Fate of phage P22 in tropical waters

NANDINI SHOME; CRUZ, MERCEDES CECILIA; RAJAL, VERONICA BEATRIZ; MARZINELLI, EZEQUIEL; MINJI KIM; TAY, MARTIN; STEFAN WUERTZ

Salta

Simposio; III Simposio Latinoamericano de Virología Ambiental (III-SILVA 2016); 2016

Environmental fate and transport studies of human viruses that take into acount the role of biofilms are few and far between. Here we studied the fate of bacteriophage P22, a surrogate of water borne DNA viruses, in replicate outdoor mesocosm flumes under conditions simulating tropical urban waterways. Two model bacteria, namely, Pseudomonas aeruginosa (environmental isolate) and Enterococcus faecalis (ATCC 47077), and the bacteriophages P22 (ATCC 97541) and GA (donated) were added to open channel flumes with partial recirculation (Reynolds number ≈350), and monitored for 20 d. Most of the infectious phages had disappeared from the water phase by the end of week 1. Detection of nucleic acids of P22 in the water exceeded detection of viable units as expected. The decay rates of P22 as estimated using a first order decay model were 0.8 d-1 for viable populations, and no decay was observed for phage DNA. A very small proportion of phages that had settled on the benthic biofilm remained viable for two weeks. Comparing the concentrations of P22 in water and biofilm, it appears that although phage particles stayed mostly in the water phase, viability was enhanced upon contact with the autochthonous biofilm population.