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Zhang H, Mou J, Ding J, Qin W. Rapid antibiotic screening based on E. coli apoptosis using a potentiometric sensor array. Anal Chim Acta 2024; 1297:342378. [PMID: 38438244 DOI: 10.1016/j.aca.2024.342378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 02/12/2024] [Accepted: 02/13/2024] [Indexed: 03/06/2024]
Abstract
Phenotypic antimicrobial susceptibility testing enables reliable antibiotic screening but requires multiple strategies to identify each phenotypic change induced by different bactericidal mechanisms. Bacteria apoptosis with typical phenotypic features has never been explored for antibiotic screening. Herein, we developed an antibiotic screening method based on the measurement of antibiotic-induced phosphatidylserine (PS) exposure of apoptotic bacteria. Phosphatidylserine externalization of E. coli that can be widely used as an apoptosis marker for antibiotics with different antibacterial mechanisms was explored. A positively charged PS-binding peptide was immobilized on magnetic beads (MBs) to recognize and capture apoptotic E. coli with PS externalization. Apoptotic E. coli binding led to the charge or charge density change of MBs-peptide, resulting in a potential change on a magneto-controlled polymeric membrane potentiometric sensor. Based on the detection of apoptotic E. coli killed by antibiotics, antibiotic screening for different classes of antibiotics and silver nanoparticles was achieved within 1.5 h using a potentiometric sensor array. This approach enables sensitive, general, and time-saving antibiotic screening, and may open up a new path for antibiotic susceptibility testing.
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Affiliation(s)
- Han Zhang
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong, 264003, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Junsong Mou
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong, 264003, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Jiawang Ding
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong, 264003, PR China; Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong, 266237, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, Shandong, 266071, PR China.
| | - Wei Qin
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong, 264003, PR China; Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong, 266237, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, Shandong, 266071, PR China
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2
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Karampatakis T, Tsergouli K, Behzadi P. Pan-Genome Plasticity and Virulence Factors: A Natural Treasure Trove for Acinetobacter baumannii. Antibiotics (Basel) 2024; 13:257. [PMID: 38534692 DOI: 10.3390/antibiotics13030257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 02/17/2024] [Accepted: 03/12/2024] [Indexed: 03/28/2024] Open
Abstract
Acinetobacter baumannii is a Gram-negative pathogen responsible for a variety of community- and hospital-acquired infections. It is recognized as a life-threatening pathogen among hospitalized individuals and, in particular, immunocompromised patients in many countries. A. baumannii, as a member of the ESKAPE group, encompasses high genomic plasticity and simultaneously is predisposed to receive and exchange the mobile genetic elements (MGEs) through horizontal genetic transfer (HGT). Indeed, A. baumannii is a treasure trove that contains a high number of virulence factors. In accordance with these unique pathogenic characteristics of A. baumannii, the authors aim to discuss the natural treasure trove of pan-genome and virulence factors pertaining to this bacterial monster and try to highlight the reasons why this bacterium is a great concern in the global public health system.
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Affiliation(s)
| | - Katerina Tsergouli
- Microbiology Department, Agios Pavlos General Hospital, 55134 Thessaloniki, Greece
| | - Payam Behzadi
- Department of Microbiology, Shahr-e-Qods Branch, Islamic Azad University, Tehran 37541-374, Iran
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3
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Abstract
Gram-negative bacteria are intrinsically resistant to many antibiotics, due in large part to the permeability barrier formed by their cell envelope. The complex and synergistic interplay of the two Gram-negative membranes and active efflux prevents the accumulation of a diverse range of compounds that are effective against Gram-positive bacteria. A lack of detailed information on how components of the cell envelope contribute to this has been identified as a key barrier to the rational development of new antibiotics with efficacy against Gram-negative species. This review describes the current understanding of the role of the different components of the Gram-negative cell envelope in preventing compound accumulation and the state of efforts to describe properties that allow compounds to overcome this barrier and apply them to the development of new broad-spectrum antibiotics.
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Affiliation(s)
- Claire Maher
- College of Engineering, Science and Environment, University of Newcastle, Newcastle, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, Australia
| | - Karl A. Hassan
- College of Engineering, Science and Environment, University of Newcastle, Newcastle, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, Australia
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4
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Yao Y, Chen Q, Zhou H. Virulence Factors and Pathogenicity Mechanisms of Acinetobacter baumannii in Respiratory Infectious Diseases. Antibiotics (Basel) 2023; 12:1749. [PMID: 38136783 PMCID: PMC10740465 DOI: 10.3390/antibiotics12121749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/14/2023] [Accepted: 12/16/2023] [Indexed: 12/24/2023] Open
Abstract
Acinetobacter baumannii (A. baumannii) has become a notorious pathogen causing nosocomial and community-acquired infections, especially ventilator-associated pneumonia. This opportunistic pathogen is found to possess powerful genomic plasticity and numerous virulence factors that facilitate its success in the infectious process. Although the interactions between A. baumannii and the pulmonary epitheliums have been extensively studied, a complete and specific description of its overall pathogenic process is lacking. In this review, we summarize the current knowledge of the antibiotic resistance and virulence factors of A. baumannii, specifically focusing on the pathogenic mechanisms of this detrimental pathogen in respiratory infectious diseases. An expansion of the knowledge regarding A. baumannii pathogenesis will contribute to the development of effective therapies based on immunopathology or intracellular signaling pathways to eliminate this harmful pathogen during infections.
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Affiliation(s)
| | | | - Hua Zhou
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China; (Y.Y.); (Q.C.)
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5
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Bodrenko I, Ceccarelli M, Acosta-Gutierrez S. The mechanism of an electrostatic nanofilter: overcoming entropy with electrostatics. Phys Chem Chem Phys 2023; 25:26497-26506. [PMID: 37772905 DOI: 10.1039/d3cp02895j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
General porins are nature's sieving machinery in the outer membrane of Gram-negative bacteria. Their unique hourglass-shaped architecture is highly conserved among different bacterial membrane proteins and other biological channels. These biological nanopores have been designed to protect the interior of the bacterial cell from leakage of toxic compounds while selectively allowing the entry of the molecules needed for cell growth and function. The mechanism of transport through porins is of utmost and direct interest for drug discovery, extending toward nanotechnology applications for blue energy, separations, and sequencing. Here we present a theoretical framework for analysing the filter of general porins in relation to translocating molecules with the aid of enhanced molecular simulations quantitatively. Using different electrostatic probes in the form of a series of related molecules, we describe the nature of this filter and how to finely tune permeability by exploiting electrostatic interactions between the pore and the translocating molecule. Eventually, we show how enhanced simulations constitute today a valid tool for characterising the mechanism and quantifying energetically the transport of molecules through nanopores.
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Affiliation(s)
- Igor Bodrenko
- École Normale Supérieure, Département de Chimie - Laboratoire PASTEUR, Paris, France
- CNR-IOM, Sezione di Cagliari, Cittadella Universitaria di Monserrato, S.P.8 - km 0.700, 09042 Monserrato (CA), Italy
| | - Matteo Ceccarelli
- CNR-IOM, Sezione di Cagliari, Cittadella Universitaria di Monserrato, S.P.8 - km 0.700, 09042 Monserrato (CA), Italy
- Department of Physics, University of Cagliari, Cittadella Universitaria di Monserrato, S.P.8 - km 0.700, 09042 Monserrato (CA), Italy.
| | - Silvia Acosta-Gutierrez
- Institute for Bioengineering of Catalonia, Carrer Baldiri Reixac 10-12, 080028 Barcelona, Spain.
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6
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Sass AM, Coenye T. The Small RNA NcS25 Regulates Biological Amine-Transporting Outer Membrane Porin BCAL3473 in Burkholderia cenocepacia. mSphere 2023; 8:e0008323. [PMID: 36971554 PMCID: PMC10117139 DOI: 10.1128/msphere.00083-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 03/03/2023] [Indexed: 03/29/2023] Open
Abstract
Regulation of porin expression in bacteria is complex and often involves small-RNA regulators. Several small-RNA regulators have been described for Burkholderia cenocepacia, and this study aimed to characterize the biological role of the conserved small RNA NcS25 and its cognate target, outer membrane protein BCAL3473. The B. cenocepacia genome carries a large number of genes encoding porins with yet-uncharacterized functions. Expression of the porin BCAL3473 is strongly repressed by NcS25 and activated by other factors, such as a LysR-type regulator and nitrogen-depleted growth conditions. The porin is involved in transport of arginine, tyrosine, tyramine, and putrescine across the outer membrane. Porin BCAL3473, with NcS25 as a major regulator, plays an important role in the nitrogen metabolism of B. cenocepacia. IMPORTANCE Burkholderia cenocepacia is a Gram-negative bacterium which causes infections in immunocompromised individuals and in people with cystic fibrosis. A low outer membrane permeability is one of the factors giving it a high level of innate resistance to antibiotics. Porins provide selective permeability for nutrients, and antibiotics can also traverse the outer membrane by this means. Knowing the properties and specificities of porin channels is therefore important for understanding resistance mechanisms and for developing new antibiotics and could help in overcoming permeability issues in antibiotic treatment.
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Affiliation(s)
- Andrea M. Sass
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
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7
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Ebrahimi A, Ergün T, Kaygusuz İzgördü Ö, Darcan C, Avci H, Öztürk B, Güner HR, Ghorbanpoor H, Doğan Güzel F. Revealing the single-channel characteristics of OprD (OccAB1) porins from hospital strains of Acinetobacter baumannii. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2023:10.1007/s00249-023-01651-2. [PMID: 37052656 DOI: 10.1007/s00249-023-01651-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 03/28/2023] [Accepted: 04/07/2023] [Indexed: 04/14/2023]
Abstract
Nowadays, reports of antimicrobial resistance (AMR) against many antibiotics are increasing because of their misapplication. With this rise, there is a serious decrease in the discovery and development of new types of antibiotics amid an increase in multi-drug resistance. Unfermented Acinetobacter baumannii from gram-negative bacteria, which is one of the main causes of nosocomial infections and multi-drug resistance, has 4 main kinds of antibiotic resistance mechanism: inactivating antibiotics by enzymes, reduced numbers of porins and changing of their target or cellular functions due to mutations, and efflux pumps. In this study, characterization of the possible mutations in OprD (OccAB1) porins from hospital strains of A. baumannii were investigated using single channel electrophysiology and compared with the standard OprD isolated from wild type ATCC 19,606. For this aim, 5 A. baumannii bacteria samples were obtained from patients infected with A. baumannii, after which OprD porins were isolated from these A. baumannii strains. OprD porins were then inserted in an artificial lipid bilayer and the current-voltage curves were obtained using electrical recordings through a pair of Ag/AgCl electrodes. We observed that each porin has a characteristic conductance and single channel recording, which then leads to differences in channel diameter. Finally, the single channel data have been compared with the gene sequences of each porin. It was interesting to find out that each porin isolated has a unique porin diameter and decreased anion selectivity compared to the wild type.
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Affiliation(s)
- Aliakbar Ebrahimi
- Faculty of Engineering and Natural Sciences, Department of Biomedical Engineering, Ankara Yildirim Beyazit University, Ankara, Turkey
- Cellular Therapy and Stem Cell Research Center and Translational Medicine Research and Clinical Center (ESTEM), Eskisehir Osmangazi University, Eskisehir, Turkey
| | - Tuğçe Ergün
- Faculty of Engineering and Natural Sciences, Department of Biomedical Engineering, Ankara Yildirim Beyazit University, Ankara, Turkey
- Department of Biotechnology and Biosafety, Eskisehir Osmangazi University, Eskisehir, Turkey
| | - Özge Kaygusuz İzgördü
- Biotechnology Application and Research Center, Bilecik Şeyh Edebali University, Bilecik, Turkey
| | - Cihan Darcan
- Faculty of Science and Literature, Department of Molecular Biology and Genetics, Bilecik Seyh Edebali University, Bilecik, Turkey
| | - Hüseyin Avci
- Cellular Therapy and Stem Cell Research Center and Translational Medicine Research and Clinical Center (ESTEM), Eskisehir Osmangazi University, Eskisehir, Turkey
- Faculty of Engineering and Architecture, Department of Metallurgical and Material Engineering, Eskisehir Osmangazi University, Eskisehir, Turkey
- Department of Stem Cell, Institute of Health Sciences, Eskisehir Osmangazi University, Eskisehir, Turkey
- Translational Medicine Research and Clinical Center (TATUM), Eskisehir Osmangazi University, Eskisehir, Turkey
| | - Barçin Öztürk
- Faculty of Medicine, Department of Infectious Diseases and Clinical Microbiology, Adnan Menderes University, Aydin, Turkey
| | - Hatice Rahmet Güner
- Faculty of Medicine, Department of Infectious Diseases and Clinical Microbiology, Ankara Yildirim Beyazit University, Ankara, Turkey
| | - Hamed Ghorbanpoor
- Cellular Therapy and Stem Cell Research Center and Translational Medicine Research and Clinical Center (ESTEM), Eskisehir Osmangazi University, Eskisehir, Turkey
- Department of Biomedical Engineering, Eskisehir Osmangazi University, Eskisehir, Turkey
| | - Fatma Doğan Güzel
- Faculty of Engineering and Natural Sciences, Department of Biomedical Engineering, Ankara Yildirim Beyazit University, Ankara, Turkey.
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8
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Shadan A, Pathak A, Ma Y, Pathania R, Singh RP. Deciphering the virulence factors, regulation, and immune response to Acinetobacter baumannii infection. Front Cell Infect Microbiol 2023; 13:1053968. [PMID: 36968113 PMCID: PMC10038080 DOI: 10.3389/fcimb.2023.1053968] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 02/06/2023] [Indexed: 02/25/2023] Open
Abstract
Deciphering the virulence factors, regulation, and immune response to Acinetobacter baumannii infectionAcinetobacter baumannii is a gram-negative multidrug-resistant nosocomial pathogen and a major cause of hospital acquired infetions. Carbapenem resistant A. baumannii has been categorised as a Priority1 critial pathogen by the World Health Organisation. A. baumannii is responsible for infections in hospital settings, clinical sectors, ventilator-associated pneumonia, and bloodstream infections with a mortality rates up to 35%. With the development of advanced genome sequencing, molecular mechanisms of manipulating bacterial genomes, and animal infection studies, it has become more convenient to identify the factors that play a major role in A. baumannii infection and its persistence. In the present review, we have explored the mechanism of infection, virulence factors, and various other factors associated with the pathogenesis of this organism. Additionally, the role of the innate and adaptive immune response, and the current progress in the development of innovative strategies to combat this multidrug-resistant pathogen is also discussed.
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Affiliation(s)
- Afreen Shadan
- Department of Microbiology, Dr. Shyama Prasad Mukherjee University, Ranchi, Jharkhand, India
| | - Avik Pathak
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India
| | - Ying Ma
- College of Resources and Environment, Southwest University, Chongqing, China
- *Correspondence: Ying Ma, ; Ranjana Pathania, ; Rajnish Prakash Singh,
| | - Ranjana Pathania
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India
- *Correspondence: Ying Ma, ; Ranjana Pathania, ; Rajnish Prakash Singh,
| | - Rajnish Prakash Singh
- Department of Bioengineering and Biotechnology, Birla Institute of Technology, Ranchi, Jharkhand, India
- *Correspondence: Ying Ma, ; Ranjana Pathania, ; Rajnish Prakash Singh,
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9
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Zhu T, Lei Z, Qu S, Zhao F, Yan L, Chen M, Zhou XW, Di Q, Zhao Y. Comparison of the outer membrane proteomes between clinical carbapenem-resistant and susceptible Acinetobacter baumannii. Lett Appl Microbiol 2022; 74:873-882. [PMID: 35138649 DOI: 10.1111/lam.13672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 02/03/2022] [Accepted: 02/06/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND AIM Carbapenem resistance has become a major obstacle in combating Acinetobacter baumannii infections. Although enzymatic degradation by β-lactamases is the pivotal mechanism of carbapenem resistance, porin deficiency has also been implicated in the mechanism. In this study, outer membrane proteins (OMPs) pattern of a clinical multidrug-resistant A. baumannii isolate were analyzed in order to attain a deeper understanding of carbapenem resistance strategies. METHODS OMPs extracts respectively separated from carbapenem-resistant and -susceptible clinical A. baumannii isolates were compared using two-dimensional polyacrylamide gel electrophoresis. Differentially expressed proteins were identified by matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF). RESULTS Twenty-three differently expressed proteins were identified between the resistant and susceptible isolates. Among them, six were annotated convincingly as OMPs in UniProt database. CarO was found absent from the resistant isolate and the expression levels of Omp33-36 and Omp25 were significantly lower than that in the susceptible counterpart. Strikingly, a LysM domain/BON superfamily protein, which has been linked to carbapenem resistance in Klebsiella pneumoniae, was found underexpressed by 10-fold in the resistant isolate. CONCLUSION Our study verified some porins which have been proven to play an important role in bacterial resistance against carbapenems. Underexpression of the LysM domain/BON superfamily protein may indicate its possible engagement in bacterial drug resistance, but its actual role requires more investigation.
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Affiliation(s)
- Tao Zhu
- Department of Medical Microbiology and Immunology, Wannan Medical College, Wuhu, 241002, PR China
| | - Zhongying Lei
- Department of Laboratory Medicine, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, 210011, PR China
| | - Su Qu
- Shanghai Vitalgen BioPharma Co, Ltd, Shanghai, 201108, PR China
| | - Fuju Zhao
- Institute of Medical Microbiology and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, 200032, PR China
| | - Liang Yan
- Institute of Medical Microbiology and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, 200032, PR China
| | - Mingliang Chen
- Department of Microbiology, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, 200336, PR China
| | - Xin Wen Zhou
- Institute of Medical Microbiology and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, 200032, PR China
| | - Qu Di
- Institute of Medical Microbiology and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, 200032, PR China
| | - Yanfeng Zhao
- Department of Laboratory Medicine, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, 210011, PR China
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10
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Takebayashi Y, Findlay J, Heesom KJ, Warburton PJ, Avison MB, Evans BA. Variability in carbapenemase activity of intrinsic OxaAb (OXA-51-like) β-lactamase enzymes in Acinetobacter baumannii. J Antimicrob Chemother 2021; 76:587-595. [PMID: 33338207 DOI: 10.1093/jac/dkaa502] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 11/03/2020] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES To measure the variability in carbapenem susceptibility conferred by different OxaAb variants, characterize the molecular evolution of oxaAb and elucidate the contribution of OxaAb and other possible carbapenem resistance factors in the clinical isolates using WGS and LC-MS/MS. METHODS Antimicrobial susceptibility tests were performed on 10 clinical Acinetobacter baumannii isolates. Carbapenem MICs were evaluated for all oxaAb variants cloned into A. baumannii CIP70.10 and BM4547, with and without their natural promoters. Molecular evolution analysis of the oxaAb variants was performed using FastTree and SplitsTree4. Resistance determinants were studied in the clinical isolates using WGS and LC-MS/MS. RESULTS Only the OxaAb variants with I129L and L167V substitutions, OxaAb(82), OxaAb(83), OxaAb(107) and OxaAb(110) increased carbapenem MICs when expressed in susceptible A. baumannii backgrounds without an upstream IS element. Carbapenem resistance was conferred with the addition of their natural upstream ISAba1 promoter. LC-MS/MS analysis on the original clinical isolates confirmed overexpression of the four I129L and L167V variants. No other differences in expression levels of proteins commonly associated with carbapenem resistance were detected. CONCLUSIONS Elevated carbapenem MICs were observed by expression of OxaAb variants carrying clinically prevalent substitutions I129L and L167V. To drive carbapenem resistance, these variants required overexpression by their upstream ISAba1 promoter. This study clearly demonstrates that a combination of IS-driven overexpression of oxaAb and the presence of particular amino acid substitutions in the active site to improve carbapenem capture is key in conferring carbapenem resistance in A. baumannii and other mechanisms are not required.
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Affiliation(s)
- Yuiko Takebayashi
- Department of Biomedical and Forensic Science, Anglia Ruskin University, Cambridge, UK.,School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Jacqueline Findlay
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK.,Division of Infection & Immunity, Faculty of Medical Sciences, University College London, UK
| | - Kate J Heesom
- Bristol Proteomics Facility, University of Bristol, Bristol, UK
| | - Philip J Warburton
- Department of Biomedical and Forensic Science, Anglia Ruskin University, Cambridge, UK.,School of Biomedical Sciences, Faculty of Health, University of Plymouth, Plymouth, UK
| | - Matthew B Avison
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Benjamin A Evans
- Department of Biomedical and Forensic Science, Anglia Ruskin University, Cambridge, UK.,Norwich Medical School, University of East Anglia, UK
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Mastering the Gram-negative bacterial barrier - Chemical approaches to increase bacterial bioavailability of antibiotics. Adv Drug Deliv Rev 2021; 172:339-360. [PMID: 33705882 DOI: 10.1016/j.addr.2021.02.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 02/08/2021] [Accepted: 02/18/2021] [Indexed: 02/07/2023]
Abstract
To win the battle against resistant, pathogenic bacteria, novel classes of anti-infectives and targets are urgently needed. Bacterial uptake, distribution, metabolic and efflux pathways of antibiotics in Gram-negative bacteria determine what we here refer to as bacterial bioavailability. Understanding these mechanisms from a chemical perspective is essential for anti-infective activity and hence, drug discovery as well as drug delivery. A systematic and critical discussion of in bacterio, in vitro and in silico assays reveals that a sufficiently accurate holistic approach is still missing. We expect new findings based on Gram-negative bacterial bioavailability to guide future anti-infective research.
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12
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Acinetobacter baumannii: An Ancient Commensal with Weapons of a Pathogen. Pathogens 2021; 10:pathogens10040387. [PMID: 33804894 PMCID: PMC8063835 DOI: 10.3390/pathogens10040387] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 12/22/2022] Open
Abstract
Acinetobacter baumannii is regarded as a life-threatening pathogen associated with community-acquired and nosocomial infections, mainly pneumonia. The rise in the number of A. baumannii antibiotic-resistant strains reduces effective therapies and increases mortality. Bacterial comparative genomic studies have unraveled the innate and acquired virulence factors of A. baumannii. These virulence factors are involved in antibiotic resistance, environmental persistence, host-pathogen interactions, and immune evasion. Studies on host–pathogen interactions revealed that A. baumannii evolved different mechanisms to adhere to in order to invade host respiratory cells as well as evade the host immune system. In this review, we discuss current data on A. baumannii genetic features and virulence factors. An emphasis is given to the players in host–pathogen interaction in the respiratory tract. In addition, we report recent investigations into host defense systems using in vitro and in vivo models, providing new insights into the innate immune response to A. baumannii infections. Increasing our knowledge of A. baumannii pathogenesis may help the development of novel therapeutic strategies based on anti-adhesive, anti-virulence, and anti-cell to cell signaling pathways drugs.
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13
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Acinetobacter baumannii Antibiotic Resistance Mechanisms. Pathogens 2021; 10:pathogens10030373. [PMID: 33808905 PMCID: PMC8003822 DOI: 10.3390/pathogens10030373] [Citation(s) in RCA: 190] [Impact Index Per Article: 63.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 03/16/2021] [Accepted: 03/18/2021] [Indexed: 12/11/2022] Open
Abstract
Acinetobacter baumannii is a Gram-negative ESKAPE microorganism that poses a threat to public health by causing severe and invasive (mostly nosocomial) infections linked with high mortality rates. During the last years, this pathogen displayed multidrug resistance (MDR), mainly due to extensive antibiotic abuse and poor stewardship. MDR isolates are associated with medical history of long hospitalization stays, presence of catheters, and mechanical ventilation, while immunocompromised and severely ill hosts predispose to invasive infections. Next-generation sequencing techniques have revolutionized diagnosis of severe A. baumannii infections, contributing to timely diagnosis and personalized therapeutic regimens according to the identification of the respective resistance genes. The aim of this review is to describe in detail all current knowledge on the genetic background of A. baumannii resistance mechanisms in humans as regards beta-lactams (penicillins, cephalosporins, carbapenems, monobactams, and beta-lactamase inhibitors), aminoglycosides, tetracyclines, fluoroquinolones, macrolides, lincosamides, streptogramin antibiotics, polymyxins, and others (amphenicols, oxazolidinones, rifamycins, fosfomycin, diaminopyrimidines, sulfonamides, glycopeptide, and lipopeptide antibiotics). Mechanisms of antimicrobial resistance refer mainly to regulation of antibiotic transportation through bacterial membranes, alteration of the antibiotic target site, and enzymatic modifications resulting in antibiotic neutralization. Virulence factors that may affect antibiotic susceptibility profiles and confer drug resistance are also being discussed. Reports from cases of A. baumannii coinfection with SARS-CoV-2 during the COVID-19 pandemic in terms of resistance profiles and MDR genes have been investigated.
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14
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Prajapati JD, Kleinekathöfer U, Winterhalter M. How to Enter a Bacterium: Bacterial Porins and the Permeation of Antibiotics. Chem Rev 2021; 121:5158-5192. [PMID: 33724823 DOI: 10.1021/acs.chemrev.0c01213] [Citation(s) in RCA: 100] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Despite tremendous successes in the field of antibiotic discovery seen in the previous century, infectious diseases have remained a leading cause of death. More specifically, pathogenic Gram-negative bacteria have become a global threat due to their extraordinary ability to acquire resistance against any clinically available antibiotic, thus urging for the discovery of novel antibacterial agents. One major challenge is to design new antibiotics molecules able to rapidly penetrate Gram-negative bacteria in order to achieve a lethal intracellular drug accumulation. Protein channels in the outer membrane are known to form an entry route for many antibiotics into bacterial cells. Up until today, there has been a lack of simple experimental techniques to measure the antibiotic uptake and the local concentration in subcellular compartments. Hence, rules for translocation directly into the various Gram-negative bacteria via the outer membrane or via channels have remained elusive, hindering the design of new or the improvement of existing antibiotics. In this review, we will discuss the recent progress, both experimentally as well as computationally, in understanding the structure-function relationship of outer-membrane channels of Gram-negative pathogens, mainly focusing on the transport of antibiotics.
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Affiliation(s)
| | | | - Mathias Winterhalter
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen 28759, Germany
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15
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Ozturk Y, Ebrahimi A, Norouz Dizaji A, Kaygusuz O, Bafna JA, Winterhalter M, Cankaya G, Darcan C, Dogan Guzel F. Rapid fabrication of teflon apertures by controlled high voltage pulses for formation of free standing planar lipid bilayer membrane. Biomed Microdevices 2021; 23:12. [PMID: 33638734 DOI: 10.1007/s10544-021-00553-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2021] [Indexed: 11/29/2022]
Abstract
Free standing artificial lipid bilayers are widely used in the study of biological pores. In these types of studies, the free standing planar lipid bilayer is formed over a micron-sized aperture consisting of either polymer such as Polytetrafluoroethylene (PTFE, Teflon) or glass. Teflon is chemically inert, has a low dielectric constant, and has a high electrical resistance which combined allow for obtaining low noise recordings. This study investigates the reproducible generation of micropores in the range of 50-100 microns in diameter in a Teflon film using a high energy discharge set-up. The discharger set-up consists of a microprocessor, a transformer, a voltage regulator, and is controlled by a computer. We compared two approaches for pore creation: single and multi-pulse methods. The results showed that the multi-pulse method produced narrower aperture size distributions and is more convenient for lipid bilayer formation, and thus would have a higher success rate than the single-pulse method. The bilayer stability experiments showed that the lipid bilayer lasts for more than 33 h. Finally, as a proof-of-concept, we show that the single and multi-channel electrophysiology experiments were successfully performed with the apertures created by using the mentioned discharger. In conclusion, the described discharger provides reproducible Teflon-pores in a cheap and easy-to-operate manner.
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Affiliation(s)
- Yasin Ozturk
- Department of Metallurgical and Materials Engineering, Ankara Yıldırım Beyazıt University, Ankara, Turkey
| | - Aliakbar Ebrahimi
- Department of Biomedical Engineering, Ankara Yıldırım Beyazıt University, Ankara, Turkey
| | - Araz Norouz Dizaji
- Department of Biomedical Engineering, Ankara Yıldırım Beyazıt University, Ankara, Turkey
| | - Ozge Kaygusuz
- Biotechnology Application and Research Center, Bilecik Seyh Edebali University, Bilecik, Turkey
| | - Jayesh Arun Bafna
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen, Germany
| | - Mathias Winterhalter
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen, Germany
| | - Guven Cankaya
- Department of Metallurgical and Materials Engineering, Ankara Yıldırım Beyazıt University, Ankara, Turkey
| | - Cihan Darcan
- Biotechnology Application and Research Center, Bilecik Seyh Edebali University, Bilecik, Turkey.,Department of Molecular Biology and Genetics, Bilecik Seyh Edebali University, Bilecik, Turkey
| | - Fatma Dogan Guzel
- Department of Biomedical Engineering, Ankara Yıldırım Beyazıt University, Ankara, Turkey.
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16
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Kurihara MNL, de Sales RO, da Silva KE, Maciel WG, Simionatto S. Multidrug-resistant Acinetobacter baumannii outbreaks: a global problem in healthcare settings. Rev Soc Bras Med Trop 2020; 53:e20200248. [PMID: 33174956 PMCID: PMC7670754 DOI: 10.1590/0037-8682-0248-2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 09/02/2020] [Indexed: 12/26/2022] Open
Abstract
INTRODUCTION The increase in the prevalence of multidrug-resistant Acinetobacter baumannii infections in hospital settings has rapidly emerged worldwide as a serious health problem. METHODS This review synthetizes the epidemiology of multidrug-resistant A. baumannii, highlighting resistance mechanisms. CONCLUSIONS Understanding the genetic mechanisms of resistance as well as the associated risk factors is critical to develop and implement adequate measures to control and prevent acquisition of nosocomial infections, especially in an intensive care unit setting.
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Affiliation(s)
| | - Romário Oliveira de Sales
- Universidade Federal da Grande Dourados, Laboratório de Pesquisa
em Ciências da Saúde, Dourados, MS, Brasil
| | - Késia Esther da Silva
- Universidade Federal da Grande Dourados, Laboratório de Pesquisa
em Ciências da Saúde, Dourados, MS, Brasil
| | - Wirlaine Glauce Maciel
- Universidade Federal da Grande Dourados, Laboratório de Pesquisa
em Ciências da Saúde, Dourados, MS, Brasil
| | - Simone Simionatto
- Universidade Federal da Grande Dourados, Laboratório de Pesquisa
em Ciências da Saúde, Dourados, MS, Brasil
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17
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Uppalapati SR, Sett A, Pathania R. The Outer Membrane Proteins OmpA, CarO, and OprD of Acinetobacter baumannii Confer a Two-Pronged Defense in Facilitating Its Success as a Potent Human Pathogen. Front Microbiol 2020; 11:589234. [PMID: 33123117 PMCID: PMC7573547 DOI: 10.3389/fmicb.2020.589234] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/11/2020] [Indexed: 12/12/2022] Open
Abstract
Of all the ESKAPE pathogens, carbapenem-resistant and multidrug-resistant Acinetobacter baumannii is the leading cause of hospital-acquired and ventilator-associated pneumonia. A. baumannii infections are notoriously hard to eradicate due to its propensity to rapidly acquire multitude of resistance determinants and the virulence factor cornucopia elucidated by the bacterium that help it fend off a wide range of adverse conditions imposed upon by host and environment. One such weapon in the arsenal of A. baumannii is the outer membrane protein (OMP) compendium. OMPs in A. baumannii play distinctive roles in facilitating the bacterial acclimatization to antibiotic- and host-induced stresses, albeit following entirely different mechanisms. OMPs are major immunogenic proteins in bacteria conferring bacteria host-fitness advantages including immune evasion, stress tolerance, and resistance to antibiotics and antibacterials. In this review, we summarize the current knowledge of major A. baumannii OMPs and discuss their versatile role in antibiotic resistance and virulence. Specifically, we explore how OmpA, CarO, and OprD-like porins mediate antibiotic and amino acid shuttle and host virulence.
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Affiliation(s)
- Siva R Uppalapati
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, India
| | - Abhiroop Sett
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, India
| | - Ranjana Pathania
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, India
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18
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Zgurskaya HI, Rybenkov VV. Permeability barriers of Gram-negative pathogens. Ann N Y Acad Sci 2020; 1459:5-18. [PMID: 31165502 PMCID: PMC6940542 DOI: 10.1111/nyas.14134] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/06/2019] [Accepted: 05/13/2019] [Indexed: 12/13/2022]
Abstract
Most clinical antibiotics do not have efficacy against Gram-negative pathogens, mainly because these cells are protected by the permeability barrier comprising the two membranes with active efflux. The emergence of multidrug-resistant Gram-negative strains threatens the utility even of last resort therapeutic treatments. Significant efforts at different levels of resolution are currently focused on finding a solution to this nonpermeation problem and developing new approaches to the optimization of drug activities against multidrug-resistant pathogens. The exceptional efficiency of the Gram-negative permeability barrier is the result of a complex interplay between the two opposing fluxes of drugs across the two membranes. In this review, we describe the current state of understanding of the problem and the recent advances in theoretical and empirical approaches to characterization of drug permeation and active efflux in Gram-negative bacteria.
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Affiliation(s)
- Helen I Zgurskaya
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma
| | - Valentin V Rybenkov
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma
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19
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Annunziato G. Strategies to Overcome Antimicrobial Resistance (AMR) Making Use of Non-Essential Target Inhibitors: A Review. Int J Mol Sci 2019; 20:E5844. [PMID: 31766441 PMCID: PMC6928725 DOI: 10.3390/ijms20235844] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/19/2019] [Accepted: 11/20/2019] [Indexed: 12/23/2022] Open
Abstract
Antibiotics have always been considered as one of the most relevant discoveries of the twentieth century. Unfortunately, the dawn of the antibiotic era has sadly corresponded to the rise of the phenomenon of antimicrobial resistance (AMR), which is a natural process whereby microbes evolve in such a way to withstand the action of drugs. In this context, the identification of new potential antimicrobial targets and/or the identification of new chemical entities as antimicrobial drugs are in great demand. To date, among the many possible approaches used to deal with antibiotic resistance is the use of antibiotic adjuvants that hit bacterial non-essential targets. In this review, the author focuses on the discovery of antibiotic adjuvants and on new tools to study and reduce the prevalence of resistant bacterial infections.
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Affiliation(s)
- Giannamaria Annunziato
- Probes for Targets Group (P4T group), Department of food and Drug, University of Parma, 43124 Parma, Italy
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20
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Geisinger E, Huo W, Hernandez-Bird J, Isberg RR. Acinetobacter baumannii: Envelope Determinants That Control Drug Resistance, Virulence, and Surface Variability. Annu Rev Microbiol 2019; 73:481-506. [DOI: 10.1146/annurev-micro-020518-115714] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Acinetobacter baumannii has emerged as an important nosocomial pathogen, particularly for patients in intensive care units and with invasive indwelling devices. The most recent clinical isolates are resistant to several classes of clinically important antibiotics, greatly restricting the ability to effectively treat critically ill patients. The bacterial envelope is an important driver of A. baumannii disease, both at the level of battling against antibiotic therapy and at the level of protecting from host innate immune function. This review provides a comprehensive overview of key features of the envelope that interface with both the host and antimicrobial therapies. Carbohydrate structures that contribute to protecting from the host are detailed, and mutations that alter these structures, resulting in increased antimicrobial resistance, are explored. In addition, protein complexes involved in both intermicrobial and host-microbe interactions are described. Finally we discuss regulatory mechanisms that control the nature of the cell envelope and its impact on host innate immune function.
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Affiliation(s)
- Edward Geisinger
- Department of Biology, Northeastern University, Boston, Massachusetts 02115, USA
| | - Wenwen Huo
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Juan Hernandez-Bird
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Ralph R. Isberg
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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21
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Douafer H, Andrieu V, Phanstiel O, Brunel JM. Antibiotic Adjuvants: Make Antibiotics Great Again! J Med Chem 2019; 62:8665-8681. [PMID: 31063379 DOI: 10.1021/acs.jmedchem.8b01781] [Citation(s) in RCA: 160] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Multiple approaches have been developed to combat bacterial resistance. However, the combination of antibiotic resistance mechanisms by bacteria and the limited number of effective antibiotics available decreases the effective interventions for the treatment of current bacterial infections. This review covers the many ways that bacteria resist antibiotics including antibiotic target modification, the use of efflux pumps, and antibiotic inactivation. As a pertinent example, the use of beta lactamase inhibitors in combination with β-lactam containing antibiotics is discussed in detail. The solution to emerging antibiotic resistance may involve combination therapies of existing antibiotics and potentiating adjuvants, which re-empower the antibiotic agent to become efficacious against the resistant strain of interest. We report herein that a reasoned adjuvant design permits one to perform polypharmacy on bacteria by not only providing greater internal access to the codosed antibiotics but also by de-energizing the efflux pumps used by the bacteria to escape antibiotic action.
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Affiliation(s)
- Hana Douafer
- Aix Marseille University , INSERM, SSA, MCT , 13385 Marseille , France
| | - Véronique Andrieu
- Aix Marseille University , IRD, APHM, MEPHI, IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie , 13385 Marseille , France
| | - Otto Phanstiel
- 12722 Research Parkway, College of Medicine , University of Central Florida , Orlando , Florida 32826 , United States
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22
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Kaur S, Khatri M, Arya SK, Singh G. Stimulating effect of nanoparticles and salts on thermo and halo-tolerant cell-bonded laccase synthesis in Acinetobacter sp. UIETPU. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2019. [DOI: 10.1016/j.bcab.2019.101085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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23
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Bhamidimarri SP, Zahn M, Prajapati JD, Schleberger C, Söderholm S, Hoover J, West J, Kleinekathöfer U, Bumann D, Winterhalter M, van den Berg B. A Multidisciplinary Approach toward Identification of Antibiotic Scaffolds for Acinetobacter baumannii. Structure 2019; 27:268-280.e6. [DOI: 10.1016/j.str.2018.10.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Revised: 08/19/2018] [Accepted: 10/23/2018] [Indexed: 11/16/2022]
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24
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Golla VK, Sans-Serramitjana E, Pothula KR, Benier L, Bafna JA, Winterhalter M, Kleinekathöfer U. Fosfomycin Permeation through the Outer Membrane Porin OmpF. Biophys J 2019; 116:258-269. [PMID: 30616836 PMCID: PMC6350074 DOI: 10.1016/j.bpj.2018.12.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 11/21/2018] [Accepted: 12/03/2018] [Indexed: 01/14/2023] Open
Abstract
Fosfomycin is a frequently prescribed drug in the treatment of acute urinary tract infections. It enters the bacterial cytoplasm and inhibits the biosynthesis of peptidoglycans by targeting the MurA enzyme. Despite extensive pharmacological studies and clinical use, the permeability of fosfomycin across the bacterial outer membrane is largely unexplored. Here, we investigate the fosfomycin permeability across the outer membrane of Gram-negative bacteria by electrophysiology experiments as well as by all-atom molecular dynamics simulations including free-energy and applied-field techniques. Notably, in an electrophysiological zero-current assay as well as in the molecular simulations, we found that fosfomycin can rapidly permeate the abundant Escherichia coli porin OmpF. Furthermore, two triple mutants in the constriction region of the porin have been investigated. The permeation rates through these mutants are slightly lower than that of the wild type but fosfomycin can still permeate. Altogether, this work unravels molecular details of fosfomycin permeation through the outer membrane porin OmpF of E. coli and moreover provides hints for understanding the translocation of phosphonic acid antibiotics through other outer membrane pores.
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Affiliation(s)
- Vinaya Kumar Golla
- Department of Physics and Earth Sciences, Jacobs University Bremen, Bremen, Germany
| | | | | | - Lorraine Benier
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen, Germany
| | - Jayesh Arun Bafna
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen, Germany
| | - Mathias Winterhalter
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen, Germany
| | - Ulrich Kleinekathöfer
- Department of Physics and Earth Sciences, Jacobs University Bremen, Bremen, Germany.
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25
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In silico proteomic and phylogenetic analysis of the outer membrane protein repertoire of gastric Helicobacter species. Sci Rep 2018; 8:15453. [PMID: 30337679 PMCID: PMC6194013 DOI: 10.1038/s41598-018-32476-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 09/03/2018] [Indexed: 12/16/2022] Open
Abstract
Helicobacter (H.) pylori is an important risk factor for gastric malignancies worldwide. Its outer membrane proteome takes an important role in colonization of the human gastric mucosa. However, in zoonotic non-H. pylori helicobacters (NHPHs) also associated with human gastric disease, the composition of the outer membrane (OM) proteome and its relative contribution to disease remain largely unknown. By means of a comprehensive survey of the diversity and distribution of predicted outer membrane proteins (OMPs) identified in all known gastric Helicobacter species with fully annotated genome sequences, we found genus- and species-specific families known or thought to be implicated in virulence. Hop adhesins, part of the Helicobacter-specific family 13 (Hop, Hor and Hom) were restricted to the gastric species H. pylori, H. cetorum and H. acinonychis. Hof proteins (family 33) were putative adhesins with predicted Occ- or MOMP-family like 18-stranded β-barrels. They were found to be widespread amongst all gastric Helicobacter species only sporadically detected in enterohepatic Helicobacter species. These latter are other members within the genus Helicobacter, although ecologically and genetically distinct. LpxR, a lipopolysaccharide remodeling factor, was also detected in all gastric Helicobacter species but lacking as well from the enterohepatic species H. cinaedi, H. equorum and H. hepaticus. In conclusion, our systemic survey of Helicobacter OMPs points to species and infection-site specific members that are interesting candidates for future virulence and colonization studies.
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26
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Samanta S, Bodrenko I, Acosta-Gutiérrez S, D’Agostino T, Pathania M, Ghai I, Schleberger C, Bumann D, Wagner R, Winterhalter M, van den Berg B, Ceccarelli M. Getting Drugs through Small Pores: Exploiting the Porins Pathway in Pseudomonas aeruginosa. ACS Infect Dis 2018; 4:1519-1528. [PMID: 30039960 DOI: 10.1021/acsinfecdis.8b00149] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Understanding molecular properties of outer membrane channels of Gram-negative bacteria is of fundamental significance as they are the entry point of polar antibiotics into bacteria. Outer membrane proteomics revealed OccK8 (OprE) to be among the five most expressed substrate specific channels of the clinically important Pseudomonas aeruginosa. The high-resolution X-ray structure and electrophysiology highlighted a very narrow pore. However, experimental in vitro methods showed the transport of natural amino acids and antibiotics, among them ceftazidime. We used molecular dynamics simulations to reveal the importance of the physicochemical properties of ceftazidime in modulating the translocation through OccK8, proposing a structure-function relationship. As in general porins, the internal electric field favors the translocation of polar molecules by gainful energy compensation in the central constriction region. Importantly, the comparatively narrow OccK8 pore can undergo a substrate-induced expansion to accommodate relatively large-sized substrates.
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Affiliation(s)
- Susruta Samanta
- Department of Physics, University of Cagliari, SP Monserrato-Sestu Km 0.8, Monserrato, 09042, Italy
- Department of Chemistry, Manipal University Jaipur, VPO Dehmi Kalan, Jaipur, Rajasthan 303007, India
| | - Igor Bodrenko
- Department of Physics, University of Cagliari, SP Monserrato-Sestu Km 0.8, Monserrato, 09042, Italy
| | - Silvia Acosta-Gutiérrez
- Department of Physics, University of Cagliari, SP Monserrato-Sestu Km 0.8, Monserrato, 09042, Italy
| | - Tommaso D’Agostino
- Department of Physics, University of Cagliari, SP Monserrato-Sestu Km 0.8, Monserrato, 09042, Italy
| | - Monisha Pathania
- Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Ishan Ghai
- Department of Life Sciences and Chemistry, Jacobs University Bremen, 28719 Bremen, Germany
| | - Christian Schleberger
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| | - Dirk Bumann
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| | - Richard Wagner
- Department of Life Sciences and Chemistry, Jacobs University Bremen, 28719 Bremen, Germany
| | - Mathias Winterhalter
- Department of Life Sciences and Chemistry, Jacobs University Bremen, 28719 Bremen, Germany
| | - Bert van den Berg
- Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Matteo Ceccarelli
- Department of Physics, University of Cagliari, SP Monserrato-Sestu Km 0.8, Monserrato, 09042, Italy
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27
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Abellón-Ruiz J, Zahn M, Baslé A, van den Berg B. Crystal structure of theAcinetobacter baumanniiouter membrane protein Omp33. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2018; 74:852-860. [DOI: 10.1107/s205979831800904x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 06/20/2018] [Indexed: 12/31/2022]
Abstract
Acinetobacter baumanniiis becoming a major threat to human health due to its multidrug resistance. This is owing in a large part to the low permeability of its outer membrane (OM), which prevents high internal antibiotic concentrations and makes antibiotic-resistance mechanisms more effective. To exploit OM channels as potential delivery vehicles for future antibiotics, structural information is required. One abundant OM protein inA. baumanniiis Omp33. This protein has been reported to be important for thein vivofitness and virulence ofA. baumannii, but its structure is not known. Here, the X-ray crystal structure of Omp33 is reported at a resolution of 2.1 Å. Omp33 has a 14-β-stranded barrel without stable extracellular loop constrictions. Instead, an extended and unusual periplasmic turn connecting β-strands 2 and 3 is present, which folds into the pore lumen and completely blocks the aqueous channel. The Omp33 structure helps in understanding howA. baumanniiOM proteins contribute to the low permeability of the cell envelope of this bacterium and suggests that Omp33 might function as a gated channel.
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28
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Rodrigues-Costa F, Cayô R, Matos AP, Girardello R, Martins WMBS, Carrara-Marroni FE, Gales AC. Temporal evolution of Acinetobacter baumannii ST107 clone: conversion of bla OXA-143 into bla OXA-231 coupled with mobilization of ISAba1 upstream occAB1. Res Microbiol 2018; 170:53-59. [PMID: 30003961 DOI: 10.1016/j.resmic.2018.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 06/30/2018] [Accepted: 07/03/2018] [Indexed: 11/19/2022]
Abstract
Nine carbapenem-resistant Acinetobacter baumannii isolates carrying blaOXA-231 and an ISAba1 upstream occAB1 were evaluated. They were clonally related and belonged to ST107. An OXA-143-producing A. baumannii ST107 strain (Ac-148) that did not possess ISAba1 upstream occAB1 was included in the analysis. Reduction in the expression of occAB1 and a 4-fold increase of carbapenem MICs were observed for all isolates, except for the Ac-148 strain, probably due to the presence of ISAba1 upstream occAB1 but in the same transcriptional orientation. We reported an A. baumannii ST107 clone carrying blaOXA-143 that acquired a mutation resulting into blaOXA-231 and mobilized ISAba1 upstream occAB1.
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Affiliation(s)
- Fernanda Rodrigues-Costa
- Universidade Federal de São Paulo - UNIFESP, Laboratório Alerta, Disciplina de Infectologia, Departamento de Medicina, Escola Paulista de Medicina - EPM, São Paulo - SP, Brazil
| | - Rodrigo Cayô
- Universidade Federal de São Paulo - UNIFESP, Laboratório Alerta, Disciplina de Infectologia, Departamento de Medicina, Escola Paulista de Medicina - EPM, São Paulo - SP, Brazil.
| | - Adriana Pereira Matos
- Universidade Federal de São Paulo - UNIFESP, Laboratório Alerta, Disciplina de Infectologia, Departamento de Medicina, Escola Paulista de Medicina - EPM, São Paulo - SP, Brazil
| | - Raquel Girardello
- Universidade Federal de São Paulo - UNIFESP, Laboratório Alerta, Disciplina de Infectologia, Departamento de Medicina, Escola Paulista de Medicina - EPM, São Paulo - SP, Brazil
| | - Willames M B S Martins
- Universidade Federal de São Paulo - UNIFESP, Laboratório Alerta, Disciplina de Infectologia, Departamento de Medicina, Escola Paulista de Medicina - EPM, São Paulo - SP, Brazil
| | - Floristher Elaine Carrara-Marroni
- Laboratório de Microbiologia Clínica, Hospital Universitário de Londrina, Departamento de Patologia Análises Clínicas e Toxicológicas, Universidade Estadual de Londrina - UEL, Londrina - PR, Brazil
| | - Ana Cristina Gales
- Universidade Federal de São Paulo - UNIFESP, Laboratório Alerta, Disciplina de Infectologia, Departamento de Medicina, Escola Paulista de Medicina - EPM, São Paulo - SP, Brazil
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29
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Tight Turns of Outer Membrane Proteins: An Analysis of Sequence, Structure, and Hydrogen Bonding. J Mol Biol 2018; 430:3251-3265. [PMID: 29944853 DOI: 10.1016/j.jmb.2018.06.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 05/29/2018] [Accepted: 06/04/2018] [Indexed: 11/21/2022]
Abstract
As a structural class, tight turns can control molecular recognition, enzymatic activity, and nucleation of folding. They have been extensively characterized in soluble proteins but have not been characterized in outer membrane proteins (OMPs), where they also support critical functions. We clustered the 4 to 6 residue tight turns of 110 OMPs to characterize the phi/psi angles, sequence, and hydrogen bonding of these structures. We find significant differences between reports of soluble protein tight turns and OMP tight turns. Since OMP strands are less twisted than soluble strands, they favor different turn structures types. Moreover, the membrane localization of OMPs yields different sequence hallmarks for their tight turns relative to soluble protein turns. We also characterize the differences in phi/psi angles, sequence, and hydrogen bonding between OMP extracellular loops and OMP periplasmic turns. As previously noted, the extracellular loops tend to be much longer than the periplasmic turns. We find that this difference in length is due to the broader distribution of lengths of the extracellular loops not a large difference in the median length. Extracellular loops also tend to have more charged residues as predicted by the charge-out rule. Finally, in all OMP tight turns, hydrogen bonding between the side chain and backbone 2 to 4 residues away from that side chain plays an important role. These bonds preferentially use an Asp, Asn, Ser, or Thr residue in a beta or pro phi/psi conformation. We anticipate that this study will be applicable to future design and structure prediction of OMPs.
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Abstract
Our limited understanding of the molecular basis for compound entry into and efflux out of Gram-negative bacteria is now recognized as a key bottleneck for the rational discovery of novel antibacterial compounds. Traditional, large-scale biochemical or target-agnostic phenotypic antibacterial screening efforts have, as a result, not been very fruitful. A main driver of this knowledge gap has been the historical lack of predictive cellular assays, tools, and models that provide structure-activity relationships to inform optimization of compound accumulation. A variety of recent approaches has recently been described to address this conundrum. This Perspective explores these approaches and considers ways in which their integration could successfully redirect antibacterial drug discovery efforts.
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Affiliation(s)
- Rubén Tommasi
- Entasis Therapeutics, Inc., 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Ramkumar Iyer
- Entasis Therapeutics, Inc., 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Alita A. Miller
- Entasis Therapeutics, Inc., 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
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Abstract
Collective antibiotic drug resistance is a global threat, especially with respect to Gram-negative bacteria. The low permeability of the bacterial outer cell wall has been identified as a challenging barrier that prevents a sufficient antibiotic effect to be attained at low doses of the antibiotic. The Gram-negative bacterial cell envelope comprises an outer membrane that delimits the periplasm from the exterior milieu. The crucial mechanisms of antibiotic entry via outer membrane includes general diffusion porins (Omps) responsible for hydrophilic antibiotics and lipid-mediated pathway for hydrophobic antibiotics. The protein and lipid arrangements of the outer membrane have had a strong impact on the understanding of bacteria and their resistance to many types of antibiotics. Thus, one of the current challenges is effective interpretation at the molecular basis of the outer membrane permeability. This review attempts to develop a state of knowledge pertinent to Omps and their effective role in solute influx. Moreover, it aims toward further understanding and exploration of prospects to improve our knowledge of physicochemical limitations that direct the translocation of antibiotics via bacterial outer membrane.
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Affiliation(s)
- Ishan Ghai
- School of Engineering and Life Sciences, Jacobs University, Bremen, Germany.,Consultation Division, RSGBIOGEN, New Delhi, India
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Benkerrou D, Ceccarelli M. Free energy calculations and molecular properties of substrate translocation through OccAB porins. Phys Chem Chem Phys 2018. [DOI: 10.1039/c7cp08299a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We investigated with molecular modeling the translocation of simple substrates through four similar specific bacterial porins from the Acinetobacter baumannii pathogen providing structure–function analysis at the molecular level.
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Abstract
One of the main fundamental mechanisms of antibiotic resistance in Gram-negative bacteria comprises an effective change in the membrane permeability to antibiotics. The Gram-negative bacterial complex cell envelope comprises an outer membrane that delimits the periplasm from the exterior environment. The outer membrane contains numerous protein channels, termed as porins or nanopores, which are mainly involved in the influx of hydrophilic compounds, including antibiotics. Bacterial adaptation to reduce influx through these outer membrane proteins (Omps) is one of the crucial mechanisms behind antibiotic resistance. Thus to interpret the molecular basis of the outer membrane permeability is the current challenge. This review attempts to develop a state of knowledge pertinent to Omps and their effective role in antibiotic influx. Further, it aims to study the bacterial response to antibiotic membrane permeability and hopefully provoke a discussion toward understanding and further exploration of prospects to improve our knowledge on physicochemical parameters that direct the translocation of antibiotics through the bacterial membrane protein channels.
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Affiliation(s)
- Ishan Ghai
- School of Engineering and Life Sciences, Jacobs University, Bremen
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The Acinetobacter Outer Membrane Contains Multiple Specific Channels for Carbapenem β-Lactams as Revealed by Kinetic Characterization Analyses of Imipenem Permeation into Acinetobacter baylyi Cells. Antimicrob Agents Chemother 2017; 61:AAC.01737-16. [PMID: 28069648 DOI: 10.1128/aac.01737-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 12/28/2016] [Indexed: 12/31/2022] Open
Abstract
The number and type of outer membrane (OM) channels responsible for carbapenem uptake in Acinetobacter are still not well defined. Here, we addressed these questions by using Acinetobacter baylyi as a model species and a combination of methodologies aimed to characterize OM channels in their original membrane environment. Kinetic and competition analyses of imipenem (IPM) uptake by A. baylyi whole cells allowed us to identify different carbapenem-specific OM uptake sites. Comparative analyses of IPM uptake by A. baylyi wild-type (WT) cells and ΔcarO mutants lacking CarO indicated that this OM protein provided a carbapenem uptake site displaying saturable kinetics and common binding sites for basic amino acids compatible with a specific channel. The kinetic analysis uncovered another carbapenem-specific channel displaying a somewhat lower affinity for IPM than that of CarO and, in addition, common binding sites for basic amino acids as determined by competition studies. The use of A. baylyi gene deletion mutants lacking OM proteins proposed to function in carbapenem uptake in Acinetobacter baumannii indicated that CarO and OprD/OccAB1 mutants displayed low but consistent reductions in susceptibility to different carbapenems, including IPM, meropenem, and ertapenem. These two mutants also showed impaired growth on l-Arg but not on other carbon sources, further supporting a role of CarO and OprD/OccAB1 in basic amino acid and carbapenem uptake. A multiple-carbapenem-channel scenario may provide clues to our understanding of the contribution of OM channel loss or mutation to the carbapenem-resistant phenotype evolved by pathogenic members of the Acinetobacter genus.
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An ompR-envZ Two-Component System Ortholog Regulates Phase Variation, Osmotic Tolerance, Motility, and Virulence in Acinetobacter baumannii Strain AB5075. J Bacteriol 2017; 199:JB.00705-16. [PMID: 27872182 DOI: 10.1128/jb.00705-16] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 11/14/2016] [Indexed: 11/20/2022] Open
Abstract
Recently, a novel phase-variable colony opacity phenotype was discovered in Acinetobacter baumannii strain AB5075, where colonies interconvert between opaque and translucent variants. Opaque colonies become mottled or sectored after 24 h of growth due to translucent variants arising within the colony. This easily distinguishable opaque-colony phenotype was used to screen for random transposon insertions that increased the frequency of sectoring at a time point when wild-type colonies were uniformly opaque. A colony was identified that contained multiple papillae of translucent variants, and the insertion in this mutant mapped to an ortholog of the two-component system response regulator ompR Subsequent investigation of in-frame deletions of ompR and the sensor kinase envZ (located adjacent to ompR) showed that the switching frequency from opaque to translucent was increased 401- and 281-fold, respectively. The ompR mutant also exhibited sensitivity to sodium chloride in growth medium, whereas the envZ mutation did not elicit sensitivity to sodium chloride. Mutation of either gene reduced motility in A. baumannii strain AB5075, but a mutation in both ompR and envZ produced a more profound effect. The ompR and envZ genes were cotranscribed but were not subject to autoregulation by OmpR. Both ompR and envZ mutant opaque variants were attenuated in virulence in the Galleria mellonella infection model, whereas mutation of ompR had no effect on the virulence of the translucent variant. IMPORTANCEAcinetobacter baumannii is a well-known antibiotic-resistant pathogen; many clinical isolates can only be treated by a very small number of antibiotics (including colistin), while some exhibit panresistance. The current antimicrobial arsenal is nearing futility in the treatment of Acinetobacter infections, and new avenues of treatment are profoundly needed. Since phase variation controls the transition between opaque (virulent) and translucent (avirulent) states in A. baumannii, this may represent an "Achilles' heel" that can be targeted via the development of small molecules that lock cells in the translucent state and allow the host immune system to clear the infection. A better understanding of how phase variation is regulated may allow for the development of methods to target this process. The ompR-envZ two-component system ortholog negatively regulates phase variation in A. baumannii, and perturbation of this system leads to the attenuation of virulence in an invertebrate infection model.
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Brown DG. Drug discovery strategies to outer membrane targets in Gram-negative pathogens. Bioorg Med Chem 2016; 24:6320-6331. [PMID: 27178386 DOI: 10.1016/j.bmc.2016.05.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 04/22/2016] [Accepted: 05/03/2016] [Indexed: 11/26/2022]
Abstract
This review will cover selected recent examples of drug discovery strategies which target the outer membrane (OM) of Gram-negative bacteria either by disruption of outer membrane function or by inhibition of essential gene products necessary for outer membrane assembly. Significant advances in pathway elucidation, structural biology and molecular inhibitor designs have created new opportunities for drug discovery within this target-class space.
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Affiliation(s)
- Dean G Brown
- AstraZeneca Neurosciences, Innovative Medicines and Early Development Unit, 141 Portland St., 10th Floor, Cambridge, MA 02139, USA.
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Mousa JJ, Bruner SD. Structural and mechanistic diversity of multidrug transporters. Nat Prod Rep 2016; 33:1255-1267. [DOI: 10.1039/c6np00006a] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The review article surveys recent structural and mechanistic advances in the field of multi-drug and natural product transporters.
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