ADRIELE RODRIGUES DOS SANTOS

Título da Tese: INATIVAÇÃO FOTODINÂMICA MEDIADA PELOS CORANTES XANTENOS ROSA BENGALA E EOSINA CONTRA PATÓGENOS DE ORIGEM ALIMENTAR Salmonella Typhimurium E Staphylococcus aureus

Orientadora: Profa. Dra. Jane Martha Graton Mikcha

 Data da Defesa: 13/12/2019

RESUMO GERAL

INTRODUCTION. Foodborne diseases are a growing public health problem and are an 4 important cause of morbidity and mortality worldwide. Between 1998 – 2016, in the United 5 States, Salmonella spp. was responsible for 2.585 outbreaks of foodborne disease with 8.021 6 hospitalizations and Staphylococcus aureus for 671 outbreaks with 526 hospitalizations. In 7 Brazil, between 2009 – 2018, among the identified agents of foodborne disease, 11.3 % was 8 Salmonella spp. and 9.4 % was S. aureus, making them two important foodborne pathogens. 9 Preventing outbreaks of foodborne disease requires the control of microorganisms in the food 10 production chain. In this context, an efficient tool for inactivating microorganisms is 11 antimicrobial photodynamic therapy (aPDT), which is a promising and low-price technology 12 effective against a several types of foodborne bacteria. In a PDT, the inactivation of 13 microorganisms is caused by oxidative stress induced by the interaction of a light-excited 14 photosensitizer (PS) in the presence of molecular oxygen. The outcome from the action between 15 PS and visible light is irreversible damage to various molecular constituents of the cells (lipids, 16 proteins, enzymes, and DNA). This technique presents several advantages when compared with 17 the antimicrobials methods, showing to be efficient independently of the antimicrobial 18 resistance profile and to prevent further development of resistance even after several cycles of 19 treatment. Xanthene dyes have been considered good PSs to induce bacterial photoinactivation 20 due to their low price, high molar absorptivity, and high singlet oxygen quantum yield (ΦΔ). 21 The xanthene dyes rose bengal (RB) and eosin Y (EOS) have already proven to be effective 22 against bacteria, however, these dyes showed to be more effective against gram-positive 23 bacteria. This limitation can be overcomed using different organic salts such as potassium 24 iodide (KI). Some xanthene dyes are approved for use in drug, cosmetic, and medical 25 applications, and as food additives, while the safety of KI has been reported by Food and Drug 26 Administration (FDA). Several light sources with different wavelengths are available, including 27 the light-emitting diodes (LED). They are becoming a promising alternative to aPDT because 28 of greater flexibility in terms of irradiation time, a wide range of the visible electromagnetic 29 spectrum, including green light (490–570 nm region), and its low price. The mathematical 30 models, as response surface methodology (RSM), can be used to predict the best conditions for 31 inactivating microorganisms by aPDT. These models are valuable tools for applying this 32 technology in the food industry.

Artigos Publicados Vinculados a Tese:

 https://doi.org/10.3390/antibiotics9030125
https://doi.org/10.1111/jfs.12736
https://doi.org/10.3390/antibiotics8040211