Bacteriophage Therapy to Reduce Colonization of Campylobacterjejuni in Broiler Chickens before Slaughter.

Daniela D’Angelantonio,Giuseppe Aprea,Philippa Connerton,Arianna Boni,Diana Neri,Francesco Pomilio,Elisabetta Di Giannatale,Silvia Scattolini,Ian Connerton,Gabriella Di Serafino,Giacomo Migliorati

doi:10.3390/v13081428

Abstract

Campylobacteriosis is the most commonly reported gastrointestinal disease in humans. Campybacter jejuni is the main cause of the infection, and bacterial colonization in broiler chickens is widespread and difficult to prevent, leading to high risk of occurrence in broiler meat. Phage therapy represents an alternative strategy to control Campylobacter in poultry. The aim of this work was to assess the efficacy of two field-isolated bacteriophages against experimental infections with an anti-microbial resistant (AMR) Campylobacter jejuni strain. A two-step phage application was tested according to a specific combination between chickens’ rearing time and specific multiplicities of infections (MOIs), in order to reduce the Campylobacter load in the animals at slaughtering and to limit the development of phage-resistant mutants. In particular, 75 broilers were divided into three groups (A, B and C), and phages were administered to animals of groups B and C at day 38 (Φ 16-izsam) and 39 (Φ 7-izsam) at MOI 0.1 (group B) and 1 (group C). All broilers were euthanized at day 40, and Campylobacter jejuni was enumerated in cecal contents. Reductions in Campylobacter counts were statistically significant in both group B (1 log10 colony forming units (cfu)/gram (gr)) and group C (2 log10 cfu/gr), compared to the control group. Our findings provide evidence about the ability of phage therapy to reduce the Campylobacter load in poultry before slaughtering, also associated with anti-microbial resistance pattern.

Highlights

Introduction iationsCampylobacter is the most commonly reported gastrointestinal bacterial pathogen in humans in the European Union (EU) since 2005, with 220,682 confirmed cases of Campylobacteriosis in 2019 [1]
Campylobacter spp., in particular Campylobacter jejuni (C. jejuni) and Campylobacter coli (C. coli), are ubiquitous in nature, and their niche seems to be the intestinal mucosa of warm-blooded hosts [2,3], especially those of avian species
The physical response of chickens administered with the C. jejuni field strain and/or bacteriophages was indistinguishable from that of the control birds in terms of no apparent loss of appetite, no reduction in weight gain, no alteration in locomotion, and no diarrhea or respiratory distress

Summary

Introduction

Campylobacter is the most commonly reported gastrointestinal bacterial pathogen in humans in the European Union (EU) since 2005, with 220,682 confirmed cases of Campylobacteriosis in 2019 [1]. The natural bacterial colonization is mainly associated with horizontal transmission at the farm level, and to a lesser extent to vertical transmission [4], with a mean prevalence in the EU of 71.2% of broiler batches [5]. While Campylobacter in chickens does not cause any visible symptoms, in humans some strains can lead to severe disease, with clinical signs like fever, headache, abdominal pain and diarrhea, nausea, and vomiting. Most cases of Campylobacteriosis are self-limiting, but there is the potential of post-infection complications such as Licensee MDPI, Basel, Switzerland.

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