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Rampersadh K, Salie MT, Engel KC, Moodley C, Zühlke LJ, Engel ME. Presence of Group A streptococcus frequently assayed virulence genes in invasive disease: a systematic review and meta-analysis. Front Cell Infect Microbiol 2024; 14:1337861. [PMID: 39055978 PMCID: PMC11270091 DOI: 10.3389/fcimb.2024.1337861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 01/18/2024] [Indexed: 07/28/2024] Open
Abstract
Introduction It is currently unclear what the role of Group A streptococcus (GAS) virulence factors (VFs) is in contributing to the invasive potential of GAS. This work investigated the evidence for the association of GAS VFs with invasive disease. Methods We employed a broad search strategy for studies reporting the presence of GAS VFs in invasive and non-invasive GAS disease. Data were independently extracted by two reviewers, quality assessed, and meta-analyzed using Stata®. Results A total of 32 studies reported on 45 putative virulence factors [invasive (n = 3,236); non-invasive (n = 5,218)], characterized by polymerase chain reaction (PCR) (n = 30) and whole-genome sequencing (WGS) (n = 2). The risk of bias was rated as low and moderate, in 23 and 9 studies, respectively. Meta-,analyses of high-quality studies (n = 23) revealed a significant association of speM [OR, 1.64 (95%CI, 1.06; 2.52)] with invasive infection. Meta-analysis of WGS studies demonstrated a significant association of hasA [OR, 1.91 (95%CI, 1.36; 2.67)] and speG [OR, 2.83 (95%CI, 1.63; 4.92)] with invasive GAS (iGAS). Meta-analysis of PCR studies indicated a significant association of speA [OR, 1.59 (95%CI, 1.10; 2.30)] and speK [OR, 2.95 (95%CI, 1.81; 4.80)] with invasive infection. A significant inverse association was observed between prtf1 [OR, 0.42 (95%CI, 0.20; 0.87)] and invasive infection. Conclusion This systematic review and genomic meta-analysis provides evidence of a statistically significant association with invasive infection for the hasA gene, while smeZ, ssa, pnga3, sda1, sic, and NaDase show statistically significantly inverse associations with invasive infection. SpeA, speK, and speG are associated with GAS virulence; however, it is unclear if they are markers of invasive infection. This work could possibly aid in developing preventative strategies.
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Affiliation(s)
- Kimona Rampersadh
- AFROStrep Research Group, Department of Medicine and Cape Heart Institute, University of Cape Town, Cape Town, South Africa
| | - M. Taariq Salie
- AFROStrep Research Group, Department of Medicine and Cape Heart Institute, University of Cape Town, Cape Town, South Africa
| | - Kelin C. Engel
- AFROStrep Research Group, Department of Medicine and Cape Heart Institute, University of Cape Town, Cape Town, South Africa
| | - Clinton Moodley
- Department of Pathology, Division of Medical Microbiology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- The National Health Laboratory Service, Microbiology, Groote Schuur Hospital, Cape Town, South Africa
| | - Liesl J. Zühlke
- Division of Paediatric Cardiology, Department of Paediatrics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- South African Medical Research Council, Parrow Valley, Cape Town, South Africa
| | - Mark E. Engel
- AFROStrep Research Group, Department of Medicine and Cape Heart Institute, University of Cape Town, Cape Town, South Africa
- South African Medical Research Council, Parrow Valley, Cape Town, South Africa
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Asakereh I, Rutbeek NR, Singh M, Davidson D, Prehna G, Khajehpour M. The Streptococcus phage protein paratox is an intrinsically disordered protein. Protein Sci 2024; 33:e5037. [PMID: 38801244 PMCID: PMC11129628 DOI: 10.1002/pro.5037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 05/09/2024] [Accepted: 05/10/2024] [Indexed: 05/29/2024]
Abstract
The bacteriophage protein paratox (Prx) blocks quorum sensing in its streptococcal host by directly binding the signal receptor and transcription factor ComR. This reduces the ability of Streptococcus to uptake environmental DNA and protects phage DNA from damage by recombination. Past work characterizing the Prx:ComR molecular interaction revealed that paratox adopts a well-ordered globular fold when bound to ComR. However, solution-state biophysical measurements suggested that Prx may be conformationally dynamic. To address this discrepancy, we investigated the stability and dynamic properties of Prx in solution using circular dichroism, nuclear magnetic resonance, and several fluorescence-based protein folding assays. Our work shows that under dilute buffer conditions Prx is intrinsically disordered. We also show that the addition of kosmotropic salts or protein stabilizing osmolytes induces Prx folding. However, the solute stabilized fold is different from the conformation Prx adopts when it is bound to ComR. Furthermore, we have characterized Prx folding thermodynamics and folding kinetics through steady-state fluorescence and stopped flow kinetic measurements. Our results show that Prx is a highly dynamic protein in dilute solution, folding and refolding within the 10 ms timescale. Overall, our results demonstrate that the streptococcal phage protein Prx is an intrinsically disordered protein in a two-state equilibrium with a solute-stabilized folded form. Furthermore, the solute-stabilized fold is likely the predominant form of Prx in a solute-crowded bacterial cell. Finally, our work suggests that Prx binds and inhibits ComR, and thus quorum sensing in Streptococcus, by a combination of conformational selection and induced-fit binding mechanisms.
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Affiliation(s)
- Iman Asakereh
- Department of ChemistryUniversity of ManitobaWinnipegManitobaCanada
| | - Nicole R. Rutbeek
- Department of MicrobiologyUniversity of ManitobaWinnipegManitobaCanada
| | - Manvir Singh
- Department of ChemistryUniversity of ManitobaWinnipegManitobaCanada
| | - David Davidson
- Department of ChemistryUniversity of ManitobaWinnipegManitobaCanada
| | - Gerd Prehna
- Department of MicrobiologyUniversity of ManitobaWinnipegManitobaCanada
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Tatsuno I, Isaka M, Hasegawa T. Association of CovRS two-component regulatory system with NADase induction by Clindamycin treatment in Streptococcus pyogenes. Jpn J Infect Dis 2024:JJID.2023.451. [PMID: 38556301 DOI: 10.7883/yoken.jjid.2023.451] [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: 04/02/2024]
Abstract
The administration of high-dose clindamycin (CLI) along with penicillin is recommended for the treatment of streptococcal toxic shock syndrome (STSS). However, CLI-resistant strains have been identified worldwide. Firstly, in this study, some CLI-resistant strains showed increased extracellular activities of the NAD- glycohydrolase (NADase) exotoxin after CLI treatment. This result supported our previous conclusion that not only CLI-susceptible but also CLI-resistant S. pyogenes strains show the CLI-dependent NADase induction. Secondary, using the 13 types of two- component-sensor knockout strains derived from a CLI-susceptible strain 1529 that has the CLI-dependent NADase induction phenotype, we investigated the mechanism of action. Among the knockout strains, only 1529ΔcovS lost the phenotype. In addition, 1529ΔspeB, 1529Δmga, and 1529Δrgg retained the CLI-dependent NADase induction phenotype. These results suggest that CovS is related to the phenotype in SpeB independent manner.
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Affiliation(s)
- Ichiro Tatsuno
- Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, Japan
| | - Masanori Isaka
- Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, Japan
| | - Tadao Hasegawa
- Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, Japan
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4
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Schiavolin L, Deneubourg G, Steinmetz J, Smeesters PR, Botteaux A. Group A Streptococcus adaptation to diverse niches: lessons from transcriptomic studies. Crit Rev Microbiol 2024; 50:241-265. [PMID: 38140809 DOI: 10.1080/1040841x.2023.2294905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 12/10/2023] [Indexed: 12/24/2023]
Abstract
Group A Streptococcus (GAS) is a major human pathogen, causing diseases ranging from mild superficial infections of the skin and pharyngeal epithelium to severe systemic and invasive diseases. Moreover, post infection auto-immune sequelae arise by a yet not fully understood mechanism. The ability of GAS to cause a wide variety of infections is linked to the expression of a large set of virulence factors and their transcriptional regulation in response to various physiological environments. The use of transcriptomics, among others -omics technologies, in addition to traditional molecular methods, has led to a better understanding of GAS pathogenesis and host adaptation mechanisms. This review focusing on bacterial transcriptomic provides new insight into gene-expression patterns in vitro, ex vivo and in vivo with an emphasis on metabolic shifts, virulence genes expression and transcriptional regulators role.
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Affiliation(s)
- Lionel Schiavolin
- Microbiology Laboratory, European Plotkin Institute of Vaccinology, Université libre de Bruxelles, Brussels, Belgium
| | - Geoffrey Deneubourg
- Microbiology Laboratory, European Plotkin Institute of Vaccinology, Université libre de Bruxelles, Brussels, Belgium
| | - Jenny Steinmetz
- Microbiology Laboratory, European Plotkin Institute of Vaccinology, Université libre de Bruxelles, Brussels, Belgium
| | - Pierre R Smeesters
- Microbiology Laboratory, European Plotkin Institute of Vaccinology, Université libre de Bruxelles, Brussels, Belgium
- Department of Paediatrics, Brussels University Hospital, Academic Children Hospital Queen Fabiola, Université libre de Bruxelles, Brussels, Belgium
| | - Anne Botteaux
- Microbiology Laboratory, European Plotkin Institute of Vaccinology, Université libre de Bruxelles, Brussels, Belgium
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5
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Herrera AL, Potts R, Huber VC, Chaussee MS. Influenza enhances host susceptibility to non-pulmonary invasive Streptococcus pyogenes infections. Virulence 2023; 14:2265063. [PMID: 37772916 PMCID: PMC10566429 DOI: 10.1080/21505594.2023.2265063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 09/25/2023] [Indexed: 09/30/2023] Open
Abstract
Streptococcus pyogenes (group A streptococcus; GAS) causes a variety of invasive diseases (iGAS) such as bacteremia, toxic shock syndrome, and pneumonia, which are associated with high mortality despite the susceptibility of the bacteria to penicillin ex vivo. Epidemiologic studies indicate that respiratory influenza virus infection is associated with an increase in the frequency of iGAS diseases, including those not directly involving the lung. We modified a murine model of influenza A (IAV)-GAS superinfection to determine if viral pneumonia increased the susceptibility of mice subsequently infected with GAS in the peritoneum. The results showed that respiratory IAV infection increased the morbidity (weight loss) of mice infected intraperitoneally (i.p.) with GAS 3, 5, and 10 d after the initial viral infection. Mortality was also significantly increased when mice were infected with GAS 3 and 5 d after pulmonary IAV infection. Increased mortality among mice infected with virus 5 d prior to bacterial infection correlated with increased dissemination of GAS from the peritoneum to the blood, spleen, and lungs. The interval was also associated with a significant increase in the pro-inflammatory cytokines IFN-γ, IL-12, TNF-α, MCP-1 and IL-27 in sera. We conclude, using a murine model, that respiratory influenza virus infection increases the likelihood and severity of systemic iGAS disease, even when GAS infection does not originate in the respiratory tract.
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Affiliation(s)
- Andrea L. Herrera
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, SD, USA
| | - Rashaun Potts
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, SD, USA
| | - Victor C. Huber
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, SD, USA
| | - Michael S. Chaussee
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, SD, USA
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6
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Rafiei V, Vélëz H, Piombo E, Dubey M, Tzelepis G. Verticillium longisporum phospholipase VlsPLA 2 is a virulence factor that targets host nuclei and modulates plant immunity. MOLECULAR PLANT PATHOLOGY 2023; 24:1078-1092. [PMID: 37171182 PMCID: PMC10423322 DOI: 10.1111/mpp.13352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 04/13/2023] [Accepted: 04/25/2023] [Indexed: 05/13/2023]
Abstract
Phospholipase A2 (PLA2 ) is a lipolytic enzyme that hydrolyses phospholipids in the cell membrane. In the present study, we investigated the role of secreted PLA2 (VlsPLA2 ) in Verticillium longisporum, a fungal phytopathogen that mostly infects plants belonging to the Brassicaceae family, causing severe annual yield loss worldwide. Expression of the VlsPLA2 gene, which encodes active PLA2 , is highly induced during the interaction of the fungus with the host plant Brassica napus. Heterologous expression of VlsPLA2 in Nicotiana benthamiana resulted in increased synthesis of certain phospholipids compared to plants in which enzymatically inactive PLA2 was expressed (VlsPLA2 ΔCD ). Moreover, VlsPLA2 suppresses the hypersensitive response triggered by the Cf4/Avr4 complex, thereby suppressing the chitin-induced reactive oxygen species burst. VlsPLA2 -overexpressing V. longisporum strains showed increased virulence in Arabidopsis plants, and transcriptomic analysis of this fungal strain revealed that the induction of the gene contributed to increased virulence. VlsPLA2 was initially localized to the host nucleus and then translocated to the chloroplasts at later time points. In addition, VlsPLA2 bound to the vesicle-associated membrane protein A (VAMPA) and was transported to the nuclear membrane. In the nucleus, VlsPLA2 caused major alterations in the expression levels of genes encoding transcription factors and subtilisin-like proteases, which play a role in plant immunity. In conclusion, our study showed that VlsPLA2 acts as a virulence factor, possibly by hydrolysing host nuclear envelope phospholipids, which, through a signal transduction cascade, may suppress basal plant immune responses.
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Affiliation(s)
- Vahideh Rafiei
- Department of Forest Mycology and Plant PathologySwedish University of Agricultural Sciences, Uppsala BiocenterUppsalaSweden
| | - Heriberto Vélëz
- Department of Forest Mycology and Plant PathologySwedish University of Agricultural Sciences, Uppsala BiocenterUppsalaSweden
| | - Edoardo Piombo
- Department of Forest Mycology and Plant PathologySwedish University of Agricultural Sciences, Uppsala BiocenterUppsalaSweden
| | - Mukesh Dubey
- Department of Forest Mycology and Plant PathologySwedish University of Agricultural Sciences, Uppsala BiocenterUppsalaSweden
| | - Georgios Tzelepis
- Department of Forest Mycology and Plant PathologySwedish University of Agricultural Sciences, Uppsala BiocenterUppsalaSweden
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7
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Zhou X, Song H, Pan F, Yuan C, Jia L, Wu B, Fan H, Ma Z. The dual M protein systems have diverse biological characteristics, but both contribute to M18-type Group A Streptococcus pathogenicity. Microbes Infect 2023:105209. [PMID: 37597608 DOI: 10.1016/j.micinf.2023.105209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 08/05/2023] [Accepted: 08/07/2023] [Indexed: 08/21/2023]
Abstract
M protein is a key surface virulence factor in Group A Streptococcus (GAS), Group C Streptococcus (GCS), and other streptococcal species. GAS encodes M protein using the emm gene, while GCS employs the szm (or sem) gene. In M18-type GAS, dual M protein systems exist, comprising both GAS and GCS M proteins (encoded separately by emm18 and spa18). The spa18 gene in M18-type GAS shares a conserved region highly similar to GCS's szm gene. Our study reveals that spa18 exhibits higher transcription levels than emm18 in M18-type GAS strains. The dual M protein systems defective mutant (Δemm18Δspa18) displays a smooth surface, whereas wild-type and single M protein gene mutants remain rough. M18 and SPA18 proteins possess distinct characteristics, showing varied binding properties and cytotoxicity effects on macrophages (THP-1) and keratinocytes (HaCaT). Both emm18 and spa18 genes contribute to the skin pathogenicity of M18-type GAS. Transcriptome analysis suggests the potential involvement of the mga gene in spa18 transcription regulation, while SpyM18_2047 appears to be specific to spa18 regulation. In summary, this research offers a crucial understanding of the biological characteristics of dual M protein systems in M18-type GAS, highlighting their contributions to virulence and transcriptional regulation.
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Affiliation(s)
- Xiaorui Zhou
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Ministry of Agriculture Key Laboratory of Animal Bacteriology, Nanjing 210095, China
| | - Haoshuai Song
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Ministry of Agriculture Key Laboratory of Animal Bacteriology, Nanjing 210095, China
| | - Fei Pan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Ministry of Agriculture Key Laboratory of Animal Bacteriology, Nanjing 210095, China
| | - Chen Yuan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Ministry of Agriculture Key Laboratory of Animal Bacteriology, Nanjing 210095, China
| | - Lu Jia
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Ministry of Agriculture Key Laboratory of Animal Bacteriology, Nanjing 210095, China
| | - Bing Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Ministry of Agriculture Key Laboratory of Animal Bacteriology, Nanjing 210095, China
| | - Hongjie Fan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Ministry of Agriculture Key Laboratory of Animal Bacteriology, Nanjing 210095, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Zhe Ma
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Ministry of Agriculture Key Laboratory of Animal Bacteriology, Nanjing 210095, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China.
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8
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Lei B, Hanks TS, Bao Y, Liu M. Slipped-strand mispairing within a polycytidine tract in transcriptional regulator mga leads to M protein phase variation and Mga length polymorphism in Group A Streptococcus. Front Microbiol 2023; 14:1212149. [PMID: 37434706 PMCID: PMC10330708 DOI: 10.3389/fmicb.2023.1212149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 06/06/2023] [Indexed: 07/13/2023] Open
Abstract
The M protein, a major virulence factor of Group A Streptococcus (GAS), is regulated by the multigene regulator Mga. An unexplained phenomena frequently occurring with in vitro genetic manipulation or culturing of M1T1 GAS strains is the loss of M protein production. This study was aimed at elucidating the basis for the loss of M protein production. The majority of M protein-negative (M-) variants had one C deletion at a tract of 8 cytidines starting at base 1,571 of the M1 mga gene, which is designated as c.1571C[8]. The C deletion led to a c.1571C[7] mga variant that has an open reading frame shift and encodes a Mga-M protein fusion protein. Transformation with a plasmid containing wild-type mga restored the production of the M protein in the c.1571C[7] mga variant. Isolates producing M protein (M+) were recovered following growth of the c.1571C[7] M protein-negative variant subcutaneously in mice. The majority of the recovered isolates with reestablished M protein production had reverted back from c.1571C[7] to c.1571C[8] tract and some M+ isolates lost another C in the c.1571C[7] tract, leading to a c.1571C[6] variant that encodes a functional Mga with 13 extra amino acid residues at the C-terminus compared with wild-type Mga. The nonfunctional c.1571C[7] and functional c.1571C[6] variants are present in M1, M12, M14, and M23 strains in NCBI genome databases, and a G-to-A nonsense mutation at base 1,657 of M12 c.1574C[7] mga leads to a functional c.1574C[7]/1657A mga variant and is common in clinical M12 isolates. The numbers of the C repeats in this polycytidine tract and the polymorphism at base 1,657 lead to polymorphism in the size of Mga among clinical isolates. These findings demonstrate the slipped-strand mispairing within the c.1574C[8] tract of mga as a reversible switch controlling M protein production phase variation in multiple GAS common M types.
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Affiliation(s)
- Benfang Lei
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, United States
| | - Tracey S. Hanks
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, United States
| | - Yunjuan Bao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Mengyao Liu
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, United States
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9
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Banerji R, Saroj SD. Exposure to Acyl Homoserine Lactone Enhances Survival of Streptococcus pyogenes in Murine Macrophages. MICROBIAL ECOLOGY 2022; 84:1256-1263. [PMID: 34782937 DOI: 10.1007/s00248-021-01926-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 11/09/2021] [Indexed: 06/13/2023]
Abstract
Streptococcus pyogenes is an opportunistic pathogen causing infections of the skin and upper respiratory tract of the human host. Due to the polymicrobial community present in the human host, S. pyogenes comes across several interspecies signalling molecules. Among these molecules, N-(3-oxododecanoyl)-L-homoserine lactone (Oxo-C12) modulates the morphology, thereby enhancing virulence characteristics of S. pyogenes. After the initial attachment of the bacteria to the host cell, the pathogen needs to invade the host immune system for a successful infection to occur. The host immune system is activated upon infection, where macrophages engulf the pathogen, thereby killing the bacteria. However, S. pyogenes have evolved various strategies to evade the host immune response. In this study, we investigate the role of Oxo-C12 in enhancing the survival of S. pyogenes M3 in murine macrophages. The observed Oxo-C12-mediated increased survival in murine macrophages was through increased lysozyme and acid stress resistance. Moreover, Oxo-C12 increased the survival of S. pyogenes in normal human serum. Thus, understanding the role of interspecies signalling in enhancing the survival strategies of S. pyogenes in the host will further help fill the gap for therapeutics development.
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Affiliation(s)
- Rajashri Banerji
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Symbiosis Knowledge Village, Lavale, Pune, 412115, Maharashtra, India
| | - Sunil D Saroj
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Symbiosis Knowledge Village, Lavale, Pune, 412115, Maharashtra, India.
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10
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Characterization of M-Type-Specific Pilus Expression in Group A Streptococcus. J Bacteriol 2022; 204:e0027022. [PMID: 36286511 PMCID: PMC9664953 DOI: 10.1128/jb.00270-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Our ability to characterize how a pathogen infects and causes disease, and consequently our ability to devise approaches to prevent or attenuate such infections, is inhibited by the finding that isolates of a given pathogen often show phenotypic variability, for example, in their ability to adhere to host cells through modulation of cell surface adhesins. Such variability is observed between isolates of group A
Streptococcus
(GAS), and this study investigates the molecular basis for why some GAS isolates produce pili, cell wall-anchored adhesins, in lower abundance than other isolates do.
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11
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The Integrative Conjugative Element ICESpyM92 Contributes to Pathogenicity of Emergent Antimicrobial-Resistant emm92 Group A Streptococcus. Infect Immun 2022; 90:e0008022. [PMID: 35913172 PMCID: PMC9387263 DOI: 10.1128/iai.00080-22] [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: 02/03/2023] Open
Abstract
Antimicrobial resistance-encoding mobile genetic elements (MGEs) may contribute to the disease potential of bacterial pathogens. We previously described the association of Group A Streptococcus (GAS) derived from invasive disease with increasingly frequent antimicrobial resistance (AMR). We hypothesized that a 65-kb AMR-encoding MGE (ICESpyM92), highly conserved among closely related emergent invasive emm92 GAS, contributes to GAS disease potential. Here, we provide evidence that a combination of ICESpyM92- and core genome-dependent differential gene expression (DGE) contributes to invasive disease phenotypes of emergent emm92 GAS. Using isogenic ICESpyM92 mutants generated in distinct emm92 genomic backgrounds, we determined the presence of ICESpyM92 enhances GAS virulence in a mouse subcutaneous infection model. Measurement of in vitro and ex vivo DGE indicates ICESpyM92 influences GAS global gene expression in a background-dependent manner. Our study links virulence and AMR on a unique MGE via MGE-related DGE and highlights the importance of investigating associations between AMR-encoding MGEs and pathogenicity.
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Mu X, Wang Y, Sun L, Zhao S, Jin X, Zhang J, Yu Y, Wu X. Invasive Infection With emm3/ST15 Streptococcus pyogenes: The First Case Report From China and Complete Genome Analysis. Front Med (Lausanne) 2022; 9:861087. [PMID: 35615092 PMCID: PMC9126071 DOI: 10.3389/fmed.2022.861087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/31/2022] [Indexed: 11/24/2022] Open
Abstract
Streptococcus pyogenes (GAS) may cause severe invasive disease with a high fatality rate, especially M3-type strains, which are less common in China. Here, we report the first emm3/ST15 invasive GAS infection case in China. The patient was diagnosed with severe skin and soft tissue infection (SSTI) and septicaemia caused by one GAS strain. Antibiotic susceptibility tests showed that the isolate was susceptible to all tested drugs. Antimicrobial therapy was then applied, and the patient fully recovered and was discharged from the hospital on Day 43. Whole-genome sequencing was carried out using the Illumina and Oxford Nanopore platforms and revealed this to be the first emm3/ST15-type GAS invasive infection in China. The closely related emm3/ST15-type GAS strains are MGAS315 from the United States and M3-b from Japan. Our finding is a warning that we should pay attention to invasive M3-type GAS infections in China and indicates the global spread of the highly virulent emm3/ST15 GAS strain.
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Affiliation(s)
- Xinli Mu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Regional Medical Center for National Institute of Respiratory Diseases, Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Yanfei Wang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Regional Medical Center for National Institute of Respiratory Diseases, Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Lu Sun
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Regional Medical Center for National Institute of Respiratory Diseases, Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Shanshan Zhao
- Department of Clinical Laboratory, Shangyu People's Hospital, Shaoxing, China
| | - Xi Jin
- Centre of Laboratory Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Junli Zhang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Regional Medical Center for National Institute of Respiratory Diseases, Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Yunsong Yu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Regional Medical Center for National Institute of Respiratory Diseases, Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Xueqing Wu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Regional Medical Center for National Institute of Respiratory Diseases, Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
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Prevalence, Diversity and UV-Light Inducibility Potential of Prophages in Bacillus subtilis and Their Possible Roles in Host Properties. Viruses 2022; 14:v14030483. [PMID: 35336890 PMCID: PMC8951512 DOI: 10.3390/v14030483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 02/03/2022] [Accepted: 02/15/2022] [Indexed: 12/10/2022] Open
Abstract
Bacillus subtilis is an important bacterial species due to its various industrial, medicinal, and agricultural applications. Prophages are known to play vital roles in host properties. Nevertheless, studies on the prophages and temperate phages of B. subtilis are relatively limited. In the present study, an in silico analysis was carried out in sequenced B. subtilis strains to investigate their prevalence, diversity, insertion sites, and potential roles. In addition, the potential for UV induction and prevalence was investigated. The in silico prophage analysis of 164 genomes of B. subtilis strains revealed that 75.00% of them contained intact prophages that exist as integrated and/or plasmid forms. Comparative genomics revealed the rich diversity of the prophages distributed in 13 main clusters and four distinct singletons. The analysis of the putative prophage proteins indicated the involvement of prophages in encoding the proteins linked to the immunity, bacteriocin production, sporulation, arsenate, and arsenite resistance of the host, enhancing its adaptability to diverse environments. An induction study in 91 B. subtilis collections demonstrated that UV-light treatment was instrumental in producing infective phages in 18.68% of them, showing a wide range of host specificity. The high prevalence and inducibility potential of the prophages observed in this study implies that prophages may play vital roles in the B. subtilis host.
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Flores Ramos S, Brugger SD, Escapa IF, Skeete CA, Cotton SL, Eslami SM, Gao W, Bomar L, Tran TH, Jones DS, Minot S, Roberts RJ, Johnston CD, Lemon KP. Genomic Stability and Genetic Defense Systems in Dolosigranulum pigrum, a Candidate Beneficial Bacterium from the Human Microbiome. mSystems 2021; 6:e0042521. [PMID: 34546072 PMCID: PMC8547433 DOI: 10.1128/msystems.00425-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 08/27/2021] [Indexed: 01/05/2023] Open
Abstract
Dolosigranulum pigrum is positively associated with indicators of health in multiple epidemiological studies of human nasal microbiota. Knowledge of the basic biology of D. pigrum is a prerequisite for evaluating its potential for future therapeutic use; however, such data are very limited. To gain insight into D. pigrum's chromosomal structure, pangenome, and genomic stability, we compared the genomes of 28 D. pigrum strains that were collected across 20 years. Phylogenomic analysis showed closely related strains circulating over this period and closure of 19 genomes revealed highly conserved chromosomal synteny. Gene clusters involved in the mobilome and in defense against mobile genetic elements (MGEs) were enriched in the accessory genome versus the core genome. A systematic analysis for MGEs identified the first candidate D. pigrum prophage and insertion sequence. A systematic analysis for genetic elements that limit the spread of MGEs, including restriction modification (RM), CRISPR-Cas, and deity-named defense systems, revealed strain-level diversity in host defense systems that localized to specific genomic sites, including one RM system hot spot. Analysis of CRISPR spacers pointed to a wealth of MGEs against which D. pigrum defends itself. These results reveal a role for horizontal gene transfer and mobile genetic elements in strain diversification while highlighting that in D. pigrum this occurs within the context of a highly stable chromosomal organization protected by a variety of defense mechanisms. IMPORTANCE Dolosigranulum pigrum is a candidate beneficial bacterium with potential for future therapeutic use. This is based on its positive associations with characteristics of health in multiple studies of human nasal microbiota across the span of human life. For example, high levels of D. pigrum nasal colonization in adults predicts the absence of Staphylococcus aureus nasal colonization. Also, D. pigrum nasal colonization in young children is associated with healthy control groups in studies of middle ear infections. Our analysis of 28 genomes revealed a remarkable stability of D. pigrum strains colonizing people in the United States across a 20-year span. We subsequently identified factors that can influence this stability, including genomic stability, phage predators, the role of MGEs in strain-level variation, and defenses against MGEs. Finally, these D. pigrum strains also lacked predicted virulence factors. Overall, these findings add additional support to the potential for D. pigrum as a therapeutic bacterium.
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Affiliation(s)
| | - Silvio D. Brugger
- The Forsyth Institute (Microbiology), Cambridge, Massachusetts, USA
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA
| | - Isabel Fernandez Escapa
- The Forsyth Institute (Microbiology), Cambridge, Massachusetts, USA
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA
- Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | | | - Sean L. Cotton
- The Forsyth Institute (Microbiology), Cambridge, Massachusetts, USA
| | - Sara M. Eslami
- The Forsyth Institute (Microbiology), Cambridge, Massachusetts, USA
| | - Wei Gao
- The Forsyth Institute (Microbiology), Cambridge, Massachusetts, USA
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA
| | - Lindsey Bomar
- The Forsyth Institute (Microbiology), Cambridge, Massachusetts, USA
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA
| | - Tommy H. Tran
- Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Dakota S. Jones
- Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Samuel Minot
- Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | | | - Christopher D. Johnston
- The Forsyth Institute (Microbiology), Cambridge, Massachusetts, USA
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts, USA
- Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Katherine P. Lemon
- The Forsyth Institute (Microbiology), Cambridge, Massachusetts, USA
- Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
- Division of Infectious Diseases, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Section of Infectious Diseases, Texas Children’s Hospital, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
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15
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Streptococcus pyogenes TrxSR Two-Component System Regulates Biofilm Production in Acidic Environments. Infect Immun 2021; 89:e0036021. [PMID: 34424754 DOI: 10.1128/iai.00360-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Bacteria form biofilms for their protection against environmental stress and produce virulence factors within the biofilm. Biofilm formation in acidified environments is regulated by a two-component system, as shown by studies on isogenic mutants of the sensor protein of the two-component regulatory system in Streptococcus pyogenes. In this study, we found that the LiaS histidine kinase sensor mediates biofilm production and pilus expression in an acidified environment through glucose fermentation. The liaS isogenic mutant produced biofilms in a culture acidified by hydrochloric acid but not glucose, suggesting that the acidified environment is sensed by another protein. In addition, the trxS isogenic mutant could not produce biofilms or activate the mga promoter in an acidified environment. Mass spectrometry analysis showed that TrxS regulates M protein, consistent with the transcriptional regulation of emm, which encodes M protein. Our results demonstrate that biofilm production during environmental acidification is directly under the control of TrxS.
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16
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Rutbeek NR, Rezasoltani H, Patel TR, Khajehpour M, Prehna G. Molecular mechanism of quorum sensing inhibition in Streptococcus by the phage protein paratox. J Biol Chem 2021; 297:100992. [PMID: 34298018 PMCID: PMC8383118 DOI: 10.1016/j.jbc.2021.100992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/15/2021] [Accepted: 07/19/2021] [Indexed: 11/25/2022] Open
Abstract
Streptococcus pyogenes, or Group A Streptococcus, is a Gram-positive bacterium that can be both a human commensal and a pathogen. Central to this dichotomy are temperate bacteriophages that incorporate into the bacterial genome as prophages. These genetic elements encode both the phage proteins and the toxins harmful to the human host. One such conserved phage protein, paratox (Prx), is always found encoded adjacent to the toxin genes, and this linkage is preserved during all stages of the phage life cycle. Within S. pyogenes, Prx functions to inhibit the quorum-sensing receptor-signal pair ComRS, the master regulator of natural competence, or the ability to uptake endogenous DNA. However, the mechanism by which Prx directly binds and inhibits the receptor ComR is unknown. To understand how Prx inhibits ComR at the molecular level, we pursued an X-ray crystal structure of Prx bound to ComR. The structural data supported by solution X-ray scattering data demonstrate that Prx induces a conformational change in ComR to directly access its DNA-binding domain. Furthermore, electromobility shift assays and competition binding assays reveal that Prx effectively uncouples the interdomain conformational change required for activation of ComR via the signaling molecule XIP. Although to our knowledge the molecular mechanism of quorum-sensing inhibition by Prx is unique, it is analogous to the mechanism employed by the phage protein Aqs1 in Pseudomonas aeruginosa. Together, this demonstrates an example of convergent evolution between Gram-positive and Gram-negative phages to inhibit quorum-sensing and highlights the versatility of small phage proteins.
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Affiliation(s)
- Nicole R Rutbeek
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Hanieh Rezasoltani
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Trushar R Patel
- Department of Chemistry and Biochemistry, University of Lethbridge, Alberta, Canada
| | - Mazdak Khajehpour
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Gerd Prehna
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.
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17
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Population Genomics of emm4 Group A Streptococcus Reveals Progressive Replacement with a Hypervirulent Clone in North America. mSystems 2021; 6:e0049521. [PMID: 34374563 PMCID: PMC8409732 DOI: 10.1128/msystems.00495-21] [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] [Indexed: 11/30/2022] Open
Abstract
Clonal replacement is a major driver for changes in bacterial disease epidemiology. Recently, it has been proposed that episodic emergence of novel, hypervirulent clones of group A Streptococcus (GAS) results from acquisition of a 36-kb DNA region leading to increased expression of the cytotoxins Nga (NADase) and SLO (streptolysin O). We previously described a gene fusion event involving the gene encoding the GAS M protein (emm) and an adjacent M-like protein (enn) in the emm4 GAS population, a GAS emm type that lacks the hyaluronic acid capsule. Using whole-genome sequencing of a temporally and geographically diverse set of 1,126 isolates, we discovered that the North American emm4 GAS population has undergone clonal replacement with emergent GAS strains completely replacing historical isolates by 2017. Emergent emm4 GAS strains contained a handful of small genetic variations, including the emm-enn gene fusion, and showed a marked in vitro growth defect compared to historical strains. In contrast to other previously described GAS clonal replacement events, emergent emm4 GAS strains were not defined by acquisition of exogenous DNA and had no significant increase in transcript levels of nga and slo toxin genes via RNA sequencing and quantitative real-time PCR analysis relative to historic strains. Despite the in vitro growth differences, emergent emm4 GAS strains were hypervirulent in mice and ex vivo growth in human blood compared to historical strains. Thus, these data detail the emergence and dissemination of a hypervirulent acapsular GAS clone defined by small, endogenous genetic variation, thereby defining a novel model for GAS strain replacement. IMPORTANCE Severe invasive infections caused by group A Streptococcus (GAS) result in substantial morbidity and mortality in children and adults worldwide. Previously, GAS clonal strain replacement has been attributed to acquisition of exogenous DNA leading to novel virulence gene acquisition or increased virulence gene expression. Our study of type emm4 GAS identified emergence of a hypervirulent GAS clade defined by variation in endogenous DNA content and lacking augmented toxin gene expression relative to replaced strains. These findings expand our understanding of the molecular mechanisms underlying bacterial clonal emergence.
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18
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Ge H, Xu Y, Hu M, Zhang K, Zhang S, Jiao X, Chen X. Isolation, Characterization, and Application in Poultry Products of a Salmonella-Specific Bacteriophage, S55. J Food Prot 2021; 84:1202-1212. [PMID: 33710342 DOI: 10.4315/jfp-20-438] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 03/08/2021] [Indexed: 12/14/2022]
Abstract
ABSTRACT Salmonellosis occurs frequently worldwide, causing serious threats to public health. The abuse of antibiotics is increasing antibiotic resistance in bacteria, thereby making the prevention and control of Salmonella more difficult. A phage can help control the spread of bacteria. In this study, the lytic phage S55, whose host bacterium is Salmonella Pullorum, was isolated from fecal samples obtained from poultry farms. This phage belongs to the Siphoviridae and has a polyhedral head and a retraction-free tail. S55 lysed most cells of Salmonella Pullorum (58 of 60 strains, 96.67%) and Salmonella Enteritidis (97 of 104 strains, 93.27%). One-step growth kinetics revealed that the latent period was 10 min, the burst period was 80 min, and the burst size was 40 PFU per cell. The optimal multiplicity of infection was 0.01, and the phage was able to survive at pH values of 4 to 11 and temperatures of 40 to 60°C for 60 min. Complete genome sequence analysis revealed that the S55 genome consists of 42,781 bp (50.28% GC content) and 58 open reading frames, including 25 frames with known or assumed functions without tRNA genes. S55 does not carry genes that encode virulence or resistance factors. At 4 and 25°C, S55 reduced the populations of Salmonella Pullorum and Salmonella Enteritidis on chicken skin surfaces. S55 may be useful as a biological agent for the prevention and control of Salmonella infections. HIGHLIGHTS
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Affiliation(s)
- Haojie Ge
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, and Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou 225009, People's Republic of China
| | - Yanping Xu
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, and Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou 225009, People's Republic of China
| | - Maozhi Hu
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, and Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou 225009, People's Republic of China
| | - Kai Zhang
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, and Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou 225009, People's Republic of China
| | - Shuxuan Zhang
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, and Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou 225009, People's Republic of China
| | - Xin'an Jiao
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, and Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou 225009, People's Republic of China
| | - Xiang Chen
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, and Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou 225009, People's Republic of China
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19
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Banerji R, Saroj SD. Interspecies signaling affects virulence related morphological characteristics of Streptococcus pyogenes M3. FEMS Microbiol Lett 2021; 368:6307514. [PMID: 34156082 DOI: 10.1093/femsle/fnab079] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/18/2021] [Indexed: 01/03/2023] Open
Abstract
Streptococcus pyogenes is a Gram-positive human-specific pathogen that asymptomatically colonizes the human respiratory tract. The factors affecting the colonization to the host is not clearly understood. Adherence of the pathogen to host epithelial cell is the initial step for a successful colonization process. In the host, bacteria live in a polymicrobial community; thus, the signaling mediated between the bacteria plays a significant role in the colonization of the pathogen to the host. Thus, the effect of acyl-homoserine lactone, secreted by Gram-negative bacteria on the adhesion properties of S. pyogenes M3 strain was examined. N-(3-Oxododecanoyl)-L-homoserine lactone (Oxo-C12) increased the cell size as well as hydrophobicity of S. pyogenes. qPCR data revealed that the expression of sagA and hasA was negatively affected by Oxo-C12. Moreover, Oxo-C12 leads to changes in the morphological characteristic of S. pyogenes, further promoting adherence to host epithelia and biofilm formation on abiotic surface. The study demonstrates the role of Oxo-C12 as a factor that can promote virulence in S. pyogenes M3.
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Affiliation(s)
- Rajashri Banerji
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Symbiosis Knowledge Village, Lavale, Pune 412115, Maharashtra, India
| | - Sunil D Saroj
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Symbiosis Knowledge Village, Lavale, Pune 412115, Maharashtra, India
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20
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Streptococcus pyogenes ("Group A Streptococcus"), a Highly Adapted Human Pathogen-Potential Implications of Its Virulence Regulation for Epidemiology and Disease Management. Pathogens 2021; 10:pathogens10060776. [PMID: 34205500 PMCID: PMC8234341 DOI: 10.3390/pathogens10060776] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/02/2021] [Accepted: 06/17/2021] [Indexed: 11/16/2022] Open
Abstract
Streptococcus pyogenes (group A streptococci; GAS) is an exclusively human pathogen. It causes a variety of suppurative and non-suppurative diseases in people of all ages worldwide. Not all can be successfully treated with antibiotics. A licensed vaccine, in spite of its global importance, is not yet available. GAS express an arsenal of virulence factors responsible for pathological immune reactions. The transcription of all these virulence factors is under the control of three types of virulence-related regulators: (i) two-component systems (TCS), (ii) stand-alone regulators, and (iii) non-coding RNAs. This review summarizes major TCS and stand-alone transcriptional regulatory systems, which are directly associated with virulence control. It is suggested that this treasure of knowledge on the genetics of virulence regulation should be better harnessed for new therapies and prevention methods for GAS infections, thereby changing its global epidemiology for the better.
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21
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The Potential of Phage Therapy against the Emerging Opportunistic Pathogen Stenotrophomonas maltophilia. Viruses 2021; 13:v13061057. [PMID: 34204897 PMCID: PMC8228603 DOI: 10.3390/v13061057] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 05/28/2021] [Accepted: 05/31/2021] [Indexed: 12/22/2022] Open
Abstract
The isolation and characterization of bacteriophages for the treatment of infections caused by the multidrug resistant pathogen Stenotrophomonas maltophilia is imperative as nosocomial and community-acquired infections are rapidly increasing in prevalence. This increase is largely due to the numerous virulence factors and antimicrobial resistance genes encoded by this bacterium. Research on S. maltophilia phages to date has focused on the isolation and in vitro characterization of novel phages, often including genomic characterization, from the environment or by induction from bacterial strains. This review summarizes the clinical significance, virulence factors, and antimicrobial resistance mechanisms of S. maltophilia, as well as all phages isolated and characterized to date and strategies for their use. We further address the limited in vivo phage therapy studies conducted against this bacterium and discuss the future research needed to spearhead phages as an alternative treatment option against multidrug resistant S. maltophilia.
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22
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Gammoh NZ, Rink L. Closed-Tube Multiplex Real-Time PCR for the Detection of Group A Streptococcal Superantigens. Methods Mol Biol 2021; 2136:17-23. [PMID: 32430810 DOI: 10.1007/978-1-0716-0467-0_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Conventional PCR techniques are laborious and usually not suited for fast screening of large sample numbers in a clinical or research setting. Using this closed-tube multiplex real-time PCR, the presence of all 11 Streptococcus pyogenes superantigen (SAg) genes can be rapidly and accurately characterized. Identifying whether a strain contains a SAg can be done within 4 h compared to conventional methods which would take 11 times as long. This method provides an excellent diagnostic tool as well as a screening tool to help researchers clarify the role of SAgs in S. pyogenes infections.
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Affiliation(s)
- Nour Zahi Gammoh
- Institute of Immunology, Faculty of Medicine, RWTH Aachen University, University Hospital, Aachen, Germany
| | - Lothar Rink
- Institute of Immunology, Faculty of Medicine, RWTH Aachen University, University Hospital, Aachen, Germany.
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23
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Lichvariková A, Soltys K, Szemes T, Slobodnikova L, Bukovska G, Turna J, Drahovska H. Characterization of Clinical and Carrier Streptococcus agalactiae and Prophage Contribution to the Strain Variability. Viruses 2020; 12:v12111323. [PMID: 33217933 PMCID: PMC7698700 DOI: 10.3390/v12111323] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 11/14/2020] [Accepted: 11/16/2020] [Indexed: 12/13/2022] Open
Abstract
Streptococcus agalactiae (group B Streptococcus, GBS) represents a leading cause of invasive bacterial infections in newborns and is also responsible for diseases in older and immunocompromised adults. Prophages represent an important factor contributing to the genome plasticity and evolution of new strains. In the present study, prophage content was analyzed in human GBS isolates. Thirty-seven prophages were identified in genomes of 20 representative sequenced strains. On the basis of the sequence comparison, we divided the prophages into eight groups named A–H. This division also corresponded to the clustering of phage integrase, even though several different integration sites were observed in some relative prophages. Next, PCR method was used for detection of the prophages in 123 GBS strains from adult hospitalized patients and from pregnancy screening. At least one prophage was present in 105 isolates (85%). The highest prevalence was observed for prophage group A (71%) and satellite prophage group B (62%). Other groups were detected infrequently (1–6%). Prophage distribution did not differ between clinical and screening strains, but it was unevenly distributed in MLST (multi locus sequence typing) sequence types. High content of full-length and satellite prophages detected in present study implies that prophages could be beneficial for the host bacterium and could contribute to evolution of more adapted strains.
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Affiliation(s)
- Aneta Lichvariková
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovicova 6, 841 15 Bratislava, Slovakia; (A.L.); (K.S.); (T.S.); (J.T.)
- Comenius University Science Park, Ilkovicova 8, 841 04 Bratislava, Slovakia
| | - Katarina Soltys
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovicova 6, 841 15 Bratislava, Slovakia; (A.L.); (K.S.); (T.S.); (J.T.)
- Department of Microbiology and Virology, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovicova 6, 841 15 Bratislava, Slovakia
| | - Tomas Szemes
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovicova 6, 841 15 Bratislava, Slovakia; (A.L.); (K.S.); (T.S.); (J.T.)
- Comenius University Science Park, Ilkovicova 8, 841 04 Bratislava, Slovakia
| | - Livia Slobodnikova
- Institute of Microbiology, Medical Faculty, Comenius University in Bratislava, 813 72 Bratislava, Slovakia;
| | - Gabriela Bukovska
- Institute of Molecular Biology, Slovak Academy of Sciences, 840 05 Bratislava, Slovakia;
| | - Jan Turna
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovicova 6, 841 15 Bratislava, Slovakia; (A.L.); (K.S.); (T.S.); (J.T.)
| | - Hana Drahovska
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovicova 6, 841 15 Bratislava, Slovakia; (A.L.); (K.S.); (T.S.); (J.T.)
- Correspondence:
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24
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Salvà-Serra F, Jaén-Luchoro D, Jakobsson HE, Gonzales-Siles L, Karlsson R, Busquets A, Gomila M, Bennasar-Figueras A, Russell JE, Fazal MA, Alexander S, Moore ERB. Complete genome sequences of Streptococcus pyogenes type strain reveal 100%-match between PacBio-solo and Illumina-Oxford Nanopore hybrid assemblies. Sci Rep 2020; 10:11656. [PMID: 32669560 PMCID: PMC7363880 DOI: 10.1038/s41598-020-68249-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 06/16/2020] [Indexed: 01/23/2023] Open
Abstract
We present the first complete, closed genome sequences of Streptococcus pyogenes strains NCTC 8198T and CCUG 4207T, the type strain of the type species of the genus Streptococcus and an important human pathogen that causes a wide range of infectious diseases. S. pyogenes NCTC 8198T and CCUG 4207T are derived from deposit of the same strain at two different culture collections. NCTC 8198T was sequenced, using a PacBio platform; the genome sequence was assembled de novo, using HGAP. CCUG 4207T was sequenced and a de novo hybrid assembly was generated, using SPAdes, combining Illumina and Oxford Nanopore sequence reads. Both strategies yielded closed genome sequences of 1,914,862 bp, identical in length and sequence identity. Combining short-read Illumina and long-read Oxford Nanopore sequence data circumvented the expected error rate of the nanopore sequencing technology, producing a genome sequence indistinguishable to the one determined with PacBio. Sequence analyses revealed five prophage regions, a CRISPR-Cas system, numerous virulence factors and no relevant antibiotic resistance genes. These two complete genome sequences of the type strain of S. pyogenes will effectively serve as valuable taxonomic and genomic references for infectious disease diagnostics, as well as references for future studies and applications within the genus Streptococcus.
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Affiliation(s)
- Francisco Salvà-Serra
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, 413 46, Gothenburg, Sweden.
- Culture Collection University of Gothenburg (CCUG), Sahlgrenska Academy, University of Gothenburg, 413 46, Gothenburg, Sweden.
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, 413 46, Gothenburg, Sweden.
- Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, 413 46, Gothenburg, Sweden.
- Microbiology, Department of Biology, University of the Balearic Islands, 07122, Palma, Spain.
| | - Daniel Jaén-Luchoro
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, 413 46, Gothenburg, Sweden
- Culture Collection University of Gothenburg (CCUG), Sahlgrenska Academy, University of Gothenburg, 413 46, Gothenburg, Sweden
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, 413 46, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, 413 46, Gothenburg, Sweden
| | - Hedvig E Jakobsson
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, 413 46, Gothenburg, Sweden
- Culture Collection University of Gothenburg (CCUG), Sahlgrenska Academy, University of Gothenburg, 413 46, Gothenburg, Sweden
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, 413 46, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, 413 46, Gothenburg, Sweden
| | - Lucia Gonzales-Siles
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, 413 46, Gothenburg, Sweden
- Culture Collection University of Gothenburg (CCUG), Sahlgrenska Academy, University of Gothenburg, 413 46, Gothenburg, Sweden
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, 413 46, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, 413 46, Gothenburg, Sweden
| | - Roger Karlsson
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, 413 46, Gothenburg, Sweden
- Culture Collection University of Gothenburg (CCUG), Sahlgrenska Academy, University of Gothenburg, 413 46, Gothenburg, Sweden
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, 413 46, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, 413 46, Gothenburg, Sweden
- Nanoxis Consulting AB, 400 16, Gothenburg, Sweden
| | - Antonio Busquets
- Microbiology, Department of Biology, University of the Balearic Islands, 07122, Palma, Spain
| | - Margarita Gomila
- Microbiology, Department of Biology, University of the Balearic Islands, 07122, Palma, Spain
| | | | - Julie E Russell
- National Collection of Type Cultures (NCTC), Public Health England, London, NW9 5EQ, UK
| | - Mohammed Abbas Fazal
- National Collection of Type Cultures (NCTC), Public Health England, London, NW9 5EQ, UK
| | - Sarah Alexander
- National Collection of Type Cultures (NCTC), Public Health England, London, NW9 5EQ, UK
| | - Edward R B Moore
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, 413 46, Gothenburg, Sweden
- Culture Collection University of Gothenburg (CCUG), Sahlgrenska Academy, University of Gothenburg, 413 46, Gothenburg, Sweden
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, 413 46, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, 413 46, Gothenburg, Sweden
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25
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Prevalence and Characterization ofStreptococcus pyogenesClinical Isolates from Different Hospitals and Clinics in Mansoura. Int J Microbiol 2020. [DOI: 10.1155/2020/5814945] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Streptococcus pyogenesare associated with many bacterial diseases in both humans and animals and are capable of causing a multitude of human diseases.S. pyogenesisolates were identified by their bacitracin sensitivity, positivespy1258detection, and positive GAS latex agglutination. Different isolates were typed serotypically and genotypically by BOX-PCR. Different virulence factors were identified inS. pyogenesisolates. In addition, antimicrobial resistance was tested to eleven different antibiotics. Furthermore, the resistance mechanisms were determined phenotypically by the disc diffusion method. Finally, the correlation between both molecular and serotypes identified and the profile of virulence factors and clinical and geographical sources was determined for all isolates. Thirty-eightS. pyogenesisolates were collected from different clinical sources. Resistance testing indicated high resistance to mostly used antibiotics except amoxicillin/clavulanic acid, amoxicillin, and ampicillin. Serotyping results indicated five different serotypes, M1, M2, M3, M4, and M6, inS. pyogenesisolates, while six isolates were identified as untypeable. In addition, positive PCR results identified most of the tested SAgs genes in whichspeJgene was mostly identified followed byspeI, speC,andssagenes being identified in 81.6%, 63.3%, 60.5%, and 60.5%, respectively. However,speHwas the least detected. In contrast,speL, speM, andsmeZgenes could not be detected in all tested isolates. Finally, BOX-PCR molecular typing was a more effective clustering method when compared to the serotyping method in allS. pyogenes.In conclusion, the isolates in this study were highly resistant to mostly used antibiotics. M1 was the most identified serotype. No significant association was found between serotypes, BOX-PCR cluster groups, and SAgs genes profiles. However, by the application of BOX-PCR, effective molecular typing was obtained.
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26
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Abril AG, Carrera M, Böhme K, Barros-Velázquez J, Cañas B, Rama JLR, Villa TG, Calo-Mata P. Characterization of Bacteriophage Peptides of Pathogenic Streptococcus by LC-ESI-MS/MS: Bacteriophage Phylogenomics and Their Relationship to Their Host. Front Microbiol 2020; 11:1241. [PMID: 32582130 PMCID: PMC7296060 DOI: 10.3389/fmicb.2020.01241] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 05/14/2020] [Indexed: 01/21/2023] Open
Abstract
The present work focuses on LC-ESI-MS/MS (liquid chromatography-electrospray ionization-tandem mass spectrometry) analysis of phage-origin tryptic digestion peptides from mastitis-causing Streptococcus spp. isolated from milk. A total of 2,546 non-redundant peptides belonging to 1,890 proteins were identified and analyzed. Among them, 65 phage-origin peptides were determined as specific Streptococcus spp. peptides. These peptides belong to proteins such as phage repressors, phage endopeptidases, structural phage proteins, and uncharacterized phage proteins. Studies involving bacteriophage phylogeny and the relationship between phages encoding the peptides determined and the bacteria they infect were also performed. The results show how specific peptides are present in closely related phages, and a link exists between bacteriophage phylogeny and the Streptococcus spp. they infect. Moreover, the phage peptide M∗ATNLGQAYVQIM∗PSAK is unique and specific for Streptococcus agalactiae. These results revealed that diagnostic peptides, among others, could be useful for the identification and characterization of mastitis-causing Streptococcus spp., particularly peptides that belong to specific functional proteins, such as phage-origin proteins, because of their specificity to bacterial hosts.
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Affiliation(s)
- Ana G. Abril
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Mónica Carrera
- Department of Food Technology, Spanish National Research Council, Marine Research Institute, Vigo, Spain
| | - Karola Böhme
- Agroalimentary Technological Center of Lugo, Lugo, Spain
| | - Jorge Barros-Velázquez
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences, University of Santiago de Compostela, Lugo, Spain
| | - Benito Cañas
- Department of Analytical Chemistry, Complutense University of Madrid, Madrid, Spain
| | - Jose L. R. Rama
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Tomás G. Villa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Pilar Calo-Mata
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences, University of Santiago de Compostela, Lugo, Spain
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27
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Qiu C, Yuan Y, Lee SW, Ploplis VA, Castellino FJ. A local α-helix drives structural evolution of streptococcal M-protein affinity for host human plasminogen. Biochem J 2020; 477:1613-1630. [PMID: 32270857 PMCID: PMC7663350 DOI: 10.1042/bcj20200197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/07/2020] [Accepted: 04/08/2020] [Indexed: 11/17/2022]
Abstract
Plasminogen-binding group A streptococcal M-protein (PAM) is a signature surface virulence factor of specific strains of Group A Streptococcus pyogenes (GAS) and is an important tight binding protein for human plasminogen (hPg). After activation of PAM-bound hPg to the protease, plasmin (hPm), GAS cells develop invasive surfaces that are critical for their pathogenicity. PAMs are helical dimers in solution, which are sensitive to temperature changes over a physiological temperature range. We previously categorized PAMs into three classes (I-III) based on the number and nature of short tandem α-helical repeats (a1 and a2) in their NH2-terminal A-domains that dictate interactions with hPg/hPm. Class II PAMs are special cases since they only contain the a2-repeat, while Class I and Class III PAMs encompass complete a1a2-repeats. All dimeric PAMs tightly associate with hPg, regardless of their categories, but monomeric Class II PAMs bind to hPg much weaker than their Class I and Class III monomeric counterparts. Additionally, since the A-domains of Class II PAMs comprise different residues from other PAMs, the issue emerges as to whether Class II PAMs utilize different amino acid side chains for interactions with hPg. Herein, through NMR-refined structural analyses, we elucidate the atomic-level hPg-binding mechanisms adopted by two representative Class II PAMs. Furthermore, we develop an evolutionary model that explains from unique structural perspectives why PAMs develop variable A-domains with regard to hPg-binding affinity.
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Affiliation(s)
- Cunjia Qiu
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN 46556, U.S.A
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, U.S.A
| | - Yue Yuan
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN 46556, U.S.A
| | - Shaun W. Lee
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, U.S.A
| | - Victoria A. Ploplis
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN 46556, U.S.A
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, U.S.A
| | - Francis J. Castellino
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN 46556, U.S.A
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, U.S.A
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28
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Gilbert RA, Townsend EM, Crew KS, Hitch TCA, Friedersdorff JCA, Creevey CJ, Pope PB, Ouwerkerk D, Jameson E. Rumen Virus Populations: Technological Advances Enhancing Current Understanding. Front Microbiol 2020; 11:450. [PMID: 32273870 PMCID: PMC7113391 DOI: 10.3389/fmicb.2020.00450] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 03/02/2020] [Indexed: 01/07/2023] Open
Abstract
The rumen contains a multi-kingdom, commensal microbiome, including protozoa, bacteria, archaea, fungi and viruses, which enables ruminant herbivores to ferment and utilize plant feedstuffs that would be otherwise indigestible. Within the rumen, virus populations are diverse and highly abundant, often out-numbering the microbial populations that they both predate on and co-exist with. To date the research effort devoted to understanding rumen-associated viral populations has been considerably less than that given to the other microbial populations, yet their contribution to maintaining microbial population balance, intra-ruminal microbial lysis, fiber breakdown, nutrient cycling and genetic transfer may be highly significant. This review follows the technological advances which have contributed to our current understanding of rumen viruses and drawing on knowledge from other environmental and animal-associated microbiomes, describes the known and potential roles and impacts viruses have on rumen function and speculates on the future directions of rumen viral research.
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Affiliation(s)
- Rosalind A. Gilbert
- Department of Agriculture and Fisheries, Brisbane, QLD, Australia
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, QLD, Australia
| | - Eleanor M. Townsend
- Warwick Integrative Synthetic Biology Centre, School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Kathleen S. Crew
- Department of Agriculture and Fisheries, Brisbane, QLD, Australia
| | - Thomas C. A. Hitch
- Functional Microbiome Research Group, Institute of Medical Microbiology, RWTH University Hospital, Aachen, Germany
| | - Jessica C. A. Friedersdorff
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - Christopher J. Creevey
- Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Phillip B. Pope
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
- Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway
| | - Diane Ouwerkerk
- Department of Agriculture and Fisheries, Brisbane, QLD, Australia
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, QLD, Australia
| | - Eleanor Jameson
- Warwick Integrative Synthetic Biology Centre, School of Life Sciences, University of Warwick, Coventry, United Kingdom
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29
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MUSSER JAMESM. MOLECULAR MECHANISMS CONTRIBUTING TO FUZZY EPIDEMICS CAUSED BY GROUP A STREPTOCOCCUS, A FLESH-EATING HUMAN BACTERIAL PATHOGEN. TRANSACTIONS OF THE AMERICAN CLINICAL AND CLIMATOLOGICAL ASSOCIATION 2020; 131:356-368. [PMID: 32675873 PMCID: PMC7358509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Epidemics caused by microbial pathogens are inherently interesting because they can kill large numbers of our brethren, cause social upheaval, and alter history. Microbial epidemics will likely continue to occur at unpredictable times and result in poorly predictable consequences. Over a 30-year period, we have used the human bacterial pathogen group A streptococcus (also known as Streptococcus pyogenes) as a model organism to gain understanding of the molecular mechanisms contributing to epidemics caused by this pathogen and attendant virulence mechanisms. These epidemics have affected tens of millions of individuals worldwide and were largely unrecognized until revealed by full-genome sequence data from many thousands of isolates from intercontinental sources. Molecular genetic strategies, coupled with extensive use of relevant animal infection models, have delineated precise evolutionary genetic changes that contribute to pathogen clone emergence and successful dissemination among humans. Here, we summarize a few key findings from these studies.
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Affiliation(s)
- JAMES M. MUSSER
- Correspondence and reprint requests: James M. Musser, MD, PhD, Houston Methodist Research Institute, 6565 Fannin Street, Houston, TX 77030713-441-5890713-441-3886
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30
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Rezaei Javan R, Ramos-Sevillano E, Akter A, Brown J, Brueggemann AB. Prophages and satellite prophages are widespread in Streptococcus and may play a role in pneumococcal pathogenesis. Nat Commun 2019; 10:4852. [PMID: 31649284 PMCID: PMC6813308 DOI: 10.1038/s41467-019-12825-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 09/27/2019] [Indexed: 02/06/2023] Open
Abstract
Prophages (viral genomes integrated within a host bacterial genome) can confer various phenotypic traits to their hosts, such as enhanced pathogenicity. Here we analyse >1300 genomes of 70 different Streptococcus species and identify nearly 800 prophages and satellite prophages (prophages that do not encode their own structural components but rely on the bacterial host and another helper prophage for survival). We show that prophages and satellite prophages are widely distributed among streptococci in a structured manner, and constitute two distinct entities with little effective genetic exchange between them. Cross-species transmission of prophages is not uncommon. Furthermore, a satellite prophage is associated with virulence in a mouse model of Streptococcus pneumoniae infection. Our findings highlight the potential importance of prophages in streptococcal biology and pathogenesis. Prophages are viral genomes integrated within bacterial genomes. Here, Rezaei Javan et al. identify nearly 800 prophages and satellite prophages in > 1300 Streptococcus genomes, and show that a satellite prophage is associated with virulence in a mouse model of pneumococcal infection.
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Affiliation(s)
| | | | - Asma Akter
- Department of Medicine, Imperial College London, London, UK
| | - Jeremy Brown
- UCL Respiratory, Division of Medicine, University College London, London, UK
| | - Angela B Brueggemann
- Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Department of Medicine, Imperial College London, London, UK. .,Nuffield Department of Population Health, University of Oxford, Oxford, UK.
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31
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Coppens J, Xavier BB, Loens K, Lammens C, Ieven M, Matheeussen V, Goossens H, Malhotra-Kumar S. Remarkable Genome Stability among emm1 Group A Streptococcus in Belgium over 19 Years. Genome Biol Evol 2019; 11:1432-1439. [PMID: 31065672 PMCID: PMC6521816 DOI: 10.1093/gbe/evz093] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2019] [Indexed: 12/30/2022] Open
Abstract
During the last two decades, there has been a public health concern of severe invasive infections caused by Group A Streptococcus (GAS) of the emm1 genotype. This study investigated the dynamics of emm1 GAS during 1994–2013 in Belgium. emm1 GAS isolated from blood, tissue, and wounds of patients with invasive infections (n = 23, S1–S23), and from patients with uncomplicated pharyngitis (n = 15, NS1–NS15) were subjected to whole-genome mapping (WGM; kpn) (Opgen). Whole-genome sequencing was performed on 25 strains (WGS; S1–S23 and NS6–NS7) (Illumina Inc.). Belgian GAS belonged to the M1T1 clone typified by the 36-kb chromosomal region encoding extracellular toxins, NAD+-glycohydrolase and streptolysin O. Strains from 1994–1999 clustered together with published strains (MGAS5005 and M1476). From 2001 onward, invasive GAS showed higher genomic divergence in the accessory genome and harbored on average 7% prophage content. Low evolutionary rate (2.49E-008; P > 0.05) was observed in this study, indicating a highly stable genome. The studied invasive and pharyngitis isolates were no genetically distinct populations based on the WGM and core genome phylogeny analyses. Two copies of the speJ superantigen were present in the 1999 and 2010 study strains (n = 3), one being chromosomal and one being truncated and associated with phage remnants. This study showed that emm1 GAS in Belgium, compared with Canada and UK M1 strains, were highly conserved by harboring a remarkable genome stability over a 19-year period with variations observed in the accessory genome.
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Affiliation(s)
- Jasmine Coppens
- Laboratory of Medical Microbiology, Vaccine & Infectious Disease Institute, University of Antwerp, Belgium
| | - Basil Britto Xavier
- Laboratory of Medical Microbiology, Vaccine & Infectious Disease Institute, University of Antwerp, Belgium
| | - Katherine Loens
- Belgian Reference Centre for Group A Streptococcus, Antwerp University Hospital, Antwerp, Belgium
| | - Christine Lammens
- Laboratory of Medical Microbiology, Vaccine & Infectious Disease Institute, University of Antwerp, Belgium
| | - Margareta Ieven
- Laboratory of Medical Microbiology, Vaccine & Infectious Disease Institute, University of Antwerp, Belgium.,Belgian Reference Centre for Group A Streptococcus, Antwerp University Hospital, Antwerp, Belgium
| | - Veerle Matheeussen
- Belgian Reference Centre for Group A Streptococcus, Antwerp University Hospital, Antwerp, Belgium
| | - Herman Goossens
- Laboratory of Medical Microbiology, Vaccine & Infectious Disease Institute, University of Antwerp, Belgium.,Belgian Reference Centre for Group A Streptococcus, Antwerp University Hospital, Antwerp, Belgium
| | - Surbhi Malhotra-Kumar
- Laboratory of Medical Microbiology, Vaccine & Infectious Disease Institute, University of Antwerp, Belgium
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32
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van Dalen R, Fuchsberger FF, Rademacher C, van Strijp JAG, van Sorge NM. A Common Genetic Variation in Langerin (CD207) Compromises Cellular Uptake of Staphylococcus aureus. J Innate Immun 2019; 12:191-200. [PMID: 31141812 DOI: 10.1159/000500547] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/18/2019] [Indexed: 01/25/2023] Open
Abstract
Langerhans cells are key sentinel cells of the skin and mucosal lining. They sense microorganisms through their repertoire of pattern-recognition receptors to mount and direct appropriate immune responses. We recently demonstrated that human Langerhans cells interact with the Gram-positive pathogen Staphylococcus aureus through the Langerhans cell-specific receptor langerin (CD207). It was previously hypothesized that two linked single nucleotide polymorphisms (SNPs; N288D and K313I) in the carbohydrate recognition domain of langerin would affect interaction with microorganisms. We show that recognition of S. aureus by recombinant langerin molecules is abrogated in the co-inheriting SNP variant, which is mainly explained by the N288D SNP and further enhanced by K313I. Moreover, introduction of SNP N288D in ectopically-expressed langerin affected cellular distribution of the receptor such that langerin displayed enhanced plasma membraneexpression. Despite this increased binding of S. aureus by the langerin double SNP variant, uptake of bacteria by this langerin variant was compromised. Our findings indicate that in a proportion of the human population, the recognition and uptake of S. aureus by Langerhans cells may be affected, which could have important consequences for proper immune activation and S. aureus-associated disease.
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Affiliation(s)
- Rob van Dalen
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Felix F Fuchsberger
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Christoph Rademacher
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Jos A G van Strijp
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Nina M van Sorge
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands,
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33
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McShan WM, McCullor KA, Nguyen SV. The Bacteriophages of Streptococcus pyogenes. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0059-2018. [PMID: 31111820 PMCID: PMC11314938 DOI: 10.1128/microbiolspec.gpp3-0059-2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Indexed: 12/15/2022] Open
Abstract
The bacteriophages of Streptococcus pyogenes (group A streptococcus) play a key role in population shaping, genetic transfer, and virulence of this bacterial pathogen. Lytic phages like A25 can alter population distributions through elimination of susceptible serotypes but also serve as key mediators for genetic transfer of virulence genes and antibiotic resistance via generalized transduction. The sequencing of multiple S. pyogenes genomes has uncovered a large and diverse population of endogenous prophages that are vectors for toxins and other virulence factors and occupy multiple attachment sites in the bacterial genomes. Some of these sites for integration appear to have the potential to alter the bacterial phenotype through gene disruption. Remarkably, the phage-like chromosomal islands (SpyCI), which share many characteristics with endogenous prophages, have evolved to mediate a growth-dependent mutator phenotype while acting as global transcriptional regulators. The diverse population of prophages appears to share a large pool of genetic modules that promotes novel combinations that may help disseminate virulence factors to different subpopulations of S. pyogenes. The study of the bacteriophages of this pathogen, both lytic and lysogenic, will continue to be an important endeavor for our understanding of how S. pyogenes continues to be a significant cause of human disease.
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Affiliation(s)
- W Michael McShan
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73117
| | - Kimberly A McCullor
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73117
| | - Scott V Nguyen
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73117
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Wholey WY, Abu-Khdeir M, Yu EA, Siddiqui S, Esimai O, Dawid S. Characterization of the Competitive Pneumocin Peptides of Streptococcus pneumoniae. Front Cell Infect Microbiol 2019; 9:55. [PMID: 30915281 PMCID: PMC6422914 DOI: 10.3389/fcimb.2019.00055] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 02/20/2019] [Indexed: 01/01/2023] Open
Abstract
In the polymicrobial environment of the human nasopharynx, Streptococcus pneumoniae (pneumococcus) competes with other members of the microbial community for limited nutrients in part by secreting small peptide bacteriocins called pneumocins. Pneumocin production is controlled by a quorum sensing system encoded by the blp locus. Although the locus is found in all pneumococci, there is significant variability in the repertoire of pneumocins and associated immunity proteins encoded in the Bacteriocin Immunity Region (BIR) and in the presence or absence of a functional Blp transporter. Strains without an active Blp transporter are inactive in plate overlay assays and rely on a homologous transporter that is only produced during brief periods of competence to stimulate the blp locus and secrete pneumocins. The variability of the locus suggests that selective pressure is influencing the content to promote the optimal competitive environment. Much of the variability in the blp locus has been described at the genome level; the phenotypic activity attributable to the various BIR genes has not been fully described. To examine the role of the predicted pneumocin peptides in competition, 454 isolates were screened for competence independent blp pheromone secretion using plate assays. Active strains were characterized for inhibition, BIR content, BlpC pherotype and serotype. Deletion analysis on inhibitory strains demonstrated that BlpI and BlpJ peptides function as a two-peptide bacteriocin and that BlpIJ immunity is encoded by the co-transcribed blpU4/5 genes. BlpIJ secretion promotes inhibitory activity against the majority of pneumococcal isolates when expressed in a Blp transporter intact background. Intermediate levels of competition in biofilms were noted when BlpIJ containing strains carried the non-functional Blp transporter. Based on genome data, the combination of BlpIJ in a Blp transporter intact strain is surprisingly rare, despite clear advantages during colonization and biofilm growth. In contrast, we show that the blpK/pncF operon encoding the single-peptide pneumocin BlpK and its immunity protein is found in the majority of isolates. Unlike, BlpIJ and BlpK were shown to promote a limited spectrum of inhibition due in part to immunity that is independent of activation of the blp locus.
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Affiliation(s)
- Wei-Yun Wholey
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Maha Abu-Khdeir
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Emily A Yu
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Saher Siddiqui
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Ogenna Esimai
- Department of Computer Science and Engineering, University of Texas at Arlington, Arlington, TX, United States
| | - Suzanne Dawid
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI, United States.,Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, United States
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35
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Abstract
ABSTRACT
Streptococcus pyogenes
(i.e., the group A
Streptococcus
) is a human-restricted and versatile bacterial pathogen that produces an impressive arsenal of both surface-expressed and secreted virulence factors. Although surface-expressed virulence factors are clearly vital for colonization, establishing infection, and the development of disease, the secreted virulence factors are likely the major mediators of tissue damage and toxicity seen during active infection. The collective exotoxin arsenal of
S. pyogenes
is rivaled by few bacterial pathogens and includes extracellular enzymes, membrane active proteins, and a variety of toxins that specifically target both the innate and adaptive arms of the immune system, including the superantigens; however, despite their role in
S. pyogenes
disease, each of these virulence factors has likely evolved with humans in the context of asymptomatic colonization and transmission. In this article, we focus on the biology of the true secreted exotoxins of the group A
Streptococcus
, as well as their roles in the pathogenesis of human disease.
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Phylogenetic relationship of prophages is affected by CRISPR selection in Group A Streptococcus. BMC Microbiol 2019; 19:24. [PMID: 30691408 PMCID: PMC6348661 DOI: 10.1186/s12866-019-1393-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 01/14/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Group A Streptococcus (GAS) is a major human pathogen, which is associated with a wide spectrum of invasive diseases, such as pharyngitis, scarlet fever, rheumatic fever, and streptococcal toxic shock syndrome (STSS). It is hypothesized that differences in GAS pathogenicity are related to the acquisition of diverse bacteriophages (phages). Nevertheless, the GAS genome also harbors clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (cas) genes, which play an important role in eliminating foreign DNA, including those of phages. However, the structure of prophages in GAS strains is mosaic, and the phylogenetic relationship between prophages and CRISPR is not clear. In this study, we analyzed CRISPR and prophage structure using 118 complete genome sequences of GAS strains to elucidate the relationship between two genomic elements. Additionally, phylogenetic and M-type analyses were performed. RESULTS Of the 118 GAS strains, 80 harbored type I-C and/or II-A CRISPR/cas loci. A total of 553 spacer sequences were identified from CRISPR/cas loci and sorted into 229 patterns. We identified and classified 373 prophages into 14 groups. Some prophage groups shared a common integration site, and were related to M-type. We further investigated the correlation between spacer sequences and prophages. Of the 229 spacer sequence patterns, 203 were similar to that of other GAS prophages. No spacer showed similarity with that of a specific prophage group with mutL integration site. Moreover, the average number of prophages in strains with type II-A CRISPR was significantly less than that in type I-C CRISPR and non-CRISPR strains. However, there was no statistical difference between the average number of prophages in type I-C strains and that in non-CRISPR strains. CONCLUSIONS Our results indicated that type II-A CRISPR may play an important role in eliminating phages and that the prophage integration site may be an important criterion for the acceptance of foreign DNA by GAS. M type, spacer sequence, and prophage group data were correlated with the phylogenetic relationships of GAS. Therefore, we hypothesize that genetic characteristics and/or phylogenetic relationships of GAS may be estimated by analyzing its spacer sequences.
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Complete Genome Sequence of Hypervirulent Streptococcus pyogenes emm3 Strain 1838. Microbiol Resour Announc 2019; 8:MRA01494-18. [PMID: 30643894 PMCID: PMC6328667 DOI: 10.1128/mra.01494-18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 12/03/2018] [Indexed: 11/20/2022] Open
Abstract
We report the complete genome sequence for Streptococcus pyogenes strain 1838 (type emm3) isolated from a patient with toxic shock syndrome. The strain lacked the speK- and sla-encoding prophage frequently encountered among emm3 strains and possessed an Arg66His mutation in CovR of the 2-component virulence regulatory system CovRS.
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38
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Wessels MR. Capsular Polysaccharide of Group A Streptococcus. Microbiol Spectr 2019; 7:10.1128/microbiolspec.GPP3-0050-2018. [PMID: 30632480 PMCID: PMC6342470 DOI: 10.1128/microbiolspec.gpp3-0050-2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Indexed: 01/02/2023] Open
Abstract
Most clinical isolates of Streptococcus pyogenes elaborate a capsular polysaccharide, which is composed of hyaluronic acid, a high-molecular-mass polymer of alternating residues of N-acetyl glucosamine and glucuronic acid. Certain strains, particularly those of the M18 serotype, produce abundant amounts of capsule, resulting in formation of large, wet-appearing, translucent or "mucoid" colonies on solid media, whereas strains of M-types 4 and 22 produce none. Studies of acapsular mutant strains have provided evidence that the capsule enhances virulence in animal models of infection, an effect attributable, at least in part, to resistance to complement-mediated opsonophagocytic killing by leukocytes. The presence of the hyaluronic acid capsule may mask adhesins on the bacterial cell wall. However, the capsule itself can mediate bacterial attachment to host cells by binding to the hyaluronic-acid binding protein, CD44. Furthermore, binding of the S. pyogenes capsule to CD44 on host epithelial cells can trigger signaling events that disrupt cell-cell junctions and facilitate bacterial invasion into deep tissues. This article summarizes the biochemistry, genetics, regulation, and role in pathogenesis of this important virulence determinant.
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Affiliation(s)
- Michael R Wessels
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA
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39
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Abstract
Group A Streptococcus (GAS) causes common pharyngitis and skin infections and occasional severe invasive infections. This review describes the recent progress on the pathogenesis of hypervirulent GAS. CovRS mutations are frequent among invasive GAS isolates and lead to hypervirulence. GAS CovRS mutants can be selected in vivo by neutrophils. The role of protease SpeB in source-sink dynamics of wild-type GAS and hypervirulent variants is discussed. Streptolysin S and PAF acetylhydrolase Sse critically and synergistically contribute to the inhibition of neutrophil recruitment by GAS CovS mutants. CovS mutations in emm3 GAS lead to the vascular invasion and enhance systemic GAS dissemination.
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40
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Genomic Sequencing of High-Efficiency Transducing Streptococcal Bacteriophage A25: Consequences of Escape from Lysogeny. J Bacteriol 2018; 200:JB.00358-18. [PMID: 30224437 DOI: 10.1128/jb.00358-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/12/2018] [Indexed: 12/26/2022] Open
Abstract
Lytic bacteriophage A25, which infects Streptococcus pyogenes and several related species, has been used to better understand phage-microbe interactions due to its ability to mediate high-efficiency transduction. Most of these studies, however, are decades old and were conducted prior to the advent of next-generation sequencing and bioinformatics. The aim of our study was to gain a better understanding of the mechanism of high-efficiency transduction through analysis of the A25 genome. We show here that phage A25 is related to a family of genome prophages and became a lytic phage following escape from lysogeny. A lambdoid-like residual lysogeny module consisting of an operator site with two promoters and a cro-like antirepressor gene was identified, but the genes for the cI-like repressor and integrase are missing. Additionally, the genetic organization of the A25 genome was found to be modular in nature and similar to that of many prophages of S. pyogenes as well as from other streptococcal species. A study of A25 homology to all annotated prophages within S. pyogenes revealed near identity within the remnant lysogeny module of the A25 phage genome to the corresponding regions in resident prophages of genome strains MGAS10270 (M2), MGAS315 (M3), MGAS10570 (M4), and STAB902 (M4). Host range studies of MGAS10270, MGAS315, and MGAS10750 demonstrated that these strains were resistant to A25 infection. The resistance mechanism of superinfection immunity was confirmed experimentally through complementation of the operator region and cI-like repressor from prophage MGAS10270.2 into susceptible strains SF370, CEM1Δ4 (SF370ΔSpyCIM1), and ATCC 12204, which rendered all three strains resistant to A25 infection. In silico prediction of packaging through homology analysis of the terminase large subunit from bacteriophages within the known packaging mechanism of Gram-positive bacteria as well as the evidence of terminally redundant and/or circularly permuted sequences suggested that A25 grouped with phages employing the less stringent pac-type packaging mechanisms, which likely explains the characteristic A25 high-efficiency transduction capabilities. Only a few examples of lytic phages appearing following loss of part or all of the lysogeny module have been reported previously, and the genetic mosaicism of A25 suggests that this event may not have been a recent one. However, the discovery that this lytic bacteriophage shares some of the genetic pool of S. pyogenes prophages emphasizes the importance of genetic and biological characterization of bacteriophages when selecting phages for therapeutics or disinfectants, as phage-phage and phage-microbe interactions can be complex, requiring more than just assessment of host range and carriage of toxoid or virulence genes.IMPORTANCE Bacteriophages (bacterial viruses) play an important role in the shaping of bacterial populations as well as the dissemination of bacterial genetic material to new strains, resulting in the spread of virulence factors and antibiotic resistance genes. This study identified the genetic origins of Streptococcus pyogenes phage A25 and uncovered the molecular mechanism employed to promote horizontal transfer of DNA by transduction to new strains of this bacterium as well as identified the basis for its host range.
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41
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The conserved mosaic prophage protein paratox inhibits the natural competence regulator ComR in Streptococcus. Sci Rep 2018; 8:16535. [PMID: 30409983 PMCID: PMC6224593 DOI: 10.1038/s41598-018-34816-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 10/25/2018] [Indexed: 01/05/2023] Open
Abstract
Horizontal gene transfer is an important means of bacterial evolution. This includes natural genetic transformation, where bacterial cells become “competent” and DNA is acquired from the extracellular environment. Natural competence in many species of Streptococcus, is regulated by quorum sensing via the ComRS receptor-signal pair. The ComR-XIP (mature ComS peptide) complex induces expression of the alternative sigma factor SigX, which targets RNA polymerase to CIN-box promoters to activate genes involved in DNA uptake and recombination. In addition, the widely distributed Streptococcus prophage gene paratox (prx) also contains a CIN-box, and here we demonstrate it to be transcriptionally activated by XIP. In vitro experiments demonstrate that Prx binds ComR directly and prevents the ComR-XIP complex from interacting with DNA. Mutations of prx in vivo caused increased expression of the late competence gene ssb when induced with XIP as compared to wild-type, and Prx orthologues are able to inhibit ComR activation by XIP in a reporter strain which lacks an endogenous prx. Additionally, an X-ray crystal structure of Prx reveals a unique fold that implies a novel molecular mechanism to inhibit ComR. Overall, our results suggest Prx functions to inhibit the acquisition of new DNA by Streptococcus.
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42
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Chiang-Ni C, Shi YA, Lai CH, Chiu CH. Cytotoxicity and Survival Fitness of Invasive covS Mutant of Group A Streptococcus in Phagocytic Cells. Front Microbiol 2018; 9:2592. [PMID: 30425702 PMCID: PMC6218877 DOI: 10.3389/fmicb.2018.02592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 10/11/2018] [Indexed: 11/27/2022] Open
Abstract
Group A streptococci (GAS) with spontaneous mutations in the CovR/CovS regulatory system are more invasive and related to severe manifestations. GAS can replicate inside phagocytic cells; therefore, phagocytic cells could serve as the niche to select invasive covS mutants. Nonetheless, the encapsulated covS mutant is resistant to phagocytosis. The fate of intracellular covS mutant in phagocytic cells and whether the intracellular covS mutant contributes to invasive infections are unclear. In this study, capsule-deficient (cap-) strains were utilized to study how intracellular bacteria interacted with phagocytic cells. Results from the competitive infection model showed that the cap-covS mutant had better survival fitness than the cap- wild-type strain in the PMA-activated U937 cells. In addition, the cap-covS mutant caused more cell damages than the cap- wild-type strain and encapsulated covS mutant. Furthermore, treatments with infected cells with clindamycin to inhibit the intracellular bacteria growth was more effective to reduce bacterial toxicity than utilized penicillin to kill the extracellular bacteria. These results not only suggest that the covS mutant could be selected from the intracellular niche of phagocytic cells but also indicating that inactivating or killing intracellular GAS may be critical to prevent invasive infection.
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Affiliation(s)
- Chuan Chiang-Ni
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Yong-An Shi
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chih-Ho Lai
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Cheng-Hsun Chiu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan.,Department of Pediatrics, Chang Gung Children's Hospital, Taoyuan, Taiwan
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43
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RocA Has Serotype-Specific Gene Regulatory and Pathogenesis Activities in Serotype M28 Group A Streptococcus. Infect Immun 2018; 86:IAI.00467-18. [PMID: 30126898 DOI: 10.1128/iai.00467-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 08/13/2018] [Indexed: 12/21/2022] Open
Abstract
Serotype M28 group A streptococcus (GAS) is a common cause of infections such as pharyngitis ("strep throat") and necrotizing fasciitis ("flesh-eating" disease). Relatively little is known about the molecular mechanisms underpinning M28 GAS pathogenesis. Whole-genome sequencing studies of M28 GAS strains recovered from patients with invasive infections found an unexpectedly high number of missense (amino acid-changing) and nonsense (protein-truncating) polymorphisms in rocA (regulator of Cov), leading us to hypothesize that altered RocA activity contributes to M28 GAS molecular pathogenesis. To test this hypothesis, an isogenic rocA deletion mutant strain was created. Transcriptome sequencing (RNA-seq) analysis revealed that RocA inactivation significantly alters the level of transcripts for 427 and 323 genes at mid-exponential and early stationary growth phases, respectively, including genes for 41 transcription regulators and 21 virulence factors. In contrast, RocA transcriptomes from other GAS M protein serotypes are much smaller and include fewer transcription regulators. The rocA mutant strain had significantly increased secreted activity of multiple virulence factors and grew to significantly higher colony counts under acid stress in vitro RocA inactivation also significantly increased GAS virulence in a mouse model of necrotizing myositis. Our results demonstrate that RocA is an important regulator of transcription regulators and virulence factors in M28 GAS and raise the possibility that naturally occurring polymorphisms in rocA in some fashion contribute to human invasive infections caused by M28 GAS strains.
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44
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Overmann J, Huang S, Nübel U, Hahnke RL, Tindall BJ. Relevance of phenotypic information for the taxonomy of not-yet-cultured microorganisms. Syst Appl Microbiol 2018; 42:22-29. [PMID: 30197212 DOI: 10.1016/j.syapm.2018.08.009] [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: 04/29/2018] [Revised: 08/15/2018] [Accepted: 08/19/2018] [Indexed: 12/12/2022]
Abstract
To date, far less than 1% of the estimated global species of Bacteria and Archaea have been described and their names validly published. Aside from these quantitative limitations, our understanding of phenotypic and functional diversity of prokaryotes is also highly biased as not a single species has been described for 85 of the 118 phyla that are currently recognized. Due to recent advances in sequencing technology and capacity, metagenomic datasets accumulate at an increasing speed and new bacterial and archaeal genome sequences become available at a faster rate than newly described species. The growing gap between the diversity of Bacteria and Archaea held in pure culture and that detected by molecular methods has led to the proposal to establish a formal nomenclature for not-yet-cultured taxa primarily based on sequence information. According to this proposal, the concept of Candidatus species would be extended to groups of closely related genome sequences and their names validly published following established rules of bacterial nomenclature. The corresponding sequences would be deposited in public databases as the type. The suggested alterations of the International Code of Nomenclature of Prokaryotes raise concerns regarding (1) the reliability and stability of nomenclature, (2) the technological and conceptual limitations as well as availability of reference genomes, (3) the information content of in silico functional predictions, and (4) the recognition of evolutionary units of microbial diversity. These challenges need to be overcome to arrive at a meaningful taxonomy of not-yet-cultured prokaryotes with so far poorly understood phenotypes.
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Affiliation(s)
- Jörg Overmann
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, Inhoffenstraße 7B, 38124 Braunschweig, Germany; Deutsches Zentrum für Infektionsforschung (DZIF), Standort Braunschweig-Hannover, Braunschweig, Germany; German Center for Integrative Biodiversity Research (iDiv) Jena Halle Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany.
| | - Sixing Huang
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, Inhoffenstraße 7B, 38124 Braunschweig, Germany
| | - Ulrich Nübel
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, Inhoffenstraße 7B, 38124 Braunschweig, Germany; Deutsches Zentrum für Infektionsforschung (DZIF), Standort Braunschweig-Hannover, Braunschweig, Germany
| | - Richard L Hahnke
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, Inhoffenstraße 7B, 38124 Braunschweig, Germany
| | - Brian J Tindall
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, Inhoffenstraße 7B, 38124 Braunschweig, Germany
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45
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Lei B, Minor D, Feng W, Liu M. Hypervirulent Group A Streptococcus of Genotype emm3 Invades the Vascular System in Pulmonary Infection of Mice. Infect Immun 2018; 86:e00080-18. [PMID: 29610254 PMCID: PMC5964506 DOI: 10.1128/iai.00080-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 03/22/2018] [Indexed: 11/20/2022] Open
Abstract
Natural mutations of the two-component regulatory system CovRS are frequently associated with invasive group A Streptococcus (GAS) isolates and lead to the enhancement of virulence gene expression, innate immune evasion, systemic dissemination, and virulence. How CovRS mutations enhance systemic dissemination is not well understood. A hypervirulent GAS isolate of the emm3 genotype, MGAS315, was characterized using a mouse model of pulmonary infection to understand systemic dissemination. This strain has a G1370T mutation in the sensor kinase covS gene of CovRS. Intratracheal inoculation of MGAS315 led to the lung infection that displayed extensive Gram staining at the alveolar ducts, alveoli, and peribronchovascular and perivascular interstitium. The correction of the covS mutation did not alter the infection at the alveolar ducts and alveoli but prevented GAS invasion of the peribronchovascular and perivascular interstitium. Furthermore, the covS mutation allowed MGAS315 to disrupt and degrade the smooth muscle and endothelial layers of the blood vessels, directly contributing to systemic dissemination. It is concluded that hypervirulent emm3 GAS covS mutants can invade the perivascular interstitium and directly attack the vascular system for systemic dissemination.
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Affiliation(s)
- Benfang Lei
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, USA
| | - Dylan Minor
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, USA
| | - Wenchao Feng
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, USA
| | - Mengyao Liu
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, USA
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46
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Roszniowski B, McClean S, Drulis-Kawa Z. Burkholderia cenocepacia Prophages-Prevalence, Chromosome Location and Major Genes Involved. Viruses 2018; 10:v10060297. [PMID: 29857552 PMCID: PMC6024312 DOI: 10.3390/v10060297] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 05/28/2018] [Accepted: 05/29/2018] [Indexed: 12/21/2022] Open
Abstract
Burkholderia cenocepacia, is a Gram-negative opportunistic pathogen that belongs to Burkholderia cepacia complex (BCC) group. BCC representatives carry various pathogenicity factors and can infect humans and plants. Phages as bacterial viruses play a significant role in biodiversity and ecological balance in the environment. Specifically, horizontal gene transfer (HGT) and lysogenic conversion (temperate phages) influence microbial diversification and fitness. In this study, we describe the prevalence and gene content of prophages in 16 fully sequenced B. cenocepacia genomes stored in NCBI database. The analysis was conducted in silico by manual and automatic approaches. Sixty-three potential prophage regions were found and classified as intact, incomplete, questionable, and artifacts. The regions were investigated for the presence of known virulence factors, resulting in the location of sixteen potential pathogenicity mechanisms, including toxin–antitoxin systems (TA), Major Facilitator Superfamily (MFS) transporters and responsible for drug resistance. Investigation of the region’s closest neighborhood highlighted three groups of genes with the highest occurrence—tRNA-Arg, dehydrogenase family proteins, and ABC transporter substrate-binding proteins. Searches for antiphage systems such as BacteRiophage EXclusion (BREX) and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) in the analyzed strains suggested 10 sequence sets of CRISPR elements. Our results suggest that intact B. cenocepacia prophages may provide an evolutionary advantage to the bacterium, while domesticated prophages may help to maintain important genes.
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Affiliation(s)
- Bartosz Roszniowski
- Institute of Genetics and Microbiology, University of Wroclaw, 51-148 Wroclaw, Poland.
| | - Siobhán McClean
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Zuzanna Drulis-Kawa
- Institute of Genetics and Microbiology, University of Wroclaw, 51-148 Wroclaw, Poland.
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47
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Identification and Characterization of Serotype-Specific Variation in Group A Streptococcus Pilus Expression. Infect Immun 2018; 86:IAI.00792-17. [PMID: 29158432 DOI: 10.1128/iai.00792-17] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 11/13/2017] [Indexed: 12/22/2022] Open
Abstract
Isolates of a given bacterial pathogen often display phenotypic variation, and this can negatively impact public health, for example, by reducing the efficacy of preventative measures. Here, we identify that the human pathogen group A Streptococcus (GAS; Streptococcus pyogenes) expresses pili on its cell surface in a serotype-specific manner. Specifically, we show that serotype M3 GAS isolates, which are nonrandomly associated with causing particularly severe and lethal invasive infections, produce negligible amounts of pili relative to serotype M1 and M49 isolates. Performance of an interserotype transcriptome comparison (serotype M1 versus serotype M3) was instrumental in this discovery. We also identified that the transcriptional regulator Nra positively regulates pilus expression in M3 GAS isolates and that the low level of pilus expression of these isolates correlates with a low level of nra transcription. Finally, we discovered that the phenotypic consequences of low levels of pilus expression by M3 GAS isolates are a reduced ability to adhere to host cells and an increased ability to survive and proliferate in human blood. We propose that an enhanced ability to survive in human blood, in part due to reduced pilus expression, is a contributing factor in the association of serotype M3 isolates with highly invasive infections. In conclusion, our data show that GAS isolates express pili in a serotype-dependent manner and may inform vaccine development, given that pilus proteins are being discussed as possible GAS vaccine antigens.
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48
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Gilbert RA, Kelly WJ, Altermann E, Leahy SC, Minchin C, Ouwerkerk D, Klieve AV. Toward Understanding Phage:Host Interactions in the Rumen; Complete Genome Sequences of Lytic Phages Infecting Rumen Bacteria. Front Microbiol 2017; 8:2340. [PMID: 29259581 PMCID: PMC5723332 DOI: 10.3389/fmicb.2017.02340] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 11/13/2017] [Indexed: 11/18/2022] Open
Abstract
The rumen is known to harbor dense populations of bacteriophages (phages) predicted to be capable of infecting a diverse range of rumen bacteria. While bacterial genome sequencing projects are revealing the presence of phages which can integrate their DNA into the genome of their host to form stable, lysogenic associations, little is known of the genetics of phages which utilize lytic replication. These phages infect and replicate within the host, culminating in host lysis, and the release of progeny phage particles. While lytic phages for rumen bacteria have been previously isolated, their genomes have remained largely uncharacterized. Here we report the first complete genome sequences of lytic phage isolates specifically infecting three genera of rumen bacteria: Bacteroides, Ruminococcus, and Streptococcus. All phages were classified within the viral order Caudovirales and include two phage morphotypes, representative of the Siphoviridae and Podoviridae families. The phage genomes displayed modular organization and conserved viral genes were identified which enabled further classification and determination of closest phage relatives. Co-examination of bacterial host genomes led to the identification of several genes responsible for modulating phage:host interactions, including CRISPR/Cas elements and restriction-modification phage defense systems. These findings provide new genetic information and insights into how lytic phages may interact with bacteria of the rumen microbiome.
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Affiliation(s)
- Rosalind A Gilbert
- Department of Agriculture and Fisheries, EcoSciences Precinct, Brisbane, QLD, Australia.,Queensland Alliance for Agriculture and Food Innovation, University of Queensland, St Lucia, QLD, Australia
| | | | - Eric Altermann
- AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand.,Riddet Institute, Massey University, Palmerston North, New Zealand
| | - Sinead C Leahy
- AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand.,New Zealand Agricultural Greenhouse Gas Research Centre, Palmerston North, New Zealand
| | - Catherine Minchin
- Department of Agriculture and Fisheries, EcoSciences Precinct, Brisbane, QLD, Australia
| | - Diane Ouwerkerk
- Department of Agriculture and Fisheries, EcoSciences Precinct, Brisbane, QLD, Australia.,Queensland Alliance for Agriculture and Food Innovation, University of Queensland, St Lucia, QLD, Australia
| | - Athol V Klieve
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, St Lucia, QLD, Australia.,School of Agriculture and Food Sciences, University of Queensland, Gatton Campus, Gatton, QLD, Australia
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49
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Requirement and Synergistic Contribution of Platelet-Activating Factor Acetylhydrolase Sse and Streptolysin S to Inhibition of Neutrophil Recruitment and Systemic Infection by Hypervirulent emm3 Group A Streptococcus in Subcutaneous Infection of Mice. Infect Immun 2017; 85:IAI.00530-17. [PMID: 28947648 DOI: 10.1128/iai.00530-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 09/18/2017] [Indexed: 01/18/2023] Open
Abstract
Hypervirulent group A streptococcus (GAS) can inhibit neutrophil recruitment and cause systemic infection in a mouse model of skin infection. The purpose of this study was to determine whether platelet-activating factor acetylhydrolase Sse and streptolysin S (SLS) have synergistic contributions to inhibition of neutrophil recruitment and systemic infection in subcutaneous infection of mice by MGAS315, a hypervirulent genotype emm3 GAS strain. Deletion of sse and sagA in MGAS315 synergistically reduced the skin lesion size and GAS burden in the liver and spleen. However, the mutants were persistent at skin sites and had similar growth factors in nonimmune blood. Thus, the low numbers of Δsse ΔsagA mutants in the liver and spleen were likely due to their reduction in the systemic dissemination. Few intact and necrotic neutrophils were detected at MGAS315 infection sites. In contrast, many neutrophils and necrotic cells were present at the edge of Δsse mutant infection sites on day 1 and at the edge of and inside Δsse mutant infection sites on day 2. ΔsagA mutant infection sites had massive numbers of and few intact neutrophils at the edge and center of the infection sites, respectively, on day 1 and were full of intact neutrophils or necrotic cells on day 2. Δsse ΔsagA mutant infection sites had massive numbers of intact neutrophils throughout the whole infection site. These sse and sagA deletion-caused changes in the histological pattern at skin infection sites could be complemented. Thus, the sse and sagA deletions synergistically enhance neutrophil recruitment. These findings indicate that both Sse and SLS are required but that neither is sufficient for inhibition of neutrophil recruitment and systemic infection by hypervirulent GAS.
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Herrera AL, Suso K, Allison S, Simon A, Schlenker E, Huber VC, Chaussee MS. Binding host proteins to the M protein contributes to the mortality associated with influenza- Streptococcus pyogenes superinfections. MICROBIOLOGY-SGM 2017; 163:1445-1456. [PMID: 28942759 DOI: 10.1099/mic.0.000532] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The mortality associated with influenza A virus (IAV) is often due to the development of secondary bacterial infections known as superinfections. The group A streptococcus (GAS) is a relatively uncommon cause of IAV superinfections, but the mortality of these infections is high. We used a murine model to determine whether the surface-localized GAS M protein contributes to the outcome of IAV-GAS superinfections. A comparison between wild-type GAS and an M protein mutant strain (emm3) showed that the M3 protein was essential to virulence. To determine whether the binding, or recruitment, of host proteins to the bacterial surface contributed to virulence, GAS was suspended with BALF collected from mice that had recovered from a sub-lethal infection with IAV. Following intranasal inoculation of naïve mice, the mortality associated with the wild-type strain, but not the emm3 mutant strain, was greater compared to mice inoculated with GAS suspended with either BALF from uninfected mice or PBS. Further analyses showed that both albumin and fibrinogen (Fg) were more abundant in the respiratory tract 8 days after IAV infection, that M3 bound both proteins to the bacterial surface, and that suspension of GAS with either protein increased GAS virulence in the absence of antecedent IAV infection. Overall, the results showed that M3 is essential to the virulence of GAS in an IAV superinfection and suggested that increased abundance of albumin and Fg in the respiratory tract following IAV infection enhanced host susceptibility to secondary GAS infection.
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Affiliation(s)
- Andrea L Herrera
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Kuta Suso
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Stephanie Allison
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Abby Simon
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Evelyn Schlenker
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Victor C Huber
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Michael S Chaussee
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
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