ABSTRACT
The control of bacterial contaminants on chicken meat is a key area of interest in the broiler industry. Microbes that pose a significant food safety risk on chicken include Campylobacter spp., Salmonella enterica, Listeria monocytogenes and Escherichia coli. In addition, microbes including Pseudomonas spp., Brochothrix thermosphacta and Lactic Acid Bacteria must be controlled to ensure product quality and maintain shelf-life. Poultry meat processing challenges including cold and chemical exposure are employed to control the microbiota of the end-product, as well as to maintain environment hygiene. Exposure to these stresses can also induce adaptive shifts in the transcriptome and proteome of foodborne bacteria. This review will explore the complex interactions at play in the poultry processing environment and explain how bacteria exposed to such stresses behave in this environmental niche through the production of heat and cold-shock proteins, the expression of efflux pumps, sporulation, and the formation of mono- and mixed-species biofilms within the production environment.
Subject(s)
Food Microbiology , Listeria monocytogenes , Animals , Chickens , Food Safety , Meat/microbiology , PoultryABSTRACT
Chickens play host to a diverse community of microorganisms which constitute the microflora of the live bird. Factors such as diet, genetics and immune system activity affect this complex population within the bird, while external influences including weather and exposure to other animals alter the development of the microbiome. Bacteria from these settings including Campylobacter and Salmonella play an important role in the quality and safety of end-products from these birds. Further steps, including washing and chilling, within the production cycle aim to control the proliferation of these microbes as well as those which cause product spoilage. These steps impose specific selective pressures upon the microflora of the meat product. Within the next decade, it is forecast that poultry meat, particularly chicken will become the most consumed meat globally. However, as poultry meat is a frequently cited reservoir of zoonotic disease, understanding the development of its microflora is key to controlling the proliferation of important spoilage and pathogenic bacterial groups present on the bird. Whilst several excellent reviews exist detailing the microbiome of poultry during primary production, others focus on fate of important poultry pathogens such as Campylobacter and Salmonella spp. At farm and retail level, and yet others describe the evolution of spoilage microbes during spoilage. This review seeks to provide the poultry industry and research scientists unfamiliar with food technology process with a holistic overview of the key changes to the microflora of broiler chickens at each stage of the production and retail cycle.
Subject(s)
Bacteria/isolation & purification , Chickens/microbiology , Microbiota , Animals , Bacteria/classification , Bacteria/genetics , Bacteria/growth & development , Chickens/growth & development , Farms , Food Handling , Food Microbiology , Meat/microbiologyABSTRACT
1. This review explores current and proposed on-farm interventions and assess the potential of these interventions against Campylobacter spp. 2. Interventions such as vaccination, feed/water-additives and, most importantly, consistent biosecurity, exhibit potential for the effective control of this pathogen and its dissemination within the food chain. 3. Due to the extensive diversity in the Campylobacter spp. genome and surface-expressed proteins, vaccination of poultry is not yet regarded as a completely effective strategy. 4. The acidification of drinking water through the addition of organic acids has been reported to decrease the risk of Campylobacter spp. colonisation in broiler flocks. Whilst this treatment alone will not completely protect birds, use of water acidification in combination with in-feed measures to further reduce the level of Campylobacter spp. colonisation in poultry may be an option meriting further exploration. 5. The use of varied types of feed supplements to reduce the intestinal population and shedding rate of Campylobacter spp. in poultry is an area of growing interest in the poultry industry. Such supplements include pro - and pre-biotics, organic acids, bacteriocins and bacteriophage, which may be added to feed and water. 6. From the literature, it is clear that a distinct, albeit not unexpected, difference between the performance of in-feed interventions exists when examined in vitro compared to those determined in in vivo studies. It is much more likely that pooling some of the discussed approaches in the in-feed tool kit will provide an answer. 7. Whilst on-farm biosecurity is essential to maintain a healthy flock and reduce disease transmission, even the most stringent biosecurity measures may not have sufficient, consistent and predictable effects in controlling Campylobacter spp. Furthermore, the combination of varied dietary approaches and improved biosecurity measures may synergistically improve control.
Subject(s)
Campylobacter Infections , Campylobacter , Poultry Diseases , Animals , Campylobacter Infections/prevention & control , Campylobacter Infections/veterinary , Chickens , Farms , Poultry Diseases/prevention & controlABSTRACT
The distribution of oestrogen and progesterone receptors in the equine genital tract was investigated by means of a modified dextran-coated charcoal method on samples collected from the vagina, the cervix and the uterus of 30 healthy adult Polish mares, divided into two groups on the basis of their serum progesterone levels. The concentrations of oestrogen and progesterone receptors were significantly (P < 0.05) lower in the vagina and the cervix than in the uterus, in agreement with data from human beings, cattle and pigs, which showed that the highest concentrations of oestrogen and progesterone receptors were localised respectively in the body and in the horns of the uterus.