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Praseetha S, Sukumaran ST, Dan M, Augustus AR, Pandian SK, Sugathan S. The Anti-Biofilm Potential of Linalool, a Major Compound from Hedychium larsenii, against Streptococcus pyogenes and Its Toxicity Assessment in Danio rerio. Antibiotics (Basel) 2023; 12:545. [PMID: 36978412 PMCID: PMC10044342 DOI: 10.3390/antibiotics12030545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/05/2023] [Accepted: 03/07/2023] [Indexed: 03/11/2023] Open
Abstract
The anti-biofilm and anti-virulence potential of the essential oil (E.O.) extracted from Hedychium larsenii M. Dan & Sathish was determined against Streptococcus pyogenes. A crystal violet assay was employed to quantify the biofilm. Linalool, a monoterpene alcohol from the E.O., showed concentration-dependent biofilm inhibition, with a maximum of 91% at a concentration of 0.004% (v/v). The AlamarBlueTM assay also confirmed Linalool's non-bactericidal anti-biofilm efficacy (0.004%). Linalool treatment impeded micro-colony formation, mature biofilm architecture, surface coverage, and biofilm thickness and impaired cell surface hydrophobicity and EPS production. Cysteine protease synthesis was quantified using the Azocasein assay, and Linalool treatment augmented its production. This suggests that Linalool destabilizes the biofilm matrix. It altered the expression of core regulons covRS, mga, srv, and ropB, and genes associated with virulence and biofilm formation, such as speB, dltA, slo, hasA, and ciaH, as revealed by qPCR analysis. Cytotoxicity analysis using human kidney cells (HEK) and the histopathological analysis in Danio rerio proved Linalool to be a druggable molecule against the biofilms formed by S. pyogenes. This is the first report on Linalool's anti-biofilm and anti-virulence potential against S. pyogenes.
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Affiliation(s)
- Sarath Praseetha
- Department of Biotechnology, Kariavattom Campus, University of Kerala, Thiruvananthapuram Pin-695 581, Kerala, India
| | - Swapna Thacheril Sukumaran
- Department of Botany, Kariavattom Campus, University of Kerala, Thiruvananthapuram Pin-695 581, Kerala, India
| | - Mathew Dan
- Plant Genetic Resource Division, Jawaharlal Nehru Tropical Botanic Garden & Research Institute, Palode, Thiruvananthapuram Pin-695 562, Kerala, India
| | - Akshaya Rani Augustus
- Department of Biotechnology, Alagappa University, Karaikudi Pin-630 003, Tamil Nadu, India
| | | | - Shiburaj Sugathan
- Department of Botany, Kariavattom Campus, University of Kerala, Thiruvananthapuram Pin-695 581, Kerala, India
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Jiang X, Lin A, Li S, Shi Y, Zhou F, Felix Gomez GG, Gregory RL, Zhang C, Chen S, Huang R. Effects of artificial honey and epigallocatechin-3-gallate on streptococcus pyogenes. BMC Microbiol 2022; 22:207. [PMID: 36028794 PMCID: PMC9419396 DOI: 10.1186/s12866-022-02611-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 08/04/2022] [Indexed: 12/01/2022] Open
Abstract
Background Streptococcus pyogenes is an important global human pathogen that causes pharyngitis, and antibacterial therapy has become an important part of the overall therapy for pharyngitis. As natural derivatives, honey and green tea are often recommended for patients with pharyngitis in traditional Chinese medicine without experimental theoretical basis on wether the combined effect of honey and green tea on pharyngitis is better than they alone. The aims of this study were to explore the effects of artificial honey (AH) and epigallocatechin-3-gallate (EGCG) on S. pyogenes and elucidate the possible mechanisms, which were investigated using MIC (the minimum inhibitory concentration), FIC (fractional inhibitory concentration) index, growth pattern, biofilm formation and RT-qPCR. Results The MIC of AH on S. pyogenes was 12.5% (v/v) and the MIC of EGCG was 1250 μg/ml. The FIC index of AH and EGCG was 0.5. The planktonic cell growth, growth pattern and biofilm formation assays showed that AH and EGCG mixture had stronger inhibitory effect on S. pyogenes than they alone. RT-qPCR confirmed that the expression of hasA and luxS gene were inhibited by AH and EGCG mixture. Conclusions AH and EGCG mixture can inhibit the planktonic cell growth, biofilm formation and some virulence genes expression of S. pyogenes, better than they alone. The combination of honey and green tea have the potential to treat pharyngitis as natural derivatives, avoiding drug resistance and double infection.
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Affiliation(s)
- Xiaoge Jiang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.,Department of Orthodontics Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - An Lin
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.,Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Shijia Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.,Department of Orthodontics Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Yangyang Shi
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.,Department of Endodontic Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Fangjie Zhou
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.,Department of Endodontic Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | | | - Richard L Gregory
- Department of Oral Biology, School of Dentistry, Indiana University, Indianapolis, USA
| | - Chaoliang Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Song Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China. .,Department of Orthodontics Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
| | - Ruijie Huang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China. .,Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China. .,Department of Oral Biology, School of Dentistry, Indiana University, Indianapolis, USA.
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Banerji R, Iyer P, Saroj SD. Spermidine enhances the survival of Streptococcus pyogenes M3 under oxidative stress. Mol Oral Microbiol 2022; 37:53-62. [PMID: 34994090 DOI: 10.1111/omi.12360] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 12/23/2021] [Accepted: 12/30/2021] [Indexed: 12/17/2022]
Abstract
Streptococcus pyogenes, a host-restricted gram-positive pathogen during infection, initially adheres to the epithelia of the nasopharynx and respiratory tract of the human host, followed by disseminating to other organs and evading the host immune system. Upon phagocytosis, S. pyogenes encounters oxidative stress inside the macrophages. The role of polyamines in regulating various physiological functions including stress resistance in bacteria has been reported widely. Since S. pyogenes lacks the machinery for the biosynthesis of polyamines, the study aimed to understand the role of extracellular polyamines in the survival of S. pyogenes under oxidative stress environments. S. pyogenes being a catalase-negative organism, we report that its survival within the macrophages and H2 O2 is enhanced by the presence of spermidine. The increased survival can be attributed to the upregulation of oxidative stress response genes such as sodM, npx, and mtsABC. In addition, spermidine influences the upregulation of virulence factors such as sagA, slo, and hasA. Also, spermidine leads to a decrease in hydrophobicity of the cell membrane and an increase in hyaluronic acid. This study suggests a role for extracellular spermidine in the survival of S. pyogenes under oxidative stress environments. Recognizing the factors that modulate S. pyogenes survival and virulence under stress will assist in understanding its interactions with the host.
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Affiliation(s)
- Rajashri Banerji
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, Maharashtra, India
| | - Parvati Iyer
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, Maharashtra, India
| | - Sunil D Saroj
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, Maharashtra, India
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Tsaplina O, Khmel I, Zaitseva Y, Khaitlina S. The Role of SprIR Quorum Sensing System in the Regulation of Serratia proteamaculans 94 Invasion. Microorganisms 2021; 9:microorganisms9102082. [PMID: 34683403 PMCID: PMC8537836 DOI: 10.3390/microorganisms9102082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/27/2021] [Accepted: 09/29/2021] [Indexed: 01/20/2023] Open
Abstract
The bacteria Serratia proteamaculans 94 have a LuxI/LuxR type QS system consisting of AHL synthase SprI and the regulatory receptor SprR. We have previously shown that inactivation of the AHL synthase sprI gene resulted in an increase in the invasive activity of S. proteamaculans correlated with an increased bacterial adhesion. In the present work, the effects of inactivation of the S. proteamaculans receptor SprR are studied. Our results show that inactivation of the receptor sprR gene leads to an increase in bacterial invasion without any increase in their adhesion. On the other hand, inactivation of the sprR gene increases the activity of the extracellular protease serralysin. Inactivation of the QS system does not affect the activity of the pore-forming toxin ShlA and prevents the ShlA activation under conditions of a limited concentration of iron ions typical of the human body. While the wild type strain shows increased invasion in the iron-depleted medium, deletion of its QS system leads to a decrease in host cell invasion, which is nevertheless similar to the level of the wild type S. proteamaculans grown in the iron-rich medium. Thus, inactivation of either of the two component of the S. proteamaculans LuxI/LuxR-type QS system leads to an increase in the invasive activity of these bacteria through different mechanisms and prevents invasion under the iron-limited conditions.
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Affiliation(s)
- Olga Tsaplina
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky av. 4, 194064 St Petersburg, Russia;
- Correspondence: ; Tel.: +7-812-297-42-96
| | - Inessa Khmel
- Institute of Molecular Genetics of National Research Center “Kurchatov Institute”, Kurchatov sq. 2, 123182 Moscow, Russia; (I.K.); (Y.Z.)
| | - Yulia Zaitseva
- Institute of Molecular Genetics of National Research Center “Kurchatov Institute”, Kurchatov sq. 2, 123182 Moscow, Russia; (I.K.); (Y.Z.)
- Laboratory of Biotechnology and Applied Bioelementology, Demidov Yaroslavl State University, Sovetskaya Str. 14, 150003 Yaroslavl, Russia
| | - Sofia Khaitlina
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky av. 4, 194064 St Petersburg, Russia;
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Revisiting the inoculum effect for Streptococcus pyogenes with a hollow fibre infection model. Eur J Clin Microbiol Infect Dis 2021; 40:2137-2144. [PMID: 33948751 DOI: 10.1007/s10096-021-04262-x] [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: 01/20/2021] [Accepted: 04/20/2021] [Indexed: 10/21/2022]
Abstract
Severe, invasive Streptococcus pyogenes (Strep A) infections result in greater than 500,000 deaths annually. First line treatment for such infections is benzylpenicillin, often with the addition of clindamycin, but treatment failure can occur with this regimen. This failure has been partially attributed to the inoculum effect, which presents as reduced antibiotic susceptibility during high bacterial density and plateau-phase growth. Hollow fibre infection models (HFIM) have been proposed as an in vitro alternative to in vivo research to study these effects. To re-evaluate the inoculum effect for benzylpenicillin, clindamycin, linezolid, and trimethoprim-sulfamethoxazole using a Strep A HFIM. Differential antibiotic susceptibility of Strep A was measured in a HFIM starting from low- and high-density inocula with an average difference in bacterial concentration of 56-fold. Dynamic antibiotic concentrations were delivered over 48 h to simulate in vivo human pharmacokinetics in an in vitro model. Differences in antibiotic susceptibility were measured by plate count of colony-forming units over time. Inoculum effects were seen in benzylpenicillin and linezolid at 24 h, and benzylpenicillin, linezolid, and clindamycin at 48 h. The effect size was greatest for continuously infused benzylpenicillin at 48 h with a log10-fold difference of 4.02 between groups. No inoculum effect was seen in trimethoprim-sulfamethoxazole, with a maximal log10-fold difference of 0.40. Inoculum effects were seen using benzylpenicillin, linezolid, and clindamycin, which may predict reduced clinical efficacy following treatment delay. The model has proven robust and largely in agreeance with published data, recommending it for further Strep A study.
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Deciphering Streptococcal Biofilms. Microorganisms 2020; 8:microorganisms8111835. [PMID: 33233415 PMCID: PMC7700319 DOI: 10.3390/microorganisms8111835] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/10/2020] [Accepted: 11/17/2020] [Indexed: 12/19/2022] Open
Abstract
Streptococci are a diverse group of bacteria, which are mostly commensals but also cause a considerable proportion of life-threatening infections. They colonize many different host niches such as the oral cavity, the respiratory, gastrointestinal, and urogenital tract. While these host compartments impose different environmental conditions, many streptococci form biofilms on mucosal membranes facilitating their prolonged survival. In response to environmental conditions or stimuli, bacteria experience profound physiologic and metabolic changes during biofilm formation. While investigating bacterial cells under planktonic and biofilm conditions, various genes have been identified that are important for the initial step of biofilm formation. Expression patterns of these genes during the transition from planktonic to biofilm growth suggest a highly regulated and complex process. Biofilms as a bacterial survival strategy allow evasion of host immunity and protection against antibiotic therapy. However, the exact mechanisms by which biofilm-associated bacteria cause disease are poorly understood. Therefore, advanced molecular techniques are employed to identify gene(s) or protein(s) as targets for the development of antibiofilm therapeutic approaches. We review our current understanding of biofilm formation in different streptococci and how biofilm production may alter virulence-associated characteristics of these species. In addition, we have summarized the role of surface proteins especially pili proteins in biofilm formation. This review will provide an overview of strategies which may be exploited for developing novel approaches against biofilm-related streptococcal infections.
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Vijayakumar K, Manigandan V, Jeyapragash D, Bharathidasan V, Anandharaj B, Sathya M. Eucalyptol inhibits biofilm formation of Streptococcus pyogenes and its mediated virulence factors. J Med Microbiol 2020; 69:1308-1318. [PMID: 32930658 DOI: 10.1099/jmm.0.001253] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Introduction. Streptococcus pyogenes is a diverse virulent synthesis pathogen responsible for invasive systemic infections. Establishment of antibiotic resistance in the pathogen has produced a need for new antibiofilm agents to control the biofilm formation and reduce biofilm-associated resistance development.Aim. The present study investigates the in vitro antibiofilm activity of eucalyptol against S. pyogenes.Methodology. The antibiofilm potential of eucalyptol was assessed using a microdilution method and their biofilm inhibition efficacy was visualized by microscopic analysis. The biochemical assays were performed to assess the influence of eucalyptol on virulence productions. Real-time PCR analysis was performed to evaluate the expression profile of the virulence genes.Results. Eucalyptol showed significant antibiofilm potential in a dose-dependent manner without affecting bacterial growth. Eucalyptol at 300 µg ml-1 (biofilm inhibitory concentration) significantly inhibited the initial stage of biofilm formation in S. pyogenes. However, eucalyptol failed to diminish the mature biofilms of S. pyogenes at biofilm inhibitory concentration and it effectively reduced the biofilm formation on stainless steel, titanium, and silicone surfaces. The biochemical assay results revealed that eucalyptol greatly affects the cell-surface hydrophobicity, auto-aggregation, extracellular protease, haemolysis and hyaluronic acid synthesis. Further, the gene-expression analysis results showed significant downregulation of virulence gene expression upon eucalyptol treatment.Conclusion. The present study suggests that eucalyptol applies its antibiofilm assets by intruding the initial biofilm formation of S. pyogenes. Supplementary studies are needed to understand the mode of action involved in biofilm inhibition.
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Affiliation(s)
- Karuppiah Vijayakumar
- Centre of advanced study in Marine Biology, Annamalai University, Parangipettai - 608 502, Tamil Nadu, India
| | - Vajravelu Manigandan
- Centre of advanced study in Marine Biology, Annamalai University, Parangipettai - 608 502, Tamil Nadu, India
| | - Danaraj Jeyapragash
- Department of Biotechnology, Karpagam academy of higher education, Eachanari, Coimbatore-641 021, Tamil Nadu, India
| | - Veeraiyan Bharathidasan
- Centre of advanced study in Marine Biology, Annamalai University, Parangipettai - 608 502, Tamil Nadu, India
| | - Balaiyan Anandharaj
- Department of Botany, Annamalai University, Annamalai Nagar, Chidambaram - 608 002, Tamil Nadu, India
| | - Madhavan Sathya
- Department of Botany, Annamalai University, Annamalai Nagar, Chidambaram - 608 002, Tamil Nadu, India
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Vyas HKN, Proctor EJ, McArthur J, Gorman J, Sanderson-Smith M. Current Understanding of Group A Streptococcal Biofilms. Curr Drug Targets 2020; 20:982-993. [PMID: 30947646 PMCID: PMC6700754 DOI: 10.2174/1389450120666190405095712] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 04/01/2019] [Accepted: 04/02/2019] [Indexed: 02/01/2023]
Abstract
Background: It has been proposed that GAS may form biofilms. Biofilms are microbial communities that aggregate on a surface, and exist within a self-produced matrix of extracellular polymeric substances. Biofilms offer bacteria an increased survival advantage, in which bacteria persist, and resist host immunity and antimicrobial treatment. The biofilm phenotype has long been recognized as a virulence mechanism for many Gram-positive and Gram-negative bacteria, however very little is known about the role of biofilms in GAS pathogenesis. Objective: This review provides an overview of the current knowledge of biofilms in GAS pathogenesis. This review assesses the evidence of GAS biofilm formation, the role of GAS virulence factors in GAS biofilm formation, modelling GAS biofilms, and discusses the polymicrobial nature of biofilms in the oropharynx in relation to GAS. Conclusion: Further study is needed to improve the current understanding of GAS as both a mono-species biofilm, and as a member of a polymicrobial biofilm. Improved modelling of GAS biofilm formation in settings closely mimicking in vivo conditions will ensure that biofilms generated in the lab closely reflect those occurring during clinical infection.
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Affiliation(s)
- Heema K N Vyas
- School of Chemistry and Molecular Bioscience, and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Emma-Jayne Proctor
- School of Chemistry and Molecular Bioscience, and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Jason McArthur
- School of Chemistry and Molecular Bioscience, and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Jody Gorman
- School of Chemistry and Molecular Bioscience, and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Martina Sanderson-Smith
- School of Chemistry and Molecular Bioscience, and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
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Adil M, Baig MH, Rupasinghe HV. Impact of Citral and Phloretin, Alone and in Combination, on Major Virulence Traits of Streptococcus pyogenes. Molecules 2019; 24:molecules24234237. [PMID: 31766432 PMCID: PMC6930587 DOI: 10.3390/molecules24234237] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/18/2019] [Accepted: 11/19/2019] [Indexed: 11/17/2022] Open
Abstract
Streptococcus pyogenes is well documented as a multi-virulent and exclusively human pathogen. The LuxS-based signaling in these bacteria has a crucial role in causing several infections through pathways that are pathogenic. This study evaluated the individual and synergistic effects of citral and phloretin against S. pyogenes in relation to major virulence traits. The in vitro synergy of citral and phloretin was evaluated by the checkerboard method. The fractional inhibitory concentration (FIC) values were calculated to determine the interactions between the inhibitors. The bacteria’s virulence properties were tested in the presence of the molecules, individually as well as in combination. Molecules’ cytotoxicity was tested using human tonsil epithelial cells. The synergistic effects of the molecules on the expression of biofilm and quorum sensing genes were tested using quantitative real-time polymerase chain reaction (qRT-PCR). The molecules were also tested for their impact on LuxS protein by molecular docking, modeling, and free-energy calculations. When the two molecules were assessed in combination (synergistic effect, FIC Index of 0.5), a stronger growth inhibitory activity was exhibited than the individual molecules. The cell surface hydrophobicity, as well as genes involved in quorum sensing and biofilm formation, showed greater suppression when the molecules were tested in combination. The in silico findings also suggest the inhibitory potential of the two molecules against LuxS protein. The binding orientation and the binding affinity of citral and phloretin well support the notion that there is a synergistic effect of citral and phloretin. The data reveal the combination of citral and phloretin as a potent antibacterial agent to combat the virulence of S. pyogenes.
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Affiliation(s)
- Mohd Adil
- Department of Plant, Food, and Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada;
| | - Mohd Hassan Baig
- Department of Family Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, 211 Eonju-ro, Gangnam-gu, Seoul 06273, Korea;
| | - H.P. Vasantha Rupasinghe
- Department of Plant, Food, and Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada;
- Department of Pathology, Faculty of Medicine, Dalhousie University, Halifax, NS B3H 4H7, Canada
- Correspondence:
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Nandu TG, Subramenium GA, Shiburaj S, Viszwapriya D, Iyer PM, Balamurugan K, Rameshkumar KB, Karutha Pandian S. Fukugiside, a biflavonoid from Garcinia travancorica inhibits biofilm formation of Streptococcus pyogenes and its associated virulence factors. J Med Microbiol 2018; 67:1391-1401. [PMID: 30052177 DOI: 10.1099/jmm.0.000799] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
PURPOSE Streptococcus pyogenes, a notorious human pathogen thatis responsible for various invasive and non-invasive diseases, possesses multiple virulence armaments, including biofilm formation. The current study demonstrates the anti-biofilm and anti-virulence potential of fukugiside, a biflavonoid isolated from Garciniatravancorica, against S. pyogenes. METHODOLOGY The anti-biofilm activity of fukugiside was assessed and established using microdilution and microscopic analysis. Biochemical assays were performed to assess the effects of fukugiside on important virulence factors, which were further validated using quantitative real-time PCR and in vivo analysis in Caenorhabditis elegans. RESULTS Fukugiside exhibited concentration-dependent biofilm inhibition (79 to 96 %) against multiple M serotypes of S. pyogenes (M1, M56, M65, M74, M100 and st38) with a minimum biofilm inhibitory concentration of 80 µg ml-1. Electron microscopy and biochemical assay revealed a significant reduction in extracellular polymeric substance production. The results for the microbial adhesion to hydrocarbon assay, extracellular protease quantification and differential regulation of the dltA, speB, srv and ropB genes suggested that fukugiside probably inhibits biofilm formation by lowering cell surface hydrophobicity and destabilizing the biofilm matrix. The enhanced susceptibility to phagocytosis evidenced in the blood survival assay goes in unison with the downregulation of mga. The downregulation of important virulence factor-encoding genes such as hasA, slo and col370 suggested impaired virulence. In vivo analysis in C. elegans evinced the non-toxic nature of fukugiside and its anti-virulence potential against S. pyogenes. CONCLUSION Fukugiside exhibits potent anti-biofilm and anti-virulence activity against different M serotypes of S. pyogenes. It is also non-toxic, which augurs well for its clinical application.
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Affiliation(s)
- Thrithamarassery Gangadharan Nandu
- 1Division of Microbiology, Jawaharlal Nehru Tropical Botanic Garden and Research Institute, Palode, Thiruvananthapuram-695562, Kerala, India
| | | | - Sugathan Shiburaj
- 1Division of Microbiology, Jawaharlal Nehru Tropical Botanic Garden and Research Institute, Palode, Thiruvananthapuram-695562, Kerala, India
| | - Dharmaprakash Viszwapriya
- 2Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 004, Tamil Nadu, India
| | - Prasanth Mani Iyer
- 2Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 004, Tamil Nadu, India
| | - Krishnaswamy Balamurugan
- 2Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 004, Tamil Nadu, India
| | - Koranappallil Bahuleyan Rameshkumar
- 3Division of Phytochemistry and Phytopharmacology, Jawaharlal Nehru Tropical Botanic Garden and Research Institute, Palode, Thiruvananthapuram-695562, Kerala, India
| | - Shunmugiah Karutha Pandian
- 2Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 004, Tamil Nadu, India
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11
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Sitkiewicz I, Musser JM. Deletion of from Streptococcus pyogenes. Results in Hypervirulence in a Mouse Model of Sepsis and is LuxS Independent. Pol J Microbiol 2018; 66:17-24. [PMID: 29359701 DOI: 10.5604/17331331.1234989] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Group A Streptococcus (GAS) is a Gram-positive human pathogen that causes a variety of diseases ranging from pharyngitis to life-threatening streptococcal toxic shock syndrome. Recently, several global gene expression analyses have yielded extensive new information regarding the regulation of genes encoding known and putative virulence factors in GAS. A microarray analysis found that transcription of the GAS gene M5005_Spy_1343 was significantly increased in response to interaction with human polymorphonuclear leukocytes. M5005_Spy_1343 is predicted to encode a member of the LysR family of transcriptional regulators and is located upstream of a putative operon containing six genes. Five of these genes have sequence similarity to genes involved in short-chain fatty acid metabolism, whereas the sixth gene (luxS) is found in many bacterial species and is involved in quorum sensing. Unexpectedly, inactivation of the M5005_Spy_1343 gene resulted in hypervirulence in an intraperitoneal mouse model of infection. Increased virulence was not due to changes in luxS gene expression. We postulate that short-chain fatty acid metabolism is involved in GAS pathogenesis.
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Affiliation(s)
- Izabela Sitkiewicz
- Department of Molecular Microbiology, National Medicines Institute, Warsaw, Poland
| | - James M Musser
- Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, and Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas, USA
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Ma Y, Hao L, Ke H, Liang Z, Ma J, Liu Z, Li Y. LuxS/AI-2 in Streptococcus agalactiae reveals a key role in acid tolerance and virulence. Res Vet Sci 2017; 115:501-507. [PMID: 28858764 DOI: 10.1016/j.rvsc.2017.07.032] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 07/18/2017] [Accepted: 07/26/2017] [Indexed: 12/30/2022]
Abstract
LuxS-mediated autoinducer-2 (AI-2) directly or indirectly regulates important physiologic function in a variety of bacteria. We found a luxS homologue in the genome of Streptococcus agalactiae, an important pathogen of tilapia. To investigate the relationship between luxS/AI-2 and pathogenicity for tilapia, its bioluminescent activity, acid resistance, cell adherence, virulence, and regulation of virulence gene were evaluated. Compared with the wild-type strain, the bioluminescent activity lost in the luxS mutant, its resistance to acid (pH2.8) was significantly decreased 33.8 times, and furthermore, its adherence to the NGF-2 cell line was dramatically reduced 3 times in the mutant strain. The virulence of the mutant strain was decreased in the tilapia infection model, exogenous AI-2 molecule (7.4nM) and luxS gene complementation with plasmid could complement the deficiencies of function in the luxS mutant strain. These results showed that inactivation of luxS gene caused a significant decrease of bioluminance, acid resistance, cell adhesion, virulence to tilapia and transcription levels of many virulence genes in S. agalactiae. Expression of the known stress resistance factors DnaK and GroEL, relative regulator factors CovR/CovS and virulence factor cpsE verified above results. These findings suggest that luxS may be involved in the interruption of bacterial virulence and resistance to environmental factors.
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Affiliation(s)
- Yanping Ma
- Guangdong Provincial key Laboratory of Livestock Disease Prevention, Guangdong Open Laboratory of Veterinary Public Health, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, PR China
| | - Le Hao
- Guangdong Provincial key Laboratory of Livestock Disease Prevention, Guangdong Open Laboratory of Veterinary Public Health, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, PR China
| | - Hao Ke
- Guangdong Provincial key Laboratory of Livestock Disease Prevention, Guangdong Open Laboratory of Veterinary Public Health, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, PR China
| | - Zhiling Liang
- Guangdong Provincial key Laboratory of Livestock Disease Prevention, Guangdong Open Laboratory of Veterinary Public Health, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, PR China
| | - Jiangyao Ma
- Guangdong Provincial key Laboratory of Livestock Disease Prevention, Guangdong Open Laboratory of Veterinary Public Health, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, PR China
| | - Zhenxing Liu
- Guangdong Provincial key Laboratory of Livestock Disease Prevention, Guangdong Open Laboratory of Veterinary Public Health, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, PR China.
| | - Yugu Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China.
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Inhibitory role of acyl homoserine lactones in hemolytic activity and viability of Streptococcus pyogenes M6 S165. Sci Rep 2017; 7:44902. [PMID: 28303956 PMCID: PMC5355980 DOI: 10.1038/srep44902] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 02/14/2017] [Indexed: 12/28/2022] Open
Abstract
Streptococcus pyogenes an adapted human pathogen asymptomatically colonizes the nasopharynx, among other polymicrobial communities. However, information on the events leading to the colonization and expression of virulence markers subject to interspecies and host-bacteria interactions are limited. The interference of acyl homoserine lactones (AHLs) with the hemolytic activity and viability of S. pyogenes M6 S165 was examined. AHLs, with fatty acid side chains ≥12 carbon atoms, inhibited hemolytic activity by downregulating the expression of the sag operon involved in the production of streptolysin S. Inhibitory AHLs upregulated the expression of transcriptional regulator LuxR. Electrophoretic mobility shift assays revealed the interaction of LuxR with the region upstream of sagA. AHL-mediated bactericidal activity observed at higher concentrations (mM range) was an energy-dependent process, constrained by the requirement of glucose and iron. Ferrichrome transporter FtsABCD facilitated transport of AHLs across the streptococcal membrane. The study demonstrates a previously unreported role for AHLs in S. pyogenes virulence.
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14
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Afzal M, Manzoor I, Kuipers OP, Shafeeq S. Cysteine-Mediated Gene Expression and Characterization of the CmbR Regulon in Streptococcus pneumoniae. Front Microbiol 2016; 7:1929. [PMID: 27990139 PMCID: PMC5131005 DOI: 10.3389/fmicb.2016.01929] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 11/16/2016] [Indexed: 11/13/2022] Open
Abstract
In this study, we investigated the transcriptomic response of Streptococcus pneumoniae D39 to cysteine. Transcriptome comparison of the D39 wild-type grown at a restricted concentration of cysteine (0.03 mM) to one grown at a high concentration of cysteine (50 mM) in chemically-defined medium (CDM) revealed elevated expression of various genes/operons, i.e., spd-0150, metQ, spd-0431, metEF, gshT, spd-0618, fhs, tcyB, metB-csd, metA, spd-1898, yvdE, and cysK, likely to be involved in the transport and utilization of cysteine and/or methionine. Microarray-based data were further confirmed by quantitative RT-PCR. Promoter lacZ-fusion studies and quantitative RT-PCR data showed that the transcriptional regulator CmbR acts as a transcriptional repressor of spd-0150, metEF, gshT, spd-0618, tcyB, metA, and yvdE, putatively involved in cysteine uptake and utilization. The operator site of CmbR in the promoter regions of CmbR-regulated genes is predicted and confirmed by mutating or deleting CmbR operator sites from the promoter regions of these genes.
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Affiliation(s)
- Muhammad Afzal
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands; Department of Bioinformatics and Biotechnology, Government College UniversityFaisalabad, Pakistan
| | - Irfan Manzoor
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands; Department of Bioinformatics and Biotechnology, Government College UniversityFaisalabad, Pakistan
| | - Oscar P Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Groningen, Netherlands
| | - Sulman Shafeeq
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet Stockholm, Sweden
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15
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Abstract
Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance.
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Skolnik K, Nguyen A, Somayaji R, Thornton CS, Waddell B, Surette MG, Rabin HR, Parkins MD. Clinical implications and characterization of Group A Streptoccoccus infections in adults with cystic fibrosis. BMC Pulm Med 2015; 15:161. [PMID: 26651825 PMCID: PMC4676819 DOI: 10.1186/s12890-015-0157-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 12/08/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Persistent airway infection is a hallmark feature of cystic fibrosis (CF). However, increasingly it has been observed that non-classical pathogens may transiently infect CF lower airways. Streptococcus pyogenes (Group A Streptococcus; (GAS)) is an uncommon but potentially dangerous cause of community-acquired pneumonia. Our aim was to determine the incidence, natural history, and clinical impact of GAS infections in CF and phenotypically and genotypically characterize the isolates. METHODS We retrospectively evaluated the Calgary Adult CF Clinic biobank to identify adults with at least one GAS isolate. Patient demographics, medical and pulmonary exacerbation (PEx) histories were evaluated. The primary outcome was PEx occurrence at incident GAS culture. Secondary outcomes evaluated were changes in lung function and PEx frequency following GAS isolation. Isolates were assessed for extra-cellular virulence factor production capacity and ability to produce quorum sensing (AI-2). Isolates were genotyped using pulse-field gel electrophoresis (PFGE). RESULTS Fifteen individuals who cultured GAS twenty times were identified. At the time of GAS isolation, 47% (7/15) of subjects experienced a PEx and half of these (4/7) were severe. Individuals were more likely to have a PEx at the time of the index GAS isolate compared to the preceding visit (RR = 6.0, 95% CI 0.82-43.0, p = 0.08), particularly if GAS was the numerically dominant sputum pathogen (RR = 6.5, 95% CI 1.00-43.0, p = 0.009). There were no changes in PEx frequency or rate of lung function decline following GAS. None of the patients developed chronic airways infection, bacteremia, necrotizing pneumonia or empyema. Susceptibility was universal to common anti-Streptococcal antibiotics and anti-Pseudomonal antibiotics commonly used in CF, with the exception of azithromycin. GAS isolates varied in their production of protease, DNase, and AI-2 but these did not correlate with PEx, and none produced elastase, chrondrotin sulfatase or H202. One patient had prolonged carriage with the same isolate and two patients had isolates with similar PFGE patterns. CONCLUSIONS GAS was an uncommon lower respiratory pathogen of adults with CF. Identification of GAS in sputum was frequently associated with PEx, particularly when numerically dominant. However, transient GAS infection did not result in chronic infection nor appreciably change long-term disease trajectory.
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Affiliation(s)
- Kate Skolnik
- Departments of Medicine, The University of Calgary, Calgary, AB, Canada.
| | - Austin Nguyen
- Departments of Microbiology, Immunology and Infectious Diseases, The University of Calgary, 3330 Hospital Drive, NW, Calgary, AB, Canada.
| | - Ranjani Somayaji
- Departments of Medicine, The University of Calgary, Calgary, AB, Canada. .,Departments of Microbiology, Immunology and Infectious Diseases, The University of Calgary, 3330 Hospital Drive, NW, Calgary, AB, Canada.
| | - Christina S Thornton
- Departments of Microbiology, Immunology and Infectious Diseases, The University of Calgary, 3330 Hospital Drive, NW, Calgary, AB, Canada.
| | - Barbara Waddell
- Departments of Microbiology, Immunology and Infectious Diseases, The University of Calgary, 3330 Hospital Drive, NW, Calgary, AB, Canada.
| | - Michael G Surette
- Department of Medicine, McMaster University, Hamilton, ON, Canada. .,Department of Biochemistry, McMaster University, Hamilton, ON, Canada. .,The Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada.
| | - Harvey R Rabin
- Departments of Medicine, The University of Calgary, Calgary, AB, Canada. .,Departments of Microbiology, Immunology and Infectious Diseases, The University of Calgary, 3330 Hospital Drive, NW, Calgary, AB, Canada.
| | - Michael D Parkins
- Departments of Medicine, The University of Calgary, Calgary, AB, Canada. .,Departments of Microbiology, Immunology and Infectious Diseases, The University of Calgary, 3330 Hospital Drive, NW, Calgary, AB, Canada.
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Ashwinkumar Subramenium G, Viszwapriya D, Iyer PM, Balamurugan K, Karutha Pandian S. covR Mediated Antibiofilm Activity of 3-Furancarboxaldehyde Increases the Virulence of Group A Streptococcus. PLoS One 2015; 10:e0127210. [PMID: 25978065 PMCID: PMC4433207 DOI: 10.1371/journal.pone.0127210] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 04/13/2015] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Group A streptococcus (GAS, Streptococcus pyogenes), a multi-virulent, exclusive human pathogen responsible for various invasive and non-invasive diseases possesses biofilm forming phenomenon as one of its pathogenic armaments. Recently, antibiofilm agents have gained prime importance, since inhibiting the biofilm formation is expected to reduce development of antibiotic resistance and increase their susceptibility to the host immune cells. PRINCIPAL FINDINGS The current study demonstrates the antibiofilm activity of 3Furancarboxaldehyde (3FCA), a floral honey derived compound, against GAS biofilm, which was divulged using crystal violet assay, light microscopy, and confocal laser scanning microscopy. The report is extended to study its effect on various aspects of GAS (morphology, virulence, aggregation) at its minimal biofilm inhibitory concentration (132μg/ml). 3FCA was found to alter the growth pattern of GAS in solid and liquid medium and increased the rate of auto-aggregation. Electron microscopy unveiled the increase in extra polymeric substances around cell. Gene expression studies showed down-regulation of covR gene, which is speculated to be the prime target for the antibiofilm activity. Increased hyaluronic acid production and down regulation of srtB gene is attributed to the enhanced rate of auto-aggregation. The virulence genes (srv, mga, luxS and hasA) were also found to be over expressed, which was manifested with the increased susceptibility of the model organism Caenorhabditis elegans to 3FCA treated GAS. The toxicity of 3FCA was ruled out with no adverse effect on C. elegans. SIGNIFICANCE Though 3FCA possess antibiofilm activity against GAS, it was also found to increase the virulence of GAS. This study demonstrates that, covR mediated antibiofilm activity may increase the virulence of GAS. This also emphasizes the importance to analyse the acclimatization response and virulence of the pathogen in the presence of antibiofilm compounds prior to their clinical trials.
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Affiliation(s)
| | | | - Prasanth Mani Iyer
- Department of Biotechnology, Alagappa University, Science Campus, Karaikudi, Tamil Nadu, India
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18
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The interaction between Streptococcus spp. and Veillonella tobetsuensis in the early stages of oral biofilm formation. J Bacteriol 2015; 197:2104-2111. [PMID: 25917902 DOI: 10.1128/jb.02512-14] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dental plaque is a multispecies oral biofilm, the development of which is initiated by adherence of the pioneer Streptococcus spp. Oral Veillonella spp., including V. atypica, V. denticariosi, V. dispar, V. parvula, V. rogosae, and V. tobetsuensis, are known as early colonizers in oral biofilm formation. These species have been reported to co-aggregate with Streptococcus spp. in a metabolic cooperation-dependent manner to form biofilms in human oral cavities, especially in the early stages of biofilm formation. However, in our previous study, Streptococcus gordonii showed biofilm formation to the greatest extent in the presence of V. tobetsuensis, without co-aggregation between species. These results suggest that V. tobetsuensis produces signaling molecules that promote the proliferation of S. gordonii in biofilm formation. It is well known in many bacterial species that the quorum-sensing (QS) system regulates diverse functions such as biofilm formation. However, little is known about the QS system with autoinducers (AIs), between Veillonella and Streptococcus. Recently, AI-1 and AI-2 were detected and identified in the culture supernatants of V. tobetsuensis as strong signaling molecules in biofilm formation with S. gordonii. In particular, the supernatant from V. tobetsuensis showed the highest AI-2 activity among 6 oral Veillonella species, indicating that AIs, mainly AI-2, produced by V. tobetsuensis may be important factors and may facilitate biofilm formation of S. gordonii. Clarifying the mechanism that underlies the QS system between S. gordonii and V. tobetsuensis may lead to the development of novel methods for the prevention of oral infectious diseases caused by oral biofilms.
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19
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Fiedler T, Köller T, Kreikemeyer B. Streptococcus pyogenes biofilms-formation, biology, and clinical relevance. Front Cell Infect Microbiol 2015; 5:15. [PMID: 25717441 PMCID: PMC4324238 DOI: 10.3389/fcimb.2015.00015] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 01/26/2015] [Indexed: 12/31/2022] Open
Abstract
Streptococcus pyogenes (group A streptococci, GAS) is an exclusive human bacterial pathogen. The virulence potential of this species is tremendous. Interactions with humans range from asymptomatic carriage over mild and superficial infections of skin and mucosal membranes up to systemic purulent toxic-invasive disease manifestations. Particularly the latter are a severe threat for predisposed patients and lead to significant death tolls worldwide. This places GAS among the most important Gram-positive bacterial pathogens. Many recent reviews have highlighted the GAS repertoire of virulence factors, regulators and regulatory circuits/networks that enable GAS to colonize the host and to deal with all levels of the host immune defense. This covers in vitro and in vivo studies, including animal infection studies based on mice and more relevant, macaque monkeys. It is now appreciated that GAS, like many other bacterial species, do not necessarily exclusively live in a planktonic lifestyle. GAS is capable of microcolony and biofilm formation on host cells and tissues. We are now beginning to understand that this feature significantly contributes to GAS pathogenesis. In this review we will discuss the current knowledge on GAS biofilm formation, the biofilm-phenotype associated virulence factors, regulatory aspects of biofilm formation, the clinical relevance, and finally contemporary treatment regimens and future treatment options.
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Affiliation(s)
- Tomas Fiedler
- Institute of Medical Microbiology, Virology, and Hygiene, Rostock University Medical Centre Rostock, Germany
| | - Thomas Köller
- Institute of Medical Microbiology, Virology, and Hygiene, Rostock University Medical Centre Rostock, Germany
| | - Bernd Kreikemeyer
- Institute of Medical Microbiology, Virology, and Hygiene, Rostock University Medical Centre Rostock, Germany
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20
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Jimenez JC, Federle MJ. Quorum sensing in group A Streptococcus. Front Cell Infect Microbiol 2014; 4:127. [PMID: 25309879 PMCID: PMC4162386 DOI: 10.3389/fcimb.2014.00127] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 08/26/2014] [Indexed: 01/05/2023] Open
Abstract
Quorum sensing (QS) is a widespread phenomenon in the microbial world that has important implications in the coordination of population-wide responses in several bacterial pathogens. In Group A Streptococcus (GAS), many questions surrounding QS systems remain to be solved pertaining to their function and their contribution to the GAS lifestyle in the host. The QS systems of GAS described to date can be categorized into four groups: regulator gene of glucosyltransferase (Rgg), Sil, lantibiotic systems, and LuxS/AI-2. The Rgg family of proteins, a conserved group of transcription factors that modify their activity in response to signaling peptides, has been shown to regulate genes involved in virulence, biofilm formation and competence. The sil locus, whose expression is regulated by the activity of signaling peptides and a putative two-component system (TCS), has been implicated on regulating genes involved with invasive disease in GAS isolates. Lantibiotic regulatory systems are involved in the production of bacteriocins and their autoregulation, and some of these genes have been shown to target both bacterial organisms as well as processes of survival inside the infected host. Finally AI-2 (dihydroxy pentanedione, DPD), synthesized by the LuxS enzyme in several bacteria including GAS, has been proposed to be a universal bacterial communication molecule. In this review we discuss the mechanisms of these four systems, the putative functions of their targets, and pose critical questions for future studies.
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Affiliation(s)
- Juan Cristobal Jimenez
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago Chicago, IL, USA
| | - Michael J Federle
- Department of Medicinal Chemistry and Pharmacognosy, Center for Pharmaceutical Biotechnology, College of Pharmacy, University of Illinois at Chicago Chicago, IL, USA
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Bozue J, Powell BS, Cote CK, Moody KL, Gelhaus HC, Vietri NJ, Rozak DA. Disrupting the luxS quorum sensing gene does not significantly affect Bacillus anthracis virulence in mice or guinea pigs. Virulence 2012; 3:504-9. [PMID: 23076278 PMCID: PMC3524149 DOI: 10.4161/viru.21934] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Many bacterial species use secreted quorum-sensing autoinducer molecules to regulate cell density- and growth phase-dependent gene expression, including virulence factor production, as sufficient environmental autoinducer concentrations are achieved. Bacillus anthracis, the causative agent of anthrax, contains a functional autoinducer (AI-2) system, which appears to regulate virulence gene expression. To determine if the AI-2 system is necessary for disease, we constructed a LuxS AI-2 synthase-deficient mutant in the virulent Ames strain of B. anthracis. We found that growth of the LuxS-deficient mutant was inhibited and sporulation was delayed when compared with the parental strain. However, spores of the Ames luxS mutant remained fully virulent in both mice and guinea pigs.
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Affiliation(s)
- Joel Bozue
- The United States Army of Medical Research Institute of Infectious Diseases, Fort Detrick, MD, USA.
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22
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Redanz S, Standar K, Podbielski A, Kreikemeyer B. Heterologous expression of sahH reveals that biofilm formation is autoinducer-2-independent in Streptococcus sanguinis but is associated with an intact activated methionine cycle. J Biol Chem 2012; 287:36111-22. [PMID: 22942290 DOI: 10.1074/jbc.m112.379230] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Numerous studies have claimed deleterious effects of LuxS mutation on many bacterial phenotypes, including bacterial biofilm formation. Genetic complementation mostly restored the observed mutant phenotypes to WT levels, leading to the postulation that quorum sensing via a family of molecules generically termed autoinducer-2 (AI-2) is essential for many phenotypes. Because LuxS mutation has dual effects, this hypothesis needs to be investigated into the details for each bacterial species. In this study we used S. sanguinis SK36 as a model biofilm bacterium and employed physiological characterization and transcriptome approaches on WT and luxS-deficient strains, in combination with chemical, luxS, and sahH complementation experiments. SahH enables a direct conversion of SAH to homocysteine and thereby restores the activated methionine cycle in a luxS-negative background without formation of the AI-2 precursor 4,5-dihydroxy-2,3-pentanedione. With this strategy we were able to dissect the individual contribution of LuxS and AI-2 activity in detail. Our data revealed that S. sanguinis biofilm formation is independent from AI-2 substance pools and is rather supported by an intact activated methyl cycle. Of 216 differentially transcribed genes in the luxS mutant, 209 were restored by complementation with a gene encoding the S-adenosylhomocysteine hydrolase. Only nine genes, mainly involved in natural competence, were directly affected by the AI-2 quorum-sensing substance pool. Cumulatively, this suggested that biofilm formation in S. sanguinis is not under control of AI-2. Our study suggests that previously evaluated LuxS mutants in other species need to be revisited to resolve the precise contribution of AI-2 substance pools and the methionine pathways.
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Affiliation(s)
- Sylvio Redanz
- Institute of Medical Microbiology, Virology and Hygiene, Rostock University Hospital, 18057 Rostock, Germany
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Choi J, Shin D, Kim M, Park J, Lim S, Ryu S. LsrR-mediated quorum sensing controls invasiveness of Salmonella typhimurium by regulating SPI-1 and flagella genes. PLoS One 2012; 7:e37059. [PMID: 22623980 PMCID: PMC3356404 DOI: 10.1371/journal.pone.0037059] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 04/12/2012] [Indexed: 12/20/2022] Open
Abstract
Bacterial cell-to-cell communication, termed quorum sensing (QS), controls bacterial behavior by using various signal molecules. Despite the fact that the LuxS/autoinducer-2 (AI-2) QS system is necessary for normal expression of Salmonella pathogenicity island-1 (SPI-1), the mechanism remains unknown. Here, we report that the LsrR protein, a transcriptional regulator known to be involved in LuxS/AI-2-mediated QS, is also associated with the regulation of SPI-1-mediated Salmonella virulence. We determined that LsrR negatively controls SPI-1 and flagella gene expressions. As phosphorylated AI-2 binds to and inactivates LsrR, LsrR remains active and decreases expression of SPI-1 and flagella genes in the luxS mutant. The reduced expression of those genes resulted in impaired invasion of Salmonella into epithelial cells. Expression of SPI-1 and flagella genes was also reduced by overexpression of the LsrR regulator from a plasmid, but was relieved by exogenous AI-2, which binds to and inactivates LsrR. These results imply that LsrR plays an important role in selecting infectious niche of Salmonella in QS dependent mode.
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Affiliation(s)
- Jeongjoon Choi
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Agricultural Biomaterials, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Korea
| | - Dongwoo Shin
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Minjeong Kim
- Radiation Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, Korea
| | - Joowon Park
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Agricultural Biomaterials, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Korea
| | - Sangyong Lim
- Radiation Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, Korea
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Agricultural Biomaterials, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Korea
- * E-mail:
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Bandara HMHN, Lam OLT, Jin LJ, Samaranayake L. Microbial chemical signaling: a current perspective. Crit Rev Microbiol 2012; 38:217-49. [PMID: 22300377 DOI: 10.3109/1040841x.2011.652065] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Communication among microorganisms is mediated through quorum sensing. The latter is defined as cell-density linked, coordinated gene expression in microbial populations as a response to threshold signal concentrations followed by induction of a synchronized population response. This phenomenon is used by a variety of microbes to optimize their survival in a constantly challenging, dynamic milieu, by correlating individual cellular functions to community-based requirements. The synthesis, secretion, and perception of quorum-sensing molecules and their target response play a pivotal role in quorum sensing and are tightly controlled by complex, multilayered and interconnected signal transduction pathways that regulate diverse cellular functions. Quorum sensing exemplifies interactive social behavior innate to the microbial world that controls features such as, virulence, biofilm maturation, antibiotic resistance, swarming motility, and conjugal plasmid transfer. Over the past two decades, studies have been performed to rationalize bacterial cell-to-cell communication mediated by structurally and functionally diverse small molecules. This review describes the theoretical aspects of cellular and quorum-sensing mechanisms that affect microbial physiology and pathobiology.
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Affiliation(s)
- H M H N Bandara
- Oral Biosciences, Prince Philip Dental Hospital, 34, Hospital Road, Sai Ying Pun, Hong Kong
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25
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Patenge N, Fiedler T, Kreikemeyer B. Common regulators of virulence in streptococci. Curr Top Microbiol Immunol 2012; 368:111-53. [PMID: 23242855 DOI: 10.1007/82_2012_295] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Streptococcal species are a diverse group of bacteria which can be found in animals and humans. Their interactions with host organisms can vary from commensal to pathogenic. Many of the pathogenic species are causative agents of severe, invasive infections in their hosts, accounting for a high burden of morbidity and mortality, associated with high economic costs in industry and health care. Among them, Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus pneumoniae, and Streptococcus suis are discussed here. An environmentally stimulated and tightly controlled expression of their virulence factors is of utmost importance for their pathogenic potential. Thus, the most universal and widespread regulators from the classes of stand-alone transcriptional regulators, two-component signal transduction systems (TCS), eukaryotic-like serine/threonine kinases, and small noncoding RNAs are the topic of this chapter. The regulatory levels are reviewed with respect to function, activity, and their role in pathogenesis. Understanding of and interfering with transcriptional regulation mechanisms and networks is a promising basis for the development of novel anti-infective therapies.
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Affiliation(s)
- Nadja Patenge
- Institute of Medical Microbiology, Virology and Hygiene, University Medicine Rostock, Schillingallee 70, 18057 Rostock, Germany
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Chiang-Ni C, Zheng PX, Tsai PJ, Chuang WJ, Lin YS, Liu CC, Wu JJ. Environmental pH changes, but not the LuxS signalling pathway, regulate SpeB expression in M1 group A streptococci. J Med Microbiol 2011; 61:16-22. [PMID: 21890514 DOI: 10.1099/jmm.0.036012-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The autoinducer-2/LuxS signalling pathway participates in quorum sensing in diverse bacterial species. In group A streptococci (GAS), LuxS has been shown to be involved in regulating the expression of several important virulence factors. Streptococcal pyrogenic exotoxin B (SpeB), a cysteine protease that has important roles in GAS pathogenesis, is positively regulated by LuxS in M3 and M5 strains. In the present study, it was found that the supernatant harvested from an overnight culture stimulated M1 strains to express speB. However, mutation of the luxS gene in M1 strains or treating M1 strains with luxS mutant culture supernatant did not affect speB expression, indicating that the LuxS pathway is not involved in regulation of speB expression in M1 strains. In addition, the acid property of culture broth was found to be able to stimulate M1 strains to express speB in the same LuxS-independent manner. These results indicate that speB expression in M1 strains is induced by environmental pH changes but is not regulated by the LuxS signalling pathway.
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Affiliation(s)
- Chuan Chiang-Ni
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC
| | - Po-Xing Zheng
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC
| | - Pei-Jane Tsai
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC
| | - Woei-Jer Chuang
- Department of Biochemistry, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC
| | - Yee-Shin Lin
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC
| | - Ching-Chuan Liu
- Department of Pediatrics, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC
| | - Jiunn-Jong Wu
- Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan, ROC.,Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC
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Carroll RK, Musser JM. From transcription to activation: how group A streptococcus, the flesh-eating pathogen, regulates SpeB cysteine protease production. Mol Microbiol 2011; 81:588-601. [PMID: 21707787 DOI: 10.1111/j.1365-2958.2011.07709.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Streptococcal pyrogenic exotoxin B (SpeB) is a protease secreted by group A streptococci and known to degrade a wide range of host and GAS proteins in vitro. Although the role of SpeB in GAS infection is debated, recent evidence has conclusively demonstrated that SpeB is critical for the pathogenesis of severe invasive disease caused by GAS. Genetic inactivation of the speB gene results in significantly decreased virulence in a necrotizing fasciitis model of infection. Production of fully active SpeB by GAS is extremely complex. Following transcription and translation the SpeB protein is secreted as an inactive zymogen, which is autocatalytically processed through a series of intermediates to form an active protease. Each step from transcription to protease activation is tightly controlled and regulated by the bacterial cell reflecting the critical role played by this virulence factor in GAS infection. Here we review the molecular aspects of SpeB production by GAS from transcription to activation and the multiple layers of control involved.
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Affiliation(s)
- Ronan K Carroll
- Center for Molecular and Translational Human Infectious Diseases Research, The Methodist Hospital Research Institute, Houston, TX 77030, USA
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Parveen N, Cornell KA. Methylthioadenosine/S-adenosylhomocysteine nucleosidase, a critical enzyme for bacterial metabolism. Mol Microbiol 2010; 79:7-20. [PMID: 21166890 DOI: 10.1111/j.1365-2958.2010.07455.x] [Citation(s) in RCA: 184] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The importance of methylthioadenosine/S-adenosylhomocysteine (MTA/SAH) nucleosidase in bacteria has started to be appreciated only in the past decade. A comprehensive analysis of its various roles here demonstrates that it is an integral component of the activated methyl cycle, which recycles adenine and methionine through S-adenosylmethionine (SAM)-mediated methylation reactions, and also produces the universal quorum-sensing signal, autoinducer-2 (AI-2). SAM is also essential for synthesis of polyamines, N-acylhomoserine lactone (autoinducer-1), and production of vitamins and other biomolecules formed by SAM radical reactions. MTA, SAH and 5'-deoxyadenosine (5'dADO) are product inhibitors of these reactions, and are substrates of MTA/SAH nucleosidase, underscoring its importance in a wide array of metabolic reactions. Inhibition of this enzyme by certain substrate analogues also limits synthesis of autoinducers and hence causes reduction in biofilm formation and may attenuate virulence. Interestingly, the inhibitors of MTA/SAH nucleosidase are very effective against the Lyme disease causing spirochaete, Borrelia burgdorferi, which uniquely expresses three homologous functional enzymes. These results indicate that inhibition of this enzyme can affect growth of different bacteria by affecting different mechanisms. Therefore, new inhibitors are currently being explored for development of potential novel broad-spectrum antimicrobials.
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Affiliation(s)
- Nikhat Parveen
- Department of Microbiology and Molecular Genetics, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, 225 Warren Street, Newark, NJ 07103-3535, USA.
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Different aspects of bacterial communication signals. World J Microbiol Biotechnol 2010; 27:1267-80. [PMID: 25187126 DOI: 10.1007/s11274-010-0575-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 09/25/2010] [Indexed: 12/20/2022]
Abstract
The communication or quorum-sensing signal molecules (QSSM) are specialized molecules used by numerous gram-negative bacterial pathogens of animals and plants to regulate or modulate bacterial virulence factor production. In plant-associated bacteria, genes encoding the production of these signal molecules, QSSMs, were discovered to be linked with the phenotype of bacterium, because mutation of these genes typically disrupts some behaviors of bacteria. There are other regulator genes which respond to the presence of signal molecule and regulate the production of signal molecule as well as some virulence factors. The synthesis and regulator genes (collectively called quorum-sensing genes hereafter) are repressed in low bacterial population but induced when bacteria reach to high cell density. Multiple regulatory components have been identified in the bacteria that are under control of quorum sensing. This review describes different communication signal molecules, and the various chemical, physical and genomic factors known to synthesize signals. Likewise, the role of some signal-degrading enzymes or compounds and the interaction of QSSMs with eukaryotic metabolism will be discussed here.
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The secreted esterase of group a streptococcus is important for invasive skin infection and dissemination in mice. Infect Immun 2009; 77:5225-32. [PMID: 19805529 DOI: 10.1128/iai.00636-09] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Virulence factors regulated by the CovRS/CsrRS two-component gene regulatory system contribute to the invasive diseases caused by group A Streptococcus (GAS). To determine whether the streptococcal secreted esterase (Sse), an antigen that protects against subcutaneous GAS infection, is one of these virulence factors, we investigated the phenotype of a nonpolar sse deletion mutant strain (Deltasse). In addition, we examined the effects of covS mutation on sse expression. As assessed using a mouse model of subcutaneous infection, the virulence of the Deltasse strain is attenuated and the overall pathology is reduced. Furthermore, GAS was detected in the blood and spleens from mice subcutaneously infected with the parental strain, whereas mice subcutaneously infected with the Deltasse strain had no GAS present in their blood and spleens. The ability of the mutant to survive in the subcutis of mice appeared to be compromised. The growth of the Deltasse strain in rich and chemically defined media and nonimmune human blood and sera was slower than that of the wild-type strain. Complementation restored the phenotype of the Deltasse strain to that of the wild-type strain. The wild-type, Deltasse, and complement strains had no detectable SpeB activity. Expression of Sse is negatively controlled by CovRS. These findings suggest that Sse is a CovRS-regulated virulence factor that is important for the virulence of GAS in subcutaneous infection and plays an important role in severe soft tissue infections and systemic dissemination of GAS from the skin.
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Russell HH, Zhou L, Sriskandan S. Rapid screen for epithelial internalization of Tn917-mutagenized Streptococcus pyogenes. J Microbiol Methods 2009; 78:34-9. [PMID: 19371765 DOI: 10.1016/j.mimet.2009.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 04/03/2009] [Accepted: 04/06/2009] [Indexed: 10/20/2022]
Abstract
Group A streptococci (GAS) cause a number of human diseases ranging from pharyngitis to necrotizing fasciitis. GAS are hypothesized to escape killing by either the immune system or beta lactam antibiotics by internalization into epithelial cells. A Tn917 library of transposon mutants was screened for capacity to invade and survive in human epithelial cells using a novel blood agar overlay method. Although the screen revealed that a majority of Tn917 insertions occurred within a 10 kb region of the genome, GAS genes identified as essential for internalization into epithelial cells included ABC transporters, and DNA maintenance proteins, and citrate metabolism enzymes, underlining the importance of adaptation to the intracellular environment.
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Affiliation(s)
- Hugh H Russell
- Department of Infectious Diseases & Immunity, Hammersmith Campus, Imperial College London, UK
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Campylobacter jejuni cocultured with epithelial cells reduces surface capsular polysaccharide expression. Infect Immun 2009; 77:1959-67. [PMID: 19273563 DOI: 10.1128/iai.01239-08] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The host cell environment can alter bacterial pathogenicity. We employed a combination of cellular and molecular techniques to study the expression of Campylobacter jejuni polysaccharides cocultured with HCT-8 epithelial cells. After two passages, the amount of membrane-bound high-molecular-weight polysaccharide was considerably reduced. Microarray profiling confirmed significant downregulation of capsular polysaccharide (CPS) locus genes. Experiments using conditioned media showed that sugar depletion occurred only when the bacterial and epithelial cells were cocultured. CPS depletion occurred when C. jejuni organisms were exposed to conditioned media from a different C. jejuni strain but not when exposed to conditioned media from other bacterial species. Proteinase K or heat treatment of conditioned media under coculture conditions abrogated the effect on the sugars, as did formaldehyde fixation and cycloheximide treatment of host cells or chloramphenicol treatment of the bacteria. However, sugar depletion was not affected in flagellar export (fliQ) and quorum-sensing (luxS) gene mutants. Passaged C. jejuni showed reduced invasiveness and increased serum sensitivity in vitro. C. jejuni alters its surface polysaccharides when cocultured with epithelial cells, suggesting the existence of a cross talk mechanism that modulates CPS expression during infection.
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Hollands A, Aziz RK, Kansal R, Kotb M, Nizet V, Walker MJ. A naturally occurring mutation in ropB suppresses SpeB expression and reduces M1T1 group A streptococcal systemic virulence. PLoS One 2008; 3:e4102. [PMID: 19116661 PMCID: PMC2605554 DOI: 10.1371/journal.pone.0004102] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Accepted: 11/21/2008] [Indexed: 11/18/2022] Open
Abstract
Epidemiological studies of group A streptococcus (GAS) have noted an inverse relationship between SpeB expression and invasive disease. However, the role of SpeB in the course of infection is still unclear. In this study we utilize a SpeB-negative M1T1 clinical isolate, 5628, with a naturally occurring mutation in the gene encoding the regulator RopB, to elucidate the role of RopB and SpeB in systemic virulence. Allelic exchange mutagenesis was used to replace the mutated ropB allele in 5628 with the intact allele from the well characterized isolate 5448. The inverse allelic exchange was also performed to replace the intact ropB in 5448 with the mutated allele from 5628. An intact ropB was found to be essential for SpeB expression. While the ropB mutation was shown to have no effect on hemolysis of RBC's, extracellular DNase activity or survival in the presence of neutrophils, strains with the mutated ropB allele were less virulent in murine systemic models of infection. An isogenic SpeB knockout strain containing an intact RopB showed similarly reduced virulence. Microarray analysis found genes of the SpeB operon to be the primary target of RopB regulation. These data show that an intact RopB and efficient SpeB production are necessary for systemic infection with GAS.
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Affiliation(s)
- Andrew Hollands
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales, Australia
- The Department of Molecular Genetics, Biochemistry and Microbiology, The University of Cincinnati, College of Medicine, Cincinnati, Ohio, United States of America
| | - Ramy K. Aziz
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Rita Kansal
- The VA Hospital, Memphis, Tennessee, United States of America
| | - Malak Kotb
- The VA Hospital, Memphis, Tennessee, United States of America
- The Department of Molecular Genetics, Biochemistry and Microbiology, The University of Cincinnati, College of Medicine, Cincinnati, Ohio, United States of America
| | - Victor Nizet
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States of America
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Mark J. Walker
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales, Australia
- * E-mail:
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Siller M, Janapatla RP, Pirzada ZA, Hassler C, Zinkl D, Charpentier E. Functional analysis of the group A streptococcal luxS/AI-2 system in metabolism, adaptation to stress and interaction with host cells. BMC Microbiol 2008; 8:188. [PMID: 18973658 PMCID: PMC2603038 DOI: 10.1186/1471-2180-8-188] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Accepted: 10/30/2008] [Indexed: 01/03/2023] Open
Abstract
Background The luxS/AI-2 signaling pathway has been reported to interfere with important physiological and pathogenic functions in a variety of bacteria. In the present study, we investigated the functional role of the streptococcal luxS/AI-2 system in metabolism and diverse aspects of pathogenicity including the adaptation of the organism to stress conditions using two serotypes of Streptococcus pyogenes, M1 and M19. Results Exposing wild-type and isogenic luxS-deficient strains to sulfur-limited media suggested a limited role for luxS in streptococcal activated methyl cycle metabolism. Interestingly, loss of luxS led to an increased acid tolerance in both serotypes. Accordingly, luxS expression and AI-2 production were reduced at lower pH, thus linking the luxS/AI-2 system to stress adaptation in S. pyogenes. luxS expression and AI-2 production also decreased when cells were grown in RPMI medium supplemented with 10% serum, considered to be a host environment-mimicking medium. Furthermore, interaction analysis with epithelial cells and macrophages showed a clear advantage of the luxS-deficient mutants to be internalized and survive intracellularly in the host cells compared to the wild-type parents. In addition, our data revealed that luxS influences the expression of two virulence-associated factors, the fasX regulatory RNA and the virulence gene sibA (psp). Conclusion Here, we suggest that the group A streptococcal luxS/AI-2 system is not only involved in the regulation of virulence factor expression but in addition low level of luxS expression seems to provide an advantage for bacterial survival in conditions that can be encountered during infections.
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Affiliation(s)
- Maria Siller
- University of Vienna, Department of Microbiology and Immunobiology, 1030 Vienna, Austria.
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Rezzonico F, Duffy B. Lack of genomic evidence of AI-2 receptors suggests a non-quorum sensing role for luxS in most bacteria. BMC Microbiol 2008; 8:154. [PMID: 18803868 PMCID: PMC2561040 DOI: 10.1186/1471-2180-8-154] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Accepted: 09/20/2008] [Indexed: 01/08/2023] Open
Abstract
Background Great excitement accompanied discoveries over the last decade in several Gram-negative and Gram-positive bacteria of the LuxS protein, which catalyzes production of the AI-2 autoinducer molecule for a second quorum sensing system (QS-2). Since the luxS gene was found to be widespread among the most diverse bacterial taxa, it was hypothesized that AI-2 may constitute the basis of a universal microbial language, a kind of bacterial Esperanto. Many of the studies published in this field have drawn a direct correlation between the occurrence of the luxS gene in a given organism and the presence and functionality of a QS-2 therein. However, rarely hathe existence of potential AI-2 receptors been examined. This is important, since it is now well recognized that LuxS also holds a central role as a metabolic enzyme in the activated methyl cycle which is responsible for the generation of S-adenosyl-L-methionine, the major methyl donor in the cell. Results In order to assess whether the role of LuxS in these bacteria is indeed related to AI-2 mediated quorum sensing we analyzed genomic databases searching for established AI-2 receptors (i.e., LuxPQ-receptor of Vibrio harveyi and Lsr ABC-transporter of Salmonella typhimurium) and other presumed QS-related proteins and compared the outcome with published results about the role of QS-2 in these organisms. An unequivocal AI-2 related behavior was restricted primarily to organisms bearing known AI-2 receptor genes, while phenotypes of luxS mutant bacteria lacking these genes could often be explained simply by assuming deficiencies in sulfur metabolism. Conclusion Genomic analysis shows that while LuxPQ is restricted to Vibrionales, the Lsr-receptor complex is mainly present in pathogenic bacteria associated with endotherms. This suggests that QS-2 may play an important role in interactions with animal hosts. In most other species, however, the role of LuxS appears to be limited to metabolism, although in a few cases the presence of yet unknown receptors or the adaptation of pre-existent effectors to QS-2 must be postulated.
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Affiliation(s)
- Fabio Rezzonico
- Agroscope Changins-Wädenswil ACW, Division of Plant Protection, CH-8820 Wädenswil, Switzerland.
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36
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Zhang M, Sun K, Sun L. Regulation of autoinducer 2 production and luxS expression in a pathogenic Edwardsiella tarda strain. Microbiology (Reading) 2008; 154:2060-2069. [DOI: 10.1099/mic.0.2008/017343-0] [Citation(s) in RCA: 168] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Min Zhang
- Graduate University of the Chinese Academy of Sciences, Beijing 100049, PR China
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China
| | - Kun Sun
- Graduate University of the Chinese Academy of Sciences, Beijing 100049, PR China
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China
| | - Li Sun
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China
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Choi J, Shin D, Ryu S. Implication of quorum sensing in Salmonella enterica serovar typhimurium virulence: the luxS gene is necessary for expression of genes in pathogenicity island 1. Infect Immun 2007; 75:4885-90. [PMID: 17620352 PMCID: PMC2044537 DOI: 10.1128/iai.01942-06] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Despite the fact that the regulatory system sensing density of cell population and its signaling molecule have been identified in Salmonella enterica, the biological significance of this phenomenon termed as quorum sensing remains unknown. In this report, we provide evidence that the luxS gene is necessary for Salmonella virulence phenotypes. Transcription assays showed that the cell-density-dependent induction of the invF gene was abolished in a Salmonella strain with the luxS gene deleted. The effect of the luxS deletion was also investigated in other InvF-regulated genes expressed from Salmonella pathogenicity island 1 (SPI-1). The decreased expression of SPI-1 genes in the strain with luxS deleted could be restored by either the addition of a synthetic signal molecule or the introduction of a plasmid copy of the luxS gene. Thus, the reduced expression of invF and its regulated genes in Salmonella cells lacking quorum sensing resulted in the attenuation of virulence phenotypes both in vitro and in vivo.
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Affiliation(s)
- Jeongjoon Choi
- Department of Food and Animal Biotechnology, School of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea
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38
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Sela S, Frank S, Belausov E, Pinto R. A Mutation in the luxS gene influences Listeria monocytogenes biofilm formation. Appl Environ Microbiol 2006; 72:5653-8. [PMID: 16885324 PMCID: PMC1538747 DOI: 10.1128/aem.00048-06] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Accepted: 06/01/2006] [Indexed: 12/25/2022] Open
Abstract
Using a Vibrio harveyi reporter strain, we demonstrated that Listeria monocytogenes secretes a functional autoinducer 2 (AI-2)-like signal. A luxS-deficient mutant produced a denser biofilm and attached to a glass surface 19-fold better than the parent strain. Exogenous AI-2 failed to restore the wild-type phenotype to the mutant. It seems that an intact luxS gene is associated with repression of components required for attachment and biofilm formation.
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Affiliation(s)
- Shlomo Sela
- Microbial Food-Safety Research Unit, Department of Food Sciences, Institute for Technology and Storage of Fresh Produce, Agricultural Research Organization (ARO), The Volcani Center, Beth-Dagan 50250, Israel.
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Lombardía E, Rovetto AJ, Arabolaza AL, Grau RR. A LuxS-dependent cell-to-cell language regulates social behavior and development in Bacillus subtilis. J Bacteriol 2006; 188:4442-52. [PMID: 16740951 PMCID: PMC1482974 DOI: 10.1128/jb.00165-06] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Cell-to-cell communication in bacteria is mediated by quorum-sensing systems (QSS) that produce chemical signal molecules called autoinducers (AI). In particular, LuxS/AI-2-dependent QSS has been proposed to act as a universal lexicon that mediates intra- and interspecific bacterial behavior. Here we report that the model organism Bacillus subtilis operates a luxS-dependent QSS that regulates its morphogenesis and social behavior. We demonstrated that B. subtilis luxS is a growth-phase-regulated gene that produces active AI-2 able to mediate the interspecific activation of light production in Vibrio harveyi. We demonstrated that in B. subtilis, luxS expression was under the control of a novel AI-2-dependent negative regulatory feedback loop that indicated an important role for AI-2 as a signaling molecule. Even though luxS did not affect spore development, AI-2 production was negatively regulated by the master regulatory proteins of pluricellular behavior, SinR and Spo0A. Interestingly, wild B. subtilis cells, from the undomesticated and probiotic B. subtilis natto strain, required the LuxS-dependent QSS to form robust and differentiated biofilms and also to swarm on solid surfaces. Furthermore, LuxS activity was required for the formation of sophisticated aerial colonies that behaved as giant fruiting bodies where AI-2 production and spore morphogenesis were spatially regulated at different sites of the developing colony. We proposed that LuxS/AI-2 constitutes a novel form of quorum-sensing regulation where AI-2 behaves as a morphogen-like molecule that coordinates the social and pluricellular behavior of B. subtilis.
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Affiliation(s)
- Esteban Lombardía
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario (2000), Argentina
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Parveen N, Cornell KA, Bono JL, Chamberland C, Rosa P, Leong JM. Bgp, a secreted glycosaminoglycan-binding protein of Borrelia burgdorferi strain N40, displays nucleosidase activity and is not essential for infection of immunodeficient mice. Infect Immun 2006; 74:3016-20. [PMID: 16622242 PMCID: PMC1459710 DOI: 10.1128/iai.74.5.3016-3020.2006] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Bgp, one of the surface-localized glycosaminoglycan-binding proteins of the Lyme disease spirochete, Borrelia burgdorferi, exhibited nucleosidase activity. Infection of SCID mice with B. burgdorferi strain N40 mutants harboring a targeted insertion in bgp and apparently retaining all endogenous plasmids revealed that Bgp is not essential for colonization of immunocompromised mice.
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Affiliation(s)
- Nikhat Parveen
- Department of Microbiology and Molecular Genetics, ICPH Building, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ 07103-2714, USA.
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Romao S, Memmi G, Oggioni MR, Trombe MC. LuxS impacts on LytA-dependent autolysis and on competence in Streptococcus pneumoniae. Microbiology (Reading) 2006; 152:333-341. [PMID: 16436421 DOI: 10.1099/mic.0.28406-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The ubiquitous protein LuxS with S-ribosylhomocysteinase activity is involved in S-adenosyl methionine detoxification, C-1 unit recycling and the production of autoinducers that allow the cell to sense and respond to cell density. Independent reports describe the impact of LuxS deficiency on Streptococcus pneumoniae virulence in the mouse. In vitro, LuxS deficiency confers discrete phenotypes. A combined approach using genetic dissection and mixed-culture experiments allowed the involvement of LuxS in the developmental physiology of S. pneumoniae to be investigated. Functional LuxS was found to be related on the one hand to down-regulation of competence, and on the other hand to attenuation of autolysis in cultures entering stationary phase. The competence phenotype of luxS mutant bacteria was complemented by media conditioned by competence-defective ComAB0 bacteria, but not by BSA. The autolytic phenotype was complemented by BSA, but not by conditioned supernatants. It is suggested that the impact of LuxS on competence, but not on autolysis, involves cell–cell communication. The phenotype of luxS mutant strains reveals a hierarchy in the competence regulatory networks of S. pneumoniae.
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Affiliation(s)
- Susana Romao
- Interactions et Signalisation Cellulaires: Relation Hôte-Pathogène, EA3036, IFR31, CHU Rangueil, Université Paul Sabatier, 31403 Toulouse, France
| | - Guido Memmi
- Laboratorio di Microbiologia Molecolare e Biotecnologia, Dipartimento di Biologia Molecolare, Università di Siena, Siena, Italy
| | - Marco R Oggioni
- UOC Batteriologia, Azienda Ospedaliera Universitaria Senese, Siena, Italy
- Laboratorio di Microbiologia Molecolare e Biotecnologia, Dipartimento di Biologia Molecolare, Università di Siena, Siena, Italy
| | - Marie-Claude Trombe
- Interactions et Signalisation Cellulaires: Relation Hôte-Pathogène, EA3036, IFR31, CHU Rangueil, Université Paul Sabatier, 31403 Toulouse, France
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Daines DA, Bothwell M, Furrer J, Unrath W, Nelson K, Jarisch J, Melrose N, Greiner L, Apicella M, Smith AL. Haemophilus influenzae luxS mutants form a biofilm and have increased virulence. Microb Pathog 2005; 39:87-96. [PMID: 16099134 DOI: 10.1016/j.micpath.2005.06.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2004] [Revised: 05/23/2005] [Accepted: 06/20/2005] [Indexed: 01/22/2023]
Abstract
To gain insight into the role of luxSHi in disease pathogenesis, we inactivated that gene in several non-typeable Haemophilus influenzae isolates with an antibiotic resistance cassette. Gene inactivation was confirmed by PCR and by Southern blot analysis in each strain. Culture filtrates from luxSHi mutants contained a decreased amount of autoinducer-2 (AI-2) activity in comparison to the wild-type isolates using the Vibrio harveyi BB170 bioassay. Culture filtrates from Escherichia coli strain DH5alpha expressing a cloned luxSHi contained 350-fold more AI-2 activity per cell than E. coli DH5alpha containing the vector alone. The growth rate in several liquid media, and the cell density after overnight growth were not significantly different between the parents and the luxSHi mutants. Two clinical H. influenzae and their luxSHi mutants produced an identical biofilm in a flow system. Invasion of human cells by the luxSHi mutants, in comparison to the wild-type parents was strain-dependent, and cell type-dependent, but the luxSHi mutants tended to be more invasive. The luxSHi mutant of an otitis media isolate, strain R3157 appeared more virulent in the chinchilla model of otitis media: there were more bacteria in the middle ear, a greater inflammatory response and more goblet cell hyperplasia 10 days after the inoculation. We conclude that the H. influenzae homologue of luxS modulates certain virulence traits.
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Affiliation(s)
- Dayle A Daines
- Section on Microbial Pathogens, Seattle Biomedical Research Institute, 307 Westlake Ave North, Suite 500, Seattle, WA 98109-5219, USA
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Sperandio B, Polard P, Ehrlich DS, Renault P, Guédon E. Sulfur amino acid metabolism and its control in Lactococcus lactis IL1403. J Bacteriol 2005; 187:3762-78. [PMID: 15901700 PMCID: PMC1112055 DOI: 10.1128/jb.187.11.3762-3778.2005] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cysteine and methionine availability influences many processes in the cell. In bacteria, transcription of the specific genes involved in the synthesis of these two amino acids is usually regulated by different mechanisms or regulators. Pathways for the synthesis of cysteine and methionine and their interconversion were experimentally determined for Lactococcus lactis, a lactic acid bacterium commonly found in food. A new gene, yhcE, was shown to be involved in methionine recycling to cysteine. Surprisingly, 18 genes, representing almost all genes of these pathways, are under the control of a LysR-type activator, FhuR, also named CmbR. DNA microarray experiments showed that FhuR targets are restricted to this set of 18 genes clustered in seven transcriptional units, while cysteine starvation modifies the transcription level of several other genes potentially involved in oxidoreduction processes. Purified FhuR binds a 13-bp box centered 46 to 53 bp upstream of the transcriptional starts from the seven regulated promoters, while a second box with the same consensus is present upstream of the first binding box, separated by 8 to 10 bp. O-Acetyl serine increases FhuR binding affinity to its binding boxes. The overall view of sulfur amino acid metabolism and its regulation in L. lactis indicates that CysE could be a master enzyme controlling the activity of FhuR by providing its effector, while other controls at the enzymatic level appear to be necessary to compensate the absence of differential regulation of the genes involved in the interconversion of methionine and cysteine and other biosynthesis genes.
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Affiliation(s)
- Brice Sperandio
- Génétique Microbienne, Institut National de la Recherche Agronomique, 78352 Jouy-en-Josas cedex, France
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Kagawa TF, O'toole PW, Cooney JC. SpeB-Spi: a novel protease-inhibitor pair from Streptococcus pyogenes. Mol Microbiol 2005; 57:650-66. [PMID: 16045611 DOI: 10.1111/j.1365-2958.2005.04708.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This study presents evidence for a novel protease-protease inhibitor couple, SpeB-Spi, in the human pathogen Streptococcus pyogenes. The gene for the inhibitor Spi is located directly downstream of the gene for the streptococcal cysteine protease SpeB. Spi is 37% identical and 70% similar to the sequence of the SpeB propeptide, suggesting that Spi and the SpeB propeptide might bind to SpeB in an analogous manner. Secondary structure predictions and molecular modelling suggested that Spi would adopt a structure similar to the SpeB propeptide. The spi gene was co-transcribed with speB on the 1.7 knt and 2.2 knt transcripts previously identified for speB. The Spi protein was purified by SpeB-affinity chromatography from the S. pyogenes cytoplasm. Recombinant Spi was produced and purified, and shown to bind to SpeB and to inhibit its protease activity. Although a similar genetic arrangement of protease and inhibitor is present in staphylococci, this is the first example of an inhibitor molecule that is a structural homologue of the cognate propeptide, and which is genetically linked to the protease gene. Thus, this represents a novel system whereby bacteria may control the intracellular activity of their proteases.
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Affiliation(s)
- Todd F Kagawa
- Department of Chemical and Environmental Sciences, and Materials and Surfaces Sciences Institute, University of Limerick, Limerick, Ireland
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Vendeville A, Winzer K, Heurlier K, Tang CM, Hardie KR. Making 'sense' of metabolism: autoinducer-2, LUXS and pathogenic bacteria. Nat Rev Microbiol 2005; 3:383-96. [PMID: 15864263 DOI: 10.1038/nrmicro1146] [Citation(s) in RCA: 435] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Bacteria exploit many mechanisms to communicate with each other and their surroundings. Mechanisms using small diffusible signals to coordinate behaviour with cell density (quorum sensing) frequently contribute to pathogenicity. However, pathogens must also be able to acquire nutrients and replicate to successfully invade their host. One quorum-sensing system, based on the possession of LuxS, bears the unique feature of contributing directly to metabolism, and therefore has the potential to influence both gene regulation and bacterial fitness. Here, we discuss the influence that LuxS and its product, autoinducer-2, have on virulence, relating the current evidence to the preferred niche of the pathogen and the underlying mechanisms involved.
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Affiliation(s)
- Agnès Vendeville
- Centre for Molecular Microbiology and Infection, Department of Infectious Diseases, Faculty of Medicine, Flowers Building, Armstrong Road, Imperial College London, London SW7 2AZ, UK
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Is autoinducer-2 a universal signal for interspecies communication: a comparative genomic and phylogenetic analysis of the synthesis and signal transduction pathways. BMC Evol Biol 2004; 4:36. [PMID: 15456522 PMCID: PMC524169 DOI: 10.1186/1471-2148-4-36] [Citation(s) in RCA: 182] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2004] [Accepted: 09/29/2004] [Indexed: 11/10/2022] Open
Abstract
Background Quorum sensing is a process of bacterial cell-to-cell communication involving the production and detection of extracellular signaling molecules called autoinducers. Recently, it has been proposed that autoinducer-2 (AI-2), a furanosyl borate diester derived from the recycling of S-adenosyl-homocysteine (SAH) to homocysteine, serves as a universal signal for interspecies communication. Results In this study, 138 completed genomes were examined for the genes involved in the synthesis and detection of AI-2. Except for some symbionts and parasites, all organisms have a pathway to recycle SAH, either using a two-step enzymatic conversion by the Pfs and LuxS enzymes or a one-step conversion using SAH-hydrolase (SahH). 51 organisms including most Gamma-, Beta-, and Epsilonproteobacteria, and Firmicutes possess the Pfs-LuxS pathway, while Archaea, Eukarya, Alphaproteobacteria, Actinobacteria and Cyanobacteria prefer the SahH pathway. In all 138 organisms, only the three Vibrio strains had strong, bidirectional matches to the periplasmic AI-2 binding protein LuxP and the central signal relay protein LuxU. The initial two-component sensor kinase protein LuxQ, and the terminal response regulator luxO are found in most Proteobacteria, as well as in some Firmicutes, often in several copies. Conclusions The genomic analysis indicates that the LuxS enzyme required for AI-2 synthesis is widespread in bacteria, while the periplasmic binding protein LuxP is only present in Vibrio strains. Thus, other organisms may either use components different from the AI-2 signal transduction system of Vibrio strains to sense the signal of AI-2, or they do not have such a quorum sensing system at all.
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