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Uneme M, Ishikawa K, Furuta K, Yamashita A, Kaito C. Overexpression of the flagellar motor protein MotB sensitizes Bacillus subtilis to aminoglycosides in a motility-independent manner. PLoS One 2024; 19:e0300634. [PMID: 38669243 PMCID: PMC11051680 DOI: 10.1371/journal.pone.0300634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 03/02/2024] [Indexed: 04/28/2024] Open
Abstract
The flagellar motor proteins, MotA and MotB, form a complex that rotates the flagella by utilizing the proton motive force (PMF) at the bacterial cell membrane. Although PMF affects the susceptibility to aminoglycosides, the effect of flagellar motor proteins on the susceptibility to aminoglycosides has not been investigated. Here, we found that MotB overexpression increased susceptibility to aminoglycosides, such as kanamycin and gentamicin, in Bacillus subtilis without affecting swimming motility. MotB overexpression did not affect susceptibility to ribosome-targeting antibiotics other than aminoglycosides, cell wall-targeting antibiotics, DNA synthesis-inhibiting antibiotics, or antibiotics inhibiting RNA synthesis. Meanwhile, MotB overexpression increased the susceptibility to aminoglycosides even in the motA-deletion mutant, which lacks swimming motility. Overexpression of the MotB mutant protein carrying an amino acid substitution at the proton-binding site (D24A) resulted in the loss of the enhanced aminoglycoside-sensitive phenotype. These results suggested that MotB overexpression sensitizes B. subtilis to aminoglycosides in a motility-independent manner. Notably, the aminoglycoside-sensitive phenotype induced by MotB requires the proton-binding site but not the MotA/MotB complex formation.
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Affiliation(s)
- Mio Uneme
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Kazuya Ishikawa
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Kazuyuki Furuta
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Atsuko Yamashita
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Chikara Kaito
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
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2
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Zhang G, Zhang N, Xu J, Yang T, Yin H, Cai Y. Efficacy and safety of vancomycin for the treatment of Staphylococcus aureus bacteraemia: a systematic review and meta-analysis. Int J Antimicrob Agents 2023; 62:106946. [PMID: 37543121 DOI: 10.1016/j.ijantimicag.2023.106946] [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: 08/31/2022] [Revised: 06/11/2023] [Accepted: 08/01/2023] [Indexed: 08/07/2023]
Abstract
OBJECTIVES To evaluate the safety and efficacy of vancomycin with the other anti-Gram-positive bacteria antibiotics in the treatment of Staphylococcus aureus bacteraemia. METHODS We searched the PubMed, MEDLINE, Embase and Cochrane Library databases until August 2022 for studies that compared vancomycin with other antibiotic regimens for treating Staphylococcus aureus bacteraemia. Clinical and microbiological responses, adverse events, relapse rate and mortality were considered. RESULTS Fifteen randomized controlled trials and nine retrospective studies were included. The efficacy and safety data of vancomycin differed from those of the comparators group. After subgroup analysis, the differences came mainly from the trials compared with daptomycin. Compared to daptomycin, vancomycin showed a lower microbiological cure rate (OR = 0.58, 95% CI = 0.41∼0.82, I2 = 0%, P = 0.002) and clinical cure rate (OR = 0.53, 95% CI = 0.42∼0.68, I2 = 3%, P < 0.00001), as well as more adverse events (OR = 3.21, 95% CI = 1.43∼7.19, I2 = 59%, P = 0.005). CONCLUSION The efficacy of vancomycin in treating Staphylococcus aureus bacteraemia is still excellent but slightly inferior in adverse events. However, this does not affect its use as a first-line drug. Daptomycin is expected to be a better antimicrobial drug.
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Affiliation(s)
- Guanxuanzi Zhang
- Medical School of Chinese PLA, Graduate School of Chinese PLA General Hospital, Beijing, China; Center of Medicine Clinical Research, Department of Pharmacy, Medical Supplies Center, PLA General Hospital, Beijing, China
| | - Na Zhang
- Center of Medicine Clinical Research, Department of Pharmacy, Medical Supplies Center, PLA General Hospital, Beijing, China
| | - Juan Xu
- Center of Medicine Clinical Research, Department of Pharmacy, Medical Supplies Center, PLA General Hospital, Beijing, China
| | - Tianli Yang
- Medical School of Chinese PLA, Graduate School of Chinese PLA General Hospital, Beijing, China; Center of Medicine Clinical Research, Department of Pharmacy, Medical Supplies Center, PLA General Hospital, Beijing, China
| | - Hong Yin
- Center of Medicine Clinical Research, Department of Pharmacy, Medical Supplies Center, PLA General Hospital, Beijing, China.
| | - Yun Cai
- Center of Medicine Clinical Research, Department of Pharmacy, Medical Supplies Center, PLA General Hospital, Beijing, China.
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3
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Aguglia E, Chines E, Stefani S, Cafiso V. New Antimicrobial Resistance Strategies: An Adaptive Resistance Network Conferring Reduced Glycopeptide Susceptibility in VISA. Antibiotics (Basel) 2023; 12:antibiotics12040783. [PMID: 37107145 PMCID: PMC10135003 DOI: 10.3390/antibiotics12040783] [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: 03/07/2023] [Revised: 04/13/2023] [Accepted: 04/18/2023] [Indexed: 04/29/2023] Open
Abstract
Background: Vancomycin-intermediate Staphylococcus aureus (VISA) emerges typically in the healthcare-associated methicillin-resistant S. aureus and more rarely in community-acquired S. aureus (CA-MRSA). VISA is a serious concern for public health due to its association with persistent infections, the failure of vancomycin treatment, and poor clinical outcomes. Currently, the burden of VISA is somewhat high, even though vancomycin is the mainstay treatment for severe MRSA infections. The molecular mechanisms of reduced glycopeptide susceptibility in S. aureus are constantly under investigation but have still not yet been fully characterized. Methods: Our goal was to investigate the reduced glycopeptide susceptibility mechanisms emerging in a VISA CA-MRSA versus its vancomycin-susceptible (VSSA) CA-MRSA parents in a hospitalized patient undergoing glycopeptide treatment. Comparative integrated omics, Illumina MiSeq whole-genome sequencing (WGS), RNA-Seq, and bioinformatics were performed. Results: Through a comparison of VISA CA-MRSA vs. its VSSA CA-MRSA parent, mutational and transcriptomic adaptations were found in a pool of genes involved, directly or indirectly, in the biosynthesis of the glycopeptide target conferring or supporting the VISA phenotype, and its cross-resistance with daptomycin. This pool included key genes responsible for the biosynthesis of the peptidoglycan precursors, i.e., D-Ala, the D-Ala-D-Ala dipeptide termini of the pentapeptide, and its incorporation in the nascent pentapeptide, as key targets of the glycopeptide resistance. Furthermore, accessory glycopeptide-target genes involved in the pathways corroborated the key adaptations, and thus, supported the acquisition of the VISA phenotype i.e., transporters, nucleotide metabolism genes, and transcriptional regulators. Finally, transcriptional changes were also found in computationally predicted cis-acting small antisense RNA triggering genes related both to the key or accessory adaptive pathways. Conclusion: Our investigation describes an adaptive resistance pathway acquired under antimicrobial therapy conferring reduced glycopeptide susceptibility in a VISA CA-MRSA due to a comprehensive network of mutational and transcriptional adaptations in genes involved in pathways responsible for the biosynthesis of glycopeptide's target or supporters of the key resistance path.
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Affiliation(s)
- Elvira Aguglia
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Eleonora Chines
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Stefania Stefani
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Viviana Cafiso
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
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Zhang B, Phetsang W, Stone MRL, Kc S, Butler MS, Cooper MA, Elliott AG, Łapińska U, Voliotis M, Tsaneva-Atanasova K, Pagliara S, Blaskovich MAT. Synthesis of vancomycin fluorescent probes that retain antimicrobial activity, identify Gram-positive bacteria, and detect Gram-negative outer membrane damage. Commun Biol 2023; 6:409. [PMID: 37055536 PMCID: PMC10102067 DOI: 10.1038/s42003-023-04745-x] [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: 06/22/2022] [Accepted: 03/22/2023] [Indexed: 04/15/2023] Open
Abstract
Antimicrobial resistance is an urgent threat to human health, and new antibacterial drugs are desperately needed, as are research tools to aid in their discovery and development. Vancomycin is a glycopeptide antibiotic that is widely used for the treatment of Gram-positive infections, such as life-threatening systemic diseases caused by methicillin-resistant Staphylococcus aureus (MRSA). Here we demonstrate that modification of vancomycin by introduction of an azide substituent provides a versatile intermediate that can undergo copper-catalysed azide-alkyne cycloaddition (CuAAC) reaction with various alkynes to readily prepare vancomycin fluorescent probes. We describe the facile synthesis of three probes that retain similar antibacterial profiles to the parent vancomycin antibiotic. We demonstrate the versatility of these probes for the detection and visualisation of Gram-positive bacteria by a range of methods, including plate reader quantification, flow cytometry analysis, high-resolution microscopy imaging, and single cell microfluidics analysis. In parallel, we demonstrate their utility in measuring outer-membrane permeabilisation of Gram-negative bacteria. The probes are useful tools that may facilitate detection of infections and development of new antibiotics.
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Affiliation(s)
- Bing Zhang
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Wanida Phetsang
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - M Rhia L Stone
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Sanjaya Kc
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Mark S Butler
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Matthew A Cooper
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Alysha G Elliott
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Urszula Łapińska
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4Q, UK
| | - Margaritis Voliotis
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Department of Mathematics, University of Exeter, Stocker Road, Exeter, UK
| | - Krasimira Tsaneva-Atanasova
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Department of Mathematics, University of Exeter, Stocker Road, Exeter, UK
- EPSRC Hub for Quantitative Modelling in Healthcare, University of Exeter, Exeter, EX4 4QJ, UK
- Department of Bioinformatics and Mathematical Modelling, Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, 105 Acad. G. Bonchev Street, 1113, Sofia, Bulgaria
| | - Stefano Pagliara
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4Q, UK
| | - Mark A T Blaskovich
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia.
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5
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Lee D, Lee Y, Hye Shin S, Min Choi S, Hyeon Lee S, Jeong S, Jang S, Kee JM. A simple protein histidine kinase activity assay for high-throughput inhibitor screening. Bioorg Chem 2023; 130:106232. [DOI: 10.1016/j.bioorg.2022.106232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/15/2022] [Accepted: 10/26/2022] [Indexed: 11/11/2022]
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Aqib AI, Alsayeqh AF. Vancomycin drug resistance, an emerging threat to animal and public health. Front Vet Sci 2022; 9:1010728. [PMID: 36387389 PMCID: PMC9664514 DOI: 10.3389/fvets.2022.1010728] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 09/21/2022] [Indexed: 11/03/2023] Open
Abstract
The need to supply quality food for the growing human population has led to the revolutionization of food production and processing in recent years. Meanwhile, food production sources are at risk of microbial attack, while the use of antibiotics to counter them is posing another threat to food safety and security. Vancomycin was used as the first line of defense against multiple drug-resistant bacteria salient of which is methicillin-resistant S. aureus. The emergence of the vancomycin resistance gene in bacteria impairs the efficacy of antibiotics on the one hand while its harmful residues impart food safety concerns on the other. Currently, a novel set of resistance genes "Van cluster" is circulating in a wider range of bacteria. Considerable economic losses in terms of low production and food safety are associated with this emerging resistance. The current review focuses on the emergence of vancomycin resistance and its impact on food safety. The review proposes the need for further research on the probable routes, mechanisms, and implications of vancomycin resistance from animals to humans and vice versa.
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Affiliation(s)
- Amjad Islam Aqib
- Department of Medicine, Cholistan University of Veterinary and Animal Sciences, Bahawalpur, Pakistan
| | - Abdullah F. Alsayeqh
- Department of Veterinary Medicine, College of Agriculture and Veterinary Medicine, Qassim University, Buraidah, Qassim, Saudi Arabia
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7
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Mutation in the Two-Component System Regulator YycH Leads to Daptomycin Tolerance in Methicillin-Resistant Staphylococcus aureus upon Evolution with a Population Bottleneck. Microbiol Spectr 2022; 10:e0168722. [PMID: 35913149 PMCID: PMC9431245 DOI: 10.1128/spectrum.01687-22] [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] [Indexed: 11/20/2022] Open
Abstract
Adaptive laboratory evolution (ALE) is a useful tool to study the evolution of antibiotic tolerance in bacterial populations under diverse environmental conditions. The role of population bottlenecks in the evolution of tolerance has been investigated in Escherichia coli, but not in a more clinically relevant pathogen, methicillin-resistant Staphylococcus aureus (MRSA). In this study, we used ALE to evolve MRSA under repetitive daptomycin treatment and incorporated population bottlenecks following antibiotic exposure. We observed that the populations finally attained a tolerance mutation in the yycH gene after 2 weeks of evolution with population bottlenecks, and additional mutations in yycI and several other genes further increased the tolerance level. The tolerant populations also became resistant to another glycopeptide antibiotic, vancomycin. Through proteomics, we showed that yycH and yycI mutations led to the loss of function of the proteins and downregulated the WalKR two-component system and the downstream players, including the autolysin Atl and amidase Sle1, which are important for cell wall metabolism. Overall, our study offers new insights into the evolution of daptomycin tolerance under population bottlenecking conditions, which are commonly faced by pathogens during infection; the study also identified new mutations conferring daptomycin tolerance and revealed the proteome alterations in the evolved tolerant populations. IMPORTANCE Although population bottlenecks are known to influence the evolutionary dynamics of microbial populations, how such bottlenecks affect the evolution of tolerance to antibiotics in a clinically relevant methicillin-resistant S. aureus (MRSA) pathogen are still unclear. Here, we performed in vitro evolution of MRSA under cyclic daptomycin treatment and applied population bottlenecks following the treatment. We showed that under these experimental conditions, MRSA populations finally attained mutations in yycH, yycI, and several other genes that led to daptomycin tolerance. The discovered yycH and yycI mutations caused early termination of the genes and loss of function of the proteins, and they subsequently downregulated the expression of proteins controlled by the WalKR two-component system, such as Atl and Sle1. In addition, we compared our proteomics data with multiple studies on distinct daptomycin-tolerant MRSA mutants to identify proteins with a consistent expression pattern that could serve as biological markers for daptomycin tolerance in MRSA.
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8
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Bellali S, Haddad G, Iwaza R, Fontanini A, Hisada A, Ominami Y, Raoult D, Khalil JB. Antimicrobial susceptibility testing for Gram positive cocci towards vancomycin using scanning electron microscopy. CURRENT RESEARCH IN MICROBIAL SCIENCES 2022; 3:100154. [PMID: 35909629 PMCID: PMC9325908 DOI: 10.1016/j.crmicr.2022.100154] [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] [Indexed: 11/26/2022] Open
Abstract
The rapid detection of resistant bacteria has become a challenge for microbiologists worldwide. Numerous pathogens that cause nosocomial infections are still being treated empirically and have developed resistance mechanisms against key antibiotics. Thus, one of the challenges for researchers has been to develop rapid antimicrobial susceptibility testing (AST) to detect resistant isolates, ensuring better antibiotic stewardship. In this study, we established a proof-of-concept for a new strategy of phenotypic AST on Gram-positive cocci towards vancomycin using scanning electron microscopy (SEM). Our study evaluated the profiling of Enterococcus faecalis, Enterococcus faecium and Staphylococcus aureus after brief incubation with vancomycin. Sixteen isolates were analysed aiming to detect ultrastructural modifications at set timepoints, comparing bacteria with and without vancomycin. After optimising slides preparation and micrographs acquisition, two analytical strategies were used. The high magnification micrographs served to analyse the division of cocci based on the ratio of septa, along with the bacterial size. Susceptible strains with vancomycin showed a reduced septa percentage and the average surface area was consequently double that of the controls. The resistant bacteria revealed multiple septa occurring at advanced timepoints. Low magnification micrographs made it possible to quantify the pixels at different timepoints, confirming the profiling of cocci towards vancomycin. This new phenotypic AST strategy proved to be a promising tool to discriminate between resistant and susceptible cocci within an hour of contact with vancomycin. The analysis strategies applied here would potentially allow the creation of artificial intelligence algorithms for septa detection and bacterial quantification, subsequently creating a rapid automated SEM-AST assay.
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Affiliation(s)
- Sara Bellali
- Institut Hospitalo-Universitaire Méditerranée Infection, Marseille 13385, France
| | - Gabriel Haddad
- Institut Hospitalo-Universitaire Méditerranée Infection, Marseille 13385, France
- Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), UMR Microbes Evolution Phylogeny and Infections (MEPHI), Marseille 13385, France
| | - Rim Iwaza
- Institut Hospitalo-Universitaire Méditerranée Infection, Marseille 13385, France
- Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), UMR Microbes Evolution Phylogeny and Infections (MEPHI), Marseille 13385, France
| | - Anthony Fontanini
- Institut Hospitalo-Universitaire Méditerranée Infection, Marseille 13385, France
| | - Akiko Hisada
- Hitachi, Ltd., Research & Development Group, 1-280, Higashi-Koigakubo, Kokubunji-shi, Tokyo 185-8601, Japan
| | - Yusuke Ominami
- Hitachi High-Tech Corporation, 882 Ichige, Hitachinaka-shi, Ibaraki-ken 312-8504, Japan
| | - Didier Raoult
- Institut Hospitalo-Universitaire Méditerranée Infection, Marseille 13385, France
- Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), UMR Microbes Evolution Phylogeny and Infections (MEPHI), Marseille 13385, France
| | - Jacques Bou Khalil
- Institut Hospitalo-Universitaire Méditerranée Infection, Marseille 13385, France
- Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), UMR Microbes Evolution Phylogeny and Infections (MEPHI), Marseille 13385, France
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Divergent Effects of Peptidoglycan Carboxypeptidase DacA on Intrinsic β-Lactam and Vancomycin Resistance. Microbiol Spectr 2022; 10:e0173422. [PMID: 35758683 PMCID: PMC9430164 DOI: 10.1128/spectrum.01734-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Vancomycin and β-lactams are clinically important antibiotics that inhibit the formation of peptidoglycan cross-links, but their binding targets are different. The binding target of vancomycin is d-alanine-d-alanine (d-Ala-d-Ala), whereas that of β-lactam is penicillin-binding proteins (PBPs). In this study, we revealed the divergent effects of peptidoglycan (PG) carboxypeptidase DacA on vancomycin and β-lactam resistance in Escherichia coli and Bacillus subtilis. The deletion of DacA induced sensitivity to most β-lactams, whereas it induced strong resistance toward vancomycin. Notably, both phenotypes did not have a strong association with ld-transpeptidases, which are necessary for the formation of PG 3-3 cross-links and covalent bonds between PG and an Lpp outer membrane (OM) lipoprotein. Vancomycin resistance was induced by an increased amount of decoy d-Ala-d-Ala residues within PG, whereas β-lactam sensitivity was associated with physical interactions between DacA and PBPs. The presence of an OM permeability barrier strongly strengthened vancomycin resistance, but it significantly weakened β-lactam sensitivity. Collectively, our results revealed two distinct functions of DacA, which involved inverse modulation of bacterial resistance to clinically important antibiotics, β-lactams and vancomycin, and presented evidence for a link between DacA and PBPs. IMPORTANCE Bacterial PG hydrolases play important roles in various aspects of bacterial physiology, including cytokinesis, PG synthesis, quality control of PG, PG recycling, and stress adaptation. Of all the PG hydrolases, the role of PG carboxypeptidases is poorly understood, especially regarding their impacts on antibiotic resistance. We have revealed two distinct functions of PG carboxypeptidase DacA with respect to antibiotic resistance. The deletion of DacA led to sensitivity to most β-lactams, while it caused strong resistance to vancomycin. Our study provides novel insights into the roles of PG carboxypeptidases in the regulation of antibiotic resistance and a potential clue for the development of a drug to improve the clinical efficacy of β-lactam antibiotics.
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10
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Encapsulation of the septal cell wall protects Streptococcus pneumoniae from its major peptidoglycan hydrolase and host defenses. PLoS Pathog 2022; 18:e1010516. [PMID: 35731836 PMCID: PMC9216600 DOI: 10.1371/journal.ppat.1010516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 04/11/2022] [Indexed: 11/19/2022] Open
Abstract
Synthesis of the capsular polysaccharide, a major virulence factor for many pathogenic bacteria, is required for bacterial survival within the infected host. In Streptococcus pneumoniae, Wze, an autophosphorylating tyrosine kinase, and Wzd, a membrane protein required for Wze autophosphorylation, co-localize at the division septum and guarantee the presence of capsule at this subcellular location. To determine how bacteria regulate capsule synthesis, we studied pneumococcal proteins that interact with Wzd and Wze using bacterial two hybrid assays and fluorescence microscopy. We found that Wzd interacts with Wzg, the putative ligase that attaches capsule to the bacterial cell wall, and recruits it to the septal area. This interaction required residue V56 of Wzd and both the transmembrane regions and DNA-PPF domain of Wzg. When compared to the wild type, Wzd null pneumococci lack capsule at midcell, bind the peptidoglycan hydrolase LytA better and are more susceptible to LytA-induced lysis, and are less virulent in a zebrafish embryo infection model. In this manuscript, we propose that the Wzd/Wze pair guarantees full encapsulation of pneumococcal bacteria by recruiting Wzg to the division septum, ensuring that capsule attachment is coordinated with peptidoglycan synthesis. Impairing the encapsulation process, at localized subcellular sites, may facilitate elimination of bacteria by strategies that target the pneumococcal peptidoglycan.
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11
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Abstract
Cell division and cell wall synthesis in staphylococci need to be precisely coordinated and controlled to allow the cell to multiply while maintaining its nearly spherical shape. The mechanisms ensuring correct placement of the division plane and synthesis of new cell wall have been studied intensively. However, hitherto unknown factors and proteins are likely to play key roles in this complex interplay. Here, we identified and investigated a protein with a major influence on cell morphology in Staphylococcus aureus. The protein, named SmdA (for staphylococcal morphology determinant A), is a membrane protein with septum-enriched localization. By CRISPRi knockdown and overexpression combined with different microscopy techniques, we demonstrated that proper levels of SmdA were necessary for cell division, including septum formation and cell splitting. We also identified conserved residues in SmdA that were critical for its functionality. Pulldown and bacterial two-hybrid interaction experiments showed that SmdA interacted with several known cell division and cell wall synthesis proteins, including penicillin-binding proteins (PBPs) and EzrA. Notably, SmdA also affected susceptibility to cell wall targeting antibiotics, particularly in methicillin-resistant S. aureus (MRSA). Together, our results showed that S. aureus was dependent on balanced amounts of membrane attached SmdA to carry out proper cell division.
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12
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Ferraro NJ, Kim S, Im W, Pires MM. Systematic Assessment of Accessibility to the Surface of Staphylococcus aureus. ACS Chem Biol 2021; 16:2527-2536. [PMID: 34609132 DOI: 10.1021/acschembio.1c00604] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Proteins from bacterial foes, antimicrobial peptides, and host immune proteins must navigate past a dense layer of bacterial surface biomacromolecules to reach the peptidoglycan (PG) layer of Gram-positive bacteria. A subclass of molecules (e.g., antibiotics with intracellular targets) also must permeate through the PG (in a molecular sieving manner) to reach the cytoplasmic membrane. Despite the biological and therapeutic importance of surface accessibility, systematic analyses in live bacterial cells have been lacking. We describe a live cell fluorescence assay that is robust, shows a high level of reproducibility, and reports on the permeability of molecules to and within the PG scaffold. Moreover, our study shows that teichoic acids impede the permeability of molecules of a wide range of sizes and chemical composition.
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Affiliation(s)
- Noel J. Ferraro
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Seonghoon Kim
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul 02455, Republic of Korea
| | - Wonpil Im
- Departments of Biological Sciences, Chemistry, and Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Marcos M. Pires
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
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13
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Saraiva BM, Krippahl L, Filipe SR, Henriques R, Pinho MG. eHooke: A tool for automated image analysis of spherical bacteria based on cell cycle progression. BIOLOGICAL IMAGING 2021; 1:e3. [PMID: 35036921 PMCID: PMC8724265 DOI: 10.1017/s2633903x21000027] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 08/18/2021] [Accepted: 09/07/2021] [Indexed: 01/18/2023]
Abstract
Fluorescence microscopy is a critical tool for cell biology studies on bacterial cell division and morphogenesis. Because the analysis of fluorescence microscopy images evolved beyond initial qualitative studies, numerous images analysis tools were developed to extract quantitative parameters on cell morphology and organization. To understand cellular processes required for bacterial growth and division, it is particularly important to perform such analysis in the context of cell cycle progression. However, manual assignment of cell cycle stages is laborious and prone to user bias. Although cell elongation can be used as a proxy for cell cycle progression in rod-shaped or ovoid bacteria, that is not the case for cocci, such as Staphylococcus aureus. Here, we describe eHooke, an image analysis framework developed specifically for automated analysis of microscopy images of spherical bacterial cells. eHooke contains a trained artificial neural network to automatically classify the cell cycle phase of individual S. aureus cells. Users can then apply various functions to obtain biologically relevant information on morphological features of individual cells and cellular localization of proteins, in the context of the cell cycle.
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Affiliation(s)
- Bruno M. Saraiva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ludwig Krippahl
- NOVA LINCS, Departamento de Informática, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Sérgio R. Filipe
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- UCIBIO-REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Ricardo Henriques
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Mariana G. Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
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14
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Wang TSA, Chen PL, Chen YCS, Hung HM, Huang JY. Selectively Targeting and Differentiating Vancomycin-Resistant Staphylococcus aureus via Dual Synthetic Fluorescent Probes. ACS Infect Dis 2021; 7:2584-2590. [PMID: 34410687 DOI: 10.1021/acsinfecdis.1c00235] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Many Staphylococcus bacteria are pathogenic and harmful to humans. Noticeably, some Staphylococcus, including vancomycin-resistant S. aureus (VRSA), have become notoriously resistant to antibiotics and have spread rapidly, becoming threats to public health. Here, we designed a dual fluorescent probe scheme combining siderophores and antibiotics as the guiding units to selectively target VRSA and vancomycin-sensitive S. aureus (VSSA) in complex bacterial samples. Siderophore-mediated iron uptake is the key pathway by which S. aureus acquires iron in limited environments. Therefore, the siderophore-derivative probe could differentiate between S. aureus and other bacteria. Moreover, by fine-tuning the vancomycin-derivative probes, we could selectively target only VSSA, further differentiating VRSA and VSSA. Finally, by combining the siderophore-derivative probe and the vancomycin-derivative probe, we successfully targeted and differentiated between VRSA and VSSA in complicated bacterial mixtures.
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Affiliation(s)
| | - Pin-Lung Chen
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan (R.O.C.)
| | - Yi-Chen Sarah Chen
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan (R.O.C.)
| | - Hsuan-Min Hung
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan (R.O.C.)
| | - Jhih-Yi Huang
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan (R.O.C.)
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15
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Apostolos AJ, Ferraro NJ, Dalesandro BE, Pires MM. SaccuFlow: A High-Throughput Analysis Platform to Investigate Bacterial Cell Wall Interactions. ACS Infect Dis 2021; 7:2483-2491. [PMID: 34291914 DOI: 10.1021/acsinfecdis.1c00255] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Bacterial cell walls are formidable barriers that protect bacterial cells against external insults and oppose internal turgor pressure. While cell wall composition is variable across species, peptidoglycan is the principal component of all cell walls. Peptidoglycan is a mesh-like scaffold composed of cross-linked strands that can be heavily decorated with anchored proteins. The biosynthesis and remodeling of peptidoglycan must be tightly regulated by cells because disruption to this biomacromolecule is lethal. This essentiality is exploited by the human innate immune system in resisting colonization and by a number of clinically relevant antibiotics that target peptidoglycan biosynthesis. Evaluation of molecules or proteins that interact with peptidoglycan can be a complicated and, typically, qualitative effort. We have developed a novel assay platform (SaccuFlow) that preserves the native structure of bacterial peptidoglycan and is compatible with high-throughput flow cytometry analysis. We show that the assay is facile and versatile as demonstrated by its compatibility with sacculi from Gram-positive bacteria, Gram-negative bacteria, and mycobacteria. Finally, we highlight the utility of this assay to assess the activity of sortase A from Staphylococcus aureus against potential antivirulence agents.
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Affiliation(s)
- Alexis J. Apostolos
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Noel J. Ferraro
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Brianna E. Dalesandro
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Marcos M. Pires
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
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16
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Wang W, Sun B. VraCP regulates cell wall metabolism and antibiotic resistance in vancomycin-intermediate Staphylococcus aureus strain Mu50. J Antimicrob Chemother 2021; 76:1712-1723. [PMID: 33948657 PMCID: PMC8212773 DOI: 10.1093/jac/dkab113] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/13/2021] [Indexed: 01/29/2023] Open
Abstract
Objectives Vancomycin-intermediate Staphylococcus aureus (VISA) is increasingly being reported. Previous studies have shown that vraC and vraP may be involved in vancomycin resistance, although the molecular mechanism remains elusive. Methods The vraC (SAV0577), vraP (SAV0578) and vraCP mutants were constructed in Mu50 by allelic replacement. Some common VISA phenotypes were assessed in mutants, such as, susceptibility to the cell wall-associated antibiotics, cell wall thickness, autolysis activity and growth rate. RT-qPCR was performed to reveal the differential genes associated with these phenotypes. The binding abilities of VraC and VraCP to the promoters of target genes were determined by electrophoretic mobility shift assay (EMSA). Results VraP forms a stable complex with VraC to preserve their own stability. The vraC, vraP and vraCP mutants exhibited increased susceptibility to the cell wall-associated antibiotics and thinner cell walls compared with the WT strain. Consistent with these phenotypes, RT-qPCR revealed downregulated transcription of glyS, sgtB, ddl and alr2, which are involved in cell wall biosynthesis. Moreover, the transcription of cell wall hydrolysis genes, including sceD, lytM and isaA, was significantly downregulated, supporting the finding that mutants exhibited reduced autolysis rates. EMSA confirmed that both VraC and VraCP can directly bind to the sceD, lytM and isaA promoter regions containing the consensus sequence (5′-TTGTAAN2AN3TGTAA-3′), which is crucial for the binding of VraCP with target genes. GFP-reporter assays further revealed VraC and VraCP can enhance promoter activity of sceD to positively regulate its expression. Conclusions vraCP plays a significant role in cell wall metabolism and antibiotic resistance in Mu50.
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Affiliation(s)
- Wanying Wang
- Department of Oncology, The First Affiliated Hospital, University of Science and Technology of China, Hefei, People's Republic of China
| | - Baolin Sun
- Department of Oncology, The First Affiliated Hospital, University of Science and Technology of China, Hefei, People's Republic of China
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17
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Vila T, Kong EF, Montelongo-Jauregui D, Van Dijck P, Shetty AC, McCracken C, Bruno VM, Jabra-Rizk MA. Therapeutic implications of C. albicans-S. aureus mixed biofilm in a murine subcutaneous catheter model of polymicrobial infection. Virulence 2021; 12:835-851. [PMID: 33682623 PMCID: PMC7946022 DOI: 10.1080/21505594.2021.1894834] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Biofilm-associated polymicrobial infections tend to be challenging to treat. Candida albicans and Staphylococcus aureus are leading pathogens due to their ability to form biofilms on medical devices. However, the therapeutic implications of their interactions in a host is largely unexplored. In this study, we used a mouse subcutaneous catheter model for in vivo-grown polymicrobial biofilms to validate our in vitro findings on C. albicans-mediated enhanced S. aureus tolerance to vancomycin in vivo. Comparative assessment of S. aureus recovery from catheters with single- or mixed-species infection demonstrated failure of vancomycin against S. aureus in mice with co-infected catheters. To provide some mechanistic insights, RNA-seq analysis was performed on catheter biofilms to delineate transcriptional modulations during polymicrobial infections. C. albicans induced the activation of the S. aureus biofilm formation network via down-regulation of the lrg operon, repressor of autolysis, and up-regulation of the ica operon and production of polysaccharide intercellular adhesin (PIA), indicating an increase in eDNA production, and extracellular polysaccharide matrix, respectively. Interestingly, virulence factors important for disseminated infections, and superantigen-like proteins were down-regulated during mixed-species infection, whereas capsular polysaccharide genes were up-regulated, signifying a strategy favoring survival, persistence and host immune evasion. In vitro follow-up experiments using DNA enzymatic digestion, lrg operon mutant strains, and confocal scanning microscopy confirmed the role of C. albicans-mediated enhanced eDNA production in mixed-biofilms on S. aureus tolerance to vancomycin. Combined, these findings provide mechanistic insights into the therapeutic implications of interspecies interactions, underscoring the need for novel strategies to overcome limitations of current therapies.
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Affiliation(s)
- Taissa Vila
- Department of Oncology and Diagnostic Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA
| | - Eric F Kong
- Department of Oncology and Diagnostic Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA
| | - Daniel Montelongo-Jauregui
- Department of Oncology and Diagnostic Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA
| | - Patrick Van Dijck
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven-Heverlee, Belgium.,VIB-KU Leuven Center for Microbiology, Flanders, Belgium
| | - Amol C Shetty
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Carrie McCracken
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Vincent M Bruno
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mary Ann Jabra-Rizk
- Department of Oncology and Diagnostic Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA.,Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
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18
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Gajdiss M, Monk IR, Bertsche U, Kienemund J, Funk T, Dietrich A, Hort M, Sib E, Stinear TP, Bierbaum G. YycH and YycI Regulate Expression of Staphylococcus aureus Autolysins by Activation of WalRK Phosphorylation. Microorganisms 2020; 8:microorganisms8060870. [PMID: 32526915 PMCID: PMC7355866 DOI: 10.3390/microorganisms8060870] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/05/2020] [Accepted: 06/07/2020] [Indexed: 11/16/2022] Open
Abstract
Staphylococcus aureus is a facultative pathogen that can encode numerous antibiotic resistance and immune evasion genes and can cause severe infections. Reduced susceptibility to last resort antibiotics such as vancomycin and daptomycin is often associated with mutations in walRK, an essential two-component regulatory system (TCS). This study focuses on the WalK accessory membrane proteins YycH and YycI and their influence on WalRK phosphorylation. Depletion of YycH and YycI by antisense RNA caused an impaired autolysis, indicating a positive regulatory function on WalK as has been previously described. Phosphorylation assays with full-length recombinant proteins in phospholipid liposomes showed that YycH and YycI stimulate WalK activity and that both regulatory proteins are needed for full activation of the WalK kinase. This was validated in vivo through examining the phosphorylation status of WalR using Phos-tag SDS-PAGE with a yycHI deletion mutant exhibiting reduced levels of phosphorylated WalR. In the yycHI knockdown strain, muropeptide composition of the cell wall was not affected, however, the wall teichoic acid content was increased. In conclusion, a direct modulation of WalRK phosphorylation activity by the accessory proteins YycH and YycI is reported both in vitro and in vivo. Taken together, our results show that YycH and YycI are important in the direct regulation of WalRK-dependent cell wall metabolism.
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Affiliation(s)
- Mike Gajdiss
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53125 Bonn, Germany; (M.G.); (J.K.); (T.F.); (A.D.); (M.H.); (E.S.)
| | - Ian R. Monk
- Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC 3010, Australia; (I.R.M.); (T.P.S.)
| | - Ute Bertsche
- Department of Infection Biology, University of Tuebingen, 72076 Tuebingen, Germany;
| | - Janina Kienemund
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53125 Bonn, Germany; (M.G.); (J.K.); (T.F.); (A.D.); (M.H.); (E.S.)
| | - Tanja Funk
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53125 Bonn, Germany; (M.G.); (J.K.); (T.F.); (A.D.); (M.H.); (E.S.)
| | - Alina Dietrich
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53125 Bonn, Germany; (M.G.); (J.K.); (T.F.); (A.D.); (M.H.); (E.S.)
| | - Michael Hort
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53125 Bonn, Germany; (M.G.); (J.K.); (T.F.); (A.D.); (M.H.); (E.S.)
| | - Esther Sib
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53125 Bonn, Germany; (M.G.); (J.K.); (T.F.); (A.D.); (M.H.); (E.S.)
| | - Timothy P. Stinear
- Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC 3010, Australia; (I.R.M.); (T.P.S.)
| | - Gabriele Bierbaum
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53125 Bonn, Germany; (M.G.); (J.K.); (T.F.); (A.D.); (M.H.); (E.S.)
- Correspondence:
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19
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Nabb DL, Song S, Kluthe KE, Daubert TA, Luedtke BE, Nuxoll AS. Polymicrobial Interactions Induce Multidrug Tolerance in Staphylococcus aureus Through Energy Depletion. Front Microbiol 2019; 10:2803. [PMID: 31866973 PMCID: PMC6906149 DOI: 10.3389/fmicb.2019.02803] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 11/19/2019] [Indexed: 02/01/2023] Open
Abstract
Staphylococcus aureus is responsible for a high number of relapsing infections, which are often mediated by the protective nature of biofilms. Polymicrobial biofilms appear to be more tolerant to antibiotic treatment, however, the underlying mechanisms for this remain unclear. Polymicrobial biofilm and planktonic cultures formed by S. aureus and Candida albicans are 10- to 100-fold more tolerant to oxacillin, vancomycin, ciprofloxacin, delafloxacin, and rifampicin compared to monocultures of S. aureus. The possibility of C. albicans matrix components physically blocking antibiotic molecules from reaching S. aureus was ruled out as oxacillin, ciprofloxacin, delafloxacin, and rifampicin were able to diffuse through polymicrobial biofilms. Based on previous findings that S. aureus forms drug tolerant persister cells through ATP depletion, we examined nutrient deprivation by determining glucose availability, which indirectly correlates to ATP production via the tricarboxylic acid (TCA) cycle. Using an extracellular glucose assay, we confirmed that S. aureus and C. albicans polymicrobial cultures depleted available glucose faster than the respective monocultures. Supporting this finding, S. aureus exhibited decreased TCA cycle activity, specifically fumarase expression, when grown in the presence of C. albicans. In addition, S. aureus grown in polymicrobial cultures displayed 2.2-fold more cells with low membrane potential and a 13% reduction in intracellular ATP concentrations than in monocultures. Collectively, these data demonstrate that decreased metabolic activity through nutrient deprivation is a mechanism for increased antibiotic tolerance within polymicrobial cultures.
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Affiliation(s)
- Dan L Nabb
- Department of Biology, University of Nebraska at Kearney, Kearney, NE, United States
| | - Seoyoung Song
- Department of Biology, University of Nebraska at Kearney, Kearney, NE, United States
| | - Kennedy E Kluthe
- Department of Biology, University of Nebraska at Kearney, Kearney, NE, United States
| | - Trevor A Daubert
- Department of Biology, University of Nebraska at Kearney, Kearney, NE, United States
| | - Brandon E Luedtke
- Department of Biology, University of Nebraska at Kearney, Kearney, NE, United States
| | - Austin S Nuxoll
- Department of Biology, University of Nebraska at Kearney, Kearney, NE, United States
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20
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Szymczak P, Rau MH, Monteiro JM, Pinho MG, Filipe SR, Vogensen FK, Zeidan AA, Janzen T. A comparative genomics approach for identifying host-range determinants in Streptococcus thermophilus bacteriophages. Sci Rep 2019; 9:7991. [PMID: 31142793 PMCID: PMC6541646 DOI: 10.1038/s41598-019-44481-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 05/07/2019] [Indexed: 12/17/2022] Open
Abstract
Comparative genomics has proven useful in exploring the biodiversity of phages and understanding phage-host interactions. This knowledge is particularly useful for phages infecting Streptococcus thermophilus, as they constitute a constant threat during dairy fermentations. Here, we explore the genetic diversity of S. thermophilus phages to identify genetic determinants with a signature for host specificity, which could be linked to the bacterial receptor genotype. A comparative genomic analysis was performed on 142 S. thermophilus phage genomes, 55 of which were sequenced in this study. Effectively, 94 phages were assigned to the group cos (DT1), 36 to the group pac (O1205), six to the group 5093, and six to the group 987. The core genome-based phylogeny of phages from the two dominating groups and their receptor binding protein (RBP) phylogeny corresponded to the phage host-range. A role of RBP in host recognition was confirmed by constructing a fluorescent derivative of the RBP of phage CHPC951, followed by studying the binding of the protein to the host strain. Furthermore, the RBP phylogeny of the cos group was found to correlate with the host genotype of the exocellular polysaccharide-encoding operon. These findings provide novel insights towards developing strategies to combat phage infections in dairies.
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Affiliation(s)
- Paula Szymczak
- Bacterial Physiology, R&D, Chr. Hansen A/S, 2970, Hørsholm, Denmark
- Department of Food Science, University of Copenhagen, 1958, Frederiksberg, Denmark
| | - Martin Holm Rau
- Bacterial Physiology, R&D, Chr. Hansen A/S, 2970, Hørsholm, Denmark
| | - João M Monteiro
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
| | - Mariana G Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
| | - Sérgio Raposo Filipe
- UCIBIO-REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
- Laboratory of Bacterial Cell Surfaces and Pathogenesis, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
| | - Finn Kvist Vogensen
- Department of Food Science, University of Copenhagen, 1958, Frederiksberg, Denmark
| | - Ahmad A Zeidan
- Bacterial Physiology, R&D, Chr. Hansen A/S, 2970, Hørsholm, Denmark
| | - Thomas Janzen
- Bacterial Physiology, R&D, Chr. Hansen A/S, 2970, Hørsholm, Denmark.
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21
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Dhanda G, Sarkar P, Samaddar S, Haldar J. Battle against Vancomycin-Resistant Bacteria: Recent Developments in Chemical Strategies. J Med Chem 2018; 62:3184-3205. [DOI: 10.1021/acs.jmedchem.8b01093] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Geetika Dhanda
- Antimicrobial Research Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Paramita Sarkar
- Antimicrobial Research Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Sandip Samaddar
- Antimicrobial Research Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Jayanta Haldar
- Antimicrobial Research Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
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22
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Synthesis of an oleic acid based pH-responsive lipid and its application in nanodelivery of vancomycin. Int J Pharm 2018; 550:149-159. [DOI: 10.1016/j.ijpharm.2018.08.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 08/06/2018] [Accepted: 08/16/2018] [Indexed: 12/20/2022]
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23
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Phillips-Jones MK, Harding SE. Antimicrobial resistance (AMR) nanomachines-mechanisms for fluoroquinolone and glycopeptide recognition, efflux and/or deactivation. Biophys Rev 2018; 10:347-362. [PMID: 29525835 PMCID: PMC5899746 DOI: 10.1007/s12551-018-0404-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 02/05/2018] [Indexed: 12/11/2022] Open
Abstract
In this review, we discuss mechanisms of resistance identified in bacterial agents Staphylococcus aureus and the enterococci towards two priority classes of antibiotics-the fluoroquinolones and the glycopeptides. Members of both classes interact with a number of components in the cells of these bacteria, so the cellular targets are also considered. Fluoroquinolone resistance mechanisms include efflux pumps (MepA, NorA, NorB, NorC, MdeA, LmrS or SdrM in S. aureus and EfmA or EfrAB in the enterococci) for removal of fluoroquinolone from the intracellular environment of bacterial cells and/or protection of the gyrase and topoisomerase IV target sites in Enterococcus faecalis by Qnr-like proteins. Expression of efflux systems is regulated by GntR-like (S. aureus NorG), MarR-like (MgrA, MepR) regulators or a two-component signal transduction system (TCS) (S. aureus ArlSR). Resistance to the glycopeptide antibiotic teicoplanin occurs via efflux regulated by the TcaR regulator in S. aureus. Resistance to vancomycin occurs through modification of the D-Ala-D-Ala target in the cell wall peptidoglycan and removal of high affinity precursors, or by target protection via cell wall thickening. Of the six Van resistance types (VanA-E, VanG), the VanA resistance type is considered in this review, including its regulation by the VanSR TCS. We describe the recent application of biophysical approaches such as the hydrodynamic technique of analytical ultracentrifugation and circular dichroism spectroscopy to identify the possible molecular effector of the VanS receptor that activates expression of the Van resistance genes; both approaches demonstrated that vancomycin interacts with VanS, suggesting that vancomycin itself (or vancomycin with an accessory factor) may be an effector of vancomycin resistance. With 16 and 19 proteins or protein complexes involved in fluoroquinolone and glycopeptide resistances, respectively, and the complexities of bacterial sensing mechanisms that trigger and regulate a wide variety of possible resistance mechanisms, we propose that these antimicrobial resistance mechanisms might be considered complex 'nanomachines' that drive survival of bacterial cells in antibiotic environments.
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Affiliation(s)
- Mary K Phillips-Jones
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, Loughborough, Leicestershire, UK.
| | - Stephen E Harding
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, Loughborough, Leicestershire, UK
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24
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McGuinness WA, Malachowa N, DeLeo FR. Vancomycin Resistance in Staphylococcus aureus
. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2017; 90:269-281. [PMID: 28656013 PMCID: PMC5482303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The evolution of Staphylococcus aureus during the modern antibiotic era has been delineated by distinct strain emergence events, many of which include acquisition of antibiotic resistance. The relative high burden of methicillin-resistant S. aureus (MRSA) in healthcare and community settings is a major concern worldwide. Vancomycin, a glycopeptide antibiotic that inhibits cell wall biosynthesis, remains a drug of choice for treatment of severe MRSA infections. S. aureus strains exhibiting increased resistance to vancomycin, known as vancomycin intermediate-resistant S. aureus (VISA) (MIC = 4-8 µg/mL), were discovered in the 1990s. The molecular basis of resistance in VISA is polygenic and involves stepwise mutations in genes encoding molecules predominantly involved in cell envelope biosynthesis. S. aureus isolates with complete resistance to vancomycin (MIC ≥ 16 µg/mL) are termed vancomycin-resistant S. aureus (VRSA)-they were first reported in the U.S. in 2002. Resistance in VRSA is conferred by the vanA gene and operon, which is present on a plasmid. Although treatment of VRSA infections is challenging, the total number of human VRSA infections to date is limited (14 in the U.S.). By comparison, the burden of VISA is relatively high and the molecular mechanisms of resistance are less well-defined. VISA are associated with persistent infections, vancomycin treatment failure, and poor clinical outcomes. Here, we review in brief progress made toward understanding the acquisition of antibiotic resistance in S. aureus, with an emphasis on the molecular mechanisms underlying vancomycin resistance.
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Affiliation(s)
| | | | - Frank R. DeLeo
- To whom all correspondence should be addressed: Frank R. DeLeo, Ph.D., Tel.: 406-363-9315,
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25
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Aw J, Widjaja F, Ding Y, Mu J, Liang Y, Xing B. Enzyme-responsive reporter molecules for selective localization and fluorescence imaging of pathogenic biofilms. Chem Commun (Camb) 2017; 53:3330-3333. [DOI: 10.1039/c6cc09296a] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A novel enzyme-responsive reporter molecule (ERM-1) for selective localization of AmpC in pathogenic biofilms.
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Affiliation(s)
- Junxin Aw
- Division of Chemistry and Biological Chemistry
- School of Physical & Mathematical Sciences
- Nanyang Technological University
- Singapore
- Singapore
| | - Frances Widjaja
- Division of Chemistry and Biological Chemistry
- School of Physical & Mathematical Sciences
- Nanyang Technological University
- Singapore
- Singapore
| | - Yichen Ding
- Centre for Environmental Life Sciences Engineering (SCELSE)
- School of Biological Sciences
- Nanyang Technological University
- Singapore
- Singapore
| | - Jing Mu
- Division of Chemistry and Biological Chemistry
- School of Physical & Mathematical Sciences
- Nanyang Technological University
- Singapore
- Singapore
| | - Yang Liang
- Centre for Environmental Life Sciences Engineering (SCELSE)
- School of Biological Sciences
- Nanyang Technological University
- Singapore
- Singapore
| | - Bengang Xing
- Division of Chemistry and Biological Chemistry
- School of Physical & Mathematical Sciences
- Nanyang Technological University
- Singapore
- Singapore
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26
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Hu Q, Peng H, Rao X. Molecular Events for Promotion of Vancomycin Resistance in Vancomycin Intermediate Staphylococcus aureus. Front Microbiol 2016; 7:1601. [PMID: 27790199 PMCID: PMC5062060 DOI: 10.3389/fmicb.2016.01601] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 09/26/2016] [Indexed: 12/14/2022] Open
Abstract
Vancomycin has been used as the last resort in the clinical treatment of serious Staphylococcus aureus infections. Vancomycin-intermediate S. aureus (VISA) was discovered almost two decades ago. Aside from the vancomycin-intermediate phenotype, VISA strains from the clinic or laboratory exhibited common characteristics, such as thickened cell walls, reduced autolysis, and attenuated virulence. However, the genetic mechanisms responsible for the reduced vancomycin susceptibility in VISA are varied. The comparative genomics of vancomycin-susceptible S. aureus (VSSA)/VISA pairs showed diverse genetic mutations in VISA; only a small number of these mutations have been experimentally verified. To connect the diversified genotypes and common phenotypes in VISA, we reviewed the genetic alterations in the relative determinants, including mutations in the vraTSR, graSR, walKR, stk1/stp1, rpoB, clpP, and cmk genes. Especially, we analyzed the mechanism through which diverse mutations mediate vancomycin resistance. We propose a unified model that integrates diverse gene functions and complex biochemical processes in VISA upon the action of vancomycin.
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Affiliation(s)
- Qiwen Hu
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Huagang Peng
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Xiancai Rao
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
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Commensal Protection of Staphylococcus aureus against Antimicrobials by Candida albicans Biofilm Matrix. mBio 2016; 7:mBio.01365-16. [PMID: 27729510 PMCID: PMC5061872 DOI: 10.1128/mbio.01365-16] [Citation(s) in RCA: 183] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Biofilm-associated polymicrobial infections, particularly those involving fungi and bacteria, are responsible for significant morbidity and mortality and tend to be challenging to treat. Candida albicans and Staphylococcus aureus specifically are considered leading opportunistic fungal and bacterial pathogens, respectively, mainly due to their ability to form biofilms on catheters and indwelling medical devices. However, the impact of mixed-species biofilm growth on therapy remains largely understudied. In this study, we investigated the influence of C. albicans secreted cell wall polysaccharides on the response of S. aureus to antibacterial agents in biofilm. Results demonstrated significantly enhanced tolerance for S. aureus to drugs in the presence of C. albicans or its secreted cell wall polysaccharide material. Fluorescence confocal time-lapse microscopy revealed impairment of drug diffusion through the mixed biofilm matrix. Using C. albicans mutant strains with modulated cell wall polysaccharide expression, exogenous supplementation, and enzymatic degradation, the C. albicans-secreted β-1,3-glucan cell wall component was identified as the key matrix constituent providing the bacteria with enhanced drug tolerance. Further, antibody labeling demonstrated rapid coating of the bacteria by the C. albicans matrix material. Importantly, via its effect on the fungal biofilm matrix, the antifungal caspofungin sensitized the bacteria to the drugs. Understanding such symbiotic interactions with clinical relevance between microbial species in biofilms will greatly aid in overcoming the limitations of current therapies and in defining potential new targets for treating polymicrobial infections. The fungus Candida albicans and the bacterium Staphylococcus aureus are important microbial pathogens responsible for the majority of infections in hospitalized patients and are often coisolated from a host. In this study, we demonstrated that when grown together, the fungus provides the bacterium with enhanced tolerance to antimicrobial drugs. This process was mediated by polysaccharides secreted by the fungal cell into the environment. The biofilm matrix formed by these polysaccharides prevented penetration by the drugs and provided the bacteria with protection. Importantly, we show that by inhibiting the production of the fungal polysaccharides, a specific antifungal agent indirectly sensitized the bacteria to antimicrobials. Understanding the therapeutic implications of the interactions between these two diverse microbial species will aid in overcoming the limitations of current therapies and in defining new targets for treating complex polymicrobial infections.
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Tavares AC, Fernandes PB, Carballido-López R, Pinho MG. MreC and MreD Proteins Are Not Required for Growth of Staphylococcus aureus. PLoS One 2015; 10:e0140523. [PMID: 26470021 PMCID: PMC4607420 DOI: 10.1371/journal.pone.0140523] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 09/28/2015] [Indexed: 12/31/2022] Open
Abstract
The transmembrane proteins MreC and MreD are present in a wide variety of bacteria and are thought to be involved in cell shape determination. Together with the actin homologue MreB and other morphological elements, they play an essential role in the synthesis of the lateral cell wall in rod-shaped bacteria. In ovococcus, which lack MreB homologues, mreCD are also essential and have been implicated in peripheral cell wall synthesis. In this work we addressed the possible roles of MreC and MreD in the spherical pathogen Staphylococcus aureus. We show that MreC and MreD are not essential for cell viability and do not seem to affect cell morphology, cell volume or cell cycle control. MreC and MreD localize preferentially to the division septa, but do not appear to influence peptidoglycan composition, nor the susceptibility to different antibiotics and to oxidative and osmotic stress agents. Our results suggest that the function of MreCD in S. aureus is not critical for cell division and cell shape determination.
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Affiliation(s)
- Andreia C. Tavares
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Pedro B. Fernandes
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Rut Carballido-López
- INRA, UMR 1319 Micalis, F-78350, Jouy-en-Josas, France
- AgroParisTech, UMR Micalis, F-78350, Jouy-en-Josas, France
| | - Mariana G. Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- * E-mail:
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29
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Monteiro JM, Fernandes PB, Vaz F, Pereira AR, Tavares AC, Ferreira MT, Pereira PM, Veiga H, Kuru E, VanNieuwenhze MS, Brun YV, Filipe SR, Pinho MG. Cell shape dynamics during the staphylococcal cell cycle. Nat Commun 2015; 6:8055. [PMID: 26278781 PMCID: PMC4557339 DOI: 10.1038/ncomms9055] [Citation(s) in RCA: 152] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 07/13/2015] [Indexed: 12/04/2022] Open
Abstract
Staphylococcus aureus is an aggressive pathogen and a model organism to study cell division in sequential orthogonal planes in spherical bacteria. However, the small size of staphylococcal cells has impaired analysis of changes in morphology during the cell cycle. Here we use super-resolution microscopy and determine that S. aureus cells are not spherical throughout the cell cycle, but elongate during specific time windows, through peptidoglycan synthesis and remodelling. Both peptidoglycan hydrolysis and turgor pressure are required during division for reshaping the flat division septum into a curved surface. In this process, the septum generates less than one hemisphere of each daughter cell, a trait we show is common to other cocci. Therefore, cell surface scars of previous divisions do not divide the cells in quadrants, generating asymmetry in the daughter cells. Our results introduce a need to reassess the models for division plane selection in cocci. Staphylococci are spherical bacteria that divide in sequential orthogonal planes. Here, the authors use super-resolution microscopy to show that staphylococcal cells elongate before dividing, and that the division septum generates less than one hemisphere of each daughter cell, generating asymmetry.
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Affiliation(s)
- João M Monteiro
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Pedro B Fernandes
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Filipa Vaz
- Laboratory of Bacterial Cell Surfaces and Pathogenesis, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Ana R Pereira
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Andreia C Tavares
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Maria T Ferreira
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Pedro M Pereira
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Helena Veiga
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Erkin Kuru
- 1] Department of Chemistry, Indiana University Bloomington, Bloomington, Indiana 47405, USA [2] Department of Biology, Indiana University Bloomington, Bloomington, Indiana 47405, USA
| | | | - Yves V Brun
- Department of Biology, Indiana University Bloomington, Bloomington, Indiana 47405, USA
| | - Sérgio R Filipe
- Laboratory of Bacterial Cell Surfaces and Pathogenesis, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Mariana G Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
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Singh A, Prasad KN, Misra R, Rahman M, Singh SK, Rai RP, Tripathi A, Srivastava JK. Increasing Trend of Heterogeneous Vancomycin Intermediate Staphylococcus aureus in a Tertiary Care Center of Northern India. Microb Drug Resist 2015; 21:545-50. [PMID: 26430942 DOI: 10.1089/mdr.2015.0004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Heterogeneous vancomycin intermediate Staphylococcus aureus (hVISA) strains are increasingly reported, and their association with vancomycin treatment failure is a well-known problem worldwide. A total of 500 clinical isolates of methicillin-resistant S. aureus were screened for hVISA by four different methods from May 2011 to May 2014. The number of strains screened for hVISA from May to April in 2011-2012, 2012-2013, and 2013-2014 were 198, 123, and 179, respectively. hVISA strains were studied by transmission electron microscopy (TEM) for cell wall thickness and also for their ability to form biofilm on a polystyrene microtiter plate. hVISA strains detected by four different methods-brain heart infusion agar with vancomycin with 4 mg/L/gradient plate/macro E-test/and glycopeptide resistance detection (GRD) E test-were as follows: 11.6%/10%/9%, and 9.5% in 2011-2012, 12.1%/9.7%/8.9%, and 10.5% in 2012-2013, and 13.9%/11.7%/11.1%, and 12.8% in 2013-2014, respectively. Population analysis profile-area under curve analysis confirmed hVISA in 4.5% (9/198), 6.5% (8/123), and 6.7% (12/179) in respective years; 24% (7/29) of hVISA isolates were nonsusceptible to daptomycin. TEM showed a significant increase in cell wall thickness of hVISA isolates (p<0.001) with a distinct reduction in their biofilm formation ability.
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Affiliation(s)
- Avinash Singh
- 1 Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences , Lucknow, Uttar Pradesh, India .,2 Amity Institute of Biotechnology, Amity University Uttar Pradesh , Lucknow, Uttar Pradesh, India
| | - Kashi Nath Prasad
- 1 Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences , Lucknow, Uttar Pradesh, India
| | - Richa Misra
- 1 Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences , Lucknow, Uttar Pradesh, India
| | - Mohibur Rahman
- 1 Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences , Lucknow, Uttar Pradesh, India
| | - Satyendra Kumar Singh
- 1 Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences , Lucknow, Uttar Pradesh, India
| | - Ravi Prakash Rai
- 1 Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences , Lucknow, Uttar Pradesh, India
| | - Aparna Tripathi
- 1 Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences , Lucknow, Uttar Pradesh, India
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A mutation of RNA polymerase β' subunit (RpoC) converts heterogeneously vancomycin-intermediate Staphylococcus aureus (hVISA) into "slow VISA". Antimicrob Agents Chemother 2015; 59:4215-25. [PMID: 25941225 DOI: 10.1128/aac.00135-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 04/28/2015] [Indexed: 12/13/2022] Open
Abstract
Various mutations in the rpoB gene, which encodes the RNA polymerase β subunit, are associated with increased vancomycin (VAN) resistance in vancomycin-intermediate Staphylococcus aureus (VISA) and heterogeneously VISA (hVISA) strains. We reported that rpoB mutations are also linked to the expression of the recently found "slow VISA" (sVISA) phenotype (M. Saito, Y. Katayama, T. Hishinuma, A. Iwamoto, Y. Aiba, K Kuwahara-Arai, L. Cui, M. Matsuo, N. Aritaka, and K. Hiramatsu, Antimicrob Agents Chemother 58:5024-5035, 2014, http://dx.doi.org/10.1128/AAC.02470-13). Because RpoC and RpoB are components of RNA polymerase, we examined the effect of the rpoC(P440L) mutation on the expression of the sVISA phenotype in the Mu3fdh2*V6-5 strain (V6-5), which was derived from a previously reported hVISA strain with the VISA phenotype. V6-5 had an extremely prolonged doubling time (DT) (72 min) and high vancomycin MIC (16 mg/liter). However, the phenotype of V6-5 was unstable, and the strain frequently reverted to hVISA with concomitant loss of low growth rate, cell wall thickness, and reduced autolysis. Whole-genome sequencing of phenotypic revertant strain V6-5-L1 and comparison with V6-5 revealed a second mutation, F562L, in rpoC. Introduction of the wild-type (WT) rpoC gene using a multicopy plasmid resolved the sVISA phenotype of V6-5, indicating that the rpoC(P440L) mutant expressed the sVISA phenotype in hVISA. To investigate the mechanisms of resistance in the sVISA strain, we independently isolated an additional 10 revertants to hVISA and VISA. In subsequent whole-genome analysis, we identified compensatory mutations in the genes of three distinct functional categories: the rpoC gene itself as regulatory mutations, peptidoglycan biosynthesis genes, and relQ, which is involved in the stringent response. It appears that the rpoC(P440L) mutation causes the sVISA phenotype by augmenting cell wall peptidoglycan synthesis and through the control of the stringent response.
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Rosário AL, Sena FV, Batista AP, Oliveira TF, Athayde D, Pereira MM, Brito JA, Archer M. Expression, purification, crystallization and preliminary X-ray diffraction analysis of a type II NADH:quinone oxidoreductase from the human pathogen Staphylococcus aureus. Acta Crystallogr F Struct Biol Commun 2015; 71:477-82. [PMID: 25849513 PMCID: PMC4388187 DOI: 10.1107/s2053230x15005178] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 03/13/2015] [Indexed: 05/14/2024] Open
Abstract
In recent years, type II NADH dehydrogenases (NDH-IIs) have emerged as potential drug targets for a wide range of human disease causative agents. In this work, the NDH-II enzyme from the Gram-positive human pathogen Staphylococcus aureus was recombinantly expressed in Escherichia coli, purified, crystallized and a crystallographic data set was collected at a wavelength of 0.873 Å. The crystals belonged to the orthorhombic space group P212121, with unit-cell parameters a = 81.8, b = 86.0, c = 269.9 Å, contained four monomers per asymmetric unit and diffracted to a resolution of 3.32 Å. A molecular-replacement solution was obtained and model building and refinement are currently under way.
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Affiliation(s)
- Ana Lúcia Rosário
- Instituto de Tecnologia Química e Biológica – António Xavier, Universidade Nova de Lisboa, Avenida República, 2780-157 Oeiras, Portugal
| | - Filipa V. Sena
- Instituto de Tecnologia Química e Biológica – António Xavier, Universidade Nova de Lisboa, Avenida República, 2780-157 Oeiras, Portugal
| | - Ana P. Batista
- Instituto de Tecnologia Química e Biológica – António Xavier, Universidade Nova de Lisboa, Avenida República, 2780-157 Oeiras, Portugal
| | - Tânia F. Oliveira
- Instituto de Tecnologia Química e Biológica – António Xavier, Universidade Nova de Lisboa, Avenida República, 2780-157 Oeiras, Portugal
| | - Diogo Athayde
- Instituto de Tecnologia Química e Biológica – António Xavier, Universidade Nova de Lisboa, Avenida República, 2780-157 Oeiras, Portugal
| | - Manuela M. Pereira
- Instituto de Tecnologia Química e Biológica – António Xavier, Universidade Nova de Lisboa, Avenida República, 2780-157 Oeiras, Portugal
| | - José A. Brito
- Instituto de Tecnologia Química e Biológica – António Xavier, Universidade Nova de Lisboa, Avenida República, 2780-157 Oeiras, Portugal
| | - Margarida Archer
- Instituto de Tecnologia Química e Biológica – António Xavier, Universidade Nova de Lisboa, Avenida República, 2780-157 Oeiras, Portugal
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Mielich-Süss B, Lopez D. Molecular mechanisms involved in Bacillus subtilis biofilm formation. Environ Microbiol 2015; 17:555-65. [PMID: 24909922 PMCID: PMC4188541 DOI: 10.1111/1462-2920.12527] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Accepted: 06/01/2014] [Indexed: 02/02/2023]
Abstract
Biofilms are the predominant lifestyle of bacteria in natural environments, and they severely impact our societies in many different fashions. Therefore, biofilm formation is a topic of growing interest in microbiology, and different bacterial models are currently studied to better understand the molecular strategies that bacteria undergo to build biofilms. Among those, biofilms of the soil-dwelling bacterium Bacillus subtilis are commonly used for this purpose. Bacillus subtilis biofilms show remarkable architectural features that are a consequence of sophisticated programmes of cellular specialization and cell-cell communication within the community. Many laboratories are trying to unravel the biological role of the morphological features of biofilms, as well as exploring the molecular basis underlying cellular differentiation. In this review, we present a general perspective of the current state of knowledge of biofilm formation in B. subtilis and thereby placing a special emphasis on summarizing the most recent discoveries in the field.
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Affiliation(s)
| | - Daniel Lopez
- Research Centre for Infectious Diseases (ZINF). University of Würzburg, Germany
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34
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Chiang WL, Lin TT, Sureshbabu R, Chia WT, Hsiao HC, Liu HY, Yang CM, Sung HW. A rapid drug release system with a NIR light-activated molecular switch for dual-modality photothermal/antibiotic treatments of subcutaneous abscesses. J Control Release 2015; 199:53-62. [DOI: 10.1016/j.jconrel.2014.12.011] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 11/14/2014] [Accepted: 12/10/2014] [Indexed: 10/24/2022]
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35
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Koch G, Yepes A, Förstner KU, Wermser C, Stengel ST, Modamio J, Ohlsen K, Foster KR, Lopez D. Evolution of resistance to a last-resort antibiotic in Staphylococcus aureus via bacterial competition. Cell 2014; 158:1060-1071. [PMID: 25171407 PMCID: PMC4163622 DOI: 10.1016/j.cell.2014.06.046] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 04/28/2014] [Accepted: 06/23/2014] [Indexed: 01/02/2023]
Abstract
Antibiotic resistance is a key medical concern, with antibiotic use likely being an important cause. However, here we describe an alternative route to clinically relevant antibiotic resistance that occurs solely due to competitive interactions among bacterial cells. We consistently observe that isolates of Methicillin-resistant Staphylococcus aureus diversify spontaneously into two distinct, sequentially arising strains. The first evolved strain outgrows the parent strain via secretion of surfactants and a toxic bacteriocin. The second is resistant to the bacteriocin. Importantly, this second strain is also resistant to intermediate levels of vancomycin. This so-called VISA (vancomycin-intermediate S. aureus) phenotype is seen in many hard-to-treat clinical isolates. This strain diversification also occurs during in vivo infection in a mouse model, which is consistent with the fact that both coevolved phenotypes resemble strains commonly found in clinic. Our study shows how competition between coevolving bacterial strains can generate antibiotic resistance and recapitulate key clinical phenotypes.
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Affiliation(s)
- Gudrun Koch
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany
| | - Ana Yepes
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany
| | - Konrad U Förstner
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Charlotte Wermser
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany
| | - Stephanie T Stengel
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany
| | - Jennifer Modamio
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany
| | - Knut Ohlsen
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Kevin R Foster
- Department of Zoology, University of Oxford, Oxford OX1 3QU, UK; Oxford Centre for Integrative Systems Biology, University of Oxford, Oxford OX1 3QU, UK
| | - Daniel Lopez
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany.
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36
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Gardete S, Tomasz A. Mechanisms of vancomycin resistance in Staphylococcus aureus. J Clin Invest 2014; 124:2836-40. [PMID: 24983424 DOI: 10.1172/jci68834] [Citation(s) in RCA: 324] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Vancomycin is a glycopeptide antibiotic used for the treatment of Gram-positive bacterial infections. Traditionally, it has been used as a drug of last resort; however, clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) strains with decreased susceptibility to vancomycin (vancomycin intermediate-resistant S. aureus [VISA]) and more recently with high-level vancomycin resistance (vancomycin-resistant S. aureus [VRSA]) have been described in the clinical literature. The rare VRSA strains carry transposon Tn1546, acquired from vancomycin-resistant Enterococcus faecalis, which is known to alter cell wall structure and metabolism, but the resistance mechanisms in VISA isolates are less well defined. Herein, we review selected mechanistic aspects of resistance in VISA and summarize biochemical studies on cell wall synthesis in a VRSA strain. Finally, we recapitulate a model that integrates common mechanistic features of VRSA and VISA strains and is consistent with the mode of action of vancomycin.
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37
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Tra VN, Dube DH. Glycans in pathogenic bacteria--potential for targeted covalent therapeutics and imaging agents. Chem Commun (Camb) 2014; 50:4659-73. [PMID: 24647371 PMCID: PMC4049282 DOI: 10.1039/c4cc00660g] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A substantial obstacle to the existing treatment of bacterial diseases is the lack of specific probes that can be used to diagnose and treat pathogenic bacteria in a selective manner while leaving the microbiome largely intact. To tackle this problem, there is an urgent need to develop pathogen-specific therapeutics and diagnostics. Here, we describe recent evidence that indicates distinctive glycans found exclusively on pathogenic bacteria could form the basis of targeted therapeutic and diagnostic strategies. In particular, we highlight the use of metabolic oligosaccharide engineering to covalently deliver therapeutics and imaging agents to bacterial glycans.
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Affiliation(s)
- Van N Tra
- Bowdoin College, Department of Chemistry & Biochemistry, Brunswick, Maine, USA.
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Reconstruction of mreB expression in Staphylococcus aureus via a collection of new integrative plasmids. Appl Environ Microbiol 2014; 80:3868-78. [PMID: 24747904 DOI: 10.1128/aem.00759-14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Protein localization has been traditionally explored in unicellular organisms, whose ease of genetic manipulation facilitates molecular characterization. The two rod-shaped bacterial models Escherichia coli and Bacillus subtilis have been prominently used for this purpose and have displaced other bacteria whose challenges for genetic manipulation have complicated any study of cell biology. Among these bacteria is the spherical pathogenic bacterium Staphylococcus aureus. In this report, we present a new molecular toolbox that facilitates gene deletion in staphylococci in a 1-step recombination process and additional vectors that facilitate the insertion of diverse reporter fusions into newly identified neutral loci of the S. aureus chromosome. Insertion of the reporters does not add any antibiotic resistance genes to the chromosomes of the resultant strains, thereby making them amenable for further genetic manipulations. We used this toolbox to reconstitute the expression of mreB in S. aureus, a gene that encodes an actin-like cytoskeletal protein which is absent in coccal cells and is presumably lost during the course of speciation. We observed that in S. aureus, MreB is organized in discrete structures in association with the membrane, leading to an unusual redistribution of the cell wall material. The production of MreB also caused cell enlargement, but it did not revert staphylococcal shape. We present interactions of MreB with key staphylococcal cell wall-related proteins. This work facilitates the use S. aureus as a model system in exploring diverse aspects of cellular microbiology.
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Chudobova D, Dostalova S, Blazkova I, Michalek P, Ruttkay-Nedecky B, Sklenar M, Nejdl L, Kudr J, Gumulec J, Tmejova K, Konecna M, Vaculovicova M, Hynek D, Masarik M, Kynicky J, Kizek R, Adam V. Effect of ampicillin, streptomycin, penicillin and tetracycline on metal resistant and non-resistant Staphylococcus aureus. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2014; 11:3233-55. [PMID: 24651395 PMCID: PMC3987032 DOI: 10.3390/ijerph110303233] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 02/18/2014] [Accepted: 02/24/2014] [Indexed: 12/29/2022]
Abstract
There is an arising and concerning issue in the field of bacterial resistance, which is confirmed by the number of deaths associated with drug-resistant bacterial infections. The aim of this study was to compare the effects of antibiotics on Staphylococcus aureus non-resistant strain and strains resistant to cadmium or lead ions. Metal resistant strains were created by the gradual addition of 2 mM solution of metal ions (cadmium or lead) to the S. aureus culture. An increasing antimicrobial effect of ampicillin, streptomycin, penicillin and tetracycline (0, 10, 25, 50, 75, 150, 225 and 300 µM) on the resistant strains was observed using a method of growth curves. A significant growth inhibition (compared to control) of cadmium resistant cells was observed in the presence of all the four different antibiotics. On the other hand, the addition of streptomycin and ampicillin did not inhibit the growth of lead resistant strain. Other antibiotics were still toxic to the bacterial cells. Significant differences in the morphology of cell walls were indicated by changes in the cell shape. Our data show that the presence of metal ions in the urban environment may contribute to the development of bacterial strain resistance to other substances including antibiotics, which would have an impact on public health.
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Affiliation(s)
- Dagmar Chudobova
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, Brno CZ-613 00, Czech Republic.
| | - Simona Dostalova
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, Brno CZ-613 00, Czech Republic.
| | - Iva Blazkova
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, Brno CZ-613 00, Czech Republic.
| | - Petr Michalek
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, Brno CZ-613 00, Czech Republic.
| | - Branislav Ruttkay-Nedecky
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, Brno CZ-613 00, Czech Republic.
| | - Matej Sklenar
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, Brno CZ-613 00, Czech Republic.
| | - Lukas Nejdl
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, Brno CZ-613 00, Czech Republic.
| | - Jiri Kudr
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, Brno CZ-613 00, Czech Republic.
| | - Jaromir Gumulec
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, Brno CZ-616 00, Czech Republic.
| | - Katerina Tmejova
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, Brno CZ-613 00, Czech Republic.
| | - Marie Konecna
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, Brno CZ-613 00, Czech Republic.
| | - Marketa Vaculovicova
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, Brno CZ-613 00, Czech Republic.
| | - David Hynek
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, Brno CZ-616 00, Czech Republic.
| | - Michal Masarik
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, Brno CZ-616 00, Czech Republic.
| | - Jindrich Kynicky
- Karel Englis College, Sujanovo nam. 356/1, Brno CZ-602 00, Czech Republic.
| | - Rene Kizek
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, Brno CZ-613 00, Czech Republic.
| | - Vojtech Adam
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, Brno CZ-613 00, Czech Republic.
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Clp chaperones and proteases are central in stress survival, virulence and antibiotic resistance of Staphylococcus aureus. Int J Med Microbiol 2013; 304:142-9. [PMID: 24457183 DOI: 10.1016/j.ijmm.2013.11.009] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Intracellular proteolysis carried out by energy-dependent proteases is one of the most conserved biological processes. In all cells proteolysis maintains and shapes the cellular proteome by ridding the cell of damaged proteins and by regulating abundance of functional proteins such as regulatory proteins. The ATP-dependent ClpP protease is highly conserved among eubacteria and in the chloroplasts and mitochondria of eukaryotic cells. In the serious human pathogen, Staphylococcus aureus inactivation of clpP rendered the bacterium avirulent emphasizing the central role of proteolysis in virulence. The contribution of the Clp proteins to virulence is likely to occur at multiple levels. First of all, both Clp ATPases and the Clp protease are central players in stress responses required to cope with the adverse conditions met in the host. The ClpP protease has a dual role herein, as it both eliminates stress-damaged proteins as well as ensures the timely degradation of major stress regulators such as Spx, LexA and CtsR. Additionally, as we will summarize in this review, Clp proteases and Clp chaperones impact on such central processes as virulence gene expression, cell wall metabolism, survival in stationary phase, and cell division. These observations together with recent findings that Clp proteins contribute to adaptation to antibiotics highlights the importance of this interesting proteolytic machinery both for understanding pathogenicity of the organism and for treating staphylococcal infections.
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Bunschoten A, Welling MM, Termaat MF, Sathekge M, van Leeuwen FWB. Development and Prospects of Dedicated Tracers for the Molecular Imaging of Bacterial Infections. Bioconjug Chem 2013; 24:1971-89. [PMID: 24200346 DOI: 10.1021/bc4003037] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- A. Bunschoten
- Department
of Radiology, Interventional Molecular Imaging Laboratory, Leiden University Medical Center, Leiden, The Netherlands
| | - M. M. Welling
- Department
of Radiology, Interventional Molecular Imaging Laboratory, Leiden University Medical Center, Leiden, The Netherlands
| | - M. F. Termaat
- Department
of Trauma Surgery, Leiden University Medical Center, Leiden, The Netherlands
| | - M. Sathekge
- Department of Nuclear Medicine, University of Pretoria & Steve Biko Academic Hospital, Pretoria, South Africa
| | - F. W. B. van Leeuwen
- Department
of Radiology, Interventional Molecular Imaging Laboratory, Leiden University Medical Center, Leiden, The Netherlands
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42
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Mann PA, Müller A, Xiao L, Pereira PM, Yang C, Ho Lee S, Wang H, Trzeciak J, Schneeweis J, dos Santos MM, Murgolo N, She X, Gill C, Balibar CJ, Labroli M, Su J, Flattery A, Sherborne B, Maier R, Tan CM, Black T, Önder K, Kargman S, Monsma FJ, Pinho MG, Schneider T, Roemer T. Murgocil is a highly bioactive staphylococcal-specific inhibitor of the peptidoglycan glycosyltransferase enzyme MurG. ACS Chem Biol 2013; 8:2442-51. [PMID: 23957438 DOI: 10.1021/cb400487f] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Modern medicine is founded on the discovery of penicillin and subsequent small molecules that inhibit bacterial peptidoglycan (PG) and cell wall synthesis. However, the discovery of new chemically and mechanistically distinct classes of PG inhibitors has become exceedingly rare, prompting speculation that intracellular enzymes involved in PG precursor synthesis are not 'druggable' targets. Here, we describe a β-lactam potentiation screen to identify small molecules that augment the activity of β-lactams against methicillin-resistant Staphylococcus aureus (MRSA) and mechanistically characterize a compound resulting from this screen, which we have named murgocil. We provide extensive genetic, biochemical, and structural modeling data demonstrating both in vitro and in whole cells that murgocil specifically inhibits the intracellular membrane-associated glycosyltransferase, MurG, which synthesizes the lipid II PG substrate that penicillin binding proteins (PBPs) polymerize and cross-link into the cell wall. Further, we demonstrate that the chemical synergy and cidality achieved between murgocil and the β-lactam imipenem is mediated through MurG dependent localization of PBP2 to the division septum. Collectively, these data validate our approach to rationally identify new target-specific bioactive β-lactam potentiation agents and demonstrate that murgocil now serves as a highly selective and potent chemical probe to assist our understanding of PG biosynthesis and cell wall biogenesis across Staphylococcal species.
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Affiliation(s)
- Paul A. Mann
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Anna Müller
- Institute
of Medical Microbiology, Immunology and Parasitology—Pharmaceutical
Microbiology Section, University of Bonn, Bonn, Germany
| | - Li Xiao
- Computational
Chemistry, Global Structure Chemistry, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Pedro M. Pereira
- Laboratory
of Bacterial Cell Biology, Instituto de Tecnologia Química
e Biológica, Universidade Nova de Lisboa, Avenida da República, 2781-901 Oeiras, Portugal
| | - Christine Yang
- Medicinal
Chemistry, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Sang Ho Lee
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Hao Wang
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Joanna Trzeciak
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Jonathan Schneeweis
- In Vitro Pharmacology, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Margarida Moreira dos Santos
- Laboratory
of Bacterial Cell Biology, Instituto de Tecnologia Química
e Biológica, Universidade Nova de Lisboa, Avenida da República, 2781-901 Oeiras, Portugal
| | - Nicholas Murgolo
- Research
Solutions, Bioinformatics, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Xinwei She
- Informatics
IT, Merck Inc., Boston, Massachusetts 02110, United States
| | - Charles Gill
- In Vivo Pharmacology, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Carl J. Balibar
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Marc Labroli
- Medicinal
Chemistry, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Jing Su
- Medicinal
Chemistry, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Amy Flattery
- In Vivo Pharmacology, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Brad Sherborne
- Computational
Chemistry, Global Structure Chemistry, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Richard Maier
- Procomcure Biotech GmbH, Krems a.d. Donau, Austria
- Division of Molecular
Dermatology, Department of Dermatology, Paracelsus Medical University, Salzburg, Austria
| | - Christopher M. Tan
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Todd Black
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Kamil Önder
- Procomcure Biotech GmbH, Krems a.d. Donau, Austria
- Division of Molecular
Dermatology, Department of Dermatology, Paracelsus Medical University, Salzburg, Austria
| | - Stacia Kargman
- In Vitro Pharmacology, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Frederick J Monsma
- In Vitro Pharmacology, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Mariana G. Pinho
- Laboratory
of Bacterial Cell Biology, Instituto de Tecnologia Química
e Biológica, Universidade Nova de Lisboa, Avenida da República, 2781-901 Oeiras, Portugal
| | - Tanja Schneider
- Institute
of Medical Microbiology, Immunology and Parasitology—Pharmaceutical
Microbiology Section, University of Bonn, Bonn, Germany
- German Centre for Infection Research (DZIF), partner site
Bonn-Cologne, Bonn, Germany
| | - Terry Roemer
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
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43
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Daptomycin-resistant Enterococcus faecalis diverts the antibiotic molecule from the division septum and remodels cell membrane phospholipids. mBio 2013; 4:mBio.00281-13. [PMID: 23882013 PMCID: PMC3735187 DOI: 10.1128/mbio.00281-13] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Treatment of multidrug-resistant enterococci has become a challenging clinical problem in hospitals around the world due to the lack of reliable therapeutic options. Daptomycin (DAP), a cell membrane-targeting cationic antimicrobial lipopeptide, is the only antibiotic with in vitro bactericidal activity against vancomycin-resistant enterococci (VRE). However, the clinical use of DAP against VRE is threatened by emergence of resistance during therapy, but the mechanisms leading to DAP resistance are not fully understood. The mechanism of action of DAP involves interactions with the cell membrane in a calcium-dependent manner, mainly at the level of the bacterial septum. Previously, we demonstrated that development of DAP resistance in vancomycin-resistant Enterococcus faecalis is associated with mutations in genes encoding proteins with two main functions, (i) control of the cell envelope stress response to antibiotics and antimicrobial peptides (LiaFSR system) and (ii) cell membrane phospholipid metabolism (glycerophosphoryl diester phosphodiesterase and cardiolipin synthase). In this work, we show that these VRE can resist DAP-elicited cell membrane damage by diverting the antibiotic away from its principal target (division septum) to other distinct cell membrane regions. DAP septal diversion by DAP-resistant E. faecalis is mediated by initial redistribution of cell membrane cardiolipin-rich microdomains associated with a single amino acid deletion within the transmembrane protein LiaF (a member of a three-component regulatory system [LiaFSR] involved in cell envelope homeostasis). Full expression of DAP resistance requires additional mutations in enzymes
(glycerophosphoryl diester phosphodiesterase and cardiolipin synthase) that alter cell membrane phospholipid content. Our findings describe a novel mechanism of bacterial resistance to cationic antimicrobial peptides. IMPORTANCE The emergence of antibiotic resistance in bacterial pathogens is a threat to public health. Understanding the mechanisms of resistance is of crucial importance to develop new strategies to combat multidrug-resistant microorganisms. Vancomycin-resistant enterococci (VRE) are one of the most recalcitrant hospital-associated pathogens against which new therapies are urgently needed. Daptomycin (DAP) is a calcium-decorated antimicrobial lipopeptide whose target is the bacterial cell membrane. A current paradigm suggests that Gram-positive bacteria become resistant to cationic antimicrobial peptides via an electrostatic repulsion of the antibiotic molecule from a more positively charged cell surface. In this work, we provide evidence that VRE use a novel strategy to avoid DAP-elicited killing. Instead of “repelling” the antibiotic from the cell surface, VRE diverts the antibiotic molecule from the septum and “traps” it in distinct membrane regions. We provide genetic and biochemical bases responsible for the mechanism of resistance and disclose new targets for potential antimicrobial development. The emergence of antibiotic resistance in bacterial pathogens is a threat to public health. Understanding the mechanisms of resistance is of crucial importance to develop new strategies to combat multidrug-resistant microorganisms. Vancomycin-resistant enterococci (VRE) are one of the most recalcitrant hospital-associated pathogens against which new therapies are urgently needed. Daptomycin (DAP) is a calcium-decorated antimicrobial lipopeptide whose target is the bacterial cell membrane. A current paradigm suggests that Gram-positive bacteria become resistant to cationic antimicrobial peptides via an electrostatic repulsion of the antibiotic molecule from a more positively charged cell surface. In this work, we provide evidence that VRE use a novel strategy to avoid DAP-elicited killing. Instead of “repelling” the antibiotic from the cell surface, VRE diverts the antibiotic molecule from the septum and “traps” it in distinct membrane regions. We provide genetic and biochemical bases responsible for the mechanism of resistance and disclose new targets for potential antimicrobial development.
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44
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Shao Q, Zheng Y, Dong X, Tang K, Yan X, Xing B. A Covalent Reporter of β-Lactamase Activity for Fluorescent Imaging and Rapid Screening of Antibiotic-Resistant Bacteria. Chemistry 2013; 19:10903-10. [DOI: 10.1002/chem.201301654] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Indexed: 01/16/2023]
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45
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Howden BP, Peleg AY, Stinear TP. The evolution of vancomycin intermediate Staphylococcus aureus (VISA) and heterogenous-VISA. INFECTION GENETICS AND EVOLUTION 2013; 21:575-82. [PMID: 23567819 DOI: 10.1016/j.meegid.2013.03.047] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/20/2013] [Accepted: 03/29/2013] [Indexed: 12/01/2022]
Abstract
Resistance to new antimicrobials is generally recognized in Staphylococcus aureus soon after they are released for clinical use. In the case of vancomycin, which was first released in the 1950s, resistance was not reported until the mid 1990s, with the description of vancomycin-intermediate S. aureus (VISA), and heterogenous-VISA (hVISA). Unraveling the complex genetic and cell wall structural changes conferring low-level vancomycin resistance in S. aureus has proved challenging. However the recent advances in high throughput whole-genome sequencing has played a key role in determining the breadth of bacterial chromosomal changes linked with resistance. Diverse mutations in a small number of staphylococcal regulatory genes, in particular walKR, graRS, vraSR and rpoB, have been associated with hVISA and VISA. Only a small number of these mutations have been experimentally proven to confer the resistance phenotype and some of these only partially contribute to resistance. It also appears that the evolution of VISA from VSSA is a step-wise process. Transcriptomics studies, and analysis of host pathogen interactions, indicate that the evolution of vancomycin-susceptible S. aureus to VISA is associated not only with antibiotic resistance, but with other changes likely to promote persistent infection. These include predicted alterations in central metabolism, altered expression of virulence associated factors, attenuated virulence in vivo, and alterations in susceptibility to host innate immune responses, together with reduced susceptibility to other antibiotics. In fact, current data suggests that hVISA and VISA represent a bacterial evolutionary state favoring persistence in the face of not only antibiotics, but also the host environment. The additional knowledge of staphylococcal biology that has been uncovered during the study of hVISA and VISA is significant. The present review will detail the current understanding of the evolutionary process in the generation of hVISA and VISA, and explore the diverse additional changes that occur in these strains.
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Affiliation(s)
- Benjamin P Howden
- Austin Centre for Infection Research (ACIR), Infectious Diseases Department, Austin Health, Heidelberg, Victoria, Australia; Microbiology Department, Austin Health, Heidelberg, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne, Victoria, Australia; Department of Microbiology, Monash University, Wellington Rd, Clayton, Victoria, Australia.
| | - Anton Y Peleg
- Department of Microbiology, Monash University, Wellington Rd, Clayton, Victoria, Australia; Division of Infectious Diseases, Beth Israel Deaconess Medical Center, Boston, MA, United States; Department of Infectious Diseases, The Alfred Hospital, Melbourne, Australia
| | - Timothy P Stinear
- Department of Microbiology and Immunology, University of Melbourne, Victoria, Australia; Department of Microbiology, Monash University, Wellington Rd, Clayton, Victoria, Australia
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Abstract
Many Gram-negative and Gram-positive bacteria recycle a significant proportion of the peptidoglycan components of their cell walls during their growth and septation. In many--and quite possibly all--bacteria, the peptidoglycan fragments are recovered and recycled. Although cell-wall recycling is beneficial for the recovery of resources, it also serves as a mechanism to detect cell-wall-targeting antibiotics and to regulate resistance mechanisms. In several Gram-negative pathogens, anhydro-MurNAc-peptide cell-wall fragments regulate AmpC β-lactamase induction. In some Gram-positive organisms, short peptides derived from the cell wall regulate the induction of both β-lactamase and β-lactam-resistant penicillin-binding proteins. The involvement of peptidoglycan recycling with resistance regulation suggests that inhibitors of the enzymes involved in the recycling might synergize with cell-wall-targeted antibiotics. Indeed, such inhibitors improve the potency of β-lactams in vitro against inducible AmpC β-lactamase-producing bacteria. We describe the key steps of cell-wall remodeling and recycling, the regulation of resistance mechanisms by cell-wall recycling, and recent advances toward the discovery of cell-wall-recycling inhibitors.
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Affiliation(s)
- Jarrod W Johnson
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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47
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Daptomycin-mediated reorganization of membrane architecture causes mislocalization of essential cell division proteins. J Bacteriol 2012; 194:4494-504. [PMID: 22661688 DOI: 10.1128/jb.00011-12] [Citation(s) in RCA: 226] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Daptomycin is a lipopeptide antibiotic used clinically for the treatment of certain types of Gram-positive infections, including those caused by methicillin-resistant Staphylococcus aureus (MRSA). Details of the mechanism of action of daptomycin continue to be elucidated, particularly the question of whether daptomycin acts on the cell membrane, the cell wall, or both. Here, we use fluorescence microscopy to directly visualize the interaction of daptomycin with the model Gram-positive bacterium Bacillus subtilis. We show that the first observable cellular effects are the formation of membrane distortions (patches of membrane) that precede cell death by more than 30 min. Membrane patches are able to recruit the essential cell division protein DivIVA. Recruitment of DivIVA correlates with membrane defects and changes in cell morphology, suggesting a localized alteration in the activity of enzymes involved in cell wall synthesis that could account for previously described effects of daptomycin on cell wall morphology and septation. Membrane defects colocalize with fluorescently labeled daptomycin, DivIVA, and fluorescent reporters of peptidoglycan biogenesis (Bocillin FL and BODIPY FL-vancomycin), suggesting that daptomycin plays a direct role in these events. Our results support a mechanism for daptomycin with a primary effect on cell membranes that in turn redirects the localization of proteins involved in cell division and cell wall synthesis, causing dramatic cell wall and membrane defects, which may ultimately lead to a breach in the cell membrane and cell death. These results help resolve the longstanding questions regarding the mechanism of action of this important class of antibiotics.
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48
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Boudreau MA, Fisher JF, Mobashery S. Messenger functions of the bacterial cell wall-derived muropeptides. Biochemistry 2012; 51:2974-90. [PMID: 22409164 DOI: 10.1021/bi300174x] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Bacterial muropeptides are soluble peptidoglycan structures central to recycling of the bacterial cell wall and messengers in diverse cell signaling events. Bacteria sense muropeptides as signals that antibiotics targeting cell-wall biosynthesis are present, and eukaryotes detect muropeptides during the innate immune response to bacterial infection. This review summarizes the roles of bacterial muropeptides as messengers, with a special emphasis on bacterial muropeptide structures and the relationship of structure to the biochemical events that the muropeptides elicit. Muropeptide sensing and recycling in both Gram-positive and Gram-negative bacteria are discussed, followed by muropeptide sensing by eukaryotes as a crucial event in the innate immune response of insects (via peptidoglycan-recognition proteins) and mammals (through Nod-like receptors) to bacterial invasion.
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Affiliation(s)
- Marc A Boudreau
- Department of Chemistry and Biochemistry, Nieuwland Science Hall, University of Notre Dame, Notre Dame, Indiana 46556, USA
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49
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Dhand A, Sakoulas G. Reduced vancomycin susceptibility among clinical Staphylococcus aureus isolates ('the MIC Creep'): implications for therapy. F1000 MEDICINE REPORTS 2012; 4:4. [PMID: 22312414 PMCID: PMC3270590 DOI: 10.3410/m4-4] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Methicillin-resistant S. aureus (MRSA) has emerged as the most common hospital-acquired pathogen and is associated with increased morbidity and mortality compared with other strains. Vancomycin has been the cornerstone of treatment of patients with serious MRSA infections for some decades and while more than 99% of clinical S. aureus isolates remain susceptible to vancomycin, we are beginning to see strains of MRSA with reduced susceptibility. This review discusses this phenomenon, the predictors of infection with such forms of MRSA, and current and future management options.
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Affiliation(s)
- Abhay Dhand
- Department of MedicineNew York Medical College, Valhalla, NY 10595 USA
| | - George Sakoulas
- Department of MedicineNew York Medical College, Valhalla, NY 10595 USA
- Department of Pediatrics, University of California San Diego School of MedicineLa Jolla, CA 92093 USA
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50
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Henriques MX, Rodrigues T, Carido M, Ferreira L, Filipe SR. Synthesis of capsular polysaccharide at the division septum of Streptococcus pneumoniae is dependent on a bacterial tyrosine kinase. Mol Microbiol 2011; 82:515-34. [DOI: 10.1111/j.1365-2958.2011.07828.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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