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George NL, Bennett EC, Orlando BJ. Guarding the walls: the multifaceted roles of Bce modules in cell envelope stress sensing and antimicrobial resistance. J Bacteriol 2024; 206:e0012324. [PMID: 38869304 PMCID: PMC11270860 DOI: 10.1128/jb.00123-24] [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] [Indexed: 06/14/2024] Open
Abstract
Bacteria have developed diverse strategies for defending their cell envelopes from external threats. In Firmicutes, one widespread strategy is to use Bce modules-membrane protein complexes that unite a peptide-detoxifying ABC transporter with a stress response coordinating two-component system. These modules provide specific, front-line defense for a wide variety of antimicrobial peptides and small molecule antibiotics as well as coordinate responses for heat, acid, and oxidative stress. Because of these abilities, Bce modules play important roles in virulence and the development of antibiotic resistance in a variety of pathogens, including Staphylococcus, Streptococcus, and Enterococcus species. Despite their importance, Bce modules are still poorly understood, with scattered functional data in only a small number of species. In this review, we will discuss Bce module structure in light of recent cryo-electron microscopy structures of the B. subtilis BceABRS module and explore the common threads and variations-on-a-theme in Bce module mechanisms across species. We also highlight the many remaining questions about Bce module function. Understanding these multifunctional membrane complexes will enhance our understanding of bacterial stress sensing and may point toward new therapeutic targets for highly resistant pathogens.
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Affiliation(s)
- Natasha L. George
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
- Department of Microbiology, Genetics, and Immunology, Michigan State University, East Lansing, Michigan, USA
| | - Ellen C. Bennett
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
- Department of Microbiology, Genetics, and Immunology, Michigan State University, East Lansing, Michigan, USA
| | - Benjamin J. Orlando
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
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2
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Liu X, de Bakker V, Heggenhougen MV, Mårli MT, Frøynes AH, Salehian Z, Porcellato D, Morales Angeles D, Veening JW, Kjos M. Genome-wide CRISPRi screens for high-throughput fitness quantification and identification of determinants for dalbavancin susceptibility in Staphylococcus aureus. mSystems 2024; 9:e0128923. [PMID: 38837392 PMCID: PMC11265419 DOI: 10.1128/msystems.01289-23] [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: 12/04/2023] [Accepted: 05/01/2024] [Indexed: 06/07/2024] Open
Abstract
Antibiotic resistance and tolerance remain a major problem for the treatment of staphylococcal infections. Identifying genes that influence antibiotic susceptibility could open the door to novel antimicrobial strategies, including targets for new synergistic drug combinations. Here, we developed a genome-wide CRISPR interference library for Staphylococcus aureus, demonstrated its use by quantifying gene fitness in different strains through CRISPRi-seq, and used it to identify genes that modulate susceptibility to the lipoglycopeptide dalbavancin. By exposing the library to sublethal concentrations of dalbavancin using both CRISPRi-seq and direct selection methods, we not only found genes previously reported to be involved in antibiotic susceptibility but also identified genes thus far unknown to affect antibiotic tolerance. Importantly, some of these genes could not have been detected by more conventional transposon-based knockout approaches because they are essential for growth, stressing the complementary value of CRISPRi-based methods. Notably, knockdown of a gene encoding the uncharacterized protein KapB specifically sensitizes the cells to dalbavancin, but not to other antibiotics of the same class, whereas knockdown of the Shikimate pathway showed the opposite effect. The results presented here demonstrate the promise of CRISPRi-seq screens to identify genes and pathways involved in antibiotic susceptibility and pave the way to explore alternative antimicrobial treatments through these insights.IMPORTANCEAntibiotic resistance is a challenge for treating staphylococcal infections. Identifying genes that affect how antibiotics work could help create new treatments. In our study, we made a CRISPR interference library for Staphylococcus aureus and used this to find which genes are critical for growth and also mapped genes that are important for antibiotic sensitivity, focusing on the lipoglycopeptide antibiotic dalbavancin. With this method, we identified genes that altered the sensitivity to dalbavancin upon knockdown, including genes involved in different cellular functions. CRISPRi-seq offers a means to uncover untapped antibiotic targets, including those that conventional screens would disregard due to their essentiality. This paves the way for the discovery of new ways to fight infections.
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Affiliation(s)
- Xue Liu
- Department of Pathogen, Biology, International Cancer Center, Shenzhen University Medical School, Shenzhen, Guangdong, China
- Department of Fundamental Microbiology, University of Lausanne, , Switzerland
| | - Vincent de Bakker
- Department of Fundamental Microbiology, University of Lausanne, , Switzerland
| | | | - Marita Torrissen Mårli
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Norway
| | - Anette Heidal Frøynes
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Norway
| | - Zhian Salehian
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Norway
| | - Davide Porcellato
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Norway
| | - Danae Morales Angeles
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Norway
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, University of Lausanne, , Switzerland
| | - Morten Kjos
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Norway
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3
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Malachowa N, Sturdevant DE, Porter AR, Martin G, Martens C, Nair V, Hansen B, Ricklefs S, Jenkins SG, Chen L, Kreiswirth BN, DeLeo FR. Insights into the molecular basis of reduced vancomycin susceptibility among three prominent Staphylococcus aureus clonal complexes. Microbiol Spectr 2024:e0048624. [PMID: 38916317 DOI: 10.1128/spectrum.00486-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 05/21/2024] [Indexed: 06/26/2024] Open
Abstract
Staphylococcus aureus is a leading cause of healthcare-associated infections globally. Vancomycin-resistant S. aureus (VRSA), those with high-level resistance [minimum inhibitory concentration (MIC) of 16-32 µg/mL vancomycin], are uncommon, whereas vancomycin-intermediate S. aureus (VISA; MIC of 4-8 µg/mL), are isolated more frequently and develop during long-term and/or repeated use of the antibiotic. VISA can be difficult to eradicate and infections may persist. Our knowledge of mechanisms that underlie the development of VISA is incomplete. We used a genomics approach to investigate the VISA phenotype in three prominent S. aureus lineages. All VISA clinical isolates tested had increased cell wall thickness compared with vancomycin-susceptible S. aureus strains. Growth rates of clonal complex (CC) 5, CC8, and CC45 clinical isolates were reduced in 2 µg/mL vancomycin compared to media alone. Culture in 2 and 4 µg/mL vancomycin sequentially for two weeks reduced susceptibility to daptomycin, televancin, tigecycline, and vancomycin in a majority of CC5, CC8, and CC45 isolates tested. We identified alleles reported previously to contribute to the VISA phenotype, but unexpectedly, these alleles were unique to each CC. A subtherapeutic concentration of vancomycin elicited changes in the VISA transcriptome-common and unique-among the three CCs tested. Multiple genes, including those encoding a glycerate kinase, an M50 family metallopeptidase, and an uncharacterized membrane protein, were upregulated among all three lineages and not reported previously as associated with VISA. Although there are lineage-specific changes in DNA sequence, our findings suggest changes in the VISA transcriptome constitute a general response to stress that confers reduced susceptibility to multiple antibiotics. IMPORTANCE Our understanding of the mechanisms that underlie the development of vancomycin-intermediate Staphylococcus aureus (VISA) is incomplete. To provide a more comprehensive view of this process, we compared genome sequences of clonal complex (CC) 5, CC8, and CC45 VISA clinical isolates and measured changes in the transcriptomes of these isolates during culture with a subtherapeutic concentration of vancomycin. Notably, we identified differentially expressed genes that were lineage-specific or common to the lineages tested, including genes that have not been previously reported to contribute to a VISA phenotype. Changes in gene expression were accompanied by reduced growth rate, increased cell wall thickness, and reduced susceptibility to daptomycin, televancin, tigecycline, and vancomycin. Our results provide support to the idea that changes in gene expression contribute to the development of VISA among three CCs that are a prominent cause of human infections.
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Affiliation(s)
- Natalia Malachowa
- Laboratory of Bacteriology, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Daniel E Sturdevant
- Research Technologies Branch, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Adeline R Porter
- Laboratory of Bacteriology, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Grant Martin
- Laboratory of Bacteriology, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Craig Martens
- Research Technologies Branch, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Vinod Nair
- Research Technologies Branch, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Bryan Hansen
- Research Technologies Branch, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Stacy Ricklefs
- Research Technologies Branch, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Stephen G Jenkins
- Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, New York, USA
| | - Liang Chen
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Barry N Kreiswirth
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Frank R DeLeo
- Laboratory of Bacteriology, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
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4
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Fait A, Silva SF, Abrahamsson JÅH, Ingmer H. Staphylococcus aureus response and adaptation to vancomycin. Adv Microb Physiol 2024; 85:201-258. [PMID: 39059821 DOI: 10.1016/bs.ampbs.2024.04.006] [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] [Indexed: 07/28/2024]
Abstract
Antibiotic resistance is an increasing challenge for the human pathogen Staphylococcus aureus. Methicillin-resistant S. aureus (MRSA) clones have spread globally, and a growing number display decreased susceptibility to vancomycin, the favoured antibiotic for treatment of MRSA infections. These vancomycin-intermediate S. aureus (VISA) or heterogeneous vancomycin-intermediate S. aureus (hVISA) strains arise from accumulation of a variety of point mutations, leading to cell wall thickening and reduced vancomycin binding to the cell wall building block, Lipid II, at the septum. They display only minor changes in vancomycin susceptibility, with varying tolerance between cells in a population, and therefore, they can be difficult to detect. In this review, we summarize current knowledge of VISA and hVISA. We discuss the role of genetic strain background or epistasis for VISA development and the possibility of strains being 'transient' VISA with gene expression changes mediated by, for example, VraTSR, GraXSR, or WalRK signal transduction systems, leading to temporary vancomycin tolerance. Additionally, we address collateral susceptibility to other antibiotics than vancomycin. Specifically, we estimate how mutations in rpoB, encoding the β-subunit of the RNA polymerase, affect overall protein structure and compare changes with rifampicin resistance. Ultimately, such in-depth analysis of VISA and hVISA strains in terms of genetic and transcriptional changes, as well as changes in protein structures, may pave the way for improved detection and guide antibiotic therapy by revealing strains at risk of VISA development. Such tools will be valuable for keeping vancomycin an asset also in the future.
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Affiliation(s)
- Anaëlle Fait
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark; Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland
| | - Stephanie Fulaz Silva
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark.
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5
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Liu X, Wang Y, Chang W, Dai Y, Ma X. AgrA directly binds to the promoter of vraSR and downregulates its expression in Staphylococcus aureus. Antimicrob Agents Chemother 2024; 68:e0089323. [PMID: 38259090 PMCID: PMC10916378 DOI: 10.1128/aac.00893-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 12/15/2023] [Indexed: 01/24/2024] Open
Abstract
Staphylococcus aureus is an important human pathogen and vancomycin is widely used for the treatment of S. aureus infections. The global regulator agr is known as a well-described virulence regulator. Previous studies have found that agr-dysfunction strains are more likely to develop into vancomycin-resistant strains, but the mechanism for this phenomenon remains unknown. VraSR is a two-component regulatory system related to vancomycin resistance. In this study, we found that the expression levels of vraR were higher in agr-dysfunction clinical strains than in the agr-functional strains. We knocked out agr in a clinical strain, and quantitative reverse transcription PCR and β-galactosidase activity assays revealed that agr repressed transcription of vraR. After vancomycin exposures, population analysis revealed larger subpopulations displaying reduced susceptibility in agr knockout strain compared with wild-type strain, and this pattern was also observed in agr-dysfunction clinical strains compared with the agr-functional strains. Electrophoretic mobility experiment demonstrated binding of purified AgrA to the promoter region of vraR. In conclusion, our results indicated that the loss of agr function in S. aureus may contribute to the evolution of reduced vancomycin susceptibility through the downregulation of vraSR.
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Affiliation(s)
- Xueer Liu
- Department of Clinical Laboratory, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Yangyan Wang
- Department of Clinical Laboratory, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
| | - Wenjiao Chang
- Department of Clinical Laboratory, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Yuanyuan Dai
- Department of Clinical Laboratory, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Xiaoling Ma
- Department of Clinical Laboratory, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
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6
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Chapman JE, George SE, Wolz C, Olson ME. Biofilms: A developmental niche for vancomycin-intermediate Staphylococcus aureus. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2024; 117:105545. [PMID: 38160879 DOI: 10.1016/j.meegid.2023.105545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/14/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024]
Abstract
Staphylococcus aureus are gram-positive bacteria responsible for a wide array of diseases, ranging from skin and soft tissue infections to more chronic illnesses such as toxic shock syndrome, osteomyelitis, and endocarditis. Vancomycin is currently one of the most effective antibiotics available in treating patients infected with methicillin-resistant S. aureus (MRSA), however the emergence of vancomycin-resistant S. aureus (VRSA), and more commonly vancomycin-intermediate S. aureus (VISA), threaten the future efficacy of vancomycin. Intermediate resistance to vancomycin occurs due to mutations within the loci of Staphylococcal genes involved in cell wall formation such as rpoB, graS, and yycG. We hypothesized the VISA phenotype may also arise as a result of the natural stress occurring within S. aureus biofilms, and that this phenomenon is mediated by the RecA/SOS response. Wildtype and recA null mutant/lexAG94E strains of S. aureus biofilms were established in biofilm microtiter assays or planktonic cultures with or without the addition of sub-inhibitory concentrations of vancomycin (0.063 mg/l - 0.25 mg/L ciprofloxacin, 0.5 mg/l vancomycin). Efficiency of plating techniques were used to quantify the subpopulation of biofilm-derived S. aureus cells that developed vancomycin-intermediate resistance. The results indicated that a greater subpopulation of cells from wildtype biofilms (4.16 × 102 CFUs) emerged from intermediate-resistant concentrations of vancomycin (4 μg/ml) compared with the planktonic counterpart (1.53 × 101 CFUs). Wildtype biofilms (4.16 × 102 CFUs) also exhibited greater resistance to intermediate-resistant concentrations of vancomycin compared with strains deficient in the recA null mutant (8.15 × 101 CFUs) and lexA genes (8.00 × 101 CFUs). While the VISA phenotype would be an unintended consequence of genetic diversity and potentially gene transfer in the biofilm setting, it demonstrates that mutations occurring within biofilms allow for S. aureus to adapt to new environments, including the presence of widely used antibiotics.
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Affiliation(s)
- Jenelle E Chapman
- Department of Medical Microbiology, Immunology, and Cell Biology, Southern Illinois University School of Medicine, USA
| | - Shilpa E George
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Germany
| | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Germany
| | - Michael E Olson
- Department of Medical Microbiology, Immunology, and Cell Biology, Southern Illinois University School of Medicine, USA.
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7
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Jiang JH, Cameron DR, Nethercott C, Aires-de-Sousa M, Peleg AY. Virulence attributes of successful methicillin-resistant Staphylococcus aureus lineages. Clin Microbiol Rev 2023; 36:e0014822. [PMID: 37982596 PMCID: PMC10732075 DOI: 10.1128/cmr.00148-22] [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] [Indexed: 11/21/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of severe and often fatal infections. MRSA epidemics have occurred in waves, whereby a previously successful lineage has been replaced by a more fit and better adapted lineage. Selection pressures in both hospital and community settings are not uniform across the globe, which has resulted in geographically distinct epidemiology. This review focuses on the mechanisms that trigger the establishment and maintenance of current, dominant MRSA lineages across the globe. While the important role of antibiotic resistance will be mentioned throughout, factors which influence the capacity of S. aureus to colonize and cause disease within a host will be the primary focus of this review. We show that while MRSA possesses a diverse arsenal of toxins including alpha-toxin, the success of a lineage involves more than just producing toxins that damage the host. Success is often attributed to the acquisition or loss of genetic elements involved in colonization and niche adaptation such as the arginine catabolic mobile element, as well as the activity of regulatory systems, and shift metabolism accordingly (e.g., the accessory genome regulator, agr). Understanding exactly how specific MRSA clones cause prolonged epidemics may reveal targets for therapies, whereby both core (e.g., the alpha toxin) and acquired virulence factors (e.g., the Panton-Valentine leukocidin) may be nullified using anti-virulence strategies.
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Affiliation(s)
- Jhih-Hang Jiang
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - David R. Cameron
- Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Cara Nethercott
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Marta Aires-de-Sousa
- Laboratory of Molecular Genetics, Institutode Tecnologia Químicae Biológica António Xavier (ITQB-NOVA), Universidade Nova de Lisboa, Oeiras, Portugal
- Escola Superior de Saúde da Cruz Vermelha Portuguesa-Lisboa (ESSCVP-Lisboa), Lisbon, Portugal
| | - Anton Y. Peleg
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Centre to Impact Antimicrobial Resistance, Monash University, Clayton, Melbourne, Victoria, Australia
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8
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Fait A, Andersson DI, Ingmer H. Evolutionary history of Staphylococcus aureus influences antibiotic resistance evolution. Curr Biol 2023; 33:3389-3397.e5. [PMID: 37494936 DOI: 10.1016/j.cub.2023.06.082] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 05/05/2023] [Accepted: 06/29/2023] [Indexed: 07/28/2023]
Abstract
Antibiotic resistance often confers a fitness cost to the resistant cell and thus raises key questions of how resistance is maintained in the absence of antibiotics and, if lost, whether cells are genetically primed for re-evolving resistance. To address these questions, we have examined vancomycin-intermediate Staphylococcus aureus (VISA) strains that arise during vancomycin therapy. VISA strains harbor a broad spectrum of mutations, and they are known to be unstable both in patients and in the laboratory. Here, we show that loss of resistance in VISA strains is correlated with a fitness increase and is attributed to adaptive mutations, leaving the initial VISA-adaptive mutations intact. Importantly, upon a second exposure to vancomycin, such revertants evolve significantly faster to become VISA, and they reach higher resistance levels than vancomycin-naive cells. Further, we find that sub-lethal concentrations of vancomycin stabilize the VISA phenotype, as do the human β-defensin 3 (hBD-3) and the bacteriocin nisin that both, like vancomycin, bind to the peptidoglycan building block, lipid II. Thus, factors binding lipid II may stabilize VISA both in vivo and in vitro, and in case resistance is lost, mutations remain that predispose to resistance development. These findings may explain why VISA infections often are re-occurring and suggest that previous vancomycin adaptation should be considered a risk factor when deciding on antimicrobial chemotherapy.
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Affiliation(s)
- Anaëlle Fait
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland
| | - Dan I Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, 751 23 Uppsala, Sweden
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark.
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9
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Xu L, Henriksen C, Mebus V, Guérillot R, Petersen A, Jacques N, Jiang JH, Derks RJE, Sánchez-López E, Giera M, Leeten K, Stinear TP, Oury C, Howden BP, Peleg AY, Frees D. A Clinically Selected Staphylococcus aureus clpP Mutant Survives Daptomycin Treatment by Reducing Binding of the Antibiotic and Adapting a Rod-Shaped Morphology. Antimicrob Agents Chemother 2023; 67:e0032823. [PMID: 37184389 PMCID: PMC10269151 DOI: 10.1128/aac.00328-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 04/10/2023] [Indexed: 05/16/2023] Open
Abstract
Daptomycin is a last-resort antibiotic used for the treatment of infections caused by Gram-positive antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA). Treatment failure is commonly linked to accumulation of point mutations; however, the contribution of single mutations to resistance and the mechanisms underlying resistance remain incompletely understood. Here, we show that a single nucleotide polymorphism (SNP) selected during daptomycin therapy inactivates the highly conserved ClpP protease and is causing reduced susceptibility of MRSA to daptomycin, vancomycin, and β-lactam antibiotics as well as decreased expression of virulence factors. Super-resolution microscopy demonstrated that inactivation of ClpP reduced binding of daptomycin to the septal site and diminished membrane damage. In both the parental strain and the clpP strain, daptomycin inhibited the inward progression of septum synthesis, eventually leading to lysis and death of the parental strain while surviving clpP cells were able to continue synthesis of the peripheral cell wall in the presence of 10× MIC daptomycin, resulting in a rod-shaped morphology. To our knowledge, this is the first demonstration that synthesis of the outer cell wall continues in the presence of daptomycin. Collectively, our data provide novel insight into the mechanisms behind bacterial killing and resistance to this important antibiotic. Also, the study emphasizes that treatment with last-line antibiotics is selective for mutations that, like the SNP in clpP, favor antibiotic resistance over virulence gene expression.
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Affiliation(s)
- Lijuan Xu
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Camilla Henriksen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Viktor Mebus
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Romain Guérillot
- Department of Microbiology and Immunology, University of Melbourne at the Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | | | - Nicolas Jacques
- Laboratory of Cardiology, GIGA Institute, University of Liège Hospital, Liège, Belgium
| | - Jhih-Hang Jiang
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
- Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Rico J. E. Derks
- Leiden University Medical Center, Center for Proteomics and Metabolomics, Leiden, Netherlands
| | - Elena Sánchez-López
- Leiden University Medical Center, Center for Proteomics and Metabolomics, Leiden, Netherlands
| | - Martin Giera
- Leiden University Medical Center, Center for Proteomics and Metabolomics, Leiden, Netherlands
| | - Kirsten Leeten
- Laboratory of Cardiology, GIGA Institute, University of Liège Hospital, Liège, Belgium
| | - Timothy P. Stinear
- Department of Microbiology and Immunology, University of Melbourne at the Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Cécile Oury
- Laboratory of Cardiology, GIGA Institute, University of Liège Hospital, Liège, Belgium
| | - Benjamin P. Howden
- Department of Microbiology and Immunology, University of Melbourne at the Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Anton Y. Peleg
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
- Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Dorte Frees
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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10
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Dong W, Peng Q, Tang X, Zhong T, Lin S, Zhi Z, Ye J, Yang B, Sun N, Yuan W. Identification and Characterization of a Vancomycin Intermediate-Resistant Staphylococcus haemolyticus Isolated from Guangzhou, China. Infect Drug Resist 2023; 16:3639-3647. [PMID: 37313263 PMCID: PMC10259589 DOI: 10.2147/idr.s411860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/02/2023] [Indexed: 06/15/2023] Open
Abstract
Background Staphylococcus haemolyticus is an opportunistic pathogen that belongs to coagulase-negative Staphylococci (CoNS). Increasing infection and multi-drug resistance cases caused by this strain have been reported and thus it poses a great health threat. Methods The third-generation sequencing technology was performed on a S. haemolyticus SH-1 isolated from a clinical sample to analyze the drug resistance genes, which included vancomycin resistance related genes. In addition, antimicrobial susceptibility tests, transmission electron microscopy and Triton X-100 stimulated autolysis were conducted to understand its biological characteristics. Results The study shows that this clinical isolate is a vancomycin intermediate-resistant strain. Genome comparison also revealed that WalK(N70K) and WalK(R280Q) mutations may contribute to the vancomycin resistant phenotype. Besides, S. haemolyticus SH-1 exhibit common features of thicker cell wall and decreased autolytic activity. Conclusion S. haemolyticus SH-1 with WalKR mutations shows typical characteristics of vancomycin resistant strains. Combining the genome features and biological properties, our findings may provide important information for the understanding of the molecular mechanism of S. haemolyticus to vancomycin intermediate-resistance.
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Affiliation(s)
- Wanyang Dong
- Guangzhou Key Laboratory for Clinical Rapid Diagnosis and Early Warning of Infectious Diseases, KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, 510180, People’s Republic of China
| | - Qi Peng
- Guangzhou Key Laboratory for Clinical Rapid Diagnosis and Early Warning of Infectious Diseases, KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, 510180, People’s Republic of China
| | - Xiaohua Tang
- Guangzhou Key Laboratory for Clinical Rapid Diagnosis and Early Warning of Infectious Diseases, KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, 510180, People’s Republic of China
- Third Affiliated Hospital of Guangzhou Medical University, Department of Clinical Laboratory, Guangzhou, 510150, People’s Republic of China
| | - Tian Zhong
- Guangzhou Key Laboratory for Clinical Rapid Diagnosis and Early Warning of Infectious Diseases, KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, 510180, People’s Republic of China
| | - Shunan Lin
- Guangzhou Key Laboratory for Clinical Rapid Diagnosis and Early Warning of Infectious Diseases, KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, 510180, People’s Republic of China
| | - Ziling Zhi
- Guangzhou Key Laboratory for Clinical Rapid Diagnosis and Early Warning of Infectious Diseases, KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, 510180, People’s Republic of China
| | - Jingyi Ye
- Guangzhou Key Laboratory for Clinical Rapid Diagnosis and Early Warning of Infectious Diseases, KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, 510180, People’s Republic of China
| | - Bixia Yang
- Guangzhou Key Laboratory for Clinical Rapid Diagnosis and Early Warning of Infectious Diseases, KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, 510180, People’s Republic of China
| | - Ning Sun
- Guangzhou Key Laboratory for Clinical Rapid Diagnosis and Early Warning of Infectious Diseases, KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, 510180, People’s Republic of China
- Guangzhou First People’s Hospital, School of Medicine, South China University of Technology, Guangzhou, 510180, People’s Republic of China
| | - Wenchang Yuan
- Guangzhou Key Laboratory for Clinical Rapid Diagnosis and Early Warning of Infectious Diseases, KingMed School of Laboratory Medicine, Guangzhou Medical University, Guangzhou, 510180, People’s Republic of China
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11
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Ejaz M, Syed MA, Jackson CR, Sharif M, Faryal R. Epidemiology of Staphylococcus aureus Non-Susceptible to Vancomycin in South Asia. Antibiotics (Basel) 2023; 12:972. [PMID: 37370291 DOI: 10.3390/antibiotics12060972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/19/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
Staphylococcus aureus is one of the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens among which multidrug resistance has emerged. Resistance to methicillin has resulted in clinicians using the antibiotic of last resort, vancomycin, to treat infections caused by methicillin-resistant S. aureus (MRSA). However, excessive use and misuse of vancomycin are major causes of resistance among S. aureus strains. South Asia encompasses ~25% of the world's population, and countries in South Asia are often characterized as low- and middle-income with poor healthcare infrastructure that may contribute to the emergence of antibiotic resistance. Here, we briefly highlight the mechanism of vancomycin resistance, its emergence in S. aureus, and the molecular epidemiology of non-susceptible S. aureus to vancomycin in the South Asian region.
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Affiliation(s)
- Mohammad Ejaz
- Department of Microbiology, Government Postgraduate College Mandian Abbottabad, Abbottabad 22044, Pakistan
- Department of Microbiology, Qauid-i-Azam University, Islamabad 45320, Pakistan
| | - Muhammad Ali Syed
- Department of Microbiology, The University of Haripur, Haripur 22620, Pakistan
| | - Charlene R Jackson
- U.S. Department of Agriculture, Agricultural Research Service, U.S. National Poultry Research Center, Poultry Microbiological Safety and Processing Unit, Athens, GA 30605, USA
| | - Mehmoona Sharif
- Department of Microbiology, Qauid-i-Azam University, Islamabad 45320, Pakistan
| | - Rani Faryal
- Department of Microbiology, Qauid-i-Azam University, Islamabad 45320, Pakistan
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Poshvina DV, Dilbaryan DS, Vasilchenko AS. Gausemycin A-Resistant Staphylococcus aureus Demonstrates Affected Cell Membrane and Cell Wall Homeostasis. Microorganisms 2023; 11:1330. [PMID: 37317304 DOI: 10.3390/microorganisms11051330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 05/16/2023] [Accepted: 05/17/2023] [Indexed: 06/16/2023] Open
Abstract
Antibiotic resistance is a significant and pressing issue in the medical field, as numerous strains of infectious bacteria have become resistant to commonly prescribed antibiotics. Staphylococcus aureus is a bacterium that poses a grave threat, as it is responsible for a large number of nosocomial infections and has high mortality rates worldwide. Gausemycin A is a new lipoglycopeptide antibiotic that has considerable efficacy against multidrug-resistant S. aureus strains. Although the cellular targets of gausemycin A have been previously identified, detailing the molecular processes of action is still needed. We performed gene expression analysis to identify molecular mechanisms that may be involved in bacterial resistance to gausemycin A. In the present study, we observed that gausemycin A-resistant S. aureus in the late-exponential phase showed an increased expression of genes involved in cell wall turnover (sceD), membrane charge (dltA), phospholipid metabolism (pgsA), the two-component stress-response system (vraS), and the Clp proteolytic system (clpX). The increased expression of these genes implies that changes in the cell wall and cell membrane are essential for the bacterial resistance to gausemycin A. In the stationary phase, we observed a decrease in the expression of genes involved in the phospholipid metabolism (mprF) and Clp proteolytic system (clpX).
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Affiliation(s)
- Darya V Poshvina
- Laboratory of Antimicrobial Resistance, Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, 625003 Tyumen, Russia
| | - Diana S Dilbaryan
- Laboratory of Antimicrobial Resistance, Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, 625003 Tyumen, Russia
| | - Alexey S Vasilchenko
- Laboratory of Antimicrobial Resistance, Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, 625003 Tyumen, Russia
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13
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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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Thomas P, Deming MA, Sarkar A. β-Lactamase Suppression as a Strategy to Target Methicillin-Resistant Staphylococcus aureus: Proof of Concept. ACS OMEGA 2022; 7:46213-46221. [PMID: 36570253 PMCID: PMC9773349 DOI: 10.1021/acsomega.2c04381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 11/21/2022] [Indexed: 06/17/2023]
Abstract
β-Lactamase (penicillinase) renders early, natural β-lactams like penicillin G useless against methicillin-resistant Staphylococcus aureus (MRSA), which also expresses PBP2a, responsible for resistance to semisynthetic, penicillinase-insensitive β-lactams like oxacillin. Antimicrobial discovery is difficult, and resistance exists against most treatment options. Enhancing β-lactams against MRSA would revive its clinical utility. Most research on antimicrobial enhancement against MRSA focuses on oxacillin due to β-lactamase expression. Yet, Moreillon and others have demonstrated that penicillin G is as potent against a β-lactamase gene knockout strain, as vancomycin is against wild-type MRSA. Penicillin G overcame PBP2a because β-lactamase activity was blocked. Additionally, animals treated with a combination of direct β-lactamase inhibitors like sulbactam and clavulanate with penicillin G developed resistant infections, clearly demonstrating that direct inhibition of β-lactamase is not a good strategy. Here, we show that 50 μM pyrimidine-2-amines (P2As) reduce the minimum inhibitory concentration (MIC) of penicillin G against MRSA strains by up to 16-fold by reducing β-lactamase activity but not by direct inhibition of the enzyme. Oxacillin was not enhanced due to PBP2a expression, demonstrating the advantage of penicillin G over penicillinase-insensitive β-lactams. P2As modulate an unknown global regulator but not established antimicrobial-enhancement targets Stk1 and VraS. P2As are a practical implementation of Moreillon's principle of suppressing β-lactamase activity to make penicillin G useful against MRSA, without employing direct enzyme inhibitors.
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Rao Y, Peng H, Shang W, Hu Z, Yang Y, Tan L, Li M, Zhou R, Rao X. A vancomycin resistance-associated WalK(S221P) mutation attenuates the virulence of vancomycin-intermediate Staphylococcus aureus. J Adv Res 2022; 40:167-178. [PMID: 36100324 PMCID: PMC9481939 DOI: 10.1016/j.jare.2021.11.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 11/25/2022] Open
Abstract
INTRODUCTION Vancomycin-intermediate Staphylococcus aureus (VISA) is typically associated with a decline in virulence. We previously reported a WalK(S221P) mutation that plays an important role in mediating vancomycin resistance in VISA XN108. Whether this mutation is implicated in bacterial virulence remains unknown. OBJECTIVES This study aimed to investigate the effect of WalK(S221P) mutation on the virulence of VISA and the underlying mechanism of this effect. METHODS The influence of WalK(S221P) mutation on VISA virulence and its underlying mechanism were explored using animal models, RNA-seq analysis, RT-qPCR, hemolytic assay, slide coagulase test, Western blot, β-galactosidase assay, and electrophoresis mobility shift assay (EMSA). RESULTS Compared with XN108, WalK(S221P)-reverted strain XN108-R exacerbated cutaneous infections with increased lesion size and extensive inflammatory infiltration in mouse models. The bacterial loads of S. aureus XN108-R in murine kidney increased compared with those of XN108. RNA-seq analysis showed upregulation of a set of virulence genes in XN108-R, which exhibited greater hemolytic and stronger coagulase activities compared with XN108. Introduction of WalK(S221P) to methicillin-resistant S. aureus USA300 and methicillin-susceptible strain Newman increased the vancomycin resistance of the mutants, which exhibited reduced hemolytic activities and decreased expression levels of many virulence factors compared with their progenitors. WalK(S221P) mutation weakened agr promoter-controlled β-galactosidase activity. EMSA results showed that WalK-phosphorylated WalR could directly bind to the agr promoter region, whereas WalK(S221P)-activated WalR reduced binding to the target promoter. Inactivation of agr in S. aureus did not affect their vancomycin susceptibility but mitigated the virulence alterations caused by WalK(S221P) mutation. CONCLUSION The results of our study indicate that WalK(S221P) mutation can enhance vancomycin resistance in S. aureus of diverse genetic backgrounds. WalK(S221P)- bearing S. aureus strains exhibit reduced virulence. WalK(S221P) mutation may directly impair the activation of the agr system by WalR, thereby decreasing the expression of virulence factors in VISA.
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Affiliation(s)
- Yifan Rao
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University (Third Military Medical University), Chongqing 400038, China; Department of Emergency Medicine, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing 400037, China
| | - Huagang Peng
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Weilong Shang
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Zhen Hu
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Yi Yang
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Li Tan
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Ming Li
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University (Third Military Medical University), Chongqing 400038, China.
| | - Renjie Zhou
- Department of Emergency Medicine, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing 400037, China.
| | - Xiancai Rao
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University (Third Military Medical University), Chongqing 400038, China.
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Rosenbergová Z, Oftedal TF, Ovchinnikov KV, Thiyagarajah T, Rebroš M, Diep DB. Identification of a Novel Two-Peptide Lantibiotic from Vagococcus fluvialis. Microbiol Spectr 2022; 10:e0095422. [PMID: 35730941 PMCID: PMC9431498 DOI: 10.1128/spectrum.00954-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 05/24/2022] [Indexed: 11/20/2022] Open
Abstract
Infections caused by multiresistant pathogens have become a major problem in both human and veterinary medicine. Due to the declining efficacy of many antibiotics, new antimicrobials are needed. Promising alternatives or additions to antibiotics are bacteriocins, antimicrobial peptides of bacterial origin with activity against many pathogens, including antibiotic-resistant strains. From a sample of fermented maize, we isolated a Vagococcus fluvialis strain producing a bacteriocin with antimicrobial activity against multiresistant Enterococcus faecium. Whole-genome sequencing revealed the genes for a novel two-peptide lantibiotic. The production of the lantibiotic by the isolate was confirmed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, which revealed distinct peaks at 4,009.4 m/z and 3,181.7 m/z in separate fractions from reversed-phase chromatography. The combination of the two peptides resulted in a 1,200-fold increase in potency, confirming the two-peptide nature of the bacteriocin, named vagococcin T. The bacteriocin was demonstrated to kill sensitive cells by the formation of pores in the cell membrane, and its inhibition spectrum covers most Gram-positive bacteria, including multiresistant pathogens. To our knowledge, this is the first bacteriocin characterized from Vagococcus. IMPORTANCE Enterococci are common commensals in the intestines of humans and animals, but in recent years, they have been identified as one of the major causes of hospital-acquired infections due to their ability to quickly acquire virulence and antibiotic resistance determinants. Many hospital isolates are multiresistant, thereby making current therapeutic options critically limited. Novel antimicrobials or alternative therapeutic approaches are needed to overcome this global problem. Bacteriocins, natural ribosomally synthesized peptides produced by bacteria to eliminate other bacterial species living in a competitive environment, provide such an alternative. In this work, we purified and characterized a novel two-peptide lantibiotic produced by Vagococcus fluvialis LMGT 4216 isolated from fermented maize. The novel lantibiotic showed a broad spectrum of inhibition of Gram-positive strains, including vancomycin-resistant Enterococcus faecium, demonstrating its therapeutic potential.
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Affiliation(s)
- Zuzana Rosenbergová
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
- Institute of Biotechnology, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovakia
| | - Thomas F. Oftedal
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Kirill V. Ovchinnikov
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Thasanth Thiyagarajah
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Martin Rebroš
- Institute of Biotechnology, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovakia
| | - Dzung B. Diep
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
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Yuan Z, Gottsacker C, He X, Waterkotte T, Park YC. Repetitive drug delivery using Light-Activated liposomes for potential antimicrobial therapies. Adv Drug Deliv Rev 2022; 187:114395. [DOI: 10.1016/j.addr.2022.114395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 05/15/2022] [Accepted: 06/08/2022] [Indexed: 12/22/2022]
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Adaptive laboratory evolution and independent component analysis disentangle complex vancomycin adaptation trajectories. Proc Natl Acad Sci U S A 2022; 119:e2118262119. [PMID: 35858453 PMCID: PMC9335240 DOI: 10.1073/pnas.2118262119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Infections with methicillin-resistant Staphylococcus aureus (MRSA) are associated with significant morbidity and mortality. Vancomycin is a last-line antibiotic used to treat MRSA infections; however, strains with decreased susceptibility to vancomycin (vancomycin-intermediate S. aureus [VISA]) have been spreading, and VISA infections are associated with prolonged therapeutic treatment and treatment failure. To map out the evolutionary trajectory behind VISA development, we characterized the mutational, transcriptional, and phenotypic landscape of 10 lineages of S. aureus USA300 strain JE2 that evolved in parallel to vancomycin. We demonstrate that MRSA strains adapt to vancomycin by divergent pathways leading to high or low oxacillin susceptibility characterized by mutational or transcriptional profiles. Our results point to diagnostic possibilities that may support personalized antibiotic treatment regimes. Human infections with methicillin-resistant Staphylococcus aureus (MRSA) are commonly treated with vancomycin, and strains with decreased susceptibility, designated as vancomycin-intermediate S. aureus (VISA), are associated with treatment failure. Here, we profiled the phenotypic, mutational, and transcriptional landscape of 10 VISA strains adapted by laboratory evolution from one common MRSA ancestor, the USA300 strain JE2. Using functional and independent component analysis, we found that: 1) despite the common genetic background and environmental conditions, the mutational landscape diverged between evolved strains and included mutations previously associated with vancomycin resistance (in vraT, graS, vraFG, walKR, and rpoBCD) as well as novel adaptive mutations (SAUSA300_RS04225, ssaA, pitAR, and sagB); 2) the first wave of mutations affected transcriptional regulators and the second affected genes involved in membrane biosynthesis; 3) expression profiles were predominantly strain-specific except for sceD and lukG, which were the only two genes significantly differentially expressed in all clones; 4) three independent virulence systems (φSa3, SaeR, and T7SS) featured as the most transcriptionally perturbed gene sets across clones; 5) there was a striking variation in oxacillin susceptibility across the evolved lineages (from a 10-fold increase to a 63-fold decrease) that also arose in clinical MRSA isolates exposed to vancomycin and correlated with susceptibility to teichoic acid inhibitors; and 6) constitutive expression of the VraR regulon explained cross-susceptibility, while mutations in walK were associated with cross-resistance. Our results show that adaptation to vancomycin involves a surprising breadth of mutational and transcriptional pathways that affect antibiotic susceptibility and possibly the clinical outcome of infections.
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Baseri N, Najar-Peerayeh S, Bakhshi B, Campanile F. Phenotypic and genotypic changes of Staphylococcus aureus in the presence of the inappropriate concentration of chlorhexidine gluconate. BMC Microbiol 2022; 22:100. [PMID: 35418037 PMCID: PMC9006606 DOI: 10.1186/s12866-022-02522-0] [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] [Received: 02/06/2022] [Accepted: 04/06/2022] [Indexed: 11/10/2022] Open
Abstract
Background Chlorhexidine gluconate (CHG) is a disinfectant agent with different applications in health care. Improper use of CHG causes antimicrobial resistance in bacteria as a public health threat. Since Staphylococcus aureus is a common bacteria, it is expected usually exposed to CHG in the hospital and community. The present study aimed to correlate the phenotypic and genotypic changes in a S. aureus strain upon serial adaptation with supra-inhibitory CHG concentration for 50 days. Results After in vitro serial culture of 5 × 105 CFU/ml of a clinical vancomycin-susceptible S. aureus strain (VAN-S) into brain heart infusion (BHI) broth containing CHG 1/4, 1/2, 1, and 2 × minimal inhibitory concentration (MIC) values of VAN-S in 37 °C during 50 days, we isolated a S. aureus strain (CHGVan-I) with a ≥ twofold decrease in susceptibility to CHG and vancomycin. CHG-induced CHGVan-I strain was considered as a vancomycin-intermediate S. aureus (VISA) strain with a VAN MIC of 4 μg/ml using the broth macro dilution method. However, reduced resistance was observed to tetracycline family antibiotics (doxycycline and tetracycline) using a modified Kirby-Bauer disk diffusion test. Moreover, a remarkable reduction was detected in growth rate, hemolysis activity (the lysis of human red blood cells by alpha-hemolysin), and colony pigmentation (on BHI agar plates). Biofilm formation (using the Microtiter plate method and crystal violet staining) was significantly increased upon CHG treatment. Adaptive changes in the expression of a set of common genes related to the development of VISA phenotype (graTSR, vraTSR, walKR, agr RNAIII, sceD, pbpB, and fmtA) were analyzed by Reverse Transcription quantitative PCR (RT-qPCR) experiment. Significant changes in vraTSR, agr RNAIII, sceD, and pbpB expression were observed. However, gene sequencing of the two-component system vraTSR using the Sanger sequencing method did not detect any non-synonymous substitution in CHGVan-I compared to wild-type. The clonality of VAN-S and CHGVan-I strains was verified using the pulsed-field gel electrophoresis (PFGE) method. Conclusions The importance of the present study should be stated in new detected mechanisms underlying VISA development. We found a link between the improper CHX use and the development of phenotypic and genotypic features, typical of VISA clinical isolates, in a CHG-induced strain. Since disruption of the cell wall biosynthesis occurs in VISA isolates, our CHG-induced VISA strain proved new insights into the role of CHG in the stimulation of the S. aureus cell wall.
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Affiliation(s)
- Neda Baseri
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Shahin Najar-Peerayeh
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Bita Bakhshi
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Floriana Campanile
- Department of Biomedical and Biotechnological Sciences (BIOMETEC), Medical Molecular Microbiology and Antibiotic Resistance Laboratory (MMARLab), University of Catania, Catania, Italy
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20
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Baseri N, Najar-Peerayeh S, Bakhshi B. Investigating the effect of an identified mutation within a critical site of PAS domain of WalK protein in a vancomycin-intermediate resistant Staphylococcus aureus by computational approaches. BMC Microbiol 2021; 21:240. [PMID: 34474665 PMCID: PMC8414773 DOI: 10.1186/s12866-021-02298-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 08/23/2021] [Indexed: 11/15/2022] Open
Abstract
Background Vancomycin-intermediate resistant Staphylococcus aureus (VISA) is becoming a common cause of nosocomial infections worldwide. VISA isolates are developed by unclear molecular mechanisms via mutations in several genes, including walKR. Although studies have verified some of these mutations, there are a few studies that pay attention to the importance of molecular modelling of mutations. Method For genomic and transcriptomic comparisons in a laboratory-derived VISA strain and its parental strain, Sanger sequencing and reverse transcriptase quantitative PCR (RT-qPCR) methods were used, respectively. After structural protein mapping of the detected mutation, mutation effects were analyzed using molecular computational approaches and crystal structures of related proteins. Results A mutation WalK-H364R was occurred in a functional zinc ion coordinating residue within the PAS domain in the VISA strain. WalK-H364R was predicted to destabilize protein and decrease WalK interactions with proteins and nucleic acids. The RT-qPCR method showed downregulation of walKR, WalKR-regulated autolysins, and agr locus. Conclusion Overall, WalK-H364R mutation within a critical metal-coordinating site was presumably related to the VISA development. We assume that the WalK-H364R mutation resulted in deleterious effects on protein, which was verified by walKR gene expression changes.. Therefore, molecular modelling provides detailed insight into the molecular mechanism of VISA development, in particular, where allelic replacement experiments are not readily available. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02298-9.
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Affiliation(s)
- Neda Baseri
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Shahin Najar-Peerayeh
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Bita Bakhshi
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
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21
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Environmental conditions dictate differential evolution of vancomycin resistance in Staphylococcus aureus. Commun Biol 2021; 4:793. [PMID: 34172889 PMCID: PMC8233327 DOI: 10.1038/s42003-021-02339-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 06/09/2021] [Indexed: 02/06/2023] Open
Abstract
While microbiological resistance to vancomycin in Staphylococcus aureus is rare, clinical vancomycin treatment failures are common, and methicillin-resistant S. aureus (MRSA) strains isolated from patients after prolonged vancomycin treatment failure remain susceptible. Adaptive laboratory evolution was utilized to uncover mutational mechanisms associated with MRSA vancomycin resistance in a physiological medium as well as a bacteriological medium used in clinical susceptibility testing. Sequencing of resistant clones revealed shared and media-specific mutational outcomes, with an overlap in cell wall regulons (walKRyycHI, vraSRT). Evolved strains displayed similar properties to resistant clinical isolates in their genetic and phenotypic traits. Importantly, resistant phenotypes that developed in physiological media did not translate into resistance in bacteriological media. Further, a bacteriological media-specific mechanism for vancomycin resistance associated with a mutated mprF was confirmed. This study bridges the gap between the understanding of clinical and microbiological vancomycin resistance in S. aureus and expands the number of allelic variants (18 ± 4 mutations for the top 5 mutated genes) that result in vancomycin resistance phenotypes.
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Hines KM, Shen T, Ashford NK, Waalkes A, Penewit K, Holmes EA, McLean K, Salipante SJ, Werth BJ, Xu L. Occurrence of cross-resistance and β-lactam seesaw effect in glycopeptide-, lipopeptide- and lipoglycopeptide-resistant MRSA correlates with membrane phosphatidylglycerol levels. J Antimicrob Chemother 2021; 75:1182-1186. [PMID: 32016379 DOI: 10.1093/jac/dkz562] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 11/14/2019] [Accepted: 12/16/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Glycopeptides (GPs), lipopeptides (LPs) and lipoglycopeptides (LGPs) are related antimicrobials important for the management of invasive MRSA infections. Cross-resistance among these antibiotics in MRSA is well documented, as is the observation that susceptibility of MRSA to β-lactams increases as susceptibility to GPs and LPs decreases (i.e. the seesaw effect). Efforts to understand the relationship between GP/LP/LGP cross-resistance and the seesaw effect have focused on the PBPs, but the role of lipid metabolism has not been investigated. OBJECTIVES Since the cell membrane is structurally and metabolically integrated with the cell wall and anchors associated proteins, including PBPs, we examined the relationship between membrane lipid composition and the phenomena of cross-resistance among GPs/LPs/LGPs and the β-lactam seesaw effect. METHODS We selected for daptomycin, vancomycin and dalbavancin resistance using the USA300 strain JE2 and evaluated the resulting mutants by WGS, MS-based lipidomics and antimicrobial susceptibility testing to assess the relationship between membrane composition, cross-resistance, and the seesaw effect. RESULTS We observed cross-resistance to GPs/LPs/LGPs among the selected strains and the seesaw effect against various β-lactams, depending on the PBP targets of the particular β-lactam. We found that modification of membrane composition occurs not only in daptomycin-selected strains, but also vancomycin- and dalbavancin-selected strains. Significantly, we observed that the abundance of most phosphatidylglycerols positively correlates with MICs of GPs/LPs/LGPs and negatively correlates with the MICs of β-lactams. CONCLUSIONS These studies demonstrate a major association between membrane remodelling, cross-resistance and the seesaw effect.
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Affiliation(s)
- Kelly M Hines
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | - Tianwei Shen
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | | | - Adam Waalkes
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA
| | - Kelsi Penewit
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA
| | - Elizabeth A Holmes
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA
| | - Kathryn McLean
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA
| | - Stephen J Salipante
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA
| | - Brian J Werth
- Department of Pharmacy, University of Washington, Seattle, WA, USA
| | - Libin Xu
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
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23
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Mat Rani NNI, Mustafa Hussein Z, Mustapa F, Azhari H, Sekar M, Chen XY, Mohd Amin MCI. Exploring the possible targeting strategies of liposomes against methicillin-resistant Staphylococcus aureus (MRSA). Eur J Pharm Biopharm 2021; 165:84-105. [PMID: 33974973 DOI: 10.1016/j.ejpb.2021.04.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 03/26/2021] [Accepted: 04/26/2021] [Indexed: 12/12/2022]
Abstract
Multi antibiotic-resistant bacterial infections are on the rise due to the overuse of antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the pathogens listed under the category of serious threats where vancomycin remains the mainstay treatment despite the availability of various antibacterial agents. Recently, decreased susceptibility to vancomycin from clinical isolates of MRSA has been reported and has drawn worldwide attention as it is often difficult to overcome and leads to increased medical costs, mortality, and longer hospital stays. Development of antibiotic delivery systems is often necessary to improve bioavailability and biodistribution, in order to reduce antibiotic resistance and increase the lifespan of antibiotics. Liposome entrapment has been used as a method to allow higher drug dosing apart from reducing toxicity associated with drugs. The surface of the liposomes can also be designed and enhanced with drug-release properties, active targeting, and stealth effects to prevent recognition by the mononuclear phagocyte system, thus enhancing its circulation time. The present review aimed to highlight the possible targeting strategies of liposomes against MRSA bacteremia systemically while investigating the magnitude of this effect on the minimum inhibitory concentration level.
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Affiliation(s)
- Nur Najihah Izzati Mat Rani
- Centre for Drug Delivery Technology, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia; Faculty of Pharmacy and Health Sciences, Universiti Kuala Lumpur Royal College of Medicine Perak, 30450 Ipoh, Perak, Malaysia
| | - Zahraa Mustafa Hussein
- Centre for Drug Delivery Technology, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia
| | - Fahimi Mustapa
- Hospital Batu Gajah Jalan Changkat, 31000 Batu Gajah, Perak, Malaysia
| | - Hanisah Azhari
- Centre for Drug Delivery Technology, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia
| | - Mahendran Sekar
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Health Sciences, Universiti Kuala Lumpur Royal College of Medicine Perak, 30450 Ipoh, Perak, Malaysia
| | - Xiang Yi Chen
- Centre for Drug Delivery Technology, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia
| | - Mohd Cairul Iqbal Mohd Amin
- Centre for Drug Delivery Technology, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia.
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24
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Zhu J, Liu B, Shu X, Sun B. A novel mutation of walK confers vancomycin-intermediate resistance in methicillin-susceptible Staphylococcus aureus. Int J Med Microbiol 2021; 311:151473. [PMID: 33445057 DOI: 10.1016/j.ijmm.2021.151473] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 12/24/2020] [Accepted: 01/04/2021] [Indexed: 10/22/2022] Open
Abstract
With the treatment failure by vancomycin and poor clinical outcomes, the emergence and spread of vancomycin intermediate-resistant Staphylococcus aureus (VISA) has raised more concerns in recent years. While most VISA strains are isolated from methicillin-resistant S. aureus (MRSA), the mechanism underlying the generation of VISA from methicillin-susceptible S. aureus (MSSA) is still largely unknown. Here, we identified a total of 10 mutations in 9 genes through comparative genome analysis from laboratory-derived VISA strain. We verified the role of a novel mutation of WalK (I237T) and our results further indicated that the introduction of WalK (I237T) by allelic replacement can confer vancomycin resistance in MSSA with common VISA characteristics, including thickened cell walls, reduced autolysis, and attenuated virulence. Consistent with these phenotypes, real-time quantitative reverse transcription-PCR revealed the altered expression of several genes associated with cell wall metabolism and virulence control. In addition, electrophoretic mobility shift assay indicated that WalR can directly bind to the promoter regions of oatA, sle1, and mgt, fluorescence-based promoter activity and β-galactosidase assays revealed WalK (I237T) can alter promoter activities of oatA, mgt, and sle1, thus regulating genes expression. These findings broaden our understanding of the regulatory network by WalKR system and decipher the molecular mechanisms of developmental VISA resistance in MSSA with point mutations.
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Affiliation(s)
- Jiade Zhu
- Department of Oncology, The First Affiliated Hospital, CAS Key Laboratory of Innate Immunity and Chronic Disease, and Division of Life Sciences and Medicine, University of Science and Technology of China, Anhui, 230027, China
| | - Banghui Liu
- Department of Oncology, The First Affiliated Hospital, CAS Key Laboratory of Innate Immunity and Chronic Disease, and Division of Life Sciences and Medicine, University of Science and Technology of China, Anhui, 230027, China
| | - Xueqin Shu
- Department of Oncology, The First Affiliated Hospital, CAS Key Laboratory of Innate Immunity and Chronic Disease, and Division of Life Sciences and Medicine, University of Science and Technology of China, Anhui, 230027, China
| | - Baolin Sun
- Department of Oncology, The First Affiliated Hospital, CAS Key Laboratory of Innate Immunity and Chronic Disease, and Division of Life Sciences and Medicine, University of Science and Technology of China, Anhui, 230027, China.
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25
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Xu M, Hu Y, Xiao Y, Zhang Y, Sun K, Wu T, Lv N, Wang W, Ding W, Li F, Qiu B, Li J. Near-Infrared-Controlled Nanoplatform Exploiting Photothermal Promotion of Peroxidase-like and OXD-like Activities for Potent Antibacterial and Anti-biofilm Therapies. ACS APPLIED MATERIALS & INTERFACES 2020; 12:50260-50274. [PMID: 33108154 DOI: 10.1021/acsami.0c14451] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Nanozymes that mimic peroxidase (POD) activity can convert H2O2 into bactericidal free radicals, which is referred to as chemodynamic therapy (CDT). High glutathione (GSH) levels in the infectious tissue severely limit the performance of CDT. Herein, we report a near-infrared-controlled antibacterial nanoplatform that is based on encapsulating tungsten sulfide quantum dots (WS2QDs) and the antibiotic vancomycin in a thermal-sensitive liposome. The system exploits the photothermal sensitivity of the WS2QDs to achieve selective liposome rupture for the targeted drug delivery. We determined that WS2QDs show a strong POD-like activity under physiological conditions and the oxidase-like activity, which can oxidate GSH to further improve the CDT efficacy. Moreover, we found that increased temperature promotes multiple enzyme-mimicking activities of WS2QDs. This platform exerts antibacterial effects against Gram-positive Mu50 (a vancomycin-intermediate Staphylococcus aureus reference strain) and Gram-negative Escherichia coli and disrupts biofilms for improved penetration of therapeutic agents inside biofilms. In vivo studies with mice bearing Mu50-caused skin abscess revealed that this platform confers potent antibacterial activity without obvious toxicity. Accordingly, our work illustrates that the photothermal and nanozyme properties of WS2QDs can be deployed alongside a conventional therapeutic to achieve synergistic chemodynamic/photothermal/pharmaco therapy for powerful antibacterial effects.
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Affiliation(s)
- Mengran Xu
- Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui, China
| | - Yi Hu
- Hefei National Lab for Physical Sciences at the Microscale and the Centers for Biomedical Engineering, University of Science and Technology of China, Hefei 230027, China
| | - Ya Xiao
- Department of Stomatology, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui, China
| | - Yuanyuan Zhang
- Hefei National Lab for Physical Sciences at the Microscale and the Centers for Biomedical Engineering, University of Science and Technology of China, Hefei 230027, China
| | - Kaili Sun
- Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui, China
- Department of Infectious Diseases, The Chaohu Affiliated Hospital of Anhui Medical University, Chaohu 238000, Anhui, China
| | - Ting Wu
- Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui, China
| | - Na Lv
- Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui, China
- Department of Stomatology, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui, China
| | - Wenshen Wang
- Hefei National Lab for Physical Sciences at the Microscale and the Centers for Biomedical Engineering, University of Science and Technology of China, Hefei 230027, China
| | - Weiping Ding
- Hefei National Lab for Physical Sciences at the Microscale and the Centers for Biomedical Engineering, University of Science and Technology of China, Hefei 230027, China
| | - Fenfen Li
- Hefei National Lab for Physical Sciences at the Microscale and the Centers for Biomedical Engineering, University of Science and Technology of China, Hefei 230027, China
| | - Bensheng Qiu
- Hefei National Lab for Physical Sciences at the Microscale and the Centers for Biomedical Engineering, University of Science and Technology of China, Hefei 230027, China
| | - Jiabin Li
- Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui, China
- Department of Infectious Diseases, The Chaohu Affiliated Hospital of Anhui Medical University, Chaohu 238000, Anhui, China
- Anhui Center for Surveillance of Bacterial Resistance and Institute of Bacterial Resistance, Anhui Medical University, Hefei 230022, Anhui, China
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26
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Baseri N, Najar-Peerayeh S, Bakhshi B. The effect of subinhibitory concentration of chlorhexidine on the evolution of vancomycin-intermediate Staphylococcus aureus and the induction of mutations in walKR and vraTSR systems. INFECTION GENETICS AND EVOLUTION 2020; 87:104628. [PMID: 33171303 DOI: 10.1016/j.meegid.2020.104628] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 11/03/2020] [Accepted: 11/05/2020] [Indexed: 01/08/2023]
Abstract
The molecular mechanism underlying the development of vancomycin-intermediate Staphylococcus aureus (VISA) remains unclear. The abuses of antibacterial compounds lead to a change in the bacterial susceptibility patterns. Therefore, we examined the effect of Chlorhexidine (CHX) on in vitro development of VISA and reported CHX-selected VISA mutant Tm1 with phenotypic features similar to the clinical VISA isolates. WalKR, VraTSR, and GraSR are the most common regulatory systems involved in VISA evaluation. The expression of these systems, as well as walKR-regulated autolysins and VraTSR-regulated cell wall stimulon, were compared, by RT-qPCR, between the mutant and parental strains. The results revealed the downregulation of walKR, vraTSR, atlA, sle1, lytM, and pbpB genes in Tm1. The complete sequences of walKR and vraTSR genes was compared using the Sanger sequencing method. We detected Walk.R55C, WalR.A38T, and VraS·N340-D347del novel mutations in Tm1. These mutations were classified as deleterious mutations and predicted to affect protein function using the SIFT prediction algorithm. Novel mutations in Tm1 confirm the genetic diversity of VISA isolates. We suggest that WalKR and VraTSR may be involved in sense and response to CHX. In this regard, CHX may have a role in cell wall degradation of S. aureus and the emergence of VISA due to mutations in the CA domain of the Walk and VraS and the REC domain of WalR. Therefore, CHX should be used with caution.
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Affiliation(s)
- Neda Baseri
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Shahin Najar-Peerayeh
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Bita Bakhshi
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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27
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Jin Y, Yu X, Zhang S, Kong X, Chen W, Luo Q, Zheng B, Xiao Y. Comparative Analysis of Virulence and Toxin Expression of Vancomycin-Intermediate and Vancomycin-Sensitive Staphylococcus aureus Strains. Front Microbiol 2020; 11:596942. [PMID: 33193280 PMCID: PMC7661696 DOI: 10.3389/fmicb.2020.596942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 10/12/2020] [Indexed: 01/19/2023] Open
Abstract
Previous studies on vancomycin-intermediate Staphylococcus aureus (VISA) have mainly focused on drug resistance, the evolution of differences in virulence between VISA and vancomycin-sensitive S. aureus (VSSA) requires further investigation. To address this issue, in this study, we compared the virulence and toxin profiles of pair groups of VISA and VSSA strains, including a series of vancomycin-resistant induced S. aureus strains—SA0534, SA0534-V8, and SA0534-V16. We established a mouse skin infection model to evaluate the invasive capacity of VISA strains, and found that although mice infected with VISA had smaller-sized abscesses than those infected with VSSA, the abscesses persisted for a longer period (up to 9 days). Infection with VISA strains was associated with a lower mortality rate in Galleria mellonella larvae compared to infection with VSSA strains (≥ 40% vs. ≤ 3% survival at 28 h). Additionally, VISA were more effective in colonizing the nasal passage of mice than VSSA, and in vitro experiments showed that while VISA strains were less virulent they showed enhanced intracellular survival compared to VSSA strains. RNA sequencing of VISA strains revealed significant differences in the expression levels of the agr, hla, cap, spa, clfB, and sbi genes and suggested that platelet activation is only weakly induced by VISA. Collectively, our findings indicate that VISA is less virulent than VSSA but has a greater capacity to colonize human hosts and evade destruction by the host innate immune system, resulting in persistent and chronic S. aureus infection.
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Affiliation(s)
- Ye Jin
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiao Yu
- Department of Respiratory and Critical Care Medicine, First Hospital of Shanxi Medical University, Taiyuan, China
| | - Shuntian Zhang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaoyang Kong
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Weiwei Chen
- Department of Laboratory Medicine, College of Medicine, Zhejiang University, Hangzhou, China
| | - Qixia Luo
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Beiwen Zheng
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yonghong Xiao
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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28
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Chen CJ, Huang YC, Shie SS. Evolution of Multi-Resistance to Vancomycin, Daptomycin, and Linezolid in Methicillin-Resistant Staphylococcus aureus Causing Persistent Bacteremia. Front Microbiol 2020; 11:1414. [PMID: 32774327 PMCID: PMC7381330 DOI: 10.3389/fmicb.2020.01414] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/02/2020] [Indexed: 01/08/2023] Open
Abstract
The genomic evolution in vivo in persistent infection was critical information for understanding how methicillin-resistant Staphylococcus aureus (MRSA) was adapted to host environments with high antibiotic selective pressure. Thirty-two successive MRSA blood isolates with incremental non-susceptibility to vancomycin (VISA), daptomycin (DRSA), and/or linezolid (LRSA) were isolated from a patient failing multiple courses of antimicrobial therapy during 1,356 days of bacteremia. Whole genome sequencing (WGS) for all consecutive isolates were conducted to characterize the evolutionary pathways, resistance-associated mutations and their temporal relationship with antimicrobial treatment. The WGS-based phylogeny categorized the isogenic strains into three major clades, I (22 isolates), II (7 isolates), and III (3 isolates), respectively, harboring a median (range) of 7 (1–30), 62 (53–65), and 118 (100–130) non-synonymous mutations when compared to the very first isolate. Clade I strains were further grouped into early and late subclades, which, respectively, shared the most recent common ancestor with Clade III strains at day 393.7 and Clade II strain at day 662.5. Clade I and Clade III strains were characterized, respectively, with high rates of VISA (9/22, 40.9%) and VISA-and-DRSA phenotype (2/3, 66.7%). Linezolid-resistance including VISA-DRSA-and-LRSA phenotype was exclusively identified in Clade II strains after eight courses of linezolid treatment. The LRSA displayed a small colony variant phenotype and were associated with G2576T mutations in domain V region of 23S rRNA. Substantial loss of mobile elements or alleles mediating resistance or virulence were identified during the evolution of multi-resistance. However, the gene loss might not be correlated to the development of VISA, DRSA, or LRSA phenotype. In conclusion, MRSA in persistent bacteremia was adapted to harsh host environment through multiple pathways involving both resistance-associated mutations and extensive gene loss.
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Affiliation(s)
- Chih-Jung Chen
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan City, Taiwan.,School of Medicine, College of Medicine, Chang Gung University, Taoyuan City, Taiwan
| | - Yhu-Chering Huang
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan City, Taiwan.,School of Medicine, College of Medicine, Chang Gung University, Taoyuan City, Taiwan
| | - Shian-Sen Shie
- School of Medicine, College of Medicine, Chang Gung University, Taoyuan City, Taiwan.,Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital, Taoyuan City, Taiwan
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Single-nucleotide polymorphisms in a vancomycin-resistant Staphylococcus aureus strain based on whole-genome sequencing. Arch Microbiol 2020; 202:2255-2261. [PMID: 32535788 PMCID: PMC7455577 DOI: 10.1007/s00203-020-01906-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 02/02/2020] [Accepted: 05/11/2020] [Indexed: 01/04/2023]
Abstract
The emergence of vancomycin-resistant Staphylococcus aureus (VRSA) threatens global health. The mechanism of vancomycin resistance of VRSA without vanA gene acquisition was not fully elucidated. Therefore, we aimed to determine the mechanism of vancomycin resistance of VRSA besides that by vanA gene acquisition. In this study, we obtained vancomycin-resistant strains (V036-V64; MIC = 64 µg /ml) from susceptible strain (V036; MIC = 0.5 µg /ml) by exposure of vancomycin in vitro and examined the phenotypic characteristics and antibiotic susceptibility profiles of the resistant strain (V036-V64). To identify the genetic variations caused vancomycin resistance, we determined the complete genome sequences of V036 and V036-V64 and analyzed for single-nucleotide polymorphisms (SNPs) between two strains. Morphologically, V036-V64 had a twofold thicker cell wall compared with V036. Linezolid, rifampicin, and ceftaroline had similar MIC ranges against V036-V64 and V036, but V036-V64 showed lower susceptibilities to daptomycin and telavancin. We detected eight single-nucleotide polymorphisms differing between V036-V64 and V036: rimM (G16D), ssaA2 (G128A), rpsK (P60R), rpoB (R917C), walK (T492R), d-alanyl-d-alanine carboxypeptidase (L307I), vraT (A152V), and chromosome segregation ATPase (T440I). This study demonstrates that, under selective pressure, by the accumulation of mutations in genes related to cell wall synthesis, vancomycin-susceptible S. aureus can develop thicker cell walls and, hence, develop high vancomycin resistance. Thus, we highlight a novel vanA-negative mechanism for VRSA emergence.
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30
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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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31
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Olivieri FA, Burastero O, Drusin SI, Defelipe LA, Wetzler DE, Turjanski A, Marti M. Conformational and Reaction Dynamic Coupling in Histidine Kinases: Insights from Hybrid QM/MM Simulations. J Chem Inf Model 2020; 60:833-842. [PMID: 31923359 DOI: 10.1021/acs.jcim.9b00806] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Histidine kinases (HK) of bacterial two-component systems represent a hallmark of allosterism in proteins, being able to detect a signal through the sensor domain and transmit this information through the protein matrix to the kinase domain which, once active, autophosphorylates a specific histidine residue. Inactive-to-active transition results in a large conformational change that moves the kinase on top of the histidine. In the present work, we use several molecular simulation techniques (Molecular Dynamics, Hybrid QM/MM, and constant pH molecular dynamics) to study the activation and autophosphorylation reactions in L. plantarum WalK, a cis-acting HK. In agreement with previous results, we show that the chemical step requires tight coupling with the conformational step in order to maintain the histidine phosphoacceptor in the correct tautomeric state, with a reactive δ-nitrogen. During the conformational transition, the kinase domain is never released and walks along the HK helix axis, breaking and forming several conserved residue-based contacts. The phosphate transfer reaction is concerted in the transition state region and is catalyzed through the stabilization of the negative developing charge of transferring phosphate along the reaction.
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Affiliation(s)
- Federico A Olivieri
- Departamento de Quı́mica Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires, Ciudad Universitaria , Intendente Guiraldes 2160 , C1428EGA Ciudad Autónoma de Buenos Aires , Argentina.,Instituto de Quı́mica Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET , Ciudad Universitaria , Intendente Guiraldes 2160 , C1428EGA Ciudad Autónoma de Buenos Aires , Argentina
| | - Osvaldo Burastero
- Departamento de Quı́mica Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires, Ciudad Universitaria , Intendente Guiraldes 2160 , C1428EGA Ciudad Autónoma de Buenos Aires , Argentina.,Instituto de Quı́mica Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET , Ciudad Universitaria , Intendente Guiraldes 2160 , C1428EGA Ciudad Autónoma de Buenos Aires , Argentina
| | - Salvador I Drusin
- Departamento de Quı́mica Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires, Ciudad Universitaria , Intendente Guiraldes 2160 , C1428EGA Ciudad Autónoma de Buenos Aires , Argentina.,Instituto de Quı́mica Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET , Ciudad Universitaria , Intendente Guiraldes 2160 , C1428EGA Ciudad Autónoma de Buenos Aires , Argentina.,Área Fı́sica, Departamento de Quı́mico-Fı́sica, Facultad de Ciencias Bioquı́micas y Farmacéuticas , Universidad Nacional de Rosario , Suipacha 531 , S2002LRK Rosario , Santa Fe , Argentina
| | - Lucas A Defelipe
- Departamento de Quı́mica Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires, Ciudad Universitaria , Intendente Guiraldes 2160 , C1428EGA Ciudad Autónoma de Buenos Aires , Argentina.,Instituto de Quı́mica Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET , Ciudad Universitaria , Intendente Guiraldes 2160 , C1428EGA Ciudad Autónoma de Buenos Aires , Argentina.,European Molecular Biology Laboratory Hamburg , Notkestrasse 85 , D-22607 Hamburg , Germany
| | - Diana E Wetzler
- Departamento de Quı́mica Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires, Ciudad Universitaria , Intendente Guiraldes 2160 , C1428EGA Ciudad Autónoma de Buenos Aires , Argentina.,Instituto de Quı́mica Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET , Ciudad Universitaria , Intendente Guiraldes 2160 , C1428EGA Ciudad Autónoma de Buenos Aires , Argentina
| | - Adrián Turjanski
- Departamento de Quı́mica Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires, Ciudad Universitaria , Intendente Guiraldes 2160 , C1428EGA Ciudad Autónoma de Buenos Aires , Argentina.,Instituto de Quı́mica Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET , Ciudad Universitaria , Intendente Guiraldes 2160 , C1428EGA Ciudad Autónoma de Buenos Aires , Argentina
| | - Marcelo Marti
- Departamento de Quı́mica Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires, Ciudad Universitaria , Intendente Guiraldes 2160 , C1428EGA Ciudad Autónoma de Buenos Aires , Argentina.,Instituto de Quı́mica Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET , Ciudad Universitaria , Intendente Guiraldes 2160 , C1428EGA Ciudad Autónoma de Buenos Aires , Argentina
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Ahmad A, Majaz S, Nouroz F. Two-component systems regulate ABC transporters in antimicrobial peptide production, immunity and resistance. Microbiology (Reading) 2020; 166:4-20. [DOI: 10.1099/mic.0.000823] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Bacteria offer resistance to a broad range of antibiotics by activating their export channels of ATP-binding cassette transporters. These transporters perform a central role in vital processes of self-immunity, antibiotic transport and resistance. The majority of ATP-binding cassette transporters are capable of detecting the presence of antibiotics in an external vicinity and are tightly regulated by two-component systems. The presence of an extracellular loop and an adjacent location of both the transporter and two-component system offers serious assistance to induce a quick and specific response against antibiotics. Both systems have demonstrated their ability of sensing such agents, however, the exact mechanism is not yet fully established. This review highlighted the three key functions of antibiotic resistance, transport and self-immunity of ATP-binding cassette transporters and an adjacent two-component regulatory system.
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Affiliation(s)
- Ashfaq Ahmad
- Department of Bioinformatics, Hazara University, Mansehra, KPK, Pakistan
| | - Sidra Majaz
- Department of Bioinformatics, Hazara University, Mansehra, KPK, Pakistan
| | - Faisal Nouroz
- Department of Bioinformatics, Hazara University, Mansehra, KPK, Pakistan
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Gostev V, Sopova J, Kalinogorskaya O, Tsvetkova I, Lobzin Y, Klotchenko S, Sidorenko S. In Vitro Ceftaroline Resistance Selection of Methicillin-Resistant Staphylococcus aureus Involves Different Genetic Pathways. Microb Drug Resist 2019; 25:1401-1409. [PMID: 31329022 DOI: 10.1089/mdr.2019.0130] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The pathways in the development of ceftaroline resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolates belonging to the ST8, ST239, and ST228 were evaluated. Ceftaroline-resistant derivatives were isolated through selection during 40 passages. Ceftaroline MIC measurements and whole-genome sequencing were performed after 5, 20, and 40 passages. In two ST8 derivative isolates, ceftaroline MIC increased up to 128 mg/L. Mutations were acquired in gdpP and graS in one isolate after 20 passages and in gdpP in another after 40 passages. MIC for two ST239 derivatives increased to 128 mg/L. Substitutions in Pbp4 and polymorphisms in the upstream region of pbp4 were identified in both derivatives after 40 passages. In one isolate, additional mutation in gdpP and deletion in graR were detected. In an ST228 derivative, MIC increased to 32 mg/L with one mutation in penicillin-binding protein 2a (Y446N) detected after five passages and a second (E447K) after 20 passages. Three pathways in the development of ceftaroline resistance were identified. For ST8 and ST239 derivatives mutations were detected in gdpP and pbp4, respectively, whereas in ST228 - in mecA. Most derivatives harbored additional mutations whose potential role in the development of resistance has not been determined.
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Affiliation(s)
- Vladimir Gostev
- Department of Medical Microbiology and Molecular Epidemiology, Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia
- Department of Medical Microbiology, North-Western State Medical University named after I.I. Mechnikov, Saint Petersburg, Russia
| | - Julia Sopova
- Laboratory of Genetic Models of Human Diseases, Saint Petersburg Branch of Vavilov Institute of General Genetics, Saint Petersburg, Russia
- Department of Genetics and Biotechnology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Olga Kalinogorskaya
- Department of Medical Microbiology and Molecular Epidemiology, Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia
| | - Irina Tsvetkova
- Department of Medical Microbiology and Molecular Epidemiology, Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia
| | - Yuri Lobzin
- Department of Medical Microbiology and Molecular Epidemiology, Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia
- Department of Medical Microbiology, North-Western State Medical University named after I.I. Mechnikov, Saint Petersburg, Russia
| | - Sergey Klotchenko
- Division of Viral Molecular Biology, Smorodintsev Research Institute of Influenza, Saint Petersburg, Russia
| | - Sergey Sidorenko
- Department of Medical Microbiology and Molecular Epidemiology, Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia
- Department of Medical Microbiology, North-Western State Medical University named after I.I. Mechnikov, Saint Petersburg, Russia
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Cong Y, Yang S, Rao X. Vancomycin resistant Staphylococcus aureus infections: A review of case updating and clinical features. J Adv Res 2019; 21:169-176. [PMID: 32071785 PMCID: PMC7015472 DOI: 10.1016/j.jare.2019.10.005] [Citation(s) in RCA: 220] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 10/02/2019] [Accepted: 10/09/2019] [Indexed: 01/08/2023] Open
Abstract
MRSA infection is a global threat to public health. Vancomycin is one of the first-line drugs for the treatment of MRSA infections. MRSA with complete resistance to vancomycin have emerged in recent years. The total number of VRSA isolates is updated in this paper. Resistance mechanisms, characteristics of VRSA infections, as well as clinical treatments are reviewed.
The infection caused by methicillin-resistant Staphylococcus aureus (MRSA) is a global threat to public health. Vancomycin remains one of the first-line drugs for the treatment of MRSA infections. However, S. aureus isolates with complete resistance to vancomycin have emerged in recent years. Vancomycin-resistant S. aureus (VRSA) is mediated by a vanA gene cluster, which is transferred from vancomycin-resistant enterococcus. Since the first VRSA isolate was recovered from Michigan, USA in 2002, 52 VRSA strains have been isolated worldwide. In this paper, we review the latest progresses in VRSA, highlighting its resistance mechanism, characteristics of VRSA infections, as well as clinical treatments.
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Affiliation(s)
- Yanguang Cong
- Department of Clinical Laboratory, Traditional Medicine Hospital Affiliated to Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Sijin Yang
- Department of Cardiovascular Disease, Traditional Medicine Hospital Affiliated to Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Xiancai Rao
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University (Third Military Medical University), Chongqing 400038, China
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35
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G C B, Sahukhal GS, Elasri MO. Role of the msaABCR Operon in Cell Wall Biosynthesis, Autolysis, Integrity, and Antibiotic Resistance in Staphylococcus aureus. Antimicrob Agents Chemother 2019; 63:e00680-19. [PMID: 31307991 PMCID: PMC6761503 DOI: 10.1128/aac.00680-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 07/10/2019] [Indexed: 12/20/2022] Open
Abstract
Staphylococcus aureus is an important human pathogen in both community and health care settings. One of the challenges with S. aureus as a pathogen is its acquisition of antibiotic resistance. Previously, we showed that deletion of the msaABCR operon reduces cell wall thickness, resulting in decreased resistance to vancomycin in vancomycin-intermediate S. aureus (VISA). In this study, we investigated the nature of the cell wall defect in the msaABCR operon mutant in the Mu50 (VISA) and USA300 LAC methicillin-resistant Staphylococcus aureus (MRSA) strains. Results showed that msaABCR mutant cells had decreased cross-linking in both strains. This defect is typically due to increased murein hydrolase activity and/or nonspecific processing of murein hydrolases mediated by increased protease activity in mutant cells. The defect was enhanced by a decrease in teichoic acid content in the msaABCR mutant. Therefore, we propose that deletion of the msaABCR operon results in decreased peptidoglycan cross-linking, leading to increased susceptibility toward cell wall-targeting antibiotics, such as β-lactams and vancomycin. Moreover, we also observed significantly downregulated transcription of early cell wall-synthesizing genes, supporting the finding that msaABCR mutant cells have decreased peptidoglycan synthesis. More specifically, the msaABCR mutant in the USA300 LAC strain (MRSA) showed significantly reduced expression of the murA gene, whereas the msaABCR mutant in the Mu50 strain (VISA) showed significantly reduced expression of glmU, murA, and murD Thus, we conclude that the msaABCR operon controls the balance between cell wall synthesis and cell wall hydrolysis, which is required for maintaining a robust cell wall and acquiring resistance to cell wall-targeting antibiotics, such as vancomycin and the β-lactams.
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Affiliation(s)
- Bibek G C
- Cell and Molecular Biology, The University of Southern Mississippi, Hattiesburg, Mississippi, USA
| | - Gyan S Sahukhal
- Cell and Molecular Biology, The University of Southern Mississippi, Hattiesburg, Mississippi, USA
| | - Mohamed O Elasri
- Cell and Molecular Biology, The University of Southern Mississippi, Hattiesburg, Mississippi, USA
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36
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Role of MurT C-Terminal Domain in the Amidation of Staphylococcus aureus Peptidoglycan. Antimicrob Agents Chemother 2019; 63:AAC.00957-19. [PMID: 31358586 DOI: 10.1128/aac.00957-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/20/2019] [Indexed: 11/20/2022] Open
Abstract
Glutamate amidation, a secondary modification of the peptidoglycan, was first identified in Staphylococcus aureus It is catalyzed by the protein products of the murT and gatD genes, which are conserved and colocalized in the genomes of most sequenced Gram-positive bacterial species. The MurT-GatD complex is required for cell viability, full resistance to β-lactam antibiotics, and resistance to human lysozyme and is recognized as an attractive target for new antimicrobials. Great effort has been invested in the study of this step, culminating recently in three independent reports addressing the structural elucidation of the MurT-GatD complex. In this work, we demonstrate through the use of nonstructural approaches the critical and multiple roles of the C-terminal domain of MurT, annotated as DUF1727, in the MurT-GatD enzymatic complex. This domain provides the physical link between the two enzymatic activities and is essential for the amidation reaction. Copurification of recombinant MurT and GatD proteins and bacterial two-hybrid assays support the observation that the MurT-GatD interaction occurs through this domain. Most importantly, we provide in vivo evidence of the effect of substitutions at specific residues in DUF1727 on cell wall peptidoglycan amidation and on the phenotypes of oxacillin resistance and bacterial growth.
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Abstract
Dating back to the 1960s, initial studies on the staphylococcal cell wall were driven by the need to clarify the mode of action of the first antibiotics and the resistance mechanisms developed by the bacteria. During the following decades, the elucidation of the biosynthetic path and primary composition of staphylococcal cell walls was propelled by advances in microbial cell biology, specifically, the introduction of high-resolution analytical techniques and molecular genetic approaches. The field of staphylococcal cell wall gradually gained its own significance as the complexity of its chemical structure and involvement in numerous cellular processes became evident, namely its versatile role in host interactions, coordination of cell division and environmental stress signaling.This chapter includes an updated description of the anatomy of staphylococcal cell walls, paying particular attention to information from the last decade, under four headings: high-resolution analysis of the Staphylococcus aureus peptidoglycan; variations in peptidoglycan composition; genetic determinants and enzymes in cell wall synthesis; and complex functions of cell walls. The latest contributions to a more precise picture of the staphylococcal cell envelope were possible due to recently developed state-of-the-art microscopy and spectroscopy techniques and to a wide combination of -omics approaches, that are allowing to obtain a more integrative view of this highly dynamic structure.
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Affiliation(s)
- Rita Sobral
- UCIBIO-REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
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Dai Y, Gao C, Chen L, Chang W, Yu W, Ma X, Li J. Heterogeneous Vancomycin-Intermediate Staphylococcus aureus Uses the VraSR Regulatory System to Modulate Autophagy for Increased Intracellular Survival in Macrophage-Like Cell Line RAW264.7. Front Microbiol 2019; 10:1222. [PMID: 31214151 PMCID: PMC6554704 DOI: 10.3389/fmicb.2019.01222] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 05/16/2019] [Indexed: 12/14/2022] Open
Abstract
The VraSR two-component system is a vancomycin resistance-associated sensor/regulator that is upregulated in vancomycin-intermediate Staphylococcus aureus (VISA) and heterogeneous VISA (hVISA) strains. VISA/hVISA show reduced susceptibility to vancomycin and an increased ability to evade host immune responses, resulting in enhanced clinical persistence. However, the underlying mechanism remains unclear. Recent studies have reported that S. aureus strains have developed some strategies to survive within the host cell by using autophagy processes. In this study, we confirmed that clinical isolates with high vraR expression showed increased survival in murine macrophage-like RAW264.7 cells. We constructed isogenic vraSR deletion strain Mu3ΔvraSR and vraSR-complemented strain Mu3ΔvraSR-C to ascertain whether S. aureus uses the VraSR system to modulate autophagy for increasing intracellular survival in RAW264.7. Overall, the survival of Mu3ΔvraSR in RAW264.7 cells was reduced at all infection time points compared with that of the Mu3 wild-type strain. Mu3ΔvraSR-infected RAW264.7 cells also showed decreased transcription of autophagy-related genes Becn1 and Atg5, decreased LC3-II turnover and increased p62 degradation, and fewer visible punctate LC3 structures. In addition, we found that inhibition of autophagic flux significantly increased the survival of Mu3ΔvraSR in RAW264.7 cells. Together, these results demonstrate that S. aureus uses the VraSR system to modulate host-cell autophagy processes for increasing its own survival within macrophages. Our study provides novel insights into the impact of VraSR on bacterial infection and will help to further elucidate the relationship between bacteria and the host immune response. Moreover, understanding the autophagic pathway in vraSR associated immunity has potentially important implications for preventing or treating VISA/hVISA infection.
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Affiliation(s)
- Yuanyuan Dai
- Department of Infectious Diseases, First Affiliated Hospital of Anhui Medical University, Hefei, China.,Department of Clinical Laboratory, First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Caihong Gao
- Department of Infectious Diseases, First Affiliated Hospital of Anhui Medical University, Hefei, China.,Department of Clinical Laboratory, First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Li Chen
- Department of Clinical Laboratory, First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Wenjiao Chang
- Department of Clinical Laboratory, First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Wenwei Yu
- Department of Clinical Laboratory, First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Xiaoling Ma
- Department of Clinical Laboratory, First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Jiabin Li
- Department of Infectious Diseases, First Affiliated Hospital of Anhui Medical University, Hefei, China.,Anhui Center for Surveillance of Bacterial Resistance, Hefei, China.,Department of Infectious Diseases, Chaohu Hospital of Anhui Medical University, Hefei, China
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Brignoli T, Manetti AGO, Rosini R, Haag AF, Scarlato V, Bagnoli F, Delany I. Absence of Protein A Expression Is Associated With Higher Capsule Production in Staphylococcal Isolates. Front Microbiol 2019; 10:863. [PMID: 31133995 PMCID: PMC6523524 DOI: 10.3389/fmicb.2019.00863] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 04/04/2019] [Indexed: 12/19/2022] Open
Abstract
Staphylococcus aureus is a major human pathogen, and a leading cause of soft tissue and blood stream infections. One of the causes of its success as a pathogen is the peculiar array of immune evasion factors through which the bacterium avoids host defenses, where the staphylococcal protein A (SpA) plays a major role thanks to its IgG binding activities. Moreover, SpA has recently been proposed as a promising vaccine antigen. In this study, we evaluated the expression of SpA in a collection of staphylococcal strains, about 7% of which did not express SpA (SpA- strains), despite the presence of the gene. By a comparative genomic analysis, we identified that a mutation in the spa 5′ UTR sequence affecting the RBS is responsible for the loss of SpA in a subset of SpA- strains. Using a high-throughput qRT-PCR approach on a selected panel of virulence-related genes, we identified that the SpA- phenotype is associated with lower spa transcript levels and increased expression and production of capsule as well as other changes in the transcription of several key virulence factors. Our data suggest that the SpA- phenotype has occurred in geographically distinct strains through different molecular mechanisms including both mutation, leading likely to translation alterations, and transcriptional deregulation. Furthermore, we provide evidence that SpA- strains are highly susceptible to phagocytic uptake mediated by anti-capsule antibodies. These data suggest that S. aureus may alter its virulence factor expression pattern as an adaptation to the host or environment. Vaccination strategies targeting both SpA and capsule could therefore result in broader coverage against staphylococcal isolates than SpA alone.
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Affiliation(s)
- Tarcisio Brignoli
- GSK Vaccines, Siena, Italy.,Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Bologna, Italy
| | | | | | - Andreas F Haag
- GSK Vaccines, Siena, Italy.,Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Vincenzo Scarlato
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Bologna, Italy
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40
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Abstract
Staphylococcus aureus is capable of becoming resistant to all classes of antibiotics clinically available and resistance can develop through de novo mutations in chromosomal genes or through acquisition of horizontally transferred resistance determinants. This review covers the most important antibiotics available for treatment of S. aureus infections and a special emphasis is dedicated to the current knowledge of the wide variety of resistance mechanisms that S. aureus employ to withstand antibiotics. Since resistance development has been inevitable for all currently available antibiotics, new therapies are continuously under development. Besides development of new small molecules affecting cell viability, alternative approaches including anti-virulence and bacteriophage therapeutics are being investigated and may become important tools to combat staphylococcal infections in the future.
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Copin R, Sause WE, Fulmer Y, Balasubramanian D, Dyzenhaus S, Ahmed JM, Kumar K, Lees J, Stachel A, Fisher JC, Drlica K, Phillips M, Weiser JN, Planet PJ, Uhlemann AC, Altman DR, Sebra R, van Bakel H, Lighter J, Torres VJ, Shopsin B. Sequential evolution of virulence and resistance during clonal spread of community-acquired methicillin-resistant Staphylococcus aureus. Proc Natl Acad Sci U S A 2019; 116:1745-1754. [PMID: 30635416 PMCID: PMC6358666 DOI: 10.1073/pnas.1814265116] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The past two decades have witnessed an alarming expansion of staphylococcal disease caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). The factors underlying the epidemic expansion of CA-MRSA lineages such as USA300, the predominant CA-MRSA clone in the United States, are largely unknown. Previously described virulence and antimicrobial resistance genes that promote the dissemination of CA-MRSA are carried by mobile genetic elements, including phages and plasmids. Here, we used high-resolution genomics and experimental infections to characterize the evolution of a USA300 variant plaguing a patient population at increased risk of infection to understand the mechanisms underlying the emergence of genetic elements that facilitate clonal spread of the pathogen. Genetic analyses provided conclusive evidence that fitness (manifest as emergence of a dominant clone) changed coincidently with the stepwise emergence of (i) a unique prophage and mutation of the regulator of the pyrimidine nucleotide biosynthetic operon that promoted abscess formation and colonization, respectively, thereby priming the clone for success; and (ii) a unique plasmid that conferred resistance to two topical microbiocides, mupirocin and chlorhexidine, frequently used for decolonization and infection prevention. The resistance plasmid evolved through successive incorporation of DNA elements from non-S. aureus spp. into an indigenous cryptic plasmid, suggesting a mechanism for interspecies genetic exchange that promotes antimicrobial resistance. Collectively, the data suggest that clonal spread in a vulnerable population resulted from extensive clinical intervention and intense selection pressure toward a pathogen lifestyle that involved the evolution of consequential mutations and mobile genetic elements.
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Affiliation(s)
- Richard Copin
- Division of Infectious Diseases and Immunology, Department of Medicine, New York University School of Medicine, New York, NY 10016
| | - William E Sause
- Department of Microbiology, New York University School of Medicine, New York, NY 10016
| | - Yi Fulmer
- Division of Infectious Diseases and Immunology, Department of Medicine, New York University School of Medicine, New York, NY 10016
| | - Divya Balasubramanian
- Department of Microbiology, New York University School of Medicine, New York, NY 10016
| | - Sophie Dyzenhaus
- Department of Microbiology, New York University School of Medicine, New York, NY 10016
| | - Jamil M Ahmed
- Division of Infectious Diseases and Immunology, Department of Medicine, New York University School of Medicine, New York, NY 10016
| | - Krishan Kumar
- Division of Infectious Diseases and Immunology, Department of Medicine, New York University School of Medicine, New York, NY 10016
| | - John Lees
- Department of Microbiology, New York University School of Medicine, New York, NY 10016
| | - Anna Stachel
- Division of Infectious Diseases and Immunology, Department of Medicine, New York University School of Medicine, New York, NY 10016
| | - Jason C Fisher
- Division of Pediatric Surgery, Department of Surgery, New York University School of Medicine, New York, NY 10016
| | - Karl Drlica
- Public Health Research Institute, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Rutgers University, Newark, NJ 07103
- Department of Microbiology, Biochemistry, and Molecular Genetics, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Rutgers University, Newark, NJ 07103
| | - Michael Phillips
- Division of Infectious Diseases and Immunology, Department of Medicine, New York University School of Medicine, New York, NY 10016
| | - Jeffrey N Weiser
- Department of Microbiology, New York University School of Medicine, New York, NY 10016
| | - Paul J Planet
- Department of Pediatric Infectious Disease, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Anne-Catrin Uhlemann
- Division of Infectious Diseases, Department of Medicine, Columbia University Medical Center, New York, NY 10032
| | - Deena R Altman
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York City, NY 10029
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Robert Sebra
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Harm van Bakel
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Jennifer Lighter
- Division of Pediatric Infectious Diseases, Department of Pediatrics, New York University School of Medicine, New York, NY 10016
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, NY 10016;
| | - Bo Shopsin
- Division of Infectious Diseases and Immunology, Department of Medicine, New York University School of Medicine, New York, NY 10016;
- Department of Microbiology, New York University School of Medicine, New York, NY 10016
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Wu S, Huang F, Zhang H, Lei L. Staphylococcus aureus biofilm organization modulated by YycFG two-component regulatory pathway. J Orthop Surg Res 2019; 14:10. [PMID: 30621792 PMCID: PMC6325680 DOI: 10.1186/s13018-018-1055-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 12/27/2018] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Staphylococcus aureus (S. aureus) infection accounts for more than 50% of the osteomyelitis cases. Currently, methicillin-resistant S. aureus (MRSA) strains present an urgent medical problem. The YycFG two-component regulatory system (TCS) can allow bacteria to rapidly adapt to physical, chemical, and biological stresses. To define the role of YycFG in modulation virulence of S. aureus in osteomyelitis, we isolated clinical MRSA strains and compared these with ATCC29213 methicillin-sensitive S. aureus (MSSA). METHODS In the present study, 13 MRSA strains from chronic osteomyelitis tissues were isolated. The in-depth sequencing of 16S rRNA amplicons of the samples was conducted. Bacterial growth was monitored, and biofilm biomass was determined by crystal violet microtiter assay. Furthermore, quantitative RT-PCR analysis was adopted to identify the expression of yycF/G/H and icaA/D in MRSA and MSSA strains. Analysis of variance with one-way ANOVA was used for statistical analysis. RESULTS The in-depth sequencing of 16S rRNA amplicons of the clinical samples indicated a polymicrobial infection, with the phylum Firmicutes made up 13% of the microbial population. The MRSA strains showed an accelerated growth rate compared to the MSSA strains. Of note, MRSA biofilms showed an accumulation of an intercellular polysaccharides matrix and enhanced biomass upon microscopic examination. Furthermore, MRSA strains had a higher expression of the yycF/G/H and icaA/D genes and adhesion force. CONCLUSIONS These data suggested the roles of intercellular polysaccharide in S. aureus pathogenesis, indicating a possible association between YycFG pathways and MRSA strain virulence.
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Affiliation(s)
- Shizhou Wu
- Department of Orthopedics, West China Hospital , Sichuan University, No. 37 Guoxue Alley, Wuhou District, Chengdu City, 610041, Sichuan, People's Republic of China.,West China Hospital, West China Medical School, Sichuan University, Chengdu, People's Republic of China
| | - Fuguo Huang
- Department of Orthopedics, West China Hospital , Sichuan University, No. 37 Guoxue Alley, Wuhou District, Chengdu City, 610041, Sichuan, People's Republic of China.,West China Hospital, West China Medical School, Sichuan University, Chengdu, People's Republic of China
| | - Hui Zhang
- Department of Orthopedics, West China Hospital , Sichuan University, No. 37 Guoxue Alley, Wuhou District, Chengdu City, 610041, Sichuan, People's Republic of China. .,West China Hospital, West China Medical School, Sichuan University, Chengdu, People's Republic of China.
| | - Lei Lei
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, No. 14 Renmin South Road, Wuhou District, Chengdu City, 610041, Sichuan, People's Republic of China.
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Emergence of a dalbavancin induced glycopeptide/lipoglycopeptide non-susceptible Staphylococcus aureus during treatment of a cardiac device-related endocarditis. Emerg Microbes Infect 2018; 7:202. [PMID: 30514923 PMCID: PMC6279813 DOI: 10.1038/s41426-018-0205-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 11/03/2018] [Accepted: 11/11/2018] [Indexed: 11/08/2022]
Abstract
In the present study, we demonstrated the emergence of dalbavancin non-susceptible and teicoplanin-resistant Staphylococcus aureus small colony variants which were selected in vivo through long-term treatment with dalbavancin. A 36-year-old man presented with a cardiac device-related S. aureus endocarditis and received long-term therapy with dalbavancin. Consecutively, two glycopeptide/lipoglycopeptide susceptible and two non-susceptible S. aureus isolates were obtained from blood cultures and the explanted pacemaker wire. The isolates were characterized by: standard typing methods, antimicrobial susceptibility testing, auxotrophic profiling, proliferation assays, scanning and transmission electron microscopy, as well as whole genome sequencing. The isolated SCVs demonstrated a vancomycin-susceptible but dalbavancin non-susceptible and teicoplanin-resistant phenotype whereof the respective MICs of the last isolate were 16- and 84-fold higher than the susceptible strains. All four strains were indistinguishable or at least closely related by standard typing methods (spa, MLST, and PFGE), and whole genome sequencing revealed only eight sequence variants. A consecutive increase in cell wall thickness (up to 2.1-fold), an impaired cell separation with incomplete or multiple cross walls and significantly reduced growth rates were observed in the present study. Therefore, the mutations in pbp2 and the DHH domain of GdpP were identified as the most probable candidates due to their implication in the biosynthesis and metabolism of the staphylococcal cell wall. For the first time, we demonstrated in vivo induced dalbavancin non-susceptible/teicoplanin resistant, but vancomycin and daptomycin susceptible S. aureus SCVs without lipopeptide or glycopeptide pretreatment, thus, indicating the emergence of a novel lipoglycopeptide resistance mechanism.
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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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Bernstein DT, Haruno LS, Daram S, Dawson JR, Zhang W, Rosenfeld SB. Patient Factors Associated With Methicillin-Resistant Staphylococcus aureus Septic Arthritis in Children. Orthopedics 2018; 41:e277-e282. [PMID: 29451940 DOI: 10.3928/01477447-20180213-04] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Accepted: 12/15/2017] [Indexed: 02/03/2023]
Abstract
Staphylococcus aureus is the most common causative organism in pediatric septic arthritis, with methicillin-resistant Staphylococcus aureus (MRSA) being responsible for a significant portion of these infections. Early identification and initiation of proper treatment may improve outcomes by minimizing potential morbidity. The purpose of this study was to identify variables obtained on initial patient presentation associated with MRSA septic arthritis. Sixteen factors were retrospectively evaluated in 109 consecutive pediatric patients diagnosed with culture-confirmed septic arthritis. Graphical and logistical regression analyses were employed to determine factors independently predictive of MRSA septic arthritis. Twenty-seven (25%) patients had MRSA and 82 (75%) had non-MRSA septic arthritis. C-reactive protein of 13.7 mg/L or greater, duration of symptoms of 4 days or more, heart rate of 126 beats per minute or greater, and absolute neutrophil count of 8.72×103 cells/µL or greater were associated with MRSA septic arthritis. Ultimately, 98% of patients with 1 or no risk factors had non-MRSA and 96% of patients with MRSA septic arthritis had 2 or more positive risk factors. Elevated C-reactive protein, duration of symptoms, heart rate, and absolute neutrophil count are predictive of MRSA infection in the setting of pediatric septic arthritis and can be obtained on initial evaluation. In patients for whom there is concern for MRSA infection, this may guide more expedient treatment, such as early initiation of contact precautions and appropriate antibiotic therapy before culture results become available. [Orthopedics. 2018; 41(2):e277-e282.].
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Lin LC, Chang SC, Ge MC, Liu TP, Lu JJ. Novel single-nucleotide variations associated with vancomycin resistance in vancomycin-intermediate Staphylococcus aureus. Infect Drug Resist 2018; 11:113-123. [PMID: 29403293 PMCID: PMC5783010 DOI: 10.2147/idr.s148335] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Prolonged vancomycin usage may cause methicillin-resistant Staphylococcus aureus to become vancomycin-intermediate S. aureus (VISA) and heterogeneous VISA (hVISA). Mechanisms of vancomycin resistance of VISA and hVISA are still unclear. In this study, analyses of nucleotide sequence variations in 30 vancomycin-sensitive S. aureus (VSSA), 41 hVISA and 16 VISA isolates revealed 29 single-nucleotide variations in 12 genes (fmtC, graR, graS, htrA, mecA, pbp2, pbp4, srtA, tcaA, upps, vicK and vraR) that are related to cell wall synthesis or the two-component system. Six of these 29 single-nucleotide variations were novel and resulted in the following amino acid changes: Q692E in FmtC; T278I, P306L and I311T in HtrA; and I63V and K101E in Upps. Since P306L and I311T in HtrA and I63V in Upps were present in the majority (76.7%–86.7%) of VSSA isolates, these three amino acid variations may not be associated with vancomycin resistance. The other three amino acid variations (T278I in HtrA, K101E in Upps and Q692E in FmtC) were present in the majority (87.5%–93.8%) of hVISA and VISA isolates, but only in a small number (22.9%–25.7%) of VSSA isolates, suggesting that they are associated with vancomycin resistance.
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Affiliation(s)
- Lee-Chung Lin
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
| | - Shih-Cheng Chang
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan.,Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Mao-Cheng Ge
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
| | - Tsui-Ping Liu
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
| | - Jang-Jih Lu
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan.,Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan
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Peng H, Hu Q, Shang W, Yuan J, Zhang X, Liu H, Zheng Y, Hu Z, Yang Y, Tan L, Li S, Hu X, Li M, Rao X. WalK(S221P), a naturally occurring mutation, confers vancomycin resistance in VISA strain XN108. J Antimicrob Chemother 2017; 72:1006-1013. [PMID: 27999059 DOI: 10.1093/jac/dkw518] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 11/03/2016] [Indexed: 02/06/2023] Open
Abstract
Objectives Vancomycin-intermediate Staphylococcus aureus (VISA) strains have spread globally. We previously isolated an ST239 VISA (XN108) with a vancomycin MIC of 12 mg/L. The mechanism for XN108 resistance to vancomycin was investigated in this study. Methods Genome comparison was performed to characterize mutations that might contribute to the XN108 resistance phenotype. The novel mutation WalK(S221P) was identified and investigated using allelic replacement experiments. Vancomycin susceptibilities, autolytic activities and morphologies of the strains were examined. Autophosphorylation activities of WalK and the WalK(S221P) mutant were determined in vitro with [λ- 32 P]ATP, and binding activity of WalK(S221P)-activated WalR to the promoter region of its target gene lytM was determined by electrophoretic mobility shift assay. Results Genome comparison revealed three mutations, GraS(T136I), RpoB(H481N) and WalK(S221P), which might be responsible for vancomycin resistance in XN108. The introduction of WalK(S221P) to the vancomycin-susceptible strain N315 increased its vancomycin MIC from 1.5 to 8 mg/L, whereas the allelic replacement of WalK(S221P) with the native N315 WalK allele in XN108 decreased its vancomycin MIC from 12 to 4 mg/L. The VISA strains have thickened cell walls and decreased autolysis, consistent with observed changes in the expression of genes involved in cell wall metabolism and virulence regulation. WalK(S221P) exhibited reduced autophosphorylation, which may lead to reduced phosphorylation of WalR. WalK(S221P)-phosphorylated WalR also exhibited a reduced capacity to bind to the lytM promoter. Conclusions The naturally occurring WalK(S221P) mutation plays a key role in vancomycin resistance in XN108.
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Werth BJ, Jain R, Hahn A, Cummings L, Weaver T, Waalkes A, Sengupta D, Salipante SJ, Rakita RM, Butler-Wu SM. Emergence of dalbavancin non-susceptible, vancomycin-intermediate Staphylococcus aureus (VISA) after treatment of MRSA central line-associated bloodstream infection with a dalbavancin- and vancomycin-containing regimen. Clin Microbiol Infect 2017; 24:429.e1-429.e5. [PMID: 28782651 DOI: 10.1016/j.cmi.2017.07.028] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 06/07/2017] [Accepted: 07/04/2017] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Dalbavancin is a long-acting lipoglycopeptide with activity against gram-positives, including methicillin-resistant Staphylococcus aureus (MRSA). The potential for lipoglycopeptides, with half-lives greater than 1 week, to select for resistance is unknown. Here we explore a case of MRSA central line-associated bloodstream infection in which dalbavancin and vancomycin non-susceptibility emerged in a urine isolate collected after the patient was treated with vancomycin and dalbavancin sequentially. METHODS Isolates from blood and urine underwent susceptibility testing, and whole genome sequencing (WGS). The blood isolate was subjected to successive passage in vitro in the presence of escalating dalbavancin concentrations and the emergent isolate was subjected to repeat susceptibility testing and WGS. RESULTS The blood isolate was fully susceptible to vancomycin; however, MICs of the urine isolate to dalbavancin, vancomycin, telavancin, and daptomycin were at least fourfold higher than the blood-derived strain. Both strains were indistinguishable by spa and variable number tandem repeat (VNTR) typing, and WGS revealed only seven variants, indicating clonality. Four variants affected genes, including a 3bp in-frame deletion in yvqF, a gene which has been implicated in glycopeptide resistance. Vancomycin and dalbavancin non-susceptibility emerged in the blood isolate after successive passage in vitro in the presence of dalbavancin, and WGS identified a single non-synonymous variant in yvqF. CONCLUSIONS This is the first case in which VISA has emerged in the context of a dalbavancin-containing regimen. The selection for cross-resistance to vancomycin in vitro by dalbavancin exposure alone is troubling. Clinicians should be aware of the possibility for emergence of dalbavancin non-susceptibility and glycopeptide cross-resistance arising following therapy.
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Affiliation(s)
- B J Werth
- Department of Pharmacy, University of Washington School of Pharmacy, Seattle, WA, USA
| | - R Jain
- Department of Pharmacy, University of Washington School of Pharmacy, Seattle, WA, USA
| | - A Hahn
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, USA
| | - L Cummings
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA
| | - T Weaver
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA
| | - A Waalkes
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA
| | - D Sengupta
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA
| | - S J Salipante
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA
| | - R M Rakita
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, USA
| | - S M Butler-Wu
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA.
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Reduced Vancomycin Susceptibility of Methicillin-Susceptible Staphylococcus aureus Has No Significant Impact on Mortality but Results in an Increase in Complicated Infection. Antimicrob Agents Chemother 2017; 61:AAC.00316-17. [PMID: 28507105 DOI: 10.1128/aac.00316-17] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Accepted: 05/07/2017] [Indexed: 01/17/2023] Open
Abstract
Methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infections (BSIs) often lead to severe complications despite the availability of effective antibiotics. It remains unclear whether elevated vancomycin MICs are associated with worse outcomes. We conducted a 2-year retrospective cohort study (n = 252) of patients with MSSA BSIs at a tertiary care hospital. We defined reduced vancomycin susceptibility (RVS) as a Microscan MIC of 2 mg/liter. All strains were genotyped (spa) and assessed for agr functionality. Multivariable logistic regression models were used to examine the impact of RVS phenotype and strain genotype on 30-day all-cause mortality and complicated bacteremia (metastatic spread, endovascular infection, or duration ≥3 days). One-third of patients (84/252) were infected with RVS isolates. RVS Infections were more frequently associated with metastatic or embolic sites of infection (36% versus 17%, P < 0.001), and endovascular infection (26% versus 12%, P = 0.004). These infections occurred more often in patients with fewer underlying comorbidities (Charlson comorbidity index of ≥3 [73% versus 88%, P = 0.002]). Genotyping identified 127 spa-types and 14 Spa-clonal complexes (Spa-CCs). Spa-CC002 and Spa-CC008 were more likely to exhibit the RVS phenotype versus other Spa-CCs (OR = 2.2, P < 0.01). The RVS phenotype was not significantly associated with 30-day mortality; however, it was associated with complicated bacteremia (adjusted odds ratio of 2.35 [range, 1.26 to 4.37]; P = 0.007) in adjusted analyses. The association of RVS strains with complicated infection and fewer underlying comorbidities suggests the phenotype as a potential marker of strain virulence in MSSA BSIs. The RVS phenotype itself was not a significant predictor of mortality in this patient cohort. Further studies are necessary to explore this host-pathogen relationship.
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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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