1
|
Liu S, Li D, Qin Z, Zeng W, Zhou J. Enhancing Glycosylation of Flavonoids by Engineering the Uridine Diphosphate Glucose Supply in Escherichia coli. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:17842-17851. [PMID: 37941337 DOI: 10.1021/acs.jafc.3c05264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
Abstract
Glycosylation can enhance the solubility and stability of flavonoids. The main limitation of the glycosylation process is low intracellular uridine diphosphate glucose (UDPG) availability. This study aimed to create a glycosylation platform strain in Escherichia coli BL21(DE3) by multiple metabolic engineering of the UDPG supply. Glycosyltransferase TcCGT1 was introduced to synthesize vitexin and orientin from apigenin and luteolin, respectively. To further expand this glycosylation platform strain, not only were UDP rhamnose and UDP galactose synthesis pathways constructed, but rhamnosyltransferase (GtfC) and galactosyltransferase (PhUGT) were also introduced, respectively. In a 5 L bioreactor with apigenin, luteolin, kaempferol, and quercetin as glycosyl acceptors, vitexin, orientin, afzelin, quercitrin, hyperoside, and trifolin glycosylation products reached 17.2, 36.5, 5.2, 14.1, 6.4, and 11.4 g/L, respectively, the highest titers reported to date for all. The platform strain has great potential for large-scale production of glycosylated flavonoids.
Collapse
Affiliation(s)
- Shike Liu
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
| | - Dong Li
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
| | - Zhijie Qin
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
| | - Weizhu Zeng
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
| | - Jingwen Zhou
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
| |
Collapse
|
2
|
Dehority W, Morley VJ, Domman DB, Daly SM, Triplett KD, Disch K, Varjabedian R, Yousey A, Mortaji P, Hill D, Oyebamiji O, Guo Y, Schwalm K, Hall PR, Dinwiddie D, Femling J. Genomic characterization of Staphylococcus aureus isolates causing osteoarticular infections in otherwise healthy children. PLoS One 2022; 17:e0272425. [PMID: 36037235 PMCID: PMC9423648 DOI: 10.1371/journal.pone.0272425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 07/19/2022] [Indexed: 12/03/2022] Open
Abstract
Background Pediatric osteoarticular infections are commonly caused by Staphylococcus aureus. The contribution of S. aureus genomic variability to pathogenesis of these infections is poorly described. Methods We prospectively enrolled 47 children over 3 1/2 years from whom S. aureus was isolated on culture—12 uninfected with skin colonization, 16 with skin abscesses, 19 with osteoarticular infections (four with septic arthritis, three with acute osteomyelitis, six with acute osteomyelitis and septic arthritis and six with chronic osteomyelitis). Isolates underwent whole genome sequencing, with assessment for 254 virulence genes and any mutations as well as creation of a phylogenetic tree. Finally, isolates were compared for their ability to form static biofilms and compared to the genetic analysis. Results No sequence types predominated amongst osteoarticular infections. Only genes involved in evasion of host immune defenses were more frequently carried by isolates from osteoarticular infections than from skin colonization (p = .02). Virulence gene mutations were only noted in 14 genes (three regulating biofilm formation) when comparing isolates from subjects with osteoarticular infections and those with skin colonization. Biofilm results demonstrated large heterogeneity in the isolates’ capacity to form static biofilms, with healthy control isolates producing more robust biofilm formation. Conclusions S. aureus causing osteoarticular infections are genetically heterogeneous, and more frequently harbor genes involved in immune evasion than less invasive isolates. However, virulence gene carriage overall is similar with infrequent mutations, suggesting that pathogenesis of S. aureus osteoarticular infections may be primarily regulated at transcriptional and/or translational levels.
Collapse
Affiliation(s)
- Walter Dehority
- Department of Pediatrics, The University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
- * E-mail:
| | - Valerie J. Morley
- Department of Internal Medicine, The University of New Mexico School of Medicine, Center for Global Health, Albuquerque, New Mexico, United States of America
| | - Daryl B. Domman
- Department of Internal Medicine, The University of New Mexico School of Medicine, Center for Global Health, Albuquerque, New Mexico, United States of America
| | - Seth M. Daly
- Department of Pharmaceutical Sciences, The University of New Mexico College of Pharmacy, Albuquerque, New Mexico, United States of America
| | - Kathleen D. Triplett
- Department of Pharmaceutical Sciences, The University of New Mexico College of Pharmacy, Albuquerque, New Mexico, United States of America
| | - Kylie Disch
- Department of Pediatrics, The University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | | | - Aimee Yousey
- Department of Emergency Medicine, The University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Parisa Mortaji
- Department of Internal Medicine, The University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Deirdre Hill
- The University of New Mexico Clinical and Translational Science Center, Albuquerque, New Mexico, United States of America
| | - Olufunmilola Oyebamiji
- Division of Molecular Medicine, The University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Yan Guo
- Division of Molecular Medicine, The University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Kurt Schwalm
- Department of Pediatrics, The University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Pamela R. Hall
- Department of Pharmaceutical Sciences, The University of New Mexico College of Pharmacy, Albuquerque, New Mexico, United States of America
| | - Darrell Dinwiddie
- Department of Pediatrics, The University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Jon Femling
- Department of Emergency Medicine, The University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| |
Collapse
|
3
|
Regulation of Staphylococcal Capsule by SarZ is SigA-Dependent. J Bacteriol 2022; 204:e0015222. [PMID: 35862799 PMCID: PMC9380528 DOI: 10.1128/jb.00152-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Production of capsular polysaccharides in Staphylococcus aureus is transcriptionally regulated by a control region of the cap operon that consists of SigA- and SigB-dependent promoters. A large number of regulators have been shown to affect cap gene expression. However, regulation of capsule is only partially understood. Here we found that SarZ was another regulator that activated the cap genes through the SigA-dependent promoter. Gel electrophoresis mobility shift experiments revealed that SarZ is bound to a broad region of the cap promoter including the SigA-dependent promoter but mainly the downstream region. We demonstrated that activation of cap expression by SarZ was independent of MgrA, which also activated capsule through the SigA-dependent promoter. Our results further showed that oxidative stress with hydrogen peroxide (H2O2) treatments enhanced SarZ activation of cap expression, indicating that SarZ is able to sense oxidative stress to regulate capsule production. IMPORTANCE Expression of virulence genes in Staphylococcus aureus is affected by environmental cues and is regulated by a surprisingly large number of regulators. Much is still unknown about how virulence factors are regulated by environment cues at the molecular level. Capsule is an antiphagocytic virulence factor that is highly regulated. In this study, we found SarZ was an activator of capsule and that the regulation of capsule by SarZ was affected by oxidative stress. These results provide an example of how a virulence factor could be regulated in response to an environmental cue. As the host oxidative defense system plays an important role against S. aureus, this study contributes to a better understanding of virulence gene regulation and staphylococcal pathogenesis.
Collapse
|
4
|
Antibiotic Resistance and Pathogenomics of Staphylococci Circulating in Novosibirsk, Russia. Microorganisms 2021; 9:microorganisms9122487. [PMID: 34946089 PMCID: PMC8706439 DOI: 10.3390/microorganisms9122487] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 11/26/2021] [Accepted: 11/29/2021] [Indexed: 11/16/2022] Open
Abstract
A total of 394 strains of staphylococci found in humans and pets in Novosibirsk, Siberian Russia, were characterized in terms of antibiotic resistance and corresponding genes. Two coagulase-positive and 17 coagulase-negative species were identified. The majority of isolates, with the exception of S. haemolyticus and hospital S. epidermidis isolates, were sensitive to most of the tested antibiotics, and isolates from pets displayed the lowest level of resistance. Nevertheless, methicillin-resistant (MRS) and/or multidrug-resistant (MDR) isolates were found in all prevailed species, including coagulase-negative. A set of genes corresponding to the detected resistance was identified: mecA (beta-lactam resistance), aac(6')-Ie-aph(2″)-Ia, aph(3')-IIIa, ant(4')-Ia (aminoglycoside-modifying enzymes), ermA/ermC, and msrA (macrolide resistance). Complete genome analysis for ten MDR S. epidermidis and five MDR S. haemolyticus isolates revealed additional antibiotic resistance genes mphC, qacA/qacB, norA, dfrC/dfrG, lnuA, BseSR, and fosB. NorA, dfrC, and fosB were present in all S. epidermidis genomes, whereas mphC and msrA were identified in all S. haemolyticus ones. All investigated MDR S. epidermidis and four of five S. haemolyticus strains were moderate or strong biofilm producers, whereas multiple genes responsible for this function and for virulence and pathogenicity were identified mostly in S. epidermidis, but were less frequently represented in S. haemolyticus.
Collapse
|
5
|
Altwiley D, Brignoli T, Edwards A, Recker M, Lee JC, Massey RC. A functional menadione biosynthesis pathway is required for capsule production by Staphylococcus aureus. MICROBIOLOGY (READING, ENGLAND) 2021; 167. [PMID: 34825882 PMCID: PMC8743628 DOI: 10.1099/mic.0.001108] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Staphylococcus aureus is a major human pathogen that utilises a wide array of pathogenic and immune evasion strategies to cause disease. One immune evasion strategy, common to many bacterial pathogens, is the ability of S. aureus to produce a capsule that protects the bacteria from several aspects of the human immune system. To identify novel regulators of capsule production by S. aureus, we applied a genome wide association study (GWAS) to a collection of 300 bacteraemia isolates that represent the two major MRSA clones in UK and Irish hospitals: CC22 and CC30. One of the loci associated with capsule production, the menD gene, encodes an enzyme critical to the biosynthesis of menadione. Mutations in this gene that result in menadione auxotrophy induce the slow growing small-colony variant (SCV) form of S. aureus often associated with chronic infections due to their increased resistance to antibiotics and ability to survive inside phagocytes. Utilising such an SCV, we functionally verified this association between menD and capsule production. Although the clinical isolates with polymorphisms in the menD gene in our collections had no apparent growth defects, they were more resistant to gentamicin when compared to those with the wild-type menD gene. Our work suggests that menadione is involved in the production of the S. aureus capsule, and that amongst clinical isolates polymorphisms exist in the menD gene that confer the characteristic increased gentamicin resistance, but not the major growth defect associated with SCV phenotype.
Collapse
Affiliation(s)
- Dina Altwiley
- School of Cellular and Molecular Medicine, University of Bristol, BS8 1TD, UK.,University of Jeddah, Saudi Arabia
| | - Tarcisio Brignoli
- School of Cellular and Molecular Medicine, University of Bristol, BS8 1TD, UK
| | - Andrew Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2AZ, UK
| | - Mario Recker
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, TR10 9FE, UK
| | - Jean C Lee
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Ruth C Massey
- School of Cellular and Molecular Medicine, University of Bristol, BS8 1TD, UK.,Schools of Microbiology and Medicine, and APC Microbiome Ireland, University College Cork, Ireland
| |
Collapse
|
6
|
Apt (Adenine Phosphoribosyltransferase) Mutation in Laboratory-Selected Vancomycin-Intermediate Staphylococcus aureus. Antibiotics (Basel) 2021; 10:antibiotics10050583. [PMID: 34069103 PMCID: PMC8170892 DOI: 10.3390/antibiotics10050583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/19/2021] [Accepted: 04/27/2021] [Indexed: 11/16/2022] Open
Abstract
Comparative genomic sequencing of laboratory-derived vancomycin-intermediate Staphylococcusaureus (VISA) (MM66-3 and MM66-4) revealed unique mutations in both MM66-3 (in apt and ssaA6), and MM66-4 (in apt and walK), compared to hetero-VISA parent strain MM66. Transcriptional profiling revealed that both MM66 VISA shared 79 upregulated genes and eight downregulated genes. Of these, 30.4% of the upregulated genes were associated with the cell envelope, whereas 75% of the downregulated genes were associated with virulence. In concordance with mutations and transcriptome alterations, both VISA strains demonstrated reduced autolysis, reduced growth in the presence of salt and reduced virulence factor activity. In addition to mutations in genes linked to cell wall metabolism (ssaA6 and walK), the same mutation in apt which encodes adenine phosphoribosyltransferase, was confirmed in both MM66 VISA. Apt plays a role in both adenine metabolism and accumulation and both MM66 VISA grew better than MM66 in the presence of adenine or 2-fluoroadenine indicating a reduction in the accumulation of these growth inhibiting compounds in the VISA strains. MM66 apt mutants isolated via 2-fluoroadenine selection also demonstrated reduced susceptibility to the cell wall lytic dye Congo red and vancomycin. Finding that apt mutations contribute to reduced vancomycin susceptibility once again suggests a role for altered purine metabolism in a VISA mechanism.
Collapse
|
7
|
MgrA Activates Staphylococcal Capsule via SigA-Dependent Promoter. J Bacteriol 2020; 203:JB.00495-20. [PMID: 33077637 DOI: 10.1128/jb.00495-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 10/14/2020] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus capsule polysaccharide is an important antiphagocytic virulence factor. The cap genes are regulated at the promoter element (Pcap) upstream of the cap operon. Pcap, which consists of a dominant SigB-dependent promoter and a weaker upstream SigA-dependent promoter, is activated by global regulator MgrA. How MgrA activates capsule is unclear. Here, we showed that MgrA directly bound to the Pcap region and affected the SigA-dependent promoter. Interestingly, an electrophoretic mobility shift assay showed that MgrA bound to a large region of Pcap, mainly downstream of the SigA-dependent promoter. We further showed that the ArlRS two-component system and the Agr quorum sensing system activated capsule primarily through MgrA in the early growth phases.IMPORTANCE The virulence of Staphylococcus aureus depends on the expression of various virulence factors, which is governed by a complex regulatory network. We have been using capsule as a model virulence factor to study virulence gene regulation in S. aureus MgrA is one of the regulators of capsule and has a major effect on capsule production. However, how MgrA regulates capsule genes is not understood. In this study, we were able to define the mechanism involving MgrA regulation of capsule. In addition, we also delineated the role of MgrA in capsule regulatory pathways involving the key virulence regulators Agr and Arl. This study further advances our understanding of virulence gene regulation in S. aureus, an important human pathogen.
Collapse
|
8
|
Acapsular Staphylococcus aureus with a non-functional agr regains capsule expression after passage through the bloodstream in a bacteremia mouse model. Sci Rep 2020; 10:14108. [PMID: 32839485 PMCID: PMC7445255 DOI: 10.1038/s41598-020-70671-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 07/23/2020] [Indexed: 01/18/2023] Open
Abstract
Selection pressures exerted on Staphylococcus aureus by host factors during infection may lead to the emergence of regulatory phenotypes better adapted to the infection site. Traits convenient for persistence may be fixed by mutation thus turning these mutants into microevolution endpoints. The feasibility that stable, non-encapsulated S. aureus mutants can regain expression of key virulence factors for survival in the bloodstream was investigated. S. aureus agr mutant HU-14 (IS256 insertion in agrC) from a patient with chronic osteomyelitis was passed through the bloodstream using a bacteriemia mouse model and derivative P3.1 was obtained. Although IS256 remained inserted in agrC, P3.1 regained production of capsular polysaccharide type 5 (CP5) and staphyloxanthin. Furthermore, P3.1 expressed higher levels of asp23/SigB when compared with parental strain HU-14. Strain P3.1 displayed decreased osteoclastogenesis capacity, thus indicating decreased adaptability to bone compared with strain HU-14 and exhibited a trend to be more virulent than parental strain HU-14. Strain P3.1 exhibited the loss of one IS256 copy, which was originally located in the HU-14 noncoding region between dnaG (DNA primase) and rpoD (sigA). This loss may be associated with the observed phenotype change but the mechanism remains unknown. In conclusion, S. aureus organisms that escape the infected bone may recover the expression of key virulence factors through a rapid microevolution pathway involving SigB regulation of key virulence factors.
Collapse
|
9
|
Feng Y, Yao M, Wang Y, Ding M, Zha J, Xiao W, Yuan Y. Advances in engineering UDP-sugar supply for recombinant biosynthesis of glycosides in microbes. Biotechnol Adv 2020; 41:107538. [PMID: 32222423 DOI: 10.1016/j.biotechadv.2020.107538] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/16/2020] [Accepted: 03/20/2020] [Indexed: 12/21/2022]
Abstract
Plant glycosides are of great interest for industries. Glycosylation of plant secondary metabolites can greatly improve their solubility, biological activity, or stability. This allows some plant glycosides to be used as food additives, cosmetic products, health products, antisepsis and anti-cancer drugs. With the continuous expansion of market demand, a variety of biological fermentation technologies has emerged. This review focuses on recombinant microbial biosynthesis of plant glycosides, which uses UDP-sugars as precursors, and summarizes various strategies to increase the yield of glycosides with a key concentration on UDP-sugar supply based on four aspects, i.e., gene overexpression, UDP-sugar recycling, mixed fermentation, and carbon co-utilization. Meanwhile, the application potential and advantages of various techniques are introduced, which provide guidance to the development of high-yield strains for recombinant microbial production of plant glycosides. Finally, the technical challenges of glycoside biosynthesis are pointed out with discussions on future directions of improving the yield of recombinantly synthesized glycosides.
Collapse
Affiliation(s)
- Yueyang Feng
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Mingdong Yao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Ying Wang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Mingzhu Ding
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Jian Zha
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
| | - Wenhai Xiao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China.
| | - Yingjin Yuan
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| |
Collapse
|
10
|
MgrA Negatively Impacts Staphylococcus aureus Invasion by Regulating Capsule and FnbA. Infect Immun 2019; 87:IAI.00590-19. [PMID: 31591167 DOI: 10.1128/iai.00590-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 09/27/2019] [Indexed: 01/19/2023] Open
Abstract
Virulence genes are regulated by a complex regulatory network in Staphylococcus aureus Some of the regulators are global in nature and affect many downstream genes. MgrA is a multiple-gene regulator that has been shown to activate genes involved in capsule biosynthesis and repress surface protein genes. The goal of this study was to demonstrate the biological significance of MgrA regulation of capsule and surface proteins. We found that strain Becker possessed one fibronectin-binding protein, FnbA, and that FnbA was the predominant protein involved in invasion of nonphagocytic HeLa cells. By genetic analysis of strains with different amounts of capsule, we demonstrated that capsule impeded invasion of HeLa cells by masking the bacterial cell wall-anchored protein FnbA. Using variants with different levels of mgrA transcription, we further demonstrated that MgrA negatively impacted invasion by activating the cap genes involved in capsule biosynthesis and repressing the fnbA gene. Thus, we conclude that MgrA negatively impacts cell invasion of S. aureus Becker by promoting capsule and repressing FnbA.
Collapse
|
11
|
Keinhörster D, George SE, Weidenmaier C, Wolz C. Function and regulation of Staphylococcus aureus wall teichoic acids and capsular polysaccharides. Int J Med Microbiol 2019; 309:151333. [DOI: 10.1016/j.ijmm.2019.151333] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 07/09/2019] [Accepted: 07/17/2019] [Indexed: 01/05/2023] Open
|