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Giulieri SG, Guérillot R, Holmes NE, Baines SL, Hachani A, Hayes AS, Daniel DS, Seemann T, Davis JS, Van Hal S, Tong SYC, Stinear TP, Howden BP. A statistical genomics framework to trace bacterial genomic predictors of clinical outcomes in Staphylococcus aureus bacteremia. Cell Rep 2023; 42:113069. [PMID: 37703880 DOI: 10.1016/j.celrep.2023.113069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 06/29/2023] [Accepted: 08/18/2023] [Indexed: 09/15/2023] Open
Abstract
Outcomes of severe bacterial infections are determined by the interplay between host, pathogen, and treatments. While human genomics has provided insights into host factors impacting Staphylococcus aureus infections, comparatively little is known about S. aureus genotypes and disease severity. Building on the hypothesis that bacterial pathoadaptation is a key outcome driver, we developed a genome-wide association study (GWAS) framework to identify adaptive mutations associated with treatment failure and mortality in S. aureus bacteremia (1,358 episodes). Our research highlights the potential of vancomycin-selected mutations and vancomycin minimum inhibitory concentration (MIC) as key explanatory variables to predict infection severity. The contribution of bacterial variation was much lower for clinical outcomes (heritability <5%); however, GWASs allowed us to identify additional, MIC-independent candidate pathogenesis loci. Using supervised machine learning, we were able to quantify the predictive potential of these adaptive signatures. Our statistical genomics framework provides a powerful means to capture adaptive mutations impacting severe bacterial infections.
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Affiliation(s)
- Stefano G Giulieri
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia; Victorian Infectious Disease Service, The Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia; Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia; Department of Infectious Diseases, Austin Health, Heidelberg, VIC 3084, Australia.
| | - Romain Guérillot
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Natasha E Holmes
- Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia; Department of Infectious Diseases, Austin Health, Heidelberg, VIC 3084, Australia
| | - Sarah L Baines
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia; Centre for Pathogen Genomics, The University of Melbourne, Melbourne, VIC 3000, Australia
| | - Abderrahman Hachani
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Ashleigh S Hayes
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Diane S Daniel
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Torsten Seemann
- Centre for Pathogen Genomics, The University of Melbourne, Melbourne, VIC 3000, Australia
| | - Joshua S Davis
- Department of Infectious Diseases, John Hunter Hospital, New Lambton Heights, NSW 2305, Australia; Menzies School of Health Research, Charles Darwin University, Casuarina, NT 0810, Australia
| | - Sebastiaan Van Hal
- Department of Infectious Diseases and Microbiology, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia; Central Clinical School, University of Sydney, Camperdown, NSW 2050, Australia
| | - Steven Y C Tong
- Victorian Infectious Disease Service, The Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia; Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Timothy P Stinear
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Benjamin P Howden
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia; Department of Infectious Diseases, Austin Health, Heidelberg, VIC 3084, Australia; Centre for Pathogen Genomics, The University of Melbourne, Melbourne, VIC 3000, Australia
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Pajares-Chamorro N, Lensmire JM, Hammer ND, Hardy JW, Chatzistavrou X. Unraveling the mechanisms of inhibition of silver-doped bioactive glass-ceramic particles. J Biomed Mater Res A 2022; 111:975-994. [PMID: 36583930 DOI: 10.1002/jbm.a.37482] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 12/05/2022] [Accepted: 12/08/2022] [Indexed: 12/31/2022]
Abstract
Infections are a major concern in orthopedics. Antibacterial agents such as silver ions are of great interest as broad-spectrum biocides and have been incorporated into bioactive glass-ceramic particles to control the release of ions within a therapeutic concentration and provide tissue regenerative properties. In this work, the antibacterial capabilities of silver-doped bioactive glass (Ag-BG) microparticles were explored to reveal the unedited mechanisms of inhibition against methicillin-resistant Staphylococcus aureus (MRSA). The antibacterial properties were not limited to the delivery of silver ions but rather a combination of antibacterial degradation by-products. For example, nano-sized debris punctured holes in bacteria membranes, osmotic effects, and reactive oxygen species causing oxidative stress and almost 40% of the inhibition. Upon successive Ag-BG treatments, MRSA underwent phenotypic and genomic mutations which were not only insufficient to develop resistance but instead, the clones became more sensitive as the treatment was re-delivered. Additionally, the unprecedented restorative functionality of Ag-BG allowed the effective use of antibiotics that MRSA resists. The synergy mechanism was mainly identified for combinations targeting cell-wall activity and their action was proven in biofilm-like and virulent conditions. Unraveling these mechanisms may offer new insights into how to tailor healthcare materials to prevent or debilitate infections and join the fight against antibiotic resistance in clinical cases.
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Affiliation(s)
- Natalia Pajares-Chamorro
- Department of Chemical Engineering and Material Science, College of Engineering, Michigan State University, East Lansing, Michigan, USA
| | - Josh M Lensmire
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Neal D Hammer
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Jonathan W Hardy
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA.,Institute for Quantitative Health Science and Engineering (IQ), Michigan State University, East Lansing, Michigan, USA
| | - Xanthippi Chatzistavrou
- Department of Chemical Engineering and Material Science, College of Engineering, Michigan State University, East Lansing, Michigan, USA.,Department of Chemical Engineering, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Transcriptomic and Metabolomic Analysis of a Fusidic Acid-Selected fusA Mutant of Staphylococcus aureus. Antibiotics (Basel) 2022; 11:antibiotics11081051. [PMID: 36009920 PMCID: PMC9405211 DOI: 10.3390/antibiotics11081051] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 11/17/2022] Open
Abstract
Physiological experimentation, transcriptomics, and metabolomics were engaged to compare a fusidic acid-resistant Staphylococcus aureus mutant SH10001st-2 to its parent strain SH1000. SH10001st-2 harbored a mutation (H457Y) in the gene fusA which encodes the fusidic acid target, elongation factor G, as well as mutations in a putative phage gene of unknown function. SH10001st-2 grew slower than SH1000 at three temperatures and had reduced coagulase activity, two indicators of the fitness penalty reported for fusA-mediated fusidic acid- resistance in the absence of compensatory mutations. Despite the difference in growth rates, the levels of O2 consumption and CO2 production were comparable. Transcriptomic profiling revealed 326 genes were upregulated and 287 were downregulated in SH10001st-2 compared to SH1000. Cell envelope and transport and binding protein genes were the predominant functional categories of both upregulated and downregulated genes in SH10001st-2. Genes of virulence regulators, notably the agr and kdp systems, were highly upregulated as were genes encoding capsule production. Contrary to what is expected of mid-exponential phase cells, genes encoding secreted virulence factors were generally upregulated while those for adhesion-associated virulence factors were downregulated in SH10001st-2. Metabolomic analysis showed an overall increase in metabolite pools in SH10001st-2 compared to SH1000, mostly for amino acids and sugars. Slowed growth and metabolite accumulation may be byproducts of fusA mutation-mediated protein synthesis impairment, but the overall results indicate that SH10001st-2 is compensating for the H457Y fitness penalty by repurposing its virulence machinery, in conjunction with increasing metabolite uptake capacity, in order to increase nutrient acquisition.
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Turner AB, Gerner E, Firdaus R, Echeverz M, Werthén M, Thomsen P, Almqvist S, Trobos M. Role of sodium salicylate in Staphylococcus aureus quorum sensing, virulence, biofilm formation and antimicrobial susceptibility. Front Microbiol 2022; 13:931839. [PMID: 35992652 PMCID: PMC9384861 DOI: 10.3389/fmicb.2022.931839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/06/2022] [Indexed: 01/01/2023] Open
Abstract
The widespread threat of antibiotic resistance requires new treatment options. Disrupting bacterial communication, quorum sensing (QS), has the potential to reduce pathogenesis by decreasing bacterial virulence. The aim of this study was to investigate the influence of sodium salicylate (NaSa) on Staphylococcus aureus QS, virulence production and biofilm formation. In S. aureus ATCC 25923 (agr III), with or without serum, NaSa (10 mM) downregulated the agr QS system and decreased the secretion levels of alpha-hemolysin, staphopain A and delta-hemolysin. Inhibition of agr expression caused a downregulation of delta-hemolysin, decreasing biofilm dispersal and increasing biofilm formation on polystyrene and titanium under static conditions. In contrast, NaSa did not increase biofilm biomass under flow but caused one log10 reduction in biofilm viability on polystyrene pegs, resulting in biofilms being twice as susceptible to rifampicin. A concentration-dependent effect of NaSa was further observed, where high concentrations (10 mM) decreased agr expression, while low concentrations (≤0.1 mM) increased agr expression. In S. aureus 8325-4 (agr I), a high concentration of NaSa (10 mM) decreased hla expression, and a low concentration of NaSa (≤1 mM) increased rnaIII and hla expression. The activity of NaSa on biofilm formation was dependent on agr type and material surface. Eight clinical strains isolated from prosthetic joint infection (PJI) or wound infection belonging to each of the four agr types were evaluated. The four PJI S. aureus strains did not change their biofilm phenotype with NaSa on the clinically relevant titanium surface. Half of the wound strains (agr III and IV) did not change the biofilm phenotype in the 3D collagen wound model. In addition, compared to the control, ATCC 25923 biofilms formed with 10 mM NaSa in the collagen model were more susceptible to silver. It is concluded that NaSa can inhibit QS in S. aureus, decreasing the levels of toxin production with certain modulation of biofilm formation. The effect on biofilm formation was dependent on the strain and material surface. It is suggested that the observed NaSa inhibition of bacterial communication is a potential alternative or adjuvant to traditional antibiotics.
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Affiliation(s)
- Adam Benedict Turner
- Department of Biomaterials, University of Gothenburg, The Sahlgrenska Academy, Gothenburg, Sweden
- Center for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Erik Gerner
- Department of Biomaterials, University of Gothenburg, The Sahlgrenska Academy, Gothenburg, Sweden
- Center for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
- Mölnlycke Health Care AB, Gothenburg, Sweden
| | - Rininta Firdaus
- Department of Biomaterials, University of Gothenburg, The Sahlgrenska Academy, Gothenburg, Sweden
- Center for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Maite Echeverz
- Microbial Pathogenesis Research Unit, Public University of Navarre, Pamplona, Spain
| | - Maria Werthén
- Department of Biomaterials, University of Gothenburg, The Sahlgrenska Academy, Gothenburg, Sweden
- Center for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Peter Thomsen
- Department of Biomaterials, University of Gothenburg, The Sahlgrenska Academy, Gothenburg, Sweden
| | | | - Margarita Trobos
- Department of Biomaterials, University of Gothenburg, The Sahlgrenska Academy, Gothenburg, Sweden
- Center for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
- *Correspondence: Margarita Trobos,
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5
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Wang Y, Lu J, Zhang S, Li J, Mao L, Yuan Z, Bond PL, Guo J. Non-antibiotic pharmaceuticals promote the transmission of multidrug resistance plasmids through intra- and intergenera conjugation. THE ISME JOURNAL 2021; 15:2493-2508. [PMID: 33692486 PMCID: PMC8397710 DOI: 10.1038/s41396-021-00945-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 02/14/2021] [Accepted: 02/18/2021] [Indexed: 12/30/2022]
Abstract
Antibiotic resistance is a global threat to public health. The use of antibiotics at sub-inhibitory concentrations has been recognized as an important factor in disseminating antibiotic resistance via horizontal gene transfer. Although non-antibiotic, human-targeted pharmaceuticals are widely used by society (95% of the pharmaceuticals market), the potential contribution to the spread of antibiotic resistance is not clear. Here, we report that commonly consumed, non-antibiotic pharmaceuticals, including nonsteroidal anti-inflammatories (ibuprofen, naproxen, diclofenac), a lipid-lowering drug (gemfibrozil), and a β-blocker (propranolol), at clinically and environmentally relevant concentrations, significantly accelerated the dissemination of antibiotic resistance via plasmid-borne bacterial conjugation. Various indicators were used to study the bacterial response to these drugs, including monitoring reactive oxygen species (ROS) and cell membrane permeability by flow cytometry, cell arrangement, and whole-genome RNA and protein sequencing. Enhanced conjugation correlated well with increased production of ROS and cell membrane permeability. Additionally, these non-antibiotic pharmaceuticals induced responses similar to those detected when bacteria are exposed to antibiotics, such as inducing the SOS response and enhancing efflux pumps. The findings advance understanding of the transfer of antibiotic resistance genes, emphasizing the concern that non-antibiotic, human-targeted pharmaceuticals enhance the spread of antibiotic resistance among bacterial populations.
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Affiliation(s)
- Yue Wang
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD, Australia
| | - Ji Lu
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD, Australia
| | - Shuai Zhang
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD, Australia
| | - Jie Li
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD, Australia
| | - Likai Mao
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD, Australia
| | - Philip L Bond
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD, Australia
| | - Jianhua Guo
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD, Australia.
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Rivera AJ, Tyx RE. Microbiology of the American Smokeless Tobacco. Appl Microbiol Biotechnol 2021; 105:4843-4853. [PMID: 34110473 PMCID: PMC8190171 DOI: 10.1007/s00253-021-11382-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/17/2021] [Accepted: 05/28/2021] [Indexed: 12/23/2022]
Abstract
Smokeless tobacco products (STP) contain diverse microbial communities that contribute to the formation of harmful chemical byproducts. This is concerning since 300 million individuals around the globe are users of smokeless tobacco. Significant evidence has shown that microbial metabolic activities mediate the formation of carcinogens during manufacturing. In recent years, studies have revealed a series of additional health impacts that include lesions and inflammation of the oral mucosa and the gastrointestinal tract, as well as alterations of the endogenous microbiota. These findings are due to recent developments in molecular technologies that allowed researchers to better examine the microbial component of these products. This new information illustrates the scale of the STP microbiota and its diversity in the finished product that is sold for consumption. Additionally, the application of metagenomics and metatranscriptomics has provided the tools to look at phylogenies across bacterial, viral, and eukaryotic groups, their functional capacities, and viability. Here we present key examples of tobacco microbiology research that utilizes newer approaches and strategies to define the microbial component of smokeless tobacco products. We also highlight challenges in these approaches, the knowledge gaps being filled, and those gaps that warrant further study. A better understanding of the microbiology of STP brings vast public health benefits. It will provide important information for the product consumer, impact manufacturing practices, and provide support for the development of attainable and more meaningful regulatory goals. KEY POINTS: Newer technologies allowed quicker and more comprehensive identification of microbes in tobacco samples, encapsulating microorganisms difficult or impossible to culture. Current research in smokeless tobacco microbiology is filling knowledge gaps previously unfilled due to the lack of suitable approaches. The microbial ecology of smokeless tobacco presents a clearer picture of diversity and variability not considered before.
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Affiliation(s)
- A J Rivera
- Centers for Disease Control and Prevention, 4770 Buford Highway, NE M.S. S110-03, Atlanta, GA, 30341-3717, USA.
| | - R E Tyx
- Centers for Disease Control and Prevention, 4770 Buford Highway, NE M.S. S110-03, Atlanta, GA, 30341-3717, USA
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Apt (Adenine Phosphoribosyltransferase) Mutation in Laboratory-Selected Vancomycin-Intermediate Staphylococcus aureus. Antibiotics (Basel) 2021; 10:antibiotics10050583. [PMID: 34069103 PMCID: PMC8170892 DOI: 10.3390/antibiotics10050583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/19/2021] [Accepted: 04/27/2021] [Indexed: 11/16/2022] Open
Abstract
Comparative genomic sequencing of laboratory-derived vancomycin-intermediate Staphylococcusaureus (VISA) (MM66-3 and MM66-4) revealed unique mutations in both MM66-3 (in apt and ssaA6), and MM66-4 (in apt and walK), compared to hetero-VISA parent strain MM66. Transcriptional profiling revealed that both MM66 VISA shared 79 upregulated genes and eight downregulated genes. Of these, 30.4% of the upregulated genes were associated with the cell envelope, whereas 75% of the downregulated genes were associated with virulence. In concordance with mutations and transcriptome alterations, both VISA strains demonstrated reduced autolysis, reduced growth in the presence of salt and reduced virulence factor activity. In addition to mutations in genes linked to cell wall metabolism (ssaA6 and walK), the same mutation in apt which encodes adenine phosphoribosyltransferase, was confirmed in both MM66 VISA. Apt plays a role in both adenine metabolism and accumulation and both MM66 VISA grew better than MM66 in the presence of adenine or 2-fluoroadenine indicating a reduction in the accumulation of these growth inhibiting compounds in the VISA strains. MM66 apt mutants isolated via 2-fluoroadenine selection also demonstrated reduced susceptibility to the cell wall lytic dye Congo red and vancomycin. Finding that apt mutations contribute to reduced vancomycin susceptibility once again suggests a role for altered purine metabolism in a VISA mechanism.
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Öztürk İ, Eraç Y, Ballar Kırmızibayrak P, Ermertcan Ş. Nonsteroidal antiinflammatory drugs alter antibiotic susceptibility and expression of virulence-related genes and protein A of Staphylococcus aureus. Turk J Med Sci 2021; 51:835-847. [PMID: 33078603 PMCID: PMC8203164 DOI: 10.3906/sag-2003-60] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 10/20/2020] [Indexed: 11/26/2022] Open
Abstract
Background/aim Nonsteroidal antiinflammatory drugs (NSAIDs) including diclofenac, naproxen, ibuprofen, acetylsalicylic acid, and acetaminophen have been shown to have antimicrobial effects on various microorganisms. The aim of this study was to investigate the antibacterial effects of NSAIDs on
Staphylococcus aureus
. Materials and methods Susceptibilities of
S. aureus
strains to NSAIDs with or without antimicrobials (moxifloxacin, vancomycin, ciprofloxacin, clindamycin, and gentamicin) were determined using the microdilution method and disk diffusion test. Expression levels of genes in the presence of drugs were investigated by real-time quantitative RT-PCR (qRT-PCR), and immunoblotting analysis was performed for staphylococcal protein A (SpA). Results Our results showed that all NSAIDs were active against
S. aureus
strains with MIC values ranging from 195 µg/mL to 6250 µg/mL. NSAIDs increased the antibiotic susceptibility of the strains, and diclofenac was found to be more effective than the other drugs. Drugs showed different effects on expression levels of virulence factor and/or regulatory genes. Immunoblotting analysis of SpA protein was mostly in accordance with qRT-PCR results. Conclusion The regulatory/virulence factor genes and proteins of
S. aureus
investigated in this study may be reasonable targets for these drugs, and we suggest that the data may contribute to the field of infection control and antimicrobial resistance.
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Affiliation(s)
- İsmail Öztürk
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, İzmir Katip Çelebi University, İzmir, Turkey
| | - Yasemin Eraç
- Department of Pharmacology, Faculty of Pharmacy, Ege University, İzmir, Turkey
| | | | - Şafak Ermertcan
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Ege University, İzmir, Turkey
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Dotto C, Lombarte Serrat A, Ledesma M, Vay C, Ehling-Schulz M, Sordelli DO, Grunert T, Buzzola F. Salicylic acid stabilizes Staphylococcus aureus biofilm by impairing the agr quorum-sensing system. Sci Rep 2021; 11:2953. [PMID: 33536503 PMCID: PMC7858585 DOI: 10.1038/s41598-021-82308-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 01/19/2021] [Indexed: 01/30/2023] Open
Abstract
Salicylic acid (SAL) has recently been shown to induce biofilm formation in Staphylococcus aureus and to affect the expression of virulence factors. This study was aimed to investigate the effect of SAL on the regulatory agr system and its impact on S. aureus biofilm formation. The agr quorum-sensing system, which is a central regulator in S. aureus pathogenicity, plays a pivotal role in the dispersal of S. aureus mature biofilms and contributes to the creation of new colonization sites. Here, we demonstrate that SAL impairs biofilm dispersal by interfering with agr expression. As revealed by our work, protease and surfactant molecule production is diminished, and bacterial cell autolysis is also negatively affected by SAL. Furthermore, as a consequence of SAL treatment, the S. aureus biofilm matrix revealed the lack of extracellular DNA. In silico docking and simulation of molecular dynamics provided evidence for a potential interaction of AgrA and SAL, resulting in reduced activity of the agr system. In conclusion, SAL stabilized the mature S. aureus biofilms, which may prevent bacterial cell dissemination. However, it may foster the establishment of infections locally and consequently increase bacterial persistence leading to therapeutic failure.
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Affiliation(s)
- Cristian Dotto
- Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
- Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), CONICET, Buenos Aires, Argentina
| | - Andrea Lombarte Serrat
- Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
- Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Martín Ledesma
- Instituto de Fisiopatología y Bioquímica Clínica (INFIBIOC), Facultad de Farmacia y Bioquímica, Hospital de Clínicas José de San Martín, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Carlos Vay
- Instituto de Fisiopatología y Bioquímica Clínica (INFIBIOC), Facultad de Farmacia y Bioquímica, Hospital de Clínicas José de San Martín, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Monika Ehling-Schulz
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
| | - Daniel O Sordelli
- Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
- Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Tom Grunert
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
| | - Fernanda Buzzola
- Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina.
- Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
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Kitichalermkiat A, Katsuki M, Sato J, Sonoda T, Masuda Y, Honjoh KI, Miyamoto T. Effect of epigallocatechin gallate on gene expression of Staphylococcus aureus. J Glob Antimicrob Resist 2020; 22:854-859. [DOI: 10.1016/j.jgar.2020.06.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 04/26/2020] [Accepted: 06/08/2020] [Indexed: 12/12/2022] Open
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Blaskovich MAT, Elliott AG, Kavanagh AM, Ramu S, Cooper MA. In vitro Antimicrobial Activity of Acne Drugs Against Skin-Associated Bacteria. Sci Rep 2019; 9:14658. [PMID: 31601845 PMCID: PMC6787063 DOI: 10.1038/s41598-019-50746-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 09/12/2019] [Indexed: 01/07/2023] Open
Abstract
Acne is a common skin affliction that involves excess sebum production and modified lipid composition, duct blockage, colonization by bacteria, and inflammation. Acne drugs target one or more of these steps, with antibiotics commonly used to treat the microbial infection for moderate to severe cases. Whilst a number of other acne therapies are purported to possess antimicrobial activity, this has been poorly documented in many cases. We conducted a comparative analysis of the activity of common topical acne drugs against the principal etiological agent associated with acne: the aerotolerant anaerobic Gram-positive organism Propionibacterium acnes (recently renamed as Cutibacterium acnes). We also assessed their impact on other bacteria that could also be affected by topical treatments, including both antibiotic-sensitive and antibiotic-resistant strains, using broth microdilution assay conditions. Drugs designated specifically as antibiotics had the greatest potency, but lost activity against resistant strains. The non-antibiotic acne agents did possess widespread antimicrobial activity, including against resistant strains, but at substantially higher concentrations. Hence, the antimicrobial activity of non-antibiotic acne agents may provide protection against a background of increased drug-resistant bacteria.
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Affiliation(s)
- Mark A T Blaskovich
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia.
| | - Alysha G Elliott
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Angela M Kavanagh
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Soumya Ramu
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Matthew A Cooper
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia
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Dupre JM, Johnson WL, Ulanov AV, Li Z, Wilkinson BJ, Gustafson JE. Transcriptional profiling and metabolomic analysis of Staphylococcus aureus grown on autoclaved chicken breast. Food Microbiol 2019; 82:46-52. [DOI: 10.1016/j.fm.2019.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 12/21/2018] [Accepted: 01/11/2019] [Indexed: 10/27/2022]
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13
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Wang H, Kraus F, Popella P, Baykal A, Guttroff C, François P, Sass P, Plietker B, Götz F. The Polycyclic Polyprenylated Acylphloroglucinol Antibiotic PPAP 23 Targets the Membrane and Iron Metabolism in Staphylococcus aureus. Front Microbiol 2019; 10:14. [PMID: 30728811 PMCID: PMC6352742 DOI: 10.3389/fmicb.2019.00014] [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] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 01/07/2019] [Indexed: 11/13/2022] Open
Abstract
Recently, a series of endo-type B polycyclic polyprenylated acylphloroglucinols (PPAP) derivatives with high antimicrobial activities were chemically synthesized. One of the derivatives, PPAP 23, which showed high antimicrobial activity and low cytotoxicity, was chosen for further investigation of its bactericidal profiles and mode of action. PPAP 23 showed a better efficacy in killing methicillin resistant Staphylococcus aureus (MRSA) and decreasing the metabolic activity of 5-day-old biofilm cells than vancomycin. Moreover, S. aureus did not appear to develop resistance against PPAP 23. The antimicrobial mechanism of PPAP 23 was investigated by RNA-seq combined with phenotypic and biochemical approaches. RNA-seq suggested that PPAP 23 signaled iron overload to the bacterial cells because genes involved in iron transport were downregulated and iron storage gene was upregulated by PPAP 23. PPAP 23 affected the membrane integrity but did not induce pore formation; it inhibited bacterial respiration. PPAP 23 preferentially inhibited Fe–S cluster enzymes; it has a mild iron chelating activity and supplementation of exogenous iron attenuated its antimicrobial activity. PPAP 23 was more effective in inhibiting the growth of S. aureus under iron-restricted condition. The crystal structure of a benzylated analog of PPAP 23 showed a highly defined octahedral coordination of three PPAP ligands around a Fe (3+) core. This suggests that PPAPs are generally capable of iron chelation and are able to form defined stable complexes. PPAP 23 was found to induce reactive oxygen species (ROS) and oxidative stress. Fluorescence microscopic analysis showed that PPAP 23 caused an enlargement of the bacterial cells, perturbed the membrane, and dislocated the nucleoid. Taken together, we postulate that PPAP 23 interacts with the cytoplasmic membrane with its hydrophobic pocket and interferes with the iron metabolism to exert its antimicrobial activity in Staphylococcus aureus.
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Affiliation(s)
- Huanhuan Wang
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), University of Tübingen, Tübingen, Germany
| | - Frank Kraus
- Institut für Organische Chemie, Universität Stuttgart, Stuttgart, Germany
| | - Peter Popella
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), University of Tübingen, Tübingen, Germany
| | - Aslihan Baykal
- Institut für Organische Chemie, Universität Stuttgart, Stuttgart, Germany
| | - Claudia Guttroff
- Institut für Organische Chemie, Universität Stuttgart, Stuttgart, Germany
| | - Patrice François
- Genomic Research Laboratory, Division of Infectious Diseases, Geneva University Hospital, Geneva, Switzerland
| | - Peter Sass
- Microbial Bioactive Compounds, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), University of Tübingen, Tübingen, Germany
| | - Bernd Plietker
- Institut für Organische Chemie, Universität Stuttgart, Stuttgart, Germany
| | - Friedrich Götz
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), University of Tübingen, Tübingen, Germany
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Abstract
INTRODUCTION Aspirin (acetylsalicylic acid, ASA) is often co-administered during the treatment of infections. Salicylic acid (SAL), the active metabolite of ASA, has significant effects on bacteria that might improve or (more likely) compromise the effectiveness of antibiotics. Areas covered: In this review, we summarize the interactions between SAL and antibiotics, and describe the underlying mechanisms involved. Expert opinion: In an era of rapidly increasing antibiotic resistance and lack of new antibiotic development, it is important to explore ways to optimize the effectiveness of antimicrobial treatment. This includes a better understanding of the interactions between commonly co-administered drugs. SAL might compromise the effectiveness of antibiotic treatment by inducing phenotypic resistance in bacteria. It can induce phenotypic resistance by up- or downregulating outer membrane proteins or efflux pumps, by upregulating antibiotic targets and by inducing enzymes with degrading activity. Moreover, SAL can increase the frequency of mutations leading to antibiotic resistance.
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Affiliation(s)
- Petra Zimmermann
- a Department of Paediatrics , The University of Melbourne , Parkville , Australia.,b Infectious Diseases & Microbiology Research Group , Murdoch Children's Research Institute , Parkville , Australia.,c Infectious Diseases Unit , The Royal Children's Hospital Melbourne , Parkville , Australia.,d Infectious Diseases Unit , University of Basel Children's Hospital , Basel , Switzerland
| | - Nigel Curtis
- a Department of Paediatrics , The University of Melbourne , Parkville , Australia.,b Infectious Diseases & Microbiology Research Group , Murdoch Children's Research Institute , Parkville , Australia.,c Infectious Diseases Unit , The Royal Children's Hospital Melbourne , Parkville , Australia
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15
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Complex gene response of herbicide-resistant Enterobacter strain NRS-1 under different glyphosate stresses. 3 Biotech 2018; 8:422. [PMID: 30305993 DOI: 10.1007/s13205-018-1455-0] [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: 07/27/2018] [Accepted: 09/24/2018] [Indexed: 10/28/2022] Open
Abstract
Knowledge of biological evolution and genetic mechanisms is gained by studying the adaptation of bacteria to survive in adverse environmental conditions. In this regard, transcriptomic profiling of a glyphosate-tolerant Enterobacter strain NRS-1 was studied under four different treatments to investigate the gene-regulatory system for glyphosate tolerance. A total of 83, 83, 60 and 74 genes were up-regulated and 108, 87, 178 and 117 genes down-regulated under 60-NPG, 110-NPG, NaCl (355 mM) and HCl (pH 4.46) stress treatments, respectively. Complex gene network was identified to be involved in regulating tolerance to glyphosate. This study revealed that NRS-1 has gained glyphosate tolerance at the cost of osmotic and acidic resistance. The 25 differentially expressed genes are reported to may have partly changed the function for providing resistance to glyphosate directly, among them genes metK, mtbK, fdnG and wzb that might detoxify/degrade the glyphosate. However, under 110-NPG condition, NRS-1 might have utilized economical and efficient ways by depressing its metabolism and activity to pass through this stress. Hence, the present study provides insights into the genes involved in glyphosate tolerance, which can be effectively utilized to engineer herbicide-resistant crop varieties after their proper validation to manage weed growth.
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16
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Cai JY, Wang YY, Ma K, Hou YN, Yao GD, Hayashi T, Itoh K, Tashiro SI, Onodera S, Ikejima T. Salicylate induces reactive oxygen species and reduces ultraviolet C susceptibility in Staphylococcus aureus. FEMS Microbiol Lett 2018; 365:4931717. [PMID: 29546276 DOI: 10.1093/femsle/fny056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 03/06/2018] [Indexed: 11/13/2022] Open
Abstract
This study demonstrates that growth of Staphylococcus aureus in the presence of salicylate reduces ultraviolet C (UVC)-induced cell death and increases the generation of reactive oxygen species (ROS). In addition, compounds that scavenge ROS (N-acetylcysteine, glutathione, catalase and superoxide dismutase) reverse the increased UVC survival induced by growth in the presence of salicylate, while ROS donors (tert-butylhydroperoxide, H2O2 and NaClO) enhance survival of salicylate challenged cultures. Collectively, these findings suggest that ROS production induced by growth in the presence of salicylate protects S. aureus from UVC-induced cell death.
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Affiliation(s)
- Jia-Yi Cai
- China-Japan Research Institute of Medical and Pharmaceutical Sciences, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Yuan-Yuan Wang
- China-Japan Research Institute of Medical and Pharmaceutical Sciences, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, China.,Department of Drug Discover and Development, Shanghai FrontHealth Pharmaceutical Technology Company, Shanghai 201203, China
| | - Kai Ma
- China-Japan Research Institute of Medical and Pharmaceutical Sciences, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Yong-Na Hou
- China-Japan Research Institute of Medical and Pharmaceutical Sciences, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Guo-Dong Yao
- School of Traditional Chinese Materia Medica, Key Laboratory of Structure-Based Drug Design & Discovery (Ministry of Education), Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Toshihiko Hayashi
- China-Japan Research Institute of Medical and Pharmaceutical Sciences, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Kikuji Itoh
- Biochemical Center, Japan SLC, Inc., Shizuoka 431-1103, Japan
| | - Shin-Ichi Tashiro
- Department of Medical Education & Primary Care, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Satoshi Onodera
- Department of Clinical and Pharmaceutical Sciences, Showa Pharmaceutical University, Tokyo 194-8543, Japan
| | - Takashi Ikejima
- China-Japan Research Institute of Medical and Pharmaceutical Sciences, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, China
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17
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Choi KM, Kim MH, Cai H, Lee YJ, Hong Y, Ryu PY. Salicylic Acid Reduces OmpF Expression, Rendering Salmonella enterica Serovar Typhimurium More Resistant to Cephalosporin Antibiotics. Chonnam Med J 2018; 54:17-23. [PMID: 29399561 PMCID: PMC5794474 DOI: 10.4068/cmj.2018.54.1.17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 01/18/2018] [Accepted: 01/19/2018] [Indexed: 11/06/2022] Open
Abstract
Salmonella enterica serovar Typhimurium is one of the most important bacterial pathogens causing diarrhea. The resistance of S. typhimurium to antimicrobial agents, which has recently been isolated from patients, is causing serious problems. We investigated the effects of salicylic acid (Sal) and acetyl salicylate (AcSal) on the susceptibility of S. typhimurium to cephalosporin antibiotics, which are known to increase resistance to cephalosporin and quinolone antibiotics. The MIC of cephalosporin antibiotics was higher than that of the media without Sal. The rate of accumulation of ethidium bromide (EtBr) in the bacteria by the outer membrane protein (Omp) was not different from that of the bacteria cultured in the medium containing Sal. However, Carbonyl cyanide-m-chlorophenylhydrazone (CCCP), an inhibitor of bacterial efflux pumps, significantly reduced the rate of accumulation of EtBr in bacteria cultured on Sal containing medium. In the medium containing CCCP, the MIC of the antimicrobial agent tended to decrease as compared with the control. In addition, the MIC of the bacteria treated with CCCP and Sal was higher than that of the antimicrobial agent against the CCCP treated experimental bacteria. These results suggest that Sal decreases the expression of OmpF in the Omp of S. typhimurium and reduces the permeability of cephalosporin antibiotics to bacteria, which may induce tolerance to cephalosporin antibiotics.
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Affiliation(s)
- Kyung Min Choi
- Department of Microbiology and Immunology, Chonnam National University Medical School, Gwangju, Korea
| | - Mi Hyun Kim
- Department of Microbiology and Immunology, Chonnam National University Medical School, Gwangju, Korea.,Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Hua Cai
- Department of Microbiology and Immunology, Chonnam National University Medical School, Gwangju, Korea
| | - Yong Jin Lee
- Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Yeongjin Hong
- Department of Microbiology and Immunology, Chonnam National University Medical School, Gwangju, Korea
| | - Phil Youl Ryu
- Department of Microbiology and Immunology, Chonnam National University Medical School, Gwangju, Korea
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18
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Pando JM, Pfeltz RF, Cuaron JA, Nagarajan V, Mishra MN, Torres NJ, Elasri MO, Wilkinson BJ, Gustafson JE. Ethanol-induced stress response of Staphylococcus aureus. Can J Microbiol 2017; 63:745-757. [PMID: 28521110 DOI: 10.1139/cjm-2017-0221] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Transcriptional profiles of 2 unrelated clinical methicillin-resistant Staphylococcus aureus (MRSA) isolates were analyzed following 10% (v/v) ethanol challenge (15 min), which arrested growth but did not reduce viability. Ethanol-induced stress (EIS) resulted in differential gene expression of 1091 genes, 600 common to both strains, of which 291 were upregulated. With the exception of the downregulation of genes involved with osmotic stress functions, EIS resulted in the upregulation of genes that contribute to stress response networks, notably those altered by oxidative stress, protein quality control in general, and heat shock in particular. In addition, genes involved with transcription, translation, and nucleotide biosynthesis were downregulated. relP, which encodes a small alarmone synthetase (RelP), was highly upregulated in both MRSA strains following ethanol challenge, and relP inactivation experiments indicated that this gene contributed to EIS growth arrest. A number of persistence-associated genes were also upregulated during EIS, including those that encode toxin-antitoxin systems. Overall, transcriptional profiling indicated that the MRSA investigated responded to EIS by entering a state of dormancy and by altering the expression of elements from cross protective stress response systems in an effort to protect preexisting proteins.
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Affiliation(s)
- Jasmine M Pando
- a Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA
| | - Richard F Pfeltz
- b BD Diagnostic Systems, Microbiology R&D Department, Sparks, MD 21152, USA
| | - Jesus A Cuaron
- a Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA
| | - Vijayaraj Nagarajan
- c Department of Biological Sciences, University of Southern Mississippi, Hattiesburg, MS 39406, USA
| | - Mukti N Mishra
- d Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Nathanial J Torres
- d Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Mohamed O Elasri
- c Department of Biological Sciences, University of Southern Mississippi, Hattiesburg, MS 39406, USA
| | - Brian J Wilkinson
- e Microbiology Group, School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - John E Gustafson
- a Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA.,d Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
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19
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Vandevelde NM, Tulkens PM, Van Bambeke F. Modulating antibiotic activity towards respiratory bacterial pathogens by co-medications: a multi-target approach. Drug Discov Today 2016; 21:1114-29. [PMID: 27094105 DOI: 10.1016/j.drudis.2016.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 03/17/2016] [Accepted: 04/05/2016] [Indexed: 01/01/2023]
Abstract
Non-antibiotic drugs can modulate bacterial physiology and/or antibiotic activity, opening perspectives for innovative therapeutic strategies. Focusing on respiratory pathogens and considering in vitro, in vivo, and clinical data, here we examine the effect of these drugs on the expression of resistance mechanisms, biofilm formation, and intracellular survival, as well as their influence on the activity of antibiotics on bacteria. Beyond the description of the effects observed, we also comment on concentrations that are active and discuss the mechanisms of drug-drug or drug-target interactions. This discussion should be helpful in defining useful targets for adjuvant therapy and establishing the corresponding pharmacophores for further drug fine-tuning.
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Affiliation(s)
- Nathalie M Vandevelde
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Paul M Tulkens
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Françoise Van Bambeke
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
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20
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Zheng W, Liang Y, Zhao H, Zhang J, Li Z. 5,5'-Methylenedisalicylic Acid (MDSA) Modulates SarA/MgrA Phosphorylation by Targeting Ser/Thr Phosphatase Stp1. Chembiochem 2015; 16:1035-40. [PMID: 25810089 DOI: 10.1002/cbic.201500003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Indexed: 11/07/2022]
Abstract
SarA (staphylococcal accessory protein A), MgrA (MarR family of global transcriptional regulator A), and SarZ (a paralogue of SarA) play critical roles in modulating the virulence, drug resistance and autolysis of Staphylococcus aureus. Recently, eukaryotic-like Ser/Thr kinase/phosphatases (Stk1/Stp1) were found to modulate phosphorylation of these transcriptional regulators as well as staphylococcal virulence. Importantly, an stp1-deficient strain showed significant virulence reduction in mice, indicative of Stp1 as a potential drug target. Here, we report that MDSA, an inhibitor of MgrA, enhances phosphorylation of SarA/MgrA by inhibiting Stp1 in S. aureus. MDSA is a more-potent inhibitor (IC50 =9.68 ± 0.52 μM) of Stp1 than commonly used phosphatase inhibitors. We anticipate that MDSA could be a lead compound to develop new approaches for reducing staph virulence by targeting Stp1.
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Affiliation(s)
- Weihao Zheng
- Key Lab of Chemical Genomics, School of Chemical Biology and Biotechnology, Shenzhen Graduate School, Peking University, Shenzhen 518055 (China)
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21
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Cuaron JA, Dulal S, Cooke PH, Torres N, Gustafson JE. The isolation of Staphylococcus aureus tea tree oil-reduced susceptibility mutants. Phytother Res 2014; 28:1240-5. [PMID: 24519735 PMCID: PMC4125540 DOI: 10.1002/ptr.5123] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 12/20/2013] [Accepted: 01/06/2014] [Indexed: 11/09/2022]
Abstract
Tea tree oil (TTO)-reduced susceptibility (TTORS) mutants of two Staphylococcus aureus laboratory strains were isolated utilizing TTO gradient plates. Attempts to isolate TTORS mutants employing agar plates containing single TTO concentrations failed. All TTORS mutants demonstrated a small colony variant (SCV) phenotype and produced cells with a smaller diameter, as determined by scanning electron microscopy. The addition of SCV auxotrophic supplements to media did not lead to an increase in TTORS mutant colony size. Revertants were also isolated from the TTORS mutants following growth in drug-free media, and all revertant strains demonstrated phenotypes similar to their respective parent strains. Transmission electron microscopy revealed that an SH1000 TTORS mutant demonstrated a thinner cell wall and novel septal invaginations compared with parent strain SH1000. In addition, comparative genomic sequencing did not reveal any mutations in an SH1000 TTORS mutant previously linked to well-characterized SCV genotypes. This study demonstrates that TTO can select for a unique SCV phenotype.
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Affiliation(s)
- Jesus A. Cuaron
- Microbiology Group, Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA
| | - Santosh Dulal
- Microbiology Group, Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA
| | - Peter H. Cooke
- Core University Research Resources Laboratory, New Mexico State University, Las Cruces, NM 88003, USA
| | - Nathaniel Torres
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - John E. Gustafson
- Microbiology Group, Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
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23
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Cuaron JA, Dulal S, Song Y, Singh AK, Montelongo CE, Yu W, Nagarajan V, Jayaswal RK, Wilkinson BJ, Gustafson JE. Tea tree oil-induced transcriptional alterations in Staphylococcus aureus. Phytother Res 2012; 27:390-6. [PMID: 22619070 DOI: 10.1002/ptr.4738] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 04/18/2012] [Accepted: 04/22/2012] [Indexed: 11/09/2022]
Abstract
Tea tree oil (TTO) is a steam distillate of Melaleuca alternifolia that demonstrates broad-spectrum antibacterial activity. This study was designed to document how TTO challenge influences the Staphylococcus aureus transcriptome. Overall, bioinformatic analyses (S. aureus microarray meta-database) revealed that both ethanol and TTO induce related transcriptional alterations. TTO challenge led to the down-regulation of genes involved with energy-intensive transcription and translation, and altered the regulation of genes involved with heat shock (e.g. clpC, clpL, ctsR, dnaK, groES, groEL, grpE and hrcA) and cell wall metabolism (e.g. cwrA, isaA, sle1, vraSR and vraX). Inactivation of the heat shock gene dnaK or vraSR which encodes a two-component regulatory system that responds to peptidoglycan biosynthesis inhibition led to an increase in TTO susceptibility which demonstrates a protective role for these genes in the S. aureus TTO response. A gene (mmpL) encoding a putative resistance, nodulation and cell division efflux pump was also highly induced by TTO. The principal antimicrobial TTO terpene, terpinen-4-ol, altered ten genes in a transcriptional direction analogous to TTO. Collectively, this study provides additional insight into the response of a bacterial pathogen to the antimicrobial terpene mixture TTO.
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Affiliation(s)
- Jesus A Cuaron
- Microbiology Group, Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA
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24
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Sun F, Zhou L, Zhao BC, Deng X, Cho H, Yi C, Jian X, Song CX, Luan CH, Bae T, Li Z, He C. Targeting MgrA-mediated virulence regulation in Staphylococcus aureus. ACTA ACUST UNITED AC 2011; 18:1032-41. [PMID: 21867918 DOI: 10.1016/j.chembiol.2011.05.014] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 05/02/2011] [Accepted: 05/26/2011] [Indexed: 12/17/2022]
Abstract
Increasing antibiotic resistance in human pathogens necessitates the development of new approaches against infections. Targeting virulence regulation at the transcriptional level represents a promising strategy yet to be explored. A global transcriptional regulator, MgrA in Staphylococcus aureus, was identified previously as a key virulence determinant. We have performed a fluorescence anisotropy (FA)-based high-throughput screen that identified 5, 5-methylenedisalicylic acid (MDSA), which blocks the DNA binding of MgrA. MDSA represses the expression of α-toxin that is up-regulated by MgrA and activates the transcription of protein A, a gene down-regulated by MgrA. MDSA alters bacterial antibiotic susceptibilities via an MgrA-dependent pathway. A mouse model of infection indicated that MDSA could attenuate S. aureus virulence. This work is a rare demonstration of utilizing small molecules to block protein-DNA interaction, thus tuning important biological regulation at the transcriptional level.
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Affiliation(s)
- Fei Sun
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA
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25
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Riordan JT, Dupre JM, Cantore-Matyi SA, Kumar-Singh A, Song Y, Zaman S, Horan S, Helal NS, Nagarajan V, Elasri MO, Wilkinson BJ, Gustafson JE. Alterations in the transcriptome and antibiotic susceptibility of Staphylococcus aureus grown in the presence of diclofenac. Ann Clin Microbiol Antimicrob 2011; 10:30. [PMID: 21774834 PMCID: PMC3158543 DOI: 10.1186/1476-0711-10-30] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 07/21/2011] [Indexed: 11/24/2022] Open
Abstract
Background Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) which has been shown to increase the susceptibility of various bacteria to antimicrobials and demonstrated to have broad antimicrobial activity. This study describes transcriptome alterations in S. aureus strain COL grown with diclofenac and characterizes the effects of this NSAID on antibiotic susceptibility in laboratory, clinical and diclofenac reduced-susceptibility (DcRS) S. aureus strains. Methods Transcriptional alterations in response to growth with diclofenac were measured using S. aureus gene expression microarrays and quantitative real-time PCR. Antimicrobial susceptibility was determined by agar diffusion MICs and gradient plate analysis. Ciprofloxacin accumulation was measured by fluorescence spectrophotometry. Results Growth of S. aureus strain COL with 80 μg/ml (0.2 × MIC) of diclofenac resulted in the significant alteration by ≥2-fold of 458 genes. These represented genes encoding proteins for transport and binding, protein and DNA synthesis, and the cell envelope. Notable alterations included the strong down-regulation of antimicrobial efflux pumps including mepRAB and a putative emrAB/qacA-family pump. Diclofenac up-regulated sigB (σB), encoding an alternative sigma factor which has been shown to be important for antimicrobial resistance. Staphylococcus aureus microarray metadatabase (SAMMD) analysis further revealed that 46% of genes differentially-expressed with diclofenac are also σB-regulated. Diclofenac altered S. aureus susceptibility to multiple antibiotics in a strain-dependent manner. Susceptibility increased for ciprofloxacin, ofloxacin and norfloxacin, decreased for oxacillin and vancomycin, and did not change for tetracycline or chloramphenicol. Mutation to DcRS did not affect susceptibility to the above antibiotics. Reduced ciprofloxacin MICs with diclofenac in strain BB255, were not associated with increased drug accumulation. Conclusions The results of this study suggest that diclofenac influences antibiotic susceptibility in S. aureus, in part, by altering the expression of regulatory and structural genes associated with cell wall biosynthesis/turnover and transport.
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Affiliation(s)
- James T Riordan
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA.
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26
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Salicylic acid enhances Staphylococcus aureus extracellular adhesin protein expression. Microbes Infect 2011; 13:1073-80. [PMID: 21714946 DOI: 10.1016/j.micinf.2011.06.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 06/08/2011] [Accepted: 06/09/2011] [Indexed: 11/24/2022]
Abstract
One of the virulence factors required by Staphylococcus aureus at the early stages of infection is Eap, a secreted adhesin that binds many host proteins and is upregulated by the two-component regulatory system saeRS. The S. aureus Newman strain harbors a mutation in saeS that is thought to be responsible for the high level of Eap expression in this strain. This study was designed to ascertain whether salicylic acid (SAL) affects the expression of Eap and the internalization of S. aureus into epithelial cells. The strain Newman treated with SAL exhibited increased levels of eap transcription and protein expression. Furthermore, SAL treatment increased the eap promoter activity. SAL treatment enhanced Eap expression in the Newman and in other S. aureus strains that do not carry the mutation in saeS. Internalization of S. aureus eap and sae mutants into the MAC-T epithelial cells was significantly decreased compared with the wild-type counterparts. In conclusion, we demonstrated that a low concentration of SAL increased S. aureus Eap expression possibly due to enhancement of sae. SAL may create the conditions for S. aureus persistence in the host, not only by decreasing the capsular polysaccharide expression as shown before, but also by enhancing Eap expression.
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27
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Giotis ES, Muthaiyan A, Natesan S, Wilkinson BJ, Blair IS, McDowell DA. Transcriptome analysis of alkali shock and alkali adaptation in Listeria monocytogenes 10403S. Foodborne Pathog Dis 2010; 7:1147-57. [PMID: 20677981 PMCID: PMC3132107 DOI: 10.1089/fpd.2009.0501] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Alkali stress is an important means of inactivating undesirable pathogens in a wide range of situations. Unfortunately, Listeria monocytogenes can launch an alkaline tolerance response, significantly increasing persistence of the pathogen in such environments. This study compared transcriptome patterns of alkali and non-alkali-stressed L. monocytogenes 10403S cells, to elucidate the mechanisms by which Listeria adapts and/or grows during short- or long-term alkali stress. Transcription profiles associated with alkali shock (AS) were obtained by DNA microarray analysis of midexponential cells suspended in pH 9 media for 15, 30, or 60 min. Transcription profiles associated with alkali adaptation (AA) were obtained similarly from cells grown to midexponential phase at pH 9. Comparison of AS and AA transcription profiles with control cell profiles identified a high number of differentially regulated open-reading frames in all tested conditions. Rapid (15 min) changes in expression included upregulation of genes encoding for multiple metabolic pathways (including those associated with Na+/H+ antiporters), ATP-binding cassette transporters of functional compatible solutes, motility, and virulence-associated genes as well as the σ(B) controlled stress resistance network. Slower (30 min and more) responses to AS and adaptation during growth in alkaline conditions (AA) involved a different pattern of changes in mRNA concentrations, and genes involved in proton export.
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Affiliation(s)
- Efstathios S. Giotis
- Food Microbiology Research Group, School of Health Sciences, University of Ulster, Northern Ireland, United Kingdom
- Microbiology Group, Department of Biological Sciences, Illinois State University, Normal, Illinois
| | - Arunachalam Muthaiyan
- Microbiology Group, Department of Biological Sciences, Illinois State University, Normal, Illinois
| | - Senthil Natesan
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Colchester, Vermont
| | - Brian J. Wilkinson
- Microbiology Group, Department of Biological Sciences, Illinois State University, Normal, Illinois
| | - Ian S. Blair
- Food Microbiology Research Group, School of Health Sciences, University of Ulster, Northern Ireland, United Kingdom
| | - David A. McDowell
- Food Microbiology Research Group, School of Health Sciences, University of Ulster, Northern Ireland, United Kingdom
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Hartog E, Menashe O, Kler E, Yaron S. Salicylate reduces the antimicrobial activity of ciprofloxacin against extracellular Salmonella enterica serovar Typhimurium, but not against Salmonella in macrophages. J Antimicrob Chemother 2010; 65:888-96. [PMID: 20237076 DOI: 10.1093/jac/dkq077] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
OBJECTIVES Salicylate, a potent inducer of the MarA activator in Salmonella enterica, is the principal metabolite of aspirin, which is often consumed for medicinal and cosmetic uses. Our research was aimed at testing if salicylate activates the mar regulon in macrophage-associated Salmonella (intracellular bacteria), and investigating its effects on bacterial susceptibility to ciprofloxacin extracellularly and intracellularly. METHODS J774 macrophages were infected with S. enterica serovar Typhimurium (wild-type and marA null mutant), treated with ciprofloxacin with and without pre-exposure to salicylate, and the surviving bacteria were counted. Similar experiments were conducted with bacteria in broth (extracellular bacteria). Phe-Arg-beta-naphthylamide (PAbetaN) was added to investigate the role of efflux pumps in resistance. The transcriptional regulation of marRAB, acrAB and micF in extracellular and intracellular Salmonella Typhimurium with and without salicylate and ciprofloxacin was investigated using green fluorescent protein as a marker protein and quantitative real time PCR. RESULTS Pre-exposure of Salmonella to salicylate increased the resistance of extracellular but not intracellular bacteria to ciprofloxacin, although salicylate stimulated the expression of mar genes in intracellular and extracellular bacteria. Using marA mutants and the inhibitor PAbetaN, we showed that the improved resistance in extracellular bacteria is derived from the induction of acrAB by salicylate, which is mediated by MarA. CONCLUSIONS In intracellular bacteria, the expression of acrAB is already higher when compared with extracellular cells; therefore, salicylate does not result in significant acrAB induction intracellularly and subsequent resistance enhancement. Results show that conclusions raised from extracellular studies cannot be applied to intracellular bacteria, although the systems have similar functions.
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Affiliation(s)
- Efrat Hartog
- Faculty of Biotechnology and Food Engineering, Technion, Haifa 32000, Israel
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Salicylic acid diminishes Staphylococcus aureus capsular polysaccharide type 5 expression. Infect Immun 2009; 78:1339-44. [PMID: 20008532 DOI: 10.1128/iai.00245-09] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Capsular polysaccharides (CP) of serotypes 5 (CP5) and 8 (CP8) are major Staphylococcus aureus virulence factors. Previous studies have shown that salicylic acid (SAL), the main aspirin metabolite, affects the expression of certain bacterial virulence factors. In the present study, we found that S. aureus strain Reynolds (CP5) cultured with SAL was internalized by MAC-T cells in larger numbers than strain Reynolds organisms not exposed to SAL. Furthermore, the internalization of the isogenic nonencapsulated Reynolds strain into MAC-T cells was not significantly affected by preexposure to SAL. Pretreatment of S. aureus strain Newman with SAL also enhanced internalization into MAC-T cells compared with that of untreated control strains. Using strain Newman organisms, we evaluated the activity of the major cap5 promoter, which was significantly decreased upon preexposure to SAL. Diminished transcription of mgrA and upregulation of the saeRS transcript, both global regulators of CP expression, were found in S. aureus cultured in the presence of SAL, as ascertained by real-time PCR analysis. In addition, CP5 production by S. aureus Newman was also decreased by treatment with SAL. Collectively, our data demonstrate that exposure of encapsulated S. aureus strains to low concentrations of SAL reduced CP production, thus unmasking surface adhesins and leading to an increased capacity of staphylococci to invade epithelial cells. The high capacity of internalization of the encapsulated S. aureus strains induced by SAL pretreatment may contribute to the persistence of bacteria in certain hosts.
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Lanfranconi MP, Christie-Oleza JA, MartÃn-Cardona CÃ, Suárez-Suárez LY, Lalucat J, Nogales B, Bosch R. Physiological role of NahW, the additional salicylate hydroxylase found inPseudomonas stutzeriAN10. FEMS Microbiol Lett 2009; 300:265-72. [DOI: 10.1111/j.1574-6968.2009.01787.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Lamichhane-Khadka R, Riordan JT, Delgado A, Muthaiyan A, Reynolds TD, Wilkinson BJ, Gustafson JE. Genetic changes that correlate with the pine-oil disinfectant-reduced susceptibility mechanism of Staphylococcus aureus. J Appl Microbiol 2009; 105:1973-81. [PMID: 19120644 DOI: 10.1111/j.1365-2672.2008.03956.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS To identify factors associated with the Staphylococcus aureus pine-oil disinfectant-reduced-susceptibility (PD(RS)) mechanism and to describe one possible PD(RS) model. METHODS AND RESULTS Comparative genomic sequencing (CGS) and microarray analysis were utilized to detect mutations and transcriptome alterations that occur in a S. aureus PD(RS) mutant. Mutant analysis, antimicrobial gradient plates, growth studies and 3-hydroxy-3-methylglutaryl coenzyme A synthase assays were then performed to confirm the biological consequences of the 'omics' alterations detected in a PD(RS) mutant. CGS uncovered three mutations in a PD(RS) mutant in a(n): alcohol dehydrogenase (adh), catabolite control protein A (ccpA) and an NADPH-flavin oxidoreductase (frp). These mutations lead to increased growth rates; increased transcription of an NAD-dependent D-lactate dehydrogenase gene (ddh); and increased flux through the mevalonate pathway. PD(RS) mutants demonstrated reduced susceptibility to bacitracin and farnesol, and one PD(RS) mutant displayed upregulation of bacA, a bacitracin-resistance gene. Collectively, this evidence demonstrates altered undecaprenol metabolism in PD(RS) mutants. CONCLUSIONS The PD(RS) mechanism proposed results from increased catabolic capabilities and increased flux through the mevalonate pathway as well as altered bactoprenol physiology. SIGNIFICANCE AND IMPACT OF THE STUDY A novel mechanism that bacteria utilize to overcome the killing effects of PD formulations is proposed that is unique from the PD(RS) mechanism of the enterobacteraciae.
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Affiliation(s)
- R Lamichhane-Khadka
- Department of Biology, New Mexico State University, Las Cruces, NM 88003-8001, USA
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Abstract
Drug efflux pumps play a key role in drug resistance and also serve other functions in bacteria. There has been a growing list of multidrug and drug-specific efflux pumps characterized from bacteria of human, animal, plant and environmental origins. These pumps are mostly encoded on the chromosome, although they can also be plasmid-encoded. A previous article in this journal provided a comprehensive review regarding efflux-mediated drug resistance in bacteria. In the past 5 years, significant progress has been achieved in further understanding of drug resistance-related efflux transporters and this review focuses on the latest studies in this field since 2003. This has been demonstrated in multiple aspects that include but are not limited to: further molecular and biochemical characterization of the known drug efflux pumps and identification of novel drug efflux pumps; structural elucidation of the transport mechanisms of drug transporters; regulatory mechanisms of drug efflux pumps; determining the role of the drug efflux pumps in other functions such as stress responses, virulence and cell communication; and development of efflux pump inhibitors. Overall, the multifaceted implications of drug efflux transporters warrant novel strategies to combat multidrug resistance in bacteria.
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Affiliation(s)
- Xian-Zhi Li
- Human Safety Division, Veterinary Drugs Directorate, Health Products and Food Branch, Health Canada, Ottawa, Ontario K1A OK9, Canada
| | - Hiroshi Nikaido
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3202, USA
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Kaufman J, Griffiths TA, Surette MG, Ness S, Rioux KP. Effects of mesalamine (5-aminosalicylic acid) on bacterial gene expression. Inflamm Bowel Dis 2009; 15:985-96. [PMID: 19202572 DOI: 10.1002/ibd.20876] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND 5-Aminosalicylic acid (5-ASA) is a well-established treatment for inflammatory bowel disease (IBD) and may reduce the risk of colon cancer in patients with chronic colitis, but the mechanisms underlying these effects have not been fully elucidated. Although 5-ASA delivery is targeted to the distal gut, little is known about its effects on the luminal bacteria that reside there. Intestinal bacteria are believed play a role in causing or perpetuating IBD, and bioremediation has been studied as a therapeutic strategy. In an effort to better understand the bacteriological effects of 5-ASA, we examined the role of this compound at the level of bacterial gene expression. METHODS 5-ASA was screened for its effects on a random promoter library representing the genome of Salmonella enterica serovar Typhimurium as a model enteric bacterium. Forty-five constructs representing 38 unique promoters were found to be responsive to 5-ASA, and included genes involved in bacterial invasion, cellular metabolism, and stress resistance. Several genes of unknown function were also identified. These effects occurred at 5-ASA concentrations that are relevant to those achieved in the distal intestinal tract in patients with IBD but did not inhibit bacterial growth. RESULTS Bacterial invasiveness was decreased by 5-ASA. Some of the identified genes had homologs among commensal Gram-negative enteric bacteria. CONCLUSIONS This study demonstrates that 5-ASA has potent effects on bacterial gene expression. These novel findings implicate intestinal bacteria as pharmacological targets of 5-ASA, perhaps contributing to the therapeutic action of this important class of IBD drugs.
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Affiliation(s)
- Jaime Kaufman
- Department of Medicine, Division of Gastroenterology, University of Calgary, Calgary, Alberta, Canada
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Lamichhane-Khadka R, Cantore SA, Riordan JT, Delgado A, Norman AEA, Dueñas S, Zaman S, Horan S, Wilkinson BJ, Gustafson JE. sarA inactivation reduces vancomycin-intermediate and ciprofloxacin resistance expression by Staphylococcus aureus. Int J Antimicrob Agents 2009; 34:136-41. [PMID: 19324528 DOI: 10.1016/j.ijantimicag.2009.01.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 11/25/2008] [Accepted: 01/16/2009] [Indexed: 11/18/2022]
Abstract
It is known that multiple genome-wide transcriptional changes often accompany the development of antimicrobial resistance and occur in response to challenge with antimicrobial agents. We now show that inactivation of the staphylococcal accessory gene regulator sarA, which controls at least tens of genes in Staphylococcus aureus, leads to dramatic reductions in vancomycin and ciprofloxacin resistance in vancomycin-intermediate and ciprofloxacin-resistant strains of S. aureus. This is particularly evident when judged by antimicrobial-gradient plate analysis or population analysis profiles. Whilst the intact sarA cistron is required for full vancomycin resistance expression by vancomycin-intermediate S. aureus (VISA), sarA expression as determined by quantitative real-time polymerase chain reaction was found to be VISA strain-dependent. Reductions in vancomycin resistance expression levels following sarA inactivation do not necessarily include an alteration in autolysis. Expression of sarR, the negative regulator of sarA, was downregulated in two VISA mutants, and transcription of the alternative sigma factor sigB was downregulated in one VISA strain. This study contributes to a growing body of evidence demonstrating the importance of loci previously identified to control virulence in the regulation of clinically relevant antibiotic resistance mechanisms.
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Chen PR, Nishida S, Poor CB, Cheng A, Bae T, Kuechenmeister L, Dunman PM, Missiakas D, He C. A new oxidative sensing and regulation pathway mediated by the MgrA homologue SarZ in Staphylococcus aureus. Mol Microbiol 2008; 71:198-211. [PMID: 19007410 DOI: 10.1111/j.1365-2958.2008.06518.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Oxidative stress serves as an important host/environmental signal that triggers a wide range of responses from the human pathogen Staphylococcus aureus. Among these, a thiol-based oxidation sensing pathway through a global regulator MgrA controls the virulence and antibiotic resistance of the bacterium. Herein, we report a new thiol-based oxidation sensing and regulation system that is mediated through a parallel global regulator SarZ. SarZ is a functional homologue of MgrA and is shown to affect the expression of approximately 87 genes in S. aureus. It uses a key Cys residue, Cys-13, to sense oxidative stress and to co-ordinate the expression of genes involved in metabolic switching, antibiotic resistance, peroxide stress defence, virulence, and cell wall properties. The discovery of this SarZ-mediated regulation, mostly independent from the MgrA-based regulation, fills a missing gap of oxidation sensing and response in S. aureus.
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Affiliation(s)
- Peng R Chen
- Department of Chemistry, 929 East 57th Street, The University of Chicago, Chicago, IL, USA
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Delgado A, Zaman S, Muthaiyan A, Nagarajan V, Elasri MO, Wilkinson BJ, Gustafson JE. The fusidic acid stimulon of Staphylococcus aureus. J Antimicrob Chemother 2008; 62:1207-14. [PMID: 18786940 DOI: 10.1093/jac/dkn363] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVES Fusidic acid interferes with the release of elongation factor G (EF-G) after the translocation step of protein synthesis. The objective of this study was to characterize the fusidic acid stimulon of a fusidic acid-susceptible strain of Staphylococcus aureus (SH1000). METHODS S. aureus microarrays and real-time PCR determined transcriptome alterations occurring in SH1000 grown with fusidic acid. The Staphylococcus aureus microarray meta-database (SAMMD) compared and contrasted the SH1000 fusidic stimulon with 89 other S. aureus transcriptional datasets. Fusidic acid gradient analyses with mutant-parent strain pairs were used to identify genes required for intrinsic fusidic acid susceptibility identified during transcriptional analysis. RESULTS Many genes altered by fusidic acid challenge are associated with protein synthesis. SAMMD analysis determined that the fusidic acid stimulon has the greatest overlap with the S. aureus cold shock and stringent responses. Six out of nine peptidoglycan hydrolase genes making up the two component YycFG regulon were also up-regulated by fusidic acid, as were a carboxylesterase gene (est) and two putative drug efflux pump genes (emr-qac1 and macA). Genes down-regulated by fusidic acid induction encoded a putative secreted acid phosphatase and a number of protease genes. Roles for the agr operon, the peptidoglycan hydrolase gene isaA and two proteases (htrA1 and htrA2) in the expression of fusidic acid susceptibility were revealed. CONCLUSIONS The SH1000 fusidic acid stimulon includes genes involved with two stress responses, YycFG-regulated cell wall metabolism, drug efflux, and protein synthesis and turnover.
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Affiliation(s)
- Alejandro Delgado
- Microbiology Group, Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA
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Yuan ZC, Haudecoeur E, Faure D, Kerr KF, Nester EW. Comparative transcriptome analysis of Agrobacterium tumefaciens in response to plant signal salicylic acid, indole-3-acetic acid and gamma-amino butyric acid reveals signalling cross-talk and Agrobacterium--plant co-evolution. Cell Microbiol 2008; 10:2339-54. [PMID: 18671824 DOI: 10.1111/j.1462-5822.2008.01215.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Agrobacterium has evolved sophisticated strategies to perceive and transduce plant-derived cues. Recent studies have found that numerous plant signals, including salicylic acid (SA), indole-3-acetic acid (IAA) and gamma-amino butyric acid (GABA), profoundly affect Agrobacterium-plant interactions. Here we determine and compare the transcriptome profiles of Agrobacterium in response to these three plant signals. Collectively, the transcription of 103, 115 and 95 genes was significantly altered by SA, IAA and GABA respectively. Both distinct cellular responses and overlapping signalling pathways were elicited by these three plant signals. Interestingly, these three plant compounds function additively to shut off the Agrobacterium virulence programme and activate the quorum-quenching machinery. Moreover, the repression of the virulence programme by SA and IAA and the inactivation of quorum-sensing signals by SA and GABA are regulated through independent pathways. Our data indicate that these plant signals, while cross-talk in plant signalling networks, also act as cross-kingdom signals and play redundant roles in tailoring Agrobacterium regulatory pathways, resulting in intensive signalling cross-talk in Agrobacterium. Our results support the notion that Agrobacterium has evolved the ability to hijack plant signals for its own benefit. The complex signalling interplay between Agrobacterium and its plant hosts reflects an exquisite co-evolutionary balance.
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Affiliation(s)
- Ze-Chun Yuan
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
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Giotis ES, Muthaiyan A, Blair IS, Wilkinson BJ, McDowell DA. Genomic and proteomic analysis of the Alkali-Tolerance Response (AlTR) in Listeria monocytogenes 10403S. BMC Microbiol 2008; 8:102. [PMID: 18577215 PMCID: PMC2443805 DOI: 10.1186/1471-2180-8-102] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Accepted: 06/24/2008] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Information regarding the Alkali-Tolerance Response (AlTR) in Listeria monocytogenes is very limited. Treatment of alkali-adapted cells with the protein synthesis inhibitor chloramphenicol has revealed that the AlTR is at least partially protein-dependent. In order to gain a more comprehensive perspective on the physiology and regulation of the AlTR, we compared differential gene expression and protein content of cells adapted at pH 9.5 and un-adapted cells (pH 7.0) using complementary DNA (cDNA) microarray and two-dimensional (2D) gel electrophoresis, (combined with mass spectrometry) respectively. RESULTS In this study, L. monocytogenes was shown to exhibit a significant AlTR following a 1-h exposure to mild alkali (pH 9.5), which is capable of protecting cells from subsequent lethal alkali stress (pH 12.0). Adaptive intracellular gene expression involved genes that are associated with virulence, the general stress response, cell division, and changes in cell wall structure and included many genes with unknown functions. The observed variability between results of cDNA arrays and 2D gel electrophoresis may be accounted for by posttranslational modifications. Interestingly, several alkali induced genes/proteins can provide a cross protective overlap to other types of stresses. CONCLUSION Alkali pH provides therefore L. monocytogenes with nonspecific multiple-stress resistance that may be vital for survival in the human gastrointestinal tract as well as within food processing systems where alkali conditions prevail. This study showed strong evidence that the AlTR in L. monocytogenes functions as to minimize excess alkalisation and energy expenditures while mobilizing available carbon sources.
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Affiliation(s)
- Efstathios S Giotis
- Food Microbiology Research Group, University of Ulster, Northern Ireland, UK
| | | | - Ian S Blair
- Food Microbiology Research Group, University of Ulster, Northern Ireland, UK
| | | | - David A McDowell
- Food Microbiology Research Group, University of Ulster, Northern Ireland, UK
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