ZOONOSI, RESISTENZE ANTIMICROBICHE E INNOVAZIONE NELL¿ALLEVAMENTO DEL BOVINO DA LATTE: APPROCCI INTEGRATI SECONDO IL PARADIGMA ONE HEALTH

The intensive use of antibiotics in human and veterinary medicine has promoted the global spread of antimicrobial resistance (AMR), with serious implications for public health and the sustainability of livestock farming. In this context, zoonotic pathogens such as S.aureus and S.agalactiae represent a complex threat, capable of crossing species barriers and spreading resistance genes. This thesis adopts an integrated One Health approach to analyse the spread of resistant bacterial strains in milk, assess the milk resistome, and propose innovative solutions for the control of contagious mastitis. To evaluate the risk associated with zoonotic pathogens and antimicrobial resistance genes, epidemiological and genomic analyses of bacterial strains were integrated with metagenomic studies of milking filters, aimed at monitoring the spread of AMR. Furthermore, the effectiveness and applicability of antimicrobial elastomers to produce milking liners were assessed, with the goal of reducing the transmission of contagious pathogens during milking. The introduction of these elastomers for milking significantly reduced the transmission of contagious pathogens, contributing to a decrease in mastitis incidence. Epidemiological analysis of over 36,000 isolates enabled the identification of resistance patterns and their distribution in S.aureus and S.agalactiae. Furthermore, the application of metagenomic techniques to milking filters revealed a widespread presence of AMR genes, confirming the role of the farm environment in the circulation of resistance. Meanwhile, the adoption of advanced diagnostic protocols improved monitoring of the herd’s health status, enabling targeted interventions and a reduction in antibiotic use. These results demonstrate the effectiveness of an integrated and innovative approach in managing bovine infections, preventing the spread of AMR, and promoting public, animal, and environmental health according to the principles of the One Health paradigm. The implications of this study suggest the possibility of implementing replicable models of surveillance and health intervention in dairy farm, contributing concretely to the global fight against AMR.