1
|
Gomathinayagam S, Kodiveri Muthukaliannan G. Dynamics of antibiotic resistance genes in plasmids and bacteriophages. Crit Rev Microbiol 2024:1-10. [PMID: 38651513 DOI: 10.1080/1040841x.2024.2339262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 04/01/2024] [Indexed: 04/25/2024]
Abstract
This brief review explores the intricate interplay between bacteriophages and plasmids in the context of antibiotic resistance gene (ARG) dissemination. Originating from studies in the late 1950s, the review traces the evolution of knowledge regarding extrachromosomal factors facilitating horizontal gene transfer and adaptation in bacteria. Analyzing the gene repertoires of plasmids and bacteriophages, the study highlights their contributions to bacterial evolution and adaptation. While plasmids encode essential and accessory genes influencing host characteristics, bacteriophages carry auxiliary metabolic genes (AMGs) that augment host metabolism. The debate on phages carrying ARGs is explored through a critical evaluation of various studies, revealing contrasting findings from researchers. Additionally, the review addresses the interplay between prophages and plasmids, underlining their similarities and divergences. Based on the available literature evidence, we conclude that plasmids generally encode ARGs while bacteriophages typically do not contain ARGs. But extra-chromosomaly present prophages with plasmid characteristics can encode and disseminate ARGs.
Collapse
|
2
|
Guerrero-Bustamante CA, Hatfull GF. Bacteriophage tRNA-dependent lysogeny: requirement of phage-encoded tRNA genes for establishment of lysogeny. mBio 2024; 15:e0326023. [PMID: 38236026 PMCID: PMC10865867 DOI: 10.1128/mbio.03260-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 12/11/2023] [Indexed: 01/19/2024] Open
Abstract
Bacteriophages are large and diverse components of the biosphere, and many phages are temperate. Upon infection, temperate phages can establish lysogeny in which a prophage is typically integrated into the bacterial chromosome. Here, we describe the phenomenon of tRNA-dependent lysogeny, a previously unrecognized behavior of some temperate phages. tRNA-dependent lysogeny is characterized by two unusual features. First, a phage-encoded tyrosine family integrase mediates site-specific recombination between a phage attP site and a bacterial attB site overlapping a host tRNA gene. However, attP and attB share only a short (~10 bp) common core such that a functional tRNA is not reconstructed upon integration. Second, the phage encodes a tRNA of the same isotype as the disrupted but essential host tRNA, complementing its loss, and consequently is required for the survival of lysogenic progeny. As expected, an integrase-defective phage mutant forms turbid plaques, and bacterial progeny are immune to superinfection, but they lack stability, and the prophage is rapidly lost. In contrast, a tRNA-defective phage mutant forms clear plaques and more closely resembles a repressor mutant, and lysogens are recovered only at very low frequency through the use of secondary attachment sites elsewhere in the host genome. Integration-proficient plasmids derived from these phages must also carry a cognate phage tRNA gene for efficient integration, and these may be useful tools for mycobacterial genetics. We show that tRNA-dependent lysogeny is used by phages within multiple different groups of related viruses and may be prevalent elsewhere in the broader phage community.IMPORTANCEBacteriophages are the most numerous biological entities in the biosphere, and a substantial proportion of phages are temperate, forming stable lysogens in which a prophage copy of the genome integrates into the bacterial chromosome. Many phages encode a variety of tRNA genes whose roles are poorly understood, although it has been proposed that they enhance translational efficiencies in lytic growth or that they counteract host defenses that degrade host tRNAs. Here, we show that phage-encoded tRNAs play key roles in the establishment of lysogeny of some temperate phages. They do so by compensating for the loss of tRNA function when phages integrate at an attB site overlapping a tRNA gene but fail to reconstruct the tRNA at the attachment junction. In this system of tRNA-dependent lysogeny, the phage-encoded tRNA is required for lysogeny, and deletion of the phage tRNA gives rise to a clear plaque phenotype and obligate lytic growth.
Collapse
Affiliation(s)
| | - Graham F. Hatfull
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
3
|
Abad L, Gauthier CH, Florian I, Jacobs-Sera D, Hatfull GF. The heterogenous and diverse population of prophages in Mycobacterium genomes. mSystems 2023; 8:e0044623. [PMID: 37791767 PMCID: PMC10654092 DOI: 10.1128/msystems.00446-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/18/2023] [Indexed: 10/05/2023] Open
Abstract
IMPORTANCE Mycobacterium species include several human pathogens and mycobacteriophages show potential for therapeutic use to control Mycobacterium infections. However, phage infection profiles vary greatly among Mycobacterium abscessus clinical isolates and phage therapies must be personalized for individual patients. Mycobacterium phage susceptibility is likely determined primarily by accessory parts of bacterial genomes, and we have identified the prophage and phage-related genomic regions across sequenced Mycobacterium strains. The prophages are numerous and diverse, especially in M. abscessus genomes, and provide a potentially rich reservoir of new viruses that can be propagated lytically and used to expand the repertoire of therapeutically useful phages.
Collapse
Affiliation(s)
- Lawrence Abad
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Christian H. Gauthier
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Isabella Florian
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Deborah Jacobs-Sera
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Graham F. Hatfull
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
4
|
Ilyas SZ, Tariq H, Basit A, Tahir H, Haider Z, Rehman SU. SGP-C: A Broad Host Range Temperate Bacteriophage; Against Salmonella gallinarum. Front Microbiol 2022; 12:768931. [PMID: 35095790 PMCID: PMC8790156 DOI: 10.3389/fmicb.2021.768931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 12/03/2021] [Indexed: 11/13/2022] Open
Abstract
Salmonella gallinarum is a poultry restricted-pathogen causing fowl-typhoid disease in adult birds with mortality rates up-to 80% and exhibit resistance against commonly used antibiotics. In this current study, a temperate broad host range bacteriophage SGP-C was isolated against S. gallinarum from poultry digesta. It showed infection ability in all the 15 tested field strains of S. gallinarum. The SGP-C phage produced circular, turbid plaques with alternate rings. Its optimum activity was observed at pH 7.0 and 37-42°C, with a latent period of 45 min and burst size of 187 virions/bacterial cell. The SGP-C lysogens, SGPC-L5 and SGPC-L6 exhibited super-infection immunity against the same phage, an already reported feature of lysogens. A virulence index of 0.5 and 0.001 as MV50 of SGP-C suggests its moderate virulence. The genome of SGP-C found circular double stranded DNA of 42 Kbp with 50.04% GC content, which encodes 63 ORFs. The presence of repressor gene at ORF49, and absence of tRNA sequence in SGP-C genome indicates its lysogenic nature. Furthermore, from NGS analysis of lysogens we propose that SGP-C genome might exist either as an episome, or both as integrated and temporary episome in the host cell and warrants further studies. Phylogenetic analysis revealed its similarity with Salmonella temperate phages belonging to family Siphoviridae. The encoded proteins by SGP-C genome have not showed homology with any known toxin and virulence factor. Although plenty of lytic bacteriophages against this pathogen are already reported, to our knowledge SGP-C is the first lysogenic phage against S. gallinarum reported so far.
Collapse
Affiliation(s)
| | | | | | | | | | - Shafiq ur Rehman
- Institute of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan
| |
Collapse
|
5
|
Hatoum-Aslan A. The phages of staphylococci: critical catalysts in health and disease. Trends Microbiol 2021; 29:1117-1129. [PMID: 34030968 PMCID: PMC8578144 DOI: 10.1016/j.tim.2021.04.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/26/2021] [Accepted: 04/28/2021] [Indexed: 01/21/2023]
Abstract
The phages that infect Staphylococcus species are dominant residents of the skin microbiome that play critical roles in health and disease. While temperate phages, which can integrate into the host genome, have the potential to promote staphylococcal pathogenesis, the strictly lytic variety are powerful antimicrobials that are being exploited for therapeutic applications. This article reviews recent insights into the diversity of staphylococcal phages and newly described mechanisms by which they influence host pathogenicity. The latest efforts to harness these viruses to eradicate staphylococcal infections are also highlighted. Decades of research has focused on the temperate phages of Staphylococcus aureus as model systems, thus underscoring the need to broaden basic research efforts to include diverse phages that infect other clinically relevant Staphylococcus species.
Collapse
Affiliation(s)
- Asma Hatoum-Aslan
- University of Illinois at Urbana-Champaign, Department of Microbiology, Urbana, IL, 61801, USA.
| |
Collapse
|
6
|
Rohmer C, Wolz C. The Role of hlb-Converting Bacteriophages in Staphylococcus aureus Host Adaption. Microb Physiol 2021; 31:109-122. [PMID: 34126612 DOI: 10.1159/000516645] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 04/17/2021] [Indexed: 11/19/2022]
Abstract
As an opportunistic pathogen of humans and animals, Staphylococcus aureus asymptomatically colonizes the nasal cavity but is also a leading cause of life-threatening acute and chronic infections. The evolution of S. aureus resulting from short- and long-term adaptation to diverse hosts is tightly associated with mobile genetic elements. S. aureus strains can carry up to four temperate phages, many of which possess accessory genes encoding staphylococcal virulence factors. More than 90% of human nasal isolates of S. aureus have been shown to carry Sa3int phages, whereas invasive S. aureus isolates tend to lose these phages. Sa3int phages integrate as prophages into the bacterial hlb gene, disrupting the expression of the sphingomyelinase Hlb, an important virulence factor under specific infection conditions. Virulence factors encoded by genes carried by Sa3int phages include staphylokinase, enterotoxins, chemotaxis-inhibitory protein, and staphylococcal complement inhibitor, all of which are highly human specific and probably essential for bacterial survival in the human host. The transmission of S. aureus from humans to animals is strongly correlated with the loss of Sa3int phages, whereas phages are regained once a strain is transmitted from animals to humans. Thus, both the insertion and excision of prophages may confer a fitness advantage to this bacterium. There is also growing evidence that Sa3int phages may perform "active lysogeny," a process during which prophages are temporally excised from the chromosome without forming intact phage particles. The molecular mechanisms controlling the peculiar life cycle of Sa3int phages remain largely unclear. Nevertheless, their regulation is likely fine-tuned to ensure bacterial survival within different hosts.
Collapse
Affiliation(s)
- Carina Rohmer
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany
| | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany.,Cluster of Excellence EXC 2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| |
Collapse
|
7
|
Orellana R, Arancibia A, Badilla L, Acosta J, Arancibia G, Escar R, Ferrada G, Seeger M. Ecophysiological Features Shape the Distribution of Prophages and CRISPR in Sulfate Reducing Prokaryotes. Microorganisms 2021; 9:microorganisms9050931. [PMID: 33925267 PMCID: PMC8146710 DOI: 10.3390/microorganisms9050931] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 04/18/2021] [Accepted: 04/23/2021] [Indexed: 12/28/2022] Open
Abstract
Sulfate reducing prokaryotes (SRP) are a phylogenetically and physiologically diverse group of microorganisms that use sulfate as an electron acceptor. SRP have long been recognized as key players of the carbon and sulfur cycles, and more recently, they have been identified to play a relevant role as part of syntrophic and symbiotic relations and the human microbiome. Despite their environmental relevance, there is a poor understanding about the prevalence of prophages and CRISPR arrays and how their distribution and dynamic affect the ecological role of SRP. We addressed this question by analyzing the results of a comprehensive survey of prophages and CRISPR in a total of 91 genomes of SRP with several genotypic, phenotypic, and physiological traits, including genome size, cell volume, minimum doubling time, cell wall, and habitat, among others. Our analysis discovered 81 prophages in 51 strains, representing the 56% of the total evaluated strains. Prophages are non-uniformly distributed across the SRP phylogeny, where prophage-rich lineages belonged to Desulfovibrionaceae and Peptococcaceae. Furthermore, our study found 160 CRISPR arrays in 71 SRP, which is more abundant and widely spread than previously expected. Although there is no correlation between presence and abundance of prophages and CRISPR arrays at the strain level, our analysis showed that there is a directly proportional relation between cellular volumes and number of prophages per cell. This result suggests that there is an additional selective pressure for strains with smaller cells to get rid of foreign DNA, such as prophages, but not CRISPR, due to less availability of cellular resources. Analysis of the prophage genes encoding viral structural proteins reported that 44% of SRP prophages are classified as Myoviridae, and comparative analysis showed high level of homology, but not synteny, among prophages belonging to the Family Desulfovibrionaceae. We further recovered viral-like particles and structures that resemble outer membrane vesicles from D. vulgaris str. Hildenborough. The results of this study improved the current understanding of dynamic interactions between prophages and CRISPR with their hosts in both cultured and hitherto-uncultured SRP strains, and how their distribution affects the microbial community dynamics in several sulfidogenic natural and engineered environments.
Collapse
Affiliation(s)
- Roberto Orellana
- Laboratorio de Biología Celular y Ecofisiología Microbiana, Facultad de Ciencias Naturales y Exactas, Universidad de Playa Ancha, Leopoldo Carvallo 270, Valparaíso 2360001, Chile; (A.A.); (L.B.)
- Correspondence:
| | - Alejandra Arancibia
- Laboratorio de Biología Celular y Ecofisiología Microbiana, Facultad de Ciencias Naturales y Exactas, Universidad de Playa Ancha, Leopoldo Carvallo 270, Valparaíso 2360001, Chile; (A.A.); (L.B.)
| | - Leonardo Badilla
- Laboratorio de Biología Celular y Ecofisiología Microbiana, Facultad de Ciencias Naturales y Exactas, Universidad de Playa Ancha, Leopoldo Carvallo 270, Valparaíso 2360001, Chile; (A.A.); (L.B.)
| | - Jonathan Acosta
- Departamento de Estadística, Pontificia Universidad Católica de Chile, Avda. Vicuña Mackenna 4860, Santiago 7820436, Chile;
| | - Gabriela Arancibia
- Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Centro de Biotecnología Daniel Alkalay-Lowitt, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2390123, Chile; (G.A.); (R.E.); (G.F.); (M.S.)
| | - Rodrigo Escar
- Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Centro de Biotecnología Daniel Alkalay-Lowitt, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2390123, Chile; (G.A.); (R.E.); (G.F.); (M.S.)
| | - Gustavo Ferrada
- Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Centro de Biotecnología Daniel Alkalay-Lowitt, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2390123, Chile; (G.A.); (R.E.); (G.F.); (M.S.)
| | - Michael Seeger
- Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Centro de Biotecnología Daniel Alkalay-Lowitt, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2390123, Chile; (G.A.); (R.E.); (G.F.); (M.S.)
| |
Collapse
|
8
|
Blattman SB, Jiang W, Oikonomou P, Tavazoie S. Prokaryotic single-cell RNA sequencing by in situ combinatorial indexing. Nat Microbiol 2020; 5:1192-1201. [PMID: 32451472 PMCID: PMC8330242 DOI: 10.1038/s41564-020-0729-6] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 04/23/2020] [Indexed: 02/06/2023]
Abstract
Despite longstanding appreciation of gene expression heterogeneity in isogenic bacterial populations, affordable and scalable technologies for studying single bacterial cells have been limited. Although single-cell RNA sequencing (scRNA-seq) has revolutionized studies of transcriptional heterogeneity in diverse eukaryotic systems1-13, the application of scRNA-seq to prokaryotes has been hindered by their extremely low mRNA abundance14-16, lack of mRNA polyadenylation and thick cell walls17. Here, we present prokaryotic expression profiling by tagging RNA in situ and sequencing (PETRI-seq)-a low-cost, high-throughput prokaryotic scRNA-seq pipeline that overcomes these technical obstacles. PETRI-seq uses in situ combinatorial indexing11,12,18 to barcode transcripts from tens of thousands of cells in a single experiment. PETRI-seq captures single-cell transcriptomes of Gram-negative and Gram-positive bacteria with high purity and low bias, with median capture rates of more than 200 mRNAs per cell for exponentially growing Escherichia coli. These characteristics enable robust discrimination of cell states corresponding to different phases of growth. When applied to wild-type Staphylococcus aureus, PETRI-seq revealed a rare subpopulation of cells undergoing prophage induction. We anticipate that PETRI-seq will have broad utility in defining single-cell states and their dynamics in complex microbial communities.
Collapse
Affiliation(s)
- Sydney B Blattman
- Department of Biological Sciences, Columbia University, New York City, NY, USA
- Department of Systems Biology, Columbia University, New York City, NY, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York City, NY, USA
| | - Wenyan Jiang
- Department of Biological Sciences, Columbia University, New York City, NY, USA
- Department of Systems Biology, Columbia University, New York City, NY, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York City, NY, USA
| | - Panos Oikonomou
- Department of Biological Sciences, Columbia University, New York City, NY, USA
- Department of Systems Biology, Columbia University, New York City, NY, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York City, NY, USA
| | - Saeed Tavazoie
- Department of Biological Sciences, Columbia University, New York City, NY, USA.
- Department of Systems Biology, Columbia University, New York City, NY, USA.
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York City, NY, USA.
| |
Collapse
|
9
|
Brassil B, Mores CR, Wolfe AJ, Putonti C. Characterization and spontaneous induction of urinary tract Streptococcus anginosus prophages. J Gen Virol 2020; 101:685-691. [PMID: 32310742 PMCID: PMC7414447 DOI: 10.1099/jgv.0.001407] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 02/21/2020] [Indexed: 01/08/2023] Open
Abstract
Streptococcus anginosus is an often overlooked and understudied emerging pathogen inhabiting many areas of the human body. Through our sequencing of S. anginosus strains isolated from the female bladder microbiota, we detected numerous prophage sequences. Bioinformatic analysis of these sequences identified 17 distinct groups of S. anginosus prophages. The majority of these phages exhibit no sequence homology to previously characterized temperate or virulent phage sequences, indicating an unexplored diversity of Streptococcus phages. By culturing these bacterial isolates, we confirmed that the prophages of five of these groups are capable of induction. One of these putative phages was imaged, the first such evidence of an S. anginosus virus-like particle; it exhibits morphological characteristics of siphoviruses.
Collapse
Affiliation(s)
- Bridget Brassil
- Department of Biology, Loyola University Chicago, Chicago, IL 60660, USA
| | - Carine R. Mores
- Department of Biology, Loyola University Chicago, Chicago, IL 60660, USA
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Alan J. Wolfe
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Catherine Putonti
- Department of Biology, Loyola University Chicago, Chicago, IL 60660, USA
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
- Department of Computer Science, Loyola University Chicago, Chicago, IL 60660, USA
- Bioinformatics Program, Loyola University Chicago, Chicago, IL 60660, USA
| |
Collapse
|
10
|
Abstract
Bacteriophages are the most abundant biological entities in the biosphere and are a source of uncharacterized biological mechanisms and genetic tools. Here, we identify segments of phage genomes that are used for stable extrachromosomal replication in the prophage state. Autonomous replication of some of these phages requires a RepA-like protein, although most lack repA and use RNA-based systems for replication initiation. We describe a suite of plasmids based on these prophage replication functions that vary in copy number, stability, host range, and compatibility. These plasmids expand the toolbox available for genetic manipulation of Mycobacterium and other Actinobacteria, including Gordonia terrae. Temperate bacteriophages are common and establish lysogens of their bacterial hosts in which the prophage is stably inherited. It is typical for such prophages to be integrated into the bacterial chromosome, but extrachromosomally replicating prophages have been described also, with the best characterized being the Escherichia coli phage P1 system. Among the large collection of sequenced mycobacteriophages, more than half are temperate or predicted to be temperate, most of which code for a tyrosine or serine integrase that promotes site-specific prophage integration. However, within the large group of 621 cluster A temperate phages, ∼20% lack an integration cassette, which is replaced with a parABS partitioning system. A subset of these phages carry genes coding for a RepA-like protein (RepA phages), which we show here is necessary and sufficient for autonomous extrachromosomal replication. The non-RepA phages appear to replicate using an RNA-based system, as a parABS-proximal region expressing a noncoding RNA is required for replication. Both RepA and non-RepA phage-based plasmids replicate at one or two copies per cell, transform both Mycobacterium smegmatis and Mycobacterium tuberculosis, and are compatible with pAL5000-derived oriM and integration-proficient plasmid vectors. Characterization of these phage-based plasmids offers insights into the variability of lysogenic maintenance systems and provides a large suite of plasmids for actinobacterial genetics that vary in stability, copy number, compatibility, and host range.
Collapse
|
11
|
Wang F, Wang D, Hou W, Jin Q, Feng J, Zhou D. Evolutionary Diversity of Prophage DNA in Klebsiella pneumoniae Chromosomes. Front Microbiol 2019; 10:2840. [PMID: 31866991 PMCID: PMC6908951 DOI: 10.3389/fmicb.2019.02840] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 11/22/2019] [Indexed: 12/20/2022] Open
Abstract
Mobile gene elements play an important role in the continuous evolution of the prophage DNA of bacteria, promoting the emergence of new gene structures. This study explored the evolution of four strains of Klebsiella pneumoniae harboring prophages, 19051, 721005, 911021, and 675920, and 16 genomes of K. pneumoniae from GenBank. The results revealed a wide range of genetic variation in the prophage DNA inserted into the sap sites of K. pneumoniae chromosomes. From analysis and comparison of the sequences of the 20 prophage DNAs determined from the four strains and the 16 GenBank genomes of K. pneumoniae using high-throughput sequencing and antimicrobial susceptibility tests, we identified a novel transposon, Tn6556. We also identified at least nine large genetic structures with massive genetic acquisitions or losses and five hotspot sites showing a tendency to undergo insertion of gene elements such as IS1T, IS1R, IS26, ISKpn26, ISKpn28, Tn6556, MDR, and In27-related regions as variable regions; however, the only highly conserved core genes were int and umuCD among the 20 prophage DNAs. These findings provide important insights into the evolutionary diversity of bacteriophage DNA contained in K. pneumoniae.
Collapse
Affiliation(s)
- Fengling Wang
- Department of Infectious Disease, Taizhou Municipal Hospital, Taizhou University, Taizhou, China
| | - Dongguo Wang
- Department of Clinical Laboratory Medicine, Taizhou Municipal Hospital, Taizhou University, Taizhou, China
| | - Wei Hou
- Department of Infectious Disease, Taizhou Municipal Hospital, Taizhou University, Taizhou, China
| | - Qian Jin
- Department of Infectious Disease, Taizhou Municipal Hospital, Taizhou University, Taizhou, China
| | - Jiao Feng
- Institute of Biomedical Sciences, Shanxi University, Taiyuan, China
| | - Dongsheng Zhou
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| |
Collapse
|
12
|
Genome Sequences of Six Prophages Isolated from Staphylococcus pseudintermedius Strains Recovered from Human and Animal Clinical Specimens. Microbiol Resour Announc 2019; 8:8/28/e00387-19. [PMID: 31296676 PMCID: PMC6624759 DOI: 10.1128/mra.00387-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Staphylococcus pseudintermedius is a common bacterial pathogen in companion animal medicine and has demonstrated zoonotic potential. Here, we report six new Staphylococcus pseudintermedius prophage genomes of the Siphoviridae family, identified in isolates recovered from human and canine clinical specimens. Staphylococcus pseudintermedius is a common bacterial pathogen in companion animal medicine and has demonstrated zoonotic potential. Here, we report six new Staphylococcus pseudintermedius prophage genomes of the Siphoviridae family, identified in isolates recovered from human and canine clinical specimens.
Collapse
|
13
|
ϕSa3mw Prophage as a Molecular Regulatory Switch of Staphylococcus aureus β-Toxin Production. J Bacteriol 2019; 201:JB.00766-18. [PMID: 30962356 PMCID: PMC6597384 DOI: 10.1128/jb.00766-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 04/01/2019] [Indexed: 11/20/2022] Open
Abstract
Phage regulatory switches (phage-RSs) are a newly described form of active lysogeny where prophages function as regulatory mechanisms for expression of chromosomal bacterial genes. In Staphylococcus aureus, ϕSa3int is a widely distributed family of prophages that integrate into the β-toxin structural gene hlb, effectively inactivating it. However, β-toxin-producing strains often arise during infections and are more virulent in experimental infective endocarditis and pneumonia infections. We present evidence that in S. aureus MW2, ϕSa3mw excision is temporally and differentially responsive to growth conditions relevant to S. aureus pathogenesis. PCR analyses of ϕSa3mw (integrated and excised) and of intact hlb showed that ϕSa3mw preferentially excises in response to hydrogen peroxide-induced oxidative stress and during biofilm growth. ϕSa3mw remains as a prophage when in contact with human aortic endothelial cells in culture. A criterion for a prophage to be considered a phage-RS is the inability to lyse host cells. MW2 grown under phage-inducing conditions did not release infectious phage particles by plaque assay or transmission electron microscopy, indicating that ϕSa3mw does not carry out a productive lytic cycle. These studies highlight a dynamic, and perhaps more sophisticated, S. aureus-prophage interaction where ϕSa3int prophages provide a novel regulatory mechanism for the conditional expression of virulence factors.IMPORTANCE β-Toxin is a sphingomyelinase hemolysin that significantly contributes to Staphylococcus aureus pathogenesis. In most S. aureus isolates the prophage ϕSa3int inserts into the β-toxin gene hlb, inactivating it, but human and experimental infections give rise to β-toxin-producing variants. However, it remained to be established whether ϕSa3mw excises in response to specific environmental cues, restoring the β-toxin gene sequence. This is not only of fundamental interest but also critical when designing intervention strategies and therapeutics. We provide evidence that ϕSa3mw actively excises, allowing the conditional expression of β-toxin. ϕSa3int prophages may play a novel and largely uncharacterized role in S. aureus pathogenesis as molecular regulatory switches that promote bacterial fitness and adaptation to the challenges presented by the mammalian host.
Collapse
|