Banca de QUALIFICAÇÃO: PAULA OLIVEIRA DUARTE

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE: PAULA OLIVEIRA DUARTE
DATA: 30/01/2026
HORA: 14:00
LOCAL: DMV08
TÍTULO:

Assessment of on-farm culture tool for identifying mastitis-causing agents in order to reduce indiscriminate use of antimicrobials on the farm

PALAVRAS-CHAVES:

Mastitis, antimicrobial resistance, AMR.

PÁGINAS: 50
GRANDE ÁREA: Ciências Agrárias
ÁREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
ESPECIALIDADE: Doenças Infecciosas de Animais
RESUMO:

diagnosis.

Bovine mastitis is a highly prevalent, multifactorial disease, considered one of the diseases with the greatest economic impact on dairy herds worldwide. In Brazil, dairy farming is one of the most competitive globally, and the economic impacts associated with mastitis represent a significant challenge for the entire milk production chain. Among the most frequently isolated pathogens in cases of mastitis are Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, Escherichia coli, and Klebsiella pneumoniae, all recognized for their ability to cause mammary inflammation and impact milk production. Effective mastitis management requires rapid and accurate case identification, followed by accurate diagnosis, careful selection of therapeutic options, and the adoption of preventive measures targeting the herd's specific risk factors associated with exposure to the microorganisms that cause the disease. This study aimed to evaluate the diagnostic efficacy of the Mamitest chromogenic medium for identifying bovine mastitis pathogens by analyzing parameters such as accuracy, diagnostic sensitivity (DSe), diagnostic specificity (DSp), and the level of agreement using Cohen’s kappa index. To determine if the chromogenic test is a viable and efficient alternative to traditional methods, two tests were performed: (1) classical microbiological culture, following the National Mastitis Council (NMC) guidelines, and (2) culture on a quad-plate chromogenic medium for the rapid identification of mastitis-causing microorganisms. A total of 632 milk samples were evaluated using two diagnostic methods, and the most frequently isolated species in this study were coagulase-negative Staphylococci (141), followed by Streptococcus agalactiae (123) and Staphylococcus aureus (121). The performance of Mamitest compared to NMC was determined through calculations conducted in R software using the “epiR” package, in order to obtain the  sensitivity and specificity values. Preliminary results indicated high diagnostic specificity (DSp) for S. aureus (96%) and S. agalactiae (91%). These indices demonstrate the test's high reliability in preventing false-positive results, which is crucial for initial management given the impact of these contagious pathogens on dairy herd health. It was also possible to observe high specificity for the Gram-negative group (97%), in order to assist the producer in the management and observation of these animals without prior antibiotic intervention. Therefore, further analyses are being conducted to better support these data and to improve the planning of positive impacts on farm routine and the optimization of diagnostic processes.

MEMBROS DA BANCA:
Externo ao Programa - MAYSA SERPA GONCALVES - DME/FCS (Membro)
Externo à Instituição - MARCOS BRYAN HEINEMANN - USP (Membro)
Interno - GLAUCIA FRASNELLI MIAN (Membro)
Presidente - ELAINE MARIA SELES DORNELES (Membro)
Externo à Instituição - DIRCÉIA APARECIDA DA COSTA CUSTÓDIO - UFLA (Suplente)
Interno - ALESSANDRO DE SA GUIMARAES - EMBRAPA (Suplente)