Bacteriophages LSA2308 and LSA2366 infecting drug-resistant Staphylococcus aureus: Isolation, characterization and potential application for milk safety

• Published in: Food science & technology Vol. 152; p. 112298
• Main Authors: Ma, Fei, Ning, Yu, Wan, Qingqing, Zou, Likou, Liu, Yuntao, Chen, Shujuan, Li, Jianlong, Zeng, Zhen, Yang, Yong, Chen, Hong, Zhou, Min, Liu, Shuliang, Li, Cheng, Liu, Aiping
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-12-2021
• Subjects: Bacteriophage; Biocontrol; Cocktail; Drug resistance; Staphylococcus aureus; Cocktail; Bacteriophage; Drug resistance; Staphylococcus aureus; Biocontrol
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2021.112298

Bacteriophages are considered a promising candidate for controlling food pathogens. In this study, we isolated and characterized S. aureus-infecting bacteriophages, and investigated their potential for antibiotic substitute and bacteriophage cocktail effect in Luria-Bertani (LB) broth and skim milk. Bacteriophages LSA2308 and LSA2366 possessing lytic activity against drug-resistant S. aureus were isolated. The latent period of LSA2308 and LSA2366 was approximately 20 and 10 min, with burst size of 407 and 258 PFU per infected cell, respectively. A combination of LSA2308 (or LSA2366) and 1/2 MIC ampicillin achieved better clearance of S. aureus CR003 in LB broth than treatment with either bacteriophage or ampicillin alone. Biocontrol with 105–107 PFU/mL LSA2308 or LSA2308/LSA2366 cocktail was effective in LB broth, whereas it was less active in skim milk. Compared with treatment using 105 or 106 PFU/mL bacteriophages, the bactericidal efficacy of 107 PFU/mL bacteriophages on single or mixed S. aureus strains in skim milk was the best at 4 and 25 °C, revealing a dose-dependent mode. Our study further expands the repertoire of bacteriophages infecting drug-resistant S. aureus, and provides insights into the control of S. aureus in milk production chain.
•Phages LSA2308 and LSA2366 with lytic activity against drug-resistant foodborne S. aureus were isolated.•Combination of phage and ampicillin achieved better biocontrol than treatment with either phage or ampicillin alone.•Phages LSA2308 and LSA2366 showed application potentials in milk production chain.