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Riber L, Carstens AB, Dougherty PE, Roy C, Willenbücher K, Hille F, Franz CMAP, Hansen LH. Pheno- and Genotyping of Three Novel Bacteriophage Genera That Target a Wheat Phyllosphere Sphingomonas Genus. Microorganisms 2023; 11:1831. [PMID: 37513003 PMCID: PMC10385605 DOI: 10.3390/microorganisms11071831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 07/14/2023] [Accepted: 07/16/2023] [Indexed: 07/30/2023] Open
Abstract
Bacteriophages are viral agents that infect and replicate within bacterial cells. Despite the increasing importance of phage ecology, environmental phages-particularly those targeting phyllosphere-associated bacteria-remain underexplored, and current genomic databases lack high-quality phage genome sequences linked to specific environmentally important bacteria, such as the ubiquitous sphingomonads. Here, we isolated three novel phages from a Danish wastewater treatment facility. Notably, these phages are among the first discovered to target and regulate a Sphingomonas genus within the wheat phyllosphere microbiome. Two of the phages displayed a non-prolate Siphovirus morphotype and demonstrated a narrow host range when tested against additional Sphingomonas strains. Intergenomic studies revealed limited nucleotide sequence similarity within the isolated phage genomes and to publicly available metagenome data of their closest relatives. Particularly intriguing was the limited homology observed between the DNA polymerase encoding genes of the isolated phages and their closest relatives. Based on these findings, we propose three newly identified genera of viruses: Longusvirus carli, Vexovirus birtae, and Molestusvirus kimi, following the latest ICTV binomial nomenclature for virus species. These results contribute to our current understanding of phage genetic diversity in natural environments and hold promising implications for phage applications in phyllosphere microbiome manipulation strategies.
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Affiliation(s)
- Leise Riber
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg, Denmark
| | - Alexander Byth Carstens
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg, Denmark
| | - Peter Erdmann Dougherty
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg, Denmark
| | - Chayan Roy
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg, Denmark
| | - Katharina Willenbücher
- Department of Microbiology and Biotechnology, Max Rubner-Institut, Hermann-Weigmann-Strasse 1, 24103 Kiel, Germany
| | - Frank Hille
- Department of Microbiology and Biotechnology, Max Rubner-Institut, Hermann-Weigmann-Strasse 1, 24103 Kiel, Germany
| | - Charles M A P Franz
- Department of Microbiology and Biotechnology, Max Rubner-Institut, Hermann-Weigmann-Strasse 1, 24103 Kiel, Germany
| | - Lars Hestbjerg Hansen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg, Denmark
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2
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Preenanka R, Safeena MP. Morphological, biological and genomic characterization of lytic phages against Streptococcus agalactiae causing streptococcosis in tilapia. Microb Pathog 2023; 174:105919. [PMID: 36460145 DOI: 10.1016/j.micpath.2022.105919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 11/17/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022]
Abstract
Streptococcus agalactiae, a highly invasive pathogen causing streptococcosis, is a major disease imparting devastating effect in the aquaculture, worldwide. As bacteriophage therapy is getting more attention recently, as an alternative viable biocontrol agent to antibiotic and vaccine, this study aimed to isolate and purify obligately lytic bacteriophages and study its morphological, genetic and biological characteristics. Host range analysis of the four bacteriophages isolated in this study, such as Phage- 12 P, 15 F, 16 E and 20D exhibited 100% infectivity to S. agalactiae serotype Ia, a predominant serotype infecting fish. Morphotype of the phages was revealed by HR-TEM and found that the phage 20D belong to the family Myoviridae and the phages 12 P, 15 F, 16 E belonged to the family Siphoviridae with typical head and tail structure. Lytic potential of the phages were ascertained by multiplicity of infection and one step lytic curve and it is found that the phages exhibit high burst size at an MOI of 0.01. Random amplified polymorphic DNA revealed the genetic diversity of these four phages with distinct banding pattern. The phages were found to be lytic with the absence of genes coding for integrase, transposase and recombinase on PCR based screening. Phages exhibited stability and viability at various physic-chemical parameters such as temperature ranging from 4 to 45 °C, pH of 4-12 and salinity ranging from 0 to 6%. Thus the present study revealed that S. agalactiae specific phages such as Phage- 12 P, 15 F, 16 E and 20D are highly stable and potential to eliminate the S. agalactiae serotype Ia infecting fish. After the complete characterization of the phages by whole genome sequencing and exploring the defense function against S. agalactiae infection in vivo, it may be applied as a therapeutic agent against S. agalactiae infection in aquaculture.
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Affiliation(s)
- R Preenanka
- Faculty of Ocean Science and Technology (FOST), Kerala University of Fisheries and Ocean Studies (KUFOS), Panangad, Kochi, 682 506, Kerala, India.
| | - Muhammed P Safeena
- Department of Aquatic Animal Health Management (AAHM), Faculty of Fisheries Science, Kerala University of Fisheries and Ocean Studies (KUFOS), Panangad, Kochi, 682 506, Kerala, India.
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3
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Sala-Comorera L, Nolan TM, Reynolds LJ, Venkatesh A, Cheung L, Martin NA, Stephens JH, Gitto A, O'Hare GMP, O'Sullivan JJ, Meijer WG. Bacterial and Bacteriophage Antibiotic Resistance in Marine Bathing Waters in Relation to Rivers and Urban Streams. Front Microbiol 2021; 12:718234. [PMID: 34381437 PMCID: PMC8350879 DOI: 10.3389/fmicb.2021.718234] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 06/28/2021] [Indexed: 12/24/2022] Open
Abstract
Fecal pollution of surface water may introduce bacteria and bacteriophages harboring antibiotic resistance genes (ARGs) into the aquatic environment. Watercourses discharging into the marine environment, especially close to designated bathing waters, may expose recreational users to fecal pollution and therefore may increase the likelihood that they will be exposed to ARGs. This study compares the bacterial and bacteriophage ARG profiles of two rivers (River Tolka and Liffey) and two small urban streams (Elm Park and Trimleston Streams) that discharge close to two marine bathing waters in Dublin Bay. Despite the potential differences in pollution pressures experienced by these waterways, microbial source tracking analysis showed that the main source of pollution in both rivers and streams in the urban environment is human contamination. All ARGs included in this study, blaTEM, blaSHV, qnrS, and sul1, were present in all four waterways in both the bacterial and bacteriophage fractions, displaying a similar ARG profile. We show that nearshore marine bathing waters are strongly influenced by urban rivers and streams discharging into these, since they shared a similar ARG profile. In comparison to rivers and streams, the levels of bacterial ARGs were significantly reduced in the marine environment. In contrast, the bacteriophage ARG levels in freshwater and the marine were not significantly different. Nearshore marine bathing waters could therefore be a potential reservoir of bacteriophages carrying ARGs. In addition to being considered potential additional fecal indicators organism, bacteriophages may also be viewed as indicators of the spread of antimicrobial resistance.
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Affiliation(s)
- Laura Sala-Comorera
- UCD School of Biomolecular and Biomedical Science, UCD Earth Institute, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Tristan M Nolan
- UCD School of Biomolecular and Biomedical Science, UCD Earth Institute, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Liam J Reynolds
- UCD School of Biomolecular and Biomedical Science, UCD Earth Institute, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Anjan Venkatesh
- UCD School of Biomolecular and Biomedical Science, UCD Earth Institute, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Lily Cheung
- UCD School of Biomolecular and Biomedical Science, UCD Earth Institute, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Niamh A Martin
- UCD School of Biomolecular and Biomedical Science, UCD Earth Institute, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Jayne H Stephens
- UCD School of Biomolecular and Biomedical Science, UCD Earth Institute, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Aurora Gitto
- UCD School of Biomolecular and Biomedical Science, UCD Earth Institute, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Gregory M P O'Hare
- UCD School of Computer Science, UCD Earth Institute, University College Dublin, Dublin, Ireland
| | - John J O'Sullivan
- UCD School of Civil Engineering, UCD Dooge Centre for Water Resources Research, UCD Earth Institute, University College Dublin, Dublin, Ireland
| | - Wim G Meijer
- UCD School of Biomolecular and Biomedical Science, UCD Earth Institute, UCD Conway Institute, University College Dublin, Dublin, Ireland
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4
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Ji J, Liu Q, Wang R, Luo T, Guo X, Xu M, Yin Q, Wang X, Zhou M, Li M, He P. Identification of a novel phage targeting methicillin-resistant Staphylococcus aureus In vitro and In vivo. Microb Pathog 2020; 149:104317. [PMID: 32512153 DOI: 10.1016/j.micpath.2020.104317] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 05/31/2020] [Accepted: 05/31/2020] [Indexed: 01/21/2023]
Abstract
INTRODUCTION Staphylococcus aureus is a common human pathogen that causes various diseases including infections on the skin, in the bloodstream and the lower respiratory tracts. The emergence of methicillin-resistant S. aureus (MRSA) made the treatment of the bacterial infection more difficult, calling for development of new therapeutics. Compared with conventional antibiotic therapy, phage therapy offers a promising alternative to combat infections caused by MRSA. RESULTS Here we showed that phage VB_SauS_SH-St 15644 isolated from sewage inhibited MRSA isolates in vitro and in the murine skin infection model. Phage VB_SauS_SH-St 15644 belongs to Siphoviridae. The genome of the phage is a linear, 45,111 bp double-stranded DNA with GC content of 33.35%. Among the 37 clinical MRSA isolates tested, 12 (32%) were lysed by the phage in vitro. The phage was relatively stable at temperatures up to 40 °C or between pH 6 and 9. However, the phage was sensitive to UV light. 80% of the phage was approximately adsorbed to the host MRSA isolate in 4 min. The one-step growth curve showed that the latent period was about 12 min followed by the growth period (about 9 min). The burst size was estimated at 13 PFU per infected cell. Furthermore, in a murine skin infection model, the phage significantly inhibited MRSA infection. CONCLUSIONS Our study suggested that phage VB_SauS_SH-St 15644 has a potential to inhibit MRSA skin infection.
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Affiliation(s)
- Jiawei Ji
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China; Department of Medical Microbiology and Immunology, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Qian Liu
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Rui Wang
- Department of Medical Microbiology and Immunology, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Tingting Luo
- Department of Pharmaceutical Engineering, Zhejiang Pharmaceutical College, Ningbo, China
| | - Xiaokui Guo
- Department of Medical Microbiology and Immunology, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Mengsha Xu
- Department of Medical Microbiology and Immunology, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Qian Yin
- Department of Medical Microbiology and Immunology, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Xuetong Wang
- Department of Medical Microbiology and Immunology, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Min Zhou
- Institute of Respiratory Diseases, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Min Li
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
| | - Ping He
- Department of Medical Microbiology and Immunology, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
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5
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Drucker VV, Belykh OI, Gorshkova AS, Bondar AA, Sykilinda NN. Autochthonous Bacteriophages in the Microbial Loop Structure of Different Biotopes of Lake Baikal. CONTEMP PROBL ECOL+ 2019. [DOI: 10.1134/s1995425519020045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Marie V, Lin J. Viruses in the environment - presence and diversity of bacteriophage and enteric virus populations in the Umhlangane River, Durban, South Africa. JOURNAL OF WATER AND HEALTH 2017; 15:966-981. [PMID: 29215360 DOI: 10.2166/wh.2017.066] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Due to the continued persistence of waterborne viral-associated infections, the presence of enteric viruses is a concern. Notwithstanding the health implications, viral diversity and abundance is an indicator of water quality declination in the environment. The aim of this study was to evaluate the presence of viruses (bacteriophage and enteric viruses) in a highly polluted, anthropogenic-influenced river system over a 6-month period at five sampling points. Cytopathic-based tissue culture assays revealed that the isolated viruses were infectious when tested on Hep-G2, HEK293 and Vero cells. While transmission electron microscopy (TEM) revealed that the majority of the viruses were bacteriophages, a number of presumptive enteric virus families were visualized, some of which include Picornaviridae, Adenoviridae, Polyomaviridae and Reoviridae. Finally, primer specific nested polymerase chain reaction (nested-PCR)/reverse transcription-polymerase chain reaction (RT-PCR) coupled with BLAST analysis identified human adenovirus, polyomavirus and hepatitis A and C virus genomes in river water samples. Taken together, the complexity of both bacteriophage and enteric virus populations in the river has potential health implications. Finally, a systematic integrated risk assessment and management plan to identify and minimize sources of faecal contamination is the most effective way of ensuring water safety and should be established in all future guidelines.
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Affiliation(s)
- Veronna Marie
- Discipline of Microbiology, School of Life Sciences, University of KwaZulu-Natal (Westville), Private Bag X54001, Durban, South Africa E-mail:
| | - Johnson Lin
- Discipline of Microbiology, School of Life Sciences, University of KwaZulu-Natal (Westville), Private Bag X54001, Durban, South Africa E-mail:
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7
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Flores V, Sepúlveda-Robles O, Cazares A, Kameyama L, Guarneros G. Comparative genomic analysis of Pseudomonas aeruginosa phage PaMx25 reveals a novel siphovirus group related to phages infecting hosts of different taxonomic classes. Arch Virol 2017; 162:2345-2355. [PMID: 28462462 DOI: 10.1007/s00705-017-3366-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 03/12/2017] [Indexed: 12/20/2022]
Abstract
Bacteriophages (phages) are estimated to be the most abundant and diverse entities in the biosphere harboring vast amounts of novel genetic information. Despite the genetic diversity observed, many phages share common features, such as virion morphology, genome size and organization, and can readily be associated with clearly defined phage groups. However, other phages display unique genomes or, alternatively, mosaic genomes composed of regions that share homology with those of phages of diverse origins; thus, their relationships cannot be easily assessed. In this work, we present a functional and comparative genomic analysis of Pseudomonas aeruginosa phage PaMx25, a virulent member of the Siphoviridae family. The genomes of PaMx25 and a highly homologous phage NP1, bore sequence homology and synteny with the genomes of phages that infect hosts different than Pseudomonas. In order to understand the relationship of the PaMx25 genome with that of other phages, we employed several computational approaches. We found that PaMx25 and NP1 effectively bridged several phage groups. It is expected that as more phage genomes become available, more gaps will be filled, blurring the boundaries that currently separate phage groups.
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Affiliation(s)
- Víctor Flores
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, Mexico
| | - Omar Sepúlveda-Robles
- Catedrático CONACyT - Coordinación de Investigación en Salud, Instituto Mexicano del Seguro Social (IMSS), Centro Médico Nacional Siglo XXI, Mexico City, Mexico
| | - Adrián Cazares
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, Mexico
| | - Luis Kameyama
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, Mexico
| | - Gabriel Guarneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, Mexico.
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8
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Colombet J, Robin A, Sime-Ngando T. Genotypic, size and morphological diversity of virioplankton in a deep oligomesotrophic freshwater lake (Lac Pavin, France). J Environ Sci (China) 2017; 53:48-59. [PMID: 28372760 DOI: 10.1016/j.jes.2016.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 05/02/2016] [Accepted: 05/05/2016] [Indexed: 06/07/2023]
Abstract
We examined changes in morphological and genomic diversities of viruses by means of transmission electronic microscopy and pulsed field gel electrophoresis (PFGE) over a nine-month period (April-December 2005) at four different depths in the oligomesotrophic Lac Pavin. We found that the majority of viruses in this lake belonged to the family of Siphoviridae or were untailed, with capsid sizes ranging from 30 to 60nm, and exhibited genome sizes ranging from 15 to 45kb. On average, 12 different genotypes dominated each of the PFGE fingerprints. The highest genomic viral richness was recorded in summer (mean=14 bands per PFGE fingerprint) and in the epilimnion (mean=13 bands per PFGE fingerprint). Among the physico-chemical and biological variables considered, the availability of the hosts appeared to be the main factor regulating the variations in the viral diversity.
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Affiliation(s)
- Jonathan Colombet
- Laboratory Microorganisms: Genome and Environment, Clermont University Blaise Pascal, UMR CNRS 6023, 24 avenue des Landais, BP 80026, F-63171 Aubière, France.
| | - Agnès Robin
- CIRAD, UMR Eco&Sols, 2 place Viala, 34060 Montpellier Cedex 1, France
| | - Télesphore Sime-Ngando
- Laboratory Microorganisms: Genome and Environment, Clermont University Blaise Pascal, UMR CNRS 6023, 24 avenue des Landais, BP 80026, F-63171 Aubière, France
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9
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Morphological diversity of cultured cold-active lytic bacteriophages isolated from the Napahai plateau wetland in China. Virol Sin 2016; 30:457-9. [PMID: 26685847 DOI: 10.1007/s12250-015-3674-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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10
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Yost DG, Tsourkas P, Amy PS. Experimental bacteriophage treatment of honeybees ( Apis mellifera) infected with Paenibacillus larvae, the causative agent of American Foulbrood Disease. BACTERIOPHAGE 2016; 6:e1122698. [PMID: 27144085 PMCID: PMC4836486 DOI: 10.1080/21597081.2015.1122698] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 10/15/2015] [Accepted: 11/13/2015] [Indexed: 12/20/2022]
Abstract
American Foulbrood Disease (AFB) is an infection of honeybees caused by the bacterium Paenibacillus larvae. One potential remedy involves using biocontrol, such as bacteriophages (phages) to lyse P. larvae. Therefore, bacteriophages specific for P. larvae were isolated to determine their efficacy in lysing P. larvae cells. Samples from soil, beehive materials, cosmetics, and lysogenized P. larvae strains were screened; of 157 total samples, 28 were positive for at least one P. larvae bacteriophage, with a total of 30. Newly isolated bacteriophages were tested for the ability to lyse each of 11 P. larvae strains. Electron microscopy demonstrated that the phage isolates were from the family Siphoviridae. Seven phages with the broadest host ranges were combined into a cocktail for use in experimental treatments of infected bee larvae; both prophylactic and post-infection treatments were conducted. Results indicated that although both pre- and post-treatments were effective, prophylactic administration of the phages increased the survival of larvae more than post-treatment experiments. These preliminary experiments demonstrate the likelihood that phage therapy could be an effective method to control AFB.
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Affiliation(s)
- Diane G Yost
- School of Life Sciences, University of Nevada , Las Vegas, Nevada, USA
| | | | - Penny S Amy
- School of Life Sciences, University of Nevada , Las Vegas, Nevada, USA
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11
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Henry KA, Arbabi-Ghahroudi M, Scott JK. Beyond phage display: non-traditional applications of the filamentous bacteriophage as a vaccine carrier, therapeutic biologic, and bioconjugation scaffold. Front Microbiol 2015; 6:755. [PMID: 26300850 PMCID: PMC4523942 DOI: 10.3389/fmicb.2015.00755] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 07/10/2015] [Indexed: 12/23/2022] Open
Abstract
For the past 25 years, phage display technology has been an invaluable tool for studies of protein-protein interactions. However, the inherent biological, biochemical, and biophysical properties of filamentous bacteriophage, as well as the ease of its genetic manipulation, also make it an attractive platform outside the traditional phage display canon. This review will focus on the unique properties of the filamentous bacteriophage and highlight its diverse applications in current research. Particular emphases are placed on: (i) the advantages of the phage as a vaccine carrier, including its high immunogenicity, relative antigenic simplicity and ability to activate a range of immune responses, (ii) the phage's potential as a prophylactic and therapeutic agent for infectious and chronic diseases, (iii) the regularity of the virion major coat protein lattice, which enables a variety of bioconjugation and surface chemistry applications, particularly in nanomaterials, and (iv) the phage's large population sizes and fast generation times, which make it an excellent model system for directed protein evolution. Despite their ubiquity in the biosphere, metagenomics work is just beginning to explore the ecology of filamentous and non-filamentous phage, and their role in the evolution of bacterial populations. Thus, the filamentous phage represents a robust, inexpensive, and versatile microorganism whose bioengineering applications continue to expand in new directions, although its limitations in some spheres impose obstacles to its widespread adoption and use.
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Affiliation(s)
- Kevin A. Henry
- Human Health Therapeutics Portfolio, National Research Council Canada, OttawaON, Canada
| | - Mehdi Arbabi-Ghahroudi
- Human Health Therapeutics Portfolio, National Research Council Canada, OttawaON, Canada
- School of Environmental Sciences, University of Guelph, GuelphON, Canada
- Department of Biology, Carleton University, OttawaON, Canada
| | - Jamie K. Scott
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BCCanada
- Faculty of Health Sciences, Simon Fraser University, BurnabyBC, Canada
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12
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Azizian R, Nasser A, Askari H, Taheri Kalani M, Sadeghifard N, Pakzad I, Amini R, Mozaffari Nejad AS, Azizi Jalilian F. Sewage as a rich source of phage study against Pseudomonas aeruginosa PAO. Biologicals 2015; 43:238-41. [PMID: 26049814 DOI: 10.1016/j.biologicals.2015.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Revised: 04/29/2015] [Accepted: 05/04/2015] [Indexed: 11/24/2022] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous organism which has emerged as a major public health threat in hospital environments. Overuse of antibiotics has significantly exacerbated the emergence of multi-drug resistant bacteria such as P. aeruginosa. Phages are currently being utilized successfully for aquaculture, agriculture and veterinary applications. The aim of this study was to isolate and characterize of lytic P. aeruginosa phage from sewage of Ilam, Iran. Phage was isolated from sewage that was added to the enrichment along with the host and subsequently filtered. Plaque assay was done by using an overlay method (also called the double agar layer method). Purified plaques were then amplified for characterization. Finally, RAPD-PCR method was conducted for genotyping and Transition electron micrograph (TEM) recruited to determine the morphology and phage family. The phage had high concentration and tremendous effects against a variety of clinical and general laboratory strains (ATCC15693) of P. aeruginosa. Among a set of primers in RAPD panel, only P2 and RAPD5 primers, were useful in differentiating the phages. TEM images revealed that the isolated phages were members of the Siphoviridae family. The phage effectiveness and specificity towards target bacteria and potential to control biofilm formations will be investigate in our further studies.
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Affiliation(s)
- Reza Azizian
- Department of Medical Microbiology, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran; Student Research Committee, Ilam University of Medical Sciences, Ilam, Iran
| | - Ahmad Nasser
- Department of Medical Microbiology, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran; Student Research Committee, Ilam University of Medical Sciences, Ilam, Iran
| | - Hasan Askari
- Department of Medical Microbiology, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran; Student Research Committee, Ilam University of Medical Sciences, Ilam, Iran
| | - Morovat Taheri Kalani
- Department of Medical Microbiology, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran; Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
| | - Nourkhoda Sadeghifard
- Department of Medical Microbiology, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran; Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
| | - Iraj Pakzad
- Department of Medical Microbiology, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran; Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
| | - Razieh Amini
- Research Center for Molecular Medicine, Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Amir Sasan Mozaffari Nejad
- Research Center for Molecular Medicine, Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Farid Azizi Jalilian
- Research Center for Molecular Medicine, Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
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13
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Ganesh A, Lin J, Singh M. Detecting Virus-Like Particles from the Umgeni River, South Africa. CLEAN : SOIL, AIR, WATER 2014; 42:393-407. [PMID: 32313584 PMCID: PMC7159345 DOI: 10.1002/clen.201200564] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 03/17/2013] [Accepted: 04/04/2013] [Indexed: 05/03/2023]
Abstract
It is important to consider viruses in water quality because of their incidence as causal agents for diarrhoeal disease, and due to their characteristics, which allow them to survive in changing environmental conditions indefinitely. This study assessed the viral quality of the Umgeni River in South Africa seasonally. A two-step tangential flow filtration process was setup to remove the bacteria and to concentrate the virus populations from large volume water samples. The concentrated water samples contained up to 659 and 550 pfu/mL of somatic and F-RNA coliphages, respectively. Several virus families including Adenoviridae, Herpesviridae, Orthomyxoviridae, Picornaviridae, Poxviridae and Reoviridae were found in the river based on the morphologies examined under transmission electron microscopy. All concentrated water samples produced substantial cytopathic effects on the Vero, HEK 293, Hela and A549 cell lines. These results indicate the potential of viruses in the water samples especially from the lower catchment areas of the Umgeni River to infect human hosts throughout the year. The present study highlights the importance of routine environmental surveillance of human enteric viruses in water sources. This can contribute to a better understanding of the actual burden of disease on those who might be using the water directly without treatment.
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Affiliation(s)
- Atheesha Ganesh
- Discipline of Microbiology, School of Life Sciences University of KwaZulu-Natal (Westville) Durban South Africa
| | - Johnson Lin
- Discipline of Microbiology, School of Life Sciences University of KwaZulu-Natal (Westville) Durban South Africa
| | - Moganavelli Singh
- Discipline of Biochemistry, School of Life Sciences University of KwaZulu-Natal (Westville) Durban South Africa
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14
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Abstract
Since the advent of the electron microscope approximately 70 years ago, bacterial viruses and electron microscopy are inextricably linked. Electron microscopy proved that bacteriophages are particulate and viral in nature, are complex in size and shape, and have intracellular development cycles and assembly pathways. The principal contribution of electron microscopy to bacteriophage research is the technique of negative staining. Over 5500 bacterial viruses have so far been characterized by electron microscopy, making bacteriophages, at least on paper, the largest viral group in existence. Other notable contributions are cryoelectron microcopy and three-dimensional image reconstruction, particle counting, and immunoelectron microscopy. Scanning electron microscopy has had relatively little impact. Transmission electron microscopy has provided the basis for the recognition and establishment of bacteriophage families and is one of the essential criteria to classify novel viruses into families. It allows for instant diagnosis and is thus the fastest diagnostic technique in virology. The most recent major contribution of electron microscopy is the demonstration that the capsid of tailed phages is monophyletic in origin and that structural links exist between some bacteriophages and viruses of vertebrates and archaea. DNA sequencing cannot replace electron microscopy and vice versa.
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Affiliation(s)
- Hans-W Ackermann
- Department of Microbiology, Epidemiology and Infectiology, Faculty of Medicine, Laval University, Quebec, Canada
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15
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Global morphological analysis of marine viruses shows minimal regional variation and dominance of non-tailed viruses. ISME JOURNAL 2013; 7:1738-51. [PMID: 23635867 DOI: 10.1038/ismej.2013.67] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 03/16/2013] [Accepted: 03/19/2013] [Indexed: 11/08/2022]
Abstract
Viruses influence oceanic ecosystems by causing mortality of microorganisms, altering nutrient and organic matter flux via lysis and auxiliary metabolic gene expression and changing the trajectory of microbial evolution through horizontal gene transfer. Limited host range and differing genetic potential of individual virus types mean that investigations into the types of viruses that exist in the ocean and their spatial distribution throughout the world's oceans are critical to understanding the global impacts of marine viruses. Here we evaluate viral morphological characteristics (morphotype, capsid diameter and tail length) using a quantitative transmission electron microscopy (qTEM) method across six of the world's oceans and seas sampled through the Tara Oceans Expedition. Extensive experimental validation of the qTEM method shows that neither sample preservation nor preparation significantly alters natural viral morphological characteristics. The global sampling analysis demonstrated that morphological characteristics did not vary consistently with depth (surface versus deep chlorophyll maximum waters) or oceanic region. Instead, temperature, salinity and oxygen concentration, but not chlorophyll a concentration, were more explanatory in evaluating differences in viral assemblage morphological characteristics. Surprisingly, given that the majority of cultivated bacterial viruses are tailed, non-tailed viruses appear to numerically dominate the upper oceans as they comprised 51-92% of the viral particles observed. Together, these results document global marine viral morphological characteristics, show that their minimal variability is more explained by environmental conditions than geography and suggest that non-tailed viruses might represent the most ecologically important targets for future research.
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16
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Hargreaves KR, Anderson NJ, Clokie MRJ. Recovery of viable cyanophages from the sediments of a eutrophic lake at decadal timescales. FEMS Microbiol Ecol 2012; 83:450-6. [PMID: 22963199 DOI: 10.1111/1574-6941.12005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 08/22/2012] [Accepted: 09/03/2012] [Indexed: 12/01/2022] Open
Abstract
Cyanobacteria and their associated viruses (cyanophages) are abundant throughout the world in both marine and freshwater environments. The predator-prey relationship influences population dynamics within these ecosystems and facilitates the co-evolution of both organisms. Evidence of the close-linked interactions between cyanobacteria and viruses has been found extensively throughout marine biomes, but freshwater systems are less well studied. Eutrophic lake sediments potentially allow the preservation of cyanophages. If historic cyanophages could be isolated, they could provide insights into the evolution, biology and population dynamics over defined timescales. To determine whether viable phages are present in this environment, sectioned sediment cores (~ 50 cm in length) were taken from a eutrophic, stratifying lake (Rostherne Mere, Cheshire, UK). They were examined under the transmission electron microscope, and phages were isolated on two Microcystis strains PCC 7820 and BC 84/1. Viable phages were recovered from ~ 33- and ~ 50-year-old sediments. This is the first known study to investigate the viability of freshwater cyanophages recovered from dated lake sediments.
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Affiliation(s)
- Kate R Hargreaves
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
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17
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Jakubowska-Deredas M, Jurczak-Kurek A, Richert M, Łoś M, Narajczyk M, Wróbel B. Diversity of tailed phages in Baltic Sea sediment: large number of siphoviruses with extremely long tails. Res Microbiol 2012; 163:292-6. [PMID: 22366738 DOI: 10.1016/j.resmic.2012.02.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 01/02/2012] [Indexed: 11/15/2022]
Abstract
We present the first attempt at quantitative analysis of morphological diversity of tailed viruses obtained from marine sediments without ultracentrifugation or enrichment on specific host strains. Sandy mud samples were collected in the Gulf of Gdańsk in the spring, autumn and winter. VLPs were analyzed by transmission electron microscopy. The distribution of three groups of tailed phages was similar in all seasons (Siphoviridae: 52% on average; Myoviridae: 42%; Podoviridae: 6%). 19% of siphoviruses had prolate heads. Interestingly, 11% of siphoviral particles had tails longer than 300 nm, and 6% longer than 600 nm.
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Affiliation(s)
- Magdalena Jakubowska-Deredas
- Department of Genetics and Marine Biotechnology, Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, 81-712 Sopot, Poland.
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18
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Williamson KE, Helton RR, Wommack KE. Bias in bacteriophage morphological classification by transmission electron microscopy due to breakage or loss of tail structures. Microsc Res Tech 2011; 75:452-7. [PMID: 21919126 DOI: 10.1002/jemt.21077] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 07/30/2011] [Indexed: 11/06/2022]
Abstract
Virtually every study that has used transmission electron microscopy (TEM) to estimate viral diversity has acknowledged that loss of phage tails during sample preparation may have biased the results. However, the magnitude of this potential bias has yet to be constrained. To characterize biases in virus morphological diversity due to tail loss, six phage strains representing the order Caudovirales were inoculated into sterile sediments and soils. Phage particles were then extracted using standard methods. Morphologies of extracted phage particles were compared to those of unmanipulated control samples to determine the extent of tail breakage incurred by extraction procedures. Podoviruses exhibited the smallest frequency of tail loss during extraction (1.2-14%), myoviruses were moderately susceptible to tail breakage (15-40%), and siphoviruses were highly susceptible (32-76%). Thus, TEM assessments of viral diversity in soils or sediments by distribution of tail morphologies may be biased toward podoviruses and virions lacking tails, while simultaneously underestimating the abundance of siphoviruses. However, since the majority of viral capsids observed under TEM were intact, estimates of viral diversity based on the distribution of capsid diameters may provide a more reliable basis for morphological comparisons within and across ecosystems.
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Affiliation(s)
- Kurt E Williamson
- Department of Biology, College of William and Mary, Williamsburg, Virginia 23186, USA.
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19
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Diversity of somatic coliphages in coastal regions with different levels of anthropogenic activity in São Paulo State, Brazil. Appl Environ Microbiol 2011; 77:4208-16. [PMID: 21531842 DOI: 10.1128/aem.02780-10] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacteriophages are the most abundant and genetically diverse viruses on Earth, with complex ecology in both quantitative and qualitative terms. Somatic coliphages (SC) have been reported to be good indicators of fecal pollution in seawater. This study focused on determining the concentration of SC and their diversity by electron microscopy of seawater, plankton, and bivalve samples collected at three coastal regions in São Paulo, Brazil. The SC counts varied from <1 to 3.4 × 10(3) PFU/100 ml in seawater (73 samples tested), from <1 to 4.7 × 10(2) PFU/g in plankton (46 samples tested), and from <1 to 2.2 × 10(1) PFU/g in bivalves (11 samples tested). In seawater samples, a relationship between the thermotolerant coliforms and Escherichia coli and SC was observed at the three regions (P = 0.0001) according to the anthropogenic activities present at each region. However, SC were found in plankton samples from three regions: Baixada Santista (17/20), Canal de São Sebastião (6/14), and Ubatuba (3/12). In seawater samples collected from Baixada Santista, four morphotypes were observed: A1 (4.5%), B1 (50%), C1 (36.4%), and D1 (9.1%). One coliphage, Siphoviridae type T1, had the longest tail: between 939 and 995 nm. In plankton samples, Siphoviridae (65.8%), Podoviridae (15.8%), Microviridae (15.8%), and Myoviridae (2.6%) were found. In bivalves, only the morphotype B1 was observed. These SC were associated with enteric hosts: enterobacteria, E. coli, Proteus, Salmonella, and Yersinia. Baixada Santista is an area containing a high level of fecal pollution compared to those in the Canal de São Sebastião and Ubatuba. This is the first report of coliphage diversity in seawater, plankton, and bivalve samples collected from São Paulo coastal regions. A better characterization of SC diversity in coastal environments will help with the management and evaluation of the microbiological risks for recreation, seafood cultivation, and consumption.
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20
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Brum JR, Steward GF. Morphological characterization of viruses in the stratified water column of alkaline, hypersaline Mono Lake. MICROBIAL ECOLOGY 2010; 60:636-43. [PMID: 20521038 DOI: 10.1007/s00248-010-9688-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Accepted: 05/06/2010] [Indexed: 05/25/2023]
Abstract
Concentrations of viruses and prokaryotes in the alkaline, moderately hypersaline, seasonally stratified Mono Lake are among the highest reported for a natural aquatic environment. We used electron microscopy to test whether viral morphological characteristics differed among the epilimnion, metalimnion, and the anoxic hypolimnion of the lake and to determine how the properties of viruses in Mono Lake compare to other aquatic environments. Viral capsid size distributions were more similar in the metalimnion and hypolimnion of Mono Lake, while viral tail lengths were more similar in the epilimnion and metalimnion. The percentage of tailed viruses decreased with depth and the relative percentages of tailed phage families changed with depth. The presence of large (>125 nm capsid), untailed viruses in the metalimnion and hypolimnion suggests that eukaryotic viruses are produced in these suboxic and anoxic, hypersaline environments. Capsid diameters of viruses were larger on average in Mono Lake compared to other aquatic environments, and no lemon-shaped or filamentous viruses were found, in contrast to other high-salinity or high-altitude lakes and seas. Our data suggest that the physically and chemically distinct layers of Mono Lake harbor different viral assemblages, and that these assemblages are distinct from other aquatic environments that have been studied. Furthermore, we found that filtration of a sample through a 0.22-µm pore-size filter significantly altered the distribution of viral capsid diameters and tail lengths, resulting in a relative depletion of viruses having larger capsids and longer tails. This observation highlights the potential for bias in molecular surveys of viral diversity, which typically rely on filtration through 0.2- or 0.22-µm pore-size membrane filters to remove bacteria during sample preparation.
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Affiliation(s)
- Jennifer R Brum
- Department of Oceanography, University of Hawai'i at Manoa, 1000 Pope Rd., MSB 205, Honolulu, HI 96822, USA.
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21
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Indirect interactions in the microbial world: specificities and similarities to plant–insect systems. POPUL ECOL 2010. [DOI: 10.1007/s10144-010-0235-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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22
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Hennes KP, Simon M. Significance of bacteriophages for controlling bacterioplankton growth in a mesotrophic lake. Appl Environ Microbiol 2010; 61:333-40. [PMID: 16534914 PMCID: PMC1388335 DOI: 10.1128/aem.61.1.333-340.1995] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterium-specific viruses have attracted much interest in aquatic microbial ecology because they have been shown to be about 10 times more abundant than planktonic bacteria. So far most of the studies of interactions of planktonic bacteria and viruses have been done in marine environments, and very little is known about these interactions in lakes. Therefore, we studied phage proliferation in Lake Constance, a large mesotrophic lake in Germany. We enumerated bacteria and quantified the fraction of bacteria with mature intracellular phage particles and the number of free viruses by transmission electron microscopy. Between the end of March and early August 1992, peaks of bacterial abundance were followed in 1 to 2 weeks by peaks in the fraction of bacteria containing visible phage particles (0 to 1.7%) and in the number of free viruses (1 x 10(sup7) to 4 x 10(sup7) ml(sup-1)). We estimated that 1 to 17% +/- 12% of all bacteria were phage infected, implying that phage-induced mortality was <34% +/- 24% of total mortality. A direct comparison between phage-induced mortality, the net decrease of bacterial numbers, and bacterial growth rates indicated that phage-induced mortality accounted for <11% of total bacterial mortality during the phytoplankton spring bloom and 18 to 21% following the bloom. Estimated burst sizes ranged from 21 to 121 phages. Phage production rates of 0.5 x 10(sup6) to 2.5 x 10(sup6) ml(sup-1) day(sup-1) accounted for 70 to 380% of the observed net increase rates of free phages, implying high rates of simultaneous phage decay. The cyclic dynamics between bacteria and phages and the varying size structure of the intracellular mature phage particles suggested that phage infection was important in structuring the bacterial host assemblage during the study period.
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23
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Abstract
In this review, available data on the structure (diversity, abundance, biomass) and functional imprints (bacteriolysis, lysogeny, gene transfers, regulation of prokaryotic diversity) of natural viruses in the context of food webs in aquatic microbial ecology, and the related biogeochemical cycles, are summarized. Viruses are the most abundant, and probably the most diverse, biological entities in aquatic ecosystems and in the biosphere (i.e., viriosphere). Aquatic viruses typically exceed 107 particles/mL in mesotrophic conditions, the majority being represented by phages without tails and by tailed-phages such as members of the family Siphoviridae. Both types of phages have a small capsid and a small genome size, which is considered an evolutionary adaptation to planktonic life. Their contribution to microbial mortality is significant. There is strong evidence that phages exert a significant pressure on the community structure and diversity and on the diversification of potential hosts, mainly through two major pathways: biogeochemical catalysis from lysis products and horizontal gene transfers. In turn, phages are sensitive to environmental factors, both in terms of integrity and of infectivity. Some phages contain typical viral genes that code for biological functions of interest, such as photosynthesis. In general, development in viral ecology is a source of new knowledge for the scientific community in the domain of environmental sciences, but also in the context of evolutionary biology of living cellular organisms, the obligatory hosts for viruses. For example, the recent discovery of a giant virus that becomes ill through infection by another virus (i.e., a viriophage) is fuelling debate about whether viruses are alive. Finally, future research directions are identified in the context of general aquatic ecology, including ecological researches on cyanophages and other phytoplanktonic phages as a priority, primarily in freshwater lakes.
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24
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Liu X, Kong S, Shi M, Fu L, Gao Y, An C. Genomic analysis of freshwater cyanophage Pf-WMP3 Infecting cyanobacterium Phormidium foveolarum: the conserved elements for a phage. MICROBIAL ECOLOGY 2008; 56:671-80. [PMID: 18443848 DOI: 10.1007/s00248-008-9386-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 02/17/2008] [Accepted: 02/20/2008] [Indexed: 05/14/2023]
Abstract
Cyanophages are ecologically abundant, genetically diverse in aquatic environments, and affect the population and evolutionary trajectories of their hosts. After reporting the cyanophage Pf-WMP4 genome (Liu et al. in Virology 366:28-39, 2007), we hereby present a related cyanophage, Pf-WMP3, which also infects the freshwater cyanobacterium Phormidium foveolarum. The Pf-WMP3 genome contains 43,249 bp with 234 bp direct terminal repeats. The overall genome organization and core genes of the two phages are comparable to those of the T7 supergroup phages. Compared with Pf-WMP4, cyanophage Pf-WMP3 has diverged extensively at the DNA level; however, they are closely related at the protein level and genome architecture. The left arm genes for the two phages, which mainly encode the DNA replication machinery, are not conserved in the gene order. Whereas the right arm genes of the two phages coding for structural proteins show high similarity in amino acid sequences and modular architecture, indicating that they have retained similar development strategies. The differences in similarity levels between the left and right arm genes suggest that the structural genes are the most conserved elements for a phage.
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Affiliation(s)
- Xinyao Liu
- National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China.
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25
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Comeau AM, Bertrand C, Letarov A, Tétart F, Krisch HM. Modular architecture of the T4 phage superfamily: a conserved core genome and a plastic periphery. Virology 2007; 362:384-96. [PMID: 17289101 DOI: 10.1016/j.virol.2006.12.031] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Revised: 12/04/2006] [Accepted: 12/13/2006] [Indexed: 11/22/2022]
Abstract
Among the most numerous objects in the biosphere, phages show enormous diversity in morphology and genetic content. We have sequenced 7 T4-like phages and compared their genome architecture. All seven phages share a core genome with T4 that is interrupted by several hyperplastic regions (HPRs) where most of their divergence occurs. The core primarily includes homologues of essential T4 genes, such as the virion structure and DNA replication genes. In contrast, the HPRs contain mostly novel genes of unknown function and origin. A few of the HPR genes that can be assigned putative functions, such as a series of novel Internal Proteins, are implicated in phage adaptation to the host. Thus, the T4-like genome appears to be partitioned into discrete segments that fulfil different functions and behave differently in evolution. Such partitioning may be critical for these large and complex phages to maintain their flexibility, while simultaneously allowing them to conserve their highly successful virion design and mode of replication.
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Affiliation(s)
- André M Comeau
- Laboratoire de Microbiologie et Génétique Moléculaire, CNRS-UMR5100, 31062 Toulouse Cedex 9, France
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26
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Duhamel S, Domaizon-Pialat I, Personnic S, Jacquet S. Assessing the microbial community dynamics and the role of bacteriophages in bacterial mortality in Lake Geneva. ACTA ACUST UNITED AC 2006. [DOI: 10.7202/013045ar] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
SummaryThe aims of this work were to study, for the first time, the succession of microbial communities (from viruses to ciliates) in the largest occidental European lake (Lake Geneva) and to perform two one-weekin situexperiments in March-April (Exp1) and May (Exp2) 2004 in order to assess both small flagellate protozoan and virus-induced mortality of heterotrophic bacteria. Both nanoflagellates and viruses could be responsible for 31 to 42% of the total daily mortality of heterotrophic bacteria. In May (Exp2), viruses could explain up to 10% of the bacterial mortality whereas flagellates were responsible for 32% of the bacterioplankton removal. These results provide new evidence for the critical role played by viruses in the functioning of the microbial food webs and highlight the importance of further considering this biological compartment for a better understanding of the plankton ecology of Lake Geneva.
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27
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Yan-Ming L, Xiu-Ping Y, Qi-Ya Z. Spatial distribution and morphologic diversity of virioplankton in Lake Donghu, China. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2006. [DOI: 10.1016/j.actao.2005.12.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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28
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Auguet JC, Montanié H, Lebaron P. Structure of virioplankton in the Charente Estuary (France): transmission electron microscopy versus pulsed field gel electrophoresis. MICROBIAL ECOLOGY 2006; 51:197-208. [PMID: 16463133 DOI: 10.1007/s00248-005-0043-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2005] [Accepted: 07/04/2005] [Indexed: 05/06/2023]
Abstract
Changes in the composition of viral communities were investigated along a salinity gradient and at different times by means of transmission electron microscopy (TEM) and pulsed field gel electrophoresis (PFGE). Samples were collected in fresh (Charente River), estuarine (Charente Estuary), and coastal (Pertuis d'Antioche, French Atlantic coast) waters. Both methods revealed similar patterns in viral community structure with a dominance of small viral particles (capsid and genome size). Viruses with a head size below 65 nm made up 71 +/- 5% of total virus-like particles, and virus-like genomes (VLG) below 100 kb accounted for 89 +/- 9% of total VLG. Despite this apparent stability of virioplankton composition over spatial scale (salinity gradient), the occurrence of large viruses (capsid and genome size) in estuarine and seawater samples indicated the presence of viral populations specific to a geographical location. Temporal changes in the structure (capsid and genome size) of viral communities were more pronounced than those reported at the spatial scale. From January to May 2003, seasonal changes in viral abundance and bacterial production occurred concomitantly with an increase in viral genomic diversity (richness), suggesting that virioplankton composition was strongly linked to changes in microbial activity and/or in the structure of the host communities. Although PFGE and TEM yielded complementary results in the description of virioplankton structures, it seems that the use of PFGE alone should be enough for the monitoring of community changes.
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Affiliation(s)
- J C Auguet
- Laboratoire de Biologie et Environnement Marins (LBEM, FRE 2727) CNRS, Université de La Rochelle, Avenue Michel Crépeau, 17042, La Rochelle, France. jcauguet@univ-lr-fr
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29
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Sano E, Carlson S, Wegley L, Rohwer F. Movement of viruses between biomes. Appl Environ Microbiol 2004; 70:5842-6. [PMID: 15466522 PMCID: PMC522096 DOI: 10.1128/aem.70.10.5842-5846.2004] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2004] [Accepted: 06/17/2004] [Indexed: 11/20/2022] Open
Abstract
Viruses are abundant in all known ecosystems. In the present study, we tested the possibility that viruses from one biome can successfully propagate in another. Viral concentrates were prepared from different near-shore marine sites, lake water, marine sediments, and soil. The concentrates were added to microcosms containing dissolved organic matter as a food source (after filtration to allow 100-kDa particles to pass through) and a 3% (vol/vol) microbial inoculum from a marine water sample (after filtration through a 0.45-microm-pore-size filter). Virus-like particle abundances were then monitored using direct counting. Viral populations from lake water, marine sediments, and soil were able to replicate when they were incubated with the marine microbes, showing that viruses can move between different ecosystems and propagate. These results imply that viruses can laterally transfer DNA between microbes in different biomes.
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Affiliation(s)
- Emiko Sano
- Center for Microbial Sciences, San Diego State University, 5500 Campanile Dr., San Diego, CA 92182, USA
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30
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Dorigo U, Jacquet S, Humbert JF. Cyanophage diversity, inferred from g20 gene analyses, in the largest natural lake in France, Lake Bourget. Appl Environ Microbiol 2004; 70:1017-22. [PMID: 14766584 PMCID: PMC348939 DOI: 10.1128/aem.70.2.1017-1022.2004] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The genetic diversity of the natural freshwater community of cyanophages and its variations over time have been investigated for the first time in the surface waters of the largest natural lake in France. This was done by random screening of clone libraries for the g20 gene and by denaturing gradient gel electrophoresis (DGGE). Nucleotide sequence analysis revealed 35 distinct cyanomyovirus g20 genotypes among the 47 sequences analyzed. Phylogenetic analyses showed that these sequences fell into seven genetically distinct operational taxonomic units (OTUs). The distances between these OTUs were comparable to those reported between marine clusters. Moreover, some of these freshwater cyanophage sequences were genetically more closely related to marine cyanophage sequences than to other freshwater sequences. Both approaches for the g20 gene (sequencing and DGGE analysis) showed that there was a clear seasonal pattern of variation in the composition of the cyanophage community that could reflect changes in its biological, chemical, and/or physical environment.
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Affiliation(s)
- Ursula Dorigo
- Equipe de Microbiologie Aquatique, Station INRA d'Hydrobiologie Lacustre, UMR CARRTEL, 74203 Thonon Cedex, France
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31
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Breitbart M, Wegley L, Leeds S, Schoenfeld T, Rohwer F. Phage community dynamics in hot springs. Appl Environ Microbiol 2004; 70:1633-40. [PMID: 15006788 PMCID: PMC368299 DOI: 10.1128/aem.70.3.1633-1640.2004] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In extreme thermal environments such as hot springs, phages are the only known microbial predators. Here we present the first study of prokaryotic and phage community dynamics in these environments. Phages were abundant in hot springs, reaching concentrations of a million viruses per milliliter. Hot spring phage particles were resistant to shifts to lower temperatures, possibly facilitating DNA transfer out of these extreme environments. The phages were actively produced, with a population turnover time of 1 to 2 days. Phage-mediated microbial mortality was significant, making phage lysis an important component of hot spring microbial food webs. Together, these results show that phages exert an important influence on microbial community structure and energy flow in extreme thermal environments.
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Affiliation(s)
- Mya Breitbart
- Department of Biology, San Diego State University, San Diego, California 92182-4614, USA
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Abstract
The morphological diversity of viruses which parasitize hyperthermophilic archaea thriving at temperatures > or = 80 degrees C appears to exceed that of viruses of prokaryotes living at lower temperatures. Based on assumptions of the existence of viruses in the prebiotic phase of evolution and hot origins of cellular life, we suggest that this remarkable diversity could have its source in ancestral diversity of viral morphotypes in hot environments. Attempts are made to trace evolutionary relationships of viruses of hyperthermophilic archaea with other viruses.
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Affiliation(s)
- David Prangishvili
- Lehrstuhl für Mikrobiologie und Archaeenzentrum, Universität Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany.
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Wolf A, Wiese J, Jost G, Witzel KP. Wide geographic distribution of bacteriophages that lyse the same indigenous freshwater isolate (Sphingomonas sp. strain B18). Appl Environ Microbiol 2003; 69:2395-8. [PMID: 12676728 PMCID: PMC154766 DOI: 10.1128/aem.69.4.2395-2398.2003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An indigenous freshwater bacterium (Sphingomonas sp. strain B18) from Lake Plubetasee (Schleswig-Holstein, Germany) was used to isolate 44 phages from 13 very different freshwater and brackish habitats in distant geographic areas. This bacterial strain was very sensitive to a broad spectrum of phages from different aquatic environments. Phages isolated from geographically distant aquatic habitats, but also those from the same sample, were diverse with respect to morphology and restriction pattern. Some phages were widely distributed, while different types coexisted in the same sample. It was concluded that phages could be a major factor in shaping the structure of bacterial communities and maintaining a high bacterial diversity.
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Affiliation(s)
- Arite Wolf
- Max Planck Institute for Limnology, 24302 Plön, Germany
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Morita M, Tanji Y, Mizoguchi K, Soejima A, Orito Y, Unno H. Antibacterial activity of Bacillus amyloliquefaciens phage endolysin without holin conjugation. J Biosci Bioeng 2001. [DOI: 10.1016/s1389-1723(01)80275-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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35
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Abstract
The discovery that viruses may be the most abundant organisms in natural waters, surpassing the number of bacteria by an order of magnitude, has inspired a resurgence of interest in viruses in the aquatic environment. Surprisingly little was known of the interaction of viruses and their hosts in nature. In the decade since the reports of extraordinarily large virus populations were published, enumeration of viruses in aquatic environments has demonstrated that the virioplankton are dynamic components of the plankton, changing dramatically in number with geographical location and season. The evidence to date suggests that virioplankton communities are composed principally of bacteriophages and, to a lesser extent, eukaryotic algal viruses. The influence of viral infection and lysis on bacterial and phytoplankton host communities was measurable after new methods were developed and prior knowledge of bacteriophage biology was incorporated into concepts of parasite and host community interactions. The new methods have yielded data showing that viral infection can have a significant impact on bacteria and unicellular algae populations and supporting the hypothesis that viruses play a significant role in microbial food webs. Besides predation limiting bacteria and phytoplankton populations, the specific nature of virus-host interaction raises the intriguing possibility that viral infection influences the structure and diversity of aquatic microbial communities. Novel applications of molecular genetic techniques have provided good evidence that viral infection can significantly influence the composition and diversity of aquatic microbial communities.
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Affiliation(s)
- K E Wommack
- Center of Marine Biotechnology, Baltimore, Maryland 21202, USA
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36
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Muniesa M, Lucena F, Jofre J. Study of the potential relationship between the morphology of infectious somatic coliphages and their persistence in the environment. J Appl Microbiol 1999; 87:402-9. [PMID: 10540243 DOI: 10.1046/j.1365-2672.1999.00833.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The proportions of different morphological types of infectious somatic coliphages were determined in faecally polluted freshwaters. Myoviridae, followed by Siphoviridae, were the most frequently isolated morphological types in raw sewage, treated sewage and river water collected a few metres downstream from a sewage outfall. However, in river water collected further downstream from the pollution point, in river water after 'in situ' inactivation experiments and in chlorinated raw and treated sewage significant changes in the proportions of the different somatic coliphage morphological types occurred. In all cases, Siphoviridae, especially those with flexible and curled tails, became more abundant to the detriment of Myoviridae.
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Affiliation(s)
- M Muniesa
- Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Spain
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Population dynamics of chesapeake bay virioplankton: total-community analysis by pulsed-field gel electrophoresis. Appl Environ Microbiol 1999; 65:231-40. [PMID: 9872784 PMCID: PMC91007 DOI: 10.1128/aem.65.1.231-240.1999] [Citation(s) in RCA: 143] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recognition of viruses as the most abundant component of aquatic microbial communities has stimulated investigations of the impact of viruses on bacterio- and phytoplankton host communities. From results of field studies to date, it is concluded that in most aquatic environments, a reduction in the number of bacteria on a daily basis is caused by viral infection. However, the modest amount of in situ virus-mediated mortality may be less significant than viral infection serving to maintain clonal diversity in the host communities directly, through gene transmission (i.e., transduction), and indirectly, by elimination of numerically dominant host species. If the latter mechanism for controlling community diversity prevails, then the overall structure of aquatic viral communities would be expected to change as well over short seasonal and spatial scales. To determine whether this occurs, pulsed-field gel electrophoresis (PFGE) was used to monitor the population dynamics of Chesapeake Bay virioplankton for an annual cycle (1 year). Virioplankton in water samples collected at six stations along a transect running the length of the bay were concentrated 100-fold by ultrafiltration. Viruses were further concentrated by ultracentrifugation, and the concentrated samples were embedded in agarose. PFGE analysis of virus DNA in the agarose plugs yielded several distinct bands, ranging from 50 to 300 kb. Principal-component and cluster analyses of the virus PFGE fingerprints indicated that changes in virioplankton community structure were correlated with time, geographical location, and extent of water column stratification. From the results of this study, it is concluded that, based on the dynamic nature of the Chesapeake Bay virioplankton community structure, the clonal diversity of bacterio- and phytoplankton host communities is an important component of the virus community.
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Abstract
Seasonal changes in the abundance of inducible lysogenic bacteria in a eutrophic estuarine environment were investigated over a 13-month period. Biweekly water samples were collected from Tampa Bay, Fla., and examined for prophage induction by mitomycin C treatment. At the conclusion of the study, we determined that 52.2% of the samples displayed prophage induction, as indicated by significant increases in viral direct counts compared with uninduced controls. Samples that displayed prophage induction occurred during the warmer months (February through October), when surface water temperatures were above 19 degreesC, and no induction was observed in November, December, or January. This study presents clear evidence that there is seasonal variation in the number of inducible lysogenic bacteria in an estuarine environment.
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Weinbauer MG, Höfle MG. Significance of viral lysis and flagellate grazing as factors controlling bacterioplankton production in a eutrophic lake. Appl Environ Microbiol 1998; 64:431-8. [PMID: 16349497 PMCID: PMC106062 DOI: 10.1128/aem.64.2.431-438.1998] [Citation(s) in RCA: 168] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/1997] [Accepted: 11/14/1997] [Indexed: 11/20/2022] Open
Abstract
The effects of viral lysis and heterotrophic nanoflagellate (HNF) grazing on bacterial mortality were estimated in a eutrophic lake (Lake Plusssee in northern Germany) which was separated by a steep temperature and oxygen gradient into a warm and oxic epilimnion and a cold and anoxic hypolimnion. Two transmission electron microscopy-based methods (whole-cell examination and thin sections) were used to determine the frequency of visibly infected cells, and a model was used to estimate bacterial mortality due to viral lysis. Examination of thin sections also showed that between 20.2 and 29.2% (average, 26.1%) of the bacterial cells were empty (ghosts) and thus could not contribute to viral production. The most important finding was that the mechanism for regulating bacterial production shifted with depth from grazing control in the epilimnion to control due to viral lysis in the hypolimnion. We estimated that in the epilimnion viral lysis accounted on average for 8.4 to 41.8% of the summed mortality (calculated by determining the sum of the mortalities due to lysis and grazing), compared to 51.3 to 91.0% of the summed mortality in the metalimninon and 88.5 to 94.2% of the summed mortality in the hypolimnion. Estimates of summed mortality values indicated that bacterial production was controlled completely or almost completely in the epilimnion (summed mortality, 66.6 to 128.5%) and the hypolimnion (summed mortality, 43.4 to 103.3%), whereas in the metalimnion viral lysis and HNF grazing were not sufficient to control bacterial production (summed mortality, 22.4 to 56.7%). The estimated contribution of organic matter released by viral lysis of cells into the pool of dissolved organic matter (DOM) was low; however, since cell lysis products are very likely labile compared to the bulk DOM, they might stimulate bacterial production. The high mortality of bacterioplankton due to viral lysis in anoxic water indicates that a significant portion of bacterial production in the metalimnion and hypolimnion is cycled in the bacterium-virus-DOM loop. This finding has major implications for the fate and cycling of organic nutrients in lakes.
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Affiliation(s)
- M G Weinbauer
- GBF-National Research Center of Biotechnology, AG Molecular Microbial Ecology, D-38124 Braunschweig, Germany
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Mathias CB, Kirschner A, Velimirov B. Seasonal variations of virus abundance and viral control of the bacterial production in a backwater system of the danube river. Appl Environ Microbiol 1995; 61:3734-40. [PMID: 16535153 PMCID: PMC1388715 DOI: 10.1128/aem.61.10.3734-3740.1995] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The abundance of virus-like particles in a backwater system of the Danube River covered a range of 1.2 x 10(sup7) to 6.1 x 10(sup7) ml(sup-1) from 1992 to 1993. Measurements of head diameters for these particles, all of which were presumed to be viruses, led to four defined size classes, ranging from <60 nm to >150 nm. The 60- to <90-nm size class contained the largest fraction of total particles (41%), followed by the 90- to <150-nm size class (33%). The frequency of size classes was not significantly different between the two years. The frequency of bacteria with mature phages ranged from 1 to 4% over the seasons, with mean burst sizes ranging from 17 to 36 phage per host cell. Among the bacterial morphotypes, rods and vibrios were the major host systems for phages, while coccoid and filamentous cells were considered negligible. Counts from transmission electron microscopy and acridine orange direct counts confirmed that rods and vibrios accounted for 85 to 95% of the bacterial population over the seasons. Virus decay experiments showed lower decay rates for temperatures between 5 and 15(deg)C (52 to 70% of the virus population remained) relative to 18 and 25(deg)C (31 to 51% of the virus remained). Bacterial production measurements, performed at the same time and under the same conditions as decay experiments, allowed us to estimate virus-induced death rates, which ranged from 15.8 to 30.1% over the year, with an average of 20% viral control of the bacterial production. Considering that mature phage particles are visible only in the last phase of the latent period and using a mean conversion factor of 5.4 from the literature, based on descriptions of various phage host systems to relate the percentage of visibly infected cells to the total percentage of the bacterial community that is phage infected, we estimate that some 5.4 to 21.6% of the bacterial population is infected with viruses. This would imply that virus-induced death rates of bacteria range from 10.8 to 43.2%. The data on virus-induced bacterial mortality obtained by both the viral decay method and the determination of the frequency of infected cells are compared and discussed.
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