1
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Xu Z, Li Y, Xu A, Soteyome T, Yuan L, Ma Q, Seneviratne G, Li X, Liu J. Cell-wall-anchored proteins affect invasive host colonization and biofilm formation in Staphylococcus aureus. Microbiol Res 2024; 285:127782. [PMID: 38833832 DOI: 10.1016/j.micres.2024.127782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 05/21/2024] [Accepted: 05/21/2024] [Indexed: 06/06/2024]
Abstract
As a major human and animal pathogen, Staphylococcus aureus can attach to medical implants (abiotic surface) or host tissues (biotic surface), and further establish robust biofilms which enhances resistance and persistence to host immune system and antibiotics. Cell-wall-anchored proteins (CWAPs) covalently link to peptidoglycan, and largely facilitate the colonization of S. aureus on various surfaces (including adhesion and biofilm formation) and invasion into host cells (including adhesion, immune evasion, iron acquisition and biofilm formation). During biofilm formation, CWAPs function in adhesion, aggregation, collagen-like fiber network formation, and consortia formation. In this review, we firstly focus on the structural features of CWAPs, including their intracellular function and interactions with host cells, as well as the functions and ligand binding of CWAPs in different stages of S. aureus biofilm formation. Then, the roles of CWAPs in different biofilm processes with regards in development of therapeutic approaches are clarified, followed by the association between CWAPs genes and clonal lineages. By touching upon these aspects, we hope to provide comprehensive knowledge and clearer understanding on the CWAPs of S. aureus and their roles in biofilm formation, which may further aid in prevention and treatment infection and vaccine development.
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Affiliation(s)
- Zhenbo Xu
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Engineering Research Center of Starch and Vegetable Protein Processing Ministry of Education, South China University of Technology, Guangzhou 510640, China; Department of Laboratory Medicine, the Second Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, China.
| | - Yaqin Li
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Engineering Research Center of Starch and Vegetable Protein Processing Ministry of Education, South China University of Technology, Guangzhou 510640, China
| | - Aijuan Xu
- Guangzhou Hybribio Medical Laboratory, Guangzhou 510730, China
| | - Thanapop Soteyome
- Home Economics Technology, Rajamangala University of Technology Phra Nakhon, Bangkok, Thailand
| | - Lei Yuan
- School of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China
| | - Qin Ma
- Sericultural & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture /Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China
| | - Gamini Seneviratne
- National Institute of Fundamental Studies, Hantana road, Kandy, Sri Lanka
| | - Xuejie Li
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Engineering Research Center of Starch and Vegetable Protein Processing Ministry of Education, South China University of Technology, Guangzhou 510640, China.
| | - Junyan Liu
- College of Light Industry and Food Science, Guangdong Provincial Key Laboratory of Lingnan Specialty Food Science and Technology, Academy of Contemporary Agricultural Engineering Innovations, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China; Key Laboratory of Green Processing and Intelligent Manufacturing of Lingnan Specialty Food, Ministry of Agriculture, Guangzhou 510225, China.
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2
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Mei M, Lu M, Li S, Ren X, Xing B, Hu Y, Wu Y, Chen H, Wang L, Yi L, Ming K, Wei Z. Development of nanobodies specific to clumping factors A of Staphylococcus aureus by yeast surface display. Int J Biol Macromol 2024; 259:129208. [PMID: 38185298 DOI: 10.1016/j.ijbiomac.2024.129208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/25/2023] [Accepted: 01/01/2024] [Indexed: 01/09/2024]
Abstract
The Staphylococcus aureus clumping factor A (ClfA) is a fibrinogen (Fg) binding protein that plays an important role in the clumping of S. aureus in blood plasma. The current anti-infective approaches targeting ClfA are mainly based on monoclonal antibodies but showed less impressive efficacy for clinical applications. Nanobodies offer advantages in enhanced tissue penetration and a propensity to bind small epitopes. However, there is no report on generating specific nanobodies for ClfA. Here, we constructed a synthetic nanobody library based on yeast surface display to isolate nanobodies against the Fg binding domain ClfA221-550. We firstly obtained a primary nanobody directed to ClfA221-550, and then employed error-prone mutagenesis to enhance its binding affinity. Finally, 18 variants were isolated with high affinities (EC50, 1.1 ± 0.1 nM to 4.8 ± 0.3 nM), in which CNb1 presented the highest inhibition efficiency in the adhesion of S. aureus to fibrinogen. Moreover, structural simulation analysis indicated that the epitope for CNb1 partially overlapped with the binding sites for fibrinogen, thus inhibiting ClfA binding to Fg. Overall, these results indicated that the specific nanobodies generated here could prevent the adhesion of S. aureus to fibrinogen, suggesting their potential capacities in the control of S. aureus infections.
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Affiliation(s)
- Meng Mei
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China; Hubei Jiangxia Laboratory, Wuhan, Hubei, China
| | - Mengqing Lu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Shiqi Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Xinyi Ren
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Banbin Xing
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Yang Hu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Yuqi Wu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Huan Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Longhao Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Li Yi
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Ke Ming
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China; Hubei Jiangxia Laboratory, Wuhan, Hubei, China
| | - Zigong Wei
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China; Hubei Jiangxia Laboratory, Wuhan, Hubei, China; Hubei Province Key Laboratory of Biotechnology of Chinese Traditional Medicine, National & Local Joint Engineering Research Center of High-throughput Drug Screening Technology, School of life sciences, Hubei University, Wuhan, Hubei, PR China.
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3
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Francis D, Veeramanickathadathil Hari G, Koonthanmala Subash A, Bhairaddy A, Joy A. The biofilm proteome of Staphylococcus aureus and its implications for therapeutic interventions to biofilm-associated infections. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 138:327-400. [PMID: 38220430 DOI: 10.1016/bs.apcsb.2023.08.002] [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: 01/16/2024]
Abstract
Staphylococcus aureus is a major healthcare concern due to its ability to inflict life-threatening infections and evolve antibiotic resistance at an alarming pace. It is frequently associated with hospital-acquired infections, especially device-associated infections. Systemic infections due to S. aureus are difficult to treat and are associated with significant mortality and morbidity. The situation is worsened by the ability of S. aureus to form social associations called biofilms. Biofilms embed a community of cells with the ability to communicate with each other and share resources within a polysaccharide or protein matrix. S. aureus establish biofilms on tissues and conditioned abiotic surfaces. Biofilms are hyper-tolerant to antibiotics and help evade host immune responses. Biofilms exacerbate the severity and recalcitrance of device-associated infections. The development of a biofilm involves various biomolecules, such as polysaccharides, proteins and nucleic acids, contributing to different structural and functional roles. Interconnected signaling pathways and regulatory molecules modulate the expression of these molecules. A comprehensive understanding of the molecular biology of biofilm development would help to devise effective anti-biofilm therapeutics. Although bactericidal agents, antimicrobial peptides, bacteriophages and nano-conjugated anti-biofilm agents have been employed with varying levels of success, there is still a requirement for effective and clinically viable anti-biofilm therapeutics. Proteins that are expressed and utilized during biofilm formation, constituting the biofilm proteome, are a particularly attractive target for anti-biofilm strategies. The proteome can be explored to identify potential anti-biofilm drug targets and utilized for rational drug discovery. With the aim of uncovering the biofilm proteome, this chapter explores the mechanism of biofilm formation and its regulation. Furthermore, it explores the antibiofilm therapeutics targeted against the biofilm proteome.
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Affiliation(s)
- Dileep Francis
- Department of Life Sciences, Kristu Jayanti College (Autonomous), Bengaluru, India.
| | | | | | - Anusha Bhairaddy
- Department of Life Sciences, Kristu Jayanti College (Autonomous), Bengaluru, India
| | - Atheene Joy
- Department of Life Sciences, Kristu Jayanti College (Autonomous), Bengaluru, India
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4
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Yan X, Xu Y, Shen C, Chen D. Inactivation of Staphylococcus aureus by Levulinic Acid Plus Sodium Dodecyl Sulfate and their Antibacterial Mechanisms on S. aureus Biofilms by Transcriptomic Analysis. J Food Prot 2023; 86:100050. [PMID: 36916557 DOI: 10.1016/j.jfp.2023.100050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 01/14/2023] [Accepted: 01/18/2023] [Indexed: 01/27/2023]
Abstract
The combination of levulinic acid (LVA) and sodium dodecyl sulfate (SDS) in recent years has shown a considerable potential to use as an antimicrobial intervention. The objectives of this study were to evaluate the antimicrobial efficacy of the combination against Staphylococcus aureus in both planktonic and biofilm states and to investigate the transcriptional changes in S. aureus biofilms coincubated with sublethal concentrations of LVA and/or SDS. The minimum inhibitory concentrations (MICs) of LVA and SDS determined by the microdilution method were 3.125 and 0.039 mg/mL, respectively. An additive bacteriostatic interaction (fractional inhibitory concentration index = 1) between the two compounds was observed by the checkerboard assay, whereas a synergistic bactericidal activity was displayed by the time-kill assay. The biomass and viable cells in the biofilms were reduced by both antimicrobials either alone or in combination in a dose-dependent manner. Transcriptomics indicated that more differentially expressed (DE) genes were observed in the biofilm treated with SDS (103 up- and 205 downregulated DE genes) and LVA + SDS (187 up and 162 down) than that coincubated with LVA (34 up and 32 down). The SDS and LVA + SDS treatments mainly affected the expression of genes responsible for cell surface proteins, virulence factors, adhesins, and capsular polysaccharides. Both the antibiofilm assay and the transcriptomics indicated that SDS, not LVA, was the major chemical contributing to the antibacterial efficacy of the combination. This study reveals the behavioral responses and protective mechanisms of S. aureus to LVA and SDS applied individually or in combination.
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Affiliation(s)
- Xiaoxue Yan
- College of Food Science, Southwest University, 2 Tiansheng Rd, Beibei, Chongqing 400715, China; Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, 400715, China
| | - Yiwei Xu
- College of Food Science, Southwest University, 2 Tiansheng Rd, Beibei, Chongqing 400715, China; Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, 400715, China
| | - Cangliang Shen
- Division of Animal and Nutritional Sciences, West Virginia University, Morgantown, WV 26506, USA
| | - Dong Chen
- College of Food Science, Southwest University, 2 Tiansheng Rd, Beibei, Chongqing 400715, China; Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, 400715, China.
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5
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Risser F, López-Morales J, Nash MA. Adhesive Virulence Factors of Staphylococcus aureus Resist Digestion by Coagulation Proteases Thrombin and Plasmin. ACS BIO & MED CHEM AU 2022; 2:586-599. [PMID: 36573096 PMCID: PMC9782320 DOI: 10.1021/acsbiomedchemau.2c00042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/22/2022] [Accepted: 08/22/2022] [Indexed: 12/30/2022]
Abstract
Staphylococcus aureus (S. aureus) is an invasive and life-threatening pathogen that has undergone extensive coevolution with its mammalian hosts. Its molecular adaptations include elaborate mechanisms for immune escape and hijacking of the coagulation and fibrinolytic pathways. These capabilities are enacted by virulence factors including microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) and the plasminogen-activating enzyme staphylokinase (SAK). Despite the ability of S. aureus to modulate coagulation, until now the sensitivity of S. aureus virulence factors to digestion by proteases of the coagulation system was unknown. Here, we used protein engineering, biophysical assays, and mass spectrometry to study the susceptibility of S. aureus MSCRAMMs to proteolytic digestion by human thrombin, plasmin, and plasmin/SAK complexes. We found that MSCRAMMs were highly resistant to proteolysis, and that SAK binding to plasmin enhanced this resistance. We mapped thrombin, plasmin, and plasmin/SAK cleavage sites of nine MSCRAMMs and performed biophysical, bioinformatic, and stability analysis to understand structural and sequence features common to protease-susceptible sites. Overall, our study offers comprehensive digestion patterns of S. aureus MSCRAMMs by thrombin, plasmin, and plasmin/SAK complexes and paves the way for new studies into this resistance and virulence mechanism.
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Affiliation(s)
- Fanny Risser
- Institute
of Physical Chemistry, Department of Chemistry, University of Basel, 4058 Basel, Switzerland,Department
of Biosystems Sciences and Engineering, ETH Zurich, 4058 Basel, Switzerland
| | - Joanan López-Morales
- Institute
of Physical Chemistry, Department of Chemistry, University of Basel, 4058 Basel, Switzerland,Department
of Biosystems Sciences and Engineering, ETH Zurich, 4058 Basel, Switzerland
| | - Michael A. Nash
- Institute
of Physical Chemistry, Department of Chemistry, University of Basel, 4058 Basel, Switzerland,Department
of Biosystems Sciences and Engineering, ETH Zurich, 4058 Basel, Switzerland,E-mail:
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6
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Sun Z, Zhang X, Zhou D, Zhou K, Li Q, Lin H, Lu W, Liu H, Lu J, Lin X, Li K, Xu T, Zhu M, Bao Q, Zhang H. Identification of Three Clf-Sdr Subfamily Proteins in Staphylococcus warneri, and Comparative Genomics Analysis of a Locus Encoding CWA Proteins in Staphylococcus Species. Front Microbiol 2021; 12:691087. [PMID: 34394031 PMCID: PMC8360574 DOI: 10.3389/fmicb.2021.691087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 06/28/2021] [Indexed: 11/13/2022] Open
Abstract
Coagulase-negative Staphylococcus warneri is an opportunistic pathogen that is capable of causing several infections, especially in patients with indwelling medical devices. Here, we determined the complete genome sequence of a clinical S. warneri strain isolated from the blood culture of a 1-year-old nursling patient with acute upper respiratory infection. Genome-wide phylogenetic analysis confirmed the phylogenetic relationships between S. warneri and other Staphylococcus species. Using comparative genomics, we identified three cell wall-anchored (CWA) proteins at the same locus (sdr), named SdrJ, SdrK, and SdrL, on the chromosome sequences of different S. warneri strains. Structural predictions showed that SdrJ/K/L have structural features characteristic of Sdr proteins but exceptionally contained an unusual N-terminal repeat region. However, the C-terminal repetitive (R) region of SdrJ contains a significantly larger proportion of alanine (142/338, 42.01%) than the previously reported SdrI (37.00%). Investigation of the genetic organization revealed that the sdrJ/K/L genes were always followed by one or two glycosyltransferase genes, gtfA and gtfB and were present in an ∼56 kb region bordered by a pair of 8 bp identical direct repeats, named Sw-Sdr. This region was further found to be located on a 160-kb region subtended by a pair of 160-bp direct repeats along with other virulence genes and resistance genes. Sw-Sdr contained a putative integrase that was probably a remnant of a functional integrase. Evidence suggests that Sw-Sdr is improbably an efficient pathogenicity island. A large-scale investigation of Staphylococcus genomes showed that sdr loci were a potential hotspot of insertion sequences (ISs), which could lead to intraspecific diversity at these loci. Our work expanded the repository of Staphylococcus Sdr proteins, and for the first time, we established the connection between sdr loci and phylogenetic relationships and compared the sdr loci in different Staphylococcus species, which provided large insights into the genetic environment of CWA genes in Staphylococcus.
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Affiliation(s)
- Zhewei Sun
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Xueya Zhang
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Danying Zhou
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Kexin Zhou
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Qiaoling Li
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Hailong Lin
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Wei Lu
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Hongmao Liu
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Junwan Lu
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Xi Lin
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Kewei Li
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Teng Xu
- Institute of Translational Medicine, Baotou Central Hospital, Baotou, China
| | - Mei Zhu
- Department of Clinical Laboratory, Zhejiang Hospital, Hangzhou, China
| | - Qiyu Bao
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Hailin Zhang
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
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7
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Su M, Davis MH, Peterson J, Solis-Lemus C, Satola SW, Read TD. Effect of genetic background on the evolution of Vancomycin-Intermediate Staphylococcus aureus (VISA). PeerJ 2021; 9:e11764. [PMID: 34306830 PMCID: PMC8284308 DOI: 10.7717/peerj.11764] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 06/22/2021] [Indexed: 11/20/2022] Open
Abstract
Vancomycin-intermediate Staphylococcus aureus (VISA) typically arises through accumulation of chromosomal mutations that alter cell-wall thickness and global regulatory pathways. Genome-based prediction of VISA requires understanding whether strain background influences patterns of mutation that lead to resistance. We used an iterative method to experimentally evolve three important methicillin-resistant S. aureus (MRSA) strain backgrounds-(CC1, CC5 and CC8 (USA300)) to generate a library of 120 laboratory selected VISA isolates. At the endpoint, isolates had vancomycin MICs ranging from 4 to 10 μg/mL. We detected mutations in more than 150 genes, but only six genes (already known to be associated with VISA from prior studies) were mutated in all three background strains (walK, prs, rpoB, rpoC, vraS, yvqF). We found evidence of interactions between loci (e.g., vraS and yvqF mutants were significantly negatively correlated) and rpoB, rpoC, vraS and yvqF were more frequently mutated in one of the backgrounds. Increasing vancomycin resistance was correlated with lower maximal growth rates (a proxy for fitness) regardless of background. However, CC5 VISA isolates had higher MICs with fewer rounds of selection and had lower fitness costs than the CC8 VISA isolates. Using multivariable regression, we found that genes differed in their contribution to overall MIC depending on the background. Overall, these results demonstrated that VISA evolved through mutations in a similar set of loci in all backgrounds, but the effect of mutation in common genes differed with regard to fitness and contribution to resistance in different strains.
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Affiliation(s)
- Michelle Su
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Michelle H Davis
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Jessica Peterson
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Claudia Solis-Lemus
- Wisconsin Institute for Discovery and Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Sarah W Satola
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Timothy D Read
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Atlanta, Georgia, USA.,Department of Dermatology, School of Medicine, Emory University, Atlanta, Georgia, USA
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8
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Wang J, Zhang M, Wang M, Zang J, Zhang X, Hang T. Structural insights into the intermolecular interaction of the adhesin SdrC in the pathogenicity of Staphylococcus aureus. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2021; 77:47-53. [PMID: 33620037 DOI: 10.1107/s2053230x21000741] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/21/2021] [Indexed: 11/10/2022]
Abstract
Staphylococcus aureus is an opportunistic disease-causing pathogen that is widely found in the community and on medical equipment. A series of virulence factors secreted by S. aureus can trigger severe diseases such as sepsis, endocarditis and toxic shock, and thus have a great impact on human health. The transformation of S. aureus from a colonization state to a pathogenic state during its life cycle is intimately associated with the initiation of bacterial aggregation and biofilm accumulation. SdrC, an S. aureus surface protein, can act as an adhesin to promote cell attachment and aggregation by an unknown mechanism. Here, structural studies demonstrate that SdrC forms a unique dimer through intermolecular interaction. It is proposed that the dimerization of SdrC enhances the efficiency of bacteria-host attachment and therefore contributes to the pathogenicity of S. aureus.
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Affiliation(s)
- Junchao Wang
- School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei, Anhui 230601, People's Republic of China
| | - Min Zhang
- School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei, Anhui 230601, People's Republic of China
| | - Mingzhu Wang
- Institute of Health Sciences and Technology, Anhui University, 111 Jiulong Road, Hefei, Anhui 230601, People's Republic of China
| | - Jianye Zang
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Center for Excellence in Biomacromolecules, Collaborative Innovation Center of Chemistry for Life Sciences and School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, People's Republic of China
| | - Xuan Zhang
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Center for Excellence in Biomacromolecules, Collaborative Innovation Center of Chemistry for Life Sciences and School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, People's Republic of China
| | - Tianrong Hang
- School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei, Anhui 230601, People's Republic of China
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9
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Schilcher K, Horswill AR. Staphylococcal Biofilm Development: Structure, Regulation, and Treatment Strategies. Microbiol Mol Biol Rev 2020. [PMID: 32792334 DOI: 10.1128/mmbr.00026-19/asset/e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023] Open
Abstract
In many natural and clinical settings, bacteria are associated with some type of biotic or abiotic surface that enables them to form biofilms, a multicellular lifestyle with bacteria embedded in an extracellular matrix. Staphylococcus aureus and Staphylococcus epidermidis, the most frequent causes of biofilm-associated infections on indwelling medical devices, can switch between an existence as single free-floating cells and multicellular biofilms. During biofilm formation, cells first attach to a surface and then multiply to form microcolonies. They subsequently produce the extracellular matrix, a hallmark of biofilm formation, which consists of polysaccharides, proteins, and extracellular DNA. After biofilm maturation into three-dimensional structures, the biofilm community undergoes a disassembly process that leads to the dissemination of staphylococcal cells. As biofilms are dynamic and complex biological systems, staphylococci have evolved a vast network of regulatory mechanisms to modify and fine-tune biofilm development upon changes in environmental conditions. Thus, biofilm formation is used as a strategy for survival and persistence in the human host and can serve as a reservoir for spreading to new infection sites. Moreover, staphylococcal biofilms provide enhanced resilience toward antibiotics and the immune response and impose remarkable therapeutic challenges in clinics worldwide. This review provides an overview and an updated perspective on staphylococcal biofilms, describing the characteristic features of biofilm formation, the structural and functional properties of the biofilm matrix, and the most important mechanisms involved in the regulation of staphylococcal biofilm formation. Finally, we highlight promising strategies and technologies, including multitargeted or combinational therapies, to eradicate staphylococcal biofilms.
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Affiliation(s)
- Katrin Schilcher
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
- Department of Veterans Affairs Eastern Colorado Health Care System, Denver, Colorado, USA
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10
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Staphylococcal Biofilm Development: Structure, Regulation, and Treatment Strategies. Microbiol Mol Biol Rev 2020; 84:84/3/e00026-19. [PMID: 32792334 DOI: 10.1128/mmbr.00026-19] [Citation(s) in RCA: 279] [Impact Index Per Article: 69.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In many natural and clinical settings, bacteria are associated with some type of biotic or abiotic surface that enables them to form biofilms, a multicellular lifestyle with bacteria embedded in an extracellular matrix. Staphylococcus aureus and Staphylococcus epidermidis, the most frequent causes of biofilm-associated infections on indwelling medical devices, can switch between an existence as single free-floating cells and multicellular biofilms. During biofilm formation, cells first attach to a surface and then multiply to form microcolonies. They subsequently produce the extracellular matrix, a hallmark of biofilm formation, which consists of polysaccharides, proteins, and extracellular DNA. After biofilm maturation into three-dimensional structures, the biofilm community undergoes a disassembly process that leads to the dissemination of staphylococcal cells. As biofilms are dynamic and complex biological systems, staphylococci have evolved a vast network of regulatory mechanisms to modify and fine-tune biofilm development upon changes in environmental conditions. Thus, biofilm formation is used as a strategy for survival and persistence in the human host and can serve as a reservoir for spreading to new infection sites. Moreover, staphylococcal biofilms provide enhanced resilience toward antibiotics and the immune response and impose remarkable therapeutic challenges in clinics worldwide. This review provides an overview and an updated perspective on staphylococcal biofilms, describing the characteristic features of biofilm formation, the structural and functional properties of the biofilm matrix, and the most important mechanisms involved in the regulation of staphylococcal biofilm formation. Finally, we highlight promising strategies and technologies, including multitargeted or combinational therapies, to eradicate staphylococcal biofilms.
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11
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Belikova D, Jochim A, Power J, Holden MTG, Heilbronner S. "Gene accordions" cause genotypic and phenotypic heterogeneity in clonal populations of Staphylococcus aureus. Nat Commun 2020; 11:3526. [PMID: 32665571 PMCID: PMC7360770 DOI: 10.1038/s41467-020-17277-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 06/15/2020] [Indexed: 12/18/2022] Open
Abstract
Gene tandem amplifications are thought to drive bacterial evolution, but they are transient in the absence of selection, making their investigation challenging. Here, we analyze genomic sequences of Staphylococcus aureus USA300 isolates from the same geographical area to identify variations in gene copy number, which we confirm by long-read sequencing. We find several hotspots of variation, including the csa1 cluster encoding lipoproteins known to be immunogenic. We also show that the csa1 locus expands and contracts during bacterial growth in vitro and during systemic infection of mice, and recombination creates rapid heterogeneity in initially clonal cultures. Furthermore, csa1 copy number variants differ in their immunostimulatory capacity, revealing a mechanism by which gene copy number variation can modulate the host immune response. Gene tandem amplifications can drive bacterial evolution. Here, Belikova et al. identify copy number variations of lipoprotein-encoding genes in Staphylococcus aureus clinical isolates, and show that the loci expand and contract during bacterial growth in vitro and in mice, leading to changes in immunostimulatory capacity.
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Affiliation(s)
- Darya Belikova
- Interfaculty Institute of Microbiology and Infection Medicine, Department of Infection Biology, University of Tübingen, Tübingen, Germany
| | - Angelika Jochim
- Interfaculty Institute of Microbiology and Infection Medicine, Department of Infection Biology, University of Tübingen, Tübingen, Germany
| | - Jeffrey Power
- Interfaculty Institute of Microbiology and Infection Medicine, Department of Infection Biology, University of Tübingen, Tübingen, Germany
| | | | - Simon Heilbronner
- Interfaculty Institute of Microbiology and Infection Medicine, Department of Infection Biology, University of Tübingen, Tübingen, Germany. .,German Centre for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany. .,(DFG) Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, Tübingen, Germany.
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12
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Carothers KE, Liang Z, Mayfield J, Donahue DL, Lee M, Boggess B, Ploplis VA, Castellino FJ, Lee SW. The Streptococcal Protease SpeB Antagonizes the Biofilms of the Human Pathogen Staphylococcus aureus USA300 through Cleavage of the Staphylococcal SdrC Protein. J Bacteriol 2020; 202:e00008-20. [PMID: 32205460 PMCID: PMC7221255 DOI: 10.1128/jb.00008-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Accepted: 03/06/2020] [Indexed: 01/11/2023] Open
Abstract
Streptococcus pyogenes, or group A Streptococcus (GAS), is both a pathogen and an asymptomatic colonizer of human hosts and produces a large number of surface-expressed and secreted factors that contribute to a variety of infection outcomes. The GAS-secreted cysteine protease SpeB has been well studied for its effects on the human host; however, despite its broad proteolytic activity, studies on how this factor is utilized in polymicrobial environments are lacking. Here, we utilized various forms of SpeB protease to evaluate its antimicrobial and antibiofilm properties against the clinically important human colonizer Staphylococcus aureus, which occupies niches similar to those of GAS. For our investigation, we used a skin-tropic GAS strain, AP53CovS+, and its isogenic ΔspeB mutant to compare the production and activity of native SpeB protease. We also generated active and inactive forms of recombinant purified SpeB for functional studies. We demonstrate that SpeB exhibits potent biofilm disruption activity at multiple stages of S. aureus biofilm formation. We hypothesized that the surface-expressed adhesin SdrC in S. aureus was cleaved by SpeB, which contributed to the observed biofilm disruption. Indeed, we found that SpeB cleaved recombinant SdrC in vitro and in the context of the full S. aureus biofilm. Our results suggest an understudied role for the broadly proteolytic SpeB as an important factor for GAS colonization and competition with other microorganisms in its niche.IMPORTANCEStreptococcus pyogenes (GAS) causes a range of diseases in humans, ranging from mild to severe, and produces many virulence factors in order to be a successful pathogen. One factor produced by many GAS strains is the protease SpeB, which has been studied for its ability to cleave and degrade human proteins, an important factor in GAS pathogenesis. An understudied aspect of SpeB is the manner in which its broad proteolytic activity affects other microorganisms that co-occupy niches similar to that of GAS. The significance of the research reported herein is the demonstration that SpeB can degrade the biofilms of the human pathogen Staphylococcus aureus, which has important implications for how SpeB may be utilized by GAS to successfully compete in a polymicrobial environment.
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Affiliation(s)
- Katelyn E Carothers
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, USA
| | - Zhong Liang
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana, USA
| | - Jeffrey Mayfield
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana, USA
| | - Deborah L Donahue
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana, USA
| | - Mijoon Lee
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Bill Boggess
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Victoria A Ploplis
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana, USA
| | - Francis J Castellino
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana, USA
| | - Shaun W Lee
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, USA
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana, USA
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13
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Abstract
Staphylococcus aureus surface proteins play important roles in host tissue colonization, biofilm formation, and bacterial virulence and are thus essential for successful host infections. The surface protein SdrC from S. aureus induces bacterial biofilm formation via an intermolecular homophilic interaction of its N2 domains. However, the molecular mechanism of how the homophilic interaction is achieved is unknown. Here, we report two crystal structures of SdrC N2N3 domains, revealing two possible homophilic interaction mechanisms: Ca2+-mediated intermolecular metal chelation of N2 domains and intermolecular interaction of N2 and N3 domains. Given the unnecessary role of the N3 domain in the induction of biofilm formation, the N2 domain-mediated metal chelation mechanism is likely the mechanism that facilitates SdrC homophilic interaction. Mutation of key Ca2+-chelating residues differentially reduced the level of protein dimer formation, further supporting the key role of metal chelation in the N2 domain interaction. Together, these results reveal the possible mechanism of the homophilic interaction of SdrC N2 domains and pave the way for the rational development of new strategies against this mechanism.
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Affiliation(s)
- Yishuang Pi
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.,Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200032, China
| | - Weizhong Chen
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Quanjiang Ji
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.,Key Laboratory for Molecular Engineering of Chiral Drugs, Shanghai Jiao Tong University, Shanghai 200240, China
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14
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Abstract
The surface of Staphylococcus aureus is decorated with over 20 proteins that are covalently anchored to peptidoglycan by the action of sortase A. These cell wall-anchored (CWA) proteins can be classified into several structural and functional groups. The largest is the MSCRAMM family, which is characterized by tandemly repeated IgG-like folded domains that bind peptide ligands by the dock lock latch mechanism or the collagen triple helix by the collagen hug. Several CWA proteins comprise modules that have different functions, and some individual domains can bind different ligands, sometimes by different mechanisms. For example, the N-terminus of the fibronectin binding proteins comprises an MSCRAMM domain which binds several ligands, while the C-terminus is composed of tandem fibronectin binding repeats. Surface proteins promote adhesion to host cells and tissue, including components of the extracellular matrix, contribute to biofilm formation by stimulating attachment to the host or indwelling medical devices followed by cell-cell accumulation via homophilic interactions between proteins on neighboring cells, help bacteria evade host innate immune responses, participate in iron acquisition from host hemoglobin, and trigger invasion of bacteria into cells that are not normally phagocytic. The study of genetically manipulated strains using animal infection models has shown that many CWA proteins contribute to pathogenesis. Fragments of CWA proteins have the potential to be used in multicomponent vaccines to prevent S. aureus infections.
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15
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The MSCRAMM Family of Cell-Wall-Anchored Surface Proteins of Gram-Positive Cocci. Trends Microbiol 2019; 27:927-941. [PMID: 31375310 DOI: 10.1016/j.tim.2019.06.007] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/10/2019] [Accepted: 06/19/2019] [Indexed: 01/21/2023]
Abstract
The microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) are a family of proteins that are defined by the presence of two adjacent IgG-like folded subdomains. These promote binding to ligands by mechanisms that involve major conformational changes exemplified by the binding to fibrinogen by the 'dock-lock-latch' mechanism or to collagen by the 'collagen hug'. Clumping factors A and B are two such MSCRAMMs that have several important roles in the pathogenesis of Staphylococcus aureus infections. MSCRAMM architecture, ligand binding, and roles in infection and colonization are examined with a focus on recent developments with clumping factors.
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16
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Adaligil E, Patil K, Rodenstein M, Kumar K. Discovery of Peptide Antibiotics Composed of d-Amino Acids. ACS Chem Biol 2019; 14:1498-1506. [PMID: 31243959 DOI: 10.1021/acschembio.9b00234] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A paucity of viable programs and pipelines for the discovery of new antibiotics poses a significant public health threat. The emergence of resistant strains against vancomycin is particularly dangerous in hospital settings. Here, we report the design of enantiomeric targets based on bacterial cell wall biosynthesis precursors that allow for selection and identification of short linear, cyclic and bicyclic peptides that are composed of d-amino acids. These compounds are active against Staphylococcus aureus, Methicillin-resistant S. aureus, and vancomycin-resistant Enterococci that possess moderately high antibacterial activity and furthermore display no toxicity to both human red blood cells and mammalian cells at these concentrations. This 'mirror image phage display' approach yielded templates that can serve as scaffolds for further improvements in activity-based structural modifications. This strategy has the potential to provide a new class of antimicrobials that are metabolically stable and have the promise for oral delivery. The use of this platform combined with traditional medicinal chemistry approaches could rapidly yield large numbers of new therapeutic lead compounds.
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Affiliation(s)
- Emel Adaligil
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Kalyani Patil
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Marissa Rodenstein
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Krishna Kumar
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States
- Cancer Center, Tufts Medical Center, Boston, Massachusetts 02110, United States
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17
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Sortases, Surface Proteins, and Their Roles in Staphylococcus aureus Disease and Vaccine Development. Microbiol Spectr 2019; 7. [PMID: 30737913 DOI: 10.1128/microbiolspec.psib-0004-2018] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Sortases cleave short peptide motif sequences at the C-terminal end of secreted surface protein precursors and either attach these polypeptides to the peptidoglycan of Gram-positive bacteria or promote their assembly into pilus structures that are also attached to peptidoglycan. Sortase A, the enzyme first identified in the human pathogen Staphylococcus aureus, binds LPXTG motif sorting signals, cleaves between threonine (T) and glycine (G) residues, and forms an acyl enzyme between its active-site cysteine thiol and the carboxyl group of threonine (T). Sortase A acyl enzyme is relieved by the nucleophilic attack of the cross bridge amino group within lipid II, thereby generating surface protein linked to peptidoglycan precursor. Such products are subsequently incorporated into the cell wall envelope by enzymes of the peptidoglycan synthesis pathway. Surface proteins linked to peptidoglycan may be released from the bacterial envelope to diffuse into host tissues and fulfill specific biological functions. S. aureus sortase A is essential for host colonization and for the pathogenesis of invasive diseases. Staphylococcal sortase-anchored surface proteins fulfill key functions during the infectious process, and vaccine-induced antibodies targeting surface proteins may provide protection against S. aureus. Alternatively, small-molecule inhibitors of sortase may be useful agents for the prevention of S. aureus colonization and invasive disease.
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18
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Ajayi C, Åberg E, Askarian F, Sollid JUE, Johannessen M, Hanssen AM. Genetic variability in the sdrD gene in Staphylococcus aureus from healthy nasal carriers. BMC Microbiol 2018; 18:34. [PMID: 29661152 PMCID: PMC5902956 DOI: 10.1186/s12866-018-1179-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 04/08/2018] [Indexed: 11/26/2022] Open
Abstract
Background Staphylococcus aureus cell wall anchored Serine Aspartate repeat containing protein D (SdrD) is a member of the microbial surface component recognising adhesive matrix molecules (MSCRAMMs). It is involved in the bacterial adhesion and virulence. However the extent of genetic variation in S. aureus sdrD gene within isolates from healthy carriers are not known. The aim of this study was to evaluate allelic variation of the sdrD gene among S. aureus from healthy nasal carriers. Results The sdrD A region from 48 S. aureus isolates from healthy carriers were analysed and classified into seven variants. Variations in the sdrD A region were concentrated in the N2 and N3 subdomains. Sequence analysis of the entire sdrD gene of representative isolates revealed variations in the SD repeat and the EF motifs of the B repeat. In silico structural modelling indicates that there are no differences in the SdrD structure of the 7 variants. Variable amino acid residues mapped onto the 3D structure revealed that the variations are surface located, exist within the groove between the N2-N3 subdomains and distributed mainly on the N3 subdomain. Comparison of adhesion to keratinocytes in an in vitro cell adhesion assay, using NCTC 8325–4∆sdrD strains expressing the various sdrD gene variants, indicated a significant difference between only two complements while others showed no major difference in their adhesion. Conclusions This study provides evidence of sequence variations across the different domains of SdrD from S. aureus isolated from healthy nasal carriers. Proper understanding of these variations is necessary in the study of S. aureus pathogenesis. Electronic supplementary material The online version of this article (10.1186/s12866-018-1179-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Clement Ajayi
- Research group of Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037, Tromsø, Norway.
| | - Espen Åberg
- Research group of Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037, Tromsø, Norway
| | - Fatemeh Askarian
- Research group of Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037, Tromsø, Norway
| | - Johanna U E Sollid
- Research group of Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037, Tromsø, Norway
| | - Mona Johannessen
- Research group of Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037, Tromsø, Norway
| | - Anne-Merethe Hanssen
- Research group of Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037, Tromsø, Norway.
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19
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Low LY, Harrison PF, Gould J, Powell DR, Choo JM, Forster SC, Chapman R, Gearing LJ, Cheung JK, Hertzog P, Rood JI. Concurrent Host-Pathogen Transcriptional Responses in a Clostridium perfringens Murine Myonecrosis Infection. mBio 2018; 9:e00473-18. [PMID: 29588405 PMCID: PMC5874911 DOI: 10.1128/mbio.00473-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 03/01/2018] [Indexed: 11/20/2022] Open
Abstract
To obtain an insight into host-pathogen interactions in clostridial myonecrosis, we carried out comparative transcriptome analysis of both the bacterium and the host in a murine Clostridium perfringens infection model, which is the first time that such an investigation has been conducted. Analysis of the host transcriptome from infected muscle tissues indicated that many genes were upregulated compared to the results seen with mock-infected mice. These genes were enriched for host defense pathways, including Toll-like receptor (TLR) and Nod-like receptor (NLR) signaling components. Real-time PCR confirmed that host TLR2 and NLRP3 inflammasome genes were induced in response to C. perfringens infection. Comparison of the transcriptome of C. perfringens cells from the infected tissues with that from broth cultures showed that host selective pressure induced a global change in C. perfringens gene expression. A total of 33% (923) of C. perfringens genes were differentially regulated, including 10 potential virulence genes that were upregulated relative to their expression in vitro These genes encoded putative proteins that may be involved in the synthesis of cell wall-associated macromolecules, in adhesion to host cells, or in protection from host cationic antimicrobial peptides. This report presents the first successful expression profiling of coregulated transcriptomes of bacterial and host genes during a clostridial myonecrosis infection and provides new insights into disease pathogenesis and host-pathogen interactions.IMPORTANCEClostridium perfringens is the causative agent of traumatic clostridial myonecrosis, or gas gangrene. In this study, we carried out transcriptional analysis of both the host and the bacterial pathogen in a mouse myonecrosis infection. The results showed that in comparison to mock-infected control tissues, muscle tissues from C. perfringens-infected mice had a significantly altered gene expression profile. In particular, the expression of many genes involved in the innate immune system was upregulated. Comparison of the expression profiles of C. perfringens cells isolated from the infected tissues with those from equivalent broth cultures identified many potential virulence genes that were significantly upregulated in vivo These studies have provided a new understanding of the range of factors involved in host-pathogen interactions in a myonecrosis infection.
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Affiliation(s)
- Lee-Yean Low
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
| | - Paul F Harrison
- Monash Bioinformatics Platform, Monash University, Clayton, Australia
| | - Jodee Gould
- Department of Molecular and Translational Science, Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, School of Clinical Science, Monash University, Clayton, Australia
| | - David R Powell
- Monash Bioinformatics Platform, Monash University, Clayton, Australia
| | - Jocelyn M Choo
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
| | - Samuel C Forster
- Department of Molecular and Translational Science, Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, School of Clinical Science, Monash University, Clayton, Australia
| | - Ross Chapman
- Department of Molecular and Translational Science, Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, School of Clinical Science, Monash University, Clayton, Australia
| | - Linden J Gearing
- Department of Molecular and Translational Science, Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, School of Clinical Science, Monash University, Clayton, Australia
| | - Jackie K Cheung
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
| | - Paul Hertzog
- Department of Molecular and Translational Science, Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, School of Clinical Science, Monash University, Clayton, Australia
| | - Julian I Rood
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
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20
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Abstract
PURPOSE OF REVIEW Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin disorder that is a major public health burden worldwide. AD lesions are often colonized by Staphylococcus aureus and Staphylococcus epidermidis. An important aspect of Staphylococcus spp. is their propensity to form biofilms, adhesive surface-attached colonies that become highly resistant to antibiotics and immune responses, and recent studies have found that clinical isolates colonizing AD skin are often biofilm-positive. Biofilm formation results in complex bacterial communities that have unique effects on keratinocytes and host immunity. This review will summarize recent studies exploring the role of staphyloccocal biofilms in atopic dermatitis and the implications for treatment. RECENT FINDINGS Recent studies suggest an important role for biofilms in the pathogenesis of numerous dermatologic diseases including AD. S. aureus biofilms have been found to colonize the eccrine ducts of AD skin, and these biofilms influence secretion of keratinocyte cytokines and trigger differentiation and apoptosis of keratinocytes. These activities may act to disrupt barrier function and promote disease pathogenesis as well as allergen sensitization. Formation of biofilm is a successful strategy that protects the bacteria from environmental danger, antibiotics, and phagocytosis, enabling chronic persistence in the host. An increasing number of S. aureus skin isolates are resistant to conventional antibiotics, and staphylococcal biofilm communities are prevalent on the skin of individuals with AD. Staphylococcal colonization of the skin impacts skin barrier function and plays multiple important roles in AD pathogenesis.
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21
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Abstract
The staphylococci comprise a diverse genus of Gram-positive, nonmotile commensal organisms that inhabit the skin and mucous membranes of humans and other mammals. In general, staphylococci are benign members of the natural flora, but many species have the capacity to be opportunistic pathogens, mainly infecting individuals who have medical device implants or are otherwise immunocompromised. Staphylococcus aureus and Staphylococcus epidermidis are major sources of hospital-acquired infections and are the most common causes of surgical site infections and medical device-associated bloodstream infections. The ability of staphylococci to form biofilms in vivo makes them highly resistant to chemotherapeutics and leads to chronic diseases. These biofilm infections include osteomyelitis, endocarditis, medical device infections, and persistence in the cystic fibrosis lung. Here, we provide a comprehensive analysis of our current understanding of staphylococcal biofilm formation, with an emphasis on adhesins and regulation, while also addressing how staphylococcal biofilms interact with the immune system. On the whole, this review will provide a thorough picture of biofilm formation of the staphylococcus genus and how this mode of growth impacts the host.
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22
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Hiding in plain sight: immune evasion by the staphylococcal protein SdrE. Biochem J 2017; 474:1803-1806. [PMID: 28490660 DOI: 10.1042/bcj20170132] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 04/12/2017] [Accepted: 04/18/2017] [Indexed: 11/17/2022]
Abstract
The human immune system is responsible for identification and destruction of invader cells, such as the bacterial pathogen Staphylococcus aureus In response, S. aureus brings to the fight a large number of virulence factors, including several that allow it to evade the host immune response. The staphylococcal surface protein SdrE was recently reported to bind to complement Factor H, an important regulator of complement activation. Factor H attaches to the surface of host cells to inhibit complement activation and amplification, preventing the destruction of the host cell. SdrE binding to Factor H allows S. aureus to mimic a host cell and reduces bacterial killing by granulocytes. In a new study published in Biochemical Journal, Zhang et al. describe crystal structures of SdrE and its complex with the C-terminal portion of Factor H. The structure of SdrE and its interaction with the Factor H peptide closely resemble a family of surface proteins that recognize extracellular matrix components such as fibrinogen. However, unbound SdrE forms a novel 'Closed' conformation with an occluded peptide-binding groove. These structures reveal a fascinating mechanism for immune evasion and provide a potential avenue for the development of novel antimicrobial agents to target SdrE.
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23
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Feuillie C, Formosa-Dague C, Hays LMC, Vervaeck O, Derclaye S, Brennan MP, Foster TJ, Geoghegan JA, Dufrêne YF. Molecular interactions and inhibition of the staphylococcal biofilm-forming protein SdrC. Proc Natl Acad Sci U S A 2017; 114:3738-3743. [PMID: 28320940 PMCID: PMC5389287 DOI: 10.1073/pnas.1616805114] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Staphylococcus aureus forms biofilms on indwelling medical devices using a variety of cell-surface proteins. There is growing evidence that specific homophilic interactions between these proteins represent an important mechanism of cell accumulation during biofilm formation, but the underlying molecular mechanisms are still not well-understood. Here we report the direct measurement of homophilic binding forces by the serine-aspartate repeat protein SdrC and their inhibition by a peptide. Using single-cell and single-molecule force measurements, we find that SdrC is engaged in low-affinity homophilic bonds that promote cell-cell adhesion. Low-affinity intercellular adhesion may play a role in favoring biofilm dynamics. We show that SdrC also mediates strong cellular interactions with hydrophobic surfaces, which are likely to be involved in the initial attachment to biomaterials, the first stage of biofilm formation. Furthermore, we demonstrate that a peptide derived from β-neurexin is a powerful competitive inhibitor capable of efficiently blocking surface attachment, homophilic adhesion, and biofilm accumulation. Molecular modeling suggests that this blocking activity may originate from binding of the peptide to a sequence of SdrC involved in homophilic interactions. Our study opens up avenues for understanding the role of homophilic interactions in staphylococcal adhesion, and for the design of new molecules to prevent biofilm formation during infection.
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Affiliation(s)
- Cécile Feuillie
- Institute of Life Sciences, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Cécile Formosa-Dague
- Institute of Life Sciences, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Leanne M C Hays
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
| | - Ophélie Vervaeck
- Institute of Life Sciences, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Sylvie Derclaye
- Institute of Life Sciences, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Marian P Brennan
- Molecular and Cellular Therapeutics, Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | - Timothy J Foster
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
| | - Joan A Geoghegan
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland;
| | - Yves F Dufrêne
- Institute of Life Sciences, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium;
- Walloon Excellence in Life Sciences and Biotechnology (WELBIO), 1300 Wavre, Belgium
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Luo M, Zhang X, Zhang S, Zhang H, Yang W, Zhu Z, Chen K, Bai L, Wei J, Huang A, Wang D. Crystal Structure of an Invasivity-Associated Domain of SdrE in S. aureus. PLoS One 2017; 12:e0168814. [PMID: 28125581 PMCID: PMC5268492 DOI: 10.1371/journal.pone.0168814] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 12/06/2016] [Indexed: 12/04/2022] Open
Abstract
The surface protein SdrE, a microbial surface components recognizing adhesive matrix molecule (MSCRAMM) family protein expressed on the surface of Staphylococcus aureus (S. aureus), can recognize human complement regulator Factor H and C4BP, thus making it a potentially promising vaccine candidate. In this study, SdrE278-591 was found to directly affect S. aureus host cell invasion. Additionally, the crystal structure of SdrE278-591 at a resolution of 1.25 Å was established, with the three-dimensional structure revealing N2-N3 domains which fold in a manner similar to an IgG fold. Furthermore, a putative ligand binding site located at a conserved charged groove formed by the interface between N2 and N3 domains was identified, with β2 suspected to occupy the ligand recognizing site and undergo a structural rearrangement to allow ligand binding. Overall, these findings have further contributed to the understanding of SdrE as a key factor for S. aureus invasivity and will enable a better understanding of bacterial infection processes.
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Affiliation(s)
- Miao Luo
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, PR China
- Department of Laboratory Medicine, People’s Hospital of YuBei District, YuBei District, Chongqing, People’s Republic of China
| | - Xiang Zhang
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, PR China
| | - Shaocheng Zhang
- Department of Laboratory Medicine, Chongqing Medical University, YixueYuanlu-1, Chongqing, People’s Republic of China
| | - Hongpeng Zhang
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, PR China
| | - Wei Yang
- Department of Laboratory Medicine, Hospital of Zhejiang, Xihu District, Hangzhou, People’s Republic of China
| | - Zhongliang Zhu
- School of Life Science, the University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| | - Ke Chen
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, PR China
| | - Lei Bai
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, PR China
| | - Jie Wei
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, PR China
| | - Ailong Huang
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, PR China
| | - Deqiang Wang
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, PR China
- Department of Laboratory Medicine, Chongqing Medical University, YixueYuanlu-1, Chongqing, People’s Republic of China
- * E-mail:
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Serine-Aspartate Repeat Protein D Increases Staphylococcus aureus Virulence and Survival in Blood. Infect Immun 2016; 85:IAI.00559-16. [PMID: 27795358 PMCID: PMC5203653 DOI: 10.1128/iai.00559-16] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 10/08/2016] [Indexed: 12/17/2022] Open
Abstract
Staphylococcus aureus expresses a panel of cell wall-anchored adhesins, including proteins belonging to the microbial surface components recognizing adhesive matrix molecule (MSCRAMM) family, exemplified by the serine-aspartate repeat protein D (SdrD), which serve key roles in colonization and infection. Deletion of sdrD from S. aureus subsp. aureus strain NCTC8325-4 attenuated bacterial survival in human whole blood ex vivo, which was associated with increased killing by human neutrophils. Remarkably, SdrD was able to inhibit innate immune-mediated bacterial killing independently of other S. aureus proteins, since addition of recombinant SdrD protein and heterologous expression of SdrD in Lactococcus lactis promoted bacterial survival in human blood. SdrD contributes to bacterial virulence in vivo, since fewer S. aureus subsp. aureus NCTC8325-4 ΔsdrD bacteria than bacteria of the parent strain were recovered from blood and several organs using a murine intravenous infection model. Collectively, our findings reveal a new property of SdrD as an important key contributor to S. aureus survival and the ability to escape the innate immune system in blood.
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Wang Y, Wei Y, Yuan S, Tao H, Dong J, Zhang Z, Tian W, Liu C. Bacillus anthracis S-layer protein BslA binds to extracellular matrix by interacting with laminin. BMC Microbiol 2016; 16:183. [PMID: 27514510 PMCID: PMC4981971 DOI: 10.1186/s12866-016-0802-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 08/04/2016] [Indexed: 01/27/2023] Open
Abstract
Background The Bacillus anthracis S-layer protein, BslA, plays a crucial role in mammalian infection. BslA is required to mediate adherence between host cells and vegetative forms of bacteria and this interaction promotes target organs adherence and blood–brain barrier (BBB) penetration in vivo. This study attempts to identify the potential eukaryotic ligand(s) for B. anthracis BslA protein. Results Biochemical approaches have indicated that the putative host cell ligand(s) for BslA is a surface protein, which is independent of the sugar components for binding to Bs1A. A ligand screening using blot overlays, far Western blots and mass spectrometry analyses revealed that BslA binds to mammalian laminin. ELISA based solid-phase binding assays and surface plasmon resonance assays demonstrated that there were high affinity interactions between BslA(260–652) and laminin. The SPR results also revealed the dissociation constants values of 3.172 × 10−9M for the binding of BslA(260–652) to laminin. Conclusions These data demonstrated that laminin is a ligand for BslA. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0802-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yanchun Wang
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, Beijng, 100071, China.
| | - Ying Wei
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, Beijng, 100071, China.,School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Shengling Yuan
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, Beijng, 100071, China
| | - Haoxia Tao
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, Beijng, 100071, China
| | - Jie Dong
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, Beijng, 100071, China
| | - Zhaoshan Zhang
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, Beijng, 100071, China
| | - Wei Tian
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Chunjie Liu
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, Beijng, 100071, China.
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Moche M, Schlüter R, Bernhardt J, Plate K, Riedel K, Hecker M, Becher D. Time-Resolved Analysis of Cytosolic and Surface-Associated Proteins of Staphylococcus aureus HG001 under Planktonic and Biofilm Conditions. J Proteome Res 2015; 14:3804-22. [DOI: 10.1021/acs.jproteome.5b00148] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Martin Moche
- Institute for Microbiology, Ernst-Moritz-Arndt-University, Friedrich-Ludwig-Jahn-Straße
15, 17487 Greifswald, Germany
| | - Rabea Schlüter
- Institute for Microbiology, Ernst-Moritz-Arndt-University, Friedrich-Ludwig-Jahn-Straße
15, 17487 Greifswald, Germany
| | - Jörg Bernhardt
- Institute for Microbiology, Ernst-Moritz-Arndt-University, Friedrich-Ludwig-Jahn-Straße
15, 17487 Greifswald, Germany
| | - Kristina Plate
- Institute for Microbiology, Ernst-Moritz-Arndt-University, Friedrich-Ludwig-Jahn-Straße
15, 17487 Greifswald, Germany
| | - Katharina Riedel
- Institute for Microbiology, Ernst-Moritz-Arndt-University, Friedrich-Ludwig-Jahn-Straße
15, 17487 Greifswald, Germany
| | - Michael Hecker
- Institute for Microbiology, Ernst-Moritz-Arndt-University, Friedrich-Ludwig-Jahn-Straße
15, 17487 Greifswald, Germany
| | - Dörte Becher
- Institute for Microbiology, Ernst-Moritz-Arndt-University, Friedrich-Ludwig-Jahn-Straße
15, 17487 Greifswald, Germany
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28
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Galloway-Peña JR, Liang X, Singh KV, Yadav P, Chang C, La Rosa SL, Shelburne S, Ton-That H, Höök M, Murray BE. The identification and functional characterization of WxL proteins from Enterococcus faecium reveal surface proteins involved in extracellular matrix interactions. J Bacteriol 2015; 197:882-92. [PMID: 25512313 PMCID: PMC4325096 DOI: 10.1128/jb.02288-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 12/10/2014] [Indexed: 11/20/2022] Open
Abstract
The WxL domain recently has been identified as a novel cell wall binding domain found in numerous predicted proteins within multiple Gram-positive bacterial species. However, little is known about the function of proteins containing this novel domain. Here, we identify and characterize 6 Enterococcus faecium proteins containing the WxL domain which, by reverse transcription-PCR (RT-PCR) and genomic analyses, are located in three similarly organized operons, deemed WxL loci A, B, and C. Western blotting, electron microscopy, and enzyme-linked immunosorbent assays (ELISAs) determined that genes of WxL loci A and C encode antigenic, cell surface proteins exposed at higher levels in clinical isolates than in commensal isolates. Secondary structural analyses of locus A recombinant WxL domain-containing proteins found they are rich in β-sheet structure and disordered segments. Using Biacore analyses, we discovered that recombinant WxL proteins from locus A bind human extracellular matrix proteins, specifically type I collagen and fibronectin. Proteins encoded by locus A also were found to bind to each other, suggesting a novel cell surface complex. Furthermore, bile salt survival assays and animal models using a mutant from which all three WxL loci were deleted revealed the involvement of WxL operons in bile salt stress and endocarditis pathogenesis. In summary, these studies extend our understanding of proteins containing the WxL domain and their potential impact on colonization and virulence in E. faecium and possibly other Gram-positive bacterial species.
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Affiliation(s)
- Jessica R Galloway-Peña
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas, USA Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA Center for the Study of Emerging and Re-emerging Pathogens, University of Texas Health Science Center, Houston, Texas, USA
| | - Xiaowen Liang
- Center for Infectious and Inflammatory Diseases, Institute for Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, USA
| | - Kavindra V Singh
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA Center for the Study of Emerging and Re-emerging Pathogens, University of Texas Health Science Center, Houston, Texas, USA
| | - Puja Yadav
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas, USA Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA Center for the Study of Emerging and Re-emerging Pathogens, University of Texas Health Science Center, Houston, Texas, USA
| | - Chungyu Chang
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas, USA
| | - Sabina Leanti La Rosa
- Department of Chemistry, Biotechnology and Food Science, Laboratory of Microbial Gene Technology and Food Microbiology, The Norwegian University of Life Sciences, Aas, Norway
| | - Samuel Shelburne
- Department of Infectious Diseases, Infection Control and Employee Health, M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Hung Ton-That
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas, USA
| | - Magnus Höök
- Center for Infectious and Inflammatory Diseases, Institute for Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, USA
| | - Barbara E Murray
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas, USA Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA Center for the Study of Emerging and Re-emerging Pathogens, University of Texas Health Science Center, Houston, Texas, USA
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29
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Differential expression and roles of Staphylococcus aureus virulence determinants during colonization and disease. mBio 2015; 6:e02272-14. [PMID: 25691592 PMCID: PMC4337569 DOI: 10.1128/mbio.02272-14] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Staphylococcus aureus is a Gram-positive, commensal bacterium known to asymptomatically colonize the human skin, nares, and gastrointestinal tract. Colonized individuals are at increased risk for developing S. aureus infections, which range from mild skin and soft tissue infections to more severe diseases, such as endocarditis, bacteremia, sepsis, and osteomyelitis. Different virulence factors are required for S. aureus to infect different body sites. In this study, virulence gene expression was analyzed in two S. aureus isolates during nasal colonization, bacteremia and in the heart during sepsis. These models were chosen to represent the stepwise progression of S. aureus from an asymptomatic colonizer to an invasive pathogen. Expression of 23 putative S. aureus virulence determinants, representing protein and carbohydrate adhesins, secreted toxins, and proteins involved in metal cation acquisition and immune evasion were analyzed. Consistent upregulation of sdrC, fnbA, fhuD, sstD, and hla was observed in the shift between colonization and invasive pathogen, suggesting a prominent role for these genes in staphylococcal pathogenesis. Finally, gene expression data were correlated to the roles of the genes in pathogenesis by using knockout mutants in the animal models. These results provide insights into how S. aureus modifies virulence gene expression between commensal and invasive pathogens. Many bacteria, such as Staphylococcus aureus, asymptomatically colonize human skin and nasal passages but can also cause invasive diseases, such as bacteremia, pneumonia, sepsis, and osteomyelitis. The goal of this study was to analyze differences in the expression of selected S. aureus genes during a commensal lifestyle and as an invasive pathogen to gain insight into the commensal-to-pathogen transition and how a bacterial pathogen adapts to different environments within a host (e.g., from nasal colonization to invasive pathogen). The gene expression data were also used to select genes for which to construct knockout mutants to assess the role of several proteins in nasal colonization and lethal bacteremia. These results not only provide insight into the factors involved in S. aureus disease pathogenesis but also provide potential therapeutic targets.
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Zhi H, Weening EH, Barbu EM, Hyde JA, Höök M, Skare JT. The BBA33 lipoprotein binds collagen and impacts Borrelia burgdorferi pathogenesis. Mol Microbiol 2015; 96:68-83. [PMID: 25560615 DOI: 10.1111/mmi.12921] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2015] [Indexed: 12/14/2022]
Abstract
Borrelia burgdorferi, the etiologic agent of Lyme disease, adapts to the mammalian hosts by differentially expressing several genes in the BosR and Rrp2-RpoN-RpoS dependent pathways, resulting in a distinct protein profile relative to that seen for survival in the Ixodes spp. tick. Previous studies indicate that a putative lipoprotein, BBA33, is produced in an RpoS-dependent manner under conditions that mimic the mammalian component of the borrelial lifecycle. However, the significance and function for BBA33 is not known. Given its linkage to the BosR/Rrp2-RpoN-RpoS regulatory cascade, we hypothesized that BBA33 facilitates B. burgdorferi infection in the mammalian host. The deletion of bba33 eliminated B. burgdorferi infectivity in C3H mice, which was rescued by genetic complementation with intact bba33. With regard to function, a combinatorial peptide approach, coupled with subsequent in vitro binding assays, indicated that BBA33 binds to collagen type VI and, to a lesser extent, collagen type IV. Whole cell binding assays demonstrated BBA33-dependent binding to human collagen type VI. Taken together, these results suggest that BBA33 interacts with collagenous structures and may function as an adhesin in a process that is required to prevent bacterial clearance.
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Affiliation(s)
- Hui Zhi
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M Health Science Center, Bryan, TX, 77807, USA
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31
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Cell Wall-Anchored Surface Proteins of Staphylococcus aureus: Many Proteins, Multiple Functions. Curr Top Microbiol Immunol 2015; 409:95-120. [PMID: 26667044 DOI: 10.1007/82_2015_5002] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Staphylococcus aureus persistently colonizes about 20 % of the population and is intermittently associated with the remainder. The organism can cause superficial skin infections and life-threatening invasive diseases. The surface of the bacterial cell displays a variety of proteins that are covalently anchored to peptidoglycan. They perform many functions including adhesion to host cells and tissues, invasion of non-phagocytic cells, and evasion of innate immune responses. The proteins have been categorized into distinct classes based on structural and functional analysis. Many surface proteins are multifunctional. Cell wall-anchored proteins perform essential functions supporting survival and proliferation during the commensal state and during invasive infections. The ability of cell wall-anchored proteins to bind to desquamated epithelial cells is important during colonization, and the binding to fibrinogen is of particular significance in pathogenesis.
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32
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Hanses F, Roux C, Dunman PM, Salzberger B, Lee JC. Staphylococcus aureus gene expression in a rat model of infective endocarditis. Genome Med 2014; 6:93. [PMID: 25392717 PMCID: PMC4228149 DOI: 10.1186/s13073-014-0093-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 10/20/2014] [Indexed: 01/04/2023] Open
Abstract
Background Diabetes mellitus is a frequent underlying comorbidity in patients with Staphylococcus aureus endocarditis, and it represents a risk factor for complications and a negative outcome. The pathogenesis of staphylococcal endocardial infections in diabetic hosts has been poorly characterized, and little is known about S. aureus gene expression in endocardial vegetations. Methods We utilized a rat model of experimental S. aureus endocarditis to compare the pathogenesis of staphylococcal infection in diabetic and nondiabetic hosts and to study the global S. aureus transcriptome in endocardial vegetations in vivo. Results Diabetic rats had higher levels of bacteremia and larger endocardial vegetations than nondiabetic control animals. Microarray analyses revealed that 61 S. aureus genes were upregulated in diabetic rats, and the majority of these bacterial genes were involved in amino acid and carbohydrate metabolism. When bacterial gene expression in vivo (diabetic or nondiabetic endocardial vegetations) was compared to in vitro growth conditions, higher in vivo expression of genes encoding toxins and proteases was observed. Additionally, genes involved in the production of adhesins, capsular polysaccharide, and siderophores, as well as in amino acid and carbohydrate transport and metabolism, were upregulated in endocardial vegetations. To test the contribution of selected upregulated genes to the pathogenesis of staphylococcal endocarditis, isogenic deletion mutants were utilized. A mutant defective in production of the siderophore staphyloferrin B was attenuated in the endocarditis model, whereas the virulence of a surface adhesin (ΔsdrCDE) mutant was similar to that of the parental S. aureus strain. Conclusions Our results emphasize the relevance of diabetes mellitus as a risk factor for infectious endocarditis and provide a basis for understanding gene expression during staphylococcal infections in vivo. Electronic supplementary material The online version of this article (doi:10.1186/s13073-014-0093-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Frank Hanses
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115 USA ; Department of Internal Medicine I, University Hospital Regensburg, Franz-Josef-Strauss Allee 11, Regensburg, 93049 Germany
| | - Christelle Roux
- Department of Microbiology and Immunology, University of Rochester, Rochester, NY 14642 USA
| | - Paul M Dunman
- Department of Microbiology and Immunology, University of Rochester, Rochester, NY 14642 USA
| | - Bernd Salzberger
- Department of Internal Medicine I, University Hospital Regensburg, Franz-Josef-Strauss Allee 11, Regensburg, 93049 Germany
| | - Jean C Lee
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115 USA
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Jaglic Z, Desvaux M, Weiss A, Nesse LL, Meyer RL, Demnerova K, Schmidt H, Giaouris E, Sipailiene A, Teixeira P, Kačániová M, Riedel CU, Knøchel S. Surface adhesins and exopolymers of selected foodborne pathogens. MICROBIOLOGY-SGM 2014; 160:2561-2582. [PMID: 25217529 DOI: 10.1099/mic.0.075887-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The ability of bacteria to bind different compounds and to adhere to biotic and abiotic surfaces provides them with a range of advantages, such as colonization of various tissues, internalization, avoidance of an immune response, and survival and persistence in the environment. A variety of bacterial surface structures are involved in this process and these promote bacterial adhesion in a more or less specific manner. In this review, we will focus on those surface adhesins and exopolymers in selected foodborne pathogens that are involved mainly in primary adhesion. Their role in biofilm development will also be considered when appropriate. Both the clinical impact and the implications for food safety of such adhesion will be discussed.
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Affiliation(s)
- Zoran Jaglic
- Veterinary Research Institute, Brno, Czech Republic
| | - Mickaël Desvaux
- INRA, UR454 Microbiologie, F-63122 Saint-Genès Champanelle, France
| | - Agnes Weiss
- Department of Food Microbiology, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 28, 70599 Stuttgart, Germany
| | | | - Rikke L Meyer
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Katerina Demnerova
- Institute of Chemical Technology, Faculty of Food and Biochemical Technology, Department of Biochemistry and Microbiology, Technicka 5, Prague, 166 28, Czech Republic
| | - Herbert Schmidt
- Department of Food Microbiology, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 28, 70599 Stuttgart, Germany
| | - Efstathios Giaouris
- Department of Food Science and Nutrition, Faculty of the Environment, University of the Aegean, 81400 Myrina, Lemnos Island, Greece
| | | | - Pilar Teixeira
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | | | - Christian U Riedel
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Susanne Knøchel
- Department of Food Science, University of Copenhagen, Rolighedsvej 30, Frederiksberg C 1958, Denmark
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34
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Barbu EM, Mackenzie C, Foster TJ, Höök M. SdrC induces staphylococcal biofilm formation through a homophilic interaction. Mol Microbiol 2014; 94:172-85. [PMID: 25115812 DOI: 10.1111/mmi.12750] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2014] [Indexed: 02/03/2023]
Abstract
The molecular pathogenesis of many Staphylococcus aureus infections involves growth of bacteria as biofilm. In addition to polysaccharide intercellular adhesin (PIA) and extracellular DNA, surface proteins appear to mediate the transition of bacteria from planktonic growth to sessile lifestyle as well as biofilm growth, and can enable these processes even in the absence of PIA expression. However, the molecular mechanisms by which surface proteins contribute to biofilm formation are incompletely understood. Here we demonstrate that self-association of the serine-aspartate repeat protein SdrC promotes both bacterial adherence to surfaces and biofilm formation. However, this homophilic interaction is not required for the attachment of bacteria to abiotic surfaces. We identified the subdomain that mediates SdrC dimerization and subsequent cell-cell interactions. In addition, we determined that two adjacently located amino acid sequences within this subdomain are required for the SdrC homophilic interaction. Comparative amino acid sequence analysis indicated that these binding sites are conserved. In summary, our study identifies SdrC as a novel molecular determinant in staphylococcal biofilm formation and describes the mechanism responsible for intercellular interactions. Furthermore, these findings contribute to a growing body of evidence suggesting that homophilic interactions between surface proteins present on neighbouring bacteria induce biofilm growth.
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Affiliation(s)
- E Magda Barbu
- Center for Infectious & Inflammatory Diseases, Institute and Bioscience and Technology, Texas A&M Health Science Center, Houston, TX, USA; Department of Infectious Diseases, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
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35
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Foster TJ, Geoghegan JA, Ganesh VK, Höök M. Adhesion, invasion and evasion: the many functions of the surface proteins of Staphylococcus aureus. Nat Rev Microbiol 2014; 12:49-62. [PMID: 24336184 DOI: 10.1038/nrmicro3161] [Citation(s) in RCA: 933] [Impact Index Per Article: 93.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Staphylococcus aureus is an important opportunistic pathogen and persistently colonizes about 20% of the human population. Its surface is 'decorated' with proteins that are covalently anchored to the cell wall peptidoglycan. Structural and functional analysis has identified four distinct classes of surface proteins, of which microbial surface component recognizing adhesive matrix molecules (MSCRAMMs) are the largest class. These surface proteins have numerous functions, including adhesion to and invasion of host cells and tissues, evasion of immune responses and biofilm formation. Thus, cell wall-anchored proteins are essential virulence factors for the survival of S. aureus in the commensal state and during invasive infections, and targeting them with vaccines could combat S. aureus infections.
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Affiliation(s)
- Timothy J Foster
- Microbiology Department, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland
| | - Joan A Geoghegan
- Microbiology Department, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland
| | - Vannakambadi K Ganesh
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas 77030, USA
| | - Magnus Höök
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas 77030, USA
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36
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Becherelli M, Prachi P, Viciani E, Biagini M, Fiaschi L, Chiarot E, Nosari S, Brettoni C, Marchi S, Biancucci M, Fontana MR, Montagnani F, Bagnoli F, Barocchi MA, Manetti AGO. Protective activity of the CnaBE3 domain conserved among Staphylococcus aureus Sdr proteins. PLoS One 2013; 8:e74718. [PMID: 24069334 PMCID: PMC3775735 DOI: 10.1371/journal.pone.0074718] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 08/02/2013] [Indexed: 12/01/2022] Open
Abstract
Staphylococcus aureus is an opportunistic pathogen, commensal of the human skin and nares, but also responsible for invasive nosocomial as well as community acquired infections. Staphylococcus aureus adheres to the host tissues by means of surface adhesins, such as SdrC, SdrD, and SdrE proteins. The Sdr family of proteins together with a functional A domain, contain respectively two, three or five repeated sequences called B motifs which comprise the CnaB domains. SdrD and SdrE proteins were reported to be protective in animal models against invasive diseases or lethal challenge with human clinical S. aureus isolates. In this study we identified a 126 amino acid sequence containing a CnaB domain, conserved among the three Sdr proteins. The three fragments defined here as CnaBC2, D5 and E3 domains even though belonging to phylogenetically distinct strains, displayed high sequence similarity. Based on the sequence conservation data, we selected the CnaBE3 domain for further analysis and characterization. Polyclonal antibodies raised against the recombinant CnaBE3 domain recognized SdrE, SdrC and SdrD proteins of different S. aureus lineages. Moreover, we demonstrated that the CnaBE3 domain was expressed in vivo during S. aureus infections, and that immunization of this domain alone significantly reduces the bacterial load in mice challenged with S. aureus. Furthermore, we show that the reduction of bacteria by CnaBE3 vaccination is due to functional antibodies. Finally, we demonstrated that the region of the SdrE protein containing the CnaBE3 domain was resistant to trypsin digestion, a characteristic often associated with the presence of an isopeptide bond.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Sara Marchi
- Novartis Vaccines and Diagnostics, Siena, Italy
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Uhlemann AC, Kennedy AD, Martens C, Porcella SF, Deleo FR, Lowy FD. Toward an understanding of the evolution of Staphylococcus aureus strain USA300 during colonization in community households. Genome Biol Evol 2013; 4:1275-85. [PMID: 23104992 PMCID: PMC3542572 DOI: 10.1093/gbe/evs094] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Staphylococcus aureus is a frequent cause of serious infections and also a human commensal. The emergence of community-associated methicillin-resistant S. aureus led to a dramatic increase in skin and soft tissue infections worldwide. This epidemic has been driven by a limited number of clones, such as USA300 in the United States. To better understand the extent of USA300 evolution and diversification within communities, we performed comparative whole-genome sequencing of three clinical and five colonizing USA300 isolates collected longitudinally from three unrelated households over a 15-month period. Phylogenetic analysis that incorporated additional geographically diverse USA300 isolates indicated that all but one likely arose from a common recent ancestor. Although limited genetic adaptation occurred over the study period, the greatest genetic heterogeneity occurred between isolates from different households and within one heavily colonized household. This diversity allowed for a more accurate tracking of interpersonal USA300 transmission. Sequencing of persisting USA300 isolates revealed mutations in genes involved in major aspects of S. aureus function: adhesion, cell wall biosynthesis, virulence, and carbohydrate metabolism. Genetic variations also included accumulation of multiple polymorphisms within select genes of two multigene operons, suggestive of small genome rearrangements rather than de novo single point mutations. Such rearrangements have been underappreciated in S. aureus and may represent novel means of strain variation. Subtle genetic changes may contribute to USA300 fitness and persistence. Elucidation of small genome rearrangements reveals a potentially new and intriguing mechanism of directed S. aureus genome diversification in environmental niches and during pathogen-host interactions.
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Affiliation(s)
- Anne-Catrin Uhlemann
- Division of Infectious Diseases, Department of Medicine, Columbia University, College of Physicians & Surgeons, New York, NY, USA.
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Wang X, Ge J, Liu B, Hu Y, Yang M. Structures of SdrD from Staphylococcus aureus reveal the molecular mechanism of how the cell surface receptors recognize their ligands. Protein Cell 2013; 4:277-85. [PMID: 23549613 DOI: 10.1007/s13238-013-3009-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 02/25/2013] [Indexed: 11/25/2022] Open
Abstract
Staphylococcus aureus is the most important Gram-positive colonizer of human skin and nasal passage, causing high morbidity and mortality. SD-repeat containing protein D (SdrD), an MSCRAMM (Microbial Surface Components Recognizing Adhesive Matrix Molecules) family surface protein, plays an important role in S. aureus adhesion and pathogenesis, while its binding target and molecular mechanism remain largely unknown. Here we solved the crystal structures of SdrD N2-N3 domain and N2-N3-B1 domain. Through structural analysis and comparisons, we characterized the ligand binding site of SdrD, and proposed a featured sequence motif of its potential ligands. In addition, the structures revealed for the first time the interactions between B1 domain and N2-N3 domain among B domain-containing MSCRAMMs. Our results may help in understanding the roles SdrD plays in S. aureus adhesion and shed light on the development of novel antibiotics.
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Affiliation(s)
- Xiao Wang
- Key Laboratory for Protein Sciences of Ministry of Education, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
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Ross CL, Liang X, Liu Q, Murray BE, Höök M, Ganesh VK. Targeted protein engineering provides insights into binding mechanism and affinities of bacterial collagen adhesins. J Biol Chem 2012; 287:34856-65. [PMID: 22865854 DOI: 10.1074/jbc.m112.371054] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The collagen-binding bacterial proteins, Ace and Cna, are well characterized on the biochemical and structural level. Despite overall structural similarity, recombinant forms of the Ace and Cna ligand-binding domains exhibit significantly different affinities and binding kinetics for collagen type I (CI) in vitro. In this study, we sought to understand, in submolecular detail, the bases for these differences. Using a structure-based approach, we engineered Cna and Ace variants by altering specific structural elements within the ligand-binding domains. Surface plasmon resonance-based binding analysis demonstrated that mutations that are predicted to alter the orientation of the Ace and Cna N(1) and N(2) subdomains significantly affect the interaction between the MSCRAMM (microbial surface components recognizing adhesive matrix molecule) and CI in vitro, including affinity, association/dissociation rates and binding ratio. Moreover, we utilized this information to engineer an Ace variant with an 11,000-fold higher CI affinity than the parent protein. Finally, we noted that several engineered proteins that exhibited a weak interaction with CI recognized more sites on CI, suggesting an inverse correlation between affinity and specificity.
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Affiliation(s)
- Caná L Ross
- Center for Inflammatory and Infectious Disease, Institute for Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, USA
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Development of anti-infectives using phage display: biological agents against bacteria, viruses, and parasites. Antimicrob Agents Chemother 2012; 56:4569-82. [PMID: 22664969 DOI: 10.1128/aac.00567-12] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The vast majority of anti-infective therapeutics on the market or in development are small molecules; however, there is now a nascent pipeline of biological agents in development. Until recently, phage display technologies were used mainly to produce monoclonal antibodies (MAbs) targeted against cancer or inflammatory disease targets. Patent disputes impeded broad use of these methods and contributed to the dearth of candidates in the clinic during the 1990s. Today, however, phage display is recognized as a powerful tool for selecting novel peptides and antibodies that can bind to a wide range of antigens, ranging from whole cells to proteins and lipid targets. In this review, we highlight research that exploits phage display technology as a means of discovering novel therapeutics against infectious diseases, with a focus on antimicrobial peptides and antibodies in clinical or preclinical development. We discuss the different strategies and methods used to derive, select, and develop anti-infectives from phage display libraries and then highlight case studies of drug candidates in the process of development and commercialization. Advances in screening, manufacturing, and humanization technologies now mean that phage display can make a significant contribution in the fight against clinically important pathogens.
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Miyazaki S, Matsumoto Y, Sekimizu K, Kaito C. Evaluation of Staphylococcus aureus virulence factors using a silkworm model. FEMS Microbiol Lett 2011; 326:116-24. [PMID: 22092964 DOI: 10.1111/j.1574-6968.2011.02439.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 08/29/2011] [Accepted: 10/17/2011] [Indexed: 02/04/2023] Open
Abstract
Previous studies have indicated that the silkworm model is useful for identifying virulence genes of Staphylococcus aureus, a human pathogenic bacterium. Here we examined the scope of S. aureus virulence factors that can be evaluated using the silkworm model. Gene-disrupted mutants of the agr locus, arlS gene and saeS gene, which regulate the expression of cell surface adhesins and hemolysins, exhibited attenuated virulence in silkworms. Mutants of the hla gene encoding α-hemolysin, the hlb gene encoding β-hemolysin, and the psmα and psmβ operons encoding cytolysins, however, showed virulence in silkworms indistinguishable from that of the parent strain. Thus, these S. aureus cytolysins are not required for virulence in silkworms. In contrast, the gene-disrupted mutants of clfB, fnbB and sdrC, which encode cell-wall-anchored proteins, attenuated S. aureus virulence in silkworms. In addition, the mutant of the srtA gene encoding sortase A, which anchors cell-wall proteins, showed attenuated virulence in silkworms. These findings suggest that the silkworm model can be used to evaluate S. aureus cell-wall proteins and regulatory proteins as virulence factors.
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Affiliation(s)
- Shinya Miyazaki
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan
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Montanaro L, Speziale P, Campoccia D, Ravaioli S, Cangini I, Pietrocola G, Giannini S, Arciola CR. Scenery ofStaphylococcusimplant infections in orthopedics. Future Microbiol 2011; 6:1329-49. [DOI: 10.2217/fmb.11.117] [Citation(s) in RCA: 264] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Adhesive polypeptides of Staphylococcus aureus identified using a novel secretion library technique in Escherichia coli. BMC Microbiol 2011; 11:117. [PMID: 21615970 PMCID: PMC3127751 DOI: 10.1186/1471-2180-11-117] [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] [Received: 01/14/2011] [Accepted: 05/27/2011] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Bacterial adhesive proteins, called adhesins, are frequently the decisive factor in initiation of a bacterial infection. Characterization of such molecules is crucial for the understanding of bacterial pathogenesis, design of vaccines and development of antibacterial drugs. Because adhesins are frequently difficult to express, their characterization has often been hampered. Alternative expression methods developed for the analysis of adhesins, e.g. surface display techniques, suffer from various drawbacks and reports on high-level extracellular secretion of heterologous proteins in Gram-negative bacteria are scarce. These expression techniques are currently a field of active research. The purpose of the current study was to construct a convenient, new technique for identification of unknown bacterial adhesive polypeptides directly from the growth medium of the Escherichia coli host and to identify novel proteinaceous adhesins of the model organism Staphylococcus aureus. RESULTS Randomly fragmented chromosomal DNA of S. aureus was cloned into a unique restriction site of our expression vector, which facilitates secretion of foreign FLAG-tagged polypeptides into the growth medium of E. coli ΔfliCΔfliD, to generate a library of 1663 clones expressing FLAG-tagged polypeptides. Sequence and bioinformatics analyses showed that in our example, the library covered approximately 32% of the S. aureus proteome. Polypeptides from the growth medium of the library clones were screened for binding to a selection of S. aureus target molecules and adhesive fragments of known staphylococcal adhesins (e.g coagulase and fibronectin-binding protein A) as well as polypeptides of novel function (e.g. a universal stress protein and phosphoribosylamino-imidazole carboxylase ATPase subunit) were detected. The results were further validated using purified His-tagged recombinant proteins of the corresponding fragments in enzyme-linked immunoassay and surface plasmon resonance analysis. CONCLUSIONS A new technique for identification of unknown bacterial adhesive polypeptides was constructed. Application of the method on S. aureus allowed us to identify three known adhesins and in addition, five new polypeptides binding to human plasma and extracellular matrix proteins. The method, here used on S. aureus, is convenient due to the use of soluble proteins from the growth medium and can in principle be applied to any bacterial species of interest.
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Sequence diversities of serine-aspartate repeat genes among Staphylococcus aureus isolates from different hosts presumably by horizontal gene transfer. PLoS One 2011; 6:e20332. [PMID: 21625460 PMCID: PMC3098876 DOI: 10.1371/journal.pone.0020332] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Accepted: 04/27/2011] [Indexed: 11/25/2022] Open
Abstract
Background Horizontal gene transfer (HGT) is recognized as one of the major forces for bacterial genome evolution. Many clinically important bacteria may acquire virulence factors and antibiotic resistance through HGT. The comparative genomic analysis has become an important tool for identifying HGT in emerging pathogens. In this study, the Serine-Aspartate Repeat (Sdr) family has been compared among different sources of Staphylococcus aureus (S. aureus) to discover sequence diversities within their genomes. Methodology/Principal Findings Four sdr genes were analyzed for 21 different S. aureus strains and 218 mastitis-associated S. aureus isolates from Canada. Comparative genomic analyses revealed that S. aureus strains from bovine mastitis (RF122 and mastitis isolates in this study), ovine mastitis (ED133), pig (ST398), chicken (ED98), and human methicillin-resistant S. aureus (MRSA) (TCH130, MRSA252, Mu3, Mu50, N315, 04-02981, JH1 and JH9) were highly associated with one another, presumably due to HGT. In addition, several types of insertion and deletion were found in sdr genes of many isolates. A new insertion sequence was found in mastitis isolates, which was presumably responsible for the HGT of sdrC gene among different strains. Moreover, the sdr genes could be used to type S. aureus. Regional difference of sdr genes distribution was also indicated among the tested S. aureus isolates. Finally, certain associations were found between sdr genes and subclinical or clinical mastitis isolates. Conclusions Certain sdr gene sequences were shared in S. aureus strains and isolates from different species presumably due to HGT. Our results also suggest that the distributional assay of virulence factors should detect the full sequences or full functional regions of these factors. The traditional assay using short conserved regions may not be accurate or credible. These findings have important implications with regard to animal husbandry practices that may inadvertently enhance the contact of human and animal bacterial pathogens.
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Ganesh VK, Barbu EM, Deivanayagam CCS, Le B, Anderson AS, Matsuka YV, Lin SL, Foster TJ, Narayana SVL, Höök M. Structural and biochemical characterization of Staphylococcus aureus clumping factor B/ligand interactions. J Biol Chem 2011; 286:25963-72. [PMID: 21543319 DOI: 10.1074/jbc.m110.217414] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Clumping factor B (ClfB) from Staphylococcus aureus is a bifunctional protein that binds to human cytokeratin 10 (K10) and fibrinogen (Fg). ClfB has been implicated in S. aureus colonization of nasal epithelium and is therefore a key virulence factor. People colonized with S. aureus are at an increased risk for invasive staphylococcal disease. In this study, we have determined the crystal structures of the ligand-binding region of ClfB in an apo-form and in complex with human K10 and Fg α-chain-derived peptides, respectively. We have determined the structures of MSCRAMM binding to two ligands with different sequences in the same site showing the versatile nature of the ligand recognition mode of microbial surface components recognizing adhesive matrix molecules. Both ligands bind ClfB by parallel β-sheet complementation as observed for the clumping factor A·γ-chain peptide complex. The β-sheet complementation is shorter in the ClfB·Fg α-chain peptide complex. The structures show that several residues in ClfB are important for binding to both ligands, whereas others only make contact with one of the ligands. A common motif GSSGXG found in both ligands is part of the ClfB-binding site. This motif is found in many human proteins thus raising the possibility that ClfB recognizes additional ligands.
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Affiliation(s)
- Vannakambadi K Ganesh
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas 77030, USA.
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Heilmann C. Adhesion mechanisms of staphylococci. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 715:105-23. [PMID: 21557060 DOI: 10.1007/978-94-007-0940-9_7] [Citation(s) in RCA: 132] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Staphylococcal adherence to an either biotic or abiotic surface is the critical first event in the establishment of an infection with these serious pathogens. Especially Staphylococcus aureus harbours a variety of proteinaceous and non-proteinaceous adhesins that mediate attachment to a multitude of host factors, such as extracellular matrix and plasma proteins and human host cells, or intercellular adhesion, which is essential for biofilm accumulation. Proteinaceous adhesins may be classified in covalently surface-anchored proteins of the MSCRAMM (microbial surface components recognizing adhesive matrix molecules) family or in proteins that are surface-associated by different means, such as ionic or hydrophobic interactions. Non-covalently surface-associated proteins include the autolysin/adhesins, proteins of the SERAM (secretable expanded repertoire adhesive molecules) family, or membrane-spanning proteins. Non-proteinaceous adhesins comprise the polysaccharide PIA (polysaccharide intercellular adhesin) and wall teichoic and lipoteichoic acids. The features and functions of surface and surface-associated protein adhesins as well as of non-proteinaceous adhesins are discussed.
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Affiliation(s)
- Christine Heilmann
- Institute for Medical Microbiology, University Hospital of Münster, 48149, Münster, Germany.
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Characterization of transcription within sdr region of Staphylococcus aureus. Antonie van Leeuwenhoek 2010; 99:409-16. [PMID: 20571861 PMCID: PMC3032192 DOI: 10.1007/s10482-010-9476-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Accepted: 06/11/2010] [Indexed: 11/13/2022]
Abstract
Staphylococcus aureus is an opportunistic pathogen responsible for various infections in humans and animals. It causes localized and systemic infections, such as abscesses, impetigo, cellulitis, sepsis, endocarditis, bone infections, and meningitis. S. aureus virulence factors responsible for the initial contact with host cells (MSCRAMMs—microbial surface components recognizing adhesive matrix molecules) include three Sdr proteins. The presence of particular sdr genes is correlated with putative tissue specificity. The transcriptional organization of the sdr region remains unclear. We tested expression of the sdrC, sdrD, or sdrE genes in various in vitro conditions, as well as after contact with human blood. In this work, we present data suggesting a separation of the sdr region into three transcriptional units, based on their differential reactions to the environment. Differential reaction of the sdrD transcript to environmental conditions and blood suggests dissimilar functions of the sdr genes. SdrE has been previously proposed to play role in bone infections, whilst our results can indicate that sdrD plays a role in the interactions between the pathogen and human immune system, serum or specifically reacts to nutrients/other factors present in human blood.
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