Phage Biocontrol of <i>Pseudomonas aeruginosa</i> in Water

• Main Authors: Ari Kauppinen, Sallamaari Siponen, Tarja Pitkänen, Karin Holmfeldt, Anna Pursiainen, Eila Torvinen, Ilkka T. Miettinen
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: Viruses
• Subjects: <i>Pseudomonas aeruginosa</i>; bacteriophages; biocontrol; phage cocktail; water treatment
• Online Access: https://www.mdpi.com/1999-4915/13/5/928

Bacteriophage control of harmful or pathogenic bacteria has aroused growing interest, largely due to the rise of antibiotic resistance. The objective of this study was to test phages as potential agents for the biocontrol of an opportunistic pathogen <i>Pseudomonas aeruginosa</i> in water. Two <i>P. aeruginosa</i> bacteriophages (vB_PaeM_V523 and vB_PaeM_V524) were isolated from wastewater and characterized physically and functionally. Genomic and morphological characterization showed that both were myoviruses within the <i>Pbunavirus</i> genus. Both had a similar latent period (50–55 min) and burst size (124–134 PFU/infected cell), whereas there was variation in the host range. In addition to these environmental phages, a commercial <i>Pseudomonas</i> phage, JG003 (DSM 19870), was also used in the biocontrol experiments. The biocontrol potential of the three phages in water was tested separately and together as a cocktail against two <i>P. aeruginosa</i> strains; PAO1 and the environmental strain 17V1507. With PAO1, all phages initially reduced the numbers of the bacterial host, with phage V523 being the most efficient (>2.4 log₁₀ reduction). For the environmental <i>P. aeruginosa</i> strain (17V1507), only the phage JG003 caused a reduction (1.2 log₁₀) compared to the control. The cocktail of three phages showed a slightly higher decrease in the level of the hosts compared to the use of individual phages. Although no synergistic effect was observed in the host reduction with the use of the phage cocktail, the cocktail-treated hosts did not appear to acquire resistance as rapidly as hosts treated with a single phage. The results of this study provide a significant step in the development of bacteriophage preparations for the control of pathogens and harmful microbes in water environments.