Profile of etiologic agents causing clinical mastitis and antimicrobial use in dairy herds

• Grant number: 13/22286-3
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2014
• End date: October 31, 2017
• Field of knowledge: Agronomical Sciences - Veterinary Medicine
• Principal Investigator: Marcos Veiga dos Santos
• Grantee: Tiago Tomazi
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 13/07914-8 - FoRC - Food Research Center, AP.CEPID
• Associated scholarship(s): 15/17516-5 - Detailed characterization of mastitis-causing pathogens previously identified as "other Streptococcal species" over time, BE.EP.DR

Abstract

This study aims to determine the etiologic profile and antimicrobial susceptibility of clinical mastitis pathogens, and to describe the qualitative and quantitative aspects associated with antimicrobial drug usage for treatment of mastitis in dairy herds. The study will be performed by development of three experiments: Experiment 1 - Determination of etiologic profile of clinical mastitis in dairy herds; Experiment 2 - Quantification of antimicrobial drug usage for treatment of mastitis; and Experiment 3 - Economic approach and evaluation of risk factors related to a program of on farm microbiological culture. For experiments 1 and 2, milk samples and data related with antimicrobial use will be collected from 15 dairy herds during 12 months. Data will be collected to determine the prevalence, incidence, clinical mastitis causative pathogens, score of severity, treatment protocols and antimicrobial drugs used, estimation of milk disposal and rates of recurrence and new intramammary infections. Isolates diagnosed as Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis and Escherichia coli will be analyzed for minimum inhibitory concentration and genotypically analysed by PCR-random amplification of polymorphic DNA (RAPD-PCR). The quantification of antimicrobial will be developed by estimating the defined daily dose of antimicrobial drugs used for treatment of mastitis and dry cow therapy. In experiment 3, lactating cows from three dairy herds will be randomly assigned into two treatment groups to determine risk factors related to on farm microbiological culture program, and for economic approach of this program as compared with immediate treatment of cows with clinical mastitis.

Scientific publications

(5)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

TOMAZI, TIAGO; DE SOUZA FILHO, ANTONIO FRANCISCO; HEINEMANN, MARCOS BRYAN; DOS SANTOS, MARCOS VEIGA. Molecular characterization and antimicrobial susceptibility pattern of Streptococcus agalactiae isolated from clinical mastitis in dairy cattle. PLoS One, v. 13, n. 6, JUN 21 2018. (13/22286-3, 14/17411-6, 15/10332-6)

FREU, GUSTAVO; TOMAZI, TIAGO; FILHO, ANTONIO F. S.; HEINEMANN, MARCOS B.; DOS SANTOS, MARCOS, V. Antimicrobial Resistance and Molecular Characterization of Staphylococcus aureus Recovered from Cows with Clinical Mastitis in Dairy Herds from Southeastern Brazil. ANTIBIOTICS-BASEL, v. 11, n. 4, p. 11-pg., 2022-04-01. (13/22286-3, 14/17411-6, 15/10332-6)

TOMAZI, T.; COURA, F. M.; GONCALVES, J. L.; HEINEMANN, M. B.; SANTOS, M. V.. Antimicrobial susceptibility patterns of Escherichia coli phylogenetic groups isolated from bovine clinical mastitis. JOURNAL OF DAIRY SCIENCE, v. 101, n. 10, p. 9406-9418, OCT 2018. (13/22286-3, 14/17411-6, 15/10332-6)

TOMAZI, TIAGO; FREU, GUSTAVO; ALVES, BRUNA GOMES; DE SOUZA FILHO, ANTONIO FRANCISCO; HEINEMANN, MARCOS BRYAN; DOS SANTOS, MARCOS VEIGA. Genotyping and antimicrobial resistance of Streptococcus uberis isolated from bovine clinical mastitis. PLoS One, v. 14, n. 10, OCT 22 2019. (15/10332-6, 13/22286-3, 14/17411-6)

MARTINS, LARISSA; GONCALVES, JULIANO L.; LEITE, RENATA F.; TOMAZI, TIAGO; RALL, VERA L. M.; SANTOS, V, MARCOS. Association between antimicrobial use and antimicrobial resistance of Streptococcus uberis causing clinical mastitis. JOURNAL OF DAIRY SCIENCE, v. 104, n. 11, p. 12030-12041, NOV 2021. (13/23613-8, 18/23040-1, 14/17411-6, 13/22286-3)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

TOMAZI, Tiago. Etiological and molecular profile of pathogens causing clinical mastitis, and antimicrobial use in dairy herds. 2017. Doctoral Thesis - Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) Pirassununga.