Characterization of Streptococcus spp. strains associated with bovine mastitis: genotyping and antimicrobial resistance applied to epidemiological surveillance and infection control

• Grant number: 25/12756-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2025
• End date: August 31, 2026
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Preventive Veterinary Medicine
• Principal Investigator: Luisa Zanolli Moreno
• Grantee: Luísa Steiner Maia
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

Bovine mastitis is one of the leading causes of economic losses in dairy production, directly impacting milk quality, animal welfare, and productivity indicators on farms. Among the etiological agents associated with the infection, the genus Streptococcus stands out due to the high prevalence of its species, their dissemination potential, and their increasing resistance to antimicrobials. In this context, understanding the microbiological profiles of these strains is essential to support more effective control measures. This project aims to phenotypically and genotypically characterize Streptococcus spp. strains isolated from clinical and subclinical cases of bovine mastitis. To achieve this, complementary approaches will be employed, including identification by mass spectrometry (MALDI-TOF MS), confirmation by partial sequencing of the 16S rRNA gene, analysis of amplified fragment length polymorphism (SE-AFLP), and determination of antimicrobial resistance profiles through broth microdilution. The results will be correlated with epidemiological data from the source herds to identify patterns of occurrence, resistance profiles, and possible associations with clinical and epidemiological factors. It is expected that the findings will contribute to improving the microbiological diagnosis of mastitis and to the development of more targeted strategies for prevention and control. (AU)