions (pH 2) created by HCl, but did not protect Salmonella on chicken treated by organic acids at the same pH. This suggests that the antimicrobial mode of action of organic acid is due to other factors than its acidic pH. In addition, the ability of acetic acid to eliminate Salmonella on chicken meat at approximately pH 4 suggests it has potential for practical application in commercial marination.
Title: A Review on Microbiological Safety of Chicken Litter or Chicken Litter-Based Organic Fertilizer and Soil Amendment
Authors: Zhao Chen 1 and Xiuping Jiang 2
Affiliations: 1 Department of Biological Sciences, Clemson University, SC, USA; 2 Department of Food, Nutrition, and Packaging Sciences, Clemson University, SC, USA
Abstract: Chicken litter or chicken litter- based organic fertilizer and soil amendment is usually recycled into the soil to improve the structure and fertility of agricultural land. As an important source of nutrients for crop production, chicken litter may also contain a variety of human pathogens that can threaten humans who consume the contaminated food or water. Some foodborne pathogens have the great potential to survive for long periods of time in chicken litter or after land application, and a small population of pathogenic cells may regrow to high levels when the conditions are favorable for growth. Thermal processing is often a good choice for inactivating pathogens in chicken litter prior to land application. However, some populations may become acclimatized to desiccation environment during stockpiling and develop heat resistance through cross-protection during subsequent high temperature treatment. Therefore, this paper reviews available information on the microbiological safety of chicken litter or chicken litter-based organic fertilizer and soil amendment, and discusses about further research on developing novel and effective disinfection techniques as an attractive alternative to current methods.