Bacteriophage PCSE1 as a Potential Strategy Against Salmonella Enteritidis in Liquid Egg Products

resumo

Background/Objectives: The consumption of liquid egg products is rising. While thermal pasteurization improves safety and shelf life, it can affect product quality. Furthermore, egg products continue to cause many foodborne illnesses, especially those caused by Salmonella enterica subspecies enterica serovar Enteritidis (Salmonella Enteritidis). Bacteriophages (or phages) are an effective alternative to specifically fight foodborne bacteria. This study aimed to evaluate (i) the stability of phage vB_SeEM_UALMA_PCSE1 (PCSE1) under different conditions of temperature and pH; (ii) the effect of multiplicity of infection (MOI) and temperature on phage efficacy; (iii) the bactericidal effect of phage PCSE1 against S. Enteritidis in liquid whole eggs compared to thermal pasteurization; and (iv) the effect of both treatments on the physicochemical and functional properties of liquid whole eggs. Methods: For this, stability tests, bacterial growth inhibition assays in culture media and liquid eggs, and physicochemical and functional analyses were conducted. Results: Phage PCSE1 was (i) stable at pH 7 and 8, and at 4, 25, and 37 degrees C for 56 days; (ii) effectively prevented S. Enteritidis growth in TSB (reduction of 1.8, 4.5, and 4.5 log colony-forming units (CFU)/mL at 4, 10, and 25 degrees C, respectively, relative to the bacterial control); (iii) controlled S. Enteritidis in liquid whole eggs at 25 degrees C (reduction of 5.8 log CFU/mL relative to the bacterial control) comparable to pasteurization (reduction of 5.2 log CFU/mL); and (iv) preserved eggs' properties, contrarily to pasteurization. Conclusions: These findings suggest PCSE1 is a promising strategy to fight S. Enteritidis in liquid egg products, though further studies on shelf-life are needed.

palavras-chave

PULSED ELECTRIC-FIELDS; FUNCTIONAL-PROPERTIES; TYPHIMURIUM; RESISTANCE; COCKTAIL; FOODS; HEAT

categoria

Infectious Diseases; Pharmacology & Pharmacy

autores

Braz, M; Pereira, C; Matos, G; Saraiva, JA; Freire, CSR; Almeida, A

Grupos

G1 - Materiais Porosos e Nanossistemas
G4 - Materiais Renováveis e Economia Circular

Projectos

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

agradecimentos

This work was supported by FCT/MECTES (PIDDAC) who provide financial support to UID Centro de Estudos do Ambiente e Mar (CESAM) + LA/P/0094/2020, CICECO-Aveiro Institute of Materials (UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020), UIDP/50011/2020 (DOI 10.54499/UIDP/50011/2020) and LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020)) and to the LAQV-REQUIMTE research unit (UID/50006-Laboratorio Associado para a Quimica Verde-Tecnologias e Processos Limpos) through national funds. FCT also supported this work through the attribution of a PhD grant to Marcia Braz (DOI 10.54499/2020.06571.BD) and research contracts to Carla Pereira and Carmen S. R. Freire (DOI 10.54499/CEECIND/03974/2017/CP1459/CT0022 and DOI 10.54499 /CEECIND/00464/2017/CP1459/CT0033, respectively).