Banca de DEFESA: PAULA OLIVEIRA DUARTE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE: PAULA OLIVEIRA DUARTE
DATA: 29/06/2026
HORA: 13:30
LOCAL: DMV08
TÍTULO:

Diagnosis of bovine mastitis: performance of microbiological methods and strategies for mitigating the use of antimicrobials

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.

Considered the largest economic burden on dairy farming, mastitis is a complex and highly prevalent pathology that threatens the sustainability of the competitive Brazilian dairy sector. Controlling the disease depends on a robust strategy, encompassing rapid detection, accurate diagnosis, and the implementation of customized therapeutic and preventive protocols to mitigate the pressure from common pathogens such as Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, as well as Escherichia coli and Klebsiella pneumoniae. This study was structured in two main stages. First, the diagnostic efficacy of the Mamitest chromogenic medium in identifying bovine mastitis-causing pathogens was evaluated, using the classical microbiology recommended by the National Mastitis Council (NMC) as a reference (gold standard). In a second phase, the accuracy of the results obtained using chromogenic and classical culture techniques was analyzed, this time establishing MALDI-TOF technology as the comparative gold standard. The initial analysis encompassed 632 milk samples, identifying the most frequent pathogens as coagulase-negative staphylococci (141), followed by Streptococcus agalactiae (123) and Staphylococcus aureus (121). In the subsequent stage, a sample was composed of 535 isolates, which were subjected to diagnostic validation by comparing the results obtained previously with MALDI-TOF technology, used as the gold standard. For this, diagnostic sensitivity (DSe), diagnostic specificity (DSp), and accuracy of the isolated pathogens were calculated in the two stages of the work. It should be noted that, in this process, classical culture presents high reliability, demonstrating a minimum sensitivity of 80% and a specificity of at least 71% for the Gram-positive bacteria group, reaching up to 97% for S. aureus. In parallel, microbiological culture, validated by both classical methods and MALDI-TOF technology, exhibited results equivalent to or superior to the data analyzed previously. In conclusion, the use of MALDI-TOF as the gold standard allowed for a clear delimitation of the diagnostic scope of each evaluated technique. The data demonstrate that, although they have proven efficacy, these methods possess specificities that must be taken into account in routine laboratory work. This clear diagnosis is the foundation for an effective strategy to mitigate the use of antimicrobials, since, by understanding the performance of each test against the gold standard, the healthcare team can base their therapeutic and management decisions on technical criteria and safety standards, using laboratory support as a strategic ally, within a clinical practice based on evidence and technical analysis.

MEMBROS DA BANCA:
Interno - ALESSANDRO DE SA GUIMARAES - EMBRAPA (Suplente)
Externo à Instituição - ANA FLAVIA MINUTTI - UFLA (Membro)
Externo à Instituição - ANDREY PEREIRA LAGE - UFMG (Suplente)
Interno - CARINE RODRIGUES PEREIRA (Membro)
Externo à Instituição - MONICA MARIA OLIVEIRA PINHO CERQUEIRA - UFMG (Membro)
Presidente - ELAINE MARIA SELES DORNELES (Membro)