Bacteriophages to Control Campylobacter in Commercially Farmed Broiler Chickens, in Australia

Abstract

This study describes the development and use of bacteriophage cocktails to control Campylobacter in broiler chickens, in a commercial setting, in Queensland Australia, following the birds from farm to the processing plant. The components of the bacteriophage cocktails were selected to be effective against the maximum number of Campylobacter jejuni and Campylobacter coli isolates encountered on SE Queensland farms. Farms were identified that had suitable Campylobacter target populations and phage were undetectable 1 week prior to the intended treatment. Cocktails of phages were administered at 47 days of age. Groups of study birds were slaughtered the following day, on-farm, at the end of flock transport to the plant, and at processing (approximately 28 h post-treatment). On Farm A, the phage treatment significantly reduced Campylobacter levels in the ceca at the farm in the range of 1-3 log 10 CFU/g (p = 0.007), compared to mock treated controls. However, individual birds sampled on farm (1/10) or following transport (2/10) exhibited high cecal Campylobacter counts with low phage titers, suggesting that treatment periods > 24 h may be required to ensure phage replication for effective biocontrol in vivo. At the time of the trial the control birds in Farm B were phage positive despite having been negative one week earlier. There was no significant difference in the cecal Campylobacter counts between the treatment and control groups following treatment but a fall of 1.7 log 10 CFU/g was observed from that determined from birds collected the previous week (p = 0.0004). Campylobacter isolates from both farms retained sensitivity to the treatment phages. These trials demonstrated bacteriophages sourced from Queensland farms have the potential to reduce intestinal Campylobacter levels in market ready broiler chickens.

Campylobacter phages use hypermutable polyG tracts to create phenotypic diversity and evade bacterial resistance

“…Such population dynamics could consequently affect the use of Fletchervirus phages in broiler farms, which has been proposed as a promising intervention strategy to reduce Campylobacter loads before slaughter (Jane z and Loc-Carrillo, 2013). So far, studies of phage therapy that targets Campylobacter in chickens and at farm level have demonstrated varying efficiencies and phage-resistance development (Carvalho et al, 2010;Chinivasagam et al, 2020;Fischer et al, 2013;Ushanov et al, 2020). However, most of the phages used in these studies are not well characterized with respect to their receptors, and they have also not been sequenced.…”

Unveiling the Impact of Antibiotics and Alternative Methods for Animal Husbandry: A Review

“…The researcher found that the phage cocktails were effective at reducing Campylobacter levels in the market ready broilers. Nevertheless, there were a few birds in farm B showed a low phage titres, and the authors recommended to increase the treatment for over 24 h to ensure continuous phage replication for biocontrol of Campylobacter in-vivo [ 81 ]. Richards, et al [ 82 ] carried out a study in broiler chicken to determine the efficacy of a two-phage cocktail against C. jejuni .…”

Assessment of the Effectiveness of Pre-harvest Meat Safety Interventions to Control Foodborne Pathogens in Broilers: a Systematic Review

“…Still, in our review, research on the use of bacteriophages to control Campylobacter and Salmonella was scarce. One study carried out on a commercial farm showed no significant impact of bacteriophage application on Campylobacter loads [37], while for Salmonella, studies carried out on research institutions (controlled research setting) reported that this type of intervention caused significant reductions of the pathogen loads [55,56], which was not verified in a study held in a commercial setting [50]. While bacteriophages may be an alternative for the control of Campylobacter and Salmonella, one of the major disadvantages to widespread on farm bacteriophage application is due to the capacity of pathogens to become resistant to their bacteriophage, especially if the resistant bacteria can persist in the environment and replicate [11].…”