Efficient Dilution-to-Extinction isolation of novel virus-host model systems for fastidious heterotrophic bacteria
2
Citation
130
Reference
10
Related Paper
Citation Trend
Abstract:
Abstract Microbes and their associated viruses are key drivers of biogeochemical processes in marine and soil biomes. While viruses of phototrophic cyanobacteria are well-represented in model systems, challenges of isolating marine microbial heterotrophs and their viruses have hampered experimental approaches to quantify the importance of viruses in nutrient recycling. A resurgence in cultivation efforts has improved the availability of fastidious bacteria for hypothesis testing, but this has not been matched by similar efforts to cultivate their associated bacteriophages. Here, we describe a high-throughput method for isolating important virus-host systems for fastidious heterotrophic bacteria that couples advances in culturing of hosts with sequential enrichment and isolation of associated phages. Applied to six monthly samples from the Western English Channel, we first isolated one new member of the globally dominant bacterial SAR11 clade and three new members of the methylotrophic bacterial clade OM43. We used these as bait to isolate 117 new phages including the first known siphophage infecting SAR11, and the first isolated phage for OM43. Genomic analyses of 13 novel viruses revealed representatives of three new viral genera, and infection assays showed that the viruses infecting SAR11 have ecotype-specific host-ranges. Similar to the abundant human-associated phage ΦCrAss001, infection dynamics within the majority of isolates suggested either prevalent lysogeny or chronic infection, despite a lack of associated genes; or host phenotypic bistability with lysis putatively maintained within a susceptible subpopulation. Broader representation of important virus-host systems in culture collections and genomic databases will improve both our understanding of virus-host interactions, and accuracy of computational approaches to evaluate ecological patterns from metagenomic data.Keywords:
Fastidious organism
Lysogenic cycle
Marine bacteriophage
Ecotype
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 164:125-133 (1998) - doi:10.3354/meps164125 Prophage induction of indigenous marine lysogenic bacteria by environmental pollutants Pamela K. Cochran, Christina A. Kellogg, John H. Paul* Department of Marine Science, University of South Florida, 140 7th Ave. South, St. Petersburg, Florida 33701, USA *Addressee for correspondence. E-mail: jpaul@seas.marine.usf.edu Lysogenic bacteria may be abundant components of bacterial assemblages in marine waters. The tremendous number of viruses found in estuarine and other eutrophic environments may be the result in part of induction of prophages. Mitomycin C is the inducing agent of choice for prophage induction; however this is not naturally found in the marine environment. We determined the capability of environmentally important pollutants to effect prophage induction in natural populations of marine bacteria. We investigated Aroclor 1248, a PCB mixture, bunker C fuel oil #6, and a pesticide mixture as inducing agents for natural bacterial communities from the Gulf of Mexico. Mitomycin C was also employed as a positive control for induction. Induction was determined as a significant increase in viral direct counts compared to control and ranged from 149 to 1336% of the controls. Two-thirds of the environments sampled showed prophage induction by one of the methods utilized, with the PCB mixture and Aroclor 1248 giving the highest percent efficiency (75%) of induction. This study shows that many environmentally important pollutants may be inducing agents for natural lysogenic viral production in the marine environment. Marine bacteriophage · Lysogeny · Gulf of Mexico · Pollution Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 164. Publication date: April 09, 1998 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1998 Inter-Research.
Prophage
Lysogenic cycle
Marine bacteriophage
Cite
Citations (115)
Fastidious organism
Cite
Citations (1)
Lysogenic cycle
Prophage
Cite
Citations (5)
The affinities of the bacteriophage 434 repressor for its various binding sites depend on the type and/or concentration of monovalent cations. The ability of bacteriophage 434 repressor to govern the lysis-lysogeny decision depends on the DNA binding activities of the phage's cI repressor protein. We wished to determine whether changes in the intracellular ionic environment influence the lysis-lysogeny decision of the bacteriophage lambda(imm434). Our findings show that the ionic composition within bacterial cells varies with the cation concentration in the growth media. When lambda(imm434) lysogens were grown to mid-log or stationary phase and subsequently incubated in media with increasing monovalent salt concentrations, we observed a salt concentration-dependent increase in the frequency of bacteriophage spontaneous induction. We also found that the frequency of spontaneous induction varied with the type of monovalent cation in the medium. The salt-dependent increase in phage production was unaffected by a recA mutation. These findings indicate that the salt-dependent increase in phage production is not caused by activation of the SOS pathway. Instead, our evidence suggests that salt stress induces this lysogenic bacteriophage by interfering with 434 repressor-DNA interactions. We speculate that the salt-dependent increase in spontaneous induction is due to a direct effect on the repressor's affinity for DNA. Regardless of the precise mechanism, our findings demonstrate that salt stress can regulate the phage lysis-lysogeny switch.
Lysogenic cycle
Lysogen
Bacteriophage MS2
Cite
Citations (47)
Abstract Background Understanding the biological nature of bacteriophage is important in exploring the therapeutic and biotechnological potentials of bacteriophages. However, available information is limited to the infection processes on either model phages infecting Escherichia coli or lytic phages against pathogens. The interplay between lysogenic phage and its host was rarely studied. Results We investigated the interactions between Pseudomonas aeruginosa and a lysogenic bacteriophage PaP3 through RNA-seq and two-dimensional gel electrophoresis (2D-GE). Compared to the uninfected host, a total of 2,891 (51.3%) differentially expressed genes (DGEs) were identified, most of which were repressed by phages, including the changes in metabolic-related and virulence-associated genes. The RT-qPCR results showed consistent directional changes compared with the RNA-seq results. According to 2D-GE, phage structure proteins were detected after phage infection. The host proteins, such as flagella hook-associated proteins, disappeared gradually after phage infection and may be shut off by phage. Conclusions All these indicate that although lysogenic phages do not immediately lyse the host, they play a significant regulatory role in the expression of host genes. Our findings provide an expanded view of the lysogenic phage infection processes and may offer potential targets for therapeutic intervention against P. aeruginosa infections.
Lysogenic cycle
Lytic cycle
Phage therapy
Cite
Citations (0)
Strains of Bacillus subtilis lysogenic for temperate bacteriophage SPO2 inhibit the development of bacteriophage φ1. After infection by bacteriophage φ1, DNA and RNA synthesis in the lysogenic host terminates, culminating in cell death. Bacteriophage SPO2 also prevents the production of bacteriophage φ105. Mechanisms for these two types of bacteriophage interference are discussed.
Lysogenic cycle
Cite
Citations (29)
Serological tests and nitrogen determinations indicate that bacteriophage prepared by repeated washing of lysogenic cultures of B. coli contains little bacterial or other protein. Methods of preparation and concentration of such purified phage are described and some of its properties compared with those of homologous crude broth phage of similar titer and pH.
Lysogenic cycle
Cite
Citations (4)
Occurrence of lysogenic bacteria in marine microbial communities as determined by prophage induction
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 142:27-38 (1996) - doi:10.3354/meps142027 Occurrence of lysogenic bacteria in marine microbial communities as determined by prophage induction Jiang SC, Paul JH Viruses are abundant and dynamic members of the marine microbial community, and it is important to understand their role in the ecology of natural microbial populations. We have previously found lysogenic bacteria to be a significant proportion (43%) of the cultivable heterotrophic microbial population. As the majority of marine bacteria are not cultivable using standard plating methods, we measured the proportion of marine lysogenic bacteria in natural communities by prophage induction. Mitomycin C, UV radiation, sunlight, temperature and pressure were used to induce prophage in lysogenic bacteria from estuarine, coastal and oligotrophic offshore environments. To determine if hydrocarbon pollutants may cause the induction of marine lysogens, aromatic and aliphatic hydrocarbons (including Bunker C #6 fuel oil, phenanthrene, naphthalene, pyrene, and trichloroethylene) were also used as inducing agents. Induction was most often found in estuarine environments, where viral direct counts increased from 128.8 to 345% of the uninduced control, resulting in mortality of 10.5 to 67.3% (average 34%) of the bacterial population. Up to 38% of the bacterial population was lysogenized in estuarine environments, as calculated from an average burst size. Microbial populations from oligotrophic offshore environments were inducible at 3 of 11 stations sampled. Eight of the 11 samples (73%) treated with polyaromatic hydrocarbons resulted in prophage induction in natural populations. Time series analysis was also conducted in 2 samples induced by mitomycin C from the Atlantic Ocean near the coast of North Carolina, USA. For both samples, significant decreases in bacterial numbers were detected in treated samples after 8 h of incubation. A significant increase of viruses was detected at 8 h at one station and at 24 h at the other station after induction. This study indicates that natural lysogenic populations are sensitive to a variety of inducing agents, and induction occurs more frequently in coastal and estuarine environments than offshore environments. Virus · Bacteria · Lysogen · Marine microbial community · Induction Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 142. Publication date: October 24, 1996 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1996 Inter-Research.
Lysogenic cycle
Prophage
Marine bacteriophage
Cite
Citations (178)
Zimmerer, Robert P. (The Pennsylvania State University, University Park), Robert H. Hamilton, and Christine Pootjes . Isolation and morphology of temperate Agrobacterium tumefaciens bacteriophage. J. Bacteriol. 92: 746–750. 1966.—Lysogeny was detected in 14 strains of Agrobacterium tumefaciens among 130 bacterial strains tested with strain B-6 used as the host. Partial lysis was observed with 13 additional bacterial strains. Morphological studies of five strains showed that the phage had similar features. A typical phage (Lv-1) had a polyhedralshaped head, approximately 71 by 63 mμ, and a tail, approximately 211 mμ by 9.5 mμ. The phage nucleic acid was found to be deoxyribonucleic acid. The bacteriophage have been designated L (for lysogenic) followed by the bacterial strain designation in lower case letters.
Lysogenic cycle
Temperateness
Strain (injury)
Isolation
Cite
Citations (36)
vi Chapter One – Introduction 1 1.1 Viruses in the Marine Environment 1 1.1.1 Viral Distribution in the Marine Environment 2 1.1.2 Viral Effects on Nutrient Cycling 3 1.1.3 Gene Transfer and Other Viral-Mediated Processes 8 1.2 Virus Lifecycles 11 1.2.1 Lysis 11 1.2.2 Lysogeny 12 1.2.3 Pseudolysogeny 15 1.2.4 φHSIC 19 1.2.5 Lysogeny in the Marine Environment 20 1.3 Genomics 24 1.3.1 Marine Viral Genomics 24 1.3.2 The Genome of φHSIC 27 1.3.3 Gene Expression Analysis 32 Chapter Two – Macroarray Analysis of Gene Expression in a Marine Pseudotemperate Bacteriophage 35 2.
Lysogenic cycle
Marine bacteriophage
Horizontal Gene Transfer
Cite
Citations (0)