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Ravi J, Anantharaman V, Chen SZ, Brenner EP, Datta P, Aravind L, Gennaro ML. The phage shock protein (PSP) envelope stress response: discovery of novel partners and evolutionary history. mSystems 2024; 9:e0084723. [PMID: 38809013 PMCID: PMC11237479 DOI: 10.1128/msystems.00847-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 03/20/2024] [Indexed: 05/30/2024] Open
Abstract
Bacterial phage shock protein (PSP) systems stabilize the bacterial cell membrane and protect against envelope stress. These systems have been associated with virulence, but despite their critical roles, PSP components are not well characterized outside proteobacteria. Using comparative genomics and protein sequence-structure-function analyses, we systematically identified and analyzed PSP homologs, phyletic patterns, domain architectures, and gene neighborhoods. This approach underscored the evolutionary significance of the system, revealing that its core protein PspA (Snf7 in ESCRT outside bacteria) was present in the last universal common ancestor and that this ancestral functionality has since diversified into multiple novel, distinct PSP systems across life. Several novel partners of the PSP system were identified: (i) the Toastrack domain, likely facilitating assembly of sub-membrane stress-sensing and signaling complexes, (ii) the newly defined HTH-associated α-helical signaling domain-PadR-like transcriptional regulator pair system, and (iii) multiple independent associations with ATPase, CesT/Tir-like chaperone, and Band-7 domains in proteins thought to mediate sub-membrane dynamics. Our work also uncovered links between the PSP components and other domains, such as novel variants of SHOCT-like domains, suggesting roles in assembling membrane-associated complexes of proteins with disparate biochemical functions. Results are available at our interactive web app, https://jravilab.org/psp.IMPORTANCEPhage shock proteins (PSP) are virulence-associated, cell membrane stress-protective systems. They have mostly been characterized in Proteobacteria and Firmicutes. We now show that a minimal PSP system was present in the last universal common ancestor that evolved and diversified into newly identified functional contexts. Recognizing the conservation and evolution of PSP systems across bacterial phyla contributes to our understanding of stress response mechanisms in prokaryotes. Moreover, the newly discovered PSP modularity will likely prompt new studies of lineage-specific cell envelope structures, lifestyles, and adaptation mechanisms. Finally, our results validate the use of domain architecture and genetic context for discovery in comparative genomics.
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Affiliation(s)
- Janani Ravi
- Department of Biomedical Informatics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Public Health Research Institute, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Vivek Anantharaman
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, Maryland, USA
| | - Samuel Zorn Chen
- Computer Science Engineering Undergraduate Program, Michigan State University, East Lansing, Michigan, USA
| | - Evan Pierce Brenner
- Department of Biomedical Informatics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Pratik Datta
- Public Health Research Institute, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - L. Aravind
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, Maryland, USA
| | - Maria Laura Gennaro
- Public Health Research Institute, Rutgers New Jersey Medical School, Newark, New Jersey, USA
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Morris SM, Wiens L, Rose O, Fritz G, Rogers T, Gebhard S. Regulatory interactions between daptomycin- and bacitracin-responsive pathways coordinate the cell envelope antibiotic resistance response of Enterococcus faecalis. Mol Microbiol 2024; 121:1148-1163. [PMID: 38646792 DOI: 10.1111/mmi.15264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 04/02/2024] [Accepted: 04/03/2024] [Indexed: 04/23/2024]
Abstract
Enterococcal infections frequently show high levels of antibiotic resistance, including to cell envelope-acting antibiotics like daptomycin (DAP). While we have a good understanding of the resistance mechanisms, less is known about the control of such resistance genes in enterococci. Previous work unveiled a bacitracin resistance network, comprised of the sensory ABC transporter SapAB, the two-component system (TCS) SapRS and the resistance ABC transporter RapAB. Interestingly, components of this system have recently been implicated in DAP resistance, a role usually regulated by the TCS LiaFSR. To better understand the regulation of DAP resistance and how this relates to mutations observed in DAP-resistant clinical isolates of enterococci, we here explored the interplay between these two regulatory pathways. Our results show that SapR regulates an additional resistance operon, dltXABCD, a known DAP resistance determinant, and show that LiaFSR regulates the expression of sapRS. This regulatory structure places SapRS-target genes under dual control, where expression is directly controlled by SapRS, which itself is up-regulated through LiaFSR. The network structure described here shows how Enterococcus faecalis coordinates its response to cell envelope attack and can explain why clinical DAP resistance often emerges via mutations in regulatory components.
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Affiliation(s)
- Sali M Morris
- Life Sciences Department, Milner Centre for Evolution, University of Bath, Bath, UK
| | - Laura Wiens
- Institute of Molecular Physiology, Johannes-Gutenberg-University Mainz, Mainz, Germany
| | - Olivia Rose
- Life Sciences Department, Milner Centre for Evolution, University of Bath, Bath, UK
| | - Georg Fritz
- School of Molecular Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Tim Rogers
- Department of Mathematical Sciences, University of Bath, Bath, UK
| | - Susanne Gebhard
- Life Sciences Department, Milner Centre for Evolution, University of Bath, Bath, UK
- Institute of Molecular Physiology, Johannes-Gutenberg-University Mainz, Mainz, Germany
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3
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Nair ZJ, Gao IH, Firras A, Chong KKL, Hill ED, Choo PY, Colomer-Winter C, Chen Q, Manzano C, Pethe K, Kline KA. An essential protease, FtsH, influences daptomycin resistance acquisition in Enterococcus faecalis. Mol Microbiol 2024; 121:1021-1038. [PMID: 38527904 DOI: 10.1111/mmi.15253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 03/11/2024] [Accepted: 03/11/2024] [Indexed: 03/27/2024]
Abstract
Daptomycin is a last-line antibiotic commonly used to treat vancomycin-resistant Enterococci, but resistance evolves rapidly and further restricts already limited treatment options. While genetic determinants associated with clinical daptomycin resistance (DAPR) have been described, information on factors affecting the speed of DAPR acquisition is limited. The multiple peptide resistance factor (MprF), a phosphatidylglycerol-modifying enzyme involved in cationic antimicrobial resistance, is linked to DAPR in pathogens such as methicillin-resistant Staphylococcus aureus. Since Enterococcus faecalis encodes two paralogs of mprF and clinical DAPR mutations do not map to mprF, we hypothesized that functional redundancy between the paralogs prevents mprF-mediated resistance and masks other evolutionary pathways to DAPR. Here, we performed in vitro evolution to DAPR in mprF mutant background. We discovered that the absence of mprF results in slowed DAPR evolution and is associated with inactivating mutations in ftsH, resulting in the depletion of the chaperone repressor HrcA. We also report that ftsH is essential in the parental, but not in the ΔmprF, strain where FtsH depletion results in growth impairment in the parental strain, a phenotype associated with reduced extracellular acidification and reduced ability for metabolic reduction. This presents FtsH and HrcA as enticing targets for developing anti-resistance strategies.
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Affiliation(s)
- Zeus Jaren Nair
- Singapore-MIT Alliance for Research and Technology, Antimicrobial Drug Resistance Interdisciplinary Research Group, Singapore, Singapore
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- Interdisciplinary Graduate Programme, Graduate College, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Iris Hanxing Gao
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Aslam Firras
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Kelvin Kian Long Chong
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- Interdisciplinary Graduate Programme, Graduate College, Nanyang Technological University, Singapore, Singapore
| | - Eric D Hill
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore, Singapore
| | - Pei Yi Choo
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Cristina Colomer-Winter
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Qingyan Chen
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Caroline Manzano
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Kevin Pethe
- Singapore-MIT Alliance for Research and Technology, Antimicrobial Drug Resistance Interdisciplinary Research Group, Singapore, Singapore
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- National Centre for Infectious Diseases (NCID), Singapore, Singapore
| | - Kimberly A Kline
- Singapore-MIT Alliance for Research and Technology, Antimicrobial Drug Resistance Interdisciplinary Research Group, Singapore, Singapore
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
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Zbylicki BR, Murphy CE, Petsche JA, Müh U, Dobrila HA, Ho TD, Daum MN, Pannullo AG, Weiss DS, Ellermeier CD. Identification of Clostridioides difficile mutants with increased daptomycin resistance. J Bacteriol 2024; 206:e0036823. [PMID: 38376203 PMCID: PMC10955854 DOI: 10.1128/jb.00368-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 01/20/2024] [Indexed: 02/21/2024] Open
Abstract
Daptomycin is a cyclic lipopeptide antibiotic used to treat infections caused by some Gram-positive bacteria. Daptomycin disrupts synthesis of the peptidoglycan (PG) cell wall by inserting into the cytoplasmic membrane and binding multiple forms of the undecaprenyl carrier lipid required for PG synthesis. Membrane insertion requires phosphatidylglycerol, so studies of daptomycin can provide insight into assembly and maintenance of the cytoplasmic membrane. Here, we studied the effects of daptomycin on Clostridioides difficile, the leading cause of healthcare-associated diarrhea. We observed that growth of C. difficile strain R20291 in the presence of sub-MIC levels of daptomycin resulted in a chaining phenotype, minicell formation, and lysis-phenotypes broadly consistent with perturbation of membranes and PG synthesis. We also selected for and characterized eight mutants with elevated daptomycin resistance. The mutations in these mutants were mapped to four genes: cdsA (cdr20291_2041), ftsH2 (cdr20291_3396), esrR (cdr20291_1187), and draS (cdr20291_2456). Of these four genes, only draS has been characterized previously. Follow-up studies indicate these mutations confer daptomycin resistance by two general mechanisms: reducing the amount of phosphatidylglycerol in the cytoplasmic membrane (cdsA) or altering the regulation of membrane processes (ftsH2, esrR, and draS). Thus, the mutants described here provide insights into phospholipid synthesis and identify signal transduction systems involved in cell envelope biogenesis and stress response in C. difficile. IMPORTANCE C. difficile is the leading cause of healthcare-associated diarrhea and is a threat to public health due to the risk of recurrent infections. Understanding biosynthesis of the atypical cell envelope of C. difficile may provide insight into novel drug targets to selectively inhibit C. difficile. Here, we identified mutations that increased daptomycin resistance and allowed us to better understand phospholipid synthesis, cell envelope biogenesis, and stress response in C. difficile.
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Affiliation(s)
- Brianne R. Zbylicki
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, USA
| | - Claire E. Murphy
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, USA
| | - Jennifer A. Petsche
- Interdisciplinary Graduate Program in Molecular Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Ute Müh
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, USA
| | - Horia A. Dobrila
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, USA
| | - Theresa D. Ho
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, USA
| | - Mikaela N. Daum
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, USA
| | - Anthony G. Pannullo
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, USA
| | - David S. Weiss
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, USA
| | - Craig D. Ellermeier
- Department of Microbiology and Immunology, The University of Iowa, Iowa City, Iowa, USA
- Graduate Program in Genetics, University of Iowa, Iowa City, Iowa, USA
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Dumitrascu F, Caira MR, Avram S, Buiu C, Udrea AM, Vlad IM, Zarafu I, Ioniță P, Nuță DC, Popa M, Chifiriuc MC, Limban C. Repurposing anti-inflammatory drugs for fighting planktonic and biofilm growth. New carbazole derivatives based on the NSAID carprofen: synthesis, in silico and in vitro bioevaluation. Front Cell Infect Microbiol 2023; 13:1181516. [PMID: 37680749 PMCID: PMC10482414 DOI: 10.3389/fcimb.2023.1181516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 06/14/2023] [Indexed: 09/09/2023] Open
Abstract
Introduction One of the promising leads for the rapid discovery of alternative antimicrobial agents is to repurpose other drugs, such as nonsteroidal anti-inflammatory agents (NSAIDs) for fighting bacterial infections and antimicrobial resistance. Methods A series of new carbazole derivatives based on the readily available anti-inflammatory drug carprofen has been obtained by nitration, halogenation and N-alkylation of carprofen and its esters. The structures of these carbazole compounds were assigned by NMR and IR spectroscopy. Regioselective electrophilic substitution by nitration and halogenation at the carbazole ring was assigned from H NMR spectra. The single crystal X-ray structures of two representative derivatives obtained by dibromination of carprofen, were also determined. The total antioxidant capacity (TAC) was measured using the DPPH method. The antimicrobial activity assay was performed using quantitative methods, allowing establishment of the minimal inhibitory/bactericidal/biofilm eradication concentrations (MIC/MBC/MBEC) on Gram-positive (Staphylococcus aureus, Enterococcus faecalis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) strains. Computational assays have been performed to assess the drug- and lead-likeness, pharmacokinetics (ADME-Tox) and pharmacogenomics profiles. Results and discussion The crystal X-ray structures of 3,8-dibromocarprofen and its methyl ester have revealed significant differences in their supramolecular assemblies. The most active antioxidant compound was 1i, bearing one chlorine and two bromine atoms, as well as the CO2Me group. Among the tested derivatives, 1h bearing one chlorine and two bromine atoms has exhibited the widest antibacterial spectrum and the most intensive inhibitory activity, especially against the Gram-positive strains, in planktonic and biofilm growth state. The compounds 1a (bearing one chlorine, one NO2 and one CO2Me group) and 1i (bearing one chlorine, two bromine atoms and a CO2Me group) exhibited the best antibiofilm activity in the case of the P. aeruginosa strain. Moreover, these compounds comply with the drug-likeness rules, have good oral bioavailability and are not carcinogenic or mutagenic. The results demonstrate that these new carbazole derivatives have a molecular profile which deserves to be explored further for the development of novel antibacterial and antibiofilm agents.
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Affiliation(s)
- Florea Dumitrascu
- ”C. D. Nenitzescu” Institute of Organic and Supramolecular Chemistry, Center for Organic Chemistry, Bucharest, Romania
| | - Mino R. Caira
- Department of Chemistry, University of Cape Town, Cape Town, South Africa
| | - Speranta Avram
- Department of Anatomy, Animal Physiology, and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Catalin Buiu
- Department of Automatic Control and Systems Engineering, Politehnica University of Bucharest, Bucharest, Romania
| | - Ana Maria Udrea
- Laser Department, National Institute for Laser, Plasma and Radiation Physics, Magurele, Romania
- Research Institute of the University of Bucharest—ICUB, University of Bucharest, Bucharest, Romania
| | - Ilinca Margareta Vlad
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania
| | - Irina Zarafu
- Department of Organic Chemistry, Biochemistry and Catalysis, Faculty of Chemistry, University of Bucharest, Bucharest, Romania
| | - Petre Ioniță
- Department of Organic Chemistry, Biochemistry and Catalysis, Faculty of Chemistry, University of Bucharest, Bucharest, Romania
| | - Diana Camelia Nuță
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania
| | - Marcela Popa
- Research Institute of the University of Bucharest—ICUB, University of Bucharest, Bucharest, Romania
| | - Mariana-Carmen Chifiriuc
- Research Institute of the University of Bucharest—ICUB, University of Bucharest, Bucharest, Romania
- Department of Botany and Microbiology, University of Bucharest, Bucharest, Romania
- Biological Sciences Section, Romanian Academy, Bucharest, Romania
| | - Carmen Limban
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania
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Nguyen AH, Tran TT, Panesso D, Hood K, Polamraju V, Zhang R, Khan A, Miller WR, Mileykovskaya E, Shamoo Y, Xu L, Vitrac H, Arias CA. Molecular Basis of Cell Membrane Adaptation in Daptomycin-Resistant Enterococcus faecalis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.02.551704. [PMID: 37577577 PMCID: PMC10418189 DOI: 10.1101/2023.08.02.551704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Daptomycin is a last-resort lipopeptide antibiotic that disrupts cell membrane (CM) and peptidoglycan homeostasis. Enterococcus faecalis has developed a sophisticated mechanism to avoid daptomycin killing by re-distributing CM anionic phospholipids away from the septum. The CM changes are orchestrated by a three-component regulatory system, designated LiaFSR, with a possible contribution of cardiolipin synthase (Cls). However, the mechanism by which LiaFSR controls the CM response and the role of Cls are unknown. Here, we show that cardiolipin synthase activity is essential for anionic phospholipid redistribution and daptomycin resistance since deletion of the two genes ( cls1 and cls2 ) encoding Cls abolished CM remodeling. We identified LiaY, a transmembrane protein regulated by LiaFSR, as an important mediator of CM remodeling required for re-distribution of anionic phospholipid microdomains via interactions with Cls1. Together, our insights provide a mechanistic framework on the enterococcal response to cell envelope antibiotics that could be exploited therapeutically.
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7
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Rimal B, Chang J, Liu C, Rashid R, Singh M, Kim SJ. The effects of daptomycin on cell wall biosynthesis in Enterococcal faecalis. Sci Rep 2023; 13:12227. [PMID: 37507537 PMCID: PMC10382475 DOI: 10.1038/s41598-023-39486-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Accepted: 07/26/2023] [Indexed: 07/30/2023] Open
Abstract
Daptomycin is a cyclic lipodepsipeptide antibiotic reserved for the treatment of serious infections by multidrug-resistant Gram-positive pathogens. Its mode of action is considered to be multifaceted, encompassing the targeting and depolarization of bacterial cell membranes, alongside the inhibition of cell wall biosynthesis. To characterize the daptomycin mode of action, 15N cross-polarization at magic-angle spinning NMR measurements were performed on intact whole cells of Staphylococcus aureus grown in the presence of a sub-inhibitory concentration of daptomycin in a chemically defined media containing L-[ϵ-15N]Lys. Daptomycin-treated cells showed a reduction in the lysyl-ε-amide intensity that was consistent with cell wall thinning. However, the reduced lysyl-ε-amine intensity at 10 ppm indicated that the daptomycin-treated cells did not accumulate in Park's nucleotide, the cytoplasmic peptidoglycan (PG) precursor. Consequently, daptomycin did not inhibit the transglycosylation step of PG biosynthesis. To further elucidate the daptomycin mode of action, the PG composition of daptomycin-susceptible Enterococcus faecalis grown in the presence of daptomycin was analyzed using liquid chromatography-mass spectrometry. Sixty-nine muropeptide ions correspond to PG with varying degrees of modifications including crosslinking, acetylation, alanylation, and 1,6-anhydrous ring formation at MurNAc were quantified. Analysis showed that the cell walls of daptomycin-treated E. faecalis had a significant reduction in PG crosslinking which was accompanied by an increase in lytic transglycosylase activities and a decrease in PG-stem modifications by the carboxypeptidases. The changes in PG composition suggest that daptomycin inhibits cell wall biosynthesis by impeding the incorporation of nascent PG into the cell walls by transpeptidases and maturation by carboxypeptidases. As a result, the newly formed cell walls become highly susceptible to degradation by the autolysins, resulting in thinning of the cell wall.
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Affiliation(s)
- Binayak Rimal
- Institute of Biomedical Studies, Baylor University, Waco, TX, 76798, USA
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - James Chang
- Department of Chemistry One Bear Place #97046, Baylor University, Waco, TX, 76798, USA
| | - Chengyin Liu
- Department of Chemistry, Howard University, Washington, DC, 20059, USA
| | - Raiyan Rashid
- Department of Chemistry, Howard University, Washington, DC, 20059, USA
| | - Manmilan Singh
- Department of Chemistry, Washington University, St. Louis, MO, 63110, USA
| | - Sung Joon Kim
- Department of Chemistry, Howard University, Washington, DC, 20059, USA.
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Fitzgerald BA, Wadud A, Slimak Z, Slonczewski JL. Enterococcus faecalis OG1RF Evolution at Low pH Selects Fusidate-Sensitive Mutants in Elongation Factor G and at High pH Selects Defects in Phosphate Transport. Appl Environ Microbiol 2023; 89:e0046623. [PMID: 37272807 PMCID: PMC10304957 DOI: 10.1128/aem.00466-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 05/15/2023] [Indexed: 06/06/2023] Open
Abstract
Enterococcus bacteria inhabit human and soil environments that show a wide range of pH values. Strains include commensals as well as antibiotic-resistant pathogens. We investigated the adaptation to pH stress in E. faecalis OG1RF by conducting experimental evolution under acidic (pH 4.8), neutral pH (pH 7.0), and basic (pH 9.0) conditions. A serial planktonic culture was performed for 500 generations and in a high-pH biofilm culture for 4 serial bead transfers. Nearly all of the mutations led to nonsynonomous codons, indicating adaptive selection. All of the acid-adapted clones from the planktonic culture showed a mutation in fusA (encoding elongation factor G). The acid-adapted fusA mutants had a trade-off of decreased resistance to fusidic acid (fusidate). All of the base-adapted clones from the planktonic cultures as well as some from the biofilm-adapted cultures showed mutations that affected the Pst phosphate ABC transporter (pstA, pstB, pstB2, pstC) and pyrR (pyrimidine biosynthesis regulator/uracil phosphoribosyltransferase). The biofilm cultures produced small-size colonies on brain heart infusion agar. These variants each contained a single mutation in pstB2, pstC, or pyrR. The pst and pyrR mutants outgrew the ancestral strain at pH 9.2, with a trade-off of lower growth at pH 4.8. Additional genes that had a mutation in multiple clones that evolved at high pH (but not at low pH) include opp1BCDF (oligopeptide ABC transporter), ccpA (catabolite control protein A), and ftsZ (septation protein). Overall, the experimental evolution of E. faecalis showed a strong pH dependence, favoring the fusidate-sensitive elongation factor G modification at low pH and the loss of phosphate transport genes at high pH. IMPORTANCE E. faecalis bacteria are found in dental biofilms, where they experience low pH as a result of fermentative metabolism. Thus, the effect of pH on antibiotic resistance has clinical importance. The loss of fusidate resistance is notable for OG1RF strains in which fusidate resistance is assumed to be a stable genetic marker. In endodontal infections, enterococci can resist calcium hydroxide therapy that generates extremely high pH values. In other environments, such as the soil and plant rhizosphere, enterococci experience acidification that is associated with climate change. Thus, the pH modulation of natural selection in enterococci is important for human health as well as for understanding soil environments.
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Affiliation(s)
| | - Ayman Wadud
- Department of Biology, Kenyon College, Gambier, Ohio, USA
| | - Zachary Slimak
- Department of Biology, Kenyon College, Gambier, Ohio, USA
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Tymoszewska A, Szylińska M, Aleksandrzak-Piekarczyk T. The LiaFSR-LiaX System Mediates Resistance of Enterococcus faecium to Peptide Antibiotics and to Aureocin A53- and Enterocin L50-Like Bacteriocins. Microbiol Spectr 2023; 11:e0034323. [PMID: 37219451 PMCID: PMC10269926 DOI: 10.1128/spectrum.00343-23] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 05/07/2023] [Indexed: 05/24/2023] Open
Abstract
Multidrug-resistant Enterococcus faecium strains are currently a leading cause of difficult-to-treat nosocomial infections. The emerging resistance of enterococci to last-resort antibiotics, such as daptomycin, prompts a search for alternative antimicrobials. Aureocin A53- and enterocin L50-like bacteriocins are potent antimicrobial agents that form daptomycin-like cationic complexes and have a similar cell envelope-targeting mechanism of action, suggesting their potential as next-generation antibiotics. However, to ensure their safe use, the mechanisms of resistance to these bacteriocins and cross-resistance to antibiotics need to be well understood. Here, we investigated the genetic basis of E. faecium's resistance to aureocin A53- and enterocin L50-like bacteriocins and compared it with that to antibiotics. First, we selected spontaneous mutants resistant to the bacteriocin BHT-B and identified adaptive mutations in the liaFSR-liaX genes encoding the LiaFSR stress response regulatory system and the daptomycin-sensing protein LiaX, respectively. We then demonstrated that a gain-of-function mutation in liaR increases the expression of liaFSR, liaXYZ, cell wall remodeling-associated genes, and hypothetical genes involved in protection against various antimicrobials. Finally, we showed that adaptive mutations or overexpression of liaSR or liaR alone results in cross-resistance to other aureocin A53- and enterocin L50-like bacteriocins, as well as antibiotics targeting specific components of the cell envelope (daptomycin, ramoplanin, gramicidin) or ribosomes (kanamycin and gentamicin). Based on the obtained results, we concluded that activation of the LiaFSR-mediated stress response confers resistance to peptide antibiotics and bacteriocins via a cascade of reactions, eventually leading to cell envelope remodeling. IMPORTANCE Pathogenic enterococci carry virulence factors and a considerable resistome, which makes them one of the most serious and steadily increasing causes of hospital epidemiological risks. Accordingly, Enterococcus faecium is classified into a top-priority ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) group of six highly virulent and multidrug-resistant (MDR) bacterial pathogens for which novel antimicrobial agents need to be developed urgently. Alternative measures, such as the use of bacteriocins, separately or in combination with other antimicrobial agents (e.g., antibiotics), could be a potential solution, especially since several international health agencies recommend and support the development of such interventions. Nevertheless, in order to exploit their efficacy, more basic research on the mechanisms of cell killing and the development of resistance to bacteriocins is needed. The present study fills some of the knowledge gaps regarding the genetic basis of the development of resistance to potent antienterococcal bacteriocins, pointing out the common and divergent features regarding the cross-resistance to antibiotics.
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Affiliation(s)
- Aleksandra Tymoszewska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences (IBB PAS), Warsaw, Poland
| | - Marlena Szylińska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences (IBB PAS), Warsaw, Poland
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10
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Rao Tatta E, Paul S, Kumavath R. Transcriptome Analysis revealed the Synergism of Novel Rhodethrin inhibition on Biofilm architecture, Antibiotic Resistance and Quorum sensing inEnterococcus faecalis. Gene 2023; 871:147436. [PMID: 37075926 DOI: 10.1016/j.gene.2023.147436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/31/2023] [Accepted: 04/13/2023] [Indexed: 04/21/2023]
Abstract
Enterococcus sp. emerged as an opportunistic nosocomial pathogen with the highest antibiotic resistance and mortality rate. Biofilm is problematic primarily since it is regulated by the global bacterial cell to cell communication mediated by the quorum sensing system. sing system. Thus, potential natural antagonists in a novel drug formulation against biofilm-forming Enterococcus faecalis is critical. We used RNA-Seq to evaluate the effects of the novel molecule rhodethrin with chloramphenicol induced on Enterococcus faecalis and DEGs were identified. In transcriptome sequence analysis, a total of 448 with control Vs rhodethrin, 1591 were in control Vs chloramphenicol, 379 genes were DEGs from control Vs synergies, in rhodethrin with chloramphenicol, 379 genes were differentially expressed, whereas 264 genes were significantly downregulated, indicating that 69.69% ofE. faecaliswas altered. The transcriptional sequence data further expression analysis qRT-PCR, and the results shed that the expression profiles of five significant biofilm formation responsible genes such as, Ace, AtpB, lepA, bopD, and typA, 3 genes involved in quorum sensing are sylA, fsrC and camE, and 4 genes involved in resistance were among including liaX, typA, EfrA, and lepA, were significantly suppressed expressions of the biofilm, quorum sensing, and resistance that are supported by transcriptome analysis.
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Affiliation(s)
- Eswar Rao Tatta
- Department of Genomic Science, School of Biological Sciences, Central University of Kerala, Tejaswini Hills, Periya (PO), Kasaragod, Kerala 671320, India
| | - Sayan Paul
- Department of Biochemistry & Molecular Biology, the University of Texas Medical Branch at Galveston, Galveston, Texas 77555, USA
| | - Ranjith Kumavath
- Department of Genomic Science, School of Biological Sciences, Central University of Kerala, Tejaswini Hills, Periya (PO), Kasaragod, Kerala 671320, India; Department of Biotechnology, School of Life Sciences, Pondicherry University, Puducherry 605014, India.
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11
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Usui M, Yoshii Y, Thiriet-Rupert S, Ghigo JM, Beloin C. Intermittent antibiotic treatment of bacterial biofilms favors the rapid evolution of resistance. Commun Biol 2023; 6:275. [PMID: 36928386 PMCID: PMC10020551 DOI: 10.1038/s42003-023-04601-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 02/16/2023] [Indexed: 03/18/2023] Open
Abstract
Bacterial antibiotic resistance is a global health concern of increasing importance and intensive study. Although biofilms are a common source of infections in clinical settings, little is known about the development of antibiotic resistance within biofilms. Here, we use experimental evolution to compare selection of resistance mutations in planktonic and biofilm Escherichia coli populations exposed to clinically relevant cycles of lethal treatment with the aminoglycoside amikacin. Consistently, mutations in sbmA, encoding an inner membrane peptide transporter, and fusA, encoding the essential elongation factor G, are rapidly selected in biofilms, but not in planktonic cells. This is due to a combination of enhanced mutation rate, increased adhesion capacity and protective biofilm-associated tolerance. These results show that the biofilm environment favors rapid evolution of resistance and provide new insights into the dynamic evolution of antibiotic resistance in biofilms.
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Affiliation(s)
- Masaru Usui
- Laboratory of Food Microbiology and Food Safety, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Hokkaido, Japan.
- Institut Pasteur, Université de Paris Cité, UMR CNRS 6047, Genetics of Biofilms Laboratory, 75015, Paris, France.
| | - Yutaka Yoshii
- Institut Pasteur, Université de Paris Cité, UMR CNRS 6047, Genetics of Biofilms Laboratory, 75015, Paris, France
| | - Stanislas Thiriet-Rupert
- Institut Pasteur, Université de Paris Cité, UMR CNRS 6047, Genetics of Biofilms Laboratory, 75015, Paris, France
| | - Jean-Marc Ghigo
- Institut Pasteur, Université de Paris Cité, UMR CNRS 6047, Genetics of Biofilms Laboratory, 75015, Paris, France
| | - Christophe Beloin
- Institut Pasteur, Université de Paris Cité, UMR CNRS 6047, Genetics of Biofilms Laboratory, 75015, Paris, France.
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12
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Zhou Y, Utama B, Pratap S, Supandy A, Song X, Tran TT, Mehta HH, Arias CA, Shamoo Y. Enolpyruvate transferase MurAA A149E, identified during adaptation of Enterococcus faecium to daptomycin, increases stability of MurAA-MurG interaction. J Biol Chem 2023; 299:102912. [PMID: 36649910 PMCID: PMC9975281 DOI: 10.1016/j.jbc.2023.102912] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 01/15/2023] Open
Abstract
Daptomycin (DAP) is an antibiotic frequently used as a drug of last resort against vancomycin-resistant enterococci. One of the major challenges when using DAP against vancomycin-resistant enterococci is the emergence of resistance, which is mediated by the cell-envelope stress system LiaFSR. Indeed, inhibition of LiaFSR signaling has been suggested as a strategy to "resensitize" enterococci to DAP. In the absence of LiaFSR, alternative pathways mediating DAP resistance have been identified, including adaptive mutations in the enolpyruvate transferase MurAA (MurAAA149E), which catalyzes the first committed step in peptidoglycan biosynthesis; however, how these mutations confer resistance is unclear. Here, we investigated the biochemical basis for MurAAA149E-mediated adaptation to DAP to determine whether such an alternative pathway would undermine the potential efficacy of therapies that target the LiaFSR pathway. We found cells expressing MurAAA149E had increased susceptibility to glycoside hydrolases, consistent with decreased cell wall integrity. Furthermore, structure-function studies of MurAA and MurAAA149E using X-ray crystallography and biochemical analyses indicated only a modest decrease in MurAAA149E activity, but a 16-fold increase in affinity for MurG, which performs the last intracellular step of peptidoglycan synthesis. Exposure to DAP leads to mislocalization of cell division proteins including MurG. In Bacillus subtilis, MurAA and MurG colocalize at division septa and, thus, we propose MurAAA149E may contribute to DAP nonsusceptibility by increasing the stability of MurAA-MurG interactions to reduce DAP-induced mislocalization of these essential protein complexes.
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Affiliation(s)
- Yue Zhou
- Department of Biosciences, Rice University, Houston, Texas, USA
| | - Budi Utama
- Shared Equipment Authority, Rice University, Houston, Texas, USA
| | | | - Adeline Supandy
- Department of Biosciences, Rice University, Houston, Texas, USA
| | - Xinhao Song
- Department of Biosciences, Rice University, Houston, Texas, USA
| | - Truc T Tran
- Center for Infectious Diseases Research, Houston Methodist Research Institute, Houston, Texas, USA
| | - Heer H Mehta
- Department of Biosciences, Rice University, Houston, Texas, USA
| | - Cesar A Arias
- Center for Infectious Diseases Research, Houston Methodist Research Institute, Houston, Texas, USA; Division of Infectious Diseases, Houston Methodist Hospital, Houston, Texas, USA
| | - Yousif Shamoo
- Department of Biosciences, Rice University, Houston, Texas, USA.
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13
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Mehta HH, Song X, Shamoo Y. Intracellular Experimental Evolution of Francisella tularensis Subsp. holarctica Live Vaccine Strain (LVS) to Antimicrobial Resistance. ACS Infect Dis 2023; 9:308-321. [PMID: 36662533 PMCID: PMC9996545 DOI: 10.1021/acsinfecdis.2c00483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In vitro experimental evolution has complemented clinical studies as an excellent tool to identify genetic changes responsible for the de novo evolution of antimicrobial resistance. However, the in vivo context for adaptation contributes to the success of particular evolutionary trajectories, especially in intracellular niches where the adaptive landscape of virulence and resistance are strongly coupled. In this work, we designed an ex vivo evolution approach to identify evolutionary trajectories responsible for antibiotic resistance in the Live Vaccine Strain (LVS) of Francisella tularensis subsp. holarctica while being passaged to increasing ciprofloxacin (CIP) and doxycycline (DOX) concentrations within macrophages. Overall, adaptation within macrophages advanced much slower when compared to previous in vitro evolution studies reflecting a limiting capacity for the expansion of adaptive mutations within the macrophage. Longitudinal genomic analysis identified resistance conferring gyrase mutations outside the Quinolone Resistance Determining Region. Strikingly, FupA/B mutations that are uniquely associated with in vitro CIP resistance in Francisella were not observed ex vivo, reflecting the coupling of intracellular survival and resistance during intracellular adaptation. To our knowledge, this is the first experimental study demonstrating the ability to conduct experimental evolution to antimicrobial resistance within macrophages. The results provide evidence of differences in mutational profiles of populations adapted to the same antibiotic in different environments/cellular compartments and underscore the significance of host mediated stress during resistance evolution.
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Affiliation(s)
- Heer H Mehta
- Department of BioSciences, Rice University, Houston, Texas 77005, United States
| | - Xinhao Song
- Department of BioSciences, Rice University, Houston, Texas 77005, United States
| | - Yousif Shamoo
- Department of BioSciences, Rice University, Houston, Texas 77005, United States
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14
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Nguyen AH, Hood KS, Mileykovskaya E, Miller WR, Tran TT. Bacterial cell membranes and their role in daptomycin resistance: A review. Front Mol Biosci 2022; 9:1035574. [PMID: 36452455 PMCID: PMC9702088 DOI: 10.3389/fmolb.2022.1035574] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 10/26/2022] [Indexed: 11/16/2022] Open
Abstract
Lipids play a major role in bacterial cells. Foremost, lipids are the primary constituents of the cell membrane bilayer, providing structure and separating the cell from the surrounding environment. This makes the lipid bilayer a prime target for antimicrobial peptides and membrane-acting antibiotics such as daptomycin. In response, bacteria have evolved mechanisms by which the membrane can be adapted to resist attack by these antimicrobial compounds. In this review, we focus on the membrane phospholipid changes associated with daptomycin resistance in enterococci, Staphylococcus aureus, and the Viridans group streptococci.
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Affiliation(s)
- April H. Nguyen
- Center for Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, United States,Division of Infectious Diseases, Department of Medicine, Houston Methodist Hospital, Houston, TX, United States
| | - Kara S. Hood
- Center for Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, United States,Division of Infectious Diseases, Department of Medicine, Houston Methodist Hospital, Houston, TX, United States
| | - Eugenia Mileykovskaya
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center, Houston, TX, United States
| | - William R. Miller
- Center for Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, United States,Division of Infectious Diseases, Department of Medicine, Houston Methodist Hospital, Houston, TX, United States
| | - Truc T. Tran
- Center for Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, United States,Division of Infectious Diseases, Department of Medicine, Houston Methodist Hospital, Houston, TX, United States,*Correspondence: Truc T. Tran,
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15
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Biofilm antimicrobial susceptibility through an experimental evolutionary lens. NPJ Biofilms Microbiomes 2022; 8:82. [PMID: 36257971 PMCID: PMC9579162 DOI: 10.1038/s41522-022-00346-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 10/04/2022] [Indexed: 11/19/2022] Open
Abstract
Experimental evolution experiments in which bacterial populations are repeatedly exposed to an antimicrobial treatment, and examination of the genotype and phenotype of the resulting evolved bacteria, can help shed light on mechanisms behind reduced susceptibility. In this review we present an overview of why it is important to include biofilms in experimental evolution, which approaches are available to study experimental evolution in biofilms and what experimental evolution has taught us about tolerance and resistance in biofilms. Finally, we present an emerging consensus view on biofilm antimicrobial susceptibility supported by data obtained during experimental evolution studies.
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16
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Abstract
Enterococci are major, recalcitrant nosocomial pathogens with a wide repertoire of intrinsic and acquired resistance determinants and the potential of developing resistance to all clinically available antimicrobials. As such, multidrug-resistant enterococci are considered a serious public health threat. Due to limited treatment options and rapid emergence of resistance to all novel agents, the clinical microbiology laboratory plays a critical role in deploying accurate, reproducible, and feasible antimicrobial susceptibility testing methods to guide appropriate treatment of patients with deep-seated enterococcal infections. In this review, we provide an overview of the advantages and disadvantages of existing manual and automated methods that test susceptibility of Enterococcus faecium and Enterococcus faecalis to β-lactams, aminoglycosides, vancomycin, lipoglycopeptides, oxazolidinones, novel tetracycline-derivatives, and daptomycin. We also identify unique problems and gaps with the performance and clinical utility of antimicrobial susceptibility testing for enterococci, provide recommendations for clinical laboratories to circumvent select problems, and address potential future innovations that can bridge major gaps in susceptibility testing.
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17
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Antimicrobial tolerance and its role in the development of resistance: Lessons from enterococci. Adv Microb Physiol 2022; 81:25-65. [PMID: 36167442 DOI: 10.1016/bs.ampbs.2022.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Bacteria have developed resistance against every antimicrobial in clinical use at an alarming rate. There is a critical need for more effective use of antimicrobials to both extend their shelf life and prevent resistance from arising. Significantly, antimicrobial tolerance, i.e., the ability to survive but not proliferate during antimicrobial exposure, has been shown to precede the development of bona fide antimicrobial resistance (AMR), sparking a renewed and rapidly increasing interest in this field. As a consequence, problematic infections for the first time are now being investigated for antimicrobial tolerance, with increasing reports demonstrating in-host evolution of antimicrobial tolerance. Tolerance has been identified in a wide array of bacterial species to all bactericidal antimicrobials. Of particular interest are enterococci, which contain the opportunistic bacterial pathogens Enterococcus faecalis and Enterococcus faecium. Enterococci are one of the leading causes of hospital-acquired infection and possess intrinsic tolerance to a number of antimicrobial classes. Persistence of these infections in the clinic is of growing concern, particularly for the immunocompromised. Here, we review current known mechanisms of antimicrobial tolerance, and include an in-depth analysis of those identified in enterococci with implications for both the development and prevention of AMR.
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18
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Evolution of Enterococcus faecium in Response to a Combination of Daptomycin and Fosfomycin Reveals Distinct and Diverse Adaptive Strategies. Antimicrob Agents Chemother 2022; 66:e0233321. [PMID: 35543524 PMCID: PMC9211409 DOI: 10.1128/aac.02333-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Infections caused by vancomycin-resistant Enterococcus faecium (VREfm) are an important public health threat. VREfm isolates have become increasingly resistant to the front-line antibiotic daptomycin (DAP). As such, the use of DAP combination therapies with other antibiotics like fosfomycin (FOS) has received increased attention. Antibiotic combinations could extend the efficacy of currently available antibiotics and potentially delay the onset of further resistance. We investigated the potential for E. faecium HOU503, a clinical VREfm isolate that is DAP and FOS susceptible, to develop resistance to a DAP-FOS combination. Of particular interest was whether the genetic drivers for DAP-FOS resistance might be epistatic and, thus, potentially decrease the efficacy of a combinatorial approach in either inhibiting VREfm or in delaying the onset of resistance. We show that resistance to DAP-FOS could be achieved by independent mutations to proteins responsible for cell wall synthesis for FOS and in altering membrane dynamics for DAP. However, we did not observe genetic drivers that exhibited substantial cross-drug epistasis that could undermine the DAP-FOS combination. Of interest was that FOS resistance in HOU503 was largely mediated by changes in phosphoenolpyruvate (PEP) flux as a result of mutations in pyruvate kinase (pyk). Increasing PEP flux could be a readily accessible mechanism for FOS resistance in many pathogens. Importantly, we show that HOU503 was able to develop DAP resistance through a variety of biochemical mechanisms and was able to employ different adaptive strategies. Finally, we showed that the addition of FOS can prolong the efficacy of DAP and slow down DAP resistance in vitro.
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19
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Gargis AS, Spicer LM, Kent AG, Zhu W, Campbell D, McAllister G, Ewing TO, Albrecht V, Stevens VA, Sheth M, Padilla J, Batra D, Johnson JK, Halpin AL, Rasheed JK, Elkins CA, Karlsson M, Lutgring JD. Sentinel Surveillance Reveals Emerging Daptomycin-Resistant ST736 Enterococcus faecium and Multiple Mechanisms of Linezolid Resistance in Enterococci in the United States. Front Microbiol 2022; 12:807398. [PMID: 35178041 PMCID: PMC8846945 DOI: 10.3389/fmicb.2021.807398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 12/09/2021] [Indexed: 01/09/2023] Open
Abstract
Enterococcus faecalis and faecium with resistance to daptomycin and/or linezolid are emerging globally. We present the genomic characterization of daptomycin- and linezolid-resistant E. faecalis and E. faecium surveillance isolates from the United States, 2013-2016. Daptomycin resistance was low among E. faecalis (2/364, 0.5%) and E. faecium (17/344, 5%). The majority (71%, 12/17) of daptomycin-resistant E. faecium isolates belonged to the emerging ST736 clone and contained mutations in liaFSR and cls previously associated with resistance. However, 1/2 E. faecalis and 3/17 E. faecium did not contain these mutations previously associated with daptomycin resistance. Linezolid resistance was rare among E. faecalis (1/364, 0.3%) and E. faecium (2/344, 0.6%). These two E. faecium isolates, one of which was also resistant to daptomycin and vancomycin, contained the 23S rRNA nucleotide mutation (G2576T) associated with linezolid resistance. Long-read sequencing revealed the linezolid-resistant E. faecalis isolate contained chromosomal- and plasmid-encoded copies of optrA. The chromosomal optrA was located on the recently described Tn6674 multiresistance transposon. The second copy of optrA was encoded on an ∼65 kb mosaic plasmid, with component regions sharing high sequence identity to optrA-encoding multiresistance plasmids of animal origin. The optrA-encoding plasmid contained open reading frames predicted to encode proteins associated with a pheromone-responsive plasmid transfer system, and filter mating experiments confirmed the plasmid was conjugative. Continued surveillance of enterococci is necessary to assess the prevalence and trends of daptomycin and linezolid resistance in the United States, characterize resistance mechanisms and how they transfer, and monitor for emerging sequence types associated with resistance.
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Affiliation(s)
- Amy S. Gargis
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Lori M. Spicer
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
- Goldbelt C6, LLC, Chesapeake, VA, United States
| | - Alyssa G. Kent
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
- Goldbelt C6, LLC, Chesapeake, VA, United States
| | - Wenming Zhu
- Division of Tuberculosis Elimination, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Davina Campbell
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Gillian McAllister
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Thomas O. Ewing
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
- Goldbelt C6, LLC, Chesapeake, VA, United States
| | - Valerie Albrecht
- Office of the Director, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Valerie A. Stevens
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Mili Sheth
- Biotechnology Core Facility Branch, Division of Scientific Resources, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Jasmine Padilla
- Biotechnology Core Facility Branch, Division of Scientific Resources, Centers for Disease Control and Prevention, Atlanta, GA, United States
- ASRT Incorporated, Atlanta, GA, United States
| | - Dhwani Batra
- Biotechnology Core Facility Branch, Division of Scientific Resources, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - J. Kristie Johnson
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Alison Laufer Halpin
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - J. Kamile Rasheed
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Christopher A. Elkins
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Maria Karlsson
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Joseph D. Lutgring
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
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20
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Horton JS, Flanagan LM, Jackson RW, Priest NK, Taylor TB. A mutational hotspot that determines highly repeatable evolution can be built and broken by silent genetic changes. Nat Commun 2021; 12:6092. [PMID: 34667151 PMCID: PMC8526746 DOI: 10.1038/s41467-021-26286-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 09/28/2021] [Indexed: 11/08/2022] Open
Abstract
Mutational hotspots can determine evolutionary outcomes and make evolution repeatable. Hotspots are products of multiple evolutionary forces including mutation rate heterogeneity, but this variable is often hard to identify. In this work, we reveal that a near-deterministic genetic hotspot can be built and broken by a handful of silent mutations. We observe this when studying homologous immotile variants of the bacteria Pseudomonas fluorescens, AR2 and Pf0-2x. AR2 resurrects motility through highly repeatable de novo mutation of the same nucleotide in >95% lines in minimal media (ntrB A289C). Pf0-2x, however, evolves via a number of mutations meaning the two strains diverge significantly during adaptation. We determine that this evolutionary disparity is owed to just 6 synonymous variations within the ntrB locus, which we demonstrate by swapping the sites and observing that we are able to both break (>95% to 0%) and build (0% to 80%) a deterministic mutational hotspot. Our work reveals a key role for silent genetic variation in determining adaptive outcomes.
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Affiliation(s)
- James S Horton
- Milner Centre for Evolution, Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| | - Louise M Flanagan
- Milner Centre for Evolution, Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Robert W Jackson
- School of Biosciences and Birmingham Institute of Forest Research (BIFoR), University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Nicholas K Priest
- Milner Centre for Evolution, Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Tiffany B Taylor
- Milner Centre for Evolution, Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
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21
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Wong GCL, Antani JD, Lele PP, Chen J, Nan B, Kühn MJ, Persat A, Bru JL, Høyland-Kroghsbo NM, Siryaporn A, Conrad JC, Carrara F, Yawata Y, Stocker R, Brun YV, Whitfield GB, Lee CK, de Anda J, Schmidt WC, Golestanian R, O’Toole GA, Floyd KA, Yildiz FH, Yang S, Jin F, Toyofuku M, Eberl L, Nomura N, Zacharoff LA, El-Naggar MY, Yalcin SE, Malvankar NS, Rojas-Andrade MD, Hochbaum AI, Yan J, Stone HA, Wingreen NS, Bassler BL, Wu Y, Xu H, Drescher K, Dunkel J. Roadmap on emerging concepts in the physical biology of bacterial biofilms: from surface sensing to community formation. Phys Biol 2021; 18:10.1088/1478-3975/abdc0e. [PMID: 33462162 PMCID: PMC8506656 DOI: 10.1088/1478-3975/abdc0e] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 01/14/2021] [Indexed: 11/29/2022]
Abstract
Bacterial biofilms are communities of bacteria that exist as aggregates that can adhere to surfaces or be free-standing. This complex, social mode of cellular organization is fundamental to the physiology of microbes and often exhibits surprising behavior. Bacterial biofilms are more than the sum of their parts: single-cell behavior has a complex relation to collective community behavior, in a manner perhaps cognate to the complex relation between atomic physics and condensed matter physics. Biofilm microbiology is a relatively young field by biology standards, but it has already attracted intense attention from physicists. Sometimes, this attention takes the form of seeing biofilms as inspiration for new physics. In this roadmap, we highlight the work of those who have taken the opposite strategy: we highlight the work of physicists and physical scientists who use physics to engage fundamental concepts in bacterial biofilm microbiology, including adhesion, sensing, motility, signaling, memory, energy flow, community formation and cooperativity. These contributions are juxtaposed with microbiologists who have made recent important discoveries on bacterial biofilms using state-of-the-art physical methods. The contributions to this roadmap exemplify how well physics and biology can be combined to achieve a new synthesis, rather than just a division of labor.
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Affiliation(s)
- Gerard C L Wong
- Department of Bioengineering, University of California—Los Angeles, Los Angeles, California, CA 90095, United States of America
- Department of Chemistry and Biochemistry, University of California—Los Angeles, Los Angeles, California, CA 90095, United States of America
- California NanoSystems Institute, University of California—Los Angeles, Los Angeles, California, CA 90095, United States of America
| | - Jyot D Antani
- Artie McFerrin Department of Chemical Engineering, Texas A & M University, College Station, TX 77843, United States of America
| | - Pushkar P Lele
- Artie McFerrin Department of Chemical Engineering, Texas A & M University, College Station, TX 77843, United States of America
| | - Jing Chen
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA24061, United States of America
| | - Beiyan Nan
- Department of Biology, Texas A & M University, College Station, Texas, TX 77845, United States of America
| | - Marco J Kühn
- Institute of Bioengineering and Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Alexandre Persat
- Institute of Bioengineering and Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Jean-Louis Bru
- Department of Molecular Biology & Biochemistry, University of California—Irvine, California, CA 92697, United States of America
| | | | - Albert Siryaporn
- Department of Molecular Biology & Biochemistry, University of California—Irvine, California, CA 92697, United States of America
- Department of Physics & Astronomy, University of California—Irvine, California, CA 92697, United States of America
| | - Jacinta C Conrad
- William A Brookshire Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas, TX 77204, United States of America
| | - Francesco Carrara
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, 8093 Zurich, Switzerland
| | - Yutaka Yawata
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
- Microbiology Research Center for Sustainability, University of Tsukuba, 305-8572 Tsukuba, Japan
| | - Roman Stocker
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, 8093 Zurich, Switzerland
| | - Yves V Brun
- University of Montreal, Faculty of Medicine, Montreal, Quebec, H3C 3J7, Canada
| | - Gregory B Whitfield
- University of Montreal, Faculty of Medicine, Montreal, Quebec, H3C 3J7, Canada
| | - Calvin K Lee
- Department of Bioengineering, University of California—Los Angeles, Los Angeles, California, CA 90095, United States of America
- Department of Chemistry and Biochemistry, University of California—Los Angeles, Los Angeles, California, CA 90095, United States of America
- California NanoSystems Institute, University of California—Los Angeles, Los Angeles, California, CA 90095, United States of America
| | - Jaime de Anda
- Department of Bioengineering, University of California—Los Angeles, Los Angeles, California, CA 90095, United States of America
- Department of Chemistry and Biochemistry, University of California—Los Angeles, Los Angeles, California, CA 90095, United States of America
- California NanoSystems Institute, University of California—Los Angeles, Los Angeles, California, CA 90095, United States of America
| | - William C Schmidt
- Department of Bioengineering, University of California—Los Angeles, Los Angeles, California, CA 90095, United States of America
- Department of Chemistry and Biochemistry, University of California—Los Angeles, Los Angeles, California, CA 90095, United States of America
- California NanoSystems Institute, University of California—Los Angeles, Los Angeles, California, CA 90095, United States of America
| | - Ramin Golestanian
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), D-37077 Göttingen, Germany
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - George A O’Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, United States of America
| | - Kyle A Floyd
- Department of Microbiology and Environmental Toxicology, University of California—Santa Cruz, Santa Cruz, California, CA 95060, United States of America
| | - Fitnat H Yildiz
- Department of Microbiology and Environmental Toxicology, University of California—Santa Cruz, Santa Cruz, California, CA 95060, United States of America
| | - Shuai Yang
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, People’s Republic of China
| | - Fan Jin
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, People’s Republic of China
| | - Masanori Toyofuku
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
- Microbiology Research Center for Sustainability, University of Tsukuba, 305-8572 Tsukuba, Japan
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland
| | - Nobuhiko Nomura
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
- Microbiology Research Center for Sustainability, University of Tsukuba, 305-8572 Tsukuba, Japan
| | - Lori A Zacharoff
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California, CA 90089, United States of America
- Department of Chemistry, University of Southern California, Los Angeles, California, CA 90089, United States of America
| | - Mohamed Y El-Naggar
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California, CA 90089, United States of America
- Department of Chemistry, University of Southern California, Los Angeles, California, CA 90089, United States of America
- Department of Biological Sciences, University of Southern California, Los Angeles, California, CA 90089, United States of America
| | - Sibel Ebru Yalcin
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, CT 06516, United States of America
- Microbial Sciences Institute, Yale University, New Haven, Connecticut, CT 06516, United States of America
| | - Nikhil S Malvankar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, CT 06516, United States of America
- Microbial Sciences Institute, Yale University, New Haven, Connecticut, CT 06516, United States of America
| | - Mauricio D Rojas-Andrade
- Department of Materials Science and Engineering, University of California—Irvine, Irvine, California CA 92697, United States of America
| | - Allon I Hochbaum
- Department of Molecular Biology & Biochemistry, University of California—Irvine, California, CA 92697, United States of America
- Department of Materials Science and Engineering, University of California—Irvine, Irvine, California CA 92697, United States of America
- Department of Chemistry, University of California—Irvine, Irvine, California, CA 92697, United States of America
- Department of Chemical and Biomolecular Engineering, University of California—Irvine, Irvine, California, CA 92697, United States of America
| | - Jing Yan
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, CT 06511, United States of America
| | - Howard A Stone
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey, NJ 08544, United States of America
| | - Ned S Wingreen
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, NJ 08544, United States of America
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, NJ 08544, United States of America
| | - Bonnie L Bassler
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, NJ 08544, United States of America
- The Howard Hughes Medical Institute, Chevy Chase, Maryland MD 20815, United States of America
| | - Yilin Wu
- Department of Physics and Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People’s Republic of China
| | - Haoran Xu
- Department of Physics and Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People’s Republic of China
| | - Knut Drescher
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
- Department of Physics, Philipps-Universität Marburg, 35043 Marburg, Germany
| | - Jörn Dunkel
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts, MA 02139-4307, United States of America
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22
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Daptomycin Resistance in Enterococcus faecium Can Be Delayed by Disruption of the LiaFSR Stress Response Pathway. Antimicrob Agents Chemother 2021; 65:AAC.01317-20. [PMID: 33468468 DOI: 10.1128/aac.01317-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 01/08/2021] [Indexed: 01/01/2023] Open
Abstract
LiaFSR signaling plays a major role in mediating daptomycin (DAP) resistance in enterococci, and the lack of a functional LiaFSR pathway leads to DAP hypersusceptibility. Using in vitro experimental evolution, we evaluated how Enterococcus faecium with a liaR response regulator gene deletion evolved DAP resistance. We found that knocking out LiaFSR signaling significantly delayed the onset of resistance, but resistance could emerge eventually through various alternate mechanisms that were influenced by the environment.
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23
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Abstract
Serious infections owing to vancomycin-resistant enterococci have historically proven to be difficult clinical cases, requiring combination therapy and management of treatment-related toxicity. Despite the introduction of new antibiotics with activity against vancomycin-resistant enterococci to the therapeutic armamentarium, significant challenges remain. An understanding of the factors driving the emergence of resistance in vancomycin-resistant enterococci, the dynamics of gastrointestinal colonization and microbiota-mediated colonization resistance, and the mechanisms of resistance to the currently available therapeutics will permit clinicians to be better prepared to tackle these challenging hospital-associated pathogens.
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Affiliation(s)
- William R Miller
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Health Science Center at Houston, McGovern Medical School, 6431 Fannin St. MSB 2.112, Houston, TX 77030, USA; Center for Antimicrobial Resistance and Microbial Genomics (CARMiG)
| | - Barbara E Murray
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Health Science Center at Houston, McGovern Medical School, 6431 Fannin St. MSB 2.112, Houston, TX 77030, USA; Center for Antimicrobial Resistance and Microbial Genomics (CARMiG); Department of Microbiology and Molecular Genetics, 6431 Fannin St. MSB 2.112, Houston, TX 77030, USA
| | - Louis B Rice
- Department of Internal Medicine, Brown University, 593 Eddy Street, Providence, RI 02903, USA
| | - Cesar A Arias
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Health Science Center at Houston, McGovern Medical School, 6431 Fannin St. MSB 2.112, Houston, TX 77030, USA; Center for Antimicrobial Resistance and Microbial Genomics (CARMiG); Department of Microbiology and Molecular Genetics, 6431 Fannin St. MSB 2.112, Houston, TX 77030, USA; University of Texas Health Science Center at Houston, School of Public Health, Houston, TX, USA; Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, Bogota, Colombia.
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24
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Thitiananpakorn K, Aiba Y, Tan XE, Watanabe S, Kiga K, Sato'o Y, Boonsiri T, Li FY, Sasahara T, Taki Y, Azam AH, Zhang Y, Cui L. Association of mprF mutations with cross-resistance to daptomycin and vancomycin in methicillin-resistant Staphylococcus aureus (MRSA). Sci Rep 2020; 10:16107. [PMID: 32999359 PMCID: PMC7527455 DOI: 10.1038/s41598-020-73108-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 08/24/2020] [Indexed: 12/11/2022] Open
Abstract
We first reported a phenomenon of cross-resistance to vancomycin (VCM) and daptomycin (DAP) in methicillin-resistant Staphylococcus aureus (MRSA) in 2006, but mechanisms underlying the cross-resistance remain incompletely understood. Here, we present a follow-up study aimed to investigate genetic determinants associated with the cross-resistance. Using 12 sets of paired DAP susceptible (DAPS) and DAP non-susceptible (DAPR) MRSA isolates from 12 patients who had DAP therapy, we (i) assessed susceptibility to DAP and VCM, (ii) compared whole-genome sequences, (iii) identified mutations associated with cross-resistance to DAP and VCM, and (iv) investigated the impact of altered gene expression and metabolic pathway relevant to the cross-resistance. We found that all 12 DAPR strains exhibiting cross-resistance to DAP and VCM carried mutations in mprF, while one DAPR strain with reduced susceptibility to only DAP carried a lacF mutation. On the other hand, among the 32 vancomycin-intermediate S. aureus (VISA) strains isolated from patients treated with VCM, five out of the 18 strains showing cross-resistance to DAP and VCM carried a mprF mutation, while 14 strains resistant to only VCM had no mprF mutation. Moreover, substitution of mprF in a DAPS strain with mutated mprF resulted in cross-resistance and vice versa. The elevated lysyl-phosphatidylglycerol (L-PG) production, increased positive bacterial surface charges and activated cell wall (CW) synthetic pathways were commonly found in both clinical isolates and laboratory-developed mutants that carry mprF mutations. We conclude that mprF mutation is responsible for the cross-resistance of MRSA to DAP and VCM, and treatment with DAP is more likely to select for mprF-mediated cross-resistance than is with VCM.
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Affiliation(s)
- Kanate Thitiananpakorn
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Yoshifumi Aiba
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Xin-Ee Tan
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Shinya Watanabe
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Kotaro Kiga
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Yusuke Sato'o
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Tanit Boonsiri
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Feng-Yu Li
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Teppei Sasahara
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Yusuke Taki
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Aa Haeruman Azam
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Yuancheng Zhang
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Longzhu Cui
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan.
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25
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Karas JA, Carter GP, Howden BP, Turner AM, Paulin OKA, Swarbrick JD, Baker MA, Li J, Velkov T. Structure–Activity Relationships of Daptomycin Lipopeptides. J Med Chem 2020; 63:13266-13290. [DOI: 10.1021/acs.jmedchem.0c00780] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- John A. Karas
- Department of Pharmacology & Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Glen P. Carter
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Benjamin P. Howden
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Adrianna M. Turner
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Olivia K. A. Paulin
- Department of Pharmacology & Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - James D. Swarbrick
- Department of Pharmacology & Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Mark. A. Baker
- Priority Research Centre in Reproductive Science, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Jian Li
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Tony Velkov
- Department of Pharmacology & Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
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26
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Meng L, Liu H, Lan T, Dong L, Hu H, Zhao S, Zhang Y, Zheng N, Wang J. Antibiotic Resistance Patterns of Pseudomonas spp. Isolated From Raw Milk Revealed by Whole Genome Sequencing. Front Microbiol 2020; 11:1005. [PMID: 32655503 PMCID: PMC7326020 DOI: 10.3389/fmicb.2020.01005] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 04/24/2020] [Indexed: 12/11/2022] Open
Abstract
Psychrotrophic bacteria in raw milk are most well known for their spoilage potential and the economic losses they cause to the dairy industry. Food-related psychrotrophic bacteria are increasingly reported to have antibiotic resistance features. The aim of this study was to evaluate the resistance patterns of Pseudomonas spp. isolated from bulk-tank milk. In total, we investigated the antibiotic susceptibility profiles of 86 Pseudomonas spp. isolates from raw milk. All strains were tested against 15 antimicrobial agents. Pseudomonas isolates were most highly resistant to imipenem (95.3%), followed by trimethoprim-sulfamethoxazole (69.8%), aztreonam (60.5%), chloramphenicol (45.3%), and meropenem (27.9%). Their multiple antibiotic resistance (MAR) index values ranged from 0.0 to 0.8. Whole-genome sequencing revealed the presence of intrinsic resistance determinants, such as BcI, ampC-09, blaCTX-M, oprD, sul1, dfrE, catA1, catB3, catI, floR, and cmlV. Moreover, resistance-nodulation-cell division (RND) and ATP-binding cassette (ABC) antibiotic efflux pumps were also found. This study provides further knowledge of the antibiotic resistance patterns of Pseudomonas spp. in milk, which may advance our understanding of resistance in Pseudomonas and suggests that antibiotic resistance of Pseudomonas spp. in raw milk should be a concern.
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Affiliation(s)
- Lu Meng
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Huimin Liu
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Tu Lan
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Lei Dong
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Haiyan Hu
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,College of Animal Science and Technology, Anhui Agricultural University, Hefei, China
| | - Shengguo Zhao
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yangdong Zhang
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Nan Zheng
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jiaqi Wang
- Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
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27
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Mehta HH, Shamoo Y. Pathogenic Nocardia: A diverse genus of emerging pathogens or just poorly recognized? PLoS Pathog 2020; 16:e1008280. [PMID: 32134995 PMCID: PMC7058287 DOI: 10.1371/journal.ppat.1008280] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Heer H. Mehta
- Department of BioSciences, Rice University, Houston, Texas, United States of America
- * E-mail:
| | - Yousif Shamoo
- Department of BioSciences, Rice University, Houston, Texas, United States of America
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28
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Rincon S, Panesso D, Miller WR, Singh KV, Cruz MR, Khan A, Dinh AQ, Diaz L, Rios R, Shamoo Y, Reyes J, Tran TT, Garsin DA, Arias CA. Disrupting Membrane Adaptation Restores In Vivo Efficacy of Antibiotics Against Multidrug-Resistant Enterococci and Potentiates Killing by Human Neutrophils. J Infect Dis 2020; 220:494-504. [PMID: 30938438 DOI: 10.1093/infdis/jiz131] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/22/2019] [Indexed: 12/17/2022] Open
Abstract
Daptomycin resistance in enterococci is often mediated by the LiaFSR system, which orchestrates the cell membrane stress response. Activation of LiaFSR through the response regulator LiaR generates major changes in cell membrane function and architecture (membrane adaptive response), permitting the organism to survive the antibiotic attack. Here, using a laboratory strain of Enterococcus faecalis, we developed a novel Caenorhabditis elegans model of daptomycin therapy and showed that disrupting LiaR-mediated cell membrane adaptation restores the in vivo activity of daptomycin. The LiaR effect was also seen in a clinical strain of daptomycin-resistant Enterococcus faecium, using a murine model of peritonitis. Furthermore, alteration of the cell membrane response increased the ability of human polymorphonuclear neutrophils to readily clear both E. faecalis and multidrug-resistant E. faecium. Our results provide proof of concept that targeting the cell membrane adaptive response restores the in vivo activity of antibiotics, prevents resistance, and enhances the ability of the innate immune system to kill infecting bacteria.
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Affiliation(s)
- Sandra Rincon
- Center for Antimicrobial Resistance and Microbial Genomics, Rice University.,Molecular Genetics and Antimicrobial Resistance Unit and International Center for Microbial Genomics, Universidad El Bosque, Bogota, Colombia
| | - Diana Panesso
- Center for Antimicrobial Resistance and Microbial Genomics, Rice University.,Department of Internal Medicine, Division of Infectious Diseases, Rice University.,Molecular Genetics and Antimicrobial Resistance Unit and International Center for Microbial Genomics, Universidad El Bosque, Bogota, Colombia
| | - William R Miller
- Center for Antimicrobial Resistance and Microbial Genomics, Rice University.,Department of Internal Medicine, Division of Infectious Diseases, Rice University
| | - Kavindra V Singh
- Center for Antimicrobial Resistance and Microbial Genomics, Rice University.,Department of Internal Medicine, Division of Infectious Diseases, Rice University
| | - Melissa R Cruz
- Department of Microbiology and Molecular Genetics, UTHealth McGovern Medical School, Rice University
| | - Ayesha Khan
- Center for Antimicrobial Resistance and Microbial Genomics, Rice University.,Department of Microbiology and Molecular Genetics, UTHealth McGovern Medical School, Rice University
| | - An Q Dinh
- Center for Antimicrobial Resistance and Microbial Genomics, Rice University.,Department of Internal Medicine, Division of Infectious Diseases, Rice University
| | - Lorena Diaz
- Center for Antimicrobial Resistance and Microbial Genomics, Rice University.,Molecular Genetics and Antimicrobial Resistance Unit and International Center for Microbial Genomics, Universidad El Bosque, Bogota, Colombia
| | - Rafael Rios
- Molecular Genetics and Antimicrobial Resistance Unit and International Center for Microbial Genomics, Universidad El Bosque, Bogota, Colombia
| | | | - Jinnethe Reyes
- Center for Antimicrobial Resistance and Microbial Genomics, Rice University.,Molecular Genetics and Antimicrobial Resistance Unit and International Center for Microbial Genomics, Universidad El Bosque, Bogota, Colombia
| | - Truc T Tran
- Center for Antimicrobial Resistance and Microbial Genomics, Rice University.,Department of Internal Medicine, Division of Infectious Diseases, Rice University
| | - Danielle A Garsin
- Center for Antimicrobial Resistance and Microbial Genomics, Rice University.,Department of Microbiology and Molecular Genetics, UTHealth McGovern Medical School, Rice University
| | - Cesar A Arias
- Center for Antimicrobial Resistance and Microbial Genomics, Rice University.,Department of Internal Medicine, Division of Infectious Diseases, Rice University.,Department of Microbiology and Molecular Genetics, UTHealth McGovern Medical School, Rice University.,Center for Infectious Diseases, School of Public Health, University of Texas Health Science Center, Houston, Texas.,Molecular Genetics and Antimicrobial Resistance Unit and International Center for Microbial Genomics, Universidad El Bosque, Bogota, Colombia
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29
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Chilambi GS, Hinks J, Matysik A, Zhu X, Choo PY, Liu X, Chan-Park MB, Bazan GC, Kline KA, Rice SA. Enterococcus faecalis Adapts to Antimicrobial Conjugated Oligoelectrolytes by Lipid Rearrangement and Differential Expression of Membrane Stress Response Genes. Front Microbiol 2020; 11:155. [PMID: 32117172 PMCID: PMC7033496 DOI: 10.3389/fmicb.2020.00155] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 01/22/2020] [Indexed: 11/17/2022] Open
Abstract
Conjugated oligoelectrolytes (COEs) are emerging antimicrobials with broad spectrum activity against Gram positive and Gram negative bacteria as well as fungi. Our previous in vitro evolution studies using Enterococcus faecalis grown in the presence of two related COEs (COE1-3C and COE1-3Py) led to the emergence of mutants (changes in liaF and liaR) with a moderate 4- to16-fold increased resistance to COEs. The contribution of liaF and liaR mutations to COE resistance was confirmed by complementation of the mutants, which restored sensitivity to COEs. To better understand the cellular target of COEs, and the mechanism of resistance to COEs, transcriptional changes associated with resistance in the evolved mutants were investigated in this study. The differentially transcribed genes encoded membrane transporters, in addition to proteins associated with cell envelope synthesis and stress responses. Genes encoding membrane transport proteins from the ATP binding cassette superfamily were the most significantly induced or repressed in COE tolerant mutants compared to the wild type when exposed to COEs. Additionally, differences in the membrane localization of a lipophilic dye in E. faecalis exposed to COEs suggested that resistance was associated with lipid rearrangement in the cell membrane. The membrane adaptation to COEs in EFC3C and EFC3Py resulted in an improved tolerance to bile salt and sodium chloride stress. Overall, this study showed that bacterial cell membranes are the primary target of COEs and that E. faecalis adapts to membrane interacting COE molecules by both lipid rearrangement and changes in membrane transporter activity. The level of resistance to COEs suggests that E. faecalis does not have a specific response pathway to elicit resistance against these molecules and this is supported by the rather broad and diverse suite of genes that are induced upon COE exposure as well as cross-resistance to membrane perturbing stressors.
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Affiliation(s)
- Gayatri Shankar Chilambi
- Interdisciplinary Graduate School, Nanyang Technological University, Singapore, Singapore
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Jamie Hinks
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Artur Matysik
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Xinyi Zhu
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Pei Yi Choo
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Xianghui Liu
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Mary B. Chan-Park
- School of Chemical and Biomedical Engineering, College of Engineering, Nanyang Technological University, Singapore, Singapore
| | - Guillermo C. Bazan
- School of Chemical and Biomedical Engineering, College of Engineering, Nanyang Technological University, Singapore, Singapore
- Center for Polymers and Organic Solids, Department of Chemistry and Biochemistry and Materials, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Kimberly A. Kline
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Scott A. Rice
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- The ithree Institute, University of Technology Sydney, Sydney, NSW, Australia
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30
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Khan A, Davlieva M, Panesso D, Rincon S, Miller WR, Diaz L, Reyes J, Cruz MR, Pemberton O, Nguyen AH, Siegel SD, Planet PJ, Narechania A, Latorre M, Rios R, Singh KV, Ton-That H, Garsin DA, Tran TT, Shamoo Y, Arias CA. Antimicrobial sensing coupled with cell membrane remodeling mediates antibiotic resistance and virulence in Enterococcus faecalis. Proc Natl Acad Sci U S A 2019; 116:26925-26932. [PMID: 31818937 PMCID: PMC6936494 DOI: 10.1073/pnas.1916037116] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Bacteria have developed several evolutionary strategies to protect their cell membranes (CMs) from the attack of antibiotics and antimicrobial peptides (AMPs) produced by the innate immune system, including remodeling of phospholipid content and localization. Multidrug-resistant Enterococcus faecalis, an opportunistic human pathogen, evolves resistance to the lipopeptide daptomycin and AMPs by diverting the antibiotic away from critical septal targets using CM anionic phospholipid redistribution. The LiaFSR stress response system regulates this CM remodeling via the LiaR response regulator by a previously unknown mechanism. Here, we characterize a LiaR-regulated protein, LiaX, that senses daptomycin or AMPs and triggers protective CM remodeling. LiaX is surface exposed, and in daptomycin-resistant clinical strains, both LiaX and the N-terminal domain alone are released into the extracellular milieu. The N-terminal domain of LiaX binds daptomycin and AMPs (such as human LL-37) and functions as an extracellular sentinel that activates the cell envelope stress response. The C-terminal domain of LiaX plays a role in inhibiting the LiaFSR system, and when this domain is absent, it leads to activation of anionic phospholipid redistribution. Strains that exhibit LiaX-mediated CM remodeling and AMP resistance show enhanced virulence in the Caenorhabditis elegans model, an effect that is abolished in animals lacking an innate immune pathway crucial for producing AMPs. In conclusion, we report a mechanism of antibiotic and AMP resistance that couples bacterial stress sensing to major changes in CM architecture, ultimately also affecting host-pathogen interactions.
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Affiliation(s)
- Ayesha Khan
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- MD Anderson Cancer Center, University of Texas Health Graduate School of Biomedical Sciences, Houston, TX 77030
| | - Milya Davlieva
- Department of Biosciences, Rice University, Houston, TX 77005
| | - Diana Panesso
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, 110111 Bogotá, Colombia
| | - Sandra Rincon
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, 110111 Bogotá, Colombia
| | - William R. Miller
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
| | - Lorena Diaz
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, 110111 Bogotá, Colombia
- Millennium Initiative for Collaborative Research On Bacterial Resistance (MICROB-R), 8320000 Santiago, Chile
| | - Jinnethe Reyes
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, 110111 Bogotá, Colombia
| | - Melissa R. Cruz
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
| | | | - April H. Nguyen
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- MD Anderson Cancer Center, University of Texas Health Graduate School of Biomedical Sciences, Houston, TX 77030
| | - Sara D. Siegel
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
| | - Paul J. Planet
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
- Pediatric Infectious Disease Division, Children’s Hospital of Philadelphia, Philadelphia, PA
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY 12560
| | - Apurva Narechania
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY 12560
| | - Mauricio Latorre
- Center for Genome Regulation and Center for Mathematical Modeling, Universidad de Chile, 8320000 Santiago, Chile
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, 8320000 Santiago, Chile
- Laboratorio de Biotecnología, Instituto de Ciencias de la Ingeniería, Universidad de O'Higgins, 2841158 Rancagua, Chile
| | - Rafael Rios
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, 110111 Bogotá, Colombia
| | - Kavindra V. Singh
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
| | - Hung Ton-That
- Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, CA 90024
| | - Danielle A. Garsin
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- MD Anderson Cancer Center, University of Texas Health Graduate School of Biomedical Sciences, Houston, TX 77030
| | - Truc T. Tran
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
| | - Yousif Shamoo
- Department of Biosciences, Rice University, Houston, TX 77005
| | - Cesar A. Arias
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030
- MD Anderson Cancer Center, University of Texas Health Graduate School of Biomedical Sciences, Houston, TX 77030
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, 110111 Bogotá, Colombia
- Center for Infectious Diseases, School of Public Health, University of Texas Health Science Center, Houston, TX 77030
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31
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Maltas J, Wood KB. Pervasive and diverse collateral sensitivity profiles inform optimal strategies to limit antibiotic resistance. PLoS Biol 2019; 17:e3000515. [PMID: 31652256 PMCID: PMC6834293 DOI: 10.1371/journal.pbio.3000515] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 11/06/2019] [Accepted: 10/07/2019] [Indexed: 11/19/2022] Open
Abstract
Evolved resistance to one antibiotic may be associated with "collateral" sensitivity to other drugs. Here, we provide an extensive quantitative characterization of collateral effects in Enterococcus faecalis, a gram-positive opportunistic pathogen. By combining parallel experimental evolution with high-throughput dose-response measurements, we measure phenotypic profiles of collateral sensitivity and resistance for a total of 900 mutant-drug combinations. We find that collateral effects are pervasive but difficult to predict because independent populations selected by the same drug can exhibit qualitatively different profiles of collateral sensitivity as well as markedly different fitness costs. Using whole-genome sequencing of evolved populations, we identified mutations in a number of known resistance determinants, including mutations in several genes previously linked with collateral sensitivity in other species. Although phenotypic drug sensitivity profiles show significant diversity, they cluster into statistically similar groups characterized by selecting drugs with similar mechanisms. To exploit the statistical structure in these resistance profiles, we develop a simple mathematical model based on a stochastic control process and use it to design optimal drug policies that assign a unique drug to every possible resistance profile. Stochastic simulations reveal that these optimal drug policies outperform intuitive cycling protocols by maintaining long-term sensitivity at the expense of short-term periods of high resistance. The approach reveals a new conceptual strategy for mitigating resistance by balancing short-term inhibition of pathogen growth with infrequent use of drugs intended to steer pathogen populations to a more vulnerable future state. Experiments in laboratory populations confirm that model-inspired sequences of four drugs reduce growth and slow adaptation relative to naive protocols involving the drugs alone, in pairwise cycles, or in a four-drug uniform cycle.
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Affiliation(s)
- Jeff Maltas
- Department of Biophysics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Kevin B. Wood
- Department of Biophysics, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Physics, University of Michigan, Ann Arbor, Michigan, United States of America
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32
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Environment Shapes the Accessible Daptomycin Resistance Mechanisms in Enterococcus faecium. Antimicrob Agents Chemother 2019; 63:AAC.00790-19. [PMID: 31332078 DOI: 10.1128/aac.00790-19] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 07/16/2019] [Indexed: 02/07/2023] Open
Abstract
Daptomycin binds to bacterial cell membranes and disrupts essential cell envelope processes, leading to cell death. Bacteria respond to daptomycin by altering their cell envelopes to either decrease antibiotic binding to the membrane or by diverting binding away from septal targets. In Enterococcus faecalis, daptomycin resistance is typically coordinated by the three-component cell envelope stress response system, LiaFSR. Here, studying a clinical strain of multidrug-resistant Enterococcus faecium containing alleles associated with activation of the LiaFSR signaling pathway, we found that specific environments selected for different evolutionary trajectories, leading to high-level daptomycin resistance. Planktonic environments favored pathways that increased cell surface charge via yvcRS upregulation of dltABCD and mprF, causing a reduction in daptomycin binding. Alternatively, environments favoring complex structured communities, including biofilms, evolved both diversion and repulsion strategies via divIVA and oatA mutations, respectively. Both environments subsequently converged on cardiolipin synthase (cls) mutations, suggesting the importance of membrane modification across strategies. Our findings indicate that E. faecium can evolve diverse evolutionary trajectories to daptomycin resistance that are shaped by the environment to produce a combination of resistance strategies. The accessibility of multiple and different biochemical pathways simultaneously suggests that the outcome of daptomycin exposure results in a polymorphic population of resistant phenotypes, making E. faecium a recalcitrant nosocomial pathogen.
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33
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The Essential Role of Hypermutation in Rapid Adaptation to Antibiotic Stress. Antimicrob Agents Chemother 2019; 63:AAC.00744-19. [PMID: 31036684 DOI: 10.1128/aac.00744-19] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 04/19/2019] [Indexed: 12/22/2022] Open
Abstract
A common outcome of antibiotic exposure in patients and in vitro is the evolution of a hypermutator phenotype that enables rapid adaptation by pathogens. While hypermutation is a robust mechanism for rapid adaptation, it requires trade-offs between the adaptive mutations and the more common "hitchhiker" mutations that accumulate from the increased mutation rate. Using quantitative experimental evolution, we examined the role of hypermutation in driving the adaptation of Pseudomonas aeruginosa to colistin. Metagenomic deep sequencing revealed 2,657 mutations at ≥5% frequency in 1,197 genes and 761 mutations in 29 endpoint isolates. By combining genomic information, phylogenetic analyses, and statistical tests, we showed that evolutionary trajectories leading to resistance could be reliably discerned. In addition to known alleles such as pmrB, hypermutation allowed identification of additional adaptive alleles with epistatic relationships. Although hypermutation provided a short-term fitness benefit, it was detrimental to overall fitness. Alarmingly, a small fraction of the colistin-adapted population remained colistin susceptible and escaped hypermutation. In a clinical population, such cells could play a role in reestablishing infection upon withdrawal of colistin. We present here a framework for evaluating the complex evolutionary trajectories of hypermutators that applies to both current and emerging pathogen populations.
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34
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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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35
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Miller WR, Tran TT, Diaz L, Rios R, Khan A, Reyes J, Prater AG, Panesso D, Shamoo Y, Arias CA. LiaR-independent pathways to daptomycin resistance in Enterococcus faecalis reveal a multilayer defense against cell envelope antibiotics. Mol Microbiol 2019; 111:811-824. [PMID: 30582877 PMCID: PMC6417935 DOI: 10.1111/mmi.14193] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2018] [Indexed: 12/17/2022]
Abstract
The lipopeptide antibiotic daptomycin (DAP) is a key drug against serious enterococcal infections, but the emergence of resistance in the clinical setting is a major concern. The LiaFSR system plays a prominent role in the development of DAP resistance (DAP-R) in enterococci, and blocking this stress response system has been proposed as a novel therapeutic strategy. In this work, we identify LiaR-independent pathways in Enterococcus faecalis that regulate cell membrane adaptation in response to antibiotics. We adapted E. faecalis OG1RF (a laboratory strain) and S613TM (a clinical strain) lacking liaR to increasing concentrations of DAP, leading to the development of DAP-R and elevated MICs to bacitracin and ceftriaxone. Whole genome sequencing identified changes in the YxdJK two-component regulatory system and a putative fatty acid kinase (dak) in both DAP-R strains. Deletion of the gene encoding the YxdJ response regulator in both the DAP-R mutant and wild-type OG1RF decreased MICs to DAP, even when a functional LiaFSR system was present. Mutations in dak were associated with slower growth, decreased membrane fluidity and alterations of cell morphology. These findings suggest that overlapping stress response pathways can provide protection against antimicrobial peptides in E. faecalis at a significant cost in bacterial fitness.
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Affiliation(s)
- William R. Miller
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Division of Infectious Diseases, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
| | - Truc T. Tran
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Division of Infectious Diseases, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
| | - Lorena Diaz
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, Bogotá, Colombia
| | - Rafael Rios
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, Bogotá, Colombia
| | - Ayesha Khan
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
| | - Jinnethe Reyes
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, Bogotá, Colombia
| | - Amy G. Prater
- Department of BioSciences, Rice University, Houston, TX, USA
| | - Diana Panesso
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Division of Infectious Diseases, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, Bogotá, Colombia
| | - Yousif Shamoo
- Department of BioSciences, Rice University, Houston, TX, USA
| | - Cesar A. Arias
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Division of Infectious Diseases, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Center for Infectious Diseases, University of Texas Health Science Center, School of Public Health, Houston, TX, USA
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, Bogotá, Colombia
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36
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Evolution and mutations predisposing to daptomycin resistance in vancomycin-resistant Enterococcus faecium ST736 strains. PLoS One 2018; 13:e0209785. [PMID: 30576392 PMCID: PMC6303062 DOI: 10.1371/journal.pone.0209785] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 12/11/2018] [Indexed: 12/16/2022] Open
Abstract
We recently identified a novel vancomycin-resistant Enterococcus faecium (VREfm) clone ST736 with reduced daptomycin susceptibility. The objectives of this study were to assess the population dynamics of local VREfm strains and genetic alterations predisposing to daptomycin resistance in VREfm ST736 strains. Multilocus sequence typing and single nucleotide variant data were derived from whole-genome sequencing of 250 E. faecium isolates from 1994–1995 (n = 43), 2009–2012 (n = 115) and 2013 (n = 92). A remarkable change was noticed in the clonality and antimicrobial resistance profiles of E. faecium strains between 1994–1995 and 2013. VREfm sequence type 17 (ST17), the prototype strain of clade A1, was the dominant clone (76.7%) recognized in 1994–1995. By contrast, clone ST736 accounted for 46.7% of VREfm isolates, followed by ST18 (26.1%) and ST412 (20.7%) in 2013. Bayesian evolutionary analysis suggested that clone ST736 emerged between 1996 and 2009. Co-mutations (liaR.W73C and liaS.T120A) of the liaFSR system were identified in all ST736 isolates (n = 111, 100%) examined. Thirty-eight (34.2%) ST736 isolates exhibited daptomycin-resistant phenotype, of which 13 isolates had mutations in both the liaFSR and cardiolipin synthase (cls) genes and showed high level of resistance with a daptomycin MIC50 of 32 μg/mL. The emergence of ST736 strains with mutations predisposing to daptomycin resistance and subsequent clonal spread among inpatients contributed to the observed high occurrence of daptomycin resistance in VREfm at our institution. The expanding geographic distribution of ST736 strains in other states and countries raises concerns about its global dissemination.
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37
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Making and Breaking of an Essential Poison: the Cyclases and Phosphodiesterases That Produce and Degrade the Essential Second Messenger Cyclic di-AMP in Bacteria. J Bacteriol 2018; 201:JB.00462-18. [PMID: 30224435 DOI: 10.1128/jb.00462-18] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cyclic di-AMP is a second-messenger nucleotide that is produced by many bacteria and some archaea. Recent work has shown that c-di-AMP is unique among the signaling nucleotides, as this molecule is in many bacteria both essential on one hand and toxic upon accumulation on the other. Moreover, in bacteria, like Bacillus subtilis, c-di-AMP controls a biological process, potassium homeostasis, by binding both potassium transporters and riboswitch molecules in the mRNAs that encode the potassium transporters. In addition to the control of potassium homeostasis, c-di-AMP has been implicated in many cellular activities, including DNA repair, cell wall homeostasis, osmotic adaptation, biofilm formation, central metabolism, and virulence. c-di-AMP is synthesized and degraded by diadenylate cyclases and phosphodiesterases, respectively. In the diadenylate cyclases, one type of catalytic domain, the diadenylate cyclase (DAC) domain, is coupled to various other domains that control the localization, the protein-protein interactions, and the regulation of the enzymes. The phosphodiesterases have a catalytic core that consists either of a DHH/DHHA1 or of an HD domain. Recent findings on the occurrence, domain organization, activity control, and structural features of diadenylate cyclases and phosphodiesterases are discussed in this review.
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38
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Davlieva M, Wu C, Zhou Y, Arias CA, Shamoo Y. Two Mutations Commonly Associated with Daptomycin Resistance in Enterococcus faecium LiaS T120A and LiaR W73C Appear To Function Epistatically in LiaFSR Signaling. Biochemistry 2018; 57:6797-6805. [PMID: 30403130 DOI: 10.1021/acs.biochem.8b01072] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The cyclic antimicrobial lipopeptide daptomycin is now frequently used as a first-line therapy in serious infections caused by multidrug-resistant Enterococcus faecium. Resistance to daptomycin in E. faecium is mediated by activation of the LiaFSR membrane stress response pathway. Deletion of liaR, encoding the response regulator of the system, restores susceptibility to daptomycin, suggesting that the LiaFSR pathway is a potential target for the development of drugs that would induce hypersusceptibility to daptomycin and make it more difficult for enterococci to become daptomycin-resistant. In clinical isolates of E. faecium, substitutions in the membrane-bound histidine kinase LiaS (T120A) and its response regulator LiaR (W73C) are found together, suggesting a potential epistatic relationship in daptomycin resistance. Using in vitro phosphorylation studies, we show that while the phosphotransfer rate of wild-type LiaS and LiaST120A to either wild-type LiaR or LiaRW73C remains rapid and comparable, the LiaS-dependent dephosphorylation rate of phosphorylated LiaRW73C is markedly higher. When the two adaptive mutants LiaRW73C and LiaST210A are paired, however, LiaS-mediated LiaR dephosphorylation is restored back to wild-type levels. Taken together with earlier work showing that LiaRW73C leads to an increased level of oligomerization and subsequently favors an increased level of transcription of the LiaFSR regulon, the net effect of the two commonly found LiaST120A and LiaRW73C alleles would be to coordinately increase the strength and persistence of LiaFSR signaling and decrease daptomycin susceptibility. The in vitro approaches developed in this work also provide the basis for screens for identifying drug candidates that inhibit the LiaFSR pathway.
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Affiliation(s)
- Milya Davlieva
- Department of Biosciences , Rice University , Houston , Texas 77005 , United States
| | - Chelsea Wu
- Department of Biosciences , Rice University , Houston , Texas 77005 , United States
| | - Yue Zhou
- Department of Biosciences , Rice University , Houston , Texas 77005 , United States
| | - Cesar A Arias
- Core for Biomolecular Structure and Function, Department of Genomic Medicine , The University of Texas M. D. Anderson Cancer Center , Houston , Texas 77054 , United States.,Center for Antimicrobial Resistance and Microbial Genomics and Division of Infectious Diseases, McGovern Medical School , The University of Texas Health Science Center at Houston , Houston , Texas 77030 , United States.,Department of Microbiology and Molecular Genetics, McGovern Medical School , The University of Texas Health Science Center at Houston , Houston , Texas 77030 , United States.,Center for Infectious Diseases, School of Public Health , The University of Texas Health Science Center at Houston , Houston , Texas 77030 , United States.,Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics , Universidad El Bosque , Bogotá 110121 , Colombia
| | - Yousif Shamoo
- Department of Biosciences , Rice University , Houston , Texas 77005 , United States
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Update on prevalence and mechanisms of resistance to linezolid, tigecycline and daptomycin in enterococci in Europe: Towards a common nomenclature. Drug Resist Updat 2018; 40:25-39. [DOI: 10.1016/j.drup.2018.10.002] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 08/10/2018] [Accepted: 10/30/2018] [Indexed: 01/04/2023]
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40
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Evolution of Antibiotic Resistance in Biofilm and Planktonic Pseudomonas aeruginosa Populations Exposed to Subinhibitory Levels of Ciprofloxacin. Antimicrob Agents Chemother 2018; 62:AAC.00320-18. [PMID: 29760140 DOI: 10.1128/aac.00320-18] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 05/01/2018] [Indexed: 11/20/2022] Open
Abstract
The opportunistic Gram-negative pathogen Pseudomonas aeruginosa, known for its intrinsic and acquired antibiotic resistance, has a notorious ability to form biofilms, which often facilitate chronic infections. The evolutionary paths to antibiotic resistance have mainly been investigated in planktonic cultures and are less studied in biofilms. We experimentally evolved P. aeruginosa PAO1 colony biofilms and stationary-phase planktonic cultures for seven passages in the presence of subinhibitory levels (0.1 mg/liter) of ciprofloxacin (CIP) and performed a genotypic (whole-bacterial population sequencing) and phenotypic assessment of the populations. We observed a higher proportion of CIP resistance in the CIP-evolved biofilm populations than in planktonic populations exposed to the same drug concentrations. However, the MICs of ciprofloxacin were lower in CIP-resistant isolates selected from the biofilm population than the MICs of CIP-resistant isolates from the planktonic cultures. We found common evolutionary trajectories between the different lineages, with mutations in known CIP resistance determinants as well as growth condition-dependent adaptations. We observed a general trend toward a reduction in type IV-pilus-dependent motility (twitching) in CIP-evolved populations and a loss of virulence-associated traits in the populations evolved in the absence of antibiotic. In conclusion, our data indicate that biofilms facilitate the development of low-level mutational resistance, probably due to the lower effective drug exposure than in planktonic cultures. These results provide a framework for the selection process of resistant variants and the evolutionary mechanisms involved under the two different growth conditions.
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41
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Pathogenic Nocardia cyriacigeorgica and Nocardia nova Evolve To Resist Trimethoprim-Sulfamethoxazole by both Expected and Unexpected Pathways. Antimicrob Agents Chemother 2018; 62:AAC.00364-18. [PMID: 29686152 DOI: 10.1128/aac.00364-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 04/15/2018] [Indexed: 12/12/2022] Open
Abstract
Nocardia spp. are Gram-positive opportunistic pathogens that affect largely immunocompromised patients, leading to serious pulmonary or systemic infections. Combination therapy using the folate biosynthesis pathway inhibitors trimethoprim (TMP) and sulfamethoxazole (SMX) is commonly used as an antimicrobial therapy. Not surprisingly, as antibiotic therapies for nocardiosis can extend for many months, resistance to TMP-SMX has emerged. Using experimental evolution, we surveyed the genetic basis of adaptation to TMP-SMX across 8 strains of Nocardia nova and 2 strains of Nocardia cyriacigeorgica By employing both continuous experimental evolution to provide longitudinal information on the order of changes and characterization of resistant endpoint isolates, we observe changes that are consistent with modifications of two enzymes of the folate biosynthesis pathway: dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) (FolP), with the mutations often being clustered near the active site of the enzymes. While changes to DHFR and DHPS might be expected, we also noted that mutations in a previously undescribed homolog of DHPS (DHPS2 or FolP2) that was annotated as being "nonfunctional" were also sufficient to generate TMP-SMX resistance, which serves as a cautionary tale for the use of automated annotation by investigators and for the future discovery of drugs against this genus. Additionally, folP2 overlapped glucosyl-3-phosphoglycerate synthase. Remarkably, an adaptive frameshift mutation within the overlapping region resulted in a new in-frame fusion to the downstream gene to produce a potentially new bifunctional enzyme. How a single potentially bifunctional DHPS2 enzyme might confer resistance is unclear. However, it highlights the unexpected ways in which adaptive evolution finds novel solutions for selection.
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Knöppel A, Knopp M, Albrecht LM, Lundin E, Lustig U, Näsvall J, Andersson DI. Genetic Adaptation to Growth Under Laboratory Conditions in Escherichia coli and Salmonella enterica. Front Microbiol 2018; 9:756. [PMID: 29755424 PMCID: PMC5933015 DOI: 10.3389/fmicb.2018.00756] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 04/04/2018] [Indexed: 11/16/2022] Open
Abstract
Experimental evolution under controlled laboratory conditions is becoming increasingly important to address various evolutionary questions, including, for example, the dynamics and mechanisms of genetic adaptation to different growth and stress conditions. In such experiments, mutations typically appear that increase the fitness under the conditions tested (medium adaptation), but that are not necessarily of interest for the specific research question. Here, we have identified mutations that appeared during serial passage of E. coli and S. enterica in four different and commonly used laboratory media and measured the relative competitive fitness and maximum growth rate of 111 genetically re-constituted strains, carrying different single and multiple mutations. Little overlap was found between the mutations that were selected in the two species and the different media, implying that adaptation occurs via different genetic pathways. Furthermore, we show that commonly occurring adaptive mutations can generate undesired genetic variation in a population and reduce the accuracy of competition experiments. However, by introducing media adaptation mutations with large effects into the parental strain that was used for the evolution experiment, the variation (standard deviation) was decreased 10-fold, and it was possible to measure fitness differences between two competitors as small as |s| < 0.001.
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Affiliation(s)
- Anna Knöppel
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Michael Knopp
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Lisa M Albrecht
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Erik Lundin
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Ulrika Lustig
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Joakim Näsvall
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Dan I Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
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Genetic Basis of Emerging Vancomycin, Linezolid, and Daptomycin Heteroresistance in a Case of Persistent Enterococcus faecium Bacteremia. Antimicrob Agents Chemother 2018; 62:AAC.02007-17. [PMID: 29339387 PMCID: PMC5913925 DOI: 10.1128/aac.02007-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/20/2017] [Indexed: 02/07/2023] Open
Abstract
Whole-genome sequencing was used to examine a persistent Enterococcus faecium bacteremia that acquired heteroresistance to three antibiotics in response to prolonged multidrug therapy. A comparison of the complete genomes before and after each change revealed the emergence of known resistance determinants for vancomycin and linezolid and suggested that a novel mutation in fabF, encoding a fatty acid synthase, was responsible for daptomycin nonsusceptibility. Plasmid recombination contributed to the progressive loss of vancomycin resistance after withdrawal of the drug.
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Reduced Chlorhexidine and Daptomycin Susceptibility in Vancomycin-Resistant Enterococcus faecium after Serial Chlorhexidine Exposure. Antimicrob Agents Chemother 2017; 62:AAC.01235-17. [PMID: 29038276 PMCID: PMC5740357 DOI: 10.1128/aac.01235-17] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 10/10/2017] [Indexed: 12/22/2022] Open
Abstract
Vancomycin-resistant Enterococcus faecium strains (VREfm) are critical public health concerns because they are among the leading causes of hospital-acquired bloodstream infections. Chlorhexidine (CHX) is a bisbiguanide cationic antiseptic that is routinely used for patient bathing and other infection control practices. VREfm are likely frequently exposed to CHX; however, the long-term effects of CHX exposure have not been studied in enterococci. In this study, we serially exposed VREfm to increasing concentrations of CHX for a period of 21 days in two independent experimental evolution trials. Reduced CHX susceptibility emerged (4-fold shift in CHX MIC). Subpopulations with reduced daptomycin (DAP) susceptibility were detected, which were further analyzed by genome sequencing and lipidomic analysis. Across the trials, we identified adaptive changes in genes with predicted or experimentally confirmed roles in chlorhexidine susceptibility (efrE), global nutritional stress response (relA), nucleotide metabolism (cmk), phosphate acquisition (phoU), and glycolipid biosynthesis (bgsB), among others. Moreover, significant alterations in membrane phospholipids were identified for some populations with reduced DAP susceptibility. Our results are clinically significant because they identify a link between serial subinhibitory CHX exposure and reduced DAP susceptibility. In addition, the CHX-induced genetic and lipidomic changes described in this study offer new insights into the mechanisms underlying the emergence of antibiotic resistance in VREfm.
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Citterio B, Pasquaroli S, Mangiaterra G, Vignaroli C, Di Sante L, Leoni F, Chierichetti S, Ottaviani D, Rocchi M, Biavasco F. Venus clam (Chamelea gallina): A reservoir of multidrug-resistant enterococci. Food Control 2017. [DOI: 10.1016/j.foodcont.2017.06.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Beabout K, McCurry MD, Mehta H, Shah AA, Pulukuri KK, Rigol S, Wang Y, Nicolaou KC, Shamoo Y. Experimental Evolution of Diverse Strains as a Method for the Determination of Biochemical Mechanisms of Action for Novel Pyrrolizidinone Antibiotics. ACS Infect Dis 2017; 3:854-865. [PMID: 28942642 DOI: 10.1021/acsinfecdis.7b00135] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The continuing rise of multidrug resistant pathogens has made it clear that in the absence of new antibiotics we are moving toward a "postantibiotic" world, in which even routine infections will become increasingly untreatable. There is a clear need for the development of new antibiotics with truly novel mechanisms of action to combat multidrug resistant pathogens. Experimental evolution to resistance can be a useful tactic for the characterization of the biochemical mechanism of action for antibiotics of interest. Herein, we demonstrate that the use of a diverse panel of strains with well-annotated reference genomes improves the success of using experimental evolution to characterize the mechanism of action of a novel pyrrolizidinone antibiotic analog. Importantly, we used experimental evolution under conditions that favor strongly polymorphic populations to adapt a panel of three substantially different Gram-positive species (lab strain Bacillus subtilis and clinical strains methicillin-resistant Staphylococcus aureus MRSA131 and Enterococcus faecalis S613) to produce a sufficiently diverse set of evolutionary outcomes. Comparative whole genome sequencing (WGS) between the susceptible starting strain and the resistant strains was then used to identify the genetic changes within each species in response to the pyrrolizidinone. Taken together, the adaptive response across a range of organisms allowed us to develop a readily testable hypothesis for the mechanism of action of the CJ-16 264 analog. In conjunction with mitochondrial inhibition studies, we were able to elucidate that this novel pyrrolizidinone antibiotic is an electron transport chain (ETC) inhibitor. By studying evolution to resistance in a panel of different species of bacteria, we have developed an enhanced method for the characterization of new lead compounds for the discovery of new mechanisms of action.
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Affiliation(s)
- Kathryn Beabout
- Department
of BioSciences, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Megan D. McCurry
- Department
of BioSciences, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Heer Mehta
- Department
of BioSciences, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Akshay A. Shah
- Department
of Chemistry, BioScience Research Collaborative, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Kiran Kumar Pulukuri
- Department
of Chemistry, BioScience Research Collaborative, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Stephan Rigol
- Department
of Chemistry, BioScience Research Collaborative, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Yanping Wang
- Department
of Chemistry, BioScience Research Collaborative, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - K. C. Nicolaou
- Department
of Chemistry, BioScience Research Collaborative, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Yousif Shamoo
- Department
of BioSciences, Rice University, 6100 Main Street, Houston, Texas 77005, United States
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Higgins SA, Savage DF. Protein Science by DNA Sequencing: How Advances in Molecular Biology Are Accelerating Biochemistry. Biochemistry 2017; 57:38-46. [DOI: 10.1021/acs.biochem.7b00886] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Sean A. Higgins
- Department
of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, United States
| | - David F. Savage
- Department
of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, United States
- Department
of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
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A Delicate Connection: c-di-AMP Affects Cell Integrity by Controlling Osmolyte Transport. Trends Microbiol 2017; 26:175-185. [PMID: 28965724 DOI: 10.1016/j.tim.2017.09.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 08/16/2017] [Accepted: 09/08/2017] [Indexed: 12/15/2022]
Abstract
Bacteria use second-messenger molecules to adapt to their environment. Several second messengers, among them cyclic di-AMP (c-di-AMP), have been discovered and intensively studied. Interestingly, c-di-AMP is essential for growth of Gram-positive bacteria such as Bacillus subtilis, Listeria monocytogenes, and Staphylococcus aureus. Many studies demonstrated that perturbation of c-di-AMP metabolism affects the integrity of the bacterial cell envelope. Therefore, it has been assumed that the nucleotide is essential for proper cell envelope synthesis. In this Opinion paper, we propose that the cell envelope phenotypes caused by perturbations of c-di-AMP metabolism can be interpreted differently: c-di-AMP might indirectly control cell envelope integrity by modulating the turgor, a physical variable that needs to be tightly adjusted. We also discuss open questions related to c-di-AMP metabolism that need to be urgently addressed by future studies.
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Using experimental evolution to identify druggable targets that could inhibit the evolution of antimicrobial resistance. J Antibiot (Tokyo) 2017; 71:279-286. [PMID: 28928474 PMCID: PMC5788704 DOI: 10.1038/ja.2017.108] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/27/2017] [Accepted: 08/05/2017] [Indexed: 02/05/2023]
Abstract
With multi-drug and pan-drug-resistant bacteria becoming increasingly common in hospitals, antibiotic resistance has threatened to return us to a pre-antibiotic era that would completely undermine modern medicine. There is an urgent need to develop new antibiotics and strategies to combat resistance that are substantially different from earlier drug discovery efforts. One such strategy that would complement current and future antibiotics would be a class of co-drugs that target the evolution of resistance and thereby extend the efficacy of specific classes of antibiotics. A critical step in the development of such strategies lies in understanding the critical evolutionary trajectories responsible for resistance and which proteins or biochemical pathways within those trajectories would be good candidates for co-drug discovery. We identify the most important steps in the evolution of resistance for a specific pathogen and antibiotic combination by evolving highly polymorphic populations of pathogens to resistance in a novel bioreactor that favors biofilm development. As the populations evolve to increasing drug concentrations, we use deep sequencing to elucidate the network of genetic changes responsible for resistance and subsequent in vitro biochemistry and often structure determination to determine how the adaptive mutations produce resistance. Importantly, the identification of the molecular steps, their frequency within the populations and their chronology within the evolutionary trajectory toward resistance is critical to assessing their relative importance. In this work, we discuss findings from the evolution of the ESKAPE pathogen, Pseudomonas aeruginosa to the drug of last resort, colistin to illustrate the power of this approach.
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Miller WR, Murray BE, Rice LB, Arias CA. Vancomycin-Resistant Enterococci: Therapeutic Challenges in the 21st Century. Infect Dis Clin North Am 2017; 30:415-439. [PMID: 27208766 DOI: 10.1016/j.idc.2016.02.006] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Vancomycin-resistant enterococci are serious health threats due in part to their ability to persist in rugged environments and their propensity to acquire antibiotic resistance determinants. Enterococci have now established a home in our hospitals and possess mechanisms to defeat most currently available antimicrobials. This article reviews the history of the struggle with this pathogen, what is known about the traits associated with its rise in the modern medical environment, and the current understanding of therapeutic approaches in severe infections caused by these microorganisms. As the 21st century progresses, vancomycin-resistant enterococci continue to pose a daunting clinical challenge.
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Affiliation(s)
- William R Miller
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, TX 77030, USA
| | - Barbara E Murray
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, TX 77030, USA; Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, TX 77030, USA
| | - Louis B Rice
- Departments of Medicine, Microbiology and Immunology, Warren Alpert Medical School of Brown University, 593 Eddy Street, Providence, RI 02903, USA
| | - Cesar A Arias
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, TX 77030, USA; Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, TX 77030, USA; Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, Avenue Cra 9 No. 131 A - 02, Bogotá, Colombia.
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