Phage cocktails for the prevention of bacterial infections causing environmental mastitis in cattle herds

• Grant number: 25/02561-7
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE
• Start date: September 01, 2025
• End date: August 31, 2027
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Luciano Lopes Queiroz
• Grantee: Luciano Lopes Queiroz
• Associated researchers: Bruno Tirulli Fonseca
• Associated research grant: 22/10657-6 - Bacteriophages for the treatment of mastitis in cattle, AP.PIPE

Abstract

Several bacterial species possess multiple antibiotic resistance mechanisms, making the treatment of their infections in humans and animals increasingly challenging. In this context, the use of bacteriophages, or phages-viruses that infect bacteria-has emerged as a promising alternative to antibiotics, attracting growing interest for medical and veterinary applications. Brazil, as the fifth-largest milk producer in the world and home to the second-largest commercial cattle herd, extensively uses antibiotics in dairy farming. This excessive use leads to additional costs for producers and contributes to the emergence of resistant bacteria. Mastitis is a major concern for dairy producers-an inflammation of the mammary gland that causes physical and chemical changes in milk, which more than 130 different microorganisms can cause. The main bacterial species involved in mastitis include Staphylococcus aureus, coagulase-negative Staphylococcus, Streptococcus agalactiae, Mycobacterium bovis, and Escherichia coli. This project aims to continue the development of bacteriophage-based products for the prevention of mastitis in cattle, focusing on formulation development, scaling up, and testing in relevant environments. During Phase 1, more than 80 bacteriophages capable of infecting Staphylococcus aureus, Klebsiella pneumoniae, Enterobacter asburiae, and Escherichia coli were isolated and characterized. The characterization included host interaction assays, stability testing, infection spectrum analysis, and genomic sequencing. Based on these results (PIPE Phase 1), 23 phages with a broad infection spectrum were selected, and two cocktails containing three phages each were formulated to target K. pneumoniae and E. coli, the bacteria responsible for environmental mastitis. In Phase 2, the goal is to further develop the formulations and conduct tests in simulated, relevant, and operational environments to enable scaling up and commercialization of the technology. By the end of the project, the products will progress from a Technology Readiness Level (TRL) of 4 to 7. Phase 2 will not only advance the development of an innovative product for mastitis prevention but also validate the use of bacteriophages under field conditions, contributing to animal health and the sustainability of milk production. (AU)