Banca de DEFESA: ELIZABETH SIMÕES DO AMARAL ALVES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ELIZABETH SIMÕES DO AMARAL ALVES
DATE: 18/09/2025
TIME: 08:00
LOCAL: Online via Google Meet
TITLE:

DEVELOPMENT OF AN ANTIBACTERIAL NANOTECHNOLOGICAL PROCESS AND PRODUCT CONTAINING A MULTIPLE NANOEMULSION WITH ESSENTIAL OIL FOR MASTITIS CONTROL

KEY WORDS:

Animal Health, Nanotechnology, Dairy Farming, Phytotherapy, Dipping, Food Safety.

PAGES: 226
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUMMARY:

Mastitis is the leading disease affecting dairy herds and represents the primary reason for antimicrobial usage. This contributes to the presence of antibiotic residues in milk and promotes antimicrobial resistance, posing risks to public health. In this context, the urgent development of effective and safe antimicrobial alternatives is essential, particularly those compatible with organic production systems. In this framework, this thesis aimed to develop and validate an antibacterial nanotechnological product for teat disinfection before and after milking (pre- and post-dipping), with anti-mastitic activity. Initially, a technological prospecting was conducted using patent databases to identify trends and gaps in innovations related to mastitis control. The results revealed a predominance of inventions focused on synthetic antimicrobials, mainly originating from the United States and developed by private companies, with emphasis on prophylactic and therapeutic applications. A notable gap was identified in technologies based on natural products, highlighting an opportunity in this segment. Accordingly, a production process was developed using a multiple water/oil/water nanoemulsion containing oregano essential oil (Origanum vulgare), employing a high-energy emulsification method. Two nanoemulsions were formulated, differing in the type of fixed oil used: mineral oil (NEM-MO) and soybean oil (NEM-SO). Organoleptic tests, centrifugation, and thermal stress confirmed the homogeneity of the dispersion phases. Physicochemical characterizations indicated colloidal system stability, with vesicle sizes measured at 83.08 ± 0.76 nm and 138.70 ± 0.26 nm, polydispersity index (PDI) values of 0.21 and 0.22, and zeta potential of -11.70 ± 0.61 mV for NEM-MO and NEM-SO, respectively. Antibacterial efficacy was assessed through contact time exposure tests at 15, 30, 60, and 300 seconds against mastitis isolates: Staphylococcus aureus, coagulase-positive Staphylococcus, and Escherichia coli. The antibacterial performance of both nanoemulsions was similar, with S. aureus being more sensitive and E. coli more resistant. Consistent antibacterial activity was observed at 60 seconds, with 300 seconds being the most effective exposure time. Shorter durations were ineffective, indicating a time-dependent response. Notably, compared to the control, the results were promising—for instance, at 300 seconds, the control was only 13.33% more effective against S. aureus. In conclusion, the nanoemulsions demonstrated efficacy in inhibiting major mastitis pathogens, presenting a natural and safe alternative for teat hygiene management, especially in organic herds. Furthermore, the use of natural antiseptics is encouraged, as it contributes to reducing conventional antimicrobial usage, minimizing residue presence in milk, and promoting public health and food safety. This research advances sustainable solutions for mastitis control, reinforcing animal health, food security, and antimicrobial resistance mitigation.

COMMITTEE MEMBERS:
Presidente - PABYTON GONCALVES CADENA
Externa ao Programa - 3309515 - ANDREA PAIVA BOTELHO LAPENDA DE MOURA - UFRPEExterno à Instituição - JOÃO MANOEL DA SILVA - IFAl
Externa à Instituição - MARIA DO CARMO DE BARROS PIMENTEL - UFPE
Externo à Instituição - OMER CAVALCANTI DE ALMEIDA