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Amacher JF, Antos JM. Sortases: structure, mechanism, and implications for protein engineering. Trends Biochem Sci 2024; 49:596-610. [PMID: 38692993 DOI: 10.1016/j.tibs.2024.04.003] [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: 03/22/2024] [Accepted: 04/15/2024] [Indexed: 05/03/2024]
Abstract
Sortase enzymes are critical cysteine transpeptidases on the surface of bacteria that attach proteins to the cell wall and are involved in the construction of bacterial pili. Due to their ability to recognize specific substrates and covalently ligate a range of reaction partners, sortases are widely used in protein engineering applications via sortase-mediated ligation (SML) strategies. In this review, we discuss recent structural studies elucidating key aspects of sortase specificity and the catalytic mechanism. We also highlight select recent applications of SML, including examples where fundamental studies of sortase structure and function have informed the continued development of these enzymes as tools for protein engineering.
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Affiliation(s)
- Jeanine F Amacher
- Department of Chemistry, Western Washington University, Bellingham, WA 98225, USA.
| | - John M Antos
- Department of Chemistry, Western Washington University, Bellingham, WA 98225, USA.
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2
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Soleimani S, Bruce-Tagoe TA, Ullah N, Rippy MG, Spratt HG, Danquah MK. Development and characterization of a portable electrochemical aptasensor for IsdA protein and Staphylococcus aureus detection. Anal Bioanal Chem 2024:10.1007/s00216-024-05410-w. [PMID: 38916796 DOI: 10.1007/s00216-024-05410-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Accepted: 06/14/2024] [Indexed: 06/26/2024]
Abstract
Staphylococcus aureus (S. aureus) is recognized as one of the most common causes of gastroenteritis worldwide. This pathogen is a major foodborne pathogen that can cause many different types of various infections, from minor skin infections to lethal blood infectious diseases. Iron-regulated surface determinant protein A (IsdA) is an important protein on the S. aureus surface. It is responsible for iron scavenging via interaction with hemoglobin, haptoglobin, and hemoglobin-haptoglobin complexes. This study develops a portable aptasensor for IsdA and S. aureus detection using aptamer-modified gold nanoparticles (AuNPs) integrated into screen-printed carbon electrodes (SPCEs). The electrode system was made of three parts, including a carbon counter electrode, an AuNPs/carbon working electrode, and a silver reference electrode. The aptamer by Au-S bonding was conjugated on the electrode surface to create the aptasensor platform. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were utilized to investigate the binding interactions between the aptasensor and the IsdA protein. CV studies showed a linear correlation between varying S. aureus concentrations within the range of 101 to 106 CFU/mL, resulting in a limit of detection (LOD) of 0.2 CFU/mL. The results demonstrated strong reproducibility, selectivity, and sensitivity of the aptasensor for enhanced detection of IsdA, along with about 93% performance stability after 30 days. The capability of the aptasensor to directly detect S. aureus via the IsdA surface protein binding was further investigated in a food matrix. Overall, the aptasensor device showed the potential for rapid detection of S. aureus, serving as a robust approach to developing real-time aptasensors to identify an extensive range of targets of foodborne pathogens and beyond.
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Affiliation(s)
- Shokoufeh Soleimani
- Department of Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee, Knoxville, TN, 37996, USA
| | - Tracy Ann Bruce-Tagoe
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, 37996, USA
| | - Najeeb Ullah
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, 37996, USA
| | - Meredith G Rippy
- Department of Biology, Geology, and Environmental Science, University of Tennessee, Chattanooga, TN, 37403, USA
| | - Henry G Spratt
- Department of Biology, Geology, and Environmental Science, University of Tennessee, Chattanooga, TN, 37403, USA
| | - Michael K Danquah
- Department of Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee, Knoxville, TN, 37996, USA.
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, 37996, USA.
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Kerro Dego O, Vidlund J. Staphylococcal mastitis in dairy cows. Front Vet Sci 2024; 11:1356259. [PMID: 38863450 PMCID: PMC11165426 DOI: 10.3389/fvets.2024.1356259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 05/06/2024] [Indexed: 06/13/2024] Open
Abstract
Bovine mastitis is one of the most common diseases of dairy cattle. Even though different infectious microorganisms and mechanical injury can cause mastitis, bacteria are the most common cause of mastitis in dairy cows. Staphylococci, streptococci, and coliforms are the most frequently diagnosed etiological agents of mastitis in dairy cows. Staphylococci that cause mastitis are broadly divided into Staphylococcus aureus and non-aureus staphylococci (NAS). NAS is mainly comprised of coagulase-negative Staphylococcus species (CNS) and some coagulase-positive and coagulase-variable staphylococci. Current staphylococcal mastitis control measures are ineffective, and dependence on antimicrobial drugs is not sustainable because of the low cure rate with antimicrobial treatment and the development of resistance. Non-antimicrobial effective and sustainable control tools are critically needed. This review describes the current status of S. aureus and NAS mastitis in dairy cows and flags areas of knowledge gaps.
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Affiliation(s)
- Oudessa Kerro Dego
- Department of Animal Science, University of Tennessee, Knoxville, TN, United States
| | - Jessica Vidlund
- Department of Animal Science, University of Tennessee, Knoxville, TN, United States
- East Tennessee AgResearch and Education Center-Little River Animal and Environmental Unit, University of Tennessee, Walland, TN, United States
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4
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Bhattacharya M, Horswill AR. The role of human extracellular matrix proteins in defining Staphylococcus aureus biofilm infections. FEMS Microbiol Rev 2024; 48:fuae002. [PMID: 38337187 PMCID: PMC10873506 DOI: 10.1093/femsre/fuae002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 01/26/2024] [Accepted: 02/07/2024] [Indexed: 02/12/2024] Open
Abstract
Twenty to forty one percent of the world's population is either transiently or permanently colonized by the Gram-positive bacterium, Staphylococcus aureus. In 2017, the CDC designated methicillin-resistant S. aureus (MRSA) as a serious threat, reporting ∼300 000 cases of MRSA-associated hospitalizations annually, resulting in over 19 000 deaths, surpassing that of HIV in the USA. S. aureus is a proficient biofilm-forming organism that rapidly acquires resistance to antibiotics, most commonly methicillin (MRSA). This review focuses on a large group of (>30) S. aureus adhesins, either surface-associated or secreted that are designed to specifically bind to 15 or more of the proteins that form key components of the human extracellular matrix (hECM). Importantly, this includes hECM proteins that are pivotal to the homeostasis of almost every tissue environment [collagen (skin), proteoglycans (lung), hemoglobin (blood), elastin, laminin, fibrinogen, fibronectin, and fibrin (multiple organs)]. These adhesins offer S. aureus the potential to establish an infection in every sterile tissue niche. These infections often endure repeated immune onslaught, developing into chronic, biofilm-associated conditions that are tolerant to ∼1000 times the clinically prescribed dose of antibiotics. Depending on the infection and the immune response, this allows S. aureus to seamlessly transition from colonizer to pathogen by subtly manipulating the host against itself while providing the time and stealth that it requires to establish and persist as a biofilm. This is a comprehensive discussion of the interaction between S. aureus biofilms and the hECM. We provide particular focus on the role of these interactions in pathogenesis and, consequently, the clinical implications for the prevention and treatment of S. aureus biofilm infections.
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Affiliation(s)
- Mohini Bhattacharya
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, United States
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, United States
- Department of Veterans Affairs, Eastern Colorado Health Care System, Aurora, CO 80045, United States
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Hong X, Zhou S, Dai X, Xie D, Cai Y, Zhao G, Li B. Molecular typing and characterization of Staphylococcus aureus isolates from burn wound infections in Fujian, China. Front Microbiol 2023; 14:1236497. [PMID: 37799609 PMCID: PMC10547878 DOI: 10.3389/fmicb.2023.1236497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/30/2023] [Indexed: 10/07/2023] Open
Abstract
Background Staphylococcus aureus (S. aureus) is the most common causative agent of burn wound infection, that often leads to high morbidity and mortality. However, there is not enough knowledge about the molecular epidemiology and antimicrobial susceptibility of S. aureus isolates from burn wound infections in Fujian, China. Methods Between 2016 and 2021, 90 S. aureus isolates were collected from burn wound infections in Fujian, China, including 59 methicillin-resistant (MRSA) strains and 31 methicillin-susceptible (MSSA) strains. These were investigated for molecular characteristics, virulence genes, biofilms, and antimicrobial susceptibility. All the isolates were genotyped by multilocus sequence typing (MLST), spa typing, agr typing, and SCCmec typing. Conventional PCR was performed for the detection of virulence genes. Biofilm formation capacity was assessed by tissue culture plate assay (TCP). The antimicrobial susceptibility of the isolates was evaluated using the dilution method. Results In total, 37 sequence types (ST) and 34 Staphylococcal protein A (spa) types (including a new type named spa-t20720) were identified based on multilocus sequence typing (MLST) and spa typing, respectively. CC8-ST239-t030-agrI-SCCmecIII (57.6%,34/59) and CC7-ST7-t091-agrI (16.1%, 5/31) represented the main clone of MRSA and MSSA isolates, respectively. Antibiotic susceptibility testing identified a significant difference in resistance rates between ST239 and non-ST239 isolates (p < 0.05). Twelve virulence genes were detected, of which the most common were icaA and icaD (both 100%), followed by icaB and icaC (both 96.7%), icaR (95.6%), lukED (81.1%), lukAB (62.2%), pvl (50%), hlgBC (26.7%), and eta (4.4%). Moreover, lukAB, hlgBC, agrI, and agrIII were significantly correlated with burn severity (p < 0.05). MRSA isolates were less likely, compared with MSSA isolates, to carry pvl, lukAB, and hlgBC (p < 0.05). A new spa type, t20720, was identified that contains pvl, lukED, lukAB, hlgBC, icaA, icaB, icaC, icaD, and icaR genes and has strong biofilm formation ability. Conclusion CC8-ST239-t030-agrI-SCCmecIII and CC7-ST-7-t091-agrI were the prevalent molecular signatures of MRSA and MSSA isolates from burn wound infections in Fujian, China, respectively. The newly identified spa-t20720 isolate, which carries a wide range of virulence genes and has strong biofilm formation ability, requires special clinical attention.
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Affiliation(s)
- Xiaolan Hong
- Department of Clinical Laboratory, Fujian Medical University Union Hospital, Fujian, China
- Department of Clinical Laboratory, The 910 Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Fujian, China
| | - Shaobo Zhou
- Department of Clinical Laboratory, The 910 Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Fujian, China
| | - Xubo Dai
- Department of Clinical Laboratory, The 910 Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Fujian, China
| | - Dandan Xie
- Department of Clinical Laboratory, The 910 Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Fujian, China
| | - Yuanyuan Cai
- Department of Clinical Laboratory, The 910 Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Fujian, China
| | - Guimei Zhao
- Department of Clinical Laboratory, The 910 Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Fujian, China
| | - Bin Li
- Department of Clinical Laboratory, Fujian Medical University Union Hospital, Fujian, China
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Lucero B, Francisco KR, Liu LJ, Caffrey CR, Ballatore C. Protein-protein interactions: developing small-molecule inhibitors/stabilizers through covalent strategies. Trends Pharmacol Sci 2023; 44:474-488. [PMID: 37263826 PMCID: PMC11003449 DOI: 10.1016/j.tips.2023.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/15/2023] [Accepted: 04/26/2023] [Indexed: 06/03/2023]
Abstract
The development of small-molecule inhibitors or stabilizers of selected protein-protein interactions (PPIs) of interest holds considerable promise for the development of research tools as well as candidate therapeutics. In this context, the covalent modification of selected residues within the target protein has emerged as a promising mechanism of action to obtain small-molecule modulators of PPIs with appropriate selectivity and duration of action. Different covalent labeling strategies are now available that can potentially allow for a rational, ground-up discovery and optimization of ligands as PPI inhibitors or stabilizers. This review article provides a synopsis of recent developments and applications of such tactics, with a particular focus on site-directed fragment tethering and proximity-enabled approaches.
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Affiliation(s)
- Bobby Lucero
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Karol R Francisco
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Lawrence J Liu
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Conor R Caffrey
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Carlo Ballatore
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
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Schwermann N, Winstel V. Functional diversity of staphylococcal surface proteins at the host-microbe interface. Front Microbiol 2023; 14:1196957. [PMID: 37275142 PMCID: PMC10232760 DOI: 10.3389/fmicb.2023.1196957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 04/21/2023] [Indexed: 06/07/2023] Open
Abstract
Surface proteins of Gram-positive pathogens are key determinants of virulence that substantially shape host-microbe interactions. Specifically, these proteins mediate host invasion and pathogen transmission, drive the acquisition of heme-iron from hemoproteins, and subvert innate and adaptive immune cell responses to push bacterial survival and pathogenesis in a hostile environment. Herein, we briefly review and highlight the multi-facetted roles of cell wall-anchored proteins of multidrug-resistant Staphylococcus aureus, a common etiological agent of purulent skin and soft tissue infections as well as severe systemic diseases in humans. In particular, we focus on the functional diversity of staphylococcal surface proteins and discuss their impact on the variety of clinical manifestations of S. aureus infections. We also describe mechanistic and underlying principles of staphylococcal surface protein-mediated immune evasion and coupled strategies S. aureus utilizes to paralyze patrolling neutrophils, macrophages, and other immune cells. Ultimately, we provide a systematic overview of novel therapeutic concepts and anti-infective strategies that aim at neutralizing S. aureus surface proteins or sortases, the molecular catalysts of protein anchoring in Gram-positive bacteria.
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Affiliation(s)
- Nicoletta Schwermann
- Research Group Pathogenesis of Bacterial Infections, TWINCORE, Centre for Experimental and Clinical Infection Research, a Joint Venture Between the Hannover Medical School and the Helmholtz Centre for Infection Research, Hannover, Germany
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
| | - Volker Winstel
- Research Group Pathogenesis of Bacterial Infections, TWINCORE, Centre for Experimental and Clinical Infection Research, a Joint Venture Between the Hannover Medical School and the Helmholtz Centre for Infection Research, Hannover, Germany
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
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Yarawsky AE, Ori AL, English LR, Whitten ST, Herr AB. Convergent behavior of extended stalk regions from staphylococcal surface proteins with widely divergent sequence patterns. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.06.523059. [PMID: 36711672 PMCID: PMC9881980 DOI: 10.1101/2023.01.06.523059] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Staphylococcus epidermidis and S. aureus are highly problematic bacteria in hospital settings. This stems, at least in part, from strong abilities to form biofilms on abiotic or biotic surfaces. Biofilms are well-organized multicellular aggregates of bacteria, which, when formed on indwelling medical devices, lead to infections that are difficult to treat. Cell wall-anchored (CWA) proteins are known to be important players in biofilm formation and infection. Many of these proteins have putative stalk-like regions or regions of low complexity near the cell wall-anchoring motif. Recent work demonstrated the strong propensity of the stalk region of the S. epidermidis accumulation-associated protein (Aap) to remain highly extended under solution conditions that typically induce compaction or other significant conformational changes. This behavior is consistent with the expected function of a stalk-like region that is covalently attached to the cell wall peptidoglycan and projects the adhesive domains of Aap away from the cell surface. In this study, we evaluate whether the ability to resist compaction is a common theme among stalk regions from various staphylococcal CWA proteins. Circular dichroism spectroscopy was used to examine secondary structure changes as a function of temperature and cosolvents along with sedimentation velocity analytical ultracentrifugation and SAXS to characterize structural characteristics in solution. All stalk regions tested are intrinsically disordered, lacking secondary structure beyond random coil and polyproline type II helix, and they all sample highly extended conformations. Remarkably, the Ser-Asp dipeptide repeat region of SdrC exhibited nearly identical behavior in solution when compared to the Aap Pro/Gly-rich region, despite highly divergent sequence patterns, indicating conservation of function by various distinct staphylococcal CWA protein stalk regions.
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Affiliation(s)
- Alexander E. Yarawsky
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Andrea L. Ori
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA,Medical Sciences Baccalaureate Program, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Lance R. English
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Steven T. Whitten
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Andrew B. Herr
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA,Division of Infectious Diseases, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
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Cell-surface protein YwfG of Lactococcus lactis binds to α-1,2-linked mannose. PLoS One 2023; 18:e0273955. [PMID: 36602978 DOI: 10.1371/journal.pone.0273955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 12/06/2022] [Indexed: 01/06/2023] Open
Abstract
Lactococcus lactis strains are used as starter cultures in the production of fermented dairy and vegetable foods, but the species also occurs in other niches such as plant material. Lactococcus lactis subsp. lactis G50 (G50) is a plant-derived strain and potential candidate probiotics. Western blotting of cell-wall proteins using antibodies generated against whole G50 cells detected a 120-kDa protein. MALDI-TOF MS analysis identified it as YwfG, a Leu-Pro-any-Thr-Gly cell-wall-anchor-domain-containing protein. Based on a predicted domain structure, a recombinant YwfG variant covering the N-terminal half (aa 28-511) of YwfG (YwfG28-511) was crystallized and the crystal structure was determined. The structure consisted of an L-type lectin domain, a mucin-binding protein domain, and a mucus-binding protein repeat. Recombinant YwfG variants containing combinations of these domains (YwfG28-270, YwfG28-336, YwfG28-511, MubR4) were prepared and their interactions with monosaccharides were examined by isothermal titration calorimetry; the only interaction observed was between YwfG28-270, which contained the L-type lectin domain, and d-mannose. Among four mannobioses, α-1,2-mannobiose had the highest affinity for YwfG28-270 (dissociation constant = 34 μM). YwfG28-270 also interacted with yeast mannoproteins and yeast mannan. Soaking of the crystals of YwfG28-511 with mannose or α-1,2-mannobiose revealed that both sugars bound to the L-type lectin domain in a similar manner, although the presence of the mucin-binding protein domain and the mucus-binding protein repeat within the recombinant protein inhibited the interaction between the L-type lectin domain and mannose residues. Three of the YwfG variants (except MubR4) induced aggregation of yeast cells. Strain G50 also induced aggregation of yeast cells, which was abolished by deletion of ywfG from G50, suggesting that surface YwfG contributes to the interaction with yeast cells. These findings provide new structural and functional insights into the interaction between L. lactis and its ecological niche via binding of the cell-surface protein YwfG with mannose.
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Su X, Yu H, Wang X, Zhang C, Wang H, Kong X, Qu Y, Luan Y, Meng Y, Guan J, Song G, Wang L, Song W, Zhao Y. Cyanidin chloride protects mice from methicillin-resistant Staphylococcus aureus-induced pneumonia by targeting Sortase A. Virulence 2022; 13:1434-1445. [PMID: 35983964 PMCID: PMC9397467 DOI: 10.1080/21505594.2022.2112831] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) has been developing rapidly in recent years. It poses a severe peril to global health care, and the new strategies to against the MRSA is urgently needed. Sortase A (SrtA) regulates the anchoring of many surface proteins. Compounds repress Staphylococcus aureus (S. aureus) cysteine transpeptidase SrtA are considered adequate potent virulence inhibitors. Then, we describe the identification of an effective SrtA inhibitor, cyanidin chloride, a bioflavonoid compound isolated from various plants. It has a reversible inhibitory effect on SrtA activity at an IC50 of 21.91 μg/mL. As a SrtA inhibitor, cyanidin chloride antagonizes SrtA-related virulence phenotypes due to its breadth and specificity, including fibrinogen adhesion, A549 cell invasion, biofilm formation, and surface protein (SpA) anchoring. Subsequently, molecular docking and fluorescence quenching revealed that SrtA and cyanidin chloride had robust mutual affinity. Further mechanistic studies revealed that Arg-197, Gly-167, and Sep-116 were the key-binding sites mediating the interaction between SrtA and cyanidin chloride. Notably, a significant therapeutic effect of cyanidin chloride in vivo was also observed on the mouse pneumonia model induced by MRSA. In conclusion, our study indicates that cyanidin chloride potentially represents a new candidate SrtA inhibitor for S. aureus and potentially be developed as a new antivirulence agent.
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Affiliation(s)
- Xin Su
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Hangqian Yu
- Center for Pathogen Biology and Infectious Diseases, Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, The First Hospital of Jilin University, Changchun, China
| | - Xingye Wang
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Chi Zhang
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Heming Wang
- Department of Gastroenterology, Zhongshan Hospital of Fudan University, Shanghai, China
| | - Xiangri Kong
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China,College of Animal Science, Jilin University, Changchun, China
| | - Yishen Qu
- Endocrinology Department, Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, China
| | - Yanhe Luan
- College of Animal Science, Jilin University, Changchun, China
| | - Ying Meng
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Jiyu Guan
- Department of Anesthesiology, Peking University Third Hospital, Beijing, China
| | - Guangqi Song
- Department of Gastroenterology, Zhongshan Hospital of Fudan University, Shanghai, China
| | - Li Wang
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China,CONTACT Li Wang
| | - Wu Song
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China,Wu Song
| | - Yicheng Zhao
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China,Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China,Yicheng Zhao
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Grousd JA, Dresden BP, Riesmeyer AM, Cooper VS, Bomberger JM, Richardson AR, Alcorn JF. Novel Requirement for Staphylococcal Cell Wall-Anchored Protein SasD in Pulmonary Infection. Microbiol Spectr 2022; 10:e0164522. [PMID: 36040164 PMCID: PMC9603976 DOI: 10.1128/spectrum.01645-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 08/16/2022] [Indexed: 02/04/2023] Open
Abstract
Staphylococcus aureus can complicate preceding viral infections, including influenza virus. A bacterial infection combined with a preceding viral infection, known as superinfection, leads to worse outcomes than a single infection. Most of the pulmonary infection literature focuses on the changes in immune responses to bacteria between homeostatic and virally infected lungs. However, it is unclear how much of an influence bacterial virulence factors have in single or superinfection. Staphylococcal species express a broad range of cell wall-anchored proteins (CWAs) that have roles in host adhesion, nutrient acquisition, and immune evasion. We screened the importance of these CWAs using mutants lacking individual CWAs in vivo in both bacterial pneumonia and influenza superinfection. In bacterial pneumonia, the lack of individual CWAs leads to various decreases in bacterial burden, lung damage, and immune infiltration into the lung. However, the presence of a preceding influenza infection partially abrogates the requirement for CWAs. In the screen, we found that the uncharacterized CWA S. aureus surface protein D (SasD) induced changes in both inflammatory and homeostatic lung markers. We further characterized a SasD mutant (sasD A50.1) in the context of pneumonia. Mice infected with sasD A50.1 have decreased bacterial burden, inflammatory responses, and mortality compared to wild-type S. aureus. Mice also have reduced levels of interleukin-1β (IL-1β), likely derived from macrophages. Reductions in IL-1β transcript levels as well as increased macrophage viability point at differences in cell death pathways. These data identify a novel virulence factor for S. aureus that influences inflammatory signaling within the lung. IMPORTANCE Staphylococcus aureus is a common commensal bacterium that can cause severe infections, such as pneumonia. In the lung, viral infections increase the risk of staphylococcal pneumonia, leading to combined infections known as superinfections. The most common virus associated with S. aureus pneumonia is influenza, and superinfections lead to worse patient outcomes than either infection alone. While there is much known about how the immune system differs between healthy and virally infected lungs, the role of bacterial virulence factors in single and superinfection is less understood. The significance of our research is identifying bacterial components that play a role in the initiation of lung injury, which could lead to future therapies to prevent pulmonary single or superinfection with S. aureus.
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Affiliation(s)
- Jennifer A. Grousd
- Department of Immunology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Pediatrics, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Brooke P. Dresden
- Department of Pediatrics, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Abigail M. Riesmeyer
- Department of Pediatrics, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Vaughn S. Cooper
- Department of Microbiology & Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jennifer M. Bomberger
- Department of Microbiology & Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Anthony R. Richardson
- Department of Microbiology & Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - John F. Alcorn
- Department of Immunology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Pediatrics, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
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In silico Evaluation of Dodonic Acid from Dodonaea viscosa Jacq on Target Proteins from Staphylococcus aureus. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2022. [DOI: 10.22207/jpam.16.3.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dodonaea viscosa Jacq is known as “chamana” in the popular flora of Peru. The traditional medicine uses its leaves as ingredient in fermented beverages from Zea mays and also in external uses for anti-inflammatory diseases. The aim was to study the role of dodonic acid against several protein targets of S. aureus. This study was focused on to analyse the role of dodonic acid against S. aureus target proteins such as on Sortase-A, DNA gyrase, dihydrofolate reductase (DHFR), clumping factor, dehydrosqualene synthase, and undecaprenyl di-phosphate synthase as a promising candidate molecule. The docking analysis of dodonic acid showed the best docking score energy on S. aureus undecaprenyl diphosphate synthase with -11.2 kcal/mol and demonstrated to be a very stable molecule at physiological conditions during the molecular dynamic for 50 ns. As conclusion, the extract demonstrated to be active against S. aureus and dodonic acid might be a promising molecule acting on the S. aureus undecaprenyl diphosphate synthase.
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13
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Li J, Wen Q, Gu F, An L, Yu T. Non-antibiotic strategies for prevention and treatment of internalized Staphylococcus aureus. Front Microbiol 2022; 13:974984. [PMID: 36118198 PMCID: PMC9471010 DOI: 10.3389/fmicb.2022.974984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 08/08/2022] [Indexed: 12/01/2022] Open
Abstract
Staphylococcus aureus (S. aureus) infections are often difficult to cure completely. One of the main reasons for this difficulty is that S. aureus can be internalized into cells after infecting tissue. Because conventional antibiotics and immune cells have difficulty entering cells, the bacteria can survive long enough to cause recurrent infections, which poses a serious burden in healthcare settings because repeated infections drastically increase treatment costs. Therefore, preventing and treating S. aureus internalization is becoming a research hotspot. S. aureus internalization can essentially be divided into three phases: (1) S. aureus binds to the extracellular matrix (ECM), (2) fibronectin (Fn) receptors mediate S. aureus internalization into cells, and (3) intracellular S. aureus and persistence into cells. Different phases require different treatments. Many studies have reported on different treatments at different phases of bacterial infection. In the first and second phases, the latest research results show that the cell wall-anchored protein vaccine and some microbial agents can inhibit the adhesion of S. aureus to host cells. In the third phase, nanoparticles, photochemical internalization (PCI), cell-penetrating peptides (CPPs), antimicrobial peptides (AMPs), and bacteriophage therapy can effectively eliminate bacteria from cells. In this paper, the recent progress in the infection process and the prevention and treatment of S. aureus internalization is summarized by reviewing a large number of studies.
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Affiliation(s)
- Jiangbi Li
- Department of Orthopedics, The First Hospital of Jilin University, Changchun, China
| | - Qiangqiang Wen
- Department of Orthopedics, The Affiliated Hospital of Northwest University, Xi’an, China
| | - Feng Gu
- Department of Orthopedics, The First Hospital of Jilin University, Changchun, China
| | - Lijuan An
- Department of Rehabilitation Medicine, The Second Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Tiecheng Yu
- Department of Orthopedics, The First Hospital of Jilin University, Changchun, China
- *Correspondence: Tiecheng Yu,
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14
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Olivera-Ugarte SM, Bolduc M, Laliberté-Gagné MÈ, Blanchette LJ, Garneau C, Fillion M, Savard P, Dubuc I, Flamand L, Farnòs O, Xu X, Kamen A, Gilbert M, Rabezanahary H, Scarrone M, Couture C, Baz M, Leclerc D. A nanoparticle-based COVID-19 vaccine candidate elicits broad neutralizing antibodies and protects against SARS-CoV-2 infection. NANOMEDICINE: NANOTECHNOLOGY, BIOLOGY AND MEDICINE 2022; 44:102584. [PMID: 35850421 PMCID: PMC9287509 DOI: 10.1016/j.nano.2022.102584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/14/2022] [Accepted: 07/04/2022] [Indexed: 11/18/2022]
Abstract
A vaccine candidate to SARS-CoV-2 was constructed by coupling the viral receptor binding domain (RBD) to the surface of the papaya mosaic virus (PapMV) nanoparticle (nano) to generate the RBD-PapMV vaccine. Immunization of mice with the coupled RBD-PapMV vaccine enhanced the antibody titers and the T-cell mediated immune response directed to the RBD antigen as compared to immunization with the non-coupled vaccine formulation (RBD + PapMV nano). Anti-RBD antibodies, generated in vaccinated animals, neutralized SARS-CoV-2 infection in vitro against the ancestral, Delta and the Omicron variants. At last, immunization of mice susceptible to the infection by SARS-CoV-2 (K18-hACE2 transgenic mice) with the RBD-PapMV vaccine induced protection to the ancestral SARS-CoV-2 infectious challenge. The induction of the broad neutralization against SARS-CoV-2 variants induced by the RBD-PapMV vaccine demonstrate the potential of the PapMV vaccine platform in the development of efficient vaccines against viral respiratory infections.
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15
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Targeting the Holy Triangle of Quorum Sensing, Biofilm Formation, and Antibiotic Resistance in Pathogenic Bacteria. Microorganisms 2022; 10:microorganisms10061239. [PMID: 35744757 PMCID: PMC9228545 DOI: 10.3390/microorganisms10061239] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 12/12/2022] Open
Abstract
Chronic and recurrent bacterial infections are frequently associated with the formation of biofilms on biotic or abiotic materials that are composed of mono- or multi-species cultures of bacteria/fungi embedded in an extracellular matrix produced by the microorganisms. Biofilm formation is, among others, regulated by quorum sensing (QS) which is an interbacterial communication system usually composed of two-component systems (TCSs) of secreted autoinducer compounds that activate signal transduction pathways through interaction with their respective receptors. Embedded in the biofilms, the bacteria are protected from environmental stress stimuli, and they often show reduced responses to antibiotics, making it difficult to eradicate the bacterial infection. Besides reduced penetration of antibiotics through the intricate structure of the biofilms, the sessile biofilm-embedded bacteria show reduced metabolic activity making them intrinsically less sensitive to antibiotics. Moreover, they frequently express elevated levels of efflux pumps that extrude antibiotics, thereby reducing their intracellular levels. Some efflux pumps are involved in the secretion of QS compounds and biofilm-related materials, besides being important for removing toxic substances from the bacteria. Some efflux pump inhibitors (EPIs) have been shown to both prevent biofilm formation and sensitize the bacteria to antibiotics, suggesting a relationship between these processes. Additionally, QS inhibitors or quenchers may affect antibiotic susceptibility. Thus, targeting elements that regulate QS and biofilm formation might be a promising approach to combat antibiotic-resistant biofilm-related bacterial infections.
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16
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Berry KA, Verhoef MTA, Leonard AC, Cox G. Staphylococcus aureus adhesion to the host. Ann N Y Acad Sci 2022; 1515:75-96. [PMID: 35705378 DOI: 10.1111/nyas.14807] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Staphylococcus aureus is a pathobiont capable of colonizing and infecting most tissues within the human body, resulting in a multitude of different clinical outcomes. Adhesion of S. aureus to the host is crucial for both host colonization and the establishment of infections. Underlying the pathogen's success is a complex and diverse arsenal of adhesins. In this review, we discuss the different classes of adhesins, including a consideration of the various adhesion sites throughout the body and the clinical outcomes of each infection type. The development of therapeutics targeting the S. aureus host-pathogen interaction is a relatively understudied area. Due to the increasing global threat of antimicrobial resistance, it is crucial that innovative and alternative approaches are considered. Neutralizing virulence factors, through the development of antivirulence agents, could reduce bacterial pathogenicity and the ever-increasing burden of S. aureus infections. This review provides insight into potentially efficacious adhesion-associated targets for the development of novel decolonizing and antivirulence strategies.
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Affiliation(s)
- Kirsten A Berry
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Mackenzie T A Verhoef
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Allison C Leonard
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Georgina Cox
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
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17
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Readnour BM, Ayinuola YA, Russo BT, Liang Z, Lee SW, Ploplis VA, Fischetti VA, Castellino FJ. Evolution of Streptococcus pyogenes has maximized the efficiency of the Sortase A cleavage motif for cell wall transpeptidation. J Biol Chem 2022; 298:101940. [PMID: 35430253 PMCID: PMC9123276 DOI: 10.1016/j.jbc.2022.101940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 04/09/2022] [Accepted: 04/12/2022] [Indexed: 11/29/2022] Open
Abstract
Trafficking of M-protein (Mprt) from the cytosol of Group A Streptococcus pyogenes (GAS) occurs via Sec translocase membrane channels that associate with Sortase A (SrtA), an enzyme that catalyzes cleavage of Mprt at the proximal C-terminal [-LPST355∗GEAA-] motif and subsequent transpeptidation of the Mprt-containing product to the cell wall (CW). These steps facilitate stable exposure of the N-terminus of Mprt to the extracellular milieu where it interacts with ligands. Previously, we found that inactivation of SrtA in GAS cells eliminated Mprt CW transpeptidation but effected little reduction in its cell surface exposure, indicating that the C-terminus of Mprt retained in the cytoplasmic membrane (CM) extends its N-terminus to the cell surface. Herein, we assessed the effects of mutating the Thr355 residue in the WT SrtA consensus sequence (LPST355∗GEAA-) in a specific Mprt, PAM. In vitro, we found that synthetic peptides with mutations (LPSX355GEAA) in the SrtA cleavage site displayed slower cleavage activities with rSrtA than the WT peptide. Aromatic residues at X had the lowest activities. Nonetheless, PAM/[Y355G] still transpeptidated the CW in vivo. However, when using isolated CMs from srtA-inactivated GAS cells, rapid cleavage of PAM/[LPSY355GEAA] occurred at E357∗ but transpeptidation did not take place. These results show that another CM-resident enzyme nonproductively cleaved PAM/[LPSYGE357∗AA]. However, SrtA associated with the translocon channel in vivo cleaved and transpeptidated PAM/[LPSX355∗GEAA] variants. These CM features allow diverse cleavage site variants to covalently attach to the CW despite the presence of other potent nonproductive CM proteases.
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Affiliation(s)
- Bradley M Readnour
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana, USA; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Yetunde A Ayinuola
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana, USA
| | - Brady T Russo
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana, USA; Department of Chemistry and Biochemistry, 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
| | - Shaun W Lee
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana, USA; Department of Biological Sciences, 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; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Vincent A Fischetti
- Laboratory of Bacterial Pathogenesis and Immunology, Rockefeller University, New York, New York, USA
| | - Francis J Castellino
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana, USA; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA.
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18
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Kumar V, Murmu S, Krishnan V. Deciphering the substrate specificity of housekeeping sortase A and pilus-specific sortase C of probiotic bacterium Lactococcus lactis. Biochimie 2022; 200:140-152. [PMID: 35654243 DOI: 10.1016/j.biochi.2022.05.017] [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: 01/28/2022] [Revised: 04/25/2022] [Accepted: 05/26/2022] [Indexed: 11/02/2022]
Abstract
Several strains and species of lactic acid bacteria (LAB) are widely used in fermented foods, including dairy products and also as probiotics, because of their contribution to various health benefits in humans. Sortase enzymes decorate the bacterial cell wall with different surface proteins and pili for facilitating the interactions with host and environment for the colonization and beneficial effects. While the sortases and sortase anchored proteins from pathogens have been the prime focus of the research in the past, sortases from many non-pathogenic bacteria, including LAB strains, have attracted attention for their potential applications in vaccine delivery and other clinical interventions. Here, we report the purification and functional characterization of two sortases (housekeeping SrtA and pilus-specific SrtC) from a probiotic Lactococcus lactis. The purified sortases were found to be active against the putative LPXTG motif-based peptide substrates, albeit with differences. The in-silico analysis provides insights into the residues involved in substrate binding and specificity. Overall, this study sheds new light on the aspects of structure, substrate specificity, and function of sortases from non-pathogenic bacteria, which may have physiological ramifications as well as their applications in sortase-mediated protein bioconjugation.
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Affiliation(s)
- Vijay Kumar
- Laboratory of Structural Microbiology, Regional Centre for Biotechnology, NCR Biotech Science Cluster 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, 121001, Haryana (NCR Delhi), India
| | - Sumit Murmu
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India; Regional Centre for Biotechnology, NCR Biotech Science Cluster 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, 121001, Haryana (NCR Delhi), India
| | - Vengadesan Krishnan
- Laboratory of Structural Microbiology, Regional Centre for Biotechnology, NCR Biotech Science Cluster 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, 121001, Haryana (NCR Delhi), India.
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19
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Scutellarin potentiates vancomycin against lethal pneumonia caused by methicillin-resistant Staphylococcus aureus through dual inhibition of sortase A and caseinolytic peptidase P. Biochem Pharmacol 2022; 199:114982. [PMID: 35247333 DOI: 10.1016/j.bcp.2022.114982] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/12/2022] [Accepted: 02/22/2022] [Indexed: 01/09/2023]
Abstract
The strategy of targeting virulence factor has received great attention as it barely develops bacterial resistance. Sortase A (SrtA) and caseinolytic peptidase P (ClpP), as important virulence factors, are considered to be ideal pharmacological targets for methicillin-resistant Staphylococcus aureus (MRSA) infection. Through screening hundreds of compounds, we found scutellarin, a natural flavonoid, markedly inhibited SrtA and ClpP activities of MRSA strain USA300 with an IC50 of 53.64 μg/mL and 107.00 μg/mL, respectively. Subsequently, we observed that scutellarin could inhibit the SrtA-related virulence of MRSA. To demonstrate whether scutellarin directly binding to SrtA, fluorescence quenching assay and molecular docking were performed and the results indicated that scutellarin directly bonded to SrtA molecule with a KA value of 7.58 × 104 L/mol. In addition to direct SrtA inhibition, scutellarin could also inhibit hemolytic activity of S. aureus by inhibiting the expression of Hla in a SrtA-independent manner. Further assays confirmed that scutellarin inhibited hemolysis by inhibiting ClpP. The combination of scutellarin and vancomycin showed enhancing inhibition of USA300 in vitro and in vivo, evidenced by decreased MIC from 3 μg/mL to 0.5 μg/mL and increased survival and improvement of lung pathology in pneumonia mice. Taken together, these results suggest that scutellarin exhibited di-inhibitory effects on SrtA and ClpP of USA300. The di-inhibition of virulence factors by scutellarin combined with vancomycin to prevent MRSA invasion of A549 cells and pneumonia in mice, indicating that scutellarin is expected to be a potential adjuvant against MRSA in the future.
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20
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Meyers S, Crescente M, Verhamme P, Martinod K. Staphylococcus aureus and Neutrophil Extracellular Traps: The Master Manipulator Meets Its Match in Immunothrombosis. Arterioscler Thromb Vasc Biol 2022; 42:261-276. [PMID: 35109674 PMCID: PMC8860219 DOI: 10.1161/atvbaha.121.316930] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Over the past 10 years, neutrophil extracellular traps (NETs) have become widely accepted as an integral player in immunothrombosis, due to their complex interplay with both pathogens and components of the coagulation system. While the release of NETs is an attempt by neutrophils to trap pathogens and constrain infections, NETs can have bystander effects on the host by inducing uncontrolled thrombosis, inflammation, and tissue damage. From an evolutionary perspective, pathogens have adapted to bypass the host innate immune response. Staphylococcus aureus (S. aureus), in particular, proficiently overcomes NET formation using several virulence factors. Here we review mechanisms of NET formation and how these are intertwined with platelet activation, the release of endothelial von Willebrand factor, and the activation of the coagulation system. We discuss the unique ability of S. aureus to modulate NET formation and alter released NETs, which helps S. aureus to escape from the host's defense mechanisms. We then discuss how platelets and the coagulation system could play a role in NET formation in S. aureus-induced infective endocarditis, and we explain how targeting these complex cellular interactions could reveal novel therapies to treat this disease and other immunothrombotic disorders.
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Affiliation(s)
- Severien Meyers
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Belgium (S.M., M.C., P.V., K.M.)
| | - Marilena Crescente
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Belgium (S.M., M.C., P.V., K.M.).,Department of Life Sciences, Manchester Metropolitan University, United Kingdom (M.C.)
| | - Peter Verhamme
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Belgium (S.M., M.C., P.V., K.M.)
| | - Kimberly Martinod
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Belgium (S.M., M.C., P.V., K.M.)
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21
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Barthels F, Meyr J, Hammerschmidt SJ, Marciniak T, Räder HJ, Ziebuhr W, Engels B, Schirmeister T. 2-Sulfonylpyrimidines as Privileged Warheads for the Development of S. aureus Sortase A Inhibitors. Front Mol Biosci 2022; 8:804970. [PMID: 35047562 PMCID: PMC8763382 DOI: 10.3389/fmolb.2021.804970] [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: 10/29/2021] [Accepted: 12/03/2021] [Indexed: 11/29/2022] Open
Abstract
Staphylococcus aureus is one of the most frequent causes of nosocomial and community-acquired infections, with emerging multiresistant isolates causing a significant burden to public health systems. We identified 2-sulfonylpyrimidines as a new class of potent inhibitors against S. aureus sortase A acting by covalent modification of the active site cysteine 184. Series of derivatives were synthesized to derive structure-activity relationship (SAR) with the most potent compounds displaying low micromolar KI values. Studies on the inhibition selectivity of homologous cysteine proteases showed that 2-sulfonylpyrimidines reacted efficiently with protonated cysteine residues as found in sortase A, though surprisingly, no reaction occurred with the more nucleophilic cysteine residue from imidazolinium-thiolate dyads of cathepsin-like proteases. By means of enzymatic and chemical kinetics as well as quantum chemical calculations, it could be rationalized that the SNAr reaction between protonated cysteine residues and 2-sulfonylpyrimidines proceeds in a concerted fashion, and the mechanism involves a ternary transition state with a conjugated base. Molecular docking and enzyme inhibition at variable pH values allowed us to hypothesize that in sortase A this base is represented by the catalytic histidine 120, which could be substantiated by QM model calculation with 4-methylimidazole as histidine analog.
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Affiliation(s)
- Fabian Barthels
- Institute for Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University, Mainz, Germany
| | - Jessica Meyr
- Institute of Physical and Theoretical Chemistry, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Stefan J Hammerschmidt
- Institute for Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University, Mainz, Germany
| | - Tessa Marciniak
- Institute for Molecular Infection Biology, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | | | - Wilma Ziebuhr
- Institute for Molecular Infection Biology, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Bernd Engels
- Institute of Physical and Theoretical Chemistry, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Tanja Schirmeister
- Institute for Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University, Mainz, Germany
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22
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Vazquez DS, Schilbert HM, Dodero VI. Molecular and Structural Parallels between Gluten Pathogenic Peptides and Bacterial-Derived Proteins by Bioinformatics Analysis. Int J Mol Sci 2021; 22:9278. [PMID: 34502187 PMCID: PMC8430993 DOI: 10.3390/ijms22179278] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 02/08/2023] Open
Abstract
Gluten-related disorders (GRDs) are a group of diseases that involve the activation of the immune system triggered by the ingestion of gluten, with a worldwide prevalence of 5%. Among them, Celiac disease (CeD) is a T-cell-mediated autoimmune disease causing a plethora of symptoms from diarrhea and malabsorption to lymphoma. Even though GRDs have been intensively studied, the environmental triggers promoting the diverse reactions to gluten proteins in susceptible individuals remain elusive. It has been proposed that pathogens could act as disease-causing environmental triggers of CeD by molecular mimicry mechanisms. Additionally, it could also be possible that unrecognized molecular, structural, and physical parallels between gluten and pathogens have a relevant role. Herein, we report sequence, structural and physical similarities of the two most relevant gluten peptides, the 33-mer and p31-43 gliadin peptides, with bacterial pathogens using bioinformatics going beyond the molecular mimicry hypothesis. First, a stringent BLASTp search using the two gliadin peptides identified high sequence similarity regions within pathogen-derived proteins, e.g., extracellular proteins from Streptococcus pneumoniae and Granulicatella sp. Second, molecular dynamics calculations of an updated α-2-gliadin model revealed close spatial localization and solvent-exposure of the 33-mer and p31-43 peptide, which was compared with the pathogen-related proteins by homology models and localization predictors. We found putative functions of the identified pathogen-derived sequence by identifying T-cell epitopes and SH3/WW-binding domains. Finally, shape and size parallels between the pathogens and the superstructures of gliadin peptides gave rise to novel hypotheses about activation of innate immunity and dysbiosis. Based on our structural findings and the similarities with the bacterial pathogens, evidence emerges that these pathologically relevant gluten-derived peptides could behave as non-replicating pathogens opening new research questions in the interface of innate immunity, microbiome, and food research.
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Affiliation(s)
- Diego S. Vazquez
- Grupo de Biología Estructural y Biotecnología (GBEyB-IMBICE), Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Sáenz Peña 352, Bernal B1876BXD, Buenos Aires, Argentina;
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, Ciudad Autónoma C1033AAJ, Buenos Aires, Argentina
| | - Hanna M. Schilbert
- Department of Chemistry, Organic Chemistry OCIII, Universität Bielefeld, Universitätsstraße 25, 33615 Bielefeld, Germany;
| | - Veronica I. Dodero
- Department of Chemistry, Organic Chemistry OCIII, Universität Bielefeld, Universitätsstraße 25, 33615 Bielefeld, Germany;
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23
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Coutinho TDNP, Barroso FDD, da Silva CR, da Silva AR, Cabral VPDF, Sá LGDAV, Cândido TM, da Silva LJ, Ferreira TL, da Silva WMB, Silva J, Marinho ES, Cavalcanti BC, Moraes MO, Nobre Júnior H, Andrade Neto JBD. EFFECTS OF KETAMINE IN METHICILLIN RESISTANT S. aureus AND IN SILICO INTERACTION WITH SORTASE A. Can J Microbiol 2021; 67:885-893. [PMID: 34314621 DOI: 10.1139/cjm-2021-0093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main human pathogens and is responsible for many diseases ranging from skin infections to more invasive infections. These infections are dangerous and expensive to treat because these strains are resistant to a large number of conventional antibiotics. Having said that, Antibacterial effect of ketamine against MRSA strains, its mechanism of action and in silico interaction with sortase A was evaluated. The antibacterial effect of ketamine was assessed by the broth microdilution method. Subsequently, the mechanism of action was assessed using flow cytometry and molecular docking assays with sortase A. Our results showed that Ketamine has a significant antibacterial activity against MRSA strains in the range of 2.49 to 3.73 mM. Their mechanism of action involves alterations in the membrane integrity and DNA damage, reducing cell viability that provoke death by apoptosis. In addition, Ketamine compound had affinity for S. aureus sortase A. These results indicate that this compound can be an alternative to develop new strategies to combat of infections caused by MRSA.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Jacilene Silva
- State University of Ceara, 67843, Fortaleza, CE, Brazil;
| | | | | | | | - Hélio Nobre Júnior
- Federal University of Ceará, Department of Clinical and Toxicological Analysis, Rua Capitão Francisco Pedro, 1210 - Rodolfo Teófilo, Fortaleza, Brazil, 60430-370;
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24
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Wang L, Wang G, Qu H, Wang K, Jing S, Guan S, Su L, Li Q, Wang D. Taxifolin, an Inhibitor of Sortase A, Interferes With the Adhesion of Methicillin-Resistant Staphylococcal aureus. Front Microbiol 2021; 12:686864. [PMID: 34295320 PMCID: PMC8290497 DOI: 10.3389/fmicb.2021.686864] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 06/14/2021] [Indexed: 11/30/2022] Open
Abstract
The evolution and spread of methicillin-resistant Staphylococcus aureus (MRSA) poses a significant hidden risk to human public health. The majority of antibiotics used clinically have become mostly ineffective, and so the development of novel anti-infection strategies is urgently required. Since Staphylococcus aureus (S. aureus) cysteine transpeptidase sortase A (SrtA) mediates the surface-anchoring of proteins to its surface, compounds that inhibit SrtA are considered potential antivirulence treatments. Herein, we report on the efficacy of the potent SrtA inhibitor taxifolin (Tax), a flavonoid compound isolated from Chinese herbs. It was able to reversibly block the activity of SrtA with an IC50 of 24.53 ± 0.42 μM. Tax did not display toxicity toward mammalian cells or S. aureus at a concentration of 200 μM. In addition, Tax attenuated the virulence-related phenotype of SrtA in vitro by decreasing the adherence of S. aureus, reducing the formation of a biofilm, and anchoring of S. aureus protein A on its cell wall. The mechanism of the SrtA-Tax interaction was determined using a localized surface plasmon resonance assay. Subsequent mechanistic studies confirmed that Asp-170 and Gln-172 were the principal sites on SrtA with which it binds to Tax. Importantly, in vivo experiments demonstrated that Tax protects mice against pneumonia induced by lethal doses of MRSA, significantly improving their survival rate and reducing the number of viable S. aureus in the lung tissue. The present study indicates that Tax is a useful pioneer compound for the development of novel agents against S. aureus infections.
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Affiliation(s)
- Li Wang
- College of Animal Science, Jilin University, Changchun, China
| | - Guangming Wang
- Department of Neurosurgery, The First Hospital of Jilin University, Changchun, China
| | - Han Qu
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Kai Wang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Shisong Jing
- College of Animal Science, Jilin University, Changchun, China
| | - Shuhan Guan
- College of Animal Science, Jilin University, Changchun, China
| | - Liyan Su
- College of Veterinary Medicine, Jilin University, Changchun, China
| | - Qianxue Li
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Dacheng Wang
- College of Animal Science, Jilin University, Changchun, China
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Shi M, Chen X, Sun Y, Kim HK, Schneewind O, Missiakas D. A protein A based Staphylococcus aureus vaccine with improved safety. Vaccine 2021; 39:3907-3915. [PMID: 34088508 DOI: 10.1016/j.vaccine.2021.05.072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 04/29/2021] [Accepted: 05/23/2021] [Indexed: 11/30/2022]
Abstract
Exposure to Staphylococcus aureus does not lead to immunity as evidenced by the persistent colonization of one third of the human population. S. aureus immune escape is mediated by factors that preempt complement activation, destroy phagocytes, and modify B and T cell responses. One such factor, Staphylococcal protein A (SpA) encompasses five Immunoglobulin binding domains (IgBDs) that associate with the Fcγ domain to block phagocytosis. IgBDs also associate with Fab encoded by VH3 clan related genes. SpA binding to VH3-IgM that serves as a B cell receptor results in B cell expansion and secretion of antibodies with no specificity for S. aureus. SpA crosslinking of VH3-IgG and VH3-IgE bound to cognate receptors of mast cells and basophils promotes histamine release and anaphylaxis. Earlier work developed a prototype variant SpAKKAA with four amino acid substitutions in each IgBD. When tested in animal models, SpAKKAA elicited neutralizing antibodies and protection against infection. We show here that SpAKKAA retains crosslinking activity for VH3-IgG and VH3-IgE. We use a rational approach to design and test 67 new SpA variants for loss of VH3 binding and anaphylactic activities. We identify two detoxified candidates that elicit SpA-neutralizing antibodies and protect animals from S. aureus colonization and bloodstream infection. The new detoxified SpA candidates bear three instead of four amino acid substitutions thus increasing the development of SpA-specific antibodies. We propose that detoxified SpA variants unable to crosslink VH3-idiotypic immunoglobulin may be suitably developed as clinical-grade vaccines for safety and efficacy testing in humans.
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Affiliation(s)
- Miaomiao Shi
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, IL 60439, United States
| | - Xinhai Chen
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, IL 60439, United States
| | - Yan Sun
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, IL 60439, United States
| | - Hwan Keun Kim
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, IL 60439, United States
| | - Olaf Schneewind
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, IL 60439, United States
| | - Dominique Missiakas
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, IL 60439, United States.
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Scaffidi SJ, Shebes MA, Yu W. Tracking the Subcellular Localization of Surface Proteins in Staphylococcus aureus by Immunofluorescence Microscopy. Bio Protoc 2021; 11:e4038. [PMID: 34150940 DOI: 10.21769/bioprotoc.4038] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/03/2021] [Accepted: 04/27/2021] [Indexed: 11/02/2022] Open
Abstract
Surface proteins of Staphylococcus aureus and other Gram-positive bacteria play essential roles in bacterial colonization and host-microbe interactions. Surface protein precursors containing a YSIRK/GXXS signal peptide are translocated across the septal membrane at mid-cell, anchored to the cell wall peptidoglycan at the cross-wall compartment, and presented on the new hemispheres of the daughter cells following cell division. After several generations of cell division, these surface proteins will eventually cover the entire cell surface. To understand how these proteins travel from the bacterial cytoplasm to the cell surface, we describe a series of immunofluorescence microscopy protocols designed to detect the stepwise subcellular localization of the surface protein precursors: surface display (protocol A), cross-wall localization (protocol B), and cytoplasmic/septal membrane localization (protocol C). Staphylococcal protein A (SpA) is the model protein used in this work. The protocols described here are readily adapted to study the localization of other surface proteins as well as other cytoplasmic or membrane proteins in S. aureus in general. Furthermore, the protocols can be modified and adapted for use in other Gram-positive bacteria. Graphic abstract: Tracking the subcellular localization of surface proteins in S. aureus.
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Affiliation(s)
- Salvatore J Scaffidi
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, USA
| | - Mac A Shebes
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, USA
| | - Wenqi Yu
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, USA
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27
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Staphylococcal Infections: Host and Pathogenic Factors. Microorganisms 2021; 9:microorganisms9051080. [PMID: 34069873 PMCID: PMC8157358 DOI: 10.3390/microorganisms9051080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 12/12/2022] Open
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Abstract
Gram-negative bacteria have a unique cell envelope with a lipopolysaccharide-containing outer membrane that is tightly connected to a thin layer of peptidoglycan. The tight connection between the outer membrane and peptidoglycan is needed to maintain the outer membrane as an impermeable barrier for many toxic molecules and antibiotics. Enterobacteriaceae such as Escherichia coli covalently attach the abundant outer membrane-anchored lipoprotein Lpp (Braun’s lipoprotein) to tripeptides in peptidoglycan, mediated by the transpeptidases LdtA, LdtB, and LdtC. LdtD and LdtE are members of the same family of ld-transpeptidases but they catalyze a different reaction, the formation of 3-3 cross-links in the peptidoglycan. The function of the sixth homologue in E. coli, LdtF, remains unclear, although it has been shown to become essential in cells with inhibited lipopolysaccharide export to the outer membrane. We now show that LdtF hydrolyzes the Lpp-peptidoglycan linkage, detaching Lpp from peptidoglycan, and have renamed LdtF to peptidoglycan meso-diaminopimelic acid protein amidase A (DpaA). We show that the detachment of Lpp from peptidoglycan is beneficial for the cell under certain stress conditions and that the deletion of dpaA allows frequent transposon inactivation in the lapB (yciM) gene, whose product downregulates lipopolysaccharide biosynthesis. DpaA-like proteins have characteristic sequence motifs and are present in many Gram-negative bacteria, of which some have no Lpp, raising the possibility that DpaA has other substrates in these species. Overall, our data show that the Lpp-peptidoglycan linkage in E. coli is more dynamic than previously appreciated.
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Zhang R, Shebes MA, Kho K, Scaffidi SJ, Meredith TC, Yu W. Spatial regulation of protein A in Staphylococcus aureus. Mol Microbiol 2021; 116:589-605. [PMID: 33949015 DOI: 10.1111/mmi.14734] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/29/2021] [Accepted: 04/30/2021] [Indexed: 12/31/2022]
Abstract
Surface proteins of Staphylococcus aureus play vital roles in bacterial physiology and pathogenesis. Recent work suggests that surface proteins are spatially regulated by a YSIRK/GXXS signal peptide that promotes cross-wall targeting at the mid-cell, though the mechanisms remain unclear. We previously showed that protein A (SpA), a YSIRK/GXXS protein and key staphylococcal virulence factor, mis-localizes in a ltaS mutant deficient in lipoteichoic acid (LTA) production. Here, we identified that SpA contains another cross-wall targeting signal, the LysM domain, which, in addition to the YSIRK/GXXS signal peptide, significantly enhances SpA cross-wall targeting. We show that LTA synthesis, but not LtaS, is required for SpA septal anchoring and cross-wall deposition. Interestingly, LTA is predominantly found at the peripheral cell membrane and is diminished at the septum of dividing staphylococcal cells, suggesting a restriction mechanism for SpA septal localization. Finally, we show that D-alanylation of LTA abolishes SpA cross-wall deposition by disrupting SpA distribution in the peptidoglycan layer without altering SpA septal anchoring. Our study reveals that multiple factors contribute to the spatial regulation and cross-wall targeting of SpA via different mechanisms, which coordinately ensures efficient incorporation of surface proteins into the growing peptidoglycan during the cell cycle.
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Affiliation(s)
- Ran Zhang
- Department of Cell Biology, Microbiology and Molecular Biology (CMMB), University of South Florida, Tampa, FL, USA
| | - Mac A Shebes
- Department of Cell Biology, Microbiology and Molecular Biology (CMMB), University of South Florida, Tampa, FL, USA
| | - Kelvin Kho
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Salvatore J Scaffidi
- Department of Cell Biology, Microbiology and Molecular Biology (CMMB), University of South Florida, Tampa, FL, USA
| | - Timothy C Meredith
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Wenqi Yu
- Department of Cell Biology, Microbiology and Molecular Biology (CMMB), University of South Florida, Tampa, FL, USA
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Wójcik-Bojek U, Rywaniak J, Bernat P, Podsędek A, Kajszczak D, Sadowska B. An In Vitro Study of the Effect of Viburnum opulus Extracts on Key Processes in the Development of Staphylococcal Infections. Molecules 2021; 26:molecules26061758. [PMID: 33801012 PMCID: PMC8003844 DOI: 10.3390/molecules26061758] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 01/21/2023] Open
Abstract
Staphylococcus aureus is still one of the leading causes of both hospital- and community-acquired infections. Due to the very high percentage of drug-resistant strains, the participation of drug-tolerant biofilms in pathological changes, and thus the limited number of effective antibiotics, there is an urgent need to search for alternative methods of prevention or treatment for S. aureus infections. In the present study, biochemically characterized (HPLC/UPLC–QTOF–MS) acetonic, ethanolic, and water extracts from fruits and bark of Viburnum opulus L. were tested in vitro as diet additives that potentially prevent staphylococcal infections. The impacts of V. opulus extracts on sortase A (SrtA) activity (Fluorimetric Assay), staphylococcal protein A (SpA) expression (FITC-labelled specific antibodies), the lipid composition of bacterial cell membranes (LC-MS/MS, GC/MS), and biofilm formation (LIVE/DEAD BacLight) were assessed. The cytotoxicity of V. opulus extracts to the human fibroblast line HFF-1 was also tested (MTT reduction). V. opulus extracts strongly inhibited SrtA activity and SpA expression, caused modifications of S. aureus cell membrane, limited biofilm formation by staphylococci, and were non-cytotoxic. Therefore, they have pro-health potential. Nevertheless, their usefulness as diet supplements that are beneficial for the prevention of staphylococcal infections should be confirmed in animal models in the future.
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Affiliation(s)
- Urszula Wójcik-Bojek
- Department of Immunology and Infectious Biology, Institute of Microbiology, Biotechnology and Immunology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland; (U.W.-B.); (J.R.)
| | - Joanna Rywaniak
- Department of Immunology and Infectious Biology, Institute of Microbiology, Biotechnology and Immunology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland; (U.W.-B.); (J.R.)
| | - Przemysław Bernat
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, Institute of Microbiology, Biotechnology and Immunology, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland;
| | - Anna Podsędek
- Faculty of Biotechnology and Food Sciences, Institute of Molecular and Industrial Biotechnology, Lodz University of Technology, Stefanowskiego 4/10, 90-924 Lodz, Poland; (A.P.); (D.K.)
| | - Dominika Kajszczak
- Faculty of Biotechnology and Food Sciences, Institute of Molecular and Industrial Biotechnology, Lodz University of Technology, Stefanowskiego 4/10, 90-924 Lodz, Poland; (A.P.); (D.K.)
| | - Beata Sadowska
- Department of Immunology and Infectious Biology, Institute of Microbiology, Biotechnology and Immunology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland; (U.W.-B.); (J.R.)
- Correspondence: ; Tel.: +48-42-635-45-25
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Modulation of Antigen Display on PapMV Nanoparticles Influences Its Immunogenicity. Vaccines (Basel) 2021; 9:vaccines9010033. [PMID: 33435570 PMCID: PMC7829862 DOI: 10.3390/vaccines9010033] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/02/2021] [Accepted: 01/04/2021] [Indexed: 12/13/2022] Open
Abstract
Background: The papaya mosaic virus (PapMV) vaccine platform is a rod-shaped nanoparticle made of the recombinant PapMV coat protein (CP) self-assembled around a noncoding single-stranded RNA (ssRNA) template. The PapMV nanoparticle induces innate immunity through stimulation of the Toll-like receptors (TLR) 7 and 8. The display of the vaccine antigen at the surface of the nanoparticle, associated with the co-stimulation signal via TLR7/8, ensures a strong stimulation of the immune response, which is ideal for the development of candidate vaccines. In this study, we assess the impact of where the peptide antigen is fused, whether at the surface or at the extremities of the nanoparticles, on the immune response directed to that antigen. Methods: Two different peptides from influenza A virus were used as model antigens. The conserved M2e peptide, derived from the matrix protein 2 was chosen as the B-cell epitope, and a peptide derived from the nucleocapsid was chosen as the cytotoxic T lymphocytes (CTL) epitope. These peptides were coupled at two different positions on the PapMV CP, the N- (PapMV-N) or the C-terminus (PapMV-C), using the transpeptidase activity of Sortase A (SrtA). The immune responses, both humoral and CD8+ T-cell-mediated, directed to the peptide antigens in the two different fusion contexts were analyzed and compared. The impact of coupling density at the surface of the nanoparticle was also investigated. Conclusions: The results demonstrate that coupling of the peptide antigens at the N-terminus (PapMV-N) of the PapMV CP led to an enhanced immune response to the coupled peptide antigens as compared to coupling to the C-terminus. The difference between the two vaccine platforms is linked to the enhanced capacity of the PapMV-N vaccine platform to stimulate TLR7/8. We also demonstrated that the strength of the immune response increases with the density of coupling at the surface of the nanoparticles.
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Song B, Wang J, Yan Z, Liu Z, Pan X, Zhang Y, Zhang X. Microfluidics for the rapid detection of Staphylococcus aureus using antibody-coated microspheres. Bioengineered 2020; 11:1137-1145. [PMID: 33070676 PMCID: PMC8291883 DOI: 10.1080/21655979.2020.1831362] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Staphylococcus aureus is a common foodborne pathogenic microorganism which can cause food poisoning and it is pathogenic to both humans and animals. Therefore, rapid detection of S. aureus infection is of great significance. In this study, a microfluidic platform was introduced to detect S. aureus by fluorescence labeling method and a self-made microfluidic chip, which has immune spheres were used to study the effect of capturing S. aureus. Through this experiment, we found that the platform can be used for microbial culture, and S. aureus antibody coated on the diameter of 50 ~ 90 μm microspheres for detection. On the premise of optimizing the sample flow rate and detection time, the bacterial detection was quantitatively monitored. Results showed that our platform can detect S. aureus at injection rate of 5 μL·min−1 reacted for 4 min and the detection limit of bacteria is 1.5 × 101 CFU/μL. However, the detection time of traditional method is 24 hs to 72 hs, and the operation is complex and cumbersome. These findings indicated that the microfluidic chip in this study is portable, sensitive, and accurate, laying a good foundation for further research on the application of rapid bacterial detection platform.
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Affiliation(s)
- Bo Song
- Department of Clinical Pathogen Biology, Medical Technology College, Qiqihar Medical University , Qiqihar, Heilongjiang, China
| | - Junsheng Wang
- Department of Information Science and Technology, Dalian Maritime University , Dalian, Liaoning, China
| | - Zhijun Yan
- Department of Information Science and Technology, Dalian Maritime University , Dalian, Liaoning, China
| | - Zhijian Liu
- Department of Information Science and Technology, Dalian Maritime University , Dalian, Liaoning, China
| | - Xinxiang Pan
- Maritime College, Guangdong Ocean University , Zhanjiang, China
| | - Yingbo Zhang
- Department of Clinical Pathogen Biology, Medical Technology College, Qiqihar Medical University , Qiqihar, Heilongjiang, China
| | - Xiaojie Zhang
- Department of Clinical Pathogen Biology, Medical Technology College, Qiqihar Medical University , Qiqihar, Heilongjiang, China
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Development of a Prototype Lateral Flow Immunoassay for Rapid Detection of Staphylococcal Protein A in Positive Blood Culture Samples. Diagnostics (Basel) 2020; 10:diagnostics10100794. [PMID: 33036348 PMCID: PMC7601020 DOI: 10.3390/diagnostics10100794] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/14/2020] [Accepted: 09/21/2020] [Indexed: 12/22/2022] Open
Abstract
Bloodstream infection (BSI) is a major cause of mortality in hospitalized patients worldwide. Staphylococcus aureus is one of the most common pathogens found in BSI. The conventional workflow is time consuming. Therefore, we developed a lateral flow immunoassay (LFIA) for rapid detection of S. aureus-protein A in positive blood culture samples. A total of 90 clinical isolates including 58 S. aureus and 32 non-S. aureus were spiked in simulated blood samples. The antigens were extracted by a simple boiling method and diluted before being tested using the developed LFIA strips. The results were readable by naked eye within 15 min. The sensitivity of the developed LFIA was 87.9% (51/58) and the specificity was 93.8% (30/32). When bacterial colonies were used in the test, the LFIA provided higher sensitivity and specificity (94.8% and 100%, respectively). The detection limit of the LFIA was 107 CFU/mL. Initial evaluation of the LFIA in 20 positive blood culture bottles from hospitals showed 95% agreement with the routine methods. The LFIA is a rapid, simple and highly sensitive method. No sophisticated equipment is required. It has potential for routine detection particularly in low resource settings, contributing an early diagnosis that facilitates effective treatment and reduces disease progression.
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Wen Q, Gu F, Sui Z, Su Z, Yu T. The Process of Osteoblastic Infection by Staphylococcus Aureus. Int J Med Sci 2020; 17:1327-1332. [PMID: 32624688 PMCID: PMC7330672 DOI: 10.7150/ijms.45960] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 05/18/2020] [Indexed: 12/22/2022] Open
Abstract
Bone infection is difficult to cure, and relapse frequently occurs, which is a major treatment problem. One of the main reasons for the refractory and recurrent nature of bone infection is that bacteria, such as Staphylococcus aureus (S. aureus), can be internalized into osteoblasts after infecting bone tissue, thereby avoiding attack by the immune system and antibiotics. Understanding how bacteria (such as S. aureus) are internalized into osteoblasts is key to effective treatment. S. aureus is the most common pathogenic bacterium that causes bone infection. This paper reviews the literature, analyzes the specific process of osteoblastic S. aureus infection, and summarizes specific treatment strategies to improve bone infection treatment.
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Affiliation(s)
- Qiangqiang Wen
- Department of Orthopedics, First Hospital of Jilin University, Changchun 130021, Jilin, China
| | - Feng Gu
- Department of Orthopedics, First Hospital of Jilin University, Changchun 130021, Jilin, China
| | - Zhenjiang Sui
- Department of Orthopedics, First Hospital of Jilin University, Changchun 130021, Jilin, China
| | - Zilong Su
- Department of Orthopedics, First Hospital of Jilin University, Changchun 130021, Jilin, China
| | - Tiecheng Yu
- Department of Orthopedics, First Hospital of Jilin University, Changchun 130021, Jilin, China
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Proteases as Secreted Exoproteins in Mycoplasmas from Ruminant Lungs and Their Impact on Surface-Exposed Proteins. Appl Environ Microbiol 2019; 85:AEM.01439-19. [PMID: 31540994 DOI: 10.1128/aem.01439-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 09/10/2019] [Indexed: 12/29/2022] Open
Abstract
Many mycoplasma species are isolated from the ruminant lungs as either saprophytes or true pathogens. These wall-less bacteria possess a minimal genome and reduced metabolic capabilities. Accordingly, they rely heavily on their hosts for the supply of essential metabolites and, notably, peptides. Seven of 13 ruminant lung-associated Mycoplasma (sub)species were shown to possess caseinolytic activity when grown in rich media and assessed with a quantitative fluorescence test. For some species, this activity was detected in spent medium, an indication that proteases were secreted outside the mycoplasma cells. To identify these proteases, we incubated concentrated washed cell pellets in a defined medium and analyzed the supernatants by tandem mass spectrometry. Secreted-protease activity was detected mostly in the species belonging to the Mycoplasma mycoides cluster (MMC) and, to a lesser extent, in Mycoplasma bovirhinis Analyzing a Mycoplasma mycoides subsp. capri strain, chosen as a model, we identified 35 expressed proteases among 55 predicted coding genes, of which 5 were preferentially found in the supernatant. Serine protease S41, acquired by horizontal gene transfer, was responsible for the caseinolytic activity, as demonstrated by zymography and mutant analysis. In an M. capricolum mutant, inactivation of the S41 protease resulted in marked modification of the expression or secretion of 17 predicted surface-exposed proteins. This is an indication that the S41 protease could have a role in posttranslational cleavage of surface-exposed proteins and ectodomain shedding, whose physiological impacts still need to be explored.IMPORTANCE Few studies pertaining to proteases in ruminant mycoplasmas have been reported. Here, we focus on proteases that are secreted outside the mycoplasma cell using a mass spectrometry approach. The most striking result is the identification, within the Mycoplasma mycoides cluster, of a serine protease that is exclusively detected outside the mycoplasma cells and is responsible for casein digestion. This protease may also be involved in the posttranslational processing of surface proteins, as suggested by analysis of mutants showing a marked reduction in the secretion of extracellular proteins. By analogy, this finding may help increase understanding of the mechanisms underlying this ectodomain shedding in other mycoplasma species. The gene encoding this protease is likely to have been acquired via horizontal gene transfer from Gram-positive bacteria and sortase-associated surface proteases. Whether this protease and the associated ectodomain shedding are related to virulence has yet to be ascertained.
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