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Mehmood Khan F, Manohar P, Singh Gondil V, Mehra N, Kayode Oyejobi G, Odiwuor N, Ahmad T, Huang G. The applications of animal models in phage therapy: An update. Hum Vaccin Immunother 2023; 19:2175519. [PMID: 36935353 PMCID: PMC10072079 DOI: 10.1080/21645515.2023.2175519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023] Open
Abstract
The rapid increase in antibiotic resistance presents a dire situation necessitating the need for alternative therapeutic agents. Among the current alternative therapies, phage therapy (PT) is promising. This review extensively summarizes preclinical PT approaches in various in-vivo models. PT has been evaluated in several recent clinical trials. However, there are still several unanswered concerns due to a lack of appropriate regulation and pharmacokinetic data regarding the application of phages in human therapeutic procedures. In this review, we also presented the current state of PT and considered how animal models can be used to adapt these therapies for humans. The development of realistic solutions to circumvent these constraints is critical for advancing this technology.
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Affiliation(s)
- Fazal Mehmood Khan
- College of Civil and Transportation Engineering, Shenzhen University, Shenzhen, China.,Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, China.,Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, China.,Key Laboratory of Special Pathogens and Biosafety, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Prasanth Manohar
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, India
| | - Vijay Singh Gondil
- Key Laboratory of Special Pathogens and Biosafety, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei, China.,Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - Nancy Mehra
- Department of Pediatrics, Advanced Pediatrics Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Greater Kayode Oyejobi
- Key Laboratory of Special Pathogens and Biosafety, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei, China.,Department of Microbiology, Osun State University, Osogbo, Nigeria.,School of Pharmaceutical Sciences, Wuhan University, Wuhan, Hubei, China
| | - Nelson Odiwuor
- Key Laboratory of Special Pathogens and Biosafety, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei, China.,International College, University of Chinese Academy of Sciences, Beijing, China.,Microbiology, Sino-Africa Joint Research Centre, Nairobi, Kenya
| | - Tauseef Ahmad
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, China
| | - Guangtao Huang
- Department of Burn and Plastic Surgery, Shenzhen Institute of Translational Medicine, The First Affiliated Hospital of Shenzhen University, Shenzhen, China.,Department of Burns and Plastic Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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2
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Abstract
The oral cavity is an unique ecosystem formed by different structures, tissues, and a complex microbial community formed by hundreds of different species of bacteria, fungi, viruses, phages, and the candidate phyla radiation (CPR) group, all living in symbiosis with healthy individuals. In an opposite state, dental caries is a biofilm-mediated dysbiosis that involves changes in the core microbiome composition and function, which leads to the demineralization of tooth tissues due to the fermentation of dietary carbohydrates, producing acid by select oral bacteria. The cariogenic biofilm is typically characterized by bacterial species with the ability of adhering to the saliva-coated tooth surface, production of exopolysaccharides-rich matrix (which will limit the diffusion of acidic products of carbohydrate fermentation), and the ability of surviving in this acidic environment. Besides years of research and dental treatment, dental caries remains the most common chronic disease in children worldwide. This article aims to bring an insightful discussion about important questions that remain unanswered in the Cariology and Oral Microbiology fields, to move Science forward, characterize the interrelationships of these communities, and understand mechanistic functions between microorganisms and the host, therefore leading to translatable knowledge that benefits the provision of care to our pediatric patients.
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Affiliation(s)
- Apoena Aguiar Ribeiro
- Division of Diagnostic Sciences, Adams School of Dentistry, University of North Carolina, Chapel Hill, USA
- CONTACT Apoena Aguiar Ribeiro Division of Diagnostic Sciences, Adams School of Dentistry, University of North Carolina at Chapel Hill, 150 Dental Circle, Chapel Hill, CB 7450, USA
| | - Bruce J. Paster
- Department of Microbiology, The Forsyth Institute, Cambridge, Massachusetts, USA
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, USA
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3
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Plunder S, Burkard M, Lauer UM, Venturelli S, Marongiu L. Determination of phage load and administration time in simulated occurrences of antibacterial treatments. Front Med (Lausanne) 2022; 9:1040457. [PMID: 36388928 PMCID: PMC9650209 DOI: 10.3389/fmed.2022.1040457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 10/13/2022] [Indexed: 03/19/2024] Open
Abstract
The use of phages as antibacterials is becoming more and more common in Western countries. However, a successful phage-derived antibacterial treatment needs to account for additional features such as the loss of infective virions and the multiplication of the hosts. The parameters critical inoculation size (V F ) and failure threshold time (T F ) have been introduced to assure that the viral dose (V ϕ) and administration time (T ϕ) would lead to the extinction of the targeted bacteria. The problem with the definition of V F and T F is that they are non-linear equations with two unknowns; thus, obtaining their explicit values is cumbersome and not unique. The current study used machine learning to determine V F and T F for an effective antibacterial treatment. Within these ranges, a Pareto optimal solution of a multi-criterial optimization problem (MCOP) provided a pair of V ϕ and T ϕ to facilitate the user's work. The algorithm was tested on a series of in silico microbial consortia that described the outgrowth of a species at high cell density by another species initially present at low concentration. The results demonstrated that the MCOP-derived pairs of V ϕ and T ϕ could effectively wipe out the bacterial target within the context of the simulation. The present study also introduced the concept of mediated phage therapy, where targeting booster bacteria might decrease the virulence of a pathogen immune to phagial infection and highlighted the importance of microbial competition in attaining a successful antibacterial treatment. In summary, the present work developed a novel method for investigating phage/bacteria interactions that can help increase the effectiveness of the application of phages as antibacterials and ease the work of microbiologists.
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Affiliation(s)
- Steffen Plunder
- Department of Mathematics, University of Vienna, Vienna, Austria
| | - Markus Burkard
- Department of Nutritional Biochemistry, University of Hohenheim, Stuttgart, Germany
| | - Ulrich M. Lauer
- Department of Internal Medicine VIII, University Hospital Tübingen, Tübingen, Germany
| | - Sascha Venturelli
- Department of Nutritional Biochemistry, University of Hohenheim, Stuttgart, Germany
- Department of Vegetative and Clinical Physiology, Institute of Physiology, University Hospital Tübingen, Tübingen, Germany
| | - Luigi Marongiu
- Department of Nutritional Biochemistry, University of Hohenheim, Stuttgart, Germany
- Department of Internal Medicine VIII, University Hospital Tübingen, Tübingen, Germany
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4
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Walker AR, Shields RC. Investigating CRISPR spacer targets and their impact on genomic diversification of Streptococcus mutans. Front Genet 2022; 13:997341. [PMID: 36186424 PMCID: PMC9522601 DOI: 10.3389/fgene.2022.997341] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 08/17/2022] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas is a bacterial immune system that restricts the acquisition of mobile DNA elements. These systems provide immunity against foreign DNA by encoding CRISPR spacers that help target DNA if it re-enters the cell. In this way, CRISPR spacers are a type of molecular tape recorder of foreign DNA encountered by the host microorganism. Here, we extracted ∼8,000 CRISPR spacers from a collection of over three hundred Streptococcus mutans genomes. Phage DNA is a major target of S. mutans spacers. S. mutans strains have also generated immunity against mobile DNA elements such as plasmids and integrative and conjugative elements. There may also be considerable immunity generated against bacterial DNA, although the relative contribution of self-targeting versus bona fide intra- or inter-species targeting needs to be investigated further. While there was clear evidence that these systems have acquired immunity against foreign DNA, there appeared to be minimal impact on horizontal gene transfer (HGT) constraints on a species-level. There was little or no impact on genome size, GC content and ‘openness’ of the pangenome when comparing between S. mutans strains with low or high CRISPR spacer loads. In summary, while there is evidence of CRISPR spacer acquisition against self and foreign DNA, CRISPR-Cas does not act as a barrier on the expansion of the S. mutans accessory genome.
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Affiliation(s)
- Alejandro R. Walker
- Department of Oral Biology, University of Florida, Gainesville, FL, United States
| | - Robert C. Shields
- Department of Biological Sciences, Arkansas State University, Jonesboro, AR, United States
- *Correspondence: Robert C. Shields,
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Wolfoviz-Zilberman A, Kraitman R, Hazan R, Friedman M, Houri-Haddad Y, Beyth N. Phage Targeting Streptococcus mutans In Vitro and In Vivo as a Caries-Preventive Modality. Antibiotics (Basel) 2021; 10:antibiotics10081015. [PMID: 34439064 PMCID: PMC8389033 DOI: 10.3390/antibiotics10081015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/16/2021] [Accepted: 08/18/2021] [Indexed: 12/20/2022] Open
Abstract
Dental caries is a common infectious disease worldwide. Current conventional therapies lack specific antimicrobial effects against Streptococcus mutans, a key bacterium that induces caries. A promising alternative approach is bacteriophage (phage) therapy. Recently, SMHBZ8 phage targeting S. mutans was isolated and characterized. The aim of this study was to evaluate the caries-prevention efficacy of SMHBZ8 using in vitro and in vivo caries models. Hemi-mandibles dissected from euthanized healthy mice were subjected to caries-promoting conditions in vitro. Jaws treated with phage therapy in suspension and in formulation with a sustained-release delivery system showed no carious lesions, similar to control and chlorhexidine-treated jaws. Subsequently, SMHBZ8 phage suspension also prevented carious lesion development in a murine caries model in vivo. In both models, caries lesions were analyzed clinically and radiographically by µCT scans. This study shows how SMHBZ8 phage therapy targeting S. mutans can serve as an efficient caries-prevention modality, in suspension or with a sustained-release delivery system, by in vitro and in vivo mouse models.
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Affiliation(s)
- Amit Wolfoviz-Zilberman
- Department of Prosthodontics, Hadassah Medical Center, Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem 9112001, Israel; (A.W.-Z.); (R.K.); (Y.H.-H.)
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem 9112001, Israel;
| | - Reut Kraitman
- Department of Prosthodontics, Hadassah Medical Center, Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem 9112001, Israel; (A.W.-Z.); (R.K.); (Y.H.-H.)
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem 9112001, Israel;
| | - Ronen Hazan
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem 9112001, Israel;
| | - Michael Friedman
- Department of Pharmaceutics, The Institute for Drug Research, Faculty of Medicine, The Hebrew University, Jerusalem 91120, Israel;
| | - Yael Houri-Haddad
- Department of Prosthodontics, Hadassah Medical Center, Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem 9112001, Israel; (A.W.-Z.); (R.K.); (Y.H.-H.)
| | - Nurit Beyth
- Department of Prosthodontics, Hadassah Medical Center, Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem 9112001, Israel; (A.W.-Z.); (R.K.); (Y.H.-H.)
- Correspondence:
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6
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Abstract
Streptococcus mutans strain P42S possesses a type II-A CRISPR-Cas system that protects against phage infection and plasmid transformation. The analysis of 293 bacteriophage-insensitive mutants (BIMs) obtained upon exposure to the virulent phage M102AD revealed the acquisition of 399 unique spacers, including several ectopic spacer acquisitions and a few cases of native spacer deletions. The acquisition of multiple spacers was also observed and appears to be mostly due to priming, which has been rarely reported for type II-A systems. Analyses of the acquired spacers indicated that 88% of them are identical to a region of the phage M102AD genome. The remaining 12% of spacers had mismatches with the phage genome, primarily at the 5′ end of the spacer, leaving the seed sequence at the 3′ end largely intact. When a high multiplicity of infection (MOI) was used in the phage challenge assays, we also observed the emergence of CRISPR BIMs that, in addition to the acquisition of new spacers, displayed a reduced phage adsorption phenotype. While CRISPR-Cas and adsorption resistance work in tandem to protect S. mutans P42S against phage M102AD, nonidentified antiviral mechanisms are also likely at play in this strain. IMPORTANCE Bacteria are under the constant threat of viral predation and have therefore developed several defense mechanisms, including CRISPR-Cas systems. While studies on the mode of action of CRISPR-Cas systems have already provided great insights into phage-bacterium interactions, still more information is needed on the biology of these systems. The additional characterization of the type II-A CRISPR-Cas system of Streptococcus mutans P42S in this study provides novel information on the spacer acquisition step, especially regarding protospacer-adjacent motif (PAM) recognition, multiple-spacer acquisition, and priming.
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7
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Ben-Zaken H, Kraitman R, Coppenhagen-Glazer S, Khalifa L, Alkalay-Oren S, Gelman D, Ben-Gal G, Beyth N, Hazan R. Isolation and Characterization of Streptococcus mutans Phage as a Possible Treatment Agent for Caries. Viruses 2021; 13:825. [PMID: 34063251 PMCID: PMC8147482 DOI: 10.3390/v13050825] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/27/2021] [Accepted: 04/29/2021] [Indexed: 12/22/2022] Open
Abstract
Streptococcus mutans is a key bacterium in dental caries, one of the most prevalent chronic infectious diseases. Conventional treatment fails to specifically target the pathogenic bacteria, while tending to eradicate commensal bacteria. Thus, caries remains one of the most common and challenging diseases. Phage therapy, which involves the use of bacterial viruses as anti-bacterial agents, has been gaining interest worldwide. Nevertheless, to date, only a few phages have been isolated against S. mutans. In this study, we describe the isolation and characterization of a new S. mutans phage, termed SMHBZ8, from hundreds of human saliva samples that were collected, filtered, and screened. The SMHBZ8 genome was sequenced and analyzed, visualized by TEM, and its antibacterial properties were evaluated in various states. In addition, we tested the lytic efficacy of SMHBZ8 against S. mutans in a human cariogenic dentin model. The isolation and characterization of SMHBZ8 may be the first step towards developing a potential phage therapy for dental caries.
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Affiliation(s)
- Hadar Ben-Zaken
- Department of Prosthodontics, Hadassah School of Dental Medicine, Hebrew University, Jerusalem 91120, Israel; (H.B.-Z.); (R.K.); (G.B.-G.); (N.B.)
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Sciences, School of Dental Medicine, The Hebrew University, Jerusalem 91120, Israel; (S.C.-G.); (L.K.); (S.A.-O.); (D.G.)
| | - Reut Kraitman
- Department of Prosthodontics, Hadassah School of Dental Medicine, Hebrew University, Jerusalem 91120, Israel; (H.B.-Z.); (R.K.); (G.B.-G.); (N.B.)
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Sciences, School of Dental Medicine, The Hebrew University, Jerusalem 91120, Israel; (S.C.-G.); (L.K.); (S.A.-O.); (D.G.)
| | - Shunit Coppenhagen-Glazer
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Sciences, School of Dental Medicine, The Hebrew University, Jerusalem 91120, Israel; (S.C.-G.); (L.K.); (S.A.-O.); (D.G.)
| | - Leron Khalifa
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Sciences, School of Dental Medicine, The Hebrew University, Jerusalem 91120, Israel; (S.C.-G.); (L.K.); (S.A.-O.); (D.G.)
| | - Sivan Alkalay-Oren
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Sciences, School of Dental Medicine, The Hebrew University, Jerusalem 91120, Israel; (S.C.-G.); (L.K.); (S.A.-O.); (D.G.)
| | - Daniel Gelman
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Sciences, School of Dental Medicine, The Hebrew University, Jerusalem 91120, Israel; (S.C.-G.); (L.K.); (S.A.-O.); (D.G.)
| | - Gilad Ben-Gal
- Department of Prosthodontics, Hadassah School of Dental Medicine, Hebrew University, Jerusalem 91120, Israel; (H.B.-Z.); (R.K.); (G.B.-G.); (N.B.)
| | - Nurit Beyth
- Department of Prosthodontics, Hadassah School of Dental Medicine, Hebrew University, Jerusalem 91120, Israel; (H.B.-Z.); (R.K.); (G.B.-G.); (N.B.)
| | - Ronen Hazan
- Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Sciences, School of Dental Medicine, The Hebrew University, Jerusalem 91120, Israel; (S.C.-G.); (L.K.); (S.A.-O.); (D.G.)
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8
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Chen J, Chen Z, Yuan K, Huang Z, Mao M. Recombinant bacteriophage T4 Rnl1 impacts Streptococcus mutans biofilm formation. J Oral Microbiol 2020; 13:1860398. [PMID: 33456722 PMCID: PMC7782964 DOI: 10.1080/20002297.2020.1860398] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Bacteriophage T4 RNA ligase 1 (T4 Rnl1) can be stably expressed in many bacteria and has been reported to affect the bioactivity of the host bacteria. Recently, we constructed bacteriophage T4 Rnl1 expressing system in Streptococcus mutans, a crucial biofilm-forming and dental caries-causing oral pathogen. Here, we characterized the function of recombinant bacteriophage T4 Rnl1 in biofilm formation of S. mutans. The T4 Rnl1 mutant exhibited similar growth phenotype but resulted in a significant reduction of biofilm biomass compared to wild type strain and empty plasmid carrying strain. The abnormal biofilm of the T4 Rnl1 mutant harbored loose bacterial clusters with defective production and distribution of exopolysaccharides. Moreover, the expression of several biofilm formation-associated genes was dysregulated at mRNA level in the T4 Rnl1 mutant. These results reveal that the bacteriophage T4 Rnl1 exert antibiofilm activities against the cariogenic bacterium S. mutans, which impacts the spatial organization of the exopolysaccharides and further impairs the three-dimensional biofilm architecture. These findings implicate that manipulation of bacteriophage T4 Rnl1, a biological tool used for RNA ligation, will provide a promising approach to cariogenic biofilm control.
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Affiliation(s)
- Juxiu Chen
- Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China.,National Clinical Research Center for Oral Diseases, Shanghai, China.,Department of Endodontics, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhanyi Chen
- Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China.,National Clinical Research Center for Oral Diseases, Shanghai, China.,Department of Endodontics, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Keyong Yuan
- Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China.,National Clinical Research Center for Oral Diseases, Shanghai, China.,Department of Endodontics, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhengwei Huang
- Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China.,National Clinical Research Center for Oral Diseases, Shanghai, China.,Department of Endodontics, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mengying Mao
- Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China.,National Clinical Research Center for Oral Diseases, Shanghai, China.,Department of Endodontics, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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9
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Abstract
CRISPR-Cas is one of the mechanisms used by bacteria to defend against viral predation. Increasing our knowledge of the biology and diversity of CRISPR-Cas systems will also improve our understanding of virus-bacterium interactions. As CRISPR-Cas systems acquiring novel immunities under laboratory conditions are rare, Streptococcus mutans strain P42S provides an alternative model to study the adaptation step, which is still the least understood step in CRISPR-Cas biology. Furthermore, the availability of a natural Cas9 protein recognizing an AT-rich PAM opens up new avenues for genome editing purposes. Streptococcus mutans and its virulent phages are important members of the human oral microbiota. S. mutans is also the primary causal agent of dental caries. To survive in this ecological niche, S. mutans must encode phage defense mechanisms, which include CRISPR-Cas systems. Here, we describe the CRISPR-Cas type II-A system of S. mutans strain P42S, which was found to display natural adaptation and interference activity in response to phage infection and plasmid transformation. Newly acquired spacers were integrated both at the 5′ end of the CRISPR locus and ectopically. In comparisons of the cas genes of P42S to those of other strains of S. mutans, cas1, cas2, and csn2 appear to be highly conserved within the species. However, more diversity was observed with cas9. While the nuclease domains of S. mutans Cas9 (SmCas9) are conserved, the C terminus of the protein, including the protospacer adjacent motif (PAM) recognition domain, is less conserved. In support of these findings, we experimentally demonstrated that the PAMs associated with SmCas9 of strain P42S are NAA and NGAA. These PAMs are different from those previously reported for the CRISPR-Cas system of the model strain S. mutans UA159. This study illustrates the diversity of CRISPR-Cas type II-A systems that can be found within the same bacterial species. IMPORTANCE CRISPR-Cas is one of the mechanisms used by bacteria to defend against viral predation. Increasing our knowledge of the biology and diversity of CRISPR-Cas systems will also improve our understanding of virus-bacterium interactions. As CRISPR-Cas systems acquiring novel immunities under laboratory conditions are rare, Streptococcus mutans strain P42S provides an alternative model to study the adaptation step, which is still the least understood step in CRISPR-Cas biology. Furthermore, the availability of a natural Cas9 protein recognizing an AT-rich PAM opens up new avenues for genome editing purposes.
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10
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Labrie SJ, Mosterd C, Loignon S, Dupuis MÈ, Desjardins P, Rousseau GM, Tremblay DM, Romero DA, Horvath P, Fremaux C, Moineau S. A mutation in the methionine aminopeptidase gene provides phage resistance in Streptococcus thermophilus. Sci Rep 2019; 9:13816. [PMID: 31554834 PMCID: PMC6761271 DOI: 10.1038/s41598-019-49975-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 08/31/2019] [Indexed: 12/26/2022] Open
Abstract
Streptococcus thermophilus is a lactic acid bacterium widely used by the dairy industry for the manufacture of yogurt and specialty cheeses. It is also a Gram-positive bacterial model to study phage-host interactions. CRISPR-Cas systems are one of the most prevalent phage resistance mechanisms in S. thermophilus. Little information is available about other host factors involved in phage replication in this food-grade streptococcal species. We used the model strain S. thermophilus SMQ-301 and its virulent phage DT1, harboring the anti-CRISPR protein AcrIIA6, to show that a host gene coding for a methionine aminopeptidase (metAP) is necessary for phage DT1 to complete its lytic cycle. A single mutation in metAP provides S. thermophilus SMQ-301 with strong resistance against phage DT1. The mutation impedes a late step of the lytic cycle since phage adsorption, DNA replication, and protein expression were not affected. When the mutated strain was complemented with the wild-type version of the gene, the phage sensitivity phenotype was restored. When this mutation was introduced into other S. thermophilus strains it provided resistance against cos-type (Sfi21dt1virus genus) phages but replication of pac-type (Sfi11virus genus) phages was not affected. The mutation in the gene coding for the MetAP induces amino acid change in a catalytic domain conserved across many bacterial species. Introducing the same mutation in Streptococcus mutans also provided a phage resistance phenotype, suggesting the wide-ranging importance of the host methionine aminopeptidase in phage replication.
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Affiliation(s)
- Simon J Labrie
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec City, QC, G1V 0A6, Canada.,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada.,SyntBioLab Inc., 4820-250, rue de la Pascaline, Lévis, G6W 0L9, Canada
| | - Cas Mosterd
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec City, QC, G1V 0A6, Canada.,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada
| | - Stéphanie Loignon
- Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada.,Félix d'Hérelle Reference Center for Bacterial Viruses, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada
| | - Marie-Ève Dupuis
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec City, QC, G1V 0A6, Canada.,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada
| | - Philippe Desjardins
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec City, QC, G1V 0A6, Canada
| | - Geneviève M Rousseau
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec City, QC, G1V 0A6, Canada.,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada
| | - Denise M Tremblay
- Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada.,Félix d'Hérelle Reference Center for Bacterial Viruses, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada
| | - Dennis A Romero
- DuPont Nutrition and Biosciences, 3329 Agriculture Dr, Madison, WI, 53716, USA
| | - Philippe Horvath
- DuPont Nutrition and Biosciences, BP10, Dangé-Saint-Romain, 86220, France
| | - Christophe Fremaux
- DuPont Nutrition and Biosciences, BP10, Dangé-Saint-Romain, 86220, France
| | - Sylvain Moineau
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec City, QC, G1V 0A6, Canada. .,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada. .,Félix d'Hérelle Reference Center for Bacterial Viruses, Faculté de médecine dentaire, Université Laval, Québec City, QC, G1V 0A6, Canada.
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11
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A Linear Plasmid-Like Prophage of Actinomyces odontolyticus Promotes Biofilm Assembly. Appl Environ Microbiol 2018; 84:AEM.01263-18. [PMID: 29915115 DOI: 10.1128/aem.01263-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 06/11/2018] [Indexed: 01/08/2023] Open
Abstract
The human oral cavity is home to a large number of bacteria and bacteriophages (phages). However, the biology of oral phages as members of the human microbiome is not well understood. Recently, we isolated Actinomyces odontolyticus subsp. actinosynbacter strain XH001 from the human oral cavity, and genomic analysis revealed the presence of an intact prophage named xhp1. Here, we demonstrated that xhp1 is a linear plasmid-like prophage, which is a newly identified phage of A. odontolyticus The prophage xhp1 genome is a 35-kb linear double-stranded DNA with 10-bp single-stranded, 3' cohesive ends. xhp1 exists extrachromosomally, with an estimated copy number of 5. Annotation of xhp1 revealed 54 open reading frames, while phylogenetic analysis suggests that it has limited similarity with other phages. xhp1 phage particles can be induced by mitomycin C and belong to the Siphoviridae family, according to transmission electron microscopic examination. The released xhp1 particles can reinfect the xhp1-cured XH001 strain and result in tiny blurry plaques. Moreover, xhp1 promotes XH001 biofilm formation through spontaneous induction and the release of host extracellular DNA (eDNA). In conclusion, we identified a linear plasmid-like prophage of A. odontolyticus, which enhances bacterial host biofilm assembly and could be beneficial to the host for its persistence in the oral cavity.IMPORTANCE The biology of phages as members of the human oral microbiome is understudied. Here, we report the characterization of xhp1, a novel linear plasmid-like prophage identified from a human oral isolate, Actinomyces odontolyticus subsp. actinosynbacter strain XH001. xhp1 can be induced and reinfect xhp1-cured XH001. The spontaneous induction of xhp1 leads to the lysis of a subpopulation of bacterial hosts and the release of eDNA that promotes biofilm assembly, thus potentially contributing to the persistence of A. odontolyticus within the oral cavity.
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Harada LK, Silva EC, Campos WF, Del Fiol FS, Vila M, Dąbrowska K, Krylov VN, Balcão VM. Biotechnological applications of bacteriophages: State of the art. Microbiol Res 2018; 212-213:38-58. [DOI: 10.1016/j.micres.2018.04.007] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 04/16/2018] [Accepted: 04/25/2018] [Indexed: 02/06/2023]
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Fu T, Fan X, Long Q, Deng W, Song J, Huang E. Comparative analysis of prophages in Streptococcus mutans genomes. PeerJ 2017; 5:e4057. [PMID: 29158986 PMCID: PMC5695247 DOI: 10.7717/peerj.4057] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 10/27/2017] [Indexed: 01/28/2023] Open
Abstract
Prophages have been considered genetic units that have an intimate association with novel phenotypic properties of bacterial hosts, such as pathogenicity and genomic variation. Little is known about the genetic information of prophages in the genome of Streptococcus mutans, a major pathogen of human dental caries. In this study, we identified 35 prophage-like elements in S. mutans genomes and performed a comparative genomic analysis. Comparative genomic and phylogenetic analyses of prophage sequences revealed that the prophages could be classified into three main large clusters: Cluster A, Cluster B, and Cluster C. The S. mutans prophages in each cluster were compared. The genomic sequences of phismuN66-1, phismuNLML9-1, and phismu24-1 all shared similarities with the previously reported S. mutans phages M102, M102AD, and ϕAPCM01. The genomes were organized into seven major gene clusters according to the putative functions of the predicted open reading frames: packaging and structural modules, integrase, host lysis modules, DNA replication/recombination modules, transcriptional regulatory modules, other protein modules, and hypothetical protein modules. Moreover, an integrase gene was only identified in phismuNLML9-1 prophages.
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Affiliation(s)
- Tiwei Fu
- College of Stomatology, Chongqing Medical University, Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Xiangyu Fan
- School of Biological Science and Technology, University of Jinan, Jinan, China
| | - Quanxin Long
- Key Laboratory of Molecular Biology for Infectious Diseases of Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Wanyan Deng
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Jinlin Song
- College of Stomatology, Chongqing Medical University, Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Enyi Huang
- College of Stomatology, Chongqing Medical University, Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
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YMC-2011, a Temperate Phage of Streptococcus salivarius 57.I. Appl Environ Microbiol 2017; 83:AEM.03186-16. [PMID: 28062463 DOI: 10.1128/aem.03186-16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 01/04/2017] [Indexed: 11/20/2022] Open
Abstract
Streptococcus salivarius is an abundant isolate of the oral cavity. The genome of S. salivarius 57.I consists of a 2-Mb chromosome and a 40,758-bp circular molecule, designated YMC-2011. Annotation of YMC-2011 revealed 55 open reading frames, most of them associated with phage production, although plaque formation is not observed in S. salivarius 57.I after lytic induction using mitomycin C. Results from Southern hybridization and quantitative real-time PCR confirmed that YMC-2011 exists extrachromosomally, with an estimated copy number of 3 to 4. Phage particles were isolated from the supernatant of mitomycin C-treated S. salivarius 57.I cultures, and transmission electron microscopic examination indicated that YMC-2011 belongs to the Siphoviridae family. Phylogenetic analysis suggests that phage YMC-2011 and the cos-type phages of Streptococcus thermophilus originated from a common ancestor. An extended -10 element (p L ) and a σ70-like promoter (p R ) were mapped 5' to Ssal_phage00013 (encoding a CI-like repressor) and Ssal_phage00014 (encoding a hypothetical protein), respectively, using 5' rapid amplification of cDNA ends, indicating that YMC-2011 transcribes at least two mRNAs in opposite orientations. Studies using promoter-chloramphenicol acetyltransferase reporter gene fusions revealed that p R , but not p L , was sensitive to mitomycin C induction, suggesting that the switch from lysogenic growth to lytic growth was controlled mainly by the activity of these two promoters. In conclusion, a lysogenic state is maintained in S. salivarius 57.I, presumably by the repression of genes encoding proteins for lytic growth.IMPORTANCE The movement of mobile genetic elements such as bacteriophages and the establishment of lysogens may have profound effects on the balance of microbial ecology where lysogenic bacteria reside. The discovery of phage YMC-2011 from Streptococcus salivarius 57.I suggests that YMC-2011 and Streptococcus thermophilus-infecting phages share an ancestor. Although S. salivarius and S. thermophilus are close phylogenetically, S. salivarius is a natural inhabitant of the human mouth, whereas S. thermophilus is commonly found in the mammary mucosa of bovine species. Thus, the identification of YMC-2011 suggests that horizontal gene transfer via phage infection could take place between species from different ecological niches.
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Szafrański SP, Winkel A, Stiesch M. The use of bacteriophages to biocontrol oral biofilms. J Biotechnol 2017; 250:29-44. [PMID: 28108235 DOI: 10.1016/j.jbiotec.2017.01.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 01/09/2017] [Accepted: 01/10/2017] [Indexed: 12/15/2022]
Abstract
Infections induced by oral biofilms include caries, as well as periodontal, and peri-implant disease, and may influence quality of life, systemic health, and expenditure. As bacterial biofilms are highly resistant and resilient to conventional antibacterial therapy, it has been difficult to combat these infections. An innovative alternative to the biocontrol of oral biofilms could be to use bacteriophages or phages, the viruses of bacteria, which are specific, non-toxic, self-proliferating, and can penetrate into biofilms. Phages for Actinomyces naeslundii, Aggregatibacter actinomycetemcomitans, Enterococcus faecalis, Fusobacterium nucleatum, Lactobacillus spp., Neisseria spp., Streptococcus spp., and Veillonella spp. have been isolated and characterised. Recombinant phage enzymes (lysins) have been shown to lyse A. naeslundii and Streptococcus spp. However, only a tiny fraction of available phages and their lysins have been explored so far. The unique properties of phages and their lysins make them promising but challenging antimicrobials. The genetics and biology of phages have to be further explored in order to determine the most effective way of applying them. Studying the effect of phages and lysins on multispecies biofilms should pave the way for microbiota engineering and microbiota-based therapy.
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Affiliation(s)
- Szymon P Szafrański
- Lower Saxony Centre for Biomedical Engineering, Implant Research and Development (NIFE), Stadtfelddamm 34, D-30625 Hannover, Germany; Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School (MHH), Carl-Neuberg-Strasse 1, D-30625 Hannover, Germany.
| | - Andreas Winkel
- Lower Saxony Centre for Biomedical Engineering, Implant Research and Development (NIFE), Stadtfelddamm 34, D-30625 Hannover, Germany; Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School (MHH), Carl-Neuberg-Strasse 1, D-30625 Hannover, Germany
| | - Meike Stiesch
- Lower Saxony Centre for Biomedical Engineering, Implant Research and Development (NIFE), Stadtfelddamm 34, D-30625 Hannover, Germany; Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School (MHH), Carl-Neuberg-Strasse 1, D-30625 Hannover, Germany.
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Antibiofilm Activities of a Novel Chimeolysin against Streptococcus mutans under Physiological and Cariogenic Conditions. Antimicrob Agents Chemother 2016; 60:7436-7443. [PMID: 27736755 DOI: 10.1128/aac.01872-16] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 10/02/2016] [Indexed: 01/21/2023] Open
Abstract
Streptococcus mutans often survives as a biofilm on the tooth surface and contributes to the development of dental caries. We investigated the efficacy of ClyR, an engineered chimeolysin, against S. mutans biofilms under physiological and cariogenic conditions. Susceptibility tests showed that ClyR was active against all clinical S. mutans isolates tested as well as S. mutans biofilms that displayed resistance to penicillin. The S. mutans biofilms that formed on hydroxyapatite discs under physiological sugar conditions and cariogenic conditions were reduced ∼2 logs and 3 logs after treatment with 100 μg/ml ClyR, respectively. In comparison, only a 1-log reduction was observed in the chlorhexidine gluconate (ChX)-treated group, and no killing effect was observed in the NaF-treated group. A mouse dental colonization model showed that repeated use of ClyR for 3 weeks (5 μg/day) reduced the number of colonized S. mutans cells in the dental plaques significantly (P < 0.05) and had no harmful effects on the mice. Furthermore, toxicity was not noted at concentrations exceeding those used for the in vitro and in vivo studies, and ClyR-specific antibodies could not be detected in mouse saliva after repeated use of ClyR in the oral cavity. Our data collectively demonstrate that ClyR is active against S. mutans biofilms both in vitro and in vivo, thus representing a preventative or therapeutic agent for use against dental caries.
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Isolation of a Novel Phage with Activity against Streptococcus mutans Biofilms. PLoS One 2015; 10:e0138651. [PMID: 26398909 PMCID: PMC4580409 DOI: 10.1371/journal.pone.0138651] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 09/02/2015] [Indexed: 01/21/2023] Open
Abstract
Streptococcus mutans is one of the principal agents of caries formation mainly, because of its ability to form biofilms at the tooth surface. Bacteriophages (phages) are promising antimicrobial agents that could be used to prevent or treat caries formation by S. mutans. The aim of this study was to isolate new S. mutans phages and to characterize their antimicrobial properties. A new phage, ɸAPCM01, was isolated from a human saliva sample. Its genome was closely related to the only two other available S. mutans phage genomes, M102 and M102AD. ɸAPCM01 inhibited the growth of S. mutans strain DPC6143 within hours in broth and in artificial saliva at multiplicity of infections as low as 2.5x10-5. In the presence of phage ɸAPCM01 the metabolic activity of a S. mutans biofilm was reduced after 24 h of contact and did not increased again after 48 h, and the live cells in the biofilm decreased by at least 5 log cfu/ml. Despite its narrow host range, this newly isolated S. mutans phage exhibits promising antimicrobial properties.
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Role of the Streptococcus mutans CRISPR-Cas systems in immunity and cell physiology. J Bacteriol 2014; 197:749-61. [PMID: 25488301 DOI: 10.1128/jb.02333-14] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas systems provide adaptive microbial immunity against invading viruses and plasmids. The cariogenic bacterium Streptococcus mutans UA159 has two CRISPR-Cas systems: CRISPR1 (type II-A) and CRISPR2 (type I-C) with several spacers from both CRISPR cassettes matching sequences of phage M102 or genomic sequences of other S. mutans. The deletion of the cas genes of CRISPR1 (ΔC1S), CRISPR2 (ΔC2E), or both CRISPR1+2 (ΔC1SC2E) or the removal of spacers 2 and 3 (ΔCR1SP13E) in S. mutans UA159 did not affect phage sensitivity when challenged with virulent phage M102. Using plasmid transformation experiments, we demonstrated that the CRISPR1-Cas system inhibits transformation of S. mutans by the plasmids matching the spacers 2 and 3. Functional analysis of the cas deletion mutants revealed that in addition to a role in plasmid targeting, both CRISPR systems also contribute to the regulation of bacterial physiology in S. mutans. Compared to wild-type cells, the ΔC1S strain displayed diminished growth under cell membrane and oxidative stress, enhanced growth under low pH, and had reduced survival under heat shock and DNA-damaging conditions, whereas the ΔC2E strain exhibited increased sensitivity to heat shock. Transcriptional analysis revealed that the two-component signal transduction system VicR/K differentially modulates expression of cas genes within CRISPR-Cas systems, suggesting that VicR/K might coordinate the expression of two CRISPR-Cas systems. Collectively, we provide in vivo evidence that the type II-A CRISPR-Cas system of S. mutans may be targeted to manipulate its stress response and to influence the host to control the uptake and dissemination of antibiotic resistance genes.
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Bai Q, Zhang W, Yang Y, Tang F, Nguyen X, Liu G, Lu C. Characterization and genome sequencing of a novel bacteriophage infecting Streptococcus agalactiae with high similarity to a phage from Streptococcus pyogenes. Arch Virol 2013; 158:1733-41. [PMID: 23515875 DOI: 10.1007/s00705-013-1667-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 02/06/2013] [Indexed: 10/27/2022]
Abstract
A novel bacteriophage, JX01, specifically infecting bovine Streptococcus agalactiae was isolated from milk of mastitis-affected cattle. The phage morphology showed that JX01 belongs to the family Siphoviridae, and this phage demonstrated a broad host range. Microbiological characterization demonstrated that nearly 90 % of JX01 phage particles were adsorbed after 2.5 min of incubation, that the burst size was 20 virions released per infected host cell, and that there was a latent period of 30 min. JX01 was thermal sensitive and showed acid and alkaline resistance (pH 3-11). The genome of JX01 was found to consist of a linear, double-stranded 43,028-bp DNA molecule with a GC content of 36.81 % and 70 putative open reading frames (ORFs) plus one tRNA. Comparative genome analysis revealed high similarity between JX01 and the prophage 315.2 of Streptococcus pyogenes.
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Affiliation(s)
- Qinqin Bai
- Key Lab of Animal Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
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Nelson OW, Garrity GM. Genome sequences published outside of Standards in Genomic Sciences, March-April 2012. Stand Genomic Sci 2012. [PMCID: PMC3387800 DOI: 10.4056/sigs.2836114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The purpose of this table is to provide the community with a citable record of publications of ongoing genome sequencing projects that have led to a publication in the scientific literature. While our goal is to make the list complete, there is no guarantee that we may have omitted one or more publications appearing in this time frame. Readers and authors who wish to have publications added to subsequent versions of this list are invited to provide the bibliographic data for such references to the SIGS editorial office.
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Affiliation(s)
- Oranmiyan W. Nelson
- 1Editorial Office, Standards in Genomic Sciences and Department of Microbiology, Michigan State University, East Lansing, MI, USA
| | - George M. Garrity
- 1Editorial Office, Standards in Genomic Sciences and Department of Microbiology, Michigan State University, East Lansing, MI, USA
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