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Wang Y, Xuan G, Ning H, Kong J, Lin H, Wang J. Tn5 Transposon-based Mutagenesis for Engineering Phage-resistant Strains of Escherichia coli BL21 (DE3). J Microbiol 2023:10.1007/s12275-023-00048-2. [PMID: 37213024 DOI: 10.1007/s12275-023-00048-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 04/05/2023] [Accepted: 04/12/2023] [Indexed: 05/23/2023]
Abstract
Escherichia coli is a preferred strain for recombinant protein production, however, it is often plagued by phage infection during experimental studies and industrial fermentation. While the existing methods of obtaining phage-resistant strains by natural mutation are not efficient enough and time-consuming. Herein, a high-throughput method by combining Tn5 transposon mutation and phage screening was used to produce Escherichia coli BL21 (DE3) phage-resistant strains. Mutant strains PR281-7, PR338-8, PR339-3, PR340-8, and PR347-9 were obtained, and they could effectively resist phage infection. Meanwhile, they had good growth ability, did not contain pseudolysogenic strains, and were controllable. The resultant phage-resistant strains maintained the capabilities of producing recombinant proteins since no difference in mCherry red fluorescent protein expression was found in phage-resistant strains. Comparative genomics showed that PR281-7, PR338-8, PR339-3, and PR340-8 mutated in ecpE, nohD, nrdR, and livM genes, respectively. In this work, a strategy was successfully developed to obtain phage-resistant strains with excellent protein expression characteristics by Tn5 transposon mutation. This study provides a new reference to solve the phage contamination problem.
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Affiliation(s)
- Yinfeng Wang
- Food Safety Laboratory, College of Food Science and Engineering, Ocean University of China, 266003, Qingdao, People's Republic of China
| | - Guanhua Xuan
- Food Safety Laboratory, College of Food Science and Engineering, Ocean University of China, 266003, Qingdao, People's Republic of China
| | - Houqi Ning
- Food Safety Laboratory, College of Food Science and Engineering, Ocean University of China, 266003, Qingdao, People's Republic of China
| | - Jiuna Kong
- Food Safety Laboratory, College of Food Science and Engineering, Ocean University of China, 266003, Qingdao, People's Republic of China
| | - Hong Lin
- Food Safety Laboratory, College of Food Science and Engineering, Ocean University of China, 266003, Qingdao, People's Republic of China
| | - Jingxue Wang
- Food Safety Laboratory, College of Food Science and Engineering, Ocean University of China, 266003, Qingdao, People's Republic of China.
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2
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Brussowvirus SW13 requires a cell surface-associated polysaccharide to recognise its Streptococcus thermophilus host. Appl Environ Microbiol 2021; 88:e0172321. [PMID: 34669424 PMCID: PMC8752142 DOI: 10.1128/aem.01723-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Four bacteriophage-insensitive mutants (BIMs) of the dairy starter bacterium Streptococcus thermophilus UCCSt50 were isolated following challenge with Brussowvirus SW13. The BIMs displayed an altered sedimentation phenotype. Whole-genome sequencing and comparative genomic analysis of the BIMs uncovered mutations within a family 2 glycosyltransferase-encoding gene (orf06955UCCSt50) located within the variable region of the cell wall-associated rhamnose-glucose polymer (Rgp) biosynthesis locus (designated the rgp gene cluster here). Complementation of a representative BIM, S. thermophilus B1, with native orf06955UCCSt50 restored phage sensitivity comparable to that of the parent strain. Detailed bioinformatic analysis of the gene product of orf06955UCCSt50 identified it as a functional homolog of the Lactococcus lactispolysaccharide pellicle (PSP) initiator WpsA. Biochemical analysis of cell wall fractions of strains UCCSt50 and B1 determined that mutations within orf06955UCCSt50 result in the loss of the side chain decoration from the Rgp backbone structure. Furthermore, it was demonstrated that the intact Rgp structure incorporating the side chain structure is essential for phage binding through fluorescence labeling studies. Overall, this study confirms that the rgp gene cluster of S. thermophilus encodes the biosynthetic machinery for a cell surface-associated polysaccharide that is essential for binding and subsequent infection by Brussowviruses, thus enhancing our understanding of S. thermophilus phage-host dynamics. IMPORTANCEStreptococcus thermophilus is an important starter culture bacterium in global dairy fermentation processes, where it is used for the production of various cheeses and yogurt. Bacteriophage predation of the species can result in substandard product quality and, in rare cases, complete fermentation collapse. To mitigate these risks, it is necessary to understand the phage-host interaction process, which commences with the recognition of, and adsorption to, specific host-encoded cell surface receptors by bacteriophage(s). As new groups of S. thermophilus phages are being discovered, the importance of underpinning the genomic elements that specify the surface receptor(s) is apparent. Our research identifies a single gene that is critical for the biosynthesis of a saccharidic moiety required for phage adsorption to its S. thermophilus host. The acquired knowledge provides novel insights into phage-host interactions for this economically important starter species.
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3
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Hanemaaijer L, Kelleher P, Neve H, Franz CMAP, de Waal PP, van Peij NNME, van Sinderen D, Mahony J. Biodiversity of Phages Infecting the Dairy Bacterium Streptococcus thermophilus. Microorganisms 2021; 9:microorganisms9091822. [PMID: 34576718 PMCID: PMC8470116 DOI: 10.3390/microorganisms9091822] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 12/26/2022] Open
Abstract
Streptococcus thermophilus-infecting phages represent a major problem in the dairy fermentation industry, particularly in relation to thermophilic production systems. Consequently, numerous studies have been performed relating to the biodiversity of such phages in global dairy operations. In the current review, we provide an overview of the genetic and morphological diversity of these phages and highlight the source and extent of genetic mosaicism among phages infecting this species through comparative proteome analysis of the replication and morphogenesis modules of representative phages. The phylogeny of selected phage-encoded receptor binding proteins (RBPs) was assessed, indicating that in certain cases RBP-encoding genes have been acquired separately to the morphogenesis modules, thus highlighting the adaptability of these phages. This review further highlights the significant advances that have been made in defining emergent genetically diverse groups of these phages, while it additionally summarizes remaining knowledge gaps in this research area.
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Affiliation(s)
| | - Philip Kelleher
- School of Microbiology and APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland;
| | - Horst Neve
- Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Centre of Nutrition and Food, 24103 Kiel, Germany; (H.N.); (C.M.A.P.F.)
| | - Charles M. A. P. Franz
- Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Centre of Nutrition and Food, 24103 Kiel, Germany; (H.N.); (C.M.A.P.F.)
| | | | | | - Douwe van Sinderen
- School of Microbiology and APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland;
- Correspondence: (D.v.S.); (J.M.); Tel.: +353-20-4901365 (D.v.S.); +353-21-4902730 (J.M.)
| | - Jennifer Mahony
- School of Microbiology and APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland;
- Correspondence: (D.v.S.); (J.M.); Tel.: +353-20-4901365 (D.v.S.); +353-21-4902730 (J.M.)
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4
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Romero DA, Magill D, Millen A, Horvath P, Fremaux C. Dairy lactococcal and streptococcal phage-host interactions: an industrial perspective in an evolving phage landscape. FEMS Microbiol Rev 2021; 44:909-932. [PMID: 33016324 DOI: 10.1093/femsre/fuaa048] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 09/18/2020] [Indexed: 12/14/2022] Open
Abstract
Almost a century has elapsed since the discovery of bacteriophages (phages), and 85 years have passed since the emergence of evidence that phages can infect starter cultures, thereby impacting dairy fermentations. Soon afterward, research efforts were undertaken to investigate phage interactions regarding starter strains. Investigations into phage biology and morphology and phage-host relationships have been aimed at mitigating the negative impact phages have on the fermented dairy industry. From the viewpoint of a supplier of dairy starter cultures, this review examines the composition of an industrial phage collection, providing insight into the development of starter strains and cultures and the evolution of phages in the industry. Research advances in the diversity of phages and structural bases for phage-host recognition and an overview of the perpetual arms race between phage virulence and host defense are presented, with a perspective toward the development of improved phage-resistant starter culture systems.
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Affiliation(s)
- Dennis A Romero
- DuPont Nutrition and Biosciences, 3329 Agriculture Dr., Madison, WI 53716, USA
| | - Damian Magill
- DuPont Nutrition and Biosciences, CS 10010, Dangé-Saint-Romain 86220, France
| | - Anne Millen
- DuPont Nutrition and Biosciences, 3329 Agriculture Dr., Madison, WI 53716, USA
| | - Philippe Horvath
- DuPont Nutrition and Biosciences, CS 10010, Dangé-Saint-Romain 86220, France
| | - Christophe Fremaux
- DuPont Nutrition and Biosciences, CS 10010, Dangé-Saint-Romain 86220, France
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5
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Philippe C, Moineau S. The endless battle between phages and CRISPR-Cas systems in Streptococcus thermophilus. Biochem Cell Biol 2021; 99:397-402. [PMID: 33534660 DOI: 10.1139/bcb-2020-0593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
This review describes the contribution of basic research on phage-bacteria interactions to the understanding of CRISPR-Cas systems and their various applications. It focuses on the natural function of CRISPR-Cas systems as adaptive defense mechanisms against mobile genetic elements such as bacteriophage genomes and plasmids. Some of the advances in the characterization of the type II-A CRISPR-Cas system of Streptococcus thermophilus and Streptococcus pyogenes led to the development of the CRISPR-Cas9 genome-editing technology. We mostly discuss the 3 stages of the CRISPR-Cas system in S. thermophilus, namely the adaptation stage, which is unique to this resistance mechanism; the CRISPR RNA biogenesis; and the DNA-cutting activity in the interference stage to protect bacteria against phages. Finally, we look into applications of CRISPR-Cas in microbiology, including overcoming limitations in genome editing.
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Affiliation(s)
- Cécile Philippe
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec, QC G1V 0A6, Canada.,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec, QC G1V 0A6, Canada
| | - Sylvain Moineau
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec, QC G1V 0A6, Canada.,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec, QC G1V 0A6, Canada.,Félix d'Hérelle Reference Center for Bacterial Viruses, Université Laval, Québec, QC G1V 0A6, Canada
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6
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Lavelle K, Goulet A, McDonnell B, Spinelli S, van Sinderen D, Mahony J, Cambillau C. Revisiting the host adhesion determinants of Streptococcus thermophilus siphophages. Microb Biotechnol 2020; 13:1765-1779. [PMID: 32525270 PMCID: PMC7533335 DOI: 10.1111/1751-7915.13593] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/15/2020] [Accepted: 04/22/2020] [Indexed: 11/29/2022] Open
Abstract
Available 3D structures of bacteriophage modules combined with predictive bioinformatic algorithms enabled the identification of adhesion modules in 57 siphophages infecting Streptococcus thermophilus (St). We identified several carbohydrate-binding modules (CBMs) in so-called evolved distal tail (Dit) and tail-associated lysozyme (Tal) proteins of St phage baseplates. We examined the open reading frame (ORF) downstream of the Tal-encoding ORF and uncovered the presence of a putative p2-like receptor-binding protein (RBP). A 21 Å resolution electron microscopy structure of the baseplate of cos-phage STP1 revealed the presence of six elongated electron densities, surrounding the core of the baseplate, that harbour the p2-like RBPs at their tip. To verify the functionality of these modules, we expressed GFP- or mCherry-coupled Tal and putative RBP CBMs and observed by fluorescence microscopy that both modules bind to their corresponding St host, the putative RBP CBM with higher affinity than the Tal-associated one. The large number of CBM functional domains in St phages suggests that they play a contributory role in the infection process, a feature that we previously described in lactococcal phages and beyond, possibly representing a universal feature of the siphophage host-recognition apparatus.
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Affiliation(s)
| | - Adeline Goulet
- Architecture et Fonction des Macromolécules BiologiquesAix‐Marseille UniversitéCampus de LuminyMarseilleFrance
- Architecture et Fonction des Macromolécules BiologiquesCentre National de la Recherche Scientifique (CNRS)Campus de LuminyMarseilleFrance
| | | | - Silvia Spinelli
- Architecture et Fonction des Macromolécules BiologiquesAix‐Marseille UniversitéCampus de LuminyMarseilleFrance
- Architecture et Fonction des Macromolécules BiologiquesCentre National de la Recherche Scientifique (CNRS)Campus de LuminyMarseilleFrance
| | - Douwe van Sinderen
- School of MicrobiologyUniversity College CorkCorkIreland
- APC Microbiome IrelandUniversity College CorkCorkIreland
| | - Jennifer Mahony
- School of MicrobiologyUniversity College CorkCorkIreland
- APC Microbiome IrelandUniversity College CorkCorkIreland
| | - Christian Cambillau
- School of MicrobiologyUniversity College CorkCorkIreland
- Architecture et Fonction des Macromolécules BiologiquesAix‐Marseille UniversitéCampus de LuminyMarseilleFrance
- Architecture et Fonction des Macromolécules BiologiquesCentre National de la Recherche Scientifique (CNRS)Campus de LuminyMarseilleFrance
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7
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Novel Genus of Phages Infecting Streptococcus thermophilus: Genomic and Morphological Characterization. Appl Environ Microbiol 2020; 86:AEM.00227-20. [PMID: 32303549 DOI: 10.1128/aem.00227-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/13/2020] [Indexed: 12/26/2022] Open
Abstract
Streptococcus thermophilus is a lactic acid bacterium commonly used for the manufacture of yogurt and specialty cheeses. Virulent phages represent a major risk for milk fermentation processes worldwide, as they can inactivate the added starter bacterial cells, leading to low-quality fermented dairy products. To date, four genetically distinct groups of phages infecting S. thermophilus have been described. Here, we describe a fifth group. Phages P738 and D4446 are virulent siphophages that infect a few industrial strains of S. thermophilus The genomes of phages P738 and D4446 were sequenced and found to contain 34,037 and 33,656 bp as well as 48 and 46 open reading frames, respectively. Comparative genomic analyses revealed that the two phages are closely related to each other but display very limited similarities to other S. thermophilus phages. In fact, these two novel S. thermophilus phages share similarities with streptococcal phages of nondairy origin, suggesting that they emerged recently in the dairy environment.IMPORTANCE Despite decades of research and adapted antiphage strategies such as CRISPR-Cas systems, virulent phages are still a persistent risk for the milk fermentation industry worldwide, as they can cause manufacturing failures and alter product quality. Phages P738 and D4446 are novel virulent phages that infect the food-grade Gram-positive bacterial species Streptococcus thermophilus These two related viruses represent a fifth group of S. thermophilus phages, as they are significantly distinct from other known S. thermophilus phages. Both phages share similarities with phages infecting nondairy streptococci, suggesting their recent emergence and probable coexistence in dairy environments. These findings highlight the necessity of phage surveillance programs as the phage population evolves in response to the application of antiphage strategies.
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8
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McDonnell B, Hanemaaijer L, Bottacini F, Kelleher P, Lavelle K, Sadovskaya I, Vinogradov E, Ver Loren van Themaat E, Kouwen T, Mahony J, van Sinderen D. A cell wall-associated polysaccharide is required for bacteriophage adsorption to the Streptococcus thermophilus cell surface. Mol Microbiol 2020; 114:31-45. [PMID: 32073719 DOI: 10.1111/mmi.14494] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 02/17/2020] [Accepted: 02/17/2020] [Indexed: 11/29/2022]
Abstract
Streptococcus thermophilus strain ST64987 was exposed to a member of a recently discovered group of S. thermophilus phages (the 987 phage group), generating phage-insensitive mutants, which were then characterized phenotypically and genomically. Decreased phage adsorption was observed in selected bacteriophage-insensitive mutants, and was partnered with a sedimenting phenotype and increased cell chain length or aggregation. Whole genome sequencing of several bacteriophage-insensitive mutants identified mutations located in a gene cluster presumed to be responsible for cell wall polysaccharide production in this strain. Analysis of cell surface-associated glycans by methylation and NMR spectroscopy revealed a complex branched rhamno-polysaccharide in both ST64987 and phage-insensitive mutant BIM3. In addition, a second cell wall-associated polysaccharide of ST64987, composed of hexasaccharide branched repeating units containing galactose and glucose, was absent in the cell wall of mutant BIM3. Genetic complementation of three phage-resistant mutants was shown to restore the carbohydrate and phage resistance profiles of the wild-type strain, establishing the role of this gene cluster in cell wall polysaccharide production and phage adsorption and, thus, infection.
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Affiliation(s)
- Brian McDonnell
- School of Microbiology and APC Microbiome Ireland, University College Cork, Cork, Ireland
| | | | - Francesca Bottacini
- School of Microbiology and APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Philip Kelleher
- School of Microbiology and APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Katherine Lavelle
- School of Microbiology and APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Irina Sadovskaya
- Équipe BPA, Université du Littoral Côte d'Opale, Institut Régional Charles Violette EA 7394, USC Anses-ULCO, Boulogne-sur-Mer, France
| | - Evgeny Vinogradov
- Institute for Biological Sciences, National Research Council of Canada, Ottawa, ON, Canada
| | | | - Thijs Kouwen
- DSM Biotechnology Center, Delft, the Netherlands
| | - Jennifer Mahony
- School of Microbiology and APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Douwe van Sinderen
- School of Microbiology and APC Microbiome Ireland, University College Cork, Cork, Ireland
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9
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Szymczak P, Rau MH, Monteiro JM, Pinho MG, Filipe SR, Vogensen FK, Zeidan AA, Janzen T. A comparative genomics approach for identifying host-range determinants in Streptococcus thermophilus bacteriophages. Sci Rep 2019; 9:7991. [PMID: 31142793 PMCID: PMC6541646 DOI: 10.1038/s41598-019-44481-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 05/07/2019] [Indexed: 12/17/2022] Open
Abstract
Comparative genomics has proven useful in exploring the biodiversity of phages and understanding phage-host interactions. This knowledge is particularly useful for phages infecting Streptococcus thermophilus, as they constitute a constant threat during dairy fermentations. Here, we explore the genetic diversity of S. thermophilus phages to identify genetic determinants with a signature for host specificity, which could be linked to the bacterial receptor genotype. A comparative genomic analysis was performed on 142 S. thermophilus phage genomes, 55 of which were sequenced in this study. Effectively, 94 phages were assigned to the group cos (DT1), 36 to the group pac (O1205), six to the group 5093, and six to the group 987. The core genome-based phylogeny of phages from the two dominating groups and their receptor binding protein (RBP) phylogeny corresponded to the phage host-range. A role of RBP in host recognition was confirmed by constructing a fluorescent derivative of the RBP of phage CHPC951, followed by studying the binding of the protein to the host strain. Furthermore, the RBP phylogeny of the cos group was found to correlate with the host genotype of the exocellular polysaccharide-encoding operon. These findings provide novel insights towards developing strategies to combat phage infections in dairies.
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Affiliation(s)
- Paula Szymczak
- Bacterial Physiology, R&D, Chr. Hansen A/S, 2970, Hørsholm, Denmark
- Department of Food Science, University of Copenhagen, 1958, Frederiksberg, Denmark
| | - Martin Holm Rau
- Bacterial Physiology, R&D, Chr. Hansen A/S, 2970, Hørsholm, Denmark
| | - João M Monteiro
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
| | - Mariana G Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
| | - Sérgio Raposo Filipe
- UCIBIO-REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
- Laboratory of Bacterial Cell Surfaces and Pathogenesis, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
| | - Finn Kvist Vogensen
- Department of Food Science, University of Copenhagen, 1958, Frederiksberg, Denmark
| | - Ahmad A Zeidan
- Bacterial Physiology, R&D, Chr. Hansen A/S, 2970, Hørsholm, Denmark
| | - Thomas Janzen
- Bacterial Physiology, R&D, Chr. Hansen A/S, 2970, Hørsholm, Denmark.
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10
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11
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Biodiversity of Streptococcus thermophilus Phages in Global Dairy Fermentations. Viruses 2018; 10:v10100577. [PMID: 30360457 PMCID: PMC6213268 DOI: 10.3390/v10100577] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 12/26/2022] Open
Abstract
Streptococcus thermophilus strains are among the most widely employed starter cultures in dairy fermentations, second only to those of Lactococcus lactis. The extensive application of this species provides considerable opportunity for the proliferation of its infecting (bacterio)phages. Until recently, dairy streptococcal phages were classified into two groups (cos and pac groups), while more recently, two additional groups have been identified (5093 and 987 groups). This highlights the requirement for consistent monitoring of phage populations in the industry. Here, we report a survey of 35 samples of whey derived from 27 dairy fermentation facilities in ten countries against a panel of S. thermophilus strains. This culminated in the identification of 172 plaque isolates, which were characterized by multiplex PCR, restriction fragment length polymorphism analysis, and host range profiling. Based on this characterisation, 39 distinct isolates representing all four phage groups were selected for genome sequencing. Genetic diversity was observed among the cos isolates and correlations between receptor binding protein phylogeny and host range were also clear within this phage group. The 987 phages isolated within this study shared high levels of sequence similarity, yet displayed reduced levels of similarity to those identified in previous studies, indicating that they are subject to ongoing genetic diversification.
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12
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Abstract
Phages of Streptococcus thermophilus present a major threat to the production of many fermented dairy products. To date, only a few studies have assessed the biodiversity of S. thermophilus phages in dairy fermentations. In order to develop strategies to limit phage predation in this important industrial environment, it is imperative that such studies are undertaken and that phage-host interactions of this species are better defined. The present study investigated the biodiversity and evolution of phages within an Irish dairy fermentation facility over an 11-year period. This resulted in the isolation of 17 genetically distinct phages, all of which belong to the so-called cos group. The evolution of phages within the factory appears to be influenced by phages from other dairy plants introduced into the factory for whey protein powder production. Modular exchange, primarily within the regions encoding lysogeny and replication functions, was the major observation among the phages isolated between 2006 and 2016. Furthermore, the genotype of the first isolate in 2006 was observed continuously across the following decade, highlighting the ability of these phages to prevail in the factory setting for extended periods of time. The proteins responsible for host recognition were analyzed, and carbohydrate-binding domains (CBDs) were identified in the distal tail (Dit), the baseplate proteins, and the Tail-associated lysin (Tal) variable regions (VR1 and VR2) of many isolates. This supports the notion that S. thermophilus phages recognize a carbohydrate receptor on the cell surface of their host.IMPORTANCE Dairy fermentations are consistently threatened by the presence of bacterial viruses (bacteriophages or phages), which may lead to a reduction in acidification rates or even complete loss of the fermentate. These phages may persist in factories for long periods of time. The objective of the current study was to monitor the progression of phages infecting the dairy bacterium Streptococcus thermophilus over a period of 11 years in an Irish dairy plant so as to understand how these phages evolve. A focused analysis of the genomic region that encodes host recognition functions highlighted that the associated proteins harbor a variety of carbohydrate-binding domains, which corroborates the notion that phages of S. thermophilus recognize carbohydrate receptors at the initial stages of the phage cycle.
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13
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Mahony J, Cambillau C, van Sinderen D. Host recognition by lactic acid bacterial phages. FEMS Microbiol Rev 2018; 41:S16-S26. [PMID: 28830088 DOI: 10.1093/femsre/fux019] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 04/05/2017] [Indexed: 02/07/2023] Open
Abstract
Bacteriophage infection of lactic acid bacteria (LAB) is one of the most significant causes of inconsistencies in the manufacture of fermented foods, affecting production schedules and organoleptic properties of the final product. Consequently, LAB phages, and particularly those infecting Lactococcus lactis, have been the focus of intensive research efforts. During the past decade, multidisciplinary scientific approaches have uncovered molecular details on the exquisite process of how a lactococcal phage recognises and binds to its host. Such approaches have incorporated genomic/molecular analyses and their partnership with phage structural analysis and host cell wall biochemical studies are discussed in this review, which will also provide our views on future directions of this research field.
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Affiliation(s)
- Jennifer Mahony
- School of Microbiology, University College Cork, Cork T12 YT20, Ireland.,APC Microbiome Institute, University College Cork, Cork T12 YT20, Ireland
| | - Christian Cambillau
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, Marseille, 13288 Marseille, France.,Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique (CNRS), Campus de Luminy, Marseille, 13288 Marseille, France
| | - Douwe van Sinderen
- School of Microbiology, University College Cork, Cork T12 YT20, Ireland.,APC Microbiome Institute, University College Cork, Cork T12 YT20, Ireland
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14
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McDonnell B, Mahony J, Hanemaaijer L, Kouwen TRHM, van Sinderen D. Generation of Bacteriophage-Insensitive Mutants of Streptococcus thermophilus via an Antisense RNA CRISPR-Cas Silencing Approach. Appl Environ Microbiol 2018; 84:e01733-17. [PMID: 29180373 PMCID: PMC5795082 DOI: 10.1128/aem.01733-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 11/20/2017] [Indexed: 12/26/2022] Open
Abstract
Predation of starter lactic acid bacteria such as Streptococcus thermophilus by bacteriophages is a persistent and costly problem in the dairy industry. CRISPR-mediated bacteriophage insensitive mutants (BIMs), while straightforward to generate and verify, can quickly be overcome by mutant phages. The aim of this study was to develop a tool allowing the generation of derivatives of commercial S. thermophilus strains which are resistant to phage attack through a non-CRISPR-mediated mechanism, with the objective of generating BIMs exhibiting stable resistance against a range of isolated lytic S. thermophilus phages. To achieve this, standard BIM generation was complemented by the use of the wild-type (WT) strain which had been transformed with an antisense mRNA-generating plasmid (targeting a crucial CRISPR-associated [cas] gene) in order to facilitate the generation of non-CRISPR-mediated BIMs. Phage sensitivity assays suggest that non-CRISPR-mediated BIMs exhibit some advantages compared to CRISPR-mediated BIMs derived from the same strain.IMPORTANCE The outlined approach reveals the presence of a powerful host-imposed barrier for phage infection in S. thermophilus Considering the detrimental economic consequences of phage infection in the dairy processing environment, the developed methodology has widespread applications, particularly where other methods may not be practical or effective in obtaining robust, phage-tolerant S. thermophilus starter strains.
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Affiliation(s)
- Brian McDonnell
- School of Microbiology & APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Jennifer Mahony
- School of Microbiology & APC Microbiome Institute, University College Cork, Cork, Ireland
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | | | | | - Douwe van Sinderen
- School of Microbiology & APC Microbiome Institute, University College Cork, Cork, Ireland
- APC Microbiome Institute, University College Cork, Cork, Ireland
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15
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McDonnell B, Mahony J, Hanemaaijer L, Neve H, Noben JP, Lugli GA, Ventura M, Kouwen TR, van Sinderen D. Global Survey and Genome Exploration of Bacteriophages Infecting the Lactic Acid Bacterium Streptococcus thermophilus. Front Microbiol 2017; 8:1754. [PMID: 28955321 PMCID: PMC5601072 DOI: 10.3389/fmicb.2017.01754] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 08/29/2017] [Indexed: 01/31/2023] Open
Abstract
Despite the persistent and costly problem caused by (bacterio)phage predation of Streptococcus thermophilus in dairy plants, DNA sequence information relating to these phages remains limited. Genome sequencing is necessary to better understand the diversity and proliferative strategies of virulent phages. In this report, whole genome sequences of 40 distinct bacteriophages infecting S. thermophilus were analyzed for general characteristics, genomic structure and novel features. The bacteriophage genomes display a high degree of conservation within defined groupings, particularly across the structural modules. Supporting this observation, four novel members of a recently discovered third group of S. thermophilus phages (termed the 5093 group) were found to be conserved relative to both phage 5093 and to each other. Replication modules of S. thermophilus phages generally fall within two main groups, while such phage genomes typically encode one putative transcriptional regulator. Such features are indicative of widespread functional synteny across genetically distinct phage groups. Phage genomes also display nucleotide divergence between groups, and between individual phages of the same group (within replication modules and at the 3′ end of the lysis module)—through various insertions and/or deletions. A previously described multiplex PCR phage detection system was updated to reflect current knowledge on S. thermophilus phages. Furthermore, the structural protein complement as well as the antireceptor (responsible for the initial attachment of the phage to the host cell) of a representative of the 5093 group was defined. Our data more than triples the currently available genomic information on S. thermophilus phages, being of significant value to the dairy industry, where genetic knowledge of lytic phages is crucial for phage detection and monitoring purposes. In particular, the updated PCR detection methodology for S. thermophilus phages is highly useful in monitoring particular phage group(s) present in a given whey sample. Studies of this nature therefore not only provide information on the prevalence and associated threat of known S. thermophilus phages, but may also uncover newly emerging and genomically distinct phages infecting this dairy starter bacterium.
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Affiliation(s)
- Brian McDonnell
- School of Microbiology, College of Science, Engineering and Food Science, University College CorkCork, Ireland
| | - Jennifer Mahony
- School of Microbiology, College of Science, Engineering and Food Science, University College CorkCork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland
| | | | - Horst Neve
- Department of Microbiology and Biotechnology, Max Rubner-InstitutKiel, Germany
| | - Jean-Paul Noben
- Biomedical Research Institute, Hasselt UniversityDiepenbeek, Belgium
| | - Gabriele A Lugli
- Laboratory of Probiogenomics, Department of Life Sciences, University of ParmaParma, Italy
| | - Marco Ventura
- Laboratory of Probiogenomics, Department of Life Sciences, University of ParmaParma, Italy
| | | | - Douwe van Sinderen
- School of Microbiology, College of Science, Engineering and Food Science, University College CorkCork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland
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16
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Novel Variants of Streptococcus thermophilus Bacteriophages Are Indicative of Genetic Recombination among Phages from Different Bacterial Species. Appl Environ Microbiol 2017; 83:AEM.02748-16. [PMID: 28039135 PMCID: PMC5311409 DOI: 10.1128/aem.02748-16] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 12/12/2016] [Indexed: 12/03/2022] Open
Abstract
Bacteriophages are the main cause of fermentation failures in dairy plants. The majority of Streptococcus thermophilus phages can be divided into either cos- or pac-type phages and are additionally characterized by examining the V2 region of their antireceptors. We screened a large number of S. thermophilus phages from the Chr. Hansen A/S collection, using PCR specific for the cos- or pac-type phages, as well as for the V2 antireceptor region. Three phages did not produce positive results with the assays. Analysis of phage morphologies indicated that two of these phages, CHPC577 and CHPC926, had shorter tails than the traditional S. thermophilus phages. The third phage, CHPC1151, had a tail size similar to those of the cos- or pac-type phages, but it displayed a different baseplate structure. Sequencing analysis revealed the genetic similarity of CHPC577 and CHPC926 with a subgroup of Lactococcus lactis P335 phages. Phage CHPC1151 was closely related to the atypical S. thermophilus phage 5093, homologous with a nondairy streptococcal prophage. By testing adsorption of the related streptococcal and lactococcal phages to the surface of S. thermophilus and L. lactis strains, we revealed the possibility of cross-interactions. Our data indicated that the use of S. thermophilus together with L. lactis, extensively applied for dairy fermentations, triggered the recombination between phages infecting different bacterial species. A notable diversity among S. thermophilus phage populations requires that a new classification of the group be proposed. IMPORTANCEStreptococcus thermophilus is a component of thermophilic starter cultures commonly used for cheese and yogurt production. Characterizing streptococcal phages, understanding their genetic relationships, and studying their interactions with various hosts are the necessary steps for preventing and controlling phage attacks that occur during dairy fermentations.
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17
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The Presence of Two Receptor-Binding Proteins Contributes to the Wide Host Range of Staphylococcal Twort-Like Phages. Appl Environ Microbiol 2016; 82:5763-74. [PMID: 27422842 DOI: 10.1128/aem.01385-16] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 07/13/2016] [Indexed: 12/31/2022] Open
Abstract
UNLABELLED Thanks to their wide host range and virulence, staphylococcal bacteriophages (phages) belonging to the genus Twortlikevirus (staphylococcal Twort-like phages) are regarded as ideal candidates for clinical application for Staphylococcus aureus infections due to the emergence of antibiotic-resistant bacteria of this species. To increase the usability of these phages, it is necessary to understand the mechanism underlying host recognition, especially the receptor-binding proteins (RBPs) that determine host range. In this study, we found that the staphylococcal Twort-like phage ΦSA012 possesses at least two RBPs. Genomic analysis of five mutant phages of ΦSA012 revealed point mutations in orf103, in a region unique to staphylococcal Twort-like phages. Phages harboring mutated ORF103 could not infect S. aureus strains in which wall teichoic acids (WTAs) are glycosylated with α-N-acetylglucosamine (α-GlcNAc). A polyclonal antibody against ORF103 also inhibited infection by ΦSA012 in the presence of α-GlcNAc, suggesting that ORF103 binds to α-GlcNAc. In contrast, a polyclonal antibody against ORF105, a short tail fiber component previously shown to be an RBP, inhibited phage infection irrespective of the presence of α-GlcNAc. Immunoelectron microscopy indicated that ORF103 is a tail fiber component localized at the bottom of the baseplate. From these results, we conclude that ORF103 binds α-GlcNAc in WTAs, whereas ORF105, the primary RBP, is likely to bind the WTA backbone. These findings provide insight into the infection mechanism of staphylococcal Twort-like phages. IMPORTANCE Staphylococcus phages belonging to the genus Twortlikevirus (called staphylococcal Twort-like phages) are considered promising agents for control of Staphylococcus aureus due to their wide host range and highly lytic capabilities. Although staphylococcal Twort-like phages have been studied widely for therapeutic purposes, the host recognition process of staphylococcal Twort-like phages remains unclear. This work provides new findings about the mechanisms of host recognition of the staphylococcal Twort-like phage ΦSA012. The details of the host recognition mechanism of ΦSA012 will allow us to analyze the mechanisms of infection and expand the utility of staphylococcal Twort-like phages for the control of S. aureus.
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18
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Mahony J, McDonnell B, Casey E, van Sinderen D. Phage-Host Interactions of Cheese-Making Lactic Acid Bacteria. Annu Rev Food Sci Technol 2016; 7:267-85. [PMID: 26735798 DOI: 10.1146/annurev-food-041715-033322] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cheese production is a global biotechnological practice that is reliant on robust and technologically appropriate starter and adjunct starter cultures to acidify the milk and impart particular flavor and textural properties to specific cheeses. To this end, lactic acid bacteria, including Lactococcus lactis, Streptococcus thermophilus, and Lactobacillus and Leuconostoc spp., are routinely employed. However, these bacteria are susceptible to infection by (bacterio)phages. Over the past decade in particular, significant advances have been achieved in defining the receptor molecules presented by lactococcal host bacteria and in the structural analysis of corresponding phage-encoded receptor-binding proteins. These lactococcal model systems are expanding toward understanding phage-host interactions of other LAB species. Ultimately, such scientific efforts will uncover the mechanistic (dis)similarities among these phages and define how these phages recognize and infect their hosts. This review presents the current status of the LAB-phage interactome, highlighting the most recent and significant developments in this active research field.
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Affiliation(s)
| | | | | | - Douwe van Sinderen
- School of Microbiology;,APC Microbiome Institute, University College Cork, Western Road, Cork, Ireland;
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19
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Treatment of Highly Virulent Extraintestinal Pathogenic Escherichia coli Pneumonia With Bacteriophages*. Crit Care Med 2015; 43:e190-8. [DOI: 10.1097/ccm.0000000000000968] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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20
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Complete Genome Sequence of Streptococcus thermophilus SMQ-301, a Model Strain for Phage-Host Interactions. GENOME ANNOUNCEMENTS 2015; 3:3/3/e00480-15. [PMID: 25999573 PMCID: PMC4440953 DOI: 10.1128/genomea.00480-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Streptococcus thermophilus is used by the dairy industry to manufacture yogurt and several cheeses. Using PacBio and Illumina platforms, we sequenced the genome of S. thermophilus SMQ-301, the host of several virulent phages. The genome is composed of 1,861,792 bp and contains 2,037 genes, 67 tRNAs, and 18 rRNAs.
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21
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Edlund A, Santiago-Rodriguez TM, Boehm TK, Pride DT. Bacteriophage and their potential roles in the human oral cavity. J Oral Microbiol 2015; 7:27423. [PMID: 25861745 PMCID: PMC4393417 DOI: 10.3402/jom.v7.27423] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/11/2015] [Accepted: 03/13/2015] [Indexed: 12/26/2022] Open
Abstract
The human oral cavity provides the perfect portal of entry for viruses and bacteria in the environment to access new hosts. Hence, the oral cavity is one of the most densely populated habitats of the human body containing some 6 billion bacteria and potentially 35 times that many viruses. The role of these viral communities remains unclear; however, many are bacteriophage that may have active roles in shaping the ecology of oral bacterial communities. Other implications for the presence of such vast oral phage communities include accelerating the molecular diversity of their bacterial hosts as both host and phage mutate to gain evolutionary advantages. Additional roles include the acquisitions of new gene functions through lysogenic conversions that may provide selective advantages to host bacteria in response to antibiotics or other types of disturbances, and protection of the human host from invading pathogens by binding to and preventing pathogens from crossing oral mucosal barriers. Recent evidence suggests that phage may be more involved in periodontal diseases than were previously thought, as their compositions in the subgingival crevice in moderate to severe periodontitis are known to be significantly altered. However, it is unclear to what extent they contribute to dysbiosis or the transition of the microbial community into a state promoting oral disease. Bacteriophage communities are distinct in saliva compared to sub- and supragingival areas, suggesting that different oral biogeographic niches have unique phage ecology shaping their bacterial biota. In this review, we summarize what is known about phage communities in the oral cavity, the possible contributions of phage in shaping oral bacterial ecology, and the risks to public health oral phage may pose through their potential to spread antibiotic resistance gene functions to close contacts.
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Affiliation(s)
- Anna Edlund
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, CA, USA.,School of Dentistry, University of California, Los Angeles, CA, USA
| | | | - Tobias K Boehm
- Western University College of Dental Medicine, Pomona, CA, USA
| | - David T Pride
- Department of Pathology, University of California, San Diego, CA, USA.,Department of Medicine, University of California, San Diego, CA, USA;
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22
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Lactococcal 949 group phages recognize a carbohydrate receptor on the host cell surface. Appl Environ Microbiol 2015; 81:3299-305. [PMID: 25746988 DOI: 10.1128/aem.00143-15] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Accepted: 02/25/2015] [Indexed: 12/27/2022] Open
Abstract
Lactococcal bacteriophages represent one of the leading causes of dairy fermentation failure and product inconsistencies. A new member of the lactococcal 949 phage group, named WRP3, was isolated from cheese whey from a Sicilian factory in 2011. The genome sequence of this phage was determined, and it constitutes the largest lactococcal phage genome currently known, at 130,008 bp. Detailed bioinformatic analysis of the genomic region encoding the presumed initiator complex and baseplate of WRP3 has aided in the functional assignment of several open reading frames (ORFs), particularly that for the receptor binding protein required for host recognition. Furthermore, we demonstrate that the 949 phages target cell wall phospho-polysaccharides as their receptors, accounting for the specificity of the interactions of these phages with their lactococcal hosts. Such information may ultimately aid in the identification of strains/strain blends that do not present the necessary saccharidic target for infection by these problematic phages.
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23
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Exposing the secrets of two well-known Lactobacillus casei phages, J-1 and PL-1, by genomic and structural analysis. Appl Environ Microbiol 2014; 80:7107-21. [PMID: 25217012 DOI: 10.1128/aem.02771-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacteriophage J-1 was isolated in 1965 from an abnormal fermentation of Yakult using Lactobacillus casei strain Shirota, and a related phage, PL-1, was subsequently recovered from a strain resistant to J-1. Complete genome sequencing shows that J-1 and PL-1 are almost identical, but PL-1 has a deletion of 1.9 kbp relative to J-1, resulting in the loss of four predicted gene products involved in immunity regulation. The structural proteins were identified by mass spectrometry analysis. Similarly to phage A2, two capsid proteins are generated by a translational frameshift and undergo proteolytic processing. The structure of gene product 16 (gp16), a putative tail protein, was modeled based on the crystal structure of baseplate distal tail proteins (Dit) that form the baseplate hub in other Siphoviridae. However, two regions of the C terminus of gp16 could not be modeled using this template. The first region accounts for the differences between J-1 and PL-1 gp16 and showed sequence similarity to carbohydrate-binding modules (CBMs). J-1 and PL-1 GFP-gp16 fusions bind specifically to Lactobacillus casei/paracasei cells, and the addition of l-rhamnose inhibits binding. J-1 gp16 exhibited a higher affinity than PL-1 gp16 for cell walls of L. casei ATCC 27139 in phage adsorption inhibition assays, in agreement with differential adsorption kinetics observed for both phages in this strain. The data presented here provide insights into how Lactobacillus phages interact with their hosts at the first steps of infection.
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24
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Chirico D, Gorla A, Verga V, Pedersen PD, Polgatti E, Cava A, Dal Bello F. Bacteriophage-insensitive mutants for high quality Crescenza manufacture. Front Microbiol 2014; 5:201. [PMID: 24834065 PMCID: PMC4018529 DOI: 10.3389/fmicb.2014.00201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 04/16/2014] [Indexed: 12/13/2022] Open
Abstract
Streptococcus thermophilus is a thermophilic lactic acid bacterium used as starter culture for the manufacture of fermented dairy products. For the production of Crescenza and other soft cheeses, Sacco has developed and provides dairies with three different defined blends of S. thermophilus strains. Each blend contains two different S. thermophilus strains. The strains were selected based on their unique technological properties as well as different phage profiles. Analysis of 133 whey samples collected in 2009–2010 from Italian dairies showed a high prevalence (about 50%) of bacteriophage attacks on the blend ST020. More specifically, the strain S. thermophilus ST1A was found to be the preferred target of the bacteriophages. A bacteriophage insensitive mutant (BIM5) of the phage-sensitive strain ST1A was successfully developed and used to substitute strain ST1A in the Crescenza starter culture ST020. The strain BIM5 showed identical technological and industrial traits as those of the phage-sensitive strain ST1A. The improved resistance of the modified Crescenza starter culture ST020R was confirmed at Italian dairies, and its effectiveness monitored on 122 whey samples collected in 2011–2012. Compared to the previous values (2009–2010), the use of the phage-hardened blend ST020R allowed reducing of frequency of phage attacks from about 50 to less than 5% of the whey samples investigated.
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Affiliation(s)
- Donatella Chirico
- Clerici-Sacco Group, Caglificio Clerici S.p.A. and Sacco S.r.l., Cadorago Italy
| | - Arianna Gorla
- Clerici-Sacco Group, Caglificio Clerici S.p.A. and Sacco S.r.l., Cadorago Italy
| | - Viola Verga
- Clerici-Sacco Group, Caglificio Clerici S.p.A. and Sacco S.r.l., Cadorago Italy
| | - Per D Pedersen
- Clerici-Sacco Group, Caglificio Clerici S.p.A. and Sacco S.r.l., Cadorago Italy
| | - Eliseo Polgatti
- Clerici-Sacco Group, Caglificio Clerici S.p.A. and Sacco S.r.l., Cadorago Italy
| | - Antonio Cava
- Clerici-Sacco Group, Caglificio Clerici S.p.A. and Sacco S.r.l., Cadorago Italy
| | - Fabio Dal Bello
- Clerici-Sacco Group, Caglificio Clerici S.p.A. and Sacco S.r.l., Cadorago Italy
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25
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Klumpp J, Fouts DE, Sozhamannan S. Bacteriophage functional genomics and its role in bacterial pathogen detection. Brief Funct Genomics 2013; 12:354-65. [DOI: 10.1093/bfgp/elt009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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26
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Identification of the receptor-binding protein in lytic Leuconostoc pseudomesenteroides bacteriophages. Appl Environ Microbiol 2013; 79:3311-4. [PMID: 23503306 DOI: 10.1128/aem.00012-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two phages, P793 and ΦLN04, sharing 80.1% nucleotide sequence identity but having different strains of Leuconostoc pseudomesenteroides as hosts, were selected for identification of the host determinant gene. Construction of chimeric phages leading to the expected switch in host range identified the host determinant genes as ORF21P793/ORF23ΦLN04. The genes are located in the tail structural module and have low sequence similarity at the distal end.
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27
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Mahony J, Ainsworth S, Stockdale S, van Sinderen D. Phages of lactic acid bacteria: the role of genetics in understanding phage-host interactions and their co-evolutionary processes. Virology 2012; 434:143-50. [PMID: 23089252 DOI: 10.1016/j.virol.2012.10.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 09/12/2012] [Accepted: 10/01/2012] [Indexed: 12/26/2022]
Abstract
Dairy fermentations are among the oldest food processing applications, aimed at preservation and shelf-life extension through the use of lactic acid bacteria (LAB) starter cultures, in particular strains of Lactococcus lactis, Streptococcus thermophilus, Lactobacillus spp. and Leuconostoc spp. Traditionally this was performed by continuous passaging of undefined cultures from a finished fermentation to initiate the next fermentation. More recently, consumer demands on consistent and desired flavours and textures of dairy products have led to a more defined approach to such processes. Dairy (starter) companies have responded to the need to define the nature and complexity of the starter culture mixes, and dairy fermentations are now frequently based on defined starter cultures of low complexity, where each starter component imparts specific technological properties that are desirable to the product. Both mixed and defined starter culture approaches create the perfect environment for the proliferation of (bacterio)phages capable of infecting these LAB. The repeated use of the same starter cultures in a single plant, coupled to the drive towards higher and consistent production levels, increases the risk and negative impact of phage infection. In this review we will discuss recent advances in tracking the adaptation of phages to the dairy industry, the advances in understanding LAB phage-host interactions, including evolutionary and genomic aspects.
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Affiliation(s)
- Jennifer Mahony
- Department of Microbiology, University College Cork, Western Road, Cork, Ireland.
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28
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Abstract
M102AD is the new designation for a Streptococcus mutans phage described in 1993 as phage M102. This change was necessitated by the genome analysis of another S. mutans phage named M102, which revealed differences from the genome sequence reported here. Additional host range analyses confirmed that S. mutans phage M102AD infects only a few serotype c strains. Phage M102AD adsorbed very slowly to its host, and it cannot adsorb to serotype e and f strains of S. mutans. M102AD adsorption was blocked by c-specific antiserum. Phage M102AD also adsorbed equally well to heat-treated and trypsin-treated cells, suggesting carbohydrate receptors. Saliva and polysaccharide production did not inhibit plaque formation. The genome of this siphophage consisted of a linear, double-stranded, 30,664-bp DNA molecule, with a GC content of 39.6%. Analysis of the genome extremities indicated the presence of a 3'-overhang cos site that was 11 nucleotides long. Bioinformatic analyses identified 40 open reading frames, all in the same orientation. No lysogeny-related genes were found, indicating that phage M102AD is strictly virulent. No obvious virulence factor gene candidates were found. Twelve proteins were identified in the virion structure by mass spectrometry. Comparative genomic analysis revealed a close relationship between S. mutans phages M102AD and M102 as well as with Streptococcus thermophilus phages. This study also highlights the importance of conducting research with biological materials obtained from recognized microbial collections.
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29
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Deveau H, Garneau JE, Moineau S. CRISPR/Cas system and its role in phage-bacteria interactions. Annu Rev Microbiol 2010; 64:475-93. [PMID: 20528693 DOI: 10.1146/annurev.micro.112408.134123] [Citation(s) in RCA: 404] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPRs) along with Cas proteins is a widespread system across bacteria and archaea that causes interference against foreign nucleic acids. The CRISPR/Cas system acts in at least two general stages: the adaptation stage, where the cell acquires new spacer sequences derived from foreign DNA, and the interference stage, which uses the recently acquired spacers to target and cleave invasive nucleic acid. The CRISPR/Cas system participates in a constant evolutionary battle between phages and bacteria through addition or deletion of spacers in host cells and mutations or deletion in phage genomes. This review describes the recent progress made in this fast-expanding field.
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Affiliation(s)
- Hélène Deveau
- Département de Biochimie, Microbiologie et Bio-informatique, Faculté des Sciences et de Génie, Groupe de Recherche en Ecologie Buccale, Université Laval, Quebec City, Quebec, G1V 0A6, Canada.
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30
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31
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Zinno P, Janzen T, Bennedsen M, Ercolini D, Mauriello G. Characterization of Streptococcus thermophilus lytic bacteriophages from mozzarella cheese plants. Int J Food Microbiol 2009; 138:137-44. [PMID: 20060612 DOI: 10.1016/j.ijfoodmicro.2009.12.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 12/02/2009] [Accepted: 12/05/2009] [Indexed: 11/17/2022]
Abstract
Phage infection still represents the main cause of fermentation failure during the mozzarella cheese manufacturing, where Streptococcus thermophilus is widely employed as starter culture. Thereby, the success of commercial lactic starter cultures is closely related to the use of strains with low susceptibility to phage attack. The characterization of lytic S. thermophilus bacteriophages is an important step for the selection and use of starter cultures. The aim of this study was to characterize 26 bacteriophages isolated from mozzarella cheese plants in terms of their host range, DNA restriction profile, DNA packaging mechanism, and the variable region VR2 of the antireceptor gene. The DNA restriction analysis was carried out by using the restriction enzymes EcoRV, PstI, and HindIII. The bacteriophages were distinguished into two main groups of S. thermophilus phages (cos- and pac-type) using a multiplex PCR method based on the amplification of conserved regions in the genes coding for the major structural proteins. All the phages belonged to the cos-type group except one, phage 1042, which gave a PCR fragment distinctive of pac-type group. Furthermore, DNA sequencing of the variable region VR2 of the antireceptor gene allowed to classify the phages and examine the correlation between typing profile and host range. Finally, bacterial strains used in this study were investigated for the presence of temperate phages by induction with mitomycin C and only S. thermophilus CHCC2070 was shown to be lysogenic.
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Affiliation(s)
- P Zinno
- Dipartimento di Scienza degli Alimenti, Università degli Studi di Napoli Federico II, Portici, Italy
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Streptococcus thermophilus phage monitoring in a cheese factory: Phage characteristics and starter sensitivity. Int Dairy J 2009. [DOI: 10.1016/j.idairyj.2009.02.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ahn SI, Azzouny RA, Huyen TTT, Kwak HS. The Characteristics, Detection and Control of Bacteriophage in Fermented Dairy Products. Korean J Food Sci Anim Resour 2009. [DOI: 10.5851/kosfa.2009.29.1.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Plasmid transfer via transduction from Streptococcus thermophilus to Lactococcus lactis. J Bacteriol 2008; 190:3083-7. [PMID: 18263725 DOI: 10.1128/jb.01448-07] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Using Streptococcus thermophilus phages, plasmid transduction in Lactococcus lactis was demonstrated. The transduction frequencies were 4 orders of magnitude lower in L. lactis than in S. thermophilus. These results are the first evidence that there is phage-mediated direct transfer of DNA from S. thermophilus to L. lactis. The implications of these results for phage evolution are discussed.
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Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) and their associated genes are linked to a mechanism of acquired resistance against bacteriophages. Bacteria can integrate short stretches of phage-derived sequences (spacers) within CRISPR loci to become phage resistant. In this study, we further characterized the efficiency of CRISPR1 as a phage resistance mechanism in Streptococcus thermophilus. First, we show that CRISPR1 is distinct from previously known phage defense systems and is effective against the two main groups of S. thermophilus phages. Analyses of 30 bacteriophage-insensitive mutants of S. thermophilus indicate that the addition of one new spacer in CRISPR1 is the most frequent outcome of a phage challenge and that the iterative addition of spacers increases the overall phage resistance of the host. The added new spacers have a size of between 29 to 31 nucleotides, with 30 being by far the most frequent. Comparative analysis of 39 newly acquired spacers with the complete genomic sequences of the wild-type phages 2972, 858, and DT1 demonstrated that the newly added spacer must be identical to a region (named proto-spacer) in the phage genome to confer a phage resistance phenotype. Moreover, we found a CRISPR1-specific sequence (NNAGAAW) located downstream of the proto-spacer region that is important for the phage resistance phenotype. Finally, we show through the analyses of 20 mutant phages that virulent phages are rapidly evolving through single nucleotide mutations as well as deletions, in response to CRISPR1.
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Kašpárek P, Pantůček R, Kahánková J, Růžičková V, Doškař J. Genome rearrangements in host-range mutants of the polyvalent staphylococcal bacteriophage 812. Folia Microbiol (Praha) 2007; 52:331-8. [DOI: 10.1007/bf02932087] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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