1
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Yeo JH, Begam N, Leow WT, Goh JX, Zhong Y, Cai Y, Kwa ALH. Ironing out Persisters? Revisiting the Iron Chelation Strategy to Target Planktonic Bacterial Persisters Harboured in Carbapenem-Resistant Escherichia coli. Microorganisms 2024; 12:972. [PMID: 38792801 PMCID: PMC11123761 DOI: 10.3390/microorganisms12050972] [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: 03/15/2024] [Revised: 05/02/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024] Open
Abstract
Antibiotic resistance is a global health crisis. Notably, carbapenem-resistant Enterobacterales (CRE) pose a significant clinical challenge due to the limited effective treatment options. This problem is exacerbated by persisters that develop upon antibiotic exposure. Bacteria persisters can tolerate high antibiotic doses and can cause recalcitrant infections, potentially developing further antibiotic resistance. Iron is a critical micronutrient for survival. We aimed to evaluate the utility of iron chelators, alone and in combination with antibiotics, in managing persisters. We hypothesized that iron chelators eradicate CRE persisters in vitro, when administered in combination with antibiotics. Our screening revealed three clinical isolates with bacteria persisters that resuscitated upon antibiotic removal. These isolates were treated with both meropenem and an iron chelator (deferoxamine mesylate, deferiprone or dexrazoxane) over 24 h. Against our hypothesis, bacteria persisters survived and resuscitated upon withdrawing both the antibiotic and iron chelator. Pursuing our aim, we next hypothesized that iron chelation is feasible as a post-antibiotic treatment in managing and suppressing persisters' resuscitation. We exposed bacteria persisters to an iron chelator without antibiotics. Flow cytometric assessments revealed that iron chelators are inconsistent in suppressing persister resuscitation. Collectively, these results suggest that the iron chelation strategy may not be useful as an antibiotic adjunct to target planktonic bacteria persisters.
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Affiliation(s)
- Jia Hao Yeo
- Department of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore; (J.H.Y.)
- SingHealth-Duke-NUS Academic Clinical Programme (Pathology), Singapore 169857, Singapore
| | - Nasren Begam
- Department of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore; (J.H.Y.)
| | - Wan Ting Leow
- Department of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore; (J.H.Y.)
| | - Jia Xuan Goh
- Department of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore; (J.H.Y.)
| | - Yang Zhong
- Department of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore; (J.H.Y.)
- Department of Clinical Translational Research, Singapore General Hospital, Singapore 169856, Singapore
| | - Yiying Cai
- Department of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore; (J.H.Y.)
| | - Andrea Lay-Hoon Kwa
- Department of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore; (J.H.Y.)
- SingHealth-Duke-NUS Academic Clinical Programme (Medicine), Singapore 169857, Singapore
- Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore 169857, Singapore
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2
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Rajapaksha DC, Edirisinghe SL, Nikapitiya C, Whang I, De Zoysa M. The Antimicrobial Peptide Octopromycin Suppresses Biofilm Formation and Quorum Sensing in Acinetobacter baumannii. Antibiotics (Basel) 2023; 12:antibiotics12030623. [PMID: 36978490 PMCID: PMC10044867 DOI: 10.3390/antibiotics12030623] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 03/03/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
Acinetobacter baumannii is an opportunistic bacterial pathogen that causes severe infections in immunocompromised individuals. A. baumannii forms biofilm and produces extracellular matrix, which supports bacteria to survive under harsh conditions and be resistant to antibacterial treatments. In the present study, we investigated the biofilm and quorum-sensing inhibitory effects of antimicrobial peptide, octopromycin in A. baumannii. Field emission-scanning electron microscopy results clearly showed significantly reduced biofilm mass and caused a collapse in biofilm architecture at the minimum inhibitory concentration (50 µg/mL) and minimum bactericidal concentration (200 µg/mL) of octopromycin. Antibiotic-resistant persister cells of A. baumannii were successfully killed by octopromycin treatment, and it inhibited violacein production in Chromobacterium violaceum in a concentration-dependent manner. Octopromycin also inhibited alginate production, surface movements (swarming and swimming), and twitching motility of A. baumannnii, confirming its anti-quorum-sensing activity. Multiple metabolic pathways, two-component regulation systems, quorum-sensing, and antibiotic synthesis-related pathways in A. baumannii biofilms were strongly affected by octopromycin treatment. The collective findings indicate that the antibacterial peptide octopromycin may control A. baumannii biofilms through multi-target interactions. Octopromycin could be a desirable therapeutic option for the prevention and control of A. baumannii infections.
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Affiliation(s)
- Dinusha Chathurangi Rajapaksha
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Shan Lakmal Edirisinghe
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Chamilani Nikapitiya
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Ilson Whang
- National Marine Biodiversity Institute of Korea (MABIK), 75, Jangsan-ro 101 beon-gil, Janghang-eup, Seochun-gun 33662, Chungchungnam-do, Republic of Korea
| | - Mahanama De Zoysa
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Daejeon 34134, Republic of Korea
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3
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Bulman ZP, Wicha SG, Nielsen EI, Lenhard JR, Nation RL, Theuretzbacher U, Derendorf H, Tängdén T, Zeitlinger M, Landersdorfer CB, Bulitta JB, Friberg LE, Li J, Tsuji BT. Research priorities towards precision antibiotic therapy to improve patient care. THE LANCET. MICROBE 2022; 3:e795-e802. [PMID: 35777386 DOI: 10.1016/s2666-5247(22)00121-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 04/04/2022] [Accepted: 04/28/2022] [Indexed: 12/24/2022]
Abstract
Antibiotic resistance presents an incessant threat to our drug armamentarium that necessitates novel approaches to therapy. Over the past several decades, investigation of pharmacokinetic and pharmacodynamic (PKPD) principles has substantially improved our understanding of the relationships between the antibiotic, pathogen, and infected patient. However, crucial gaps in our understanding of the pharmacology of antibacterials and their optimal use in the care of patients continue to exist; simply attaining antibiotic exposures that are considered adequate based on traditional targets can still result in treatment being unsuccessful and resistance proliferation for some infections. It is this salient paradox that points to key future directions for research in antibiotic therapeutics. This Personal View discusses six priority areas for antibiotic pharmacology research: (1) antibiotic-pathogen interactions, (2) antibiotic targets for combination therapy, (3) mechanistic models that describe the time-course of treatment response, (4) understanding and modelling of host response to infection, (5) personalised medicine through therapeutic drug management, and (6) application of these principles to support development of novel therapies. Innovative approaches that enhance our understanding of antibiotic pharmacology and facilitate more accurate predictions of treatment success, coupled with traditional pharmacology research, can be applied at the population level and to individual patients to improve outcomes.
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Affiliation(s)
- Zackery P Bulman
- Department of Pharmacy Practice, University of Illinois Chicago, Chicago, IL, USA.
| | - Sebastian G Wicha
- Department of Clinical Pharmacy, Institute of Pharmacy, University of Hamburg, Hamburg, Germany
| | | | - Justin R Lenhard
- Department of Clinical and Administrative Sciences, California Northstate University College of Pharmacy, Elk Grove, CA, USA
| | - Roger L Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | | | - Hartmut Derendorf
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, FL, USA
| | - Thomas Tängdén
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Markus Zeitlinger
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Cornelia B Landersdorfer
- Centre for Medicine Use and Safety, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Jürgen B Bulitta
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, FL, USA
| | - Lena E Friberg
- Department of Pharmacy, Uppsala University, Uppsala, Sweden
| | - Jian Li
- Monash Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Melbourne, VIC, Australia
| | - Brian T Tsuji
- Department of Pharmacy Practice, University at Buffalo, Buffalo, NY, USA
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4
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Jiang X, Han M, Tran K, Patil NA, Ma W, Roberts KD, Xiao M, Sommer B, Schreiber F, Wang L, Velkov T, Li J. An Intelligent Strategy with All-Atom Molecular Dynamics Simulations for the Design of Lipopeptides against Multidrug-Resistant Pseudomonas aeruginosa. J Med Chem 2022; 65:10001-10013. [PMID: 35786900 DOI: 10.1021/acs.jmedchem.2c00657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Multidrug-resistant Gram-negative bacteria seriously threaten modern medicine due to the lack of efficacious therapeutic options. Their outer membrane (OM) is an essential protective fortress to exclude many antibiotics. Unfortunately, current structural biology methods are not able to resolve the membrane structure and it is difficult to examine the specific interaction between the OM and small molecules. These limitations hinder mechanistic understanding of antibiotic penetration through the OM and antibiotic discovery. Here, we developed biologically relevant OM models by quantitatively determining membrane lipidomics of Pseudomonas aeruginosa and elucidated how lipopolysaccharide modifications and OM vesicles mediated resistance to polymyxins. Supported by chemical biology and pharmacological assays, our multiscale molecular dynamics simulations provide an intelligent platform to quantify the membrane-penetrating thermodynamics of peptides and predict their antimicrobial activity. Through experimental validations with our in-house polymyxin analogue library, our computational strategy may have significant potential in accelerating the discovery of lipopeptides against bacterial "superbugs".
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Affiliation(s)
- Xukai Jiang
- National Glycoengineering Research Center, Shandong University, Qingdao 266237, China
| | - Meiling Han
- Biomedicine Discovery Institute, Infection Program and Department of Microbiology, Monash University, Melbourne 3800, Australia
| | - Kevin Tran
- Biomedicine Discovery Institute, Infection Program and Department of Microbiology, Monash University, Melbourne 3800, Australia
| | - Nitin A Patil
- Biomedicine Discovery Institute, Infection Program and Department of Microbiology, Monash University, Melbourne 3800, Australia
| | - Wendong Ma
- Biomedicine Discovery Institute, Infection Program and Department of Microbiology, Monash University, Melbourne 3800, Australia
| | - Kade D Roberts
- Biomedicine Discovery Institute, Infection Program and Department of Microbiology, Monash University, Melbourne 3800, Australia
| | - Min Xiao
- National Glycoengineering Research Center, Shandong University, Qingdao 266237, China
| | - Bjorn Sommer
- Department of Computer and Information Science, University of Konstanz, Konstanz 78457, Germany
| | - Falk Schreiber
- Department of Computer and Information Science, University of Konstanz, Konstanz 78457, Germany
| | - Lushan Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Tony Velkov
- Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne 3010, Australia
| | - Jian Li
- Biomedicine Discovery Institute, Infection Program and Department of Microbiology, Monash University, Melbourne 3800, Australia
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5
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Hu G, Liu W, Wang M. Polymyxin B, Cefoperazone Sodium-Sulbactam Sodium, and Tigecycline against Multidrug-Resistant Acinetobacter baumannii Pneumonia. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2022; 2022:1968020. [PMID: 35685727 PMCID: PMC9173994 DOI: 10.1155/2022/1968020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 05/09/2022] [Accepted: 05/23/2022] [Indexed: 11/17/2022]
Abstract
Purpose The purpose of this study is to investigate the significance of polymyxin B in combination with cefoperazone sodium-sulbactam sodium (CSSS) and tigecycline for the treatment of multidrug-resistant Acinetobacter baumannii- (MDRAB-) induced pneumonia on the levels of white blood cell (WBC) count, serum C-reactive protein (CRP), and procalcitonin (PCT). Methods Fifty-six patients with MDRAB pneumonia admitted to the Fifth People's Hospital of Wuhu from February 2019 to December 2021 were randomized into the observation group (n = 28) and the experimental group (n = 28) by the random table method. The observation group received intravenous infusion of CSSS and tigecycline. The experimental group received intravenous infusion of polymyxin B sulfate plus CSSS and tigecycline. All patients were treated for 14 days. Results There was no significant difference in the overall response rate between the two groups; the bacterial clearance of the experimental group was significantly higher than that of the observation group; there was no significant difference in the WBC, CRP, and PCT levels between the two groups prior to the treatment; but after treatment, while the WBC, CRP, and PCT levels of the two groups decreased, the WBC count, CRP, and PCT levels of the experimental group were significantly lower than those of the observation group; no significant difference was found in adverse reactions. Conclusion Polymyxin B-CSSS-tigecycline has good clinical efficacy in the treatment of MDRAB pneumonia. It not only improves the patients' bacterial clearance rate and effectively reduces the levels of WBC count, serum CRP, and PCT, but also raises no risk of adverse reactions. Therefore, it is worthy of clinical promotion.
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Affiliation(s)
- Guangxue Hu
- Laboratory Department, The Fifth People's Hospital of Wuhu, Wuhu, Anhui Province, China
| | - Wanzong Liu
- Laboratory Department, The Fifth People's Hospital of Wuhu, Wuhu, Anhui Province, China
| | - Mali Wang
- Laboratory Department, The Fifth People's Hospital of Wuhu, Wuhu, Anhui Province, China
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6
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Tobramycin Stress Induced Differential Gene Expression in Acinetobacter baumannii. Curr Microbiol 2022; 79:88. [PMID: 35129693 DOI: 10.1007/s00284-022-02788-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 01/24/2022] [Indexed: 11/03/2022]
Abstract
Acinetobacter baumannii is a multidrug-resistant bacteria responsible for nosocomial infections with significant fatality rates globally. Therapeutic failure and relapse of infection has been associated with persister cells formation which can also lead to resistance in A. baumannii. In the present study, we observed that A. baumannii ATCC 17978 in exponential phase survived lethal concentrations of amikacin, rifampicin and ciprofloxacin by generating persister cells but was unable to survive tobramycin treatment. The transcriptome of A. baumannii ATCC 17978 was analyzed following exposure to a high concentration of tobramycin (10 × MIC) for a short period of time to study the possible mechanisms responsible for lethality. Tobramycin reduced the expression of genes involved in energy production (nuoH, nuoN, nuoM, cydA, sucC), oxidative stress protection (tauD, cysD), and nutrition uptake (ompW) significantly. In addition, hemerythrin (non-heme di-iron oxygen-binding protein) was found to be the most downregulated gene in response to tobramycin which needs to be further studied for its role in susceptibility to antibiotics. Tobramycin upregulated the expression of genes that are mainly involved in stress response (leucine catabolism, DNA repair and HicAB toxin-antitoxin system). The differentially expressed genes highlighted in the study provided insight into the probable molecular mechanism of tobramycin-induced cell death and revealed some novel targets that can be explored further for their potential to control A. baumannii.
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7
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Kashyap S, Sharma P, Capalash N. Potential genes associated with survival of Acinetobacter baumannii under ciprofloxacin stress. Microbes Infect 2021; 23:104844. [PMID: 34098109 DOI: 10.1016/j.micinf.2021.104844] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/14/2021] [Accepted: 05/22/2021] [Indexed: 11/25/2022]
Abstract
Acinetobacter baumannii is an opportunistic pathogen that has acquired resistance to all available drugs. The rise in multi-drug resistance in A. baumannii has been exacerbated by its ability to tolerate antibiotics due to the persister cells, which are phenotypic variants of normal cells that can survive various stress conditions, resulting in chronicity of infection. In the present study we observed that A. baumannii formed persister cells against lethal concentration of ciprofloxacin in exponential phase. The transcriptome of A. baumannii was analyzed after exposure to high concentration of ciprofloxacin (50X MIC) to determine the possible mechanisms of survival. Transcriptome analysis showed differential expression of 146 genes, of which 101 were up-regulated and 45 were down-regulated under ciprofloxacin stress. Differentially expressed genes that might be important for persistence against ciprofloxacin were involved in DNA repair, phenylacetic acid degradation, leucine catabolism, HicAB toxin-antitoxin system and ROS response (iron-sulfur clusters, hemerythrin-like metal binding and Kdp). recA, umuD and ddrR genes involved in SOS response were also up-regulated. Knockout of umuD showed significant decrease in persister cells formation while they were completely eradicated in recA mutant strain. The differentially expressed genes highlighted in the study merit further investigation as therapeutic targets for effective control of A. baumannii infections.
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Affiliation(s)
- Shruti Kashyap
- Department of Biotechnology, Panjab University, BMS Block-I, Sector-25, Chandigarh, India, 160014
| | - Prince Sharma
- Department of Microbiology, Panjab University, BMS Block-I, Sector-25, Chandigarh, India, 160014
| | - Neena Capalash
- Department of Biotechnology, Panjab University, BMS Block-I, Sector-25, Chandigarh, India, 160014.
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8
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Wickremasinghe H, Yu HH, Azad MAK, Zhao J, Bergen PJ, Velkov T, Zhou QT, Zhu Y, Li J. Clinically Relevant Concentrations of Polymyxin B and Meropenem Synergistically Kill Multidrug-Resistant Pseudomonas aeruginosa and Minimize Biofilm Formation. Antibiotics (Basel) 2021; 10:405. [PMID: 33918040 PMCID: PMC8069709 DOI: 10.3390/antibiotics10040405] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 03/31/2021] [Accepted: 04/02/2021] [Indexed: 12/13/2022] Open
Abstract
The emergence of antibiotic resistance has severely impaired the treatment of chronic respiratory infections caused by multidrug-resistant (MDR) Pseudomonas aeruginosa. Since the reintroduction of polymyxins as a last-line therapy against MDR Gram-negative bacteria, resistance to its monotherapy and recurrent infections continue to be reported and synergistic antibiotic combinations have been investigated. In this study, comprehensive in vitro microbiological evaluations including synergy panel screening, population analysis profiling, time-kill kinetics, anti-biofilm formation and membrane damage analysis studies were conducted to evaluate the combination of polymyxin B and meropenem against biofilm-producing, polymyxin-resistant MDR P. aeruginosa. Two phylogenetically unrelated MDR P. aeruginosa strains, FADDI-PA060 (MIC of polymyxin B [MICpolymyxin B], 64 mg/L; MICmeropenem, 64 mg/L) and FADDI-PA107 (MICpolymyxin B, 32 mg/L; MICmeropenem, 4 mg/L) were investigated. Genome sequencing identified 57 (FADDI-PA060) and 50 (FADDI-PA107) genes predicted to confer resistance to a variety of antimicrobials, as well as multiple virulence factors in each strain. The presence of resistance genes to a particular antibiotic class generally aligned with MIC results. For both strains, all monotherapies of polymyxin B failed with substantial regrowth and biofilm formation. The combination of polymyxin B (16 mg/L)/meropenem (16 mg/L) was most effective, enhancing initial bacterial killing of FADDI-PA060 by ~3 log10 CFU/mL, followed by a prolonged inhibition of regrowth for up to 24 h with a significant reduction in biofilm formation (* p < 0.05). Membrane integrity studies revealed a substantial increase in membrane depolarization and membrane permeability in the surviving cells. Against FADDI-PA107, planktonic and biofilm bacteria were completely eradicated. In summary, the combination of polymyxin B and meropenem demonstrated synergistic bacterial killing while reinstating the efficacy of two previously ineffective antibiotics against difficult-to-treat polymyxin-resistant MDR P. aeruginosa.
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Affiliation(s)
- Hasini Wickremasinghe
- Infection and Immunity Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (H.H.Y.); (M.A.K.A.); (J.Z.); (P.J.B.); (Y.Z.); (J.L.)
| | - Heidi H. Yu
- Infection and Immunity Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (H.H.Y.); (M.A.K.A.); (J.Z.); (P.J.B.); (Y.Z.); (J.L.)
| | - Mohammad A. K. Azad
- Infection and Immunity Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (H.H.Y.); (M.A.K.A.); (J.Z.); (P.J.B.); (Y.Z.); (J.L.)
| | - Jinxin Zhao
- Infection and Immunity Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (H.H.Y.); (M.A.K.A.); (J.Z.); (P.J.B.); (Y.Z.); (J.L.)
| | - Phillip J. Bergen
- Infection and Immunity Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (H.H.Y.); (M.A.K.A.); (J.Z.); (P.J.B.); (Y.Z.); (J.L.)
| | - Tony Velkov
- Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC 3053, Australia;
| | - Qi Tony Zhou
- Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 1047907, USA;
| | - Yan Zhu
- Infection and Immunity Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (H.H.Y.); (M.A.K.A.); (J.Z.); (P.J.B.); (Y.Z.); (J.L.)
| | - Jian Li
- Infection and Immunity Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (H.H.Y.); (M.A.K.A.); (J.Z.); (P.J.B.); (Y.Z.); (J.L.)
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9
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Vedelaar SR, Radzikowski JL, Heinemann M. A Robust Method for Generating, Quantifying, and Testing Large Numbers of Escherichia coli Persisters. Methods Mol Biol 2021; 2357:41-62. [PMID: 34590250 DOI: 10.1007/978-1-0716-1621-5_3] [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] [Indexed: 02/10/2024]
Abstract
Bacteria can exhibit phenotypes that render them tolerant against antibiotics. However, often only a few cells of a bacterial population show the so-called persister phenotype, which makes it difficult to study this health-threatening phenotype. We recently found that certain abrupt nutrient shifts generate Escherichia coli populations that consist almost entirely of antibiotic-tolerant cells. These nearly homogeneous persister cell populations enable assessment with population-averaging experimental methods, such as high-throughput methods. In this chapter, we provide a detailed protocol for generating a large fraction of tolerant cells using the nutrient-switch approach. Furthermore, we describe how to determine the fraction of cells that enter the tolerant state upon a sudden nutrient shift and we provide a new way to assess antibiotic tolerance using flow cytometry. We envision that these methods will facilitate research into the important and exciting phenotype of bacterial persister cells.
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Affiliation(s)
- Silke R Vedelaar
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Jakub L Radzikowski
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
- Centre for Engagement and Simulation Science (ICCESS), Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK
| | - Matthias Heinemann
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.
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10
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Karakonstantis S, Kritsotakis EI, Gikas A. Is pandrug-resistance in A. baumannii a transient phenotype? Epidemiological clues from a 4-year cohort study at a tertiary referral hospital in Greece. J Chemother 2020; 33:354-357. [PMID: 33124498 DOI: 10.1080/1120009x.2020.1839689] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Pandrug-resistant A. baumannii (PDRAB) is increasingly being reported but remains rare. Several case studies show that A. baumannii can acquire resistance to last resort antibiotics during treatment by single-step chromosomal mutations. However, re-emergence of the ancestral susceptible strain after withdrawal of antibiotics has been described, possibly due to fitness cost associated with acquired resistance. Therefore, PDRAB may be a transient phenotype. Epidemiological data to show this process in larger cohorts are currently lacking. In this study of 91 hospitalized patients with PDRAB we showed the frequent (60%) isolation of non-PDRAB, often susceptible only to colistin, aminoglycosides and/or tigecycline, preceding and/or following PDRAB isolation. However, the isolation of PDRAB in two outpatients, 25 and 36 days after their discharge from the hospital, suggests the potential of some PDRAB strains to persist even in the absence of antimicrobial pressure.
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Affiliation(s)
| | | | - Achilleas Gikas
- School of Medicine, University of Crete, Heraklion, Crete, Greece.,Infection Control Committee, University Hospital of Heraklion, Heraklion, Greece
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11
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Monem S, Furmanek-Blaszk B, Łupkowska A, Kuczyńska-Wiśnik D, Stojowska-Swędrzyńska K, Laskowska E. Mechanisms Protecting Acinetobacter baumannii against Multiple Stresses Triggered by the Host Immune Response, Antibiotics and Outside-Host Environment. Int J Mol Sci 2020; 21:E5498. [PMID: 32752093 PMCID: PMC7432025 DOI: 10.3390/ijms21155498] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 02/06/2023] Open
Abstract
Acinetobacter baumannii is considered one of the most persistent pathogens responsible for nosocomial infections. Due to the emergence of multidrug resistant strains, as well as high morbidity and mortality caused by this pathogen, A. baumannii was placed on the World Health Organization (WHO) drug-resistant bacteria and antimicrobial resistance research priority list. This review summarizes current studies on mechanisms that protect A. baumannii against multiple stresses caused by the host immune response, outside host environment, and antibiotic treatment. We particularly focus on the ability of A. baumannii to survive long-term desiccation on abiotic surfaces and the population heterogeneity in A. baumannii biofilms. Insight into these protective mechanisms may provide clues for the development of new strategies to fight multidrug resistant strains of A. baumannii.
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Affiliation(s)
- Soroosh Monem
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
| | - Beata Furmanek-Blaszk
- Department of Microbiology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland;
| | - Adrianna Łupkowska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
| | - Dorota Kuczyńska-Wiśnik
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
| | - Karolina Stojowska-Swędrzyńska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
| | - Ewa Laskowska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
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Karakonstantis S. A systematic review of implications, mechanisms, and stability of in vivo emergent resistance to colistin and tigecycline in Acinetobacter baumannii. J Chemother 2020; 33:1-11. [PMID: 32677578 DOI: 10.1080/1120009x.2020.1794393] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The potential of A. baumannii for acquired resistance to last resort antibiotics (colistin and tigecycline) during treatment has important clinical implications, especially when dealing with patients failing to improve despite treatment with an active antimicrobial. However, the relevant literature remains scattered. Therefore, a systematic search was conducted in PubMed and Scopus. Several studies reported emergence of resistance to colistin or tigecycline during treatment, in most cases (86%) resulting in persistent or recurrent infections, especially in cases of emergent resistance without fitness cost. Lipopolysaccharide modification in the case of colistin and overexpression of efflux pumps in the case of tigecycline were the main mechanisms of resistance. Emergent colistin resistance is often associated with fitness cost which may result in re-emergence of the fitter and more virulent colistin susceptible strain after cessation of antibiotic pressure. Prospective studies are needed to determine the frequency of emergent resistance during treatment and its impact on patient outcomes.
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Affiliation(s)
- Stamatis Karakonstantis
- Internal Medicine Department, General Hospital of Heraklion Venizeleio, Heraklion, Crete, Greece.,School of medicine, University of Crete, Heraklion, Crete, Greece
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