Pseudoalteromonas spp. phages, a significant group of marine bacteriophages in the North Sea

Wichels, Antje; Gerdts, Gunnar; Schütt, Christian

doi:10.3354/ame027233

Cited by 23 publications

(22 citation statements)

References 25 publications

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“…T from the Antarctic, thus qualifying, like many marine Siphoviridae, as a virus with a broad host range according to the criteria of Wichels et al (2002). Conclusions reached about host range, however, depend critically on experimental conditions and type of assay.…”

Section: One-step Growth Curvesmentioning

confidence: 99%

Characterization of a cold-active bacteriophage on two psychrophilic marine hosts

Wells¹,

Deming²

2006

Aquat. Microb. Ecol.

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A cold-active bacteriophage designated 9A was isolated against Colwellia psychrerythraea Strain 34H at near in situ temperature (-1°C) by enrichment of seawater from an Arctic nepheloid layer, using a newly developed isothermal overlay technique. Phage 9A is classified as a Siphoviridae with a genome size of 80 to 90 kb. In addition to 34H, 9A infects C. demingiae ACAM 459 T ; no other hosts (of 22 tested) were identified. In replete media, 9A formed plaques on 34H from -6 to 4°C and on C. demingiae from -6 to 8°C; the temperature range of plaque formation on 34H could be extended to 8°C by prior host starvation. An indirect plating method and microscopic evaluation also determined phage production at temperatures between -13 and -10°C. At -1°C, 34H had a broader salinity range of plaque formation than C. demingiae: 20 to 50 (but not 65) psu vs. 27 to 34 (but not 50) psu. As monitored by epifluorescence microscopy, phage production by 34H was observed at 1, 10, 100 and 200 atm (all at -1°C), but not at 400 or 600 atm. The 9A-34H system commonly had a low efficiency of plating (EOP; typically ~1%) which varied with culture age. Despite repeated attempts, no meaningful adsorption rate could be determined at -1 or 8°C. This result, the low EOP, and the effect of starvation on plaque formation suggest that fluctuating host phenotypes may play an important role in the dynamics of this system. One-step growth curves (using 34H as host) revealed a longer latent period (4 to 5 vs. 2.5 to 3 h) and greater burst size (55 vs. 5) at -1 than 8°C; at temperatures between -10 and -12°C, the estimated latent period was 5-10 d and the burst size 5. At both -1 and 8°C, rise times were comparable to latent periods. Although the cycle from infection to burst at -1°C required only 10 to 20% of the generation time of 34H at this temperature, the amount of viral DNA synthesized was comparable to the size of the host genome, suggesting very efficient and cold-active virus-encoded enzymes.KEY WORDS: Virus · Phage 9A · Colwellia psychrerythraea 34H · Colwellia demingiae · Arctic · Adsorption · One-step growth curve · Pressure · Salinity Resale or republication not permitted without written consent of the publisherAquat Microb Ecol 45: [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] 2006 'psychrophilic ' (e.g. Stamatin 1963, Olsen 1967, Ackermann & DuBow 1987 or 'psychrotrophic' (Greer 1982, 1983, Patel & Jackman 1986, the terms are ambiguous or misleading, since they imply growth characteristics of the host, not features necessarily specific to the virus (e.g. the temperature range of infection by a given virus may change with different hosts). For the sake of clarity, we define as 'cold-active' those viruses capable of infection and production at ≤ 4°C. This upper limit accords with the sparse literature about phage infection at low temperature and encompasses the temperatures of the perennially cold regions of the ocean. By this definition, several phage or phage-host systems (PHS) termed 'psychrophilic' or 'p...

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Section: One-step Growth Curvesmentioning

confidence: 99%

Characterization of a cold-active bacteriophage on two psychrophilic marine hosts

Wells¹,

Deming²

2006

Aquat. Microb. Ecol.

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“…The host, Pseudoalteromonas sp. H105, is susceptible to lysis or growth inhibition by other Helgoland and North Sea phages, including members of both the Myovridae and Siphoviridae families (Wichels et al, 1998(Wichels et al, , 2002.…”

Section: Introductionmentioning

confidence: 99%

“…Pseudoalteromonads are ubiquitous heterotrophic members of marine bacterial communities, which, as with most microbial life, are ecologically and evolutionarily influenced by phages (Moebus, 1992;Wichels et al, 1998Wichels et al, , 2002Männistö et al, 1999;Médigue et al, 2005;Thomas et al, 2008). All three sequenced Pseudoalteromonads contain integrated prophages, two of which are dominated by P2-like myovirus proteins (Prophinder) (Lima-Mendez et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Ecogenomics and genome landscapes of marine Pseudoalteromonas phage H105/1

et al. 2010

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Marine phages have an astounding global abundance and ecological impact. However, little knowledge is derived from phage genomes, as most of the open reading frames in their small genomes are unknown, novel proteins. To infer potential functional and ecological relevance of sequenced marine Pseudoalteromonas phage H105/1, two strategies were used. First, similarity searches were extended to include six viral and bacterial metagenomes paired with their respective environmental contextual data. This approach revealed 'ecogenomic' patterns of Pseudoalteromonas phage H105/1, such as its estuarine origin. Second, intrinsic genome signatures (phylogenetic, codon adaptation and tetranucleotide (tetra) frequencies) were evaluated on a resolved intragenomic level to shed light on the evolution of phage functional modules. On the basis of differential codon adaptation of Phage H105/1 proteins to the sequenced Pseudoalteromonas spp., regions of the phage genome with the most 'host'-adapted proteins also have the strongest bacterial tetra signature, whereas the least 'host'-adapted proteins have the strongest phage tetra signature. Such a pattern may reflect the evolutionary history of the respective phage proteins and functional modules. Finally, analysis of the structural proteome identified seven proteins that make up the mature virion, four of which were previously unknown. This integrated approach combines both novel and classical strategies and serves as a model to elucidate ecological inferences and evolutionary relationships from phage genomes that typically abound with unknown gene content.

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“…For instance, the single-host enrichment protocol may select for phages with a narrow host range (22,64), and infection and lysis by low-virulence phages, which typically have a broad host range (22), may not be detected in plaque assays (10). However, some marine phages are known to infect different strains of the same species (12,51,64) or even different species (10)(11)(12). Hence, the specificity of phage-host interactions in marine waters needs to be better characterized and understood.…”

mentioning

confidence: 99%

Large Variabilities in Host Strain Susceptibility and Phage Host Range Govern Interactions between Lytic Marine Phages and Their Flavobacterium Hosts

Holmfeldt¹,

Middelboe

Nybroe

et al. 2007

Appl Environ Microbiol

187

194

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Phages are a main mortality factor for marine bacterioplankton and are thought to regulate bacterial community composition through host-specific infection and lysis. In the present study we demonstrate for a marine phage-host assemblage that interactions are complex and that specificity and efficiency of infection and lysis are highly variable among phages infectious to strains of the same bacterial species. Twenty-three Bacteroidetes strains and 46 phages from Swedish and Danish coastal waters were analyzed. Based on genotypic and phenotypic analyses, 21 of the isolates could be considered strains of Cellulophaga baltica (Flavobacteriaceae). Nevertheless, all bacterial strains showed unique phage susceptibility patterns and differed by up to 6 orders of magnitude in sensitivity to the same titer of phage. The isolated phages showed pronounced variations in genome size (8 to >242 kb) and host range (infecting 1 to 20 bacterial strains). Our data indicate that marine bacterioplankton are susceptible to multiple co-occurring phages and that sensitivity towards phage infection is strain specific and exists as a continuum between highly sensitive and resistant, implying an extremely complex web of phage-host interactions. Hence, effects of phages on bacterioplankton community composition and dynamics may go undetected in studies where strain identity is not resolvable, i.e., in studies based on the phylogenetic resolution provided by 16S rRNA gene or internal transcribed spacer sequences.

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Pseudoalteromonas spp. phages, a significant group of marine bacteriophages in the North Sea

Cited by 23 publications

References 25 publications

Characterization of a cold-active bacteriophage on two psychrophilic marine hosts

Characterization of a cold-active bacteriophage on two psychrophilic marine hosts

Ecogenomics and genome landscapes of marine Pseudoalteromonas phage H105/1

Large Variabilities in Host Strain Susceptibility and Phage Host Range Govern Interactions between Lytic Marine Phages and Their Flavobacterium Hosts

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