151
|
Active efflux in dormant bacterial cells - New insights into antibiotic persistence. Drug Resist Updat 2016; 30:7-14. [PMID: 28363336 DOI: 10.1016/j.drup.2016.11.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 10/14/2016] [Accepted: 11/02/2016] [Indexed: 01/07/2023]
Abstract
Bacterial persisters are phenotypic variants of an isogenic cell population that can survive antibiotic treatment and resume growth after the antibiotics have been removed. Cell dormancy has long been considered the principle mechanism underlying persister formation. However, dormancy alone is insufficient to explain the full range of bacterial persistence. Our recent work revealed that in addition to 'passive defense' via dormancy, persister cells employ 'active defense' via enhanced efflux activity to expel drugs. This finding suggests that persisters combine two seemingly contradictory mechanisms to tolerate antibiotic attack. Here, we review the passive and active aspects of persister formation, discuss new insights into the process, and propose new techniques that can facilitate the study of bacterial persistence.
Collapse
|
152
|
Yang Y, Huang Z, Zou X, Zhong X, Liang X, Zhou J. THE ANTIBACTERIAL EFFECT OF URENA LOBATA L. FROMV GUANGXI ON MICE WITH STAPHYLOCOCCUS AUREUS PNEUMONIA. AFRICAN JOURNAL OF TRADITIONAL, COMPLEMENTARY, AND ALTERNATIVE MEDICINES 2016; 14:73-88. [PMID: 28480385 PMCID: PMC5411887 DOI: 10.21010/ajtcam.v14i1.9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background: Alcohol extract from the root of Urena lobata L. (ULL) had broad spectrum antimicrobial activity. Studies in vitro have sho that ULL aqueous extract has antibacterial effect on S. aureusis, and the combination therapy of the ULL aqueous extract with cefazolin sodium showed additive effect. Materials and Methods: The mice underwent nasal inhalation with S. aureus, a subset of mice were intra-gastric gavage with ULL and/or intravenous injection cefazolin sodium twice daily. After being exposed to S. aureus for 5 days, 10 days and 14 days respectively, the white blood cells count (WBC), neutrophils absolute value (NEU) and the neutrophil percentage (NEU%) in peripheral blood, as well as the levels of serum immunoglobulin (Ig) G and IgM were determined using commercial kits. The colony count of S. aureus, the levels of interleukin (IL) -6 and IL-10 of mice lung tissue were detected, and the pathological changes of lung tissue were examined using H & E staining. Results: ULL significantly protected against S. aureus pneumonia, as evidenced by the remarkable decrease in the rate of S. aureus colony count/lung weight, WBC, NEU and NEU% in peripheral blood, as well as the attenuation of lung histopathological damage. Additionally, ULL+cefazolin could have markedly reduced the rate of S. aureus colony count/lung weight when compared with cefazolin. Furthermore, ULL and ULL+cefazolin both could significantly decrease the serum levels of IgG and IgM, and the levels of IL-6, IL-10 in mice lung tissue. Conclusion: This study first demonstrated that ULL may have potential use as a therapeutic agent for S. aureus pneumonia, and the roles of IgG, IgM, IL-6 and IL-10 in ULL protection against S. aureus pneumonia remain to be further studied.
Collapse
Affiliation(s)
- Yufang Yang
- Department of Pharmacy, The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China
| | - Zhenguang Huang
- Department of Pharmacy, The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China
| | - Xiaoqin Zou
- Department of Pharmacy, The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China
| | - Xiaobin Zhong
- Regenerative medicine research center of Guangxi Medical University. Post Graduate Students
| | - Xueyan Liang
- Regenerative medicine research center of Guangxi Medical University. Post Graduate Students
| | - Jinling Zhou
- Regenerative medicine research center of Guangxi Medical University. Post Graduate Students
| |
Collapse
|
153
|
Toth Hervay N, Konecna A, Balazfyova Z, Svrbicka A, Gbelska Y. Insight into the Kluyveromyces lactis Pdr1p regulon. Can J Microbiol 2016; 62:918-931. [PMID: 27556366 DOI: 10.1139/cjm-2016-0220] [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: 11/22/2022]
Abstract
The overexpression of efflux pumps is an important mechanism leading to the development of multidrug resistance phenomenon. The transcription factor KlPdr1p, belonging to the Zn2Cys6 family, is a central regulator of efflux pump expression in Kluyveromyces lactis. To better understand how KlPDR1-mediated drug resistance is achieved in K. lactis, we used DNA microarrays to identify genes whose expression was affected by deletion or overexpression of the KlPDR1 gene. Eighty-nine targets of the KlPDR1 were identified. From those the transcription of 16 genes was induced in the transformant overexpressing KlPDR1* and simultaneously repressed in the Klpdr1Δ deletion mutant. Almost all of these genes contain putative binding motifs for the AP-1-like transcription factors in their promoters. Furthermore, we studied the possible interplay between KlPdr1p and KlYap1p transcription factors. Our results show that KlYap1p does not significantly contribute to the regulation of KlPDR1 gene expression in the presence of azoles. However, KlPDR1 expression markedly increased in the presence of hydrogen peroxide and hinged upon the presence of KlYap1p. Our results show that although both KlPdr1p and KlYap1p transcription factors are involved in the control of K. lactis multidrug resistance, further studies will be needed to determine their interplay.
Collapse
Affiliation(s)
- Nora Toth Hervay
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
| | - Alexandra Konecna
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
| | - Zuzana Balazfyova
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
| | - Alexandra Svrbicka
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
| | - Yvetta Gbelska
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
| |
Collapse
|
154
|
Palma TH, Harth-Chú EN, Scott J, Stipp RN, Boisvert H, Salomão MF, Theobaldo JD, Possobon RF, Nascimento LC, McCafferty JW, Faller L, Duncan MJ, Mattos-Graner RO. Oral cavities of healthy infants harbour high proportions of Streptococcus salivarius strains with phenotypic and genotypic resistance to multiple classes of antibiotics. J Med Microbiol 2016; 65:1456-1464. [PMID: 27902365 DOI: 10.1099/jmm.0.000377] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Emerging antibiotic resistance in the oropharyngeal microbiota, of which Streptococcus salivarius is a prominent species, represents a challenge for treating paediatric populations. In this study, we investigated the role of Streptococcussalivarius as a reservoir for antibiotic resistance genes (ARG) in the oral microbiota by analysing 95 Streptococcussalivarius isolates from 22 healthy infants (2-16 months of age). MICs of penicillin G, amoxicillin, erythromycin, tetracycline, doxycycline and streptomycin were determined. ARG profiles were assessed in a subset of 21 strains by next-generation sequencing of genomes, followed by searches of assembled reads against the Comprehensive Antibiotic Resistance Database. Strains resistant to erythromycin, penicillins and tetracyclines were isolated from 83.3, 33.3 and 16.6 %, respectively, of infants aged 2 to 8 months with no prior antibiotic treatment. These percentages were100.0, 66.6 and 50.0 %, by 13 to 16 months of age. ARG or polymorphisms associated with antibiotic resistance were the most prevalent and involved genes for macrolide efflux (mel, mefA/E and macB), ribosomal protection [erm(B), tet(M) and tet(O)] and β-lactamase-like proteins. Phylogenetically related strains showing multidrug-resistant phenotypes harboured multidrug efflux ARG. Polymorphic genes associated with antibiotic resistance to drugs affecting DNA replication, folate synthesis, RNA/protein synthesis and regulators of antibiotic stress responses were detected. These data imply that Streptococcussalivarius strains established during maturation of the oral microbiota harbour a diverse array of functional ARG, even in the absence of antibiotic selective pressures, highlighting a potential role for this species in shaping antibiotic susceptibility profiles of oropharyngeal communities.
Collapse
Affiliation(s)
- Thaís H Palma
- Department of Oral Diagnosis, University of Campinas, São Paulo, Brazil
| | - Erika N Harth-Chú
- Department of Oral Diagnosis, University of Campinas, São Paulo, Brazil
| | - Jodie Scott
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
| | - Rafael N Stipp
- Department of Oral Diagnosis, University of Campinas, São Paulo, Brazil
| | - Heike Boisvert
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
| | | | | | - Rosana F Possobon
- Cepae - Research and Dental Care Center for Special Needs Patients of Piracicaba Dental School, University of Campinas, São Paulo, Brazil
| | - Leandro C Nascimento
- Laboratory of Genomics and Gene Expression (LGE), University of Campinas, São Paulo, Brazil
| | | | - Lina Faller
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
| | - Margaret J Duncan
- Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA
| | | |
Collapse
|
155
|
Phetsang W, Pelingon R, Butler MS, KC S, Pitt ME, Kaeslin G, Cooper MA, Blaskovich MAT. Fluorescent Trimethoprim Conjugate Probes To Assess Drug Accumulation in Wild Type and Mutant Escherichia coli. ACS Infect Dis 2016; 2:688-701. [PMID: 27737551 PMCID: PMC5067704 DOI: 10.1021/acsinfecdis.6b00080] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
![]()
Reduced
susceptibility to antimicrobials in Gram-negative bacteria may result
from multiple resistance mechanisms, including increased efflux pump
activity or reduced porin protein expression. Up-regulation of the
efflux pump system is closely associated with multidrug resistance
(MDR). To help investigate the role of efflux pumps on compound accumulation,
a fluorescence-based assay was developed using fluorescent derivatives
of trimethoprim (TMP), a broad-spectrum synthetic antibiotic that
inhibits an intracellular target, dihydrofolate reductase (DHFR).
Novel fluorescent TMP probes inhibited eDHFR activity
with comparable potency to TMP, but did not kill or inhibit growth
of wild type Escherichia coli. However,
bactericidal activity was observed against an efflux pump deficient E. coli mutant strain (ΔtolC). A simple and quick fluorescence assay was developed to measure
cellular accumulation of the TMP probe using either fluorescence spectroscopy
or flow cytometry, with validation by LC-MS/MS. This fluorescence
assay may provide a simple method to assess efflux pump activity with
standard laboratory equipment.
Collapse
Affiliation(s)
- Wanida Phetsang
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Ruby Pelingon
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Mark S. Butler
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Sanjaya KC
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Miranda E. Pitt
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Geraldine Kaeslin
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Matthew A. Cooper
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Mark A. T. Blaskovich
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| |
Collapse
|
156
|
Bansal S, Bajaj P, Pandey S, Tandon V. Topoisomerases: Resistance versus Sensitivity, How Far We Can Go? Med Res Rev 2016; 37:404-438. [PMID: 27687257 DOI: 10.1002/med.21417] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 08/04/2016] [Accepted: 08/29/2016] [Indexed: 12/15/2022]
Abstract
DNA topoisomerases are ubiquitously present remarkable molecular machines that help in altering topology of DNA in living cells. The crucial role played by these nucleases during DNA replication, transcription, and recombination vis-à-vis less sequence similarity among different species makes topoisomerases unique and attractive targets for different anticancer and antibacterial drugs. However, druggability of topoisomerases by the existing class of molecules is increasingly becoming questationable due to resistance development predominated by mutations in the corresponding genes. The current scenario facing a decline in the development of new molecules further comprises an important factor that may challenge topoisomerase-targeting therapy. Thus, it is imperative to wisely use the existing inhibitors lest with this rapid rate of losing grip over the target we may not go too far. Furthermore, it is important not only to design new molecules but also to develop new approaches that may avoid obstacles in therapies due to multiple resistance mechanisms. This review provides a succinct account of different classes of topoisomerase inhibitors, focuses on resistance acquired by mutations in topoisomerases, and discusses the various approaches to increase the efficacy of topoisomerase inhibitors. In a later section, we also suggest the possibility of using bisbenzimidazoles along with efflux pump inhibitors for synergistic bactericidal effects.
Collapse
Affiliation(s)
- Sandhya Bansal
- Dr. B.R. Ambedkar Center for Biomedical Research, University of Delhi, New Delhi, India
| | - Priyanka Bajaj
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Stuti Pandey
- Department of Chemistry, University of Delhi, New Delhi, India
| | - Vibha Tandon
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India.,Department of Chemistry, University of Delhi, New Delhi, India
| |
Collapse
|
157
|
Hu Q, Zhang XX, Jia S, Huang K, Tang J, Shi P, Ye L, Ren H. Metagenomic insights into ultraviolet disinfection effects on antibiotic resistome in biologically treated wastewater. WATER RESEARCH 2016; 101:309-317. [PMID: 27267479 DOI: 10.1016/j.watres.2016.05.092] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 05/14/2016] [Accepted: 05/29/2016] [Indexed: 05/08/2023]
Abstract
High-throughput sequencing-based metagenomic approaches were used to comprehensively investigate ultraviolet effects on the microbial community structure, and diversity and abundance of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) in biologically treated wastewater. After ultraviolet radiation, some dominant genera, like Aeromonas and Halomonas, in the wastewater almost disappeared, while the relative abundance of some minor genera including Pseudomonas and Bacillus increased dozens of times. Metagenomic analysis showed that 159 ARGs within 14 types were detectable in the samples, and the radiation at 500 mJ/cm(2) obviously increased their total relative abundance from 31.68 ppm to 190.78 ppm, which was supported by quantitative real time PCR. As the dominant persistent ARGs, multidrug resistance genes carried by Pseudomonas and bacitracin resistance gene bacA carried by Bacillus mainly contributed to the ARGs abundance increase. Bacterial community shift and MGEs replication induced by the radiation might drive the resistome alteration. The findings may shed new light on the mechanism behind the ultraviolet radiation effects on antibiotic resistance in wastewater.
Collapse
Affiliation(s)
- Qing Hu
- State Key Laboratory of Pollution Control and Resource Reuse, Environmental Health Research Center, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Xu-Xiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, Environmental Health Research Center, School of the Environment, Nanjing University, Nanjing 210023, China.
| | - Shuyu Jia
- State Key Laboratory of Pollution Control and Resource Reuse, Environmental Health Research Center, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Kailong Huang
- State Key Laboratory of Pollution Control and Resource Reuse, Environmental Health Research Center, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Junying Tang
- State Key Laboratory of Pollution Control and Resource Reuse, Environmental Health Research Center, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Peng Shi
- State Key Laboratory of Pollution Control and Resource Reuse, Environmental Health Research Center, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Lin Ye
- State Key Laboratory of Pollution Control and Resource Reuse, Environmental Health Research Center, School of the Environment, Nanjing University, Nanjing 210023, China.
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, Environmental Health Research Center, School of the Environment, Nanjing University, Nanjing 210023, China
| |
Collapse
|
158
|
Genome-based insights into the resistome and mobilome of multidrug-resistant Aeromonas sp. ARM81 isolated from wastewater. Arch Microbiol 2016; 199:177-183. [PMID: 27590015 PMCID: PMC5216076 DOI: 10.1007/s00203-016-1285-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/20/2016] [Accepted: 08/27/2016] [Indexed: 11/26/2022]
Abstract
The draft genome of multidrug-resistant Aeromonas sp. ARM81 isolated from a wastewater treatment plant in Warsaw (Poland) was obtained. Sequence analysis revealed multiple genes conferring resistance to aminoglycosides, β-lactams or tetracycline. Three different β-lactamase genes were identified, including an extended-spectrum β-lactamase gene blaPER-1. The antibiotic susceptibility was experimentally tested. Genome sequencing also allowed us to investigate the plasmidome and transposable mobilome of ARM81. Four plasmids, of which two carry phenotypic modules (i.e., genes encoding a zinc transporter ZitB and a putative glucosyltransferase), and 28 putative transposase genes were identified. The mobility of three insertion sequences (isoforms of previously identified elements ISAs12, ISKpn9 and ISAs26) was confirmed using trap plasmids.
Collapse
|
159
|
Hooper DC, Jacoby GA. Topoisomerase Inhibitors: Fluoroquinolone Mechanisms of Action and Resistance. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a025320. [PMID: 27449972 DOI: 10.1101/cshperspect.a025320] [Citation(s) in RCA: 255] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Quinolone antimicrobials are widely used in clinical medicine and are the only current class of agents that directly inhibit bacterial DNA synthesis. Quinolones dually target DNA gyrase and topoisomerase IV binding to specific domains and conformations so as to block DNA strand passage catalysis and stabilize DNA-enzyme complexes that block the DNA replication apparatus and generate double breaks in DNA that underlie their bactericidal activity. Resistance has emerged with clinical use of these agents and is common in some bacterial pathogens. Mechanisms of resistance include mutational alterations in drug target affinity and efflux pump expression and acquisition of resistance-conferring genes. Resistance mutations in one or both of the two drug target enzymes are commonly in a localized domain of the GyrA and ParC subunits of gyrase and topoisomerase IV, respectively, and reduce drug binding to the enzyme-DNA complex. Other resistance mutations occur in regulatory genes that control the expression of native efflux pumps localized in the bacterial membrane(s). These pumps have broad substrate profiles that include other antimicrobials as well as quinolones. Mutations of both types can accumulate with selection pressure and produce highly resistant strains. Resistance genes acquired on plasmids confer low-level resistance that promotes the selection of mutational high-level resistance. Plasmid-encoded resistance is because of Qnr proteins that protect the target enzymes from quinolone action, a mutant aminoglycoside-modifying enzyme that also modifies certain quinolones, and mobile efflux pumps. Plasmids with these mechanisms often encode additional antimicrobial resistances and can transfer multidrug resistance that includes quinolones.
Collapse
Affiliation(s)
- David C Hooper
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts 02114
| | - George A Jacoby
- Lahey Hospital and Medical Center, Burlington, Massachusetts 01805
| |
Collapse
|
160
|
Techaruvichit P, Takahashi H, Kuda T, Miya S, Keeratipibul S, Kimura B. Adaptation of Campylobacter jejuni to biocides used in the food industry affects biofilm structure, adhesion strength, and cross-resistance to clinical antimicrobial compounds. BIOFOULING 2016; 32:827-839. [PMID: 27353218 DOI: 10.1080/08927014.2016.1198476] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 05/28/2016] [Indexed: 06/06/2023]
Abstract
The emergence of biocide-adapted Campylobacter jejuni strains that developed into biofilms and their potential to develop clinical resistance to antimicrobial compounds was studied. C. jejuni was grown in sub-lethal concentrations of five biocides used in the food industry. C. jejuni exhibited adaptation to these biocides with increased minimum inhibitory concentrations. The 3-D structures of the biofilms produced by the biocide-adapted cells were investigated by atomic force microscopy (AFM). The results revealed marked variability in biofilm architecture, including ice-crystal-like structures. Adaptation to the biocides enhanced biofilm formation, with significant increases in biovolume, surface coverage, roughness, and the surface adhesion force of the biofilms. Adaptation to commercial biocides induced resistance to kanamycin and streptomycin. This study suggests that the inappropriate use of biocides may lead to cells being exposed to them at sub-lethal concentrations, which can result in adaptation of the pathogens to the biocides and a subsequent risk to public health.
Collapse
Affiliation(s)
- Punnida Techaruvichit
- a Department of Food Science and Technology, Faculty of Marine Science , Tokyo University of Marine Science and Technology , Tokyo , Japan
| | - Hajime Takahashi
- a Department of Food Science and Technology, Faculty of Marine Science , Tokyo University of Marine Science and Technology , Tokyo , Japan
| | - Takashi Kuda
- a Department of Food Science and Technology, Faculty of Marine Science , Tokyo University of Marine Science and Technology , Tokyo , Japan
| | - Satoko Miya
- a Department of Food Science and Technology, Faculty of Marine Science , Tokyo University of Marine Science and Technology , Tokyo , Japan
| | - Suwimon Keeratipibul
- b Department of Food Technology, Faculty of Science , Chulalongkorn University , Bangkok , Thailand
- c Molecular Sensory Science Center, Faculty of Science , Chulalongkorn University , Bangkok , Thailand
| | - Bon Kimura
- a Department of Food Science and Technology, Faculty of Marine Science , Tokyo University of Marine Science and Technology , Tokyo , Japan
| |
Collapse
|
161
|
Ababou A, Koronakis V. Structures of Gate Loop Variants of the AcrB Drug Efflux Pump Bound by Erythromycin Substrate. PLoS One 2016; 11:e0159154. [PMID: 27403665 PMCID: PMC4942123 DOI: 10.1371/journal.pone.0159154] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 06/28/2016] [Indexed: 11/18/2022] Open
Abstract
Gram-negative bacteria such as E. coli use tripartite efflux pumps such as AcrAB-TolC to expel antibiotics and noxious compounds. A key feature of the inner membrane transporter component, AcrB, is a short stretch of residues known as the gate/switch loop that divides the proximal and distal substrate binding pockets. Amino acid substitutions of the gate loop are known to decrease antibiotic resistance conferred by AcrB. Here we present two new AcrB gate loop variants, the first stripped of its bulky side chains, and a second in which the gate loop is removed entirely. By determining the crystal structures of the variant AcrB proteins in the presence and absence of erythromycin and assessing their ability to confer erythromycin tolerance, we demonstrate that the gate loop is important for AcrB export activity but is not required for erythromycin binding.
Collapse
Affiliation(s)
- Abdessamad Ababou
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, United Kingdom
- * E-mail: (AA); (VK)
| | - Vassilis Koronakis
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, United Kingdom
- * E-mail: (AA); (VK)
| |
Collapse
|
162
|
Involvement of Antibiotic Efflux Machinery in Glutathione-Mediated Decreased Ciprofloxacin Activity in Escherichia coli. Antimicrob Agents Chemother 2016; 60:4369-74. [PMID: 27139480 DOI: 10.1128/aac.00414-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 04/24/2016] [Indexed: 01/20/2023] Open
Abstract
We have analyzed the contribution of different efflux components to glutathione-mediated abrogation of ciprofloxacin's activity in Escherichia coli and the underlying potential mechanism(s) behind this phenomenon. The results indicated that glutathione increased the total active efflux, thereby partially contributing to glutathione-mediated neutralization of ciprofloxacin's antibacterial action in E. coli However, the role of glutathione-mediated increased efflux becomes evident in the absence of a functional TolC-AcrAB efflux pump.
Collapse
|
163
|
The analysis of the antibiotic resistome offers new opportunities for therapeutic intervention. Future Med Chem 2016; 8:1133-51. [DOI: 10.4155/fmc-2016-0027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Most efforts in the development of antimicrobials have focused on the screening of lethal targets. Nevertheless, the constant expansion of antimicrobial resistance makes the antibiotic resistance determinants themselves suitable targets for finding inhibitors to be used in combination with antibiotics. Among them, inhibitors of antibiotic inactivating enzymes and of multidrug efflux pumps are suitable candidates for improving the efficacy of antibiotics. In addition, the application of systems biology tools is helping to understand the changes in bacterial physiology associated to the acquisition of resistance, including the increased susceptibility to other antibiotics displayed by some antibiotic-resistant mutants. This information is useful for implementing novel strategies based in metabolic interventions or combination of antibiotics for improving the efficacy of antibacterial therapy.
Collapse
|
164
|
Jin X, Shao Y, Bai Q, Xue W, Liu H, Yao X. Insights into conformational regulation of PfMATE transporter from Pyrococcus furiosus induced by alternating protonation state of Asp41 residue: A molecular dynamics simulation study. Biochim Biophys Acta Gen Subj 2016; 1860:1173-80. [DOI: 10.1016/j.bbagen.2016.02.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 02/03/2016] [Accepted: 02/11/2016] [Indexed: 01/01/2023]
|
165
|
Gerits E, Blommaert E, Lippell A, O’Neill AJ, Weytjens B, De Maeyer D, Fierro AC, Marchal K, Marchand A, Chaltin P, Spincemaille P, De Brucker K, Thevissen K, Cammue BPA, Swings T, Liebens V, Fauvart M, Verstraeten N, Michiels J. Elucidation of the Mode of Action of a New Antibacterial Compound Active against Staphylococcus aureus and Pseudomonas aeruginosa. PLoS One 2016; 11:e0155139. [PMID: 27167126 PMCID: PMC4864301 DOI: 10.1371/journal.pone.0155139] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 04/25/2016] [Indexed: 01/29/2023] Open
Abstract
Nosocomial and community-acquired infections caused by multidrug resistant bacteria represent a major human health problem. Thus, there is an urgent need for the development of antibiotics with new modes of action. In this study, we investigated the antibacterial characteristics and mode of action of a new antimicrobial compound, SPI031 (N-alkylated 3, 6-dihalogenocarbazol 1-(sec-butylamino)-3-(3,6-dichloro-9H-carbazol-9-yl)propan-2-ol), which was previously identified in our group. This compound exhibits broad-spectrum antibacterial activity, including activity against the human pathogens Staphylococcus aureus and Pseudomonas aeruginosa. We found that SPI031 has rapid bactericidal activity (7-log reduction within 30 min at 4x MIC) and that the frequency of resistance development against SPI031 is low. To elucidate the mode of action of SPI031, we performed a macromolecular synthesis assay, which showed that SPI031 causes non-specific inhibition of macromolecular biosynthesis pathways. Liposome leakage and membrane permeability studies revealed that SPI031 rapidly exerts membrane damage, which is likely the primary cause of its antibacterial activity. These findings were supported by a mutational analysis of SPI031-resistant mutants, a transcriptome analysis and the identification of transposon mutants with altered sensitivity to the compound. In conclusion, our results show that SPI031 exerts its antimicrobial activity by causing membrane damage, making it an interesting starting point for the development of new antibacterial therapies.
Collapse
Affiliation(s)
- Evelien Gerits
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
| | - Eline Blommaert
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
| | - Anna Lippell
- School of Molecular and Cellular Biology, University of Leeds, Leeds, United Kingdom
| | - Alex J. O’Neill
- School of Molecular and Cellular Biology, University of Leeds, Leeds, United Kingdom
| | - Bram Weytjens
- Department of Information Technology (INTEC, iMINDS), U.Ghent, Ghent, Belgium
| | - Dries De Maeyer
- Department of Information Technology (INTEC, iMINDS), U.Ghent, Ghent, Belgium
| | - Ana Carolina Fierro
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
- Department of Information Technology (INTEC, iMINDS), U.Ghent, Ghent, Belgium
| | - Kathleen Marchal
- Department of Information Technology (INTEC, iMINDS), U.Ghent, Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, U.Ghent, Ghent, Belgium
| | - Arnaud Marchand
- CISTIM Leuven vzw, Bio-Incubator, KU Leuven, Leuven, Belgium
| | - Patrick Chaltin
- CISTIM Leuven vzw, Bio-Incubator, KU Leuven, Leuven, Belgium
- Centre for Drug Design and Discovery (CD3), Research and Development, KU Leuven, Leuven, Belgium
| | - Pieter Spincemaille
- Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium
| | | | - Karin Thevissen
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
| | - Bruno P. A. Cammue
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
- Department of Plant Systems Biology, VIB, Ghent, Belgium
| | - Toon Swings
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
| | - Veerle Liebens
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
| | - Maarten Fauvart
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
- imec, Smart Systems and Emerging Technologies Unit, Department of Life Science Technologies, Leuven, Belgium
| | | | - Jan Michiels
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
- * E-mail:
| |
Collapse
|
166
|
Mechanisms of Antimicrobial Resistance in ESKAPE Pathogens. BIOMED RESEARCH INTERNATIONAL 2016; 2016:2475067. [PMID: 27274985 PMCID: PMC4871955 DOI: 10.1155/2016/2475067] [Citation(s) in RCA: 815] [Impact Index Per Article: 101.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 02/23/2016] [Accepted: 04/17/2016] [Indexed: 11/18/2022]
Abstract
The ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are the leading cause of nosocomial infections throughout the world. Most of them are multidrug resistant isolates, which is one of the greatest challenges in clinical practice. Multidrug resistance is amongst the top three threats to global public health and is usually caused by excessive drug usage or prescription, inappropriate use of antimicrobials, and substandard pharmaceuticals. Understanding the resistance mechanisms of these bacteria is crucial for the development of novel antimicrobial agents or other alternative tools to combat these public health challenges. Greater mechanistic understanding would also aid in the prediction of underlying or even unknown mechanisms of resistance, which could be applied to other emerging multidrug resistant pathogens. In this review, we summarize the known antimicrobial resistance mechanisms of ESKAPE pathogens.
Collapse
|
167
|
de Araújo RSA, Barbosa-Filho JM, Scotti MT, Scotti L, da Cruz RMD, Falcão-Silva VDS, de Siqueira-Júnior JP, Mendonça-Junior FJB. Modulation of Drug Resistance in Staphylococcus aureus with Coumarin Derivatives. SCIENTIFICA 2016; 2016:6894758. [PMID: 27200211 PMCID: PMC4856757 DOI: 10.1155/2016/6894758] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 04/03/2016] [Indexed: 06/05/2023]
Abstract
Semisynthetic and commercial coumarins were investigated for their antibacterial and adjuvant properties with antibiotic agents against norfloxacin, erythromycin, and tetracycline resistant Staphylococcus aureus as based on efflux mechanisms. The coumarins and certain commercial antibiotics had their Minimum Inhibitory Concentrations determined by broth microdilution assay against resistant S. aureus strains which overexpress efflux pump proteins. For evaluation of the modulatory activity, the antibiotics MICs were determined in the presence of the coumarin derivatives at subinhibitory concentration. Although the coumarins did not display relevant antibacterial activity (MIC ≥ 128 µg/mL), they did modulate the antibiotics activities. Various coumarins, especially the alkylated derivatives in combination with antibiotics at subinhibitory concentrations, modulated antibiotic activity, reducing the MIC for tetracycline and norfloxacin by 2 to 8 times. Polar Surface Area (PSA) studies were performed and the fact that the presence of apolar groups is an important factor for the modulatory activity of coumarins was corroborated. Docking on the Penicillin-Binding Protein from MRSA identified that 18 is a potential ligand presenting low E binding. The results indicate that coumarin derivatives modulated antibiotic resistance and may be used as potential antibiotic adjuvants, acting by bacterial efflux pump inhibition in S. aureus.
Collapse
Affiliation(s)
- Rodrigo Santos Aquino de Araújo
- Post-Graduate Program in Natural and Synthetic Bioactive Products, Federal University of Paraíba, 58051-900 João Pessoa, PB, Brazil
| | - José Maria Barbosa-Filho
- Post-Graduate Program in Natural and Synthetic Bioactive Products, Federal University of Paraíba, 58051-900 João Pessoa, PB, Brazil
| | - Marcus Tullius Scotti
- Post-Graduate Program in Natural and Synthetic Bioactive Products, Federal University of Paraíba, 58051-900 João Pessoa, PB, Brazil
| | - Luciana Scotti
- Post-Graduate Program in Natural and Synthetic Bioactive Products, Federal University of Paraíba, 58051-900 João Pessoa, PB, Brazil
| | - Ryldene Marques Duarte da Cruz
- Laboratory of Genetics of Microorganisms, Molecular Biology Department, Federal University of Paraíba, 58051-900 João Pessoa, PB, Brazil
| | - Vivyanne dos Santos Falcão-Silva
- Post-Graduate Program in Natural and Synthetic Bioactive Products, Federal University of Paraíba, 58051-900 João Pessoa, PB, Brazil
- Laboratory of Genetics of Microorganisms, Molecular Biology Department, Federal University of Paraíba, 58051-900 João Pessoa, PB, Brazil
| | - José Pinto de Siqueira-Júnior
- Post-Graduate Program in Natural and Synthetic Bioactive Products, Federal University of Paraíba, 58051-900 João Pessoa, PB, Brazil
- Laboratory of Genetics of Microorganisms, Molecular Biology Department, Federal University of Paraíba, 58051-900 João Pessoa, PB, Brazil
| | - Francisco Jaime Bezerra Mendonça-Junior
- Post-Graduate Program in Natural and Synthetic Bioactive Products, Federal University of Paraíba, 58051-900 João Pessoa, PB, Brazil
- Laboratory of Synthesis and Drug Delivery, Biological Science Department, State University of Paraíba, 58071-160 João Pessoa, PB, Brazil
| |
Collapse
|
168
|
Sandoval R, Oliver C, Valdivia S, Valenzuela K, Haro RE, Sánchez P, Olavarría VH, Valenzuela P, Avendaño-Herrera R, Romero A, Cárcamo JG, Figueroa JE, Yáñez AJ. Resistance-nodulation-division efflux pump acrAB is modulated by florfenicol and contributes to drug resistance in the fish pathogenPiscirickettsia salmonis. FEMS Microbiol Lett 2016; 363:fnw102. [DOI: 10.1093/femsle/fnw102] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2016] [Indexed: 12/20/2022] Open
|
169
|
Abstract
Bacterial infections cause 300 million cases of severe illness each year worldwide. Rapidly accelerating drug resistance further exacerbates this threat to human health. While dispersed (planktonic) bacteria represent a therapeutic challenge, bacterial biofilms present major hurdles for both diagnosis and treatment. Nanoparticles have emerged recently as tools for fighting drug-resistant planktonic bacteria and biofilms. In this review, we present the use of nanoparticles as active antimicrobial agents and drug delivery vehicles for antibacterial therapeutics. We further focus on how surface functionality of nanomaterials can be used to target both planktonic bacteria and biofilms.
Collapse
Affiliation(s)
- Akash Gupta
- Department of Chemistry, University of Massachusetts Amherst, 710 North Pleasant Street, Amherst, Massachusetts, 01003, USA
| | - Ryan F Landis
- Department of Chemistry, University of Massachusetts Amherst, 710 North Pleasant Street, Amherst, Massachusetts, 01003, USA
| | - Vincent M Rotello
- Department of Chemistry, University of Massachusetts Amherst, 710 North Pleasant Street, Amherst, Massachusetts, 01003, USA
| |
Collapse
|
170
|
Møller TSB, Overgaard M, Nielsen SS, Bortolaia V, Sommer MOA, Guardabassi L, Olsen JE. Relation between tetR and tetA expression in tetracycline resistant Escherichia coli. BMC Microbiol 2016; 16:39. [PMID: 26969122 PMCID: PMC4788846 DOI: 10.1186/s12866-016-0649-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 02/29/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tetracyclines are among the most used antibiotics in livestock worldwide. Resistance is widely disseminated in Escherichia coli, where it is generally mediated by tetracycline efflux pumps, such as TetA. Expression of tetracycline efflux pumps is tightly controlled by the repressor TetR, which has been shown to be tetracycline-responsive at sub-MIC tetracycline concentrations. The objective of this study was to investigate the effects of increasing tetracycline concentrations on the growth of TetA-producing E. coli, and to determine how expression of tetA and tetR related to each other in different growth phases in the presence of tetracycline. RESULTS A tetracycline resistant E. coli strain containing tetA and tetR on the chromosome was constructed and cultured in the presence of increasing concentrations of tetracycline. Expression of tetR and tetA was measured at four time points in different growth phases by quantitative real-time PCR. The TetA-producing E. coli exhibited prolonged lag phase with increasing concentrations of tetracycline, while expression of tetA and tetR increased and decreased, respectively, with increasing tetracycline concentration. The levels of tetA and tetR mRNA varied depending on growth phase, resulting in a gradual decrease of the tetA/tetR ratio from approximately 4 in the lag phase to approximately 2 in the stationary phase. CONCLUSION This study shows that the expression of tetR and tetA is tetracycline concentration- and growth phase-dependent, contributing to improved understanding of the relationships between E. coli growth, tetracycline exposure and expression of tetracycline resistance.
Collapse
Affiliation(s)
- Thea S B Møller
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, C, Denmark
| | - Martin Overgaard
- Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, Odense, Denmark.,Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Søren S Nielsen
- Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, C, Denmark
| | - Valeria Bortolaia
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, C, Denmark
| | - Morten O A Sommer
- Department of Systems Biology, Technical University of Denmark, Lyngby, Denmark.,Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Hørsholm, Denmark
| | - Luca Guardabassi
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, C, Denmark
| | - John E Olsen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, C, Denmark.
| |
Collapse
|
171
|
Insight into determinants of substrate binding and transport in a multidrug efflux protein. Sci Rep 2016; 6:22833. [PMID: 26961153 PMCID: PMC4785361 DOI: 10.1038/srep22833] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 02/24/2016] [Indexed: 11/09/2022] Open
Abstract
Multidrug resistance arising from the activity of integral membrane transporter proteins presents a global public health threat. In bacteria such as Escherichia coli, transporter proteins belonging to the major facilitator superfamily make a considerable contribution to multidrug resistance by catalysing efflux of myriad structurally and chemically different antimicrobial compounds. Despite their clinical relevance, questions pertaining to mechanistic details of how these promiscuous proteins function remain outstanding, and the role(s) played by individual amino acid residues in recognition, binding and subsequent transport of different antimicrobial substrates by multidrug efflux members of the major facilitator superfamily requires illumination. Using in silico homology modelling, molecular docking and mutagenesis studies in combination with substrate binding and transport assays, we identified several amino acid residues that play important roles in antimicrobial substrate recognition, binding and transport by Escherichia coli MdtM, a representative multidrug efflux protein of the major facilitator superfamily. Furthermore, our studies suggested that ‘aromatic clamps’ formed by tyrosine and phenylalanine residues located within the substrate binding pocket of MdtM may be important for antimicrobial substrate recognition and transport by the protein. Such ‘clamps’ may be a structurally and functionally important feature of all major facilitator multidrug efflux proteins.
Collapse
|
172
|
Bains W. Low potency toxins reveal dense interaction networks in metabolism. BMC SYSTEMS BIOLOGY 2016; 10:19. [PMID: 26897366 PMCID: PMC4761184 DOI: 10.1186/s12918-016-0262-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 01/29/2016] [Indexed: 11/13/2022]
Abstract
BACKGROUND The chemicals of metabolism are constructed of a small set of atoms and bonds. This may be because chemical structures outside the chemical space in which life operates are incompatible with biochemistry, or because mechanisms to make or utilize such excluded structures has not evolved. In this paper I address the extent to which biochemistry is restricted to a small fraction of the chemical space of possible chemicals, a restricted subset that I call Biochemical Space. I explore evidence that this restriction is at least in part due to selection again specific structures, and suggest a mechanism by which this occurs. RESULTS Chemicals that contain structures that our outside Biochemical Space (UnBiological groups) are more likely to be toxic to a wide range of organisms, even though they have no specifically toxic groups and no obvious mechanism of toxicity. This correlation of UnBiological with toxicity is stronger for low potency (millimolar) toxins. I relate this to the observation that most chemicals interact with many biological structures at low millimolar toxicity. I hypothesise that life has to select its components not only to have a specific set of functions but also to avoid interactions with all the other components of life that might degrade their function. CONCLUSIONS The chemistry of life has to form a dense, self-consistent network of chemical structures, and cannot easily be arbitrarily extended. The toxicity of arbitrary chemicals is a reflection of the disruption to that network occasioned by trying to insert a chemical into it without also selecting all the other components to tolerate that chemical. This suggests new ways to test for the toxicity of chemicals, and that engineering organisms to make high concentrations of materials such as chemical precursors or fuels may require more substantial engineering than just of the synthetic pathways involved.
Collapse
Affiliation(s)
- William Bains
- Earth, Atmospheric and Planetary Sciences Department, MIT, 77 Mass Avenue, Cambridge, MA, 02139, USA.
- Rufus Scientific Ltd., 37 The Moor, Melbourn, Royston, Herts, SG8 6ED, UK.
| |
Collapse
|
173
|
Zhang C, Chen X, Stephanopoulos G, Too HP. Efflux transporter engineering markedly improves amorphadiene production inEscherichia coli. Biotechnol Bioeng 2016; 113:1755-63. [DOI: 10.1002/bit.25943] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 12/21/2015] [Accepted: 01/18/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Congqiang Zhang
- Chemical and Pharmaceutical Engineering; Singapore-MIT Alliance; 4 Engineering Drive 3 Singapore Singapore
- Biotransformation Innovation Platform (BioTrans); Agency for Science, Technology and Research (A*STAR); Singapore Singapore
| | - Xixian Chen
- Chemical and Pharmaceutical Engineering; Singapore-MIT Alliance; 4 Engineering Drive 3 Singapore Singapore
- Biotransformation Innovation Platform (BioTrans); Agency for Science, Technology and Research (A*STAR); Singapore Singapore
| | - Gregory Stephanopoulos
- Chemical and Pharmaceutical Engineering; Singapore-MIT Alliance; 4 Engineering Drive 3 Singapore Singapore
- Department of Chemical Engineering; Massachusetts Institute of Technology; Cambridge Massachusetts
| | - Heng-Phon Too
- Chemical and Pharmaceutical Engineering; Singapore-MIT Alliance; 4 Engineering Drive 3 Singapore Singapore
- Biotransformation Innovation Platform (BioTrans); Agency for Science, Technology and Research (A*STAR); Singapore Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine; National University of Singapore, 8 Medical Drive; Blk MD7, Level 4 Singapore 117597 Singapore
| |
Collapse
|
174
|
Liger F, Bouhours P, Ganem-Elbaz C, Jolivalt C, Pellet-Rostaing S, Popowycz F, Paris JM, Lemaire M. C2 Arylated Benzo[b]thiophene Derivatives asStaphylococcus aureusNorA Efflux Pump Inhibitors. ChemMedChem 2016; 11:320-30. [DOI: 10.1002/cmdc.201500463] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Indexed: 11/11/2022]
Affiliation(s)
- François Liger
- Equipe Catalyse Synthèse Environnement; CNRS-UMR 5246; L'Institut de Chimie et Biochimie Moléculaires et Supramoléculaires (ICBMS); 43 Bd. du 11 novembre 1918 69622 Villeurbanne France
| | - Pascale Bouhours
- Laboratoire Charles Friedel; CNRS-UMR 7223; Chimie ParisTech; 11 rue Pierre et Marie Curie 75005 Paris France
| | - Carine Ganem-Elbaz
- Laboratoire Charles Friedel; CNRS-UMR 7223; Chimie ParisTech; 11 rue Pierre et Marie Curie 75005 Paris France
| | - Claude Jolivalt
- Laboratoire Charles Friedel; CNRS-UMR 7223; Chimie ParisTech; 11 rue Pierre et Marie Curie 75005 Paris France
| | - Stéphane Pellet-Rostaing
- Equipe Catalyse Synthèse Environnement; CNRS-UMR 5246; L'Institut de Chimie et Biochimie Moléculaires et Supramoléculaires (ICBMS); 43 Bd. du 11 novembre 1918 69622 Villeurbanne France
| | - Florence Popowycz
- Institut National des Sciences Appliquées de Lyon; ICBMS, CNRS-UMR 5246, Equipe Chimie Organique et Bioorganique; 20 Avenue Albert Einstein 69621 Villeurbanne France
| | - Jean-Marc Paris
- Laboratoire Charles Friedel; CNRS-UMR 7223; Chimie ParisTech; 11 rue Pierre et Marie Curie 75005 Paris France
| | - Marc Lemaire
- Equipe Catalyse Synthèse Environnement; CNRS-UMR 5246; L'Institut de Chimie et Biochimie Moléculaires et Supramoléculaires (ICBMS); 43 Bd. du 11 novembre 1918 69622 Villeurbanne France
| |
Collapse
|
175
|
The Biocide and Antibiotic Resistance in Campylobacter jejuni and Campylobacter coli. FOOD ENGINEERING SERIES 2016. [DOI: 10.1007/978-3-319-24040-4_15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
|
176
|
Diversity, Antimicrobial Action and Structure-Activity Relationship of Buffalo Cathelicidins. PLoS One 2015; 10:e0144741. [PMID: 26675301 PMCID: PMC4684500 DOI: 10.1371/journal.pone.0144741] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 11/22/2015] [Indexed: 02/07/2023] Open
Abstract
Cathelicidins are an ancient class of antimicrobial peptides (AMPs) with broad spectrum bactericidal activities. In this study, we investigated the diversity and biological activity of cathelicidins of buffalo, a species known for its disease resistance. A series of new homologs of cathelicidin4 (CATHL4), which were structurally diverse in their antimicrobial domain, was identified in buffalo. AMPs of newly identified buffalo CATHL4s (buCATHL4s) displayed potent antimicrobial activity against selected Gram positive (G+) and Gram negative (G-) bacteria. These peptides were prompt to disrupt the membrane integrity of bacteria and induced specific changes such as blebing, budding, and pore like structure formation on bacterial membrane. The peptides assumed different secondary structure conformations in aqueous and membrane-mimicking environments. Simulation studies suggested that the amphipathic design of buCATHL4 was crucial for water permeation following membrane disruption. A great diversity, broad-spectrum antimicrobial action, and ability to induce an inflammatory response indicated the pleiotropic role of cathelicidins in innate immunity of buffalo. This study suggests short buffalo cathelicidin peptides with potent bactericidal properties and low cytotoxicity have potential translational applications for the development of novel antibiotics and antimicrobial peptidomimetics.
Collapse
|
177
|
Uptake of and Resistance to the Antibiotic Berberine by Individual Dormant, Germinating and Outgrowing Bacillus Spores as Monitored by Laser Tweezers Raman Spectroscopy. PLoS One 2015; 10:e0144183. [PMID: 26636757 PMCID: PMC4670213 DOI: 10.1371/journal.pone.0144183] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 11/13/2015] [Indexed: 12/24/2022] Open
Abstract
Berberine, an alkaloid originally extracted from the plant Coptis chinensis and other herb plants, has been used as a pharmacological substance for many years. The therapeutic effect of berberine has been attributed to its interaction with nucleic acids and blocking cell division. However, levels of berberine entering individual microbial cells minimal for growth inhibition and its effects on bacterial spores have not been determined. In this work the kinetics and levels of berberine accumulation by individual dormant and germinated spores were measured by laser tweezers Raman spectroscopy and differential interference and fluorescence microscopy, and effects of berberine on spore germination and outgrowth and spore and growing cell viability were determined. The major conclusions from this work are that: (1) colony formation from B. subtilis spores was blocked ~ 99% by 25 μg/mL berberine plus 20 μg/mL INF55 (a multidrug resistance pump inhibitor); (2) 200 μg/mL berberine had no effect on B. subtilis spore germination with L-valine, but spore outgrowth was completely blocked; (3) berberine levels accumulated in single spores germinating with ≥ 25 μg/mL berberine were > 10 mg/mL; (4) fluorescence microscopy showed that germinated spores accumulated high-levels of berberine primarily in the spore core, while dormant spores accumulated very low berberine levels primarily in spore coats; and (5) during germination, uptake of berberine began at the time of commitment (T1) and reached a maximum after the completion of CaDPA release (Trelease) and spore cortex lysis (Tlysis).
Collapse
|
178
|
Antimicrobial consumption and resistance in five Gram-negative bacterial species in a hospital from 2003 to 2011. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2015; 48:647-54. [DOI: 10.1016/j.jmii.2014.04.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 11/27/2013] [Accepted: 04/15/2014] [Indexed: 11/18/2022]
|
179
|
Jia S, Shi P, Hu Q, Li B, Zhang T, Zhang XX. Bacterial Community Shift Drives Antibiotic Resistance Promotion during Drinking Water Chlorination. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:12271-9. [PMID: 26397118 DOI: 10.1021/acs.est.5b03521] [Citation(s) in RCA: 283] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
For comprehensive insights into the effects of chlorination, a widely used disinfection technology, on bacterial community and antibiotic resistome in drinking water, this study applied high-throughput sequencing and metagenomic approaches to investigate the changing patterns of antibiotic resistance genes (ARGs) and bacterial community in a drinking water treatment and distribution system. At genus level, chlorination could effectively remove Methylophilus, Methylotenera, Limnobacter, and Polynucleobacter, while increase the relative abundance of Pseudomonas, Acidovorax, Sphingomonas, Pleomonas, and Undibacterium in the drinking water. A total of 151 ARGs within 15 types were detectable in the drinking water, and chlorination evidently increased their total relative abundance while reduced their diversity in the opportunistic bacteria (p < 0.05). Residual chlorine was identified as the key contributing factor driving the bacterial community shift and resistome alteration. As the dominant persistent ARGs in the treatment and distribution system, multidrug resistance genes (mainly encoding resistance-nodulation-cell division transportation system) and bacitracin resistance gene bacA were mainly carried by chlorine-resistant bacteria Pseudomonas and Acidovorax, which mainly contributed to the ARGs abundance increase. The strong correlation between bacterial community shift and antibiotic resistome alteration observed in this study may shed new light on the mechanism behind the chlorination effects on antibiotic resistance.
Collapse
Affiliation(s)
- Shuyu Jia
- State Key Laboratory of Pollution Control and Resource Reuse, Environmental Health Research Center, School of the Environment, Nanjing University , Nanjing 210023, China
| | - Peng Shi
- State Key Laboratory of Pollution Control and Resource Reuse, Environmental Health Research Center, School of the Environment, Nanjing University , Nanjing 210023, China
| | - Qing Hu
- State Key Laboratory of Pollution Control and Resource Reuse, Environmental Health Research Center, School of the Environment, Nanjing University , Nanjing 210023, China
| | - Bing Li
- Environmental Biotechnology Lab, Department of Civil Engineering, The University of Hong Kong , Hong Kong SAR, China
| | - Tong Zhang
- Environmental Biotechnology Lab, Department of Civil Engineering, The University of Hong Kong , Hong Kong SAR, China
| | - Xu-Xiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, Environmental Health Research Center, School of the Environment, Nanjing University , Nanjing 210023, China
| |
Collapse
|
180
|
Pule CM, Sampson SL, Warren RM, Black PA, van Helden PD, Victor TC, Louw GE. Efflux pump inhibitors: targeting mycobacterial efflux systems to enhance TB therapy. J Antimicrob Chemother 2015; 71:17-26. [DOI: 10.1093/jac/dkv316] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
|
181
|
Dwivedi GR, Maurya A, Yadav DK, Khan F, Darokar MP, Srivastava SK. Drug Resistance Reversal Potential of Ursolic Acid Derivatives against Nalidixic Acid- and Multidrug-resistant Escherichia coli. Chem Biol Drug Des 2015; 86:272-83. [PMID: 25476148 DOI: 10.1111/cbdd.12491] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 12/01/2014] [Accepted: 12/01/2014] [Indexed: 12/18/2022]
Abstract
As a part of our drug discovery program, ursolic acid was chemically transformed into six semi-synthetic derivatives, which were evaluated for their antibacterial and drug resistance reversal potential in combination with conventional antibiotic nalidixic acid against the nalidixic acid-sensitive and nalidixic acid-resistant strains of Escherichia coli. Although ursolic acid and its all semi-synthetic derivatives did not show antibacterial activity of their own, but in combination, they significantly reduced the minimum inhibitory concentration of nalidixic acid up to eightfold. The 3-O-acetyl-urs-12-en-28-isopropyl ester (UA-4) and 3-O-acetyl-urs-12-en-28-n-butyl ester (UA-5) derivatives of ursolic acid reduced the minimum inhibitory concentration of nalidixic acid by eightfold against nalidixic acid-resistant and four and eightfold against nalidixic acid-sensitive, respectively. The UA-4 and UA-5 were further evaluated for their synergy potential with another antibiotic tetracycline against the multidrug-resistant clinical isolate of Escherichia coli-KG4. The results showed that both these derivatives in combination with tetracycline reduced the cell viability in concentration-dependent manner by significantly inhibiting efflux pump. This was further supported by the in silico binding affinity of UA-4 and UA-5 with efflux pump proteins. These ursolic acid derivatives may find their potential use as synergistic agents in the treatment of multidrug-resistant Gram-negative infections.
Collapse
Affiliation(s)
- Gaurav Raj Dwivedi
- Molecular Bioprospection Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, India
| | - Anupam Maurya
- Medicinal Chemistry Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, India
| | - Dharmendra Kumar Yadav
- Metabolic & Structural Biology, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, India
| | - Feroz Khan
- Metabolic & Structural Biology, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, India
| | - Mahendra P Darokar
- Molecular Bioprospection Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, India
| | - Santosh Kumar Srivastava
- Medicinal Chemistry Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, India
| |
Collapse
|
182
|
Laverty G, McCloskey AP, Gorman SP, Gilmore BF. Anti-biofilm activity of ultrashort cinnamic acid peptide derivatives against medical device-related pathogens. J Pept Sci 2015; 21:770-8. [PMID: 26310860 DOI: 10.1002/psc.2805] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 06/26/2015] [Accepted: 07/06/2015] [Indexed: 11/11/2022]
Abstract
The threat of antimicrobial resistance has placed increasing emphasis on the development of innovative approaches to eradicate multidrug-resistant pathogens. Biofilm-forming microorganisms, for example, Staphylococcus epidermidis and Staphylococcus aureus, are responsible for increased incidence of biomaterial infection, extended hospital stays and patient morbidity and mortality. This paper highlights the potential of ultrashort tetra-peptide conjugated to hydrophobic cinnamic acid derivatives. These peptidomimetic molecules demonstrate selective and highly potent activity against resistant biofilm forms of Gram-positive medical device-related pathogens. 3-(4-Hydroxyphenyl)propionic)-Orn-Orn-Trp-Trp-NH2 displays particular promise with minimum biofilm eradication concentration (MBEC) values of 125 µg/ml against methicillin sensitive (ATCC 29213) and resistant (ATCC 43300) S. aureus and activity shown against biofilm forms of Escherichia coli (MBEC: 1000 µg/ml). Kill kinetics confirms complete eradication of established 24-h biofilms at MBEC with 6-h exposure. Reduced cell cytotoxicity, relative to Gram-positive pathogens, was proven via tissue culture (HaCaT) and haemolysis assays (equine erythrocytes). Existing in nature as part of the immune response, antimicrobial peptides display great promise for exploitation by the pharmaceutical industry in order to increase the library of available therapeutic molecules. Ultrashort variants are particularly promising for translation as clinical therapeutics as they are more cost-effective, easier to synthesise and can be tailored to specific functional requirements based on the primary sequence allowing factors such as spectrum of activity to be varied.
Collapse
Affiliation(s)
- Garry Laverty
- Biomaterials, Biofilm and Infection Control Research Group, School of Pharmacy, Queen's University of Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - Alice P McCloskey
- Biomaterials, Biofilm and Infection Control Research Group, School of Pharmacy, Queen's University of Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - Sean P Gorman
- Biomaterials, Biofilm and Infection Control Research Group, School of Pharmacy, Queen's University of Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - Brendan F Gilmore
- Biomaterials, Biofilm and Infection Control Research Group, School of Pharmacy, Queen's University of Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| |
Collapse
|
183
|
Dwivedi GR, Gupta S, Maurya A, Tripathi S, Sharma A, Darokar MP, Srivastava SK. Synergy Potential of Indole Alkaloids and Its Derivative against Drug-resistantEscherichia coli. Chem Biol Drug Des 2015; 86:1471-81. [DOI: 10.1111/cbdd.12613] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 06/12/2015] [Accepted: 06/19/2015] [Indexed: 01/01/2023]
Affiliation(s)
- Gaurav Raj Dwivedi
- Biotechnology Division; Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP); P.O.- CIMAP Lucknow 226015 India
- School of Environmental Sciences; Babasaheb Bhimrao Ambedkar Central University; Vidya Vihar, Rae Bareli Road Lucknow 226025 India
| | - Shikha Gupta
- Medicinal Chemistry Department; Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP); P.O.- CIMAP Lucknow 226015 India
| | - Anupam Maurya
- Medicinal Chemistry Department; Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP); P.O.- CIMAP Lucknow 226015 India
| | - Shubhandra Tripathi
- Biotechnology Division; Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP); P.O.- CIMAP Lucknow 226015 India
| | - Ashok Sharma
- Biotechnology Division; Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP); P.O.- CIMAP Lucknow 226015 India
| | - Mahendra P. Darokar
- Biotechnology Division; Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP); P.O.- CIMAP Lucknow 226015 India
| | - Santosh K. Srivastava
- Medicinal Chemistry Department; Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP); P.O.- CIMAP Lucknow 226015 India
| |
Collapse
|
184
|
Youenou B, Favre-Bonté S, Bodilis J, Brothier E, Dubost A, Muller D, Nazaret S. Comparative Genomics of Environmental and Clinical Stenotrophomonas maltophilia Strains with Different Antibiotic Resistance Profiles. Genome Biol Evol 2015; 7:2484-505. [PMID: 26276674 PMCID: PMC4607518 DOI: 10.1093/gbe/evv161] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Stenotrophomonas maltophilia, a ubiquitous Gram-negative γ-proteobacterium, has emerged as an important opportunistic pathogen responsible for nosocomial infections. A major characteristic of clinical isolates is their high intrinsic or acquired antibiotic resistance level. The aim of this study was to decipher the genetic determinism of antibiotic resistance among strains from different origins (i.e., natural environment and clinical origin) showing various antibiotic resistance profiles. To this purpose, we selected three strains isolated from soil collected in France or Burkina Faso that showed contrasting antibiotic resistance profiles. After whole-genome sequencing, the phylogenetic relationships of these 3 strains and 11 strains with available genome sequences were determined. Results showed that a strain's phylogeny did not match their origin or antibiotic resistance profiles. Numerous antibiotic resistance coding genes and efflux pump operons were revealed by the genome analysis, with 57% of the identified genes not previously described. No major variation in the antibiotic resistance gene content was observed between strains irrespective of their origin and antibiotic resistance profiles. Although environmental strains generally carry as many multidrug resistant (MDR) efflux pumps as clinical strains, the absence of resistance-nodulation-division (RND) pumps (i.e., SmeABC) previously described to be specific to S. maltophilia was revealed in two environmental strains (BurA1 and PierC1). Furthermore the genome analysis of the environmental MDR strain BurA1 showed the absence of SmeABC but the presence of another putative MDR RND efflux pump, named EbyCAB on a genomic island probably acquired through horizontal gene transfer.
Collapse
Affiliation(s)
- Benjamin Youenou
- Université de Lyon, France; Research Group on Environmental Multi-Resistance and Efflux Pump, CNRS, Ecole Nationale Vétérinaire de Lyon, and Université Lyon 1, UMR 5557 Ecologie Microbienne, Villeurbanne, France
| | - Sabine Favre-Bonté
- Université de Lyon, France; Research Group on Environmental Multi-Resistance and Efflux Pump, CNRS, Ecole Nationale Vétérinaire de Lyon, and Université Lyon 1, UMR 5557 Ecologie Microbienne, Villeurbanne, France
| | - Josselin Bodilis
- EA4312 Laboratoire de Microbiologie Signaux et Microenvironnement, Université de Rouen, Mont-Saint-Aignan, France
| | - Elisabeth Brothier
- Université de Lyon, France; Research Group on Environmental Multi-Resistance and Efflux Pump, CNRS, Ecole Nationale Vétérinaire de Lyon, and Université Lyon 1, UMR 5557 Ecologie Microbienne, Villeurbanne, France
| | - Audrey Dubost
- Université de Lyon, France; Research Group on Environmental Multi-Resistance and Efflux Pump, CNRS, Ecole Nationale Vétérinaire de Lyon, and Université Lyon 1, UMR 5557 Ecologie Microbienne, Villeurbanne, France
| | - Daniel Muller
- Université de Lyon, France; Research Group on Environmental Multi-Resistance and Efflux Pump, CNRS, Ecole Nationale Vétérinaire de Lyon, and Université Lyon 1, UMR 5557 Ecologie Microbienne, Villeurbanne, France
| | - Sylvie Nazaret
- Université de Lyon, France; Research Group on Environmental Multi-Resistance and Efflux Pump, CNRS, Ecole Nationale Vétérinaire de Lyon, and Université Lyon 1, UMR 5557 Ecologie Microbienne, Villeurbanne, France
| |
Collapse
|
185
|
Grabke A, Stammler G. A Botrytis cinerea Population from a Single Strawberry Field in Germany has a Complex Fungicide Resistance Pattern. PLANT DISEASE 2015; 99:1078-1086. [PMID: 30695938 DOI: 10.1094/pdis-07-14-0710-re] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Gray mold, caused by the fungus Botrytis cinerea, is one of the most important diseases of strawberry in Germany. The application of site-specific fungicides remains the main strategy to reduce disease incidence and severity in the field. Isolates (n = 199) were collected from fungicide-treated strawberry fruit at a German research site with a long history of fungicide efficacy trials against gray mold. Sensitivities to the six site-specific botryticides registered in Germany were determined using microtiter assays. Values for the concentration of a fungicide at which fungal development is inhibited by 50% (EC50) ranged from 0.03 to ≥30 ppm for the succinate dehydrogenase inhibitor boscalid, 0.015 to ≥10 ppm for the hydroxyanilide fenhexamid, 0.009 to 0.739 ppm for the phenylpyrrole fludioxonil, 0.55 to 43.45 ppm for the dicarboximide iprodione, 0.021 to ≥3 ppm for the quinone outside inhibitor pyraclostrobin, and 0.106 to ≥30 ppm for the anilinopyrimidine pyrimethanil. Pyrosequencing revealed that amino acid substitutions in the target proteins Bos1 (I365S/N, V368F + Q369H), CytB (G143A), Erg27 (F412S), and SdhB (P225F, N230I, and H272R/Y) were associated with reduced sensitivity levels to the corresponding fungicide classes. In most cases, isolates with a decreased sensitivity to fludioxonil showed a reduced sensitivity to tolnaftate. This reduction is considered to be an indication of multidrug efflux pump activity. The amino acid change I365S, I365N, or V368F + Q369H in Bos1 and H272R in SdhB by itself showed EC50 values of 3.99 to 14.73 ppm, 3.87 to 5.37 ppm, 4.81 to 15.63 ppm, and 2.071 to ≥30 ppm, respectively. When isolates that contained one of these mutations were also multidrug resistant, the ranges of EC50 values shifted to 6.47 to 43.45 ppm for I365S, 7.28 to 29.84 ppm for I365N, 6.89 to 26.67 ppm for V368F + Q369H, and ≥30 ppm for H272R. The reported data suggest that the combination of multidrug resistance and an amino acid change in the target site may result in a lower sensitivity to the fungicides than one resistance mechanism by itself. Although 20% of the population analyzed was sensitive to all six different chemical classes, the majority showed reduced sensitivity to one (6%), two (13%), three (23%), four (17%), five (11%), and six (11%) different fungicides.
Collapse
Affiliation(s)
- Anja Grabke
- School of Agricultural, Forest & Environmental Sciences, Clemson University, Clemson, SC 29634
| | - Gerd Stammler
- BASF SE, Agricultural Research Station, 67117 Limburgerhof, Germany
| |
Collapse
|
186
|
MATEPRED-A-SVM-Based Prediction Method for Multidrug And Toxin Extrusion (MATE) Proteins. Comput Biol Chem 2015; 58:199-204. [PMID: 26256800 DOI: 10.1016/j.compbiolchem.2015.07.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 07/20/2015] [Accepted: 07/25/2015] [Indexed: 11/23/2022]
Abstract
The growth and spread of drug resistance in bacteria have been well established in both mankind and beasts and thus is a serious public health concern. Due to the increasing problem of drug resistance, control of infectious diseases like diarrhea, pneumonia etc. is becoming more difficult. Hence, it is crucial to understand the underlying mechanism of drug resistance mechanism and devising novel solution to address this problem. Multidrug And Toxin Extrusion (MATE) proteins, first characterized as bacterial drug transporters, are present in almost all species. It plays a very important function in the secretion of cationic drugs across the cell membrane. In this work, we propose SVM based method for prediction of MATE proteins. The data set employed for training consists of 189 non-redundant protein sequences, that are further classified as positive (63 sequences) set comprising of sequences from MATE family, and negative (126 sequences) set having protein sequences from other transporters families proteins and random protein sequences taken from NCBI while in the test set, there are 120 protein sequences in all (8 in positive and 112 in negative set). The model was derived using Position Specific Scoring Matrix (PSSM) composition and achieved an overall accuracy 92.06%. The five-fold cross validation was used to optimize SVM parameter and select the best model. The prediction algorithm presented here is implemented as a freely available web server MATEPred, which will assist in rapid identification of MATE proteins.
Collapse
|
187
|
Hittle LE, Powell DA, Jones JW, Tofigh M, Goodlett DR, Moskowitz SM, Ernst RK. Site-specific activity of the acyltransferases HtrB1 and HtrB2 in Pseudomonas aeruginosa lipid A biosynthesis. Pathog Dis 2015. [PMID: 26223882 DOI: 10.1093/femspd/ftv053] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Pseudomonas aeruginosa (PA) is an opportunistic Gram-negative pathogen associated with nosocomial infections, acute infections and chronic lung infections in patients with cystic fibrosis. The ability of PA to cause infection can be attributed to its ability to adapt to a multitude of environments. Modification of the lipid A portion of lipopolysaccharide (LPS) is a vital mechanism Gram-negative pathogens use to remodel the outer membrane in response to environmental stimuli. Lipid A, the endotoxic moiety of LPS, is the major component of the outer leaflet of the outer membrane of Gram-negative bacteria making it a critical factor for bacterial adaptation. One way PA modifies its lipid A is through the addition of laurate and 2-hydroxylaurate. This secondary or late acylation is carried out by the acyltransferase, HtrB (LpxL). Analysis of the PA genome revealed the presence of two htrB homologs, PA0011 (htrB1) and PA3242 (htrB2). In this study, we were able to show that each gene identified is responsible for site-specific modification of lipid A. Additionally, deletions of either gene altered resistance to specific classes of antibiotics, cationic antimicrobial peptides and increased membrane permeability suggesting a role for these enzymes in maintaining optimal membrane organization and integrity.
Collapse
Affiliation(s)
- Lauren E Hittle
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Daniel A Powell
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Jace W Jones
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, Seattle, WA 98195, USA
| | - Majid Tofigh
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - David R Goodlett
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, Seattle, WA 98195, USA
| | - Samuel M Moskowitz
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, Seattle, WA 98195, USA Department of Pediatrics, Massachusetts General Hospital, Boston, MA 20114, USA
| | - Robert K Ernst
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| |
Collapse
|
188
|
Abstract
Quinolone antimicrobials are synthetic and widely used in clinical medicine. Resistance emerged with clinical use and became common in some bacterial pathogens. Mechanisms of resistance include two categories of mutation and acquisition of resistance-conferring genes. Resistance mutations in one or both of the two drug target enzymes, DNA gyrase and DNA topoisomerase IV, are commonly in a localized domain of the GyrA and ParE subunits of the respective enzymes and reduce drug binding to the enzyme-DNA complex. Other resistance mutations occur in regulatory genes that control the expression of native efflux pumps localized in the bacterial membrane(s). These pumps have broad substrate profiles that include quinolones as well as other antimicrobials, disinfectants, and dyes. Mutations of both types can accumulate with selection pressure and produce highly resistant strains. Resistance genes acquired on plasmids can confer low-level resistance that promotes the selection of mutational high-level resistance. Plasmid-encoded resistance is due to Qnr proteins that protect the target enzymes from quinolone action, one mutant aminoglycoside-modifying enzyme that also modifies certain quinolones, and mobile efflux pumps. Plasmids with these mechanisms often encode additional antimicrobial resistances and can transfer multidrug resistance that includes quinolones. Thus, the bacterial quinolone resistance armamentarium is large.
Collapse
Affiliation(s)
- David C Hooper
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - George A Jacoby
- Lahey Hospital and Medical Center, Burlington, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| |
Collapse
|
189
|
Expression of the AcrAB Components of the AcrAB-TolC Multidrug Efflux Pump of Yersinia enterocolitica Is Subject to Dual Regulation by OmpR. PLoS One 2015; 10:e0124248. [PMID: 25893523 PMCID: PMC4403819 DOI: 10.1371/journal.pone.0124248] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 02/28/2015] [Indexed: 11/19/2022] Open
Abstract
OmpR is a transcriptional regulator implicated in the control of various cellular processes and functions in Enterobacteriaceae. This study was undertaken to identify genes comprising the OmpR regulon in the human gastrointestinal pathogen Yersinia enterocolitica. Derivatives of an ompR-negative strain with random transposon insertions creating transcriptional fusions with the reporter gene lacZ were isolated. These were supplied with the wild-type ompR allele in trans and then screened for OmpR-dependent changes in β-galactosidase activity. Using this strategy, five insertions in genes/operons positively regulated by OmpR and two insertions in genes negatively regulated by this protein were identified. Genetic analysis of one of these fusion strains revealed that the gene acrR, encoding transcriptional repressor AcrR is negatively regulated by OmpR. Differential analysis of membrane proteins by SDS-PAGE followed by mass spectrometry identified the protein AcrB, a component of the AcrAB-TolC multidrug efflux pump, as being positively regulated by OmpR. Analysis of the activity of the acrR and acrAB promoters using gfp fusions confirmed their OmpR-dependent repression and activation, respectively. The identification of putative OmpR-binding sites and electrophoretic mobility shift assays confirmed that this regulator binds specifically to both promoter regions with different affinity. Examination of the activity of the acrR and acrAB promoters after the exposure of cells to different chemicals showed that bile salts can act as an OmpR-independent inducer. Taken together, our findings suggest that OmpR positively controls the expression of the AcrAB-TolC efflux pump involved in the adaptive response of Y. enterocolitica O:9 to different chemical stressors, thus conferring an advantage in particular ecological niches.
Collapse
|
190
|
Cabral V, Luo X, Junqueira E, Costa SS, Mulhovo S, Duarte A, Couto I, Viveiros M, Ferreira MJU. Enhancing activity of antibiotics against Staphylococcus aureus: Zanthoxylum capense constituents and derivatives. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2015; 22:469-476. [PMID: 25925969 DOI: 10.1016/j.phymed.2015.02.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 01/12/2015] [Accepted: 02/10/2015] [Indexed: 06/04/2023]
Abstract
Six compounds (1-6), isolated from the methanol extract of the roots of the African medicinal plant Zanthoxylum capense Thunb. (Rutaceae), and seven ester derivatives (7-13) were evaluated for their antibacterial activities and modulatory effects on the MIC of antibiotics (erythromycin, oxacillin, and tetracycline) and ethidium bromide (EtBr) against a Staphylococcus aureus reference strain (ATCC 6538). Using the same model, compounds 1-13 were also assessed for their potential as efflux pump inhibitors by a fluorometric assay that measures the accumulation of the broad range efflux pump substrate EtBr. Compounds 8 and 11 were further evaluated for their antibacterial, modulatory and EtBr accumulation effects against four additional S. aureus strains, which included two clinical methicillin-resistant S. aureus (MRSA) strains. Compounds (1-13) have not shown antibacterial activity at the concentration ranges tested. When evaluated against S. aureus ATCC 6538, oxychelerythrine (1) a benzophenanthridine alkaloid, showed the highest modulatory activity enhancing the susceptibility of this strain to all the tested antibiotics from two to four-fold. Ailanthoidiol diacetate (8) and ailanthoidiol di-2-ethylbutanoate (11) were also good modulators when combined with EtBr, increasing the bacteria susceptibility by four and two-fold, respectively. In the EtBr accumulation assay, using ATCC 6538 strain, the phenylpropanoid (+)-ailanthoidiol (6) and most of its ester derivatives (8-11) exhibited higher activity than the positive control verapamil. The highest effects were found for compounds 8 and 11 that also increased the accumulation of EtBr, using S. aureus ATCC 25923 as model. Furthermore, both compounds (8, 11) were able to enhance the ciprofloxacin activity against the MRSA clinical strains tested, causing a reduction of the antibiotic MIC values from two to four-fold. The EtBr accumulation assay revealed that this modulation activity was not due to an inhibition of efflux pumps mechanism. These results suggested that Z. capense constituents may be valuable as leads for restoring antibiotic activity against MRSA strains.
Collapse
Affiliation(s)
- Vanessa Cabral
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Professor Gama Pinto, 1649-003 Lisboa, Portugal
| | - Xuan Luo
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Professor Gama Pinto, 1649-003 Lisboa, Portugal
| | - Elisabete Junqueira
- Grupo de Micobactérias, Unidade de Microbiologia Médica, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 100, 1349-008 Lisboa, Portugal
| | - Sofia S Costa
- Grupo de Micobactérias, Unidade de Microbiologia Médica, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 100, 1349-008 Lisboa, Portugal; Centro de Recursos Microbiológicos (CREM), Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Caparica, Portugal
| | - Silva Mulhovo
- Centro de Estudos Moçambicanos e de Etnociências (CEMEC), Faculdade de Ciências Naturais e Matemática, Universidade Pedagógica, Campus de Lhanguene, Av. de Moçambique, 21402161 Maputo, Moçambique
| | - Aida Duarte
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Professor Gama Pinto, 1649-003 Lisboa, Portugal
| | - Isabel Couto
- Grupo de Micobactérias, Unidade de Microbiologia Médica, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 100, 1349-008 Lisboa, Portugal; Centro de Recursos Microbiológicos (CREM), Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Caparica, Portugal
| | - Miguel Viveiros
- Grupo de Micobactérias, Unidade de Microbiologia Médica, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 100, 1349-008 Lisboa, Portugal; Centro de Malária e Outras Doenças Tropicais (CMDT), Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 100, 1349-008 Lisboa, Portugal
| | - Maria-José U Ferreira
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Professor Gama Pinto, 1649-003 Lisboa, Portugal.
| |
Collapse
|
191
|
Li XZ, Plésiat P, Nikaido H. The challenge of efflux-mediated antibiotic resistance in Gram-negative bacteria. Clin Microbiol Rev 2015; 28:337-418. [PMID: 25788514 PMCID: PMC4402952 DOI: 10.1128/cmr.00117-14] [Citation(s) in RCA: 899] [Impact Index Per Article: 99.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The global emergence of multidrug-resistant Gram-negative bacteria is a growing threat to antibiotic therapy. The chromosomally encoded drug efflux mechanisms that are ubiquitous in these bacteria greatly contribute to antibiotic resistance and present a major challenge for antibiotic development. Multidrug pumps, particularly those represented by the clinically relevant AcrAB-TolC and Mex pumps of the resistance-nodulation-division (RND) superfamily, not only mediate intrinsic and acquired multidrug resistance (MDR) but also are involved in other functions, including the bacterial stress response and pathogenicity. Additionally, efflux pumps interact synergistically with other resistance mechanisms (e.g., with the outer membrane permeability barrier) to increase resistance levels. Since the discovery of RND pumps in the early 1990s, remarkable scientific and technological advances have allowed for an in-depth understanding of the structural and biochemical basis, substrate profiles, molecular regulation, and inhibition of MDR pumps. However, the development of clinically useful efflux pump inhibitors and/or new antibiotics that can bypass pump effects continues to be a challenge. Plasmid-borne efflux pump genes (including those for RND pumps) have increasingly been identified. This article highlights the recent progress obtained for organisms of clinical significance, together with methodological considerations for the characterization of MDR pumps.
Collapse
Affiliation(s)
- Xian-Zhi Li
- Human Safety Division, Veterinary Drugs Directorate, Health Products and Food Branch, Health Canada, Ottawa, Ontario, Canada
| | - Patrick Plésiat
- Laboratoire de Bactériologie, Faculté de Médecine-Pharmacie, Centre Hospitalier Régional Universitaire, Université de Franche-Comté, Besançon, France
| | - Hiroshi Nikaido
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA
| |
Collapse
|
192
|
Nguyen ST, Kwasny SM, Ding X, Cardinale SC, McCarthy CT, Kim HS, Nikaido H, Peet NP, Williams JD, Bowlin TL, Opperman TJ. Structure-activity relationships of a novel pyranopyridine series of Gram-negative bacterial efflux pump inhibitors. Bioorg Med Chem 2015; 23:2024-34. [PMID: 25818767 DOI: 10.1016/j.bmc.2015.03.016] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 02/25/2015] [Accepted: 03/05/2015] [Indexed: 12/24/2022]
Abstract
Recently we described a novel pyranopyridine inhibitor (MBX2319) of RND-type efflux pumps of the Enterobacteriaceae. MBX2319 (3,3-dimethyl-5-cyano-8-morpholino-6-(phenethylthio)-3,4-dihydro-1H-pyrano[3,4-c]pyridine) is structurally distinct from other known Gram-negative efflux pump inhibitors (EPIs), such as 1-(1-naphthylmethyl)-piperazine (NMP), phenylalanylarginine-β-naphthylamide (PAβN), D13-9001, and the pyridopyrimidine derivatives. Here, we report the synthesis and biological evaluation of 60 new analogs of MBX2319 that were designed to probe the structure activity relationships (SARs) of the pyranopyridine scaffold. The results of these studies produced a molecular activity map of the scaffold, which identifies regions that are critical to efflux inhibitory activities and those that can be modified to improve potency, metabolic stability and solubility. Several compounds, such as 22d-f, 22i and 22k, are significantly more effective than MBX2319 at potentiating the antibacterial activity of levofloxacin and piperacillin against Escherichia coli.
Collapse
Affiliation(s)
- Son T Nguyen
- Microbiotix, Inc., One Innovation Dr., Worcester, MA 01605, USA.
| | - Steven M Kwasny
- Microbiotix, Inc., One Innovation Dr., Worcester, MA 01605, USA.
| | - Xiaoyuan Ding
- Microbiotix, Inc., One Innovation Dr., Worcester, MA 01605, USA.
| | | | | | - Hong-Suk Kim
- Department of Molecular and Cell Biology, University of California Berkeley, 16 Barker Hall # 3202, Berkeley, CA 94720-3202, USA.
| | - Hiroshi Nikaido
- Department of Molecular and Cell Biology, University of California Berkeley, 16 Barker Hall # 3202, Berkeley, CA 94720-3202, USA.
| | - Norton P Peet
- Microbiotix, Inc., One Innovation Dr., Worcester, MA 01605, USA.
| | - John D Williams
- Microbiotix, Inc., One Innovation Dr., Worcester, MA 01605, USA.
| | - Terry L Bowlin
- Microbiotix, Inc., One Innovation Dr., Worcester, MA 01605, USA.
| | | |
Collapse
|
193
|
Andersen JL, He GX, Kakarla P, K C R, Kumar S, Lakra WS, Mukherjee MM, Ranaweera I, Shrestha U, Tran T, Varela MF. Multidrug efflux pumps from Enterobacteriaceae, Vibrio cholerae and Staphylococcus aureus bacterial food pathogens. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:1487-547. [PMID: 25635914 PMCID: PMC4344678 DOI: 10.3390/ijerph120201487] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 01/15/2015] [Indexed: 02/07/2023]
Abstract
Foodborne illnesses caused by bacterial microorganisms are common worldwide and constitute a serious public health concern. In particular, microorganisms belonging to the Enterobacteriaceae and Vibrionaceae families of Gram-negative bacteria, and to the Staphylococcus genus of Gram-positive bacteria are important causative agents of food poisoning and infection in the gastrointestinal tract of humans. Recently, variants of these bacteria have developed resistance to medically important chemotherapeutic agents. Multidrug resistant Escherichia coli, Salmonella enterica, Vibrio cholerae, Enterobacter spp., and Staphylococcus aureus are becoming increasingly recalcitrant to clinical treatment in human patients. Of the various bacterial resistance mechanisms against antimicrobial agents, multidrug efflux pumps comprise a major cause of multiple drug resistance. These multidrug efflux pump systems reside in the biological membrane of the bacteria and actively extrude antimicrobial agents from bacterial cells. This review article summarizes the evolution of these bacterial drug efflux pump systems from a molecular biological standpoint and provides a framework for future work aimed at reducing the conditions that foster dissemination of these multidrug resistant causative agents through human populations.
Collapse
Affiliation(s)
- Jody L Andersen
- Department of Biology, Eastern New Mexico University, Portales, NM 88130, USA.
| | - Gui-Xin He
- Department of Clinical Laboratory and Nutritional Sciences, University of Massachusetts Lowell, Lowell, MA 01854, USA.
| | - Prathusha Kakarla
- Department of Biology, Eastern New Mexico University, Portales, NM 88130, USA.
| | - Ranjana K C
- Department of Biology, Eastern New Mexico University, Portales, NM 88130, USA.
| | - Sanath Kumar
- QC Laboratory, Harvest and Post-Harvest Technology Division, Central Institute of Fisheries Education (CIFE), Seven Bungalows, Versova, Andheri (W), Mumbai 400061, India.
| | - Wazir Singh Lakra
- QC Laboratory, Harvest and Post-Harvest Technology Division, Central Institute of Fisheries Education (CIFE), Seven Bungalows, Versova, Andheri (W), Mumbai 400061, India.
| | - Mun Mun Mukherjee
- Department of Biology, Eastern New Mexico University, Portales, NM 88130, USA.
| | - Indrika Ranaweera
- Department of Biology, Eastern New Mexico University, Portales, NM 88130, USA.
| | - Ugina Shrestha
- Department of Biology, Eastern New Mexico University, Portales, NM 88130, USA.
| | - Thuy Tran
- Department of Clinical Laboratory and Nutritional Sciences, University of Massachusetts Lowell, Lowell, MA 01854, USA.
| | - Manuel F Varela
- Department of Biology, Eastern New Mexico University, Portales, NM 88130, USA.
| |
Collapse
|
194
|
Meriläinen L, Herranen A, Schwarzbach A, Gilbert L. Morphological and biochemical features of Borrelia burgdorferi pleomorphic forms. MICROBIOLOGY-SGM 2015; 161:516-27. [PMID: 25564498 PMCID: PMC4339653 DOI: 10.1099/mic.0.000027] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The spirochaete bacterium Borrelia burgdorferi sensu lato is the causative agent of Lyme disease, the most common tick-borne infection in the northern hemisphere. There is a long-standing debate regarding the role of pleomorphic forms in Lyme disease pathogenesis, while very little is known about the characteristics of these morphological variants. Here, we present a comprehensive analysis of B. burgdorferi pleomorphic formation in different culturing conditions at physiological temperature. Interestingly, human serum induced the bacterium to change its morphology to round bodies (RBs). In addition, biofilm-like colonies in suspension were found to be part of B. burgdorferi’s normal in vitro growth. Further studies provided evidence that spherical RBs had an intact and flexible cell envelope, demonstrating that they are not cell wall deficient, or degenerative as previously implied. However, the RBs displayed lower metabolic activity compared with spirochaetes. Furthermore, our results indicated that the different pleomorphic variants were distinguishable by having unique biochemical signatures. Consequently, pleomorphic B. burgdorferi should be taken into consideration as being clinically relevant and influence the development of novel diagnostics and treatment protocols.
Collapse
Affiliation(s)
- Leena Meriläinen
- Department of Biological and Environmental Sciences and NanoScience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Anni Herranen
- Department of Biological and Environmental Sciences and NanoScience Center, University of Jyväskylä, Jyväskylä, Finland
| | | | - Leona Gilbert
- Department of Biological and Environmental Sciences and NanoScience Center, University of Jyväskylä, Jyväskylä, Finland
| |
Collapse
|
195
|
Garcia-Echauri SA, Cardineau GA. TETX: a novel nuclear selection marker for Chlamydomonas reinhardtii transformation. PLANT METHODS 2015; 11:27. [PMID: 25908936 PMCID: PMC4407551 DOI: 10.1186/s13007-015-0064-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 03/12/2015] [Indexed: 05/09/2023]
Abstract
BACKGROUND Transformation of microalgae to obtain recombinant proteins, lipids or metabolites of economic value is of growing interest due to low costs associated with culture growth and scaling up. At present there are only three stable nuclear selection markers for the transformation of Chlamydomonas reinhardtii, which is the most commonly transformed microalgae, specifically: the aminoglycoside phosphotransferaseses aph7and aphVIII and the phleomycin resistance ble gene. As several microalgae are resistant to some of the antibiotics associated with the mentioned resistance genes, we have developed another alternative, tetX, a NADP-requiring Oxidoreductase that hydroxylates tetracycline substrates. We provide evidence that tetX can be used to obtain nuclear transformants of Chlamydomonas reinhardtii. RESULTS We obtained nuclear transformants harbouring the tetX gene under the control of beta 2 tubulin or HSP70ARBCS2 promoters at an efficiency of transformation of 3.28 and 6.18 colony forming units/μg DNA respectively. This is the first report of a eukaryotic cell transformed using tetracycline as a selectable marker. CONCLUSIONS We developed a protocol for the nuclear transformation of Chlamydomonas reinhardtii using tetX as a selectable marker that confers stable resistance to tetracycline up to 100 μg/mL. We believe tetX can be used to transform Chlamydomonas reinhardtii chloroplasts, related microalgae and other aerobic organisms sensitive to any tetracycline antibiotic.
Collapse
Affiliation(s)
- Sergio A Garcia-Echauri
- />Centro de Biotecnología-FEMSA, Tecnológico de Monterrey, Monterrey, México
- />Centro de Agrobiotecnología, Tecnológico de Monterrey, Monterrey, México
| | - Guy A Cardineau
- />Centro de Biotecnología-FEMSA, Tecnológico de Monterrey, Monterrey, México
- />Centro de Agrobiotecnología, Tecnológico de Monterrey, Monterrey, México
| |
Collapse
|
196
|
Yilmaz S, Altinkanat-Gelmez G, Bolelli K, Guneser-Merdan D, Ufuk Over-Hasdemir M, Aki-Yalcin E, Yalcin I. Binding site feature description of 2-substituted benzothiazoles as potential AcrAB-TolC efflux pump inhibitors in E. coli. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2015; 26:853-871. [PMID: 26559566 DOI: 10.1080/1062936x.2015.1106581] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The resistance-nodulation-division (RND) family efflux pumps are important in the antibiotic resistance of Gram-negative bacteria. However, although a number of bacterial RND efflux pump inhibitors have been developed, there has been no clinically available RND efflux pump inhibitor to date. A set of BSN-coded 2-substituted benzothiazoles were tested alone and in combinations with ciprofloxacin (CIP) against the AcrAB-TolC overexpressor Escherichia coli AG102 clinical strain. The results indicated that the BSN compounds did not show intrinsic antimicrobial activity when tested alone. However, when used in combinations with CIP, a reversal in the antibacterial activity of CIP with up to 10-fold better MIC values was observed. In order to describe the binding site features of these BSN compounds with AcrB, docking studies were performed using the CDocker method. The performed docking poses and the calculated binding energy scores revealed that the tested compounds BSN-006, BSN-023, and BSN-004 showed significant binding interactions with the phenylalanine-rich region in the distal binding site of the AcrB binding monomer. Moreover, the tested compounds BSN-006 and BSN-023 possessed stronger binding energies than CIP, verifying that BSN compounds are acting as the putative substrates of AcrB.
Collapse
Affiliation(s)
- S Yilmaz
- a Pharmaceutical Chemistry Department, Faculty of Pharmacy , Ankara University , Ankara , Turkey
| | - G Altinkanat-Gelmez
- b Medical Microbiology Department, Faculty of Medicine , Marmara University , Istanbul , Turkey
| | - K Bolelli
- a Pharmaceutical Chemistry Department, Faculty of Pharmacy , Ankara University , Ankara , Turkey
| | - D Guneser-Merdan
- b Medical Microbiology Department, Faculty of Medicine , Marmara University , Istanbul , Turkey
| | - M Ufuk Over-Hasdemir
- b Medical Microbiology Department, Faculty of Medicine , Marmara University , Istanbul , Turkey
| | - E Aki-Yalcin
- a Pharmaceutical Chemistry Department, Faculty of Pharmacy , Ankara University , Ankara , Turkey
| | - I Yalcin
- a Pharmaceutical Chemistry Department, Faculty of Pharmacy , Ankara University , Ankara , Turkey
| |
Collapse
|
197
|
The efflux pump inhibitor timcodar improves the potency of antimycobacterial agents. Antimicrob Agents Chemother 2014; 59:1534-41. [PMID: 25534740 DOI: 10.1128/aac.04271-14] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previous studies indicated that inhibition of efflux pumps augments tuberculosis therapy. In this study, we used timcodar (formerly VX-853) to determine if this efflux pump inhibitor could increase the potency of antituberculosis (anti-TB) drugs against Mycobacterium tuberculosis in in vitro and in vivo combination studies. When used alone, timcodar weakly inhibited M. tuberculosis growth in broth culture (MIC, 19 μg/ml); however, it demonstrated synergism in drug combination studies with rifampin, bedaquiline, and clofazimine but not with other anti-TB agents. When M. tuberculosis was cultured in host macrophage cells, timcodar had about a 10-fold increase (50% inhibitory concentration, 1.9 μg/ml) in the growth inhibition of M. tuberculosis and demonstrated synergy with rifampin, moxifloxacin, and bedaquiline. In a mouse model of tuberculosis lung infection, timcodar potentiated the efficacies of rifampin and isoniazid, conferring 1.0 and 0.4 log10 reductions in bacterial burden in lung, respectively, compared to the efficacy of each drug alone. Furthermore, timcodar reduced the likelihood of a relapse infection when evaluated in a mouse model of long-term, chronic infection with treatment with a combination of rifampin, isoniazid, and timcodar. Although timcodar had no effect on the pharmacokinetics of rifampin in plasma and lung, it did increase the plasma exposure of bedaquiline. These data suggest that the antimycobacterial drug-potentiating activity of timcodar is complex and drug dependent and involves both bacterial and host-targeted mechanisms. Further study of the improvement of the potency of antimycobacterial drugs and drug candidates when used in combination with timcodar is warranted.
Collapse
|
198
|
Chen CW, Hsu CY, Lai SM, Syu WJ, Wang TY, Lai PS. Metal nanobullets for multidrug resistant bacteria and biofilms. Adv Drug Deliv Rev 2014; 78:88-104. [PMID: 25138828 DOI: 10.1016/j.addr.2014.08.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 06/27/2014] [Accepted: 08/11/2014] [Indexed: 12/19/2022]
Abstract
Infectious diseases were one of the major causes of mortality until now because drug-resistant bacteria have arisen under broad use and abuse of antibacterial drugs. These multidrug-resistant bacteria pose a major challenge to the effective control of bacterial infections and this threat has prompted the development of alternative strategies to treat bacterial diseases. Recently, use of metallic nanoparticles (NPs) as antibacterial agents is one of the promising strategies against bacterial drug resistance. This review first describes mechanisms of bacterial drug resistance and then focuses on the properties and applications of metallic NPs as antibiotic agents to deal with antibiotic-sensitive and -resistant bacteria. We also provide an overview of metallic NPs as bactericidal agents combating antibiotic-resistant bacteria and their potential in vivo toxicology for further drug development.
Collapse
Affiliation(s)
- Ching-Wen Chen
- Department of Chemistry, National Chung Hsing University, 250, Kuo Kuang Rd., Taichung 402, Taiwan
| | - Chia-Yen Hsu
- Department of Chemistry, National Chung Hsing University, 250, Kuo Kuang Rd., Taichung 402, Taiwan
| | - Syu-Ming Lai
- Department of Chemistry, National Chung Hsing University, 250, Kuo Kuang Rd., Taichung 402, Taiwan
| | - Wei-Jhe Syu
- Department of Chemistry, National Chung Hsing University, 250, Kuo Kuang Rd., Taichung 402, Taiwan
| | - Ting-Yi Wang
- Department of Chemistry, National Chung Hsing University, 250, Kuo Kuang Rd., Taichung 402, Taiwan
| | - Ping-Shan Lai
- Department of Chemistry, National Chung Hsing University, 250, Kuo Kuang Rd., Taichung 402, Taiwan; Research Center for Sustainable Energy and Nanotechnology, National Chung Hsing University, 250, Kuo Kuang Rd., Taichung 402, Taiwan.
| |
Collapse
|
199
|
Davis TD, Gerry CJ, Tan DS. General platform for systematic quantitative evaluation of small-molecule permeability in bacteria. ACS Chem Biol 2014; 9:2535-44. [PMID: 25198656 PMCID: PMC4245172 DOI: 10.1021/cb5003015] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The chemical features that impact small-molecule permeability across bacterial membranes are poorly understood, and the resulting lack of tools to predict permeability presents a major obstacle to the discovery and development of novel antibiotics. Antibacterials are known to have vastly different structural and physicochemical properties compared to nonantiinfective drugs, as illustrated herein by principal component analysis (PCA). To understand how these properties influence bacterial permeability, we have developed a systematic approach to evaluate the penetration of diverse compounds into bacteria with distinct cellular envelopes. Intracellular compound accumulation is quantitated using LC-MS/MS, then PCA and Pearson pairwise correlations are used to identify structural and physicochemical parameters that correlate with accumulation. An initial study using 10 sulfonyladenosines in Escherichia coli, Bacillus subtilis, and Mycobacterium smegmatis has identified nonobvious correlations between chemical structure and permeability that differ among the various bacteria. Effects of cotreatment with efflux pump inhibitors were also investigated. This sets the stage for use of this platform in larger prospective analyses of diverse chemotypes to identify global relationships between chemical structure and bacterial permeability that would enable the development of predictive tools to accelerate antibiotic drug discovery.
Collapse
Affiliation(s)
- Tony D. Davis
- Pharmacology Program−Weill Cornell Graduate School of Medical Sciences, ‡Gerstner Sloan Kettering Summer Undergraduate Research Program, §Molecular Pharmacology & Chemistry Program and Tri-Institutional Research Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Box 422, New York, New York 10065, United States
| | - Christopher J. Gerry
- Pharmacology Program−Weill Cornell Graduate School of Medical Sciences, ‡Gerstner Sloan Kettering Summer Undergraduate Research Program, §Molecular Pharmacology & Chemistry Program and Tri-Institutional Research Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Box 422, New York, New York 10065, United States
| | - Derek S. Tan
- Pharmacology Program−Weill Cornell Graduate School of Medical Sciences, ‡Gerstner Sloan Kettering Summer Undergraduate Research Program, §Molecular Pharmacology & Chemistry Program and Tri-Institutional Research Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Box 422, New York, New York 10065, United States
| |
Collapse
|
200
|
Heo A, Jang HJ, Sung JS, Park W. Global transcriptome and physiological responses of Acinetobacter oleivorans DR1 exposed to distinct classes of antibiotics. PLoS One 2014; 9:e110215. [PMID: 25330344 PMCID: PMC4201530 DOI: 10.1371/journal.pone.0110215] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 09/09/2014] [Indexed: 11/18/2022] Open
Abstract
The effects of antibiotics on environment-originated nonpathogenic Acinetobacter species have been poorly explored. To understand the antibiotic-resistance mechanisms that function in nonpathogenic Acinetobacter species, we used an RNA-sequencing (RNA-seq) technique to perform global gene-expression profiling of soil-borne Acinetobacter oleivorans DR1 after exposing the bacteria to 4 classes of antibiotics (ampicillin, Amp; kanamycin, Km; tetracycline, Tc; norfloxacin, Nor). Interestingly, the well-known two global regulators, the soxR and the rpoE genes are present among 41 commonly upregulated genes under all 4 antibiotic-treatment conditions. We speculate that these common genes are essential for antibiotic resistance in DR1. Treatment with the 4 antibiotics produced diverse physiological and phenotypic changes. Km treatment induced the most dramatic phenotypic changes. Examination of mutation frequency and DNA-repair capability demonstrated the induction of the SOS response in Acinetobacter especially under Nor treatment. Based on the RNA-seq analysis, the glyoxylate-bypass genes of the citrate cycle were specifically upregulated under Amp treatment. We also identified newly recognized non-coding small RNAs of the DR1 strain, which were also confirmed by Northern blot analysis. These results reveal that treatment with antibiotics of distinct classes differentially affected the gene expression and physiology of DR1 cells. This study expands our understanding of the molecular mechanisms of antibiotic-stress response of environment-originated bacteria and provides a basis for future investigations.
Collapse
Affiliation(s)
- Aram Heo
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Hyun-Jin Jang
- Department of Life Science, Dongguk University, Seoul, Republic of Korea
| | - Jung-Suk Sung
- Department of Life Science, Dongguk University, Seoul, Republic of Korea
| | - Woojun Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
- * E-mail:
| |
Collapse
|