Gamma-irradiated Campylobacter spp. as an innovative vaccine prototype for poultry

Campylobacter spp. is a leading cause of foodborne disease worldwide [1]. According to EFSA, poultry and poultry products account for approximately 20–30% of human campylobacteriosis cases, underscoring the central role of the poultry production chain as the primary reservoir of the pathogen. The high prevalence of Campylobacter in poultry and the limited efficacy of current on-farm control measures underline the need for alternative strategies. Although vaccination represents a promising strategy, no commercial vaccines are currently available due to the antigenic complexity of the pathogen [2]. This study proposes an innovative vaccination strategy based on Campylobacter strains inactivated by gamma irradiation. This technology employs high-energy ionizing radiation capable of inducing irreversible damage to bacterial DNA, thereby preventing replication while preserving the integrity of the key antigenic structures necessary for immune stimulation. The experimental design involved the selection of representative C. jejuni and C. coli strains, which were exposed to increasing doses of gamma irradiation (250 Gy, 500 Gy, 750 Gy, 1000 Gy, 1500 Gy, 2000 Gy) to determine the D10 value, defined as the dose required to achieve a 90 % reduction in bacterial load [3]. The minimum dose required for complete inactivation was subsequently calculated based on the initial bacterial concentration. Irradiated strains were then evaluated for residual viability, metabolic activity and ATP production to assess the effectiveness of inactivation and the preservation of functional cellular components. This approach aims to support the development of a safe and effective vaccine prototype, with potential applications in the poultry sector and implications for food safety and public health.