Evolution of the in vitro antimicrobial susceptibility of Staphylococcus spp. isolated from milk of herd cows subjected to unconventional mastitis treatment

• Grant number: 20/09470-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2020
• End date: October 31, 2022
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Products of Animal Origin Inspection
• Principal Investigator: Luiz Francisco Zafalon
• Grantee: Larissa Cristina Brassolatti
• Host Institution: Embrapa Pecuária Sudeste. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA). Ministério da Agricultura, Pecuária e Abastecimento (Brasil). São Carlos , SP, Brazil

Abstract

Mastitis is recognized as one of the main diseases in dairy cattle, as it causes great economic losses due to the reduction of milk production and changes in the quality of the product. The disease is caused mainly by bacteria of the genus Staphylococcus spp., Which have the ability to remain in the herd for long periods, causing persistent chronic conditions. In herds with organic management, producers and technicians use unconventional ways to treat and control the disease, such as homeopathy. However, the possible changes in the susceptibility profiles of microorganisms are unknown when a herd ceases to be subjected to this type of treatment. Thus, this study aims to characterize the occurrence and profiles of in vitro antimicrobial resistance in Staphylococcus spp., Isolated from milk of herd cows with a history of mastitis treatment with homeopathy. Milk samples will be obtained to investigate the infectious etiology of mastitis caused by Staphylococcus spp. and somatic cell count. Milk yields from cows in the herd will also be quantified and the relationship between isolated microorganisms with somatic cell count and milk production from cows treated and not treated with homeopathy will be established. The bacteria identified as belonging to the Staphylococcus genus will be subjected to confirmatory tests for the genotypic identification of species and in vitro susceptibility tests will be carried out using the disc-diffusion technique in microorganisms isolated from milk.