101
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Tan S, Ludwig KC, Müller A, Schneider T, Nodwell JR. The Lasso Peptide Siamycin-I Targets Lipid II at the Gram-Positive Cell Surface. ACS Chem Biol 2019; 14:966-974. [PMID: 31026131 DOI: 10.1021/acschembio.9b00157] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ribosomally synthesized post-translationally modified peptides (RiPPs) are a diverse class of biologically active molecules produced by many environmental bacteria. While thousands of these compounds have been identified, mostly through genome mining, a relatively small number has been investigated at the molecular level. One less understood class of RiPPs is the lasso peptides. These are 20-25 amino acid residue compounds bearing an N-terminal macrocyclic ring and a C-terminal tail that is threaded through the ring. We have carried out a detailed investigation on the mechanism of action of the siamycin-I lasso peptide. We demonstrate that siamycin-I interacts with lipid II, the central building block of the major cell wall component peptidoglycan, which is readily accessible on the outside of the cell. This interaction compromises cell wall biosynthesis in a manner that activates the liaI stress response. Additionally, resistance to siamycin-I can be brought about by mutations in the essential WalKR two-component system that causes thickening of the cell wall. Siamycin-I is the first lasso peptide that has been shown to inhibit cell wall biosynthesis.
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Affiliation(s)
- Stephanie Tan
- Department of Biochemistry, MaRS Discovery District, University of Toronto, 661 University Avenue, Toronto, Ontario, Canada M5G 1M1
| | - Kevin C. Ludwig
- Institute for Pharmaceutical Microbiology, University of Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany
| | - Anna Müller
- Institute for Pharmaceutical Microbiology, University of Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany
- German Centre for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany
| | - Tanja Schneider
- Institute for Pharmaceutical Microbiology, University of Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany
- German Centre for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany
| | - Justin R. Nodwell
- Department of Biochemistry, MaRS Discovery District, University of Toronto, 661 University Avenue, Toronto, Ontario, Canada M5G 1M1
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102
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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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103
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Intestinal Bile Acids Induce a Morphotype Switch in Vancomycin-Resistant Enterococcus that Facilitates Intestinal Colonization. Cell Host Microbe 2019; 25:695-705.e5. [PMID: 31031170 DOI: 10.1016/j.chom.2019.03.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 01/25/2019] [Accepted: 03/18/2019] [Indexed: 12/22/2022]
Abstract
Vancomycin-resistant Enterococcus (VRE) are highly antibiotic-resistant and readily transmissible pathogens that cause severe infections in hospitalized patients. We discovered that lithocholic acid (LCA), a secondary bile acid prevalent in the cecum and colon of mice and humans, impairs separation of growing VRE diplococci, causing the formation of long chains and increased biofilm formation. Divalent cations reversed this LCA-induced switch to chaining and biofilm formation. Experimental evolution in the presence of LCA yielded mutations in the essential two-component kinase yycG/walK and three-component response regulator liaR that locked VRE in diplococcal mode, impaired biofilm formation, and increased susceptibility to the antibiotic daptomycin. These mutant VRE strains were deficient in host colonization because of their inability to compete with intestinal microbiota. This morphotype switch presents a potential non-bactericidal therapeutic target that may help clear VRE from the intestines of dominated patients, as occurs frequently during hematopoietic stem cell transplantation.
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104
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Impact of an Antimicrobial Stewardship Intervention on Within- and Between-Patient Daptomycin Resistance Evolution in Vancomycin-Resistant Enterococcus faecium. Antimicrob Agents Chemother 2019; 63:AAC.01800-18. [PMID: 30718245 DOI: 10.1128/aac.01800-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 01/17/2019] [Indexed: 12/14/2022] Open
Abstract
Vancomycin-resistant Enterococcus (VRE) is a leading cause of hospital-acquired infection, with limited treatment options. Resistance to one of the few remaining drugs, daptomycin, is a growing clinical problem and has previously been described in this hospital. In response to increasing resistance, an antimicrobial stewardship intervention was implemented to reduce hospital-wide use of daptomycin. To assess the impact of the intervention, daptomycin prescribing patterns and clinically reported culture results from vancomycin-resistant Enterococcus faecium (VREfm) bloodstream infections (BSIs) from 2011 through 2017 were retrospectively extracted and the impact of the intervention was estimated using interrupted time series analysis (ITS). We corrected for a change in MIC determination methodology by retesting 262 isolates using Etest and broth microdilution. Hospital-wide and within-patient resistance patterns of corrected daptomycin MICs are reported. Our data show that daptomycin prescriptions decreased from an average of 287 days of therapy/month preintervention to 151 days of therapy/month postintervention. Concurrently, the proportion of patients experiencing an increase in daptomycin MIC during an infection declined from 14.6% (7/48 patients) in 2014 to 1.9% (1/54 patients) in 2017. Hospital-wide resistance to daptomycin also decreased in the postintervention period, but this was not maintained. This study shows that an antimicrobial stewardship-guided intervention reduced daptomycin use and improved individual level outcomes but had only transient impact on the hospital-level trend.
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105
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France MT, Cornea A, Kehlet‐Delgado H, Forney LJ. Spatial structure facilitates the accumulation and persistence of antibiotic-resistant mutants in biofilms. Evol Appl 2019; 12:498-507. [PMID: 30828370 PMCID: PMC6383844 DOI: 10.1111/eva.12728] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 09/16/2018] [Accepted: 10/02/2018] [Indexed: 01/13/2023] Open
Abstract
The emergence and spread of antibiotic resistance in bacterial pathogens are a global crisis. Because many bacterial infections are caused by pathogens that reside in biofilms, we sought to investigate how biofilms influence the evolution of antibiotic resistance. We hypothesize that the inherent spatial structure of biofilms facilitates the accumulation and persistence of spontaneously evolved antibiotic-resistant mutants. To test this, we tracked the frequency of mutants resistant to kanamycin and rifampicin in biofilm populations of Escherichia coli before, during, and after an antibiotic treatment regimen. Our results show that biofilms accumulate resistant mutants even in the absence of antibiotics. This resistance was found to be heritable and thus unlike the phenotypic plasticity of so-called "persister cells" that have been shown to occur in biofilms. Upon exposure to an antibiotic, resistant mutants swept to high frequency. Following the conclusion of treatment, these resistant mutants remained at unexpectedly high frequencies in the biofilms for over 45 days. In contrast, when samples from kanamycin-treated biofilms were used to found well-mixed liquid cultures and propagated by serial transfer, the frequency of resistant cells dramatically decreased as they were outcompeted by sensitive clones. These observations suggest that the emergence of antibiotic resistance through spontaneous mutations in spatially structured biofilms may significantly contribute to the emergence and persistence of mutants that are resistant to antibiotics used to treat bacterial infections.
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Affiliation(s)
- Michael T. France
- Institute for Bioinformatics and Evolutionary StudiesUniversity of IdahoMoscowIdaho
- Present address:
Institute for Genome Sciences, School of MedicineUniversity of MarylandBaltimoreMaryland
| | - Ana Cornea
- Department of Biological SciencesUniversity of IdahoMoscowIdaho
- Present address:
School of MedicineUniversity of WashingtonSeattleWashington
| | - Hanna Kehlet‐Delgado
- Department of Biological SciencesUniversity of IdahoMoscowIdaho
- Present address:
Department of MicrobiologyOregon State UniversityCorvallisOregon
| | - Larry J. Forney
- Institute for Bioinformatics and Evolutionary StudiesUniversity of IdahoMoscowIdaho
- Department of Biological SciencesUniversity of IdahoMoscowIdaho
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106
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Lasek-Nesselquist E, Lu J, Schneider R, Ma Z, Russo V, Mishra S, Pai MP, Pata JD, McDonough KA, Malik M. Insights Into the Evolution of Staphylococcus aureus Daptomycin Resistance From an in vitro Bioreactor Model. Front Microbiol 2019; 10:345. [PMID: 30891010 PMCID: PMC6413709 DOI: 10.3389/fmicb.2019.00345] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 02/08/2019] [Indexed: 02/02/2023] Open
Abstract
The extensive use of daptomycin for treating complex methicillin-resistant Staphylococcus aureus infections has led to the emergence of daptomycin-resistant strains. Although genomic studies have identified mutations associated with daptomycin resistance, they have not necessarily provided insight into the evolution and hierarchy of genetic changes that confer resistance, particularly as antibiotic concentrations are increased. Additionally, plate-dependent in vitro analyses that passage bacteria in the presence of antibiotics can induce selective pressures unrelated to antibiotic exposure. We established a continuous culture bioreactor model that exposes S. aureus strain N315 to increasing concentrations of daptomycin without the confounding effects of nutritional depletion to further understand the evolution of drug resistance and validate the bioreactor as a method that produces clinically relevant results. Samples were collected every 24 h for a period of 14 days and minimum inhibitory concentrations were determined to monitor the acquisition of daptomycin resistance. The collected samples were then subjected to whole genome sequencing. The development of daptomycin resistance in N315 was associated with previously identified mutations in genes coding for proteins that alter cell membrane charge and composition. Although genes involved in metabolic functions were also targets of mutation, the common route to resistance relied on a combination of mutations at a few key loci. Tracking the frequency of each mutation throughout the experiment revealed that mutations need not arise progressively in response to increasing antibiotic concentrations and that most mutations were present at low levels within populations earlier than would be recorded based on single-nucleotide polymorphism (SNP) filtering criteria. In contrast, a serial-passaged population showed only one mutation in a gene associated with resistance and provided limited detail on the changes that occur upon exposure to higher drug dosages. To conclude, this study demonstrates the successful in vitro modeling of antibiotic resistance in a bioreactor and highlights the evolutionary paths associated with the acquisition of daptomycin non-susceptibility.
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Affiliation(s)
| | - Jackson Lu
- Albany College of Pharmacy and Health Sciences, Albany, NY, United States
| | - Ryan Schneider
- Department of Biomedical Sciences, University at Albany, School of Public Health, Albany, NY, United States
| | - Zhuo Ma
- Albany College of Pharmacy and Health Sciences, Albany, NY, United States
| | - Vincenzo Russo
- Albany College of Pharmacy and Health Sciences, Albany, NY, United States
| | - Smruti Mishra
- Albany College of Pharmacy and Health Sciences, Albany, NY, United States
| | - Manjunath P Pai
- Department of Clinical Pharmacy, University of Michigan, Ann Arbor, MI, United States
| | - Janice D Pata
- Wadsworth Center, New York State Department of Health, Albany, NY, United States.,Department of Biomedical Sciences, University at Albany, School of Public Health, Albany, NY, United States
| | - Kathleen A McDonough
- Wadsworth Center, New York State Department of Health, Albany, NY, United States.,Department of Biomedical Sciences, University at Albany, School of Public Health, Albany, NY, United States
| | - Meenakshi Malik
- Albany College of Pharmacy and Health Sciences, Albany, NY, United States
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107
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Evolution of Daptomycin Resistance in Coagulase-Negative Staphylococci Involves Mutations of the Essential Two-Component Regulator WalKR. Antimicrob Agents Chemother 2019; 63:AAC.01926-18. [PMID: 30617095 DOI: 10.1128/aac.01926-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 01/02/2019] [Indexed: 01/19/2023] Open
Abstract
Coagulase-negative staphylococci (CoNS) represent one of the major causes of health care- and medical device-associated infections. Emerging antimicrobial resistance has complicated the treatment of systemic infections caused by CoNS. Here, we describe the prevalence of antimicrobial resistance in clinical CoNS strains from a tertiary care hospital over a 4-year period, and we observed a significant increase in resistance to daptomycin. Notably, Staphylococcus capitis accounted for the majority of these daptomycin-resistant (DAP-R) CoNS. To further investigate the mechanisms of daptomycin resistance in CoNS, daptomycin-susceptible clinical strains of S. capitis and Staphylococcus epidermidis underwent in vitro daptomycin exposure to generate DAP-R CoNS mutants. Unlike that seen with Staphylococcus aureus, alteration of cell surface charge was not observed in the DAP-R CoNS strains, but biofilm formation was compromised. Whole-genome sequencing analysis of the DAP-R CoNS strains identified single nucleotide polymorphisms (SNPs) in walKR, the essential two-component regulatory system controlling cell wall biogenesis. PCR and sequencing of walK and walR from 17 DAP-R CoNS clinical isolates identified seven nonsynonymous mutations. The results were confirmed by the recreation of the walK SNP in S. epidermidis, which resulted in reduced susceptibility to daptomycin and vancomycin. This study highlights the significance of CoNS in evolving daptomycin resistance and showed that walKR is shared among the staphylococcal species and is involved in antibiotic resistance development. Notably, we did not observe mutations in genes responsible for phospholipid biosynthesis or an altered cell surface charge, suggesting that reduced daptomycin susceptibility in CoNS may emerge in a fashion distinct from that in S. aureus.
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108
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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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109
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Peng H, Rao Y, Yuan W, Zheng Y, Shang W, Hu Z, Yang Y, Tan L, Xiong K, Li S, Zhu J, Hu X, Hu Q, Rao X. Reconstruction of the Vancomycin-Susceptible Staphylococcus aureus Phenotype From a Vancomycin-Intermediate S. aureus XN108. Front Microbiol 2018; 9:2955. [PMID: 30546356 PMCID: PMC6279853 DOI: 10.3389/fmicb.2018.02955] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 11/16/2018] [Indexed: 11/17/2022] Open
Abstract
The emergence of vancomycin-intermediate Staphylococcus aureus (VISA) has raised healthcare concerns worldwide. VISA is often associated with multiple genetic changes. However, the relative contributions of these changes to VISA phenotypes are incompletely defined. We have characterized VISA XN108 with vancomycin MIC of 12 μg/ml. Genome comparison revealed that WalK(S221P), GraS(T136I), and RpoB(H481N) mutations possibly contributed to the VISA phenotype of XN108. In this study, the above mutations were stepwise cured, and the phenotypes between XN108 and its derivates were compared. We constructed four isogenic mutant strains, XN108-WalK(P221S) (termed as K65), XN108-GraS(I136T) (termed as S65), XN108-RpoB(N481H) (termed as B65), and XN108-WalK(P221S)/GraS(I136T) (termed as KS65), using the allelic replacement experiments with the native alleles derived from a vancomycin-susceptible S. aureus isolate DP65. Antimicrobial susceptibility test revealed K65 and S65 exhibited decreased vancomycin resistance, whereas B65 revealed negligibly differed when compared with the wild-type XN108. Sequentially introducing WalK(P221S) and GraS(I136T) completely converted XN108 into a VSSA phenotype. Transmission electronic microscopy and autolysis determination demonstrated that cell wall thickening and decreasing autolysis were associated with the change of vancomycin resistance levels. Compared with XN108, K65 exhibited 577 differentially expressed genes (DEGs), whereas KS65 presented 555 DEGs. Of those DEGs, 390 were common in K65 and KS65, including those upregulated genes responsible for citrate cycle and bacterial autolysis, and the downregulated genes involved in peptidoglycan biosynthesis and teichoic acid modification. In conclusion, a VSSA phenotype could be completely reconstituted from a VISA strain XN108. WalK(S221P) and GraS(T136I) mutations may work synergistically in conferring vancomycin resistance in XN108.
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Affiliation(s)
- Huagang Peng
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yifan Rao
- Institute of Modern Biopharmaceuticals, School of Life Sciences, Southwest University, Chongqing, China
| | - Wenchang Yuan
- Department of Clinical Laboratory, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Ying Zheng
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, China
| | - Weilong Shang
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, China
| | - Zhen Hu
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yi Yang
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, China
| | - Li Tan
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, China
| | - Kun Xiong
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, China
| | - Shu Li
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, China
| | - Junmin Zhu
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, China
| | - Xiaomei Hu
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, China
| | - Qiwen Hu
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, China
| | - Xiancai Rao
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University (Third Military Medical University), Chongqing, China
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110
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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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111
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Fyhrquist P, Virjamo V, Hiltunen E, Julkunen-Tiitto R. Epidihydropinidine, the main piperidine alkaloid compound of Norway spruce (Picea abies) shows antibacterial and anti-Candida activity. Fitoterapia 2018. [DOI: 10.1016/j.fitote.2018.12.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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112
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Coates-Brown R, Moran JC, Pongchaikul P, Darby AC, Horsburgh MJ. Comparative Genomics of Staphylococcus Reveals Determinants of Speciation and Diversification of Antimicrobial Defense. Front Microbiol 2018; 9:2753. [PMID: 30510546 PMCID: PMC6252332 DOI: 10.3389/fmicb.2018.02753] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/29/2018] [Indexed: 11/18/2022] Open
Abstract
The bacterial genus Staphylococcus comprises diverse species with most being described as colonizers of human and animal skin. A relational analysis of features that discriminate its species and contribute to niche adaptation and survival remains to be fully described. In this study, an interspecies, whole-genome comparative analysis of 21 Staphylococcus species was performed based on their orthologues. Three well-defined multi-species groups were identified: group A (including aureus/epidermidis); group B (including saprophyticus/xylosus) and group C (including pseudintermedius/delphini). The machine learning algorithm Random Forest was applied to prioritize orthologs that drive formation of the Staphylococcus species groups A-C. Orthologues driving staphylococcal intrageneric diversity comprised regulatory, metabolic and antimicrobial resistance proteins. Notably, the BraSR (NsaRS) two-component system (TCS) and its associated BraDE transporters that regulate antimicrobial resistance showed limited distribution in the genus and their presence was most closely associated with a subset of Staphylococcus species dominated by those that colonize human skin. Divergence of BraSR and GraSR antimicrobial peptide survival TCS and their associated transporters was observed across the staphylococci, likely reflecting niche specific evolution of these TCS/transporters and their specificities for AMPs. Experimental evolution, with selection for resistance to the lantibiotic nisin, revealed multiple routes to resistance and differences in the selection outcomes of the BraSR-positive species S. hominis and S. aureus. Selection supported a role for GraSR in nisin survival responses of the BraSR-negative species S. saprophyticus. Our study reveals diversification of antimicrobial-sensing TCS across the staphylococci and hints at differential relationships between GraSR and BraSR in those species positive for both TCS.
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Affiliation(s)
| | | | | | | | - Malcolm J. Horsburgh
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
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113
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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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114
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Giulieri SG, Baines SL, Guerillot R, Seemann T, Gonçalves da Silva A, Schultz M, Massey RC, Holmes NE, Stinear TP, Howden BP. Genomic exploration of sequential clinical isolates reveals a distinctive molecular signature of persistent Staphylococcus aureus bacteraemia. Genome Med 2018; 10:65. [PMID: 30103826 PMCID: PMC6090636 DOI: 10.1186/s13073-018-0574-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 07/27/2018] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Large-scale genomic studies of within-host diversity in Staphylococcus aureus bacteraemia (SAB) are needed to understanding bacterial adaptation underlying persistence and thus refining the role of genomics in management of SAB. However, available comparative genomic studies of sequential SAB isolates have tended to focus on selected cases of unusually prolonged bacteraemia, where secondary antimicrobial resistance has developed. METHODS To understand bacterial genetic diversity during SAB more broadly, we applied whole genome sequencing to a large collection of sequential isolates obtained from patients with persistent or relapsing bacteraemia. After excluding genetically unrelated isolates, we performed an in-depth genomic analysis of point mutations and chromosome structural variants arising within individual SAB episodes. RESULTS We show that, while adaptation pathways are heterogenous and episode-specific, isolates from persistent bacteraemia have a distinctive molecular signature, characterised by a low mutation frequency and high proportion of non-silent mutations. Analysis of structural genomic variants revealed that these often overlooked genetic events are commonly acquired during SAB. We discovered that IS256 insertion may represent the most effective driver of within-host microevolution in selected lineages, with up to three new insertion events per isolate even in the absence of other mutations. Genetic mechanisms resulting in significant phenotypic changes, such as increases in vancomycin resistance, development of small colony phenotypes, and decreases in cytotoxicity, included mutations in key genes (rpoB, stp, agrA) and an IS256 insertion upstream of the walKR operon. CONCLUSIONS This study provides for the first time a large-scale analysis of within-host genomic changes during invasive S. aureus infection and describes specific patterns of adaptation that will be informative for both understanding S. aureus pathoadaptation and utilising genomics for management of complicated S. aureus 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 & Immunity, Melbourne, Australia.,Infectious Disease Department, Austin Health, Melbourne, Australia.,Infectious Diseases Service, Department of Medicine, Lausanne University Hospital, Lausanne, Switzerland
| | - Sarah L Baines
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Australia
| | - Romain Guerillot
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Australia
| | - Torsten Seemann
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at The Doherty Institute of Infection and Immunity, Melbourne, Australia.,Melbourne Bioinformatics, The University of Melbourne, Melbourne, Australia
| | - Anders Gonçalves da Silva
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at The Doherty Institute of Infection and Immunity, Melbourne, Australia
| | - Mark Schultz
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at The Doherty Institute of Infection and Immunity, Melbourne, Australia
| | - Ruth C Massey
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Natasha E Holmes
- Infectious Disease Department, Austin Health, Melbourne, Australia
| | - Timothy P Stinear
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Australia
| | - Benjamin P Howden
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Australia. .,Infectious Disease Department, Austin Health, Melbourne, Australia. .,Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at The Doherty Institute of Infection and Immunity, Melbourne, Australia.
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115
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Ma Z, Lasek-Nesselquist E, Lu J, Schneider R, Shah R, Oliva G, Pata J, McDonough K, Pai MP, Rose WE, Sakoulas G, Malik M. Characterization of genetic changes associated with daptomycin nonsusceptibility in Staphylococcus aureus. PLoS One 2018; 13:e0198366. [PMID: 29879195 PMCID: PMC5991675 DOI: 10.1371/journal.pone.0198366] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 05/17/2018] [Indexed: 11/25/2022] Open
Abstract
The extensive use of daptomycin (DAP) for treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections in the last decade has led to the emergence of DAP non-susceptible (DNS) Staphylococcus aureus strains. A better understanding of the molecular changes underlying DAP-non-susceptibility is required for early diagnosis and intervention with alternate combination therapies. The phenotypic changes associated with DNS strains have been well established. However, the genotypic changes—especially the kinetics of expression of the genes responsible for DAP-non-susceptibility are not well understood. In this study, we used three clinically derived isogenic pairs of DAP-susceptible (DAP-S) and DNS S. aureus strains to study gene expression profiles with the objective of identifying the potential genotypic changes associated with DAP-nonsusceptibility. We determined the expression profiles of genes involved in cell membrane (CM) charge, autolysis, cell wall (CW) synthesis, and penicillin binding proteins in DAP-S and DNS isogenic pairs. Our results demonstrate characteristic expression profiles for mprF, dltABCD, vraS, femB, and pbp2a genes, which are common to all the DNS S. aureus strains tested. Whole genome sequencing of DAP-S and DNS clinical isolates of S. aureus showed non-synonymous mutations in all DNS strains in genes involved in CM charge, CM composition, CW thickness and CW composition. To conclude, this study unravels some of the complex molecular changes involved in the development of DAP-nonsusceptibility by demonstrating distinct differences in gene expression profiles and mutations in the DNS S. aureus strains. This knowledge will aid in rapid identification of DNS S. aureus in clinical settings.
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Affiliation(s)
- Zhuo Ma
- Albany College of Pharmacy and Health Sciences, Albany, New York, United States of America
| | - Erica Lasek-Nesselquist
- Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - Jackson Lu
- Albany College of Pharmacy and Health Sciences, Albany, New York, United States of America
| | - Ryan Schneider
- Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - Riddhi Shah
- Albany College of Pharmacy and Health Sciences, Albany, New York, United States of America
| | - George Oliva
- Albany College of Pharmacy and Health Sciences, Albany, New York, United States of America
| | - Janice Pata
- Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - Kathleen McDonough
- Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - Manjunath P. Pai
- Albany College of Pharmacy and Health Sciences, Albany, New York, United States of America
| | - Warren E. Rose
- Universtiy of Wisconsin-Madison, School of Pharmacy, Madison, Wisconsin, United States of America
| | - George Sakoulas
- Center for Immunity, Infection & Inflammation, UCSD School of Medicine, La Jolla, California, United States of America
| | - Meenakshi Malik
- Albany College of Pharmacy and Health Sciences, Albany, New York, United States of America
- * E-mail:
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116
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Lee GC, Dallas SD, Wang Y, Olsen RJ, Lawson KA, Wilson J, Frei CR. Emerging multidrug resistance in community-associated Staphylococcus aureus involved in skin and soft tissue infections and nasal colonization. J Antimicrob Chemother 2018; 72:2461-2468. [PMID: 28859442 DOI: 10.1093/jac/dkx200] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 05/12/2017] [Indexed: 12/21/2022] Open
Abstract
Background Staphylococcus aureus is a major pathogen causing significant morbidity and mortality worldwide. The emergence of MDR S. aureus strains in the community setting has major implications in disease management. However, data regarding the occurrence and patterns of MDR community-associated S. aureus sub-clones is limited. Objectives To use whole-genome sequences to describe the diversity and distribution of resistance mechanisms among community-associated S. aureus isolates. Methods S. aureus isolates from skin and soft tissue infections (SSTIs) and nasal colonization were collected from patients within 10 primary care clinics from 2007 to 2015. The Illumina Miseq platform was used to determine the genome sequences for 144 S. aureus isolates. Phylogenetic and bioinformatics analyses were performed using in silico tools. The resistome was assembled and compared with the phenotypically derived antibiogram. Results Approximately one-third of S. aureus isolates in the South Texas primary care setting were MDR. A higher proportion of SSTI isolates were MDR in comparison with nasal colonization isolates. Individuals with MDR S. aureus SSTIs were more likely to be African American and obese. Furthermore, S. aureus populations are able to acquire and lose antimicrobial resistance genes. USA300 strains were differentiated by a stable chromosomal mutation in gyrA conferring quinolone resistance. The resistomes were highly predictive of antimicrobial resistance phenotypes. Conclusions These findings highlight the high prevalence and epidemiological factors associated with MDR S. aureus strains in the community setting and demonstrate the utility of next-generation sequencing to potentially quicken antimicrobial resistance detection and surveillance for targeted interventions.
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Affiliation(s)
- Grace C Lee
- College of Pharmacy, The University of Texas at Austin, San Antonio, TX, USA.,Pharmacotherapy Education and Research Center, School of Medicine, The University of Texas Health Science Center, San Antonio, TX, USA
| | - Steven D Dallas
- Department of Clinical Laboratory Sciences, School of Health Professions, University of Texas Health Science Center, San Antonio, TX, USA
| | - Yufeng Wang
- Department of Biology, The University of Texas San Antonio, San Antonio, TX, USA
| | - Randall J Olsen
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital and Research Institute, Houston, TX, USA
| | - Kenneth A Lawson
- College of Pharmacy, The University of Texas at Austin, San Antonio, TX, USA
| | - James Wilson
- College of Pharmacy, The University of Texas at Austin, San Antonio, TX, USA
| | - Christopher R Frei
- College of Pharmacy, The University of Texas at Austin, San Antonio, TX, USA.,Pharmacotherapy Education and Research Center, School of Medicine, The University of Texas Health Science Center, San Antonio, TX, USA
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117
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Takada H, Yoshikawa H. Essentiality and function of WalK/WalR two-component system: the past, present, and future of research. Biosci Biotechnol Biochem 2018. [PMID: 29514560 DOI: 10.1080/09168451.2018.1444466] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The WalK/WalR two-component system (TCS), originally identified in Bacillus subtilis, is very highly conserved in gram-positive bacteria, including several important pathogens. The WalK/WalR TCS appears to be involved in the growth of most bacterial species encoding it. Previous studies have indicated conserved functions of this system, defining this signal transduction pathway as a crucial regulatory system for cell wall metabolism. Because of such effects on essential functions, this system is considered a potential target for anti-infective therapeutics. In this review, we discuss the role of WalK/WalR TCS in different bacterial cells, focusing on the function of the genes in its regulon as well as the variations in walRK operon structure, its auxiliary proteins, and the composition of its regulon. We also discuss recent experimental data addressing its essential function and the potential type of signal being sensed by B. subtilis. This review also focuses on the potential future research.
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Affiliation(s)
- Hiraku Takada
- Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Tokyo, Japan.,Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan
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118
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Abstract
Antibiotics have saved millions of lives over the past decades. However, the accumulation of so many antibiotic resistance genes by some clinically relevant pathogens has begun to lead to untreatable infections worldwide. The current antibiotic resistance crisis will require greater efforts by governments and the scientific community to increase the research and development of new antibacterial drugs with new mechanisms of action. A major challenge is the identification of novel microbial targets, essential for in vivo growth or pathogenicity, whose inhibitors can overcome the currently circulating resistome of human pathogens. In this article, we focus on the potential high value of bacterial transcriptional regulators as targets for the development of new antibiotics, discussing in depth the molecular role of these regulatory proteins in bacterial physiology and pathogenesis. Recent advances in the search for novel compounds that inhibit the biological activity of relevant transcriptional regulators in pathogenic bacteria are reviewed.
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119
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Foster TJ. Antibiotic resistance in Staphylococcus aureus. Current status and future prospects. FEMS Microbiol Rev 2018; 41:430-449. [PMID: 28419231 DOI: 10.1093/femsre/fux007] [Citation(s) in RCA: 402] [Impact Index Per Article: 67.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/12/2017] [Indexed: 12/11/2022] Open
Abstract
The major targets for antibiotics in staphylococci are (i) the cell envelope, (ii) the ribosome and (iii) nucleic acids. Several novel targets emerged from recent targeted drug discovery programmes including the ClpP protease and FtsZ from the cell division machinery. Resistance can either develop by horizontal transfer of resistance determinants encoded by mobile genetic elements viz plasmids, transposons and the staphylococcal cassette chromosome or by mutations in chromosomal genes. Horizontally acquired resistance can occur by one of the following mechanisms: (i) enzymatic drug modification and inactivation, (ii) enzymatic modification of the drug binding site, (iii) drug efflux, (iv) bypass mechanisms involving acquisition of a novel drug-resistant target, (v) displacement of the drug to protect the target. Acquisition of resistance by mutation can result from (i) alteration of the drug target that prevents the inhibitor from binding, (ii) derepression of chromosomally encoded multidrug resistance efflux pumps and (iii) multiple stepwise mutations that alter the structure and composition of the cell wall and/or membrane to reduce drug access to its target. This review focuses on development of resistance to currently used antibiotics and examines future prospects for new antibiotics and informed use of drug combinations.
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120
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Moradigaravand D, Gouliouris T, Blane B, Naydenova P, Ludden C, Crawley C, Brown NM, Török ME, Parkhill J, Peacock SJ. Within-host evolution of Enterococcus faecium during longitudinal carriage and transition to bloodstream infection in immunocompromised patients. Genome Med 2017; 9:119. [PMID: 29282103 PMCID: PMC5744393 DOI: 10.1186/s13073-017-0507-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 12/07/2017] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Enterococcus faecium is a leading cause of hospital-acquired infection, particularly in the immunocompromised. Here, we use whole genome sequencing of E. faecium to study within-host evolution and the transition from gut carriage to invasive disease. METHODS We isolated and sequenced 180 E. faecium from four immunocompromised patients who developed bloodstream infection during longitudinal surveillance of E. faecium in stool and their immediate environment. RESULTS A phylogenetic tree based on single nucleotide polymorphisms (SNPs) in the core genome of the 180 isolates demonstrated several distinct clones. This was highly concordant with the population structure inferred by Bayesian methods, which contained four main BAPS (Bayesian Analysis of Population Structure) groups. The majority of isolates from each patient resided in a single group, but all four patients also carried minority populations in stool from multiple phylogenetic groups. Bloodstream isolates from each case belonged to a single BAPS group, which differed in all four patients. Analysis of 87 isolates (56 from blood) belonging to a single BAPS group that were cultured from the same patient over 54 days identified 30 SNPs in the core genome (nine intergenic, 13 non-synonymous, eight synonymous), and 250 accessory genes that were variably present. Comparison of these genetic variants in blood isolates versus those from stool or environment did not identify any variants associated with bloodstream infection. The substitution rate for these isolates was estimated to be 128 (95% confidence interval 79.82 181.77) mutations per genome per year, more than ten times higher than previous estimates for E. faecium. Within-patient variation in vancomycin resistance associated with vanA was common and could be explained by plasmid loss, or less often by transposon loss. CONCLUSIONS These findings demonstrate the diversity of E. faecium carriage by individual patients and significant within-host diversity of E. faecium, but do not provide evidence for adaptive genetic variation associated with invasion.
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Affiliation(s)
- Danesh Moradigaravand
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK.
| | - Theodore Gouliouris
- Department of Medicine, University of Cambridge, Box 157, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK.
- Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK.
- Public Health England, Clinical Microbiology and Public Health Laboratory, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
| | - Beth Blane
- Department of Medicine, University of Cambridge, Box 157, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Plamena Naydenova
- Department of Medicine, University of Cambridge, Box 157, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Catherine Ludden
- London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Charles Crawley
- Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Nicholas M Brown
- Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
- Public Health England, Clinical Microbiology and Public Health Laboratory, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - M Estée Török
- Department of Medicine, University of Cambridge, Box 157, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
- Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
- Public Health England, Clinical Microbiology and Public Health Laboratory, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Julian Parkhill
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Sharon J Peacock
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
- Department of Medicine, University of Cambridge, Box 157, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
- London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
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121
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Young BC, Wu CH, Gordon NC, Cole K, Price JR, Liu E, Sheppard AE, Perera S, Charlesworth J, Golubchik T, Iqbal Z, Bowden R, Massey RC, Paul J, Crook DW, Peto TE, Walker AS, Llewelyn MJ, Wyllie DH, Wilson DJ. Severe infections emerge from commensal bacteria by adaptive evolution. eLife 2017; 6. [PMID: 29256859 PMCID: PMC5736351 DOI: 10.7554/elife.30637] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 12/02/2017] [Indexed: 12/23/2022] Open
Abstract
Bacteria responsible for the greatest global mortality colonize the human microbiota far more frequently than they cause severe infections. Whether mutation and selection among commensal bacteria are associated with infection is unknown. We investigated de novo mutation in 1163 Staphylococcus aureus genomes from 105 infected patients with nose colonization. We report that 72% of infections emerged from the nose, with infecting and nose-colonizing bacteria showing parallel adaptive differences. We found 2.8-to-3.6-fold adaptive enrichments of protein-altering variants in genes responding to rsp, which regulates surface antigens and toxin production; agr, which regulates quorum-sensing, toxin production and abscess formation; and host-derived antimicrobial peptides. Adaptive mutations in pathogenesis-associated genes were 3.1-fold enriched in infecting but not nose-colonizing bacteria. None of these signatures were observed in healthy carriers nor at the species-level, suggesting infection-associated, short-term, within-host selection pressures. Our results show that signatures of spontaneous adaptive evolution are specifically associated with infection, raising new possibilities for diagnosis and treatment.
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Affiliation(s)
- Bernadette C Young
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, Oxford, United Kingdom.,Microbiology and Infectious Diseases Department, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Chieh-Hsi Wu
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, Oxford, United Kingdom
| | - N Claire Gordon
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, Oxford, United Kingdom
| | - Kevin Cole
- Department of Infectious Diseases and Microbiology, Royal Sussex County Hospital, Brighton, United Kingdom
| | - James R Price
- Department of Infectious Diseases and Microbiology, Royal Sussex County Hospital, Brighton, United Kingdom.,Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
| | - Elian Liu
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, Oxford, United Kingdom.,Microbiology and Infectious Diseases Department, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Anna E Sheppard
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, Oxford, United Kingdom.,NIHR Health Protection Unit in Healthcare Associated Infections and Antimicrobial Resistance at University of Oxford in partnership with Public Health England, Oxford, United Kingdom
| | - Sanuki Perera
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, Oxford, United Kingdom.,Microbiology and Infectious Diseases Department, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Jane Charlesworth
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, Oxford, United Kingdom
| | - Tanya Golubchik
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, Oxford, United Kingdom
| | - Zamin Iqbal
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Rory Bowden
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Ruth C Massey
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
| | - John Paul
- National Infection Service, Public Health England, London, United Kingdom.,National Institute for Health Research, Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Derrick W Crook
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, Oxford, United Kingdom.,National Infection Service, Public Health England, London, United Kingdom.,National Institute for Health Research, Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Timothy E Peto
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, Oxford, United Kingdom.,National Institute for Health Research, Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - A Sarah Walker
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, Oxford, United Kingdom.,National Institute for Health Research, Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Martin J Llewelyn
- Department of Infectious Diseases and Microbiology, Royal Sussex County Hospital, Brighton, United Kingdom.,Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
| | - David H Wyllie
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, Oxford, United Kingdom.,Centre for Molecular and Cellular Physiology, Jenner Institute, Oxford, United Kingdom
| | - Daniel J Wilson
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, Oxford, United Kingdom.,Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom.,Institute for Emerging Infections, Oxford Martin School, University of Oxford, Oxford, United Kingdom
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122
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Vimberg V, Cavanagh JP, Benada O, Kofroňová O, Hjerde E, Zieglerová L, Balíková Novotná G. Teicoplanin resistance in Staphylococcus haemolyticus is associated with mutations in histidine kinases VraS and WalK. Diagn Microbiol Infect Dis 2017; 90:233-240. [PMID: 29246777 DOI: 10.1016/j.diagmicrobio.2017.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 11/09/2017] [Accepted: 11/11/2017] [Indexed: 10/18/2022]
Abstract
We investigated the genetic basis of glycopeptide resistance in laboratory-derived strains of S. haemolyticus with emphasis on differences between vancomycin and teicoplanin. The genomes of two stable teicoplanin-resistant laboratory mutants selected on vancomycin or teicoplanin were sequenced and compared to parental S. haemolyticus strain W2/124. Only the two non-synonymous mutations, VraS Q289K and WalK V550L were identified. No other mutations or genome rearrangements were detected. Increased cell wall thickness, resistance to lysostaphin-induced lysis and adaptation of cell growth rates specifically to teicoplanin were phenotypes observed in a sequenced strain with the VraS Q289K mutation. Neither of the VraS Q289K and WalK V550L mutations was present in the genomes of 121S. haemolyticus clinical isolates. However, all but two of the teicoplanin resistant strains carried non-synonymous SNPs in vraSRTU and walKR-YycHIJ operons pointing to their importance for the glycopeptide resistance.
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Affiliation(s)
- Vladimir Vimberg
- Institute of Microbiology v. v. i., The Czech Academy of Sciences, Průmyslová 595, Vestec 252 50, Czech Republic
| | - Jorunn Pauline Cavanagh
- Department of Pediatrics, University Hospital of North Norway, Sykehusvegen 38, Tromsø 9019, Norway; Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø 9037, Norway
| | - Oldřich Benada
- Institute of Microbiology v. v. i., The Czech Academy of Sciences, Vídeňská 1083, Prague 142 20, Czech Republic
| | - Olga Kofroňová
- Institute of Microbiology v. v. i., The Czech Academy of Sciences, Vídeňská 1083, Prague 142 20, Czech Republic
| | - Erik Hjerde
- Department of Chemistry, Norstruct, UiT The Arctic University of Norway, Sykhusvegen 23, Tromsø 9019, Norway
| | - Leona Zieglerová
- Institute of Microbiology v. v. i., The Czech Academy of Sciences, Průmyslová 595, Vestec 252 50, Czech Republic
| | - Gabriela Balíková Novotná
- Institute of Microbiology v. v. i., The Czech Academy of Sciences, Průmyslová 595, Vestec 252 50, Czech Republic.
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123
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Characterization of the Mechanisms of Daptomycin Resistance among Gram-Positive Bacterial Pathogens by Multidimensional Lipidomics. mSphere 2017; 2:mSphere00492-17. [PMID: 29242835 PMCID: PMC5729219 DOI: 10.1128/msphere.00492-17] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 11/16/2017] [Indexed: 12/22/2022] Open
Abstract
Previous work suggests that altered lipid metabolism may be associated with daptomycin resistance in Gram-positive pathogens, but lipidomic changes underlying resistance are not fully understood. We performed untargeted lipidomics by using three-dimensional hydrophilic interaction liquid chromatography-ion mobility-mass spectrometry (HILIC-IM-MS) to characterize alterations in the lipidomes of daptomycin-susceptible and -resistant isogenic strain pairs of Enterococcus faecalis, Staphylococcus aureus, and Corynebacterium striatum. We first validated the HILIC-IM-MS method by replicating the expected alterations of phospholipid metabolism in the previously studied E. faecalis strain pairs, such as reduced phosphatidylglycerols (PGs), while also revealing additional changes in cardiolipins (CLs), lysyl-PGs, and glycolipids. Whole-genome sequencing of the S. aureus and C. striatum strains found that daptomycin resistance was associated with mutations in pgsA, which encodes phosphatidylglycerophosphate synthase, as well as mutations in genes affecting fatty acid biosynthesis and cell wall metabolism. Lipidomics revealed significantly decreased levels of PGs, CLs, and amino acid-modified PGs, as well as accumulation of lipids upstream of PGs, such as glycolipids and phosphatidic acids, in the resistant strains. Notably, the glycolipids, diglucosyldiacylglycerols, were significantly elevated in a fatty acid-dependent manner in the daptomycin-resistant S. aureus strain. In daptomycin-resistant C. striatum, which has a unique cell envelope architecture, the glycolipids, glucuronosyldiacylglycerols, and phosphatidylinositols were significantly elevated. These results demonstrate that alteration of lipid metabolism via mutations in pgsA is a common mechanism of daptomycin resistance in two distinct species of Gram-positive bacteria and point to the potential contribution of altered glycolipid and fatty acid compositions to daptomycin resistance. IMPORTANCE This work comprehensively characterizes lipidomic changes underlying daptomycin resistance in three Gram-positive bacterial species, E. faecalis, S. aureus, and C. striatum, by using a novel three-dimensional lipidomics methodology based on advanced mass spectrometry. We demonstrated a number of advantages of our method in comparison with other methods commonly used in the field, such as high molecular specificity, sensitivity, and throughput. Whole-genome sequencing of the S. aureus and C. striatum strains identified mutations in pgsA, which encodes phosphatidylglycerophosphate synthase, in both resistant strains. Lipidomics revealed significantly decreased levels of lipids downstream of PgsA, as well as accumulation of lipids upstream of PgsA in the resistant strains. Furthermore, we found that changes in individual molecular species of each lipid class depend on the their specific fatty acid compositions. The characteristic changes in individual lipid species could be used as biomarkers for identifying underlying resistance mechanisms and for evaluating potential therapies.
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124
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Cardona ST, Choy M, Hogan AM. Essential Two-Component Systems Regulating Cell Envelope Functions: Opportunities for Novel Antibiotic Therapies. J Membr Biol 2017; 251:75-89. [DOI: 10.1007/s00232-017-9995-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 10/20/2017] [Indexed: 01/22/2023]
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125
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García AB, Viñuela-Prieto JM, López-González L, Candel FJ. Correlation between resistance mechanisms in Staphylococcus aureus and cell wall and septum thickening. Infect Drug Resist 2017; 10:353-356. [PMID: 29089777 PMCID: PMC5655128 DOI: 10.2147/idr.s146748] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose The aim of the present study is to examine cell wall and septum thickening of methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), and methicillin- and linezolid-resistant S. aureus (MLRSA) isolates by transmission electron microscopy to correlate the association of resistance mechanisms with major changes in the morphology of membrane or septum. Materials and methods MSSA, MRSA, and MLRSA strains obtained from clinical samples of an outbreak that occurred in 2010 at the Intensive Care Unit of our Hospital were thawed and sown at 37°C in blood agar overnight. After that, they were washed, pelleted, and treated with a fixer solution. Pellets were dehydrated and finally embedded in resin. Transmission electron microscopy was used to characterize cell wall and septum thickening in all isolates. The comparison between the measurements obtained for each group was performed by a Kruskal–Wallis test and a post hoc Dunn–Bonferroni’s pairwise comparison method. Results Differences in cell wall and septum thickness were statistically significant (P<0.001 and P<0.001, respectively) between the three groups. Moreover, significant differences were detected in wall and septum thickness between the MSSA and MRSA strains (P<0.001 and P<0.001, respectively) and between the MSSA and MLRSA strains (P<0.001 and P<0.001, respectively) but not between the MRSA and MLRSA strains (P=0.386 and P=0.117). Conclusion In this analysis, we correlate the resistance mediated by alterations in the cell membrane of S. aureus (methicillin-resistant, for example) with a greater thickness of the wall or septum. The resistance added to linezolid did not determine significant changes in the characteristics of the wall or septum with respect to those strains resistant only to methicillin.
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Affiliation(s)
- Ana Belén García
- Department of Clinical Microbiology, Hospital Clínico San Carlos, Complutense University, Madrid, Spain
| | | | - Laura López-González
- Department of Clinical Microbiology, Hospital Clínico San Carlos, Complutense University, Madrid, Spain
| | - Francisco Javier Candel
- Department of Clinical Microbiology, Hospital Clínico San Carlos, Complutense University, Madrid, Spain.,Health Research Institute, Hospital Universitario San Carlos, Madrid, Spain
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126
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Mak S, Nodwell JR. Actinorhodin is a redox-active antibiotic with a complex mode of action against Gram-positive cells. Mol Microbiol 2017; 106:597-613. [PMID: 28906045 DOI: 10.1111/mmi.13837] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2017] [Indexed: 11/29/2022]
Abstract
Actinorhodin is a blue-pigmented, redox-active secondary metabolite that is produced by the bacterium Streptomyces coelicolor. Although actinorhodin has been used as a model compound for studying secondary metabolism, its biological activity is not well understood. Indeed, redox-active antibiotics in general have not been widely investigated at the mechanistic level. In this work, we have conducted a comprehensive chemical genetic investigation of actinorhodin's antibacterial effect on target organisms. We find that actinorhodin is a potent, bacteriostatic, pH-responsive antibiotic. Cells activate at least three stress responses in the presence of actinorhodin, including those responsible for managing oxidative damage, protein damage and selected forms of DNA damage. We find that mutations in the Staphylococcus aureus walRKHI operon can confer low-level resistance to actinorhodin, indicating possible targeting of the cell envelope. Our study indicates a complex mechanism of action, involving multiple molecular targets, that is distinct from other antibiotics.
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Affiliation(s)
- Stefanie Mak
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Justin R Nodwell
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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127
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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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128
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Cameron DR, Lin YH, Trouillet-Assant S, Tafani V, Kostoulias X, Mouhtouris E, Skinner N, Visvanathan K, Baines SL, Howden B, Monk IR, Laurent F, Stinear TP, Howden BP, Peleg AY. Vancomycin-intermediate Staphylococcus aureus isolates are attenuated for virulence when compared with susceptible progenitors. Clin Microbiol Infect 2017; 23:767-773. [PMID: 28396035 DOI: 10.1016/j.cmi.2017.03.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 03/29/2017] [Accepted: 03/30/2017] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Vancomycin-intermediate Staphylococcus aureus (VISA) is associated with genetic changes that may also impact upon pathogenicity. In the current study, we compared the virulence of clinical VISA strains with their isogenic vancomycin-susceptible progenitors (VSSA). METHODS Production of the critical virulence protein, α toxin, was assessed using Western blot analysis and was correlated to agr activity using a bioluminescent agr-reporter. Cytotoxicity and intracellular persistence were compared ex vivo for VSSA and VISA within non-professional phagocytes (NPP). Virulence and host immune responses were further explored in vivo using a murine model of bacteraemia. RESULTS VISA isolates produced up to 20-fold less α toxin compared with VSSA, and this was corroborated by either loss of agr activity due to agr mutation, or altered agr activity in the absence of mutation. VISA were less cytotoxic towards NPP and were associated with enhanced intracellular persistence, suggesting that NPP may act as a reservoir for VISA. Infection with VSSA strains produced higher mortality in a murine bacteraemia model (≥90% 7-day mortality) compared with infection with VISA isolates (20% to 50%, p <0.001). Mice infected with VISA produced a dampened immune response (4.6-fold reduction in interleukin-6, p <0.001) and persistent organ bacterial growth was observed for VISA strains out to 7 days. CONCLUSIONS These findings highlight the remarkable adaptability of S. aureus, whereby, in addition to having reduced antibiotic susceptibility, VISA alter the expression of pathogenic factors to circumvent the host immune response to favour persistent infection over acute virulence.
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Affiliation(s)
- D R Cameron
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Australia
| | - Y-H Lin
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute of Infection & Immunity, Australia
| | - S Trouillet-Assant
- Department of Microbiology, French National Reference Centre for Staphylococci, Hospices Civils de Lyon, International Centre of Infectiology Research, France
| | - V Tafani
- Department of Microbiology, French National Reference Centre for Staphylococci, Hospices Civils de Lyon, International Centre of Infectiology Research, France
| | - X Kostoulias
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Australia
| | - E Mouhtouris
- Department of Surgery, The University of Melbourne, Australia
| | - N Skinner
- Department of Medicine, The University of Melbourne, Australia
| | - K Visvanathan
- Department of Medicine, The University of Melbourne, Australia
| | - S L Baines
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute of Infection & Immunity, Australia
| | - B Howden
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute of Infection & Immunity, Australia
| | - I R Monk
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute of Infection & Immunity, Australia
| | - F Laurent
- Department of Microbiology, French National Reference Centre for Staphylococci, Hospices Civils de Lyon, International Centre of Infectiology Research, France
| | - T P Stinear
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute of Infection & Immunity, Australia
| | - B P Howden
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute of Infection & Immunity, Australia; Infectious Diseases and Microbiology Departments, Austin Health, Australia.
| | - A Y Peleg
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Australia; Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Australia.
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129
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Correspondence: Spontaneous secondary mutations confound analysis of the essential two-component system WalKR in Staphylococcus aureus. Nat Commun 2017; 8:14403. [PMID: 28165454 PMCID: PMC5303874 DOI: 10.1038/ncomms14403] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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130
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Fyhrquist P, Virjamo V, Hiltunen E, Julkunen-Tiitto R. Epidihydropinidine, the main piperidine alkaloid compound of Norway spruce (Picea abies) shows promising antibacterial and anti-Candida activity. Fitoterapia 2017; 117:138-146. [PMID: 28163074 DOI: 10.1016/j.fitote.2017.01.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 01/23/2017] [Accepted: 01/29/2017] [Indexed: 01/26/2023]
Abstract
This study reports for the first time promising antibacterial and antifungal effects of epidihydropinidine, the major piperidine alkaloid in the needles and bark of Norway spruce, Picea abies (L.) Karsten. Epidihydropinidine was growth inhibitory against all bacterial and fungal strains used in our investigation, showing the lowest MIC value of 5.37μg/mL against Pseudomonas aeruginosa, Enterococcus faecalis, Candida glabrata and C. albicans. Epidihydropinidine was nearly three times more active than tetracycline against P. aeruginosa and E. faecalis. Promising antibacterial effects were also recorded against Staphylococcus aureus and Bacillus cereus (MIC 10.75μg/mL) as well as against Salmonella enterica (MIC and MBC 43μg/mL). Our preliminary results suggest that epidihydropinidine as well related alkaloids of Norway spruce could be powerful candidates for new antibiotics and for preventing food spoilage.
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Affiliation(s)
- Pia Fyhrquist
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, P.O. Box 56, FIN-00014, University of Helsinki, Finland.
| | - Virpi Virjamo
- Natural Product Research Laboratory, Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, Joensuu, Finland
| | - Eveliina Hiltunen
- Natural Product Research Laboratory, Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, Joensuu, Finland
| | - Riitta Julkunen-Tiitto
- Natural Product Research Laboratory, Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, Joensuu, Finland
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131
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Buultjens AH, Lam MMC, Ballard S, Monk IR, Mahony AA, Grabsch EA, Grayson ML, Pang S, Coombs GW, Robinson JO, Seemann T, Johnson PDR, Howden BP, Stinear TP. Evolutionary origins of the emergent ST796 clone of vancomycin resistant Enterococcus faecium. PeerJ 2017; 5:e2916. [PMID: 28149688 PMCID: PMC5267571 DOI: 10.7717/peerj.2916] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 12/16/2016] [Indexed: 12/03/2022] Open
Abstract
From early 2012, a novel clone of vancomycin resistant Enterococcus faecium (assigned the multi locus sequence type ST796) was simultaneously isolated from geographically separate hospitals in south eastern Australia and New Zealand. Here we describe the complete genome sequence of Ef_aus0233, a representative ST796 E. faecium isolate. We used PacBio single molecule real-time sequencing to establish a high quality, fully assembled genome comprising a circular chromosome of 2,888,087 bp and five plasmids. Comparison of Ef_aus0233 to other E. faecium genomes shows Ef_aus0233 is a member of the epidemic hospital-adapted lineage and has evolved from an ST555-like ancestral progenitor by the accumulation or modification of five mosaic plasmids and five putative prophage, acquisition of two cryptic genomic islands, accrued chromosomal single nucleotide polymorphisms and a 80 kb region of recombination, also gaining Tn1549 and Tn916, transposons conferring resistance to vancomycin and tetracycline respectively. The genomic dissection of this new clone presented here underscores the propensity of the hospital E. faecium lineage to change, presumably in response to the specific conditions of hospital and healthcare environments.
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Affiliation(s)
- Andrew H Buultjens
- Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne , Melbourne , Victoria , Australia
| | - Margaret M C Lam
- Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne , Melbourne , Victoria , Australia
| | - Susan Ballard
- Microbiology Diagnostic Unit, Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne , Melbourne , Victoria , Australia
| | - Ian R Monk
- Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne , Melbourne , Victoria , Australia
| | - Andrew A Mahony
- Infectious Diseases Department, Austin Health , Heidelberg , Victoria , Australia
| | - Elizabeth A Grabsch
- Infectious Diseases Department, Austin Health , Heidelberg , Victoria , Australia
| | - M Lindsay Grayson
- Infectious Diseases Department, Austin Health , Heidelberg , Victoria , Australia
| | - Stanley Pang
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia; Department of Microbiology, Pathwest Laboratory Medicine-WA, Fiona Stanley Hospital, Murdoch, Western Australia, Australia
| | - Geoffrey W Coombs
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia; Department of Microbiology, Pathwest Laboratory Medicine-WA, Fiona Stanley Hospital, Murdoch, Western Australia, Australia
| | - J Owen Robinson
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia; Department of Infectious Diseases, Fiona Stanley Hospital, Murdoch, Western Australia, Australia
| | - Torsten Seemann
- Victorian Life Sciences Computation Initiative, University of Melbourne , Carlton , Victoria , Australia
| | - Paul D R Johnson
- Infectious Diseases Department, Austin Health, Heidelberg, Victoria, Australia; Department of Medicine, University of Melbourne, Heidelberg, Victoria, Australia
| | - Benjamin P Howden
- Microbiology Diagnostic Unit, Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne , Melbourne , Victoria , Australia
| | - Timothy P Stinear
- Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne , Melbourne , Victoria , Australia
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132
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In Vitro Tolerance of Drug-Naive Staphylococcus aureus Strain FDA209P to Vancomycin. Antimicrob Agents Chemother 2017; 61:AAC.01154-16. [PMID: 27855063 PMCID: PMC5278750 DOI: 10.1128/aac.01154-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 11/03/2016] [Indexed: 12/26/2022] Open
Abstract
The mechanisms underlying bacterial tolerance to antibiotics are unclear. A possible adaptation strategy was explored by exposure of drug-naive methicillin-susceptible Staphylococcus aureus strain FDA209P to vancomycin in vitro. Strains surviving vancomycin treatment (vancomycin survivor strains), which appeared after 96 h of exposure, were slow-growing derivatives of the parent strain. Although the vancomycin MICs for the survivor strains were within the susceptible range, the cytokilling effects of vancomycin at 20-fold the MIC were significantly lower for the survivor strains than for the parent strain. Whole-genome sequencing demonstrated that ileS, encoding isoleucyl-tRNA synthetase (IleRS), was mutated in two of the three vancomycin survivor strains. The IleRS Y723H mutation is located close to the isoleucyl-tRNA contact site and potentially affects the affinity of IleRS binding to isoleucyl-tRNA, thereby inhibiting protein synthesis and leading to vancomycin tolerance. Introduction of the mutation encoding IleRS Y723H into FDA209P by allelic replacement successfully transferred the vancomycin tolerance phenotype. We have identified mutation of ileS to be one of the bona fide genetic events leading to the acquisition of vancomycin tolerance in S. aureus, potentially acting via inhibition of the function of IleRS.
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133
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Wang Y, Li X, Jiang L, Han W, Xie X, Jin Y, He X, Wu R. Novel Mutation Sites in the Development of Vancomycin- Intermediate Resistance in Staphylococcus aureus. Front Microbiol 2017; 7:2163. [PMID: 28119680 PMCID: PMC5222870 DOI: 10.3389/fmicb.2016.02163] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 12/22/2016] [Indexed: 11/13/2022] Open
Abstract
Increased use of vancomycin has led to the emergence of vancomycin-intermediate Staphylococcus aureus (VISA). To investigate the mechanism of VISA development, 39 methicillin-susceptible strains and 3 MRSA strains were treated with vancomycin to induce non-susceptibility, and mutations in six genes were analyzed. All the strains were treated with vancomycin in vitro for 60 days. MICs were determined by the agar dilution and E-test methods. Vancomycin was then removed to assess the stability of VISA strains and mutations. Following 60 days of vancomycin treatment in vitro, 29/42 VISA strains were generated. The complete sequences of rpoB, vraS, graR, graS, walK, and walR were compared with those in the parental strains. Seven missense mutations including four novel mutations (L466S in rpoB, R232K in graS, I594M in walk, and A111T in walR) were detected frequently in strains with vancomycin MIC ≥ 12 μg/mL. Jonckheere-Terpstra trend test indicated these mutations might play an important role during VISA evolution. After the vancomycin treatment, strains were passaged to vancomycin-free medium for another 60 days, and the MICs of all strains decreased. Our results suggest that rpoB, graS, walk, and walR are more important than vraS and graR in VISA development.
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Affiliation(s)
- Yubing Wang
- College of Biological Sciences and Biotechnology, Beijing Forestry University Beijing, China
| | - Xiaoli Li
- College of Biological Sciences and Biotechnology, Beijing Forestry University Beijing, China
| | - Libo Jiang
- College of Biological Sciences and Biotechnology, Beijing Forestry UniversityBeijing, China; Center for Computational Biology, Beijing Forestry UniversityBeijing, China
| | - Wentao Han
- College of Biological Sciences and Biotechnology, Beijing Forestry University Beijing, China
| | - Xiangming Xie
- College of Biological Sciences and Biotechnology, Beijing Forestry University Beijing, China
| | - Yi Jin
- College of Biological Sciences and Biotechnology, Beijing Forestry UniversityBeijing, China; Center for Computational Biology, Beijing Forestry UniversityBeijing, China
| | - Xiaoqing He
- College of Biological Sciences and Biotechnology, Beijing Forestry UniversityBeijing, China; Center for Computational Biology, Beijing Forestry UniversityBeijing, China
| | - Rongling Wu
- College of Biological Sciences and Biotechnology, Beijing Forestry UniversityBeijing, China; Center for Computational Biology, Beijing Forestry UniversityBeijing, China; Center for Statistical Genetics, Pennsylvania State UniversityHershey, PA, USA
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134
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The action mechanism of daptomycin. Bioorg Med Chem 2016; 24:6253-6268. [DOI: 10.1016/j.bmc.2016.05.052] [Citation(s) in RCA: 130] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/20/2016] [Accepted: 05/26/2016] [Indexed: 11/15/2022]
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135
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Zeng D, Debabov D, Hartsell TL, Cano RJ, Adams S, Schuyler JA, McMillan R, Pace JL. Approved Glycopeptide Antibacterial Drugs: Mechanism of Action and Resistance. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a026989. [PMID: 27663982 DOI: 10.1101/cshperspect.a026989] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The glycopeptide antimicrobials are a group of natural product and semisynthetic glycosylated peptides that show antibacterial activity against Gram-positive organisms through inhibition of cell-wall synthesis. This is achieved primarily through binding to the d-alanyl-d-alanine terminus of the lipid II bacterial cell-wall precursor, preventing cross-linking of the peptidoglycan layer. Vancomycin is the foundational member of the class, showing both clinical longevity and a still preferential role in the therapy of methicillin-resistant Staphylococcus aureus and of susceptible Enterococcus spp. Newer lipoglycopeptide derivatives (telavancin, dalbavancin, and oritavancin) were designed in a targeted fashion to increase antibacterial activity, in some cases through secondary mechanisms of action. Resistance to the glycopeptides emerged in delayed fashion and occurs via a spectrum of chromosome- and plasmid-associated elements that lead to structural alteration of the bacterial cell-wall precursor substrates.
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Affiliation(s)
- Daina Zeng
- Agile Sciences, Raleigh, North Carolina 27606
| | | | - Theresa L Hartsell
- Department of Anesthesiology/Critical Care Medicine, The Johns Hopkins School of Medicine and Nursing, Baltimore, Maryland 21287
| | - Raul J Cano
- ATCC Center for Translational Microbiology, Union, New Jersey 07083.,Biological Sciences Department, California Polytechnic State University, San Luis Obispo, California 93407
| | - Stacy Adams
- Center for Skin Biology, GlaxoSmithKline, Durham, North Carolina 27703
| | | | - Ronald McMillan
- ATCC Center for Translational Microbiology, Union, New Jersey 07083
| | - John L Pace
- ATCC Center for Translational Microbiology, Union, New Jersey 07083.,STEM Program, Kean University, Union, New Jersey 07083.,Biomanufacturing Research Institute and Technology Enterprise, North Carolina Central University, Durham, North Carolina 27707
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136
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Miller WR, Bayer AS, Arias CA. Mechanism of Action and Resistance to Daptomycin in Staphylococcus aureus and Enterococci. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a026997. [PMID: 27580748 DOI: 10.1101/cshperspect.a026997] [Citation(s) in RCA: 134] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Lipopeptides are natural product antibiotics that consist of a peptide core with a lipid tail with a diverse array of target organisms and mechanisms of action. Daptomycin (DAP) is an example of these compounds with specific activity against Gram-positive organisms. DAP has become increasingly important to combat infections caused by Gram-positive bacteria because of the presence of multidrug resistance in these organisms, particularly in methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). However, emergence of resistance to DAP during therapy is a well-described phenomenon that threatens the clinical use of this antibiotic, limiting further the therapeutic options against both MRSA and VRE. This work will review the historical aspects of the development of DAP, as well as the current knowledge on its mechanism of action and pathways to resistance in a clinically relevant context.
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Affiliation(s)
- William R Miller
- University of Texas Medical School at Houston, Department of Internal Medicine, Division of Infectious Diseases, Houston, Texas 77030
| | - Arnold S Bayer
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California 90502.,David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Cesar A Arias
- University of Texas Medical School at Houston, Department of Internal Medicine, Division of Infectious Diseases, Houston, Texas 77030.,Department of Microbiology and Molecular Genetics, Houston, Texas 77030.,Molecular Genetics and Antimicrobial Resistance Unit, Universidad El Bosque, Bogota, Colombia.,International Center for Microbial Genomics, Universidad El Bosque, Bogota, Colombia
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137
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Hu Q, Peng H, Rao X. Molecular Events for Promotion of Vancomycin Resistance in Vancomycin Intermediate Staphylococcus aureus. Front Microbiol 2016; 7:1601. [PMID: 27790199 PMCID: PMC5062060 DOI: 10.3389/fmicb.2016.01601] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 09/26/2016] [Indexed: 12/14/2022] Open
Abstract
Vancomycin has been used as the last resort in the clinical treatment of serious Staphylococcus aureus infections. Vancomycin-intermediate S. aureus (VISA) was discovered almost two decades ago. Aside from the vancomycin-intermediate phenotype, VISA strains from the clinic or laboratory exhibited common characteristics, such as thickened cell walls, reduced autolysis, and attenuated virulence. However, the genetic mechanisms responsible for the reduced vancomycin susceptibility in VISA are varied. The comparative genomics of vancomycin-susceptible S. aureus (VSSA)/VISA pairs showed diverse genetic mutations in VISA; only a small number of these mutations have been experimentally verified. To connect the diversified genotypes and common phenotypes in VISA, we reviewed the genetic alterations in the relative determinants, including mutations in the vraTSR, graSR, walKR, stk1/stp1, rpoB, clpP, and cmk genes. Especially, we analyzed the mechanism through which diverse mutations mediate vancomycin resistance. We propose a unified model that integrates diverse gene functions and complex biochemical processes in VISA upon the action of vancomycin.
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Affiliation(s)
- Qiwen Hu
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Huagang Peng
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
| | - Xiancai Rao
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University Chongqing, China
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138
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Giulieri SG, Holmes NE, Stinear TP, Howden BP. Use of bacterial whole-genome sequencing to understand and improve the management of invasive Staphylococcus aureus infections. Expert Rev Anti Infect Ther 2016; 14:1023-1036. [PMID: 27626511 DOI: 10.1080/14787210.2016.1233815] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Management of invasive Staphylococcus aureus infections is complex. Dramatic improvements in bacterial whole genome sequencing (WGS) offer new opportunities for personalising the treatment of S. aureus infections. Areas covered: We address recent achievements in S. aureus genomics, describe genetic determinants of antibiotic resistance and summarise studies that have defined molecular characteristics associated with risk and outcome of S. aureus invasive infections. Potential clinical use of WGS for resistance prediction, infection outcome stratification and management of persistent /relapsing infections is critically discussed. Expert commentary: WGS is not only providing invaluable information to track the emergence and spread of important S. aureus clones, but also allows rapid determination of resistance genotypes in the clinical environment. An evolving opportunity is to infer clinically important outcomes and optimal therapeutic approaches from widely available S. aureus genome data, with the goal of individualizing management of invasive S. aureus infections.
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Affiliation(s)
- Stefano G Giulieri
- a Microbiological Diagnostic Unit Public Health Laboratory , Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne , Melbourne , Australia.,b Infectious Diseases Service , Department of Medicine, Lausanne University Hospital , Lausanne , Switzerland
| | - Natasha E Holmes
- c Infectious Diseases Department , Austin Health , Heidelberg , Australia
| | - Timothy P Stinear
- d Doherty Applied Microbial Genomics , Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne , Melbourne , Australia.,e Department of Microbiology and Immunology , The University of Melbourne at the Peter Doherty Institute for Infection and Immunity , Melbourne , Australia
| | - Benjamin P Howden
- a Microbiological Diagnostic Unit Public Health Laboratory , Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne , Melbourne , Australia.,c Infectious Diseases Department , Austin Health , Heidelberg , Australia.,e Department of Microbiology and Immunology , The University of Melbourne at the Peter Doherty Institute for Infection and Immunity , Melbourne , Australia
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139
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Cameron DR, Jiang JH, Kostoulias X, Foxwell DJ, Peleg AY. Vancomycin susceptibility in methicillin-resistant Staphylococcus aureus is mediated by YycHI activation of the WalRK essential two-component regulatory system. Sci Rep 2016; 6:30823. [PMID: 27600558 PMCID: PMC5013275 DOI: 10.1038/srep30823] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 06/09/2016] [Indexed: 02/01/2023] Open
Abstract
The treatment of infections caused by methicillin-resistant Staphylococcus aureus is complicated by the emergence of strains with intermediate-level resistance to vancomycin (termed VISA). We have characterised a molecular pathway involved in the in vivo evolution of VISA mediated by the regulatory proteins YycH and YycI. In contrast to their function in other bacterial species, we report a positive role for these auxiliary proteins in regulation of the two-component regulator WalRK. Transcriptional profiling of yycH and yycI deletion mutants revealed downregulation of the ‘WalRK regulon’ including cell wall hydrolase genes atlA and sle1, with functional autolysis assays supporting these data by showing an impaired autolytic phenotype for each deletion strain. Using bacterial-two hybrid assays, we showed that YycH and YycI interact, and that YycHI also interacts with the sensor kinase WalK, forming a ternary protein complex. Mutation to YycH or YycI associated with clinical VISA strains had a deleterious impact on the YycHI/WalK complex, suggesting that the interaction is important for the regulation of WalRK. Taken together, we have described a novel antibiotic resistance strategy for the human pathogen S. aureus, whereby YycHI mutations are selected for in vivo leading to reduced WalRK activation, impaired cell wall turnover and ultimately reduced vancomycin efficacy.
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Affiliation(s)
- David R Cameron
- Department of Microbiology, Monash University, Melbourne, Australia
| | - Jhih-Hang Jiang
- Department of Microbiology, Monash University, Melbourne, Australia
| | - Xenia Kostoulias
- Department of Microbiology, Monash University, Melbourne, Australia
| | - Daniel J Foxwell
- Department of Microbiology, Monash University, Melbourne, Australia
| | - Anton Y Peleg
- Department of Microbiology, Monash University, Melbourne, Australia.,Department of Infectious Diseases, Alfred Hospital and Monash University, Melbourne, Australia
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140
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Kim JW, Kim HK, Kang GS, Kim IH, Kim HS, Lee YS, Yoo JI. The SAV1322 gene from Staphylococcus aureus: genomic and proteomic approaches to identification and characterization of gene function. BMC Microbiol 2016; 16:206. [PMID: 27599615 PMCID: PMC5013637 DOI: 10.1186/s12866-016-0824-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 08/29/2016] [Indexed: 11/18/2022] Open
Abstract
Background Bacterial two-component regulatory systems (TCRS) are associated with the expression of virulence factors and antibiotic susceptibility. In Staphylococcus aureus, 16 TCRS types have been identified. The histidine kinase/response regulator SAV1321/SAV1322 in the S. aureus shares considerable homology with the TCRS DesKR in Bacillus subtilis. However, a function for the SAV1322 locus has not yet been assigned. Results Deletion of the SAV1322 locus in S. aureus results in reduced growth when cultured under low (25 °C) and high (46 °C) temperature conditions. The sav1322 deletion mutant is more tolerant to oxidative stress in vitro and is less pathogenic in a murine infection model when compared with wild-type parent strain Mu50. Furthermore, the sav1322 mutant exhibits lower MICs for gentimicin, tetracyclines and glycopeptides, increased autolysis, and a thinner cell wall when compared with the wild-type strain. Microarray and proteomic analyses show that the expression of cell-wall-associated genes glmS and murZ are lower, and the expression of heat shock and stress-related genes (hrcA, ctsR, dnaK, dnaJ, grpE, clpB, and clpC) are higher in the sav1322 mutant when compared with the wild-type strain. In addition, the sav1322 mutant displays altered expression of proteins involved in carbohydrate/energy metabolism, cell wall metabolism, and stress or heat shock response, as well as other metabolic processes including lipid metabolism, amino acid biosynthesis, purine or pyrimidine metabolism, transcription, and protein biosynthesis. Conclusions The S. aureus SAV1322 locus plays a pronounced role in temperature adaptation, antibiotic resistance, and virulence by regulating a wide range of genes and proteins involved in metabolism and stress tolerance. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0824-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jung Wook Kim
- Division of Antimicrobial Resistance, Center for Infectious Diseases, National Research Institute of Health, Centers for Disease Control and Prevention, Cheongju, South Korea
| | - Hyun-Kyung Kim
- Division of Antimicrobial Resistance, Center for Infectious Diseases, National Research Institute of Health, Centers for Disease Control and Prevention, Cheongju, South Korea
| | - Gi Su Kang
- Division of Antimicrobial Resistance, Center for Infectious Diseases, National Research Institute of Health, Centers for Disease Control and Prevention, Cheongju, South Korea
| | - Il-Hwan Kim
- Division of Antimicrobial Resistance, Center for Infectious Diseases, National Research Institute of Health, Centers for Disease Control and Prevention, Cheongju, South Korea
| | - Hwa Su Kim
- Division of Antimicrobial Resistance, Center for Infectious Diseases, National Research Institute of Health, Centers for Disease Control and Prevention, Cheongju, South Korea
| | - Yeong Seon Lee
- Division of Antimicrobial Resistance, Center for Infectious Diseases, National Research Institute of Health, Centers for Disease Control and Prevention, Cheongju, South Korea
| | - Jae Il Yoo
- Division of Antimicrobial Resistance, Center for Infectious Diseases, National Research Institute of Health, Centers for Disease Control and Prevention, Cheongju, South Korea. .,Korea National Research Institute of Health, Osong Health Technology Administration Complex, 187, Osongsaengmyeong2-ro, Osong-eup, Heungdeok-gu, Cheongju-si, Chungcheongbuk-do, 363-700, South Korea.
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141
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Mohedano ML, Amblar M, de la Fuente A, Wells JM, López P. The Response Regulator YycF Inhibits Expression of the Fatty Acid Biosynthesis Repressor FabT in Streptococcus pneumoniae. Front Microbiol 2016; 7:1326. [PMID: 27610104 PMCID: PMC4996995 DOI: 10.3389/fmicb.2016.01326] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/11/2016] [Indexed: 11/25/2022] Open
Abstract
The YycFG (also known as WalRK, VicRK, MicAB, or TCS02) two-component system (TCS) is highly conserved among Gram-positive bacteria with a low G+C content. In Streptococcus pneumoniae the YycF response regulator has been reported to be essential due to its control of pcsB gene expression. Previously we showed that overexpression of yycF in S. pneumoniae TIGR4 altered the transcription of genes involved in cell wall metabolism and fatty acid biosynthesis, giving rise to anomalous cell division and increased chain length of membrane fatty acids. Here, we have overexpressed the yycFG system in TIGR4 wild-type strain and yycF in a TIGR4 mutant depleted of YycG, and analyzed their effects on expression of proteins involved in fatty acid biosynthesis during activation of the TCS. We demonstrate that transcription of the fab genes and levels of their products were only altered in the YycF overexpressing strain, indicating that the unphosphorylated form of YycF is involved in the regulation of fatty acid biosynthesis. In addition, DNA-binding assays and in vitro transcription experiments with purified YycF and the promoter region of the FabTH-acp operon support a direct inhibition of transcription of the FabT repressor by YycF, thus confirming the role of the unphosphorylated form in transcriptional regulation.
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Affiliation(s)
- Maria L Mohedano
- Laboratorio de Biología Molecular de Bacterias Gram positivas, Departamento de Microbiología Molecular y Biología de las Infecciones, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas Madrid, Spain
| | - Mónica Amblar
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III Majadahonda, Spain
| | - Alicia de la Fuente
- Laboratorio de Biología Molecular de Bacterias Gram positivas, Departamento de Microbiología Molecular y Biología de las Infecciones, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas Madrid, Spain
| | - Jerry M Wells
- Host-Microbe Interactomics, Animal Sciences Department, University of Wageningen Wageningen, Netherlands
| | - Paloma López
- Laboratorio de Biología Molecular de Bacterias Gram positivas, Departamento de Microbiología Molecular y Biología de las Infecciones, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas Madrid, Spain
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142
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Abstract
Staphylococcus aureus is a major human pathogen and an important cause of livestock infections. The first S. aureus genomes to be published, 15 years ago, provided the first view of genome structure and gene content. Since then, thousands of genomes from a wide array of strains from different sources have been sequenced. Comparison of these sequences has resulted in broad insights into population structure, bacterial evolution, clone emergence and expansion, and the molecular basis of niche adaptation. Furthermore, this information is now being applied clinically in outbreak investigations to inform infection control measures and to determine appropriate treatment regimens. In this review, we summarize some of the broad insights into S. aureus biology gained from the analysis of genomes and discuss future directions and opportunities in this dynamic field of research.
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Affiliation(s)
- J Ross Fitzgerald
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, United Kingdom;
| | - Matthew T G Holden
- School of Medicine, University of St. Andrews, St. Andrews, Fife KY16 9S5, United Kingdom;
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143
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Charretier Y, Schrenzel J. Mass spectrometry methods for predicting antibiotic resistance. Proteomics Clin Appl 2016; 10:964-981. [PMID: 27312049 DOI: 10.1002/prca.201600041] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/09/2016] [Accepted: 06/13/2016] [Indexed: 11/10/2022]
Abstract
Developing elaborate techniques for clinical applications can be a complicated process. Whole-cell MALDI-TOF MS revolutionized reliable microorganism identification in clinical microbiology laboratories and is now replacing phenotypic microbial identification. This technique is a generic, accurate, rapid, and cost-effective growth-based method. Antibiotic resistance keeps emerging in environmental and clinical microorganisms, leading to clinical therapeutic challenges, especially for Gram-negative bacteria. Antimicrobial susceptibility testing is used to reliably predict antimicrobial success in treating infection, but it is inherently limited by the need to isolate and grow cultures, delaying the application of appropriate therapies. Antibiotic resistance prediction by growth-independent methods is expected to reduce the turnaround time. Recently, the potential of next-generation sequencing and microarrays in predicting microbial resistance has been demonstrated, and this review evaluates the potential of MS in this field. First, technological advances are described, and the possibility of predicting antibiotic resistance by MS is then illustrated for three prototypical human pathogens: Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Clearly, MS methods can identify antimicrobial resistance mediated by horizontal gene transfers or by mutations that affect the quantity of a gene product, whereas antimicrobial resistance mediated by target mutations remains difficult to detect.
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Affiliation(s)
- Yannick Charretier
- Genomic Research Laboratory, Division of Infectious Diseases, Geneva University Hospitals.
| | - Jacques Schrenzel
- Genomic Research Laboratory, Division of Infectious Diseases, Geneva University Hospitals
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144
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Population Genomics of Reduced Vancomycin Susceptibility in Staphylococcus aureus. mSphere 2016; 1:mSphere00094-16. [PMID: 27446992 PMCID: PMC4954867 DOI: 10.1128/msphere.00094-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 06/23/2016] [Indexed: 01/22/2023] Open
Abstract
The increased prevalence of vancomycin-intermediate Staphylococcus aureus (VISA) is an emerging health care threat. Genome-based comparative methods hold great promise to uncover the genetic basis of the VISA phenotype, which remains obscure. S. aureus isolates were collected from a single individual that presented with recurrent staphylococcal bacteremia at three time points, and the isolates showed successively reduced levels of vancomycin susceptibility. A population genomic approach was taken to compare patient S. aureus isolates with decreasing vancomycin susceptibility across the three time points. To do this, patient isolates were sequenced to high coverage (~500×), and sequence reads were used to model site-specific allelic variation within and between isolate populations. Population genetic methods were then applied to evaluate the overall levels of variation across the three time points and to identify individual variants that show anomalous levels of allelic change between populations. A successive reduction in the overall levels of population genomic variation was observed across the three time points, consistent with a population bottleneck resulting from antibiotic treatment. Despite this overall reduction in variation, a number of individual mutations were swept to high frequency in the VISA population. These mutations were implicated as potentially involved in the VISA phenotype and interrogated with respect to their functional roles. This approach allowed us to identify a number of mutations previously implicated in VISA along with allelic changes within a novel class of genes, encoding LPXTG motif-containing cell-wall-anchoring proteins, which shed light on a novel mechanistic aspect of vancomycin resistance. IMPORTANCE The emergence and spread of antibiotic resistance among bacterial pathogens are two of the gravest threats to public health facing the world today. We report the development and application of a novel population genomic technique aimed at uncovering the evolutionary dynamics and genetic determinants of antibiotic resistance in Staphylococcus aureus. This method was applied to S. aureus cultures isolated from a single patient who showed decreased susceptibility to the vancomycin antibiotic over time. Our approach relies on the increased resolution afforded by next-generation genome-sequencing technology, and it allowed us to discover a number of S. aureus mutations, in both known and novel gene targets, which appear to have evolved under adaptive pressure to evade vancomycin mechanisms of action. The approach we lay out in this work can be applied to resistance to any number of antibiotics across numerous species of bacterial pathogens.
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145
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Kim T, Choi J, Lee S, Yeo KJ, Cheong HK, Kim KK. Structural Studies on the Extracellular Domain of Sensor Histidine Kinase YycG from Staphylococcus aureus and Its Functional Implications. J Mol Biol 2016; 428:3074-89. [PMID: 27389096 DOI: 10.1016/j.jmb.2016.06.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 06/15/2016] [Accepted: 06/27/2016] [Indexed: 01/14/2023]
Abstract
Bacterial two-component signal transduction systems are used to adapt to fluctuations in the environment. YycG, a key two-component histidine kinase in Staphylococcus aureus, plays an essential role in cell viability and regulates cell wall metabolism, biofilm formation, virulence, and antibiotic resistance. For these reasons, YycG is considered a compelling target for the development of novel antibiotics. However, to date, the signaling mechanism of YycG and its stimulus are poorly understood mainly because of a lack of structural information on YycG. To address this deficiency, we determined the crystal structure of the extracellular domain of S. aureus YycG (YycGex) at 2.0-Å resolution. The crystal structure indicated two subunits with an extracellular Per-Arnt-Sim (PAS) topology packed into a dimer with interloop interactions. Disulfide scanning using cysteine-substituted mutants revealed that YycGex possessed dimeric interfaces not only in the loop but also in the helix α1. Cross-linking studies using intact YycG demonstrated that it was capable of forming high molecular weight oligomers on the cell membrane. Furthermore, we also observed that two auxiliary proteins of YycG, YycH and YycI, cooperatively interfered with the multimerization of YycG. From these results, we propose that signaling through YycG is regulated by multimerization and binding of YycH and YycI. These structural studies, combined with biochemical analyses, provide a better understanding of the signaling mechanism of YycG, which is necessary for developing novel antibacterial drugs targeting S. aureus.
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Affiliation(s)
- Truc Kim
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Republic of Korea
| | - Jongkeun Choi
- Department of Cosmetic Science, Chungwoon University, San 29, Namjang, Hongsung, Chungnam 350-701, Republic of Korea
| | - Sangho Lee
- Departments of Biological Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Kwon Joo Yeo
- Division of Magnetic Resonance, Korea Basic Science Institute (KBSI), 162 Yeongudanji-Ro, Ochang, Chungbuk 363-883, Republic of Korea
| | - Hae-Kap Cheong
- Division of Magnetic Resonance, Korea Basic Science Institute (KBSI), 162 Yeongudanji-Ro, Ochang, Chungbuk 363-883, Republic of Korea
| | - Kyeong Kyu Kim
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Republic of Korea.
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146
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Draft Genome Sequences of Vancomycin-Intermediate Staphylococcus aureus Strains in South Korea. GENOME ANNOUNCEMENTS 2016; 4:4/3/e00027-16. [PMID: 27313284 PMCID: PMC4911463 DOI: 10.1128/genomea.00027-16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report here the draft genome sequences of four vancomycin-intermediate Staphylococcus aureus (VISA) strains from South Korean hospitals participating in a nationwide laboratory surveillance program for vancomycin-intermediate and vancomycin-resistant Staphylococcus aureus. All strains harbor mutations in the walKR, graSR, and/or rpoB genes that are known frequently mutated determinants of VISA.
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147
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Genomic Signatures of Experimental Adaptation to Antimicrobial Peptides in Staphylococcus aureus. G3-GENES GENOMES GENETICS 2016; 6:1535-9. [PMID: 27172179 PMCID: PMC4889650 DOI: 10.1534/g3.115.023622] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The evolution of resistance against antimicrobial peptides has long been considered unlikely due to their mechanism of action, yet experimental selection with antimicrobial peptides (AMPs) results in rapid evolution of resistance in several species of bacteria. Although numerous studies have utilized mutant screens to identify loci that determine AMP susceptibility, there is a dearth of data concerning the genomic changes that accompany experimental evolution of AMP resistance. Using genome resequencing, we analyzed the mutations that arose during experimental evolution of resistance to the cationic AMPs iseganan, melittin, and pexiganan, as well as to a combination of melittin and pexiganan, or to the aminoglycoside antibiotic streptomycin. Analysis of 17 independently replicated Staphylococcus aureus selection lines, including unselected controls, showed that each AMP selected for mutations at distinct loci. We identify mutations in genes involved in the synthesis and maintenance of the cell envelope. These include genes previously identified from mutant screens for AMP resistance, and genes involved in the response to AMPs and cell-wall-active antibiotics. Furthermore, transposon insertion mutants were used to verify that a number of the identified genes are directly involved in determining AMP susceptibility. Strains selected for AMP resistance under controlled experimental evolution displayed consistent AMP-specific mutations in genes that determine AMP susceptibility. This suggests that different routes to evolve resistance are favored within a controlled genetic background.
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148
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Poupel O, Moyat M, Groizeleau J, Antunes LCS, Gribaldo S, Msadek T, Dubrac S. Transcriptional Analysis and Subcellular Protein Localization Reveal Specific Features of the Essential WalKR System in Staphylococcus aureus. PLoS One 2016; 11:e0151449. [PMID: 26999783 PMCID: PMC4801191 DOI: 10.1371/journal.pone.0151449] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 02/29/2016] [Indexed: 11/21/2022] Open
Abstract
The WalKR two-component system, controlling cell wall metabolism, is highly conserved among Bacilli and essential for cell viability. In Staphylococcus aureus, walR and walK are followed by three genes of unknown function: walH, walI and walJ. Sequence analysis and transcript mapping revealed a unique genetic structure for this locus in S. aureus: the last gene of the locus, walJ, is transcribed independently, whereas transcription of the tetra-cistronic walRKHI operon occurred from two independent promoters located upstream from walR. Protein topology analysis and protein-protein interactions in E. coli as well as subcellular localization in S. aureus allowed us to show that WalH and WalI are membrane-bound proteins, which associate with WalK to form a complex at the cell division septum. While these interactions suggest that WalH and WalI play a role in activity of the WalKR regulatory pathway, deletion of walH and/or walI did not have a major effect on genes whose expression is strongly dependent on WalKR or on associated phenotypes. No effect of WalH or WalI was seen on tightly controlled WalKR regulon genes such as sle1 or saouhsc_00773, which encodes a CHAP-domain amidase. Of the genes encoding the two major S. aureus autolysins, AtlA and Sle1, only transcription of atlA was increased in the ΔwalH or ΔwalI mutants. Likewise, bacterial autolysis was not increased in the absence of WalH and/or WalI and biofilm formation was lowered rather than increased. Our results suggest that contrary to their major role as WalK inhibitors in B. subtilis, the WalH and WalI proteins have evolved a different function in S. aureus, where they are more accessory. A phylogenomic analysis shows a striking conservation of the 5 gene wal cluster along the evolutionary history of Bacilli, supporting the key importance of this signal transduction system, and indicating that the walH and walI genes were lost in the ancestor of Streptococcaceae, leading to their atypical 3 wal gene cluster, walRKJ.
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Affiliation(s)
- Olivier Poupel
- Institut Pasteur, Biology of Gram-Positive Pathogens, Department of Microbiology, Paris, France
- CNRS, ERL3526, Paris, France
| | - Mati Moyat
- Institut Pasteur, Biology of Gram-Positive Pathogens, Department of Microbiology, Paris, France
- CNRS, ERL3526, Paris, France
| | - Julie Groizeleau
- Institut Pasteur, Biology of Gram-Positive Pathogens, Department of Microbiology, Paris, France
- CNRS, ERL3526, Paris, France
| | - Luísa C. S. Antunes
- Institut Pasteur, Molecular Biology of Gene in Extremophiles, Department of Microbiology, Paris, France
| | - Simonetta Gribaldo
- Institut Pasteur, Molecular Biology of Gene in Extremophiles, Department of Microbiology, Paris, France
| | - Tarek Msadek
- Institut Pasteur, Biology of Gram-Positive Pathogens, Department of Microbiology, Paris, France
- CNRS, ERL3526, Paris, France
- * E-mail: (TM); (SD)
| | - Sarah Dubrac
- Institut Pasteur, Biology of Gram-Positive Pathogens, Department of Microbiology, Paris, France
- CNRS, ERL3526, Paris, France
- * E-mail: (TM); (SD)
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149
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Yousuf FA, Rafiq S, Siddiqui R, Khan NA. The role of genomic islands in Escherichia coli K1 interactions with intestinal and kidney epithelial cells. Microb Pathog 2016; 93:145-51. [PMID: 26867478 DOI: 10.1016/j.micpath.2016.02.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 02/01/2016] [Accepted: 02/01/2016] [Indexed: 10/22/2022]
Abstract
The completion of Escherichia coli K1 genome has identified several genomic islands that are present in meningitis-causing E. coli RS218 but absent in the non-pathogenic E. coli MG1655. In this study, the role of various genomic islands in E. coli K1 interactions with intestinal epithelial cells (Caco-2) and kidney epithelial cells (MA104) was determined. Using association assays, invasion assays, and intracellular survival assays, the findings revealed that the genomic island deletion mutants of RS218 related to P fimbriae, S fimbriae, F17-like fimbriae, non-fimbrial adhesins, Hek and hemagglutinin, protein secretion system (T1SS for hemolysin; T2SS; T5SS for antigen 43), Iro system and hmu system), invasins (CNF1, IbeA), toxins (α-hemolysin), K1 capsule biosynthesis, metabolism (d-serine catabolism, dihydroxyacetone, glycerol, and glyoxylate metabolism), prophage genes, showed reduced interactions with both cell types. Next, we determined the role of various genomic islands in E. coli K1 resistance to serum. When exposed to the normal human serum, the viability of the genomic island deletion mutants related to adhesins such as S fimbriae, P fimbriae, F17-like fimbriae, non-fimbrial adhesins, Hek and hemagglutinin, antigen 43 and T5SS for antigen 43, T2SS, and T1SS for hemolysin, Iro system and hmu system, prophage genes, metabolism (sugar metabolism and d-serine catabolism), K1 capsule biosynthesis, and invasins such as CNF1 was affected, suggesting their role in bacteremia. The characterization of these genomic islands should reveal mechanisms of E. coli K1 pathogenicity that could be of value as therapeutic targets.
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Affiliation(s)
| | - Sahar Rafiq
- Department of Biological and Biomedical Sciences, Aga Khan University, Pakistan
| | - Ruqaiyyah Siddiqui
- Department of Biological Sciences, Faculty of Science and Technology, Sunway University, Malaysia
| | - Naveed Ahmed Khan
- Department of Biological Sciences, Faculty of Science and Technology, Sunway University, Malaysia.
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150
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Hewelt-Belka W, Nakonieczna J, Belka M, Bączek T, Namieśnik J, Kot-Wasik A. Untargeted Lipidomics Reveals Differences in the Lipid Pattern among Clinical Isolates of Staphylococcus aureus Resistant and Sensitive to Antibiotics. J Proteome Res 2016; 15:914-22. [DOI: 10.1021/acs.jproteome.5b00915] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Weronika Hewelt-Belka
- Department
of Analytical Chemistry, Faculty of Chemistry, Gdańsk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Joanna Nakonieczna
- Department
of Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Kładki
24, 80-822 Gdańsk, Poland
| | - Mariusz Belka
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, Medical University of Gdańsk, Al. Gen. J. Hallera 107, 80-416 Gdańsk, Poland
| | - Tomasz Bączek
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, Medical University of Gdańsk, Al. Gen. J. Hallera 107, 80-416 Gdańsk, Poland
| | - Jacek Namieśnik
- Department
of Analytical Chemistry, Faculty of Chemistry, Gdańsk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Agata Kot-Wasik
- Department
of Analytical Chemistry, Faculty of Chemistry, Gdańsk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdańsk, Poland
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