Field Interventions Against Colonization of Broilers by Campylobacter

Abstract

Poultry accounts for a high proportion of human campylobacteriosis cases, and the problem of Campylobacter colonization of broiler flocks has proven to be intractable. Owing to their broad host range and genetic instability, Campylobacter organisms are ubiquitous and adaptable in the broiler farm environment, colonizing birds heavily and spreading rapidly after introduction into a flock. This review examines strategies to prevent or suppress such colonization, with a heavy emphasis on field investigations. Attempts to exclude Campylobacter via enhanced biosecurity and hygiene measures have met with mixed success. Reasons for this are becoming better understood as investigations focus on houses, ventilation, biosecurity practices, external operators, and compliance, among other factors. It is evident that piecemeal approaches are likely to fail. Complementary measures include feed and drinking water treatments applied in either preventive or suppressive modes using agents including organic acids and their derivatives, also litter treatments, probiotics, prebiotics, and alterations to diet. Some treatments aim to reduce the number of Campylobacter organisms entering abattoirs by suppressing intestinal colonization just before slaughter; these include acid water treatment or administration of bacteriophages or bacteriocins. Experimental vaccines historically have had little success, but some recent subunit vaccines show promise. Overall, there is wide variation in the control achieved, and consistency and harmonization of trials is needed to enable robust evaluation. There is also some potential to breed for resistance to Campylobacter. Good and consistent control of flock colonization by Campylobacter may require an as‐yet undetermined combination of excellent biosecurity plus complementary measures.

Salmonella control in poultry flocks and its public health impact

“…A higher occurrence of Salmonella in cage systems was observed in studies from multiple countries as cited by Holt et al (2011), more specifically including in Germany (Methner et al, 2006), the United Kingdom (Snow et al, 2010;Wales et al, 2010), France (Mahe et al, 2008), and Belgium (Namata et al, 2008).…”

“…Poultry flocks infected with Campylobacter also shed huge numbers of organisms; with flock prevalence increasing rapidly to approach 100% within days of the first bird becoming infected and with Campylobacter loads of between 6 and 9 logs CFU/g of caecal contents or fresh faeces. This makes it very difficult to avoid spreading infection between different flocks on a broiler farm once one flock has become infected or to prevent spread of infection by thinning personnel and equipment, which have very close contact with birds on a daily basis (Thornton, 2010;Higham et al, 2018;Wales et al, 2018).…”

Modulation of the Immune Response to Improve Health and Reduce Foodborne Pathogens in Poultry

“…A recent review eloquently covered the role of Campylobacter and Salmonella as causative agents of zoonotic foodborne disease, specifically addressing reservoirs for contamination, risk factors for contracting the disease, and the virulence mechanism(s) for each [9]. Campylobacter is “ubiquitous and adaptable” in broiler farms and once introduced can quickly colonize and spread through an entire flock [10]. As such, Campylobacter control will rely on a multifaceted approach ranging from enhanced biosecurity, feed/water treatments, litter amendments, and feed additives and yet may still only produce varied success.…”

Cost-effectiveness analysis of using probiotics, prebiotics, or synbiotics to control Campylobacter in broilers

“…Therefore, it is relevant to control Campylobacter on broiler farms. A number of interventions have been proposed to control Campylobacter risk factors on broiler farms ( Adkin et al., 2006 , McDowell et al., 2008 , Sommer et al., 2016 , Wales et al., 2019 ). The cost-effectiveness ratio of such interventions has been estimated in a number of studies.…”

“…Major variations exist between studies in, for example, the type of probiotic products and dosage used, ultimately, in the duration of Campylobacter colonization, and in Campylobacter load and prevalence ( Meunier et al., 2016 ). Licensed probiotics have been examined under commercial conditions, yet consistent large-scale results are scarce ( Wales et al., 2019 ). A coherent picture of the efficacy of probiotics to control Campylobacter prevalence and load under commercial conditions does not emerge ( Meunier et al., 2016 ).…”