Use of phage phi 6 to inactivate Pseudomonas syringae pv. actinidiae in kiwifruit plants: in vitro and ex vivo experiments

Author(s)

Pinheiro, Larindja A. M. ^{[1, 2]} ; Pereira, Carla ^{[1, 2]} ; Esther Barreal, M. ^[3] ; Pablo Gallego, Pedro ^[3] ; Balcao, Victor M. ^{[1, 2, 4]} ; Almeida, Adelaide ^{[1, 2]}

Affiliation

^[1] Univ Aveiro, Dept Biol, Campus Univ Santiago, P-3810193 Aveiro - Portugal

^[2] Univ Aveiro, CESAM, Campus Univ Santiago, P-3810193 Aveiro - Portugal

^[3] Univ Vigo, Fac Biol, Dept Plant Biol & Soil Sci, Vigo 36310 - Spain

^[4] Univ Sorocaba, Lab Biofilms & Bacteriophages, PhageLab, BR-18023000 Sorocaba, SP - Brazil

• Document type: Journal article
• Source: Applied Microbiology and Biotechnology; v. 104, n. 3, p. 1319-1330, FEB 2020.
• Web of Science Citations: 0

Abstract

Over the last years, the global production and trade of kiwifruit has been severely impacted by Pseudomonas syringae pv. actinidiae (Psa), a phytopathogen that causes a disease in kiwifruit plants known as bacterial canker. The available treatments for this disease are still scarce, with the most common involving frequently spraying the orchards with disinfectants, copper-based bactericides and/or antibiotics. Moreover, these treatments should be avoided due to their high toxicity to the environment and promotion of bacterial resistance. Phage therapy may be an alternative approach to inactivate Psa. The present study investigated the potential application of the already commercially available bacteriophage (or phage) phi 6 to control Psa infections. The inactivation of Psa was assessed in vitro, using liquid culture medium, and ex vivo, using artificially contaminated kiwifruit leaves with two biovar 3 (a highly aggressive pathogen) strains (Psa CRA-FRU 12.54 and Psa CRA-FRU 14.10). In the in vitro experiments, the phage phi 6 was effective against both strains (maximum reduction of 2.2 and 1.9 CFU/mL for Psa CRA-FRU 12.54 and Psa CRA-FRU 14.10, respectively). In the ex vivo tests, the decrease was lower (maximum reduction 1.1 log and 1.8 CFU/mL for Psa CRA-FRU 12.54 and Psa CRA-FRU 14.10, respectively). The results of this study suggest that the commercially available phage phi 6 can be an effective alternative to control Psa infections in kiwifruit orchards. (AU)

• FAPESP's process: 18/05522-9 - PsaPhageKill - isolation, characterisation and use of lytic bacteriophages against Pseudomonas syringae PV. actinidiae to fight the cancer of kiwifruit: an efficient and ecofriendly alternative
• Grantee: Vitor Manuel Cardoso Figueiredo Balcão
• Support Opportunities: Scholarships abroad - Research