Isolation and genomic characterization of local lysogenic and lytic podophages against Pseudomonas aeruginosa
Jorrico Suelto II*, Edelca Panisales, Timothy Mendoza, Ron Leonard Dy
- National Institute of Molecular Biology and Biotechnology
Jorrico Suelto II (jdsuelto@up.edu.ph)
Pseudomonas aeruginosa is a ubiquitous and opportunistic bacteria known to inhabit diverse environments and has been frequently associated with multidrug-resistant infections in immunocompromised individuals. In nature, bacteriophages serve as natural predators of P. aeruginosa and growing interest in phages has risen over the years not only for their potential to combat antimicrobial resistance but also to serve as tools for studying P. aeruginosa. In this study, 20 phages against P. aeruginosa were isolated from wastewater from the Philippines. All phages were evaluated and four were selected for further analysis due to their broad host range, unique and uniform plaque morphology, high efficiency of plating, and unique restriction digest profiles which altogether maximize the probability that each phage is unique before sequencing. Phages S4C1C (PK), S6C4V (PO), and S9C2V (PT) belonged to the genus Jamesmcgillvirus, whereas S7C1C (PE) belonged to the genus Kochitakasuvirus. Both genera are members of the Podoviridae family of phages and are among the poorly represented phages in genome databases with only 2 representative phages known according to the International Committee on Taxonomy of Viruses (ICTV). The whole genomes of the four podophages have high degrees of similarities (~95%) to their closest homologue and follow similar genome organizations and sizes. Although both phages S4C1C (PK) and S6C4V (PO) do not appear to possess integrases or recombinases in their genome, both caused lysogenic conversion of P. aeruginosa suggesting they are likely temperate phages. These phages may be developed as genetic tools or engineered for targeted genetic delivery of genes in P. aeruginosa. Whereas, phages S7C1C (PE) and S9C2V (PT) are better candidates for use as antimicrobials as these were found to be strictly virulent and had no annotated integrases on their genomes. Finally, this study exemplifies the abundance of phages in the Philippines which may be employed as genetic tools or developed as antimicrobial agents of P. aeruginosa.