A Novel Group of Promiscuous Podophages Infecting Diverse Gammaproteobacteria from River Communities Exhibits Dynamic Intergenus Host Adaptation
Por:
Cazares, Daniel, Cazares, Adrian, Figueroa, Wendy, Guarneros, Gabriel, Edwards, Robert A., Vinuesa, Pablo
Publicada:
1 ene 2021
Resumen:
Phages are generally described as species specific or even strain
specific, implying an inherent limitation for some to be maintained and
spread in diverse bacterial communities. Moreover, phage isolation and
host range determination rarely consider the phage ecological context,
likely biasing our notion on phage specificity. Here we isolated and
characterized a novel group of six promiscuous phages, named Atoyac,
existing in rivers and sewage by using a diverse collection of over 600
bacteria retrieved from the same environments as potential hosts. These
podophages isolated from different regions in Mexico display a
remarkably broad host range, infecting bacteria from six genera:
Aeromonas, Pseudomonas, Yersinia, Hafnia, Escherichia, and Serratia.
Atoyac phage genomes are similar to 42 kb long and highly similar to
each other, but not to those currently available in genome and
metagenome public databases. Detailed comparison of the phages'
efficiency of plating (EOP) revealed variation among bacterial genera,
implying a cost associated with infection of distant hosts, and between
phages, despite their sequence similarity. We show, through experimental
evolution in single or alternate hosts of different genera, that
efficiency of plaque production is highly dynamic and tends toward
optimization in hosts rendering low plaque formation. However,
adaptation to distinct hosts differed between similar phages; whereas
one phage optimized its EOP in all tested hosts, the other reduced
plaque production in one host, suggesting that propagation in multiple
bacteria may be key to maintain promiscuity in some viruses. Our study
expands our knowledge of the virosphere and uncovers bacteriumphage
interactions overlooked in natural systems.
IMPORTANCE In natural environments, phages coexist and interact with a
broad variety of bacteria, posing a conundrum for narrow-host-range
phage maintenance in diverse communities. This context is rarely
considered in the study of host-phage interactions, typically focused on
narrow-host-range viruses and their infectivity in target bacteria
isolated from sources distinct to where the phages were retrieved from.
By studying phage-host interactions in bacteria and viruses isolated
from river microbial communities, we show that novel phages with
promiscuous host range encompassing multiple bacterial genera can be
found in the environment. Assessment of hundreds of interactions in
diverse hosts revealed that similar phages exhibit different infection
efficiency and adaptation patterns. Understanding host range is
fundamental in our knowledge of bacterium-phage interactions and their
impact on microbial communities. The dynamic nature of phage promiscuity
revealed in our study has implications in different aspects of phage
research such as horizontal gene transfer or phage therapy.
Filiaciones:
Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
EMBL's European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Cambridge, United Kingdom
Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, United Kingdom
Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
Departamento de Genética y Biología Molecular, CINVESTAV IPN, Mexico City, Mexico
FAME, Flinders University, Adelaide, SA, Australia
Gold, Green Published
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