Preliminary study on the effectiveness of detergent and sanitiser products on Arcobacter butzleri strains

Arcobacter butzleri is a zoonotic pathogen mainly isolated from poultry industry. Despite the use of disinfection procedures, numerous studies have documented the prolonged presence of A. butzleri in food processing environments. This study investigates the susceptibility of A. butzleri isolated from poultry carcasses and slaughter equipment to the most used commercial disinfectants and detergents in food processing plants for surface disinfection and organic matter removal. Thirty-one strains of A. butzleri isolated from a chicken slaughterhouse together with the reference strains A. butzleri LMG10828T, Escherichia coli ATCC35150 and Staphylococcus aureus ATCC25923 were evaluated for the susceptibility test. The detergents used are neutral, slightly alkaline, and alkaline. Disinfectants used include peracetic acid, peracetic acid combined with hydrogen peroxide, quaternary ammonium salts, active chlorine, and finally amine-based disinfectants. The analysis was carried out using the agar disk diffusion method, the measurement was made in millimeters from the inhibition front of the commercial products to the edge of the disk. Considering the A. butzleri strains, 3% peracetic acid and 0.5% peracetic acid with hydrogen peroxide showed the greatest inhibition (14.7 and 12.6 mm respectively). In comparison, A. butzleri strains with 0.6% quaternary ammonium compound, 1.25% amine and lastly 9.5% active chlorine disinfectant produced an inhibition zone of 3 mm. Regarding alkaline and neutral detergents, no susceptibility was observed in most cases, except S. aureus for which 5.5% neutral detergent produced an inhibition zone (6.3 mm). Statistically significant findings have been identified about the disinfectants employed, without the emergence of generally more or less resistant strains from the totality tested. This study highlighted the variable efficacy of different formulations against A. butzleri. Based on these initial results, it appears that the micro-organism is more susceptible to peracetic acid than to other disinfectants. To better understand the mechanisms of resistance, future RNA sequencing analyses will be performed to understand the genes and pathways involved. Given the persistence of A. butzleri, it is necessary to establish appropriate disinfecting procedures to reduce the presence of the pathogen in food-processing plants.