UV-A-laser or UV-C irradiation combined with bacteriophage treatment to combat Campylobacter jejuni on chicken breast fillets

In this study the application of UV-A-laser (343 nm) or UV-C (254 nm) irradiation combined with a bacteriophage treatment was investigated to reduce Campylobacter jejuni on the surface of chicken breast fillet. At radiant exposure of 26.2 J/cm2 the UV-A-laser irradiation inactivated 1.8 +/- 0.1 log10 CFU/piece of C. jejuni PT14, and 2.0 +/- 0.1 log10 CFU/piece when phage C11 was applied additionally with a multiplicity of infection (MOI) of 1. Using UV-C at radiant exposure of 26.2 J/cm2, an inactivation of 0.5 +/- 0.1 log10 CFU/piece of C. jejuni PT14 was achieved when irradiating alone and of 1.0 +/- 0.1 log10 CFU/piece when combined with phage C11 treatment at MOI of 100. Inactivation of C. jejuni PT14 by phage C11 treatment combined either with the UV-A-laser or the UV-C irradiation was found to be additive. The sequence of treatments, i.e., UV irradiation followed by phage treatment and vice versa, affected the inactivation level only to minor extent.