Open Access Short report

Phenotypic and genotypic variations within a single bacteriophage species

Pieter-Jan Ceyssens1, Thea Glonti2, ndrew M Kropinski34, Rob Lavigne1*, Nina Chanishvili2, Leonid Kulakov5, Nino Lashkhi2, Marina Tediashvili2 and Maya Merabishvili26

Author Affiliations

1 Laboratory of Gene Technology (LoGT), Katholieke Universiteit Leuven, Kasteelpark Arenberg 21 bus 2462, B-3001 Leuven, Belgium

2 Eliava Institute of Bacteriophage, Microbiology and Virology (EIBMV), 3 Gotua Street, 0160 Tbilisi, Georgia

3 Laboratory for Foodborne Zoonoses, Public Health Agency of Canada, 110 Stone Road West, Guelph, ON, N1G 3W4, Canada

4 Department of Molecular & Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada

5 School of Biological Sciences, The Queen's University of Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland

6 Laboratory for Molecular and Cellular Technology (LabMCT), Burn Wound Center, Queen Astrid Military Hospital, Bruynstraat 1, 1120 Brussels, Belgium

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Virology Journal 2011, 8:134  doi:10.1186/1743-422X-8-134

Published: 23 March 2011

Abstract

Background

Although horizontal gene transfer plays a pivotal role in bacteriophage evolution, many lytic phage genomes are clearly shaped by vertical evolution. We investigated the influence of minor genomic deletions and insertions on various phage-related phenotypic and serological properties.

Findings

We collected ten different isolates of Pseudomonas aeruginosa bacteriophage ϕKMV. All sequenced genomes (42-43 kb, long direct terminal repeats) are nearly identical, which intuitively implied strongly similar infections cycles. However, their latent periods vary between 21 and 28 minutes and they are able to lyse between 5 and 58% of a collection of 107 clinical P. aeruginosa strains. We also noted that phages with identical tail structures displayed profound differences in host spectra. Moreover, point mutations in tail and spike proteins were sufficient to evade neutralization by two phage-specific antisera, isolated from rabbits.

Conclusion

Although all analyzed phages are 83-97% identical at the genome level, they display a surprisingly large variation in various phenotypic properties. The small overlap in host spectrum and their ability to readily escape immune defences against a nearly identical phage are promising elements for the application of these phages in phage therapy.