An emerging model for investigating virus-host interactions in hyperthermophilic Archaea is the Fusellovirus-Sulfolobus system. The host, Sulfolobus, is a hyperthermophilic acidophile endemic to sulfuric hot springs worldwide. The Fuselloviruses, also known as Sulfolobus Spindle-shaped Viruses (SSVs), are “lemon” or “spindle”-shaped double-stranded DNA viruses, which are also found worldwide. Although a few studies have addressed the host-range for the type virus, Sulfolobus Spindle-shaped Virus 1 (SSV1), using common Sulfolobus strains, a comprehensive host-range study for SSV-Sulfolobus systems has not been performed. Herein, we examine six bona fide SSV strains (SSV1, SSV2, SSV3, SSVL1, SSVK1, SSVRH) and their respective infection characteristics on multiple hosts from the family Sulfolobaceae. A spot-on-lawn or “halo” assay was employed to determine SSV infectivity (and host susceptibility) in parallel challenges of multiple SSVs on a lawn of a single Sulfolobus strain. Different SSVs have different host-ranges with SSV1 exhibiting the narrowest host-range and SSVRH exhibiting the broadest host range. In contrast to previous reports, SSVs can infect hosts beyond the genus Sulfolobus. Furthermore, geography does not appear to be a reliable predictor of Sulfolobus susceptibility to infection by any given SSV. The ability for SSVs to infect susceptible Sulfolobus host does not appear to change between 65°C and 88°C (physiological range); however, very low pH appears to influence infection. Lastly, for the virus-host pairs tested the Fusellovirus-Sulfolobus system appears to exhibit host-advantage. This work provides a foundation for understanding Fusellovirus biology and virus-host coevolution in extreme ecosystems.
Keywords: Archaea, Crenarchaea, Fusellovirus, halo assay, host-range, hyperthermophilic, Sulfolobus, Sulfolobus spindle-shaped virus
Citation: Ceballos RM, Marceau CD, Marceau JO, Morris S, Clore AJ and Stedman KM (2012) Differential virus host-ranges of the Fuselloviridae of hyperthermophilic Archaea: implications for evolution in extreme environments. Front. Microbio. 3:295. doi: 10.3389/fmicb.2012.00295
Received: 04 April 2012; Accepted: 24 July 2012;
Published online: 24 August 2012.
Edited by:Jennifer F. Biddle, University of Delaware, USA
Reviewed by:Richard Allen White III, University of British Columbia, Canada
Copyright © 2012 Ceballos, Marceau, Marceau, Morris, Clore and Stedman. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Ruben M. Ceballos, Native American Research Laboratory, Division of Science and Mathematics, The University of Minnesota, 600 East 4th Street, Morris, MN 56267, USA. e-mail: firstname.lastname@example.org