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Chen X, Zhao H, Wang C, Hamed M, Shang Q, Yang Y, Diao X, Sun X, Hu W, Jiang X, Zhang Y, Hirsch AKH, Wu D, Zhuang J. Two natural compounds as potential inhibitors against the Helicobacter pylori and Acinetobacter baumannii IspD enzymes. Int J Antimicrob Agents 2024; 63:107160. [PMID: 38537721 DOI: 10.1016/j.ijantimicag.2024.107160] [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: 12/30/2023] [Revised: 02/27/2024] [Accepted: 03/21/2024] [Indexed: 04/21/2024]
Abstract
In a vast majority of bacteria, protozoa and plants, the methylerythritol phosphate (MEP) pathway is utilized for the synthesis of isopentenyl diphosphate (IDP) and dimethylallyl diphosphate (DMADP), which are precursors for isoprenoids. Isoprenoids, such as cholesterol and coenzyme Q, play a variety of crucial roles in physiological activities, including cell-membrane formation, protein degradation, cell apoptosis, and transcription regulation. In contrast, humans employ the mevalonate (MVA) pathway for the production of IDP and DMADP, rendering proteins in the MEP pathway appealing targets for antimicrobial agents. This pathway consists of seven consecutive enzymatic reactions, of which 4-diphosphocytidyl-2C-methyl-D-erythritol synthase (IspD) and 2C-methyl-D-erythritol 2,4-cyclodiphosphate synthase (IspF) catalyze the third and fifth steps, respectively. In this study, we characterized the enzymatic activities and protein structures of Helicobacter pylori IspDF and Acinetobacter baumannii IspD. Then, using the direct interaction-based thermal shift assay, we conducted a compound screening of an approved drug library and identified 27 hit compounds potentially binding to AbIspD. Among them, two natural products, rosmarinic acid and tanshinone IIA sodium sulfonate, exhibited inhibitory activities against HpIspDF and AbIspD, by competing with one of the substrates, MEP. Moreover, tanshinone IIA sodium sulfonate also demonstrated certain antibacterial effects against H. pylori. In summary, we identified two IspD inhibitors from approved ingredients, broadening the scope for antibiotic discovery targeting the MEP pathway.
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Affiliation(s)
- Xiaoyu Chen
- Helmholtz International Lab, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Huilin Zhao
- Department of Pathogenic Biology, College of Basic Medicine, Binzhou Medical University, Yantai, China
| | - Chuandong Wang
- Helmholtz International Lab, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Mostafa Hamed
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI), Saarbrücken, Germany
| | - Qinghong Shang
- Helmholtz International Lab, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yating Yang
- Helmholtz International Lab, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xiaotong Diao
- Helmholtz International Lab, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xiangnan Sun
- Helmholtz International Lab, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Wei Hu
- Helmholtz International Lab, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xukai Jiang
- National Glycoengineering Research Center, Shandong University, Qingdao, China
| | - Youming Zhang
- Helmholtz International Lab, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Anna K H Hirsch
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI), Saarbrücken, Germany; Department of Pharmacy, Saarland University, Saarbrücken, Germany
| | - Dalei Wu
- Helmholtz International Lab, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.
| | - Jingjing Zhuang
- Helmholtz International Lab, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China; Marine College, Shandong University, Weihai, China.
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2
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Wang H, Ishchenko A, Skudlarek J, Shen P, Dzhekieva L, Painter RE, Chen YT, Bukhtiyarova M, Leithead A, Tracy R, Babaoglu K, Bahnck-Teets C, Buevich A, Cabalu TD, Labroli M, Lange H, Lei Y, Li W, Liu J, Mann PA, Meng T, Mitchell HJ, Mulhearn J, Scapin G, Sha D, Shaw AW, Si Q, Tong L, Wu C, Wu Z, Xiao JC, Xu M, Zhang LK, McKenney D, Miller RR, Black TA, Cooke A, Balibar CJ, Klein DJ, Raheem I, Walker SS. Cerastecins inhibit membrane lipooligosaccharide transport in drug-resistant Acinetobacter baumannii. Nat Microbiol 2024; 9:1244-1255. [PMID: 38649414 DOI: 10.1038/s41564-024-01667-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 03/06/2024] [Indexed: 04/25/2024]
Abstract
Carbapenem-resistant Acinetobacter baumannii infections have limited treatment options. Synthesis, transport and placement of lipopolysaccharide or lipooligosaccharide (LOS) in the outer membrane of Gram-negative bacteria are important for bacterial virulence and survival. Here we describe the cerastecins, inhibitors of the A. baumannii transporter MsbA, an LOS flippase. These molecules are potent and bactericidal against A. baumannii, including clinical carbapenem-resistant Acinetobacter baumannii isolates. Using cryo-electron microscopy and biochemical analysis, we show that the cerastecins adopt a serpentine configuration in the central vault of the MsbA dimer, stalling the enzyme and uncoupling ATP hydrolysis from substrate flipping. A derivative with optimized potency and pharmacokinetic properties showed efficacy in murine models of bloodstream or pulmonary A. baumannii infection. While resistance development is inevitable, targeting a clinically unexploited mechanism avoids existing antibiotic resistance mechanisms. Although clinical validation of LOS transport remains undetermined, the cerastecins may open a path to narrow-spectrum treatment modalities for important nosocomial infections.
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Affiliation(s)
- Hao Wang
- Merck & Co., Inc., West Point, PA, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Ying Lei
- Merck & Co., Inc., West Point, PA, USA
| | - Wei Li
- Merck & Co., Inc., West Point, PA, USA
| | - Jian Liu
- Merck & Co., Inc., West Point, PA, USA
| | | | - Tao Meng
- Merck & Co., Inc., Rahway, NJ, USA
| | | | | | | | - Deyou Sha
- Merck & Co., Inc., West Point, PA, USA
| | | | - Qian Si
- Merck & Co., Inc., West Point, PA, USA
| | - Ling Tong
- Merck & Co., Inc., West Point, PA, USA
| | | | - Zhe Wu
- Merck & Co., Inc., West Point, PA, USA
| | | | - Min Xu
- Merck & Co., Inc., West Point, PA, USA
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3
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Möller AM, Vázquez-Hernández M, Kutscher B, Brysch R, Brückner S, Marino EC, Kleetz J, Senges CHR, Schäkermann S, Bandow JE, Narberhaus F. Common and varied molecular responses of Escherichia coli to five different inhibitors of the lipopolysaccharide biosynthetic enzyme LpxC. J Biol Chem 2024; 300:107143. [PMID: 38458396 PMCID: PMC10998244 DOI: 10.1016/j.jbc.2024.107143] [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: 01/10/2024] [Revised: 02/19/2024] [Accepted: 02/21/2024] [Indexed: 03/10/2024] Open
Abstract
A promising yet clinically unexploited antibiotic target in difficult-to-treat Gram-negative bacteria is LpxC, the key enzyme in the biosynthesis of lipopolysaccharides, which are the major constituents of the outer membrane. Despite the development of dozens of chemically diverse LpxC inhibitor molecules, it is essentially unknown how bacteria counteract LpxC inhibition. Our study provides comprehensive insights into the response against five different LpxC inhibitors. All compounds bound to purified LpxC from Escherichia coli. Treatment of E. coli with these compounds changed the cell shape and stabilized LpxC suggesting that FtsH-mediated proteolysis of the inactivated enzyme is impaired. LpxC inhibition sensitized E. coli to vancomycin and rifampin, which poorly cross the outer membrane of intact cells. Four of the five compounds led to an accumulation of lyso-phosphatidylethanolamine, a cleavage product of phosphatidylethanolamine, generated by the phospholipase PldA. The combined results suggested an imbalance in lipopolysaccharides and phospholipid biosynthesis, which was corroborated by the global proteome response to treatment with the LpxC inhibitors. Apart from LpxC itself, FabA and FabB responsible for the biosynthesis of unsaturated fatty acids were consistently induced. Upregulated compound-specific proteins are involved in various functional categories, such as stress reactions, nucleotide, or amino acid metabolism and quorum sensing. Our work shows that antibiotics targeting the same enzyme do not necessarily elicit identical cellular responses. Moreover, we find that the response of E. coli to LpxC inhibition is distinct from the previously reported response in Pseudomonas aeruginosa.
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Affiliation(s)
- Anna-Maria Möller
- Microbial Biology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | | | - Blanka Kutscher
- Microbial Biology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Raffael Brysch
- Microbial Biology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Simon Brückner
- Microbial Biology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Emily C Marino
- Microbial Biology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Julia Kleetz
- Microbial Biology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Christoph H R Senges
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Sina Schäkermann
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Julia E Bandow
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Franz Narberhaus
- Microbial Biology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany.
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4
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Jo J, Lee JY, Cho H, Ko KS. Treatment of Colistin Dependence-Developing Acinetobacter baumannii with Antibiotic Combinations at Subinhibitory Concentrations. Microb Drug Resist 2023; 29:448-455. [PMID: 37379479 DOI: 10.1089/mdr.2022.0205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2023] Open
Abstract
Recent studies have revealed that colistin dependence frequently develops in colistin-susceptible Acinetobacter baumannii isolates. Despite resistance in parental strains, colistin-dependent mutants showed increased susceptibility to several antibiotics, which suggests the possibility of developing strategies to eliminate multidrug-resistant (MDR) A. baumannii. We investigated in vitro and in vivo efficacy of combinations of colistin and other antibiotics using MDR A. baumannii strains H08-391, H06-855, and H09-94, which are colistin-susceptible but develops colistin dependence upon exposure to colistin. An in vitro time-killing assay, a checkerboard assay, and an antibiotic treatment assay using Galleria mellonella larvae were performed. Although a single treatment of colistin at a high concentration did not prevent colistin dependence, combinations of colistin with other antibiotics at subinhibitory concentrations, especially amikacin, eradicated the strains by inhibiting the development of colistin dependence, in the in vitro time-killing assay. Only 40% of G. mellonella larvae infected by A. baumannii survived with colistin treatment alone; however, all or most of them survived following treatment with the combination of colistin and other antibiotics (amikacin, ceftriaxone, and tetracycline). Our results suggest the possibility of the combination of colistin and amikacin or other antibiotics as one of therapeutic options against A. baumannii infections by eliminating colistin-dependent mutants.
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Affiliation(s)
- Jeongwoo Jo
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Ji Young Lee
- Research Institute for Future Medical Science, Chungnam National University Sejong Hospital, Sejong, Republic of Korea
| | - Hongbaek Cho
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Republic of Korea
| | - Kwan Soo Ko
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
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5
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Paredes-Amaya CC, Ulloa MT, García-Angulo VA. Fierce poison to others: the phenomenon of bacterial dependence on antibiotics. J Biomed Sci 2023; 30:67. [PMID: 37574554 PMCID: PMC10424368 DOI: 10.1186/s12929-023-00963-x] [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: 04/25/2023] [Accepted: 08/07/2023] [Indexed: 08/15/2023] Open
Abstract
Beyond the development of resistance, the effects of antibiotics on bacteria and microbial communities are complex and far from exhaustively studied. In the context of the current global antimicrobial resistance crisis, understanding the adaptive and physiological responses of bacteria to antimicrobials is of paramount importance along with the development of new therapies. Bacterial dependence on antibiotics is a phenomenon in which antimicrobials instead of eliminating the pathogens actually provide a boost for their growth. This trait comprises an extreme example of the complexities of responses elicited by microorganisms to these drugs. This compelling evolutionary trait was readily described along with the first wave of antibiotics use and dependence to various antimicrobials has been reported. Nevertheless, current molecular characterizations have been focused on dependence on vancomycin, linezolid and colistin, three critically important antibiotics frequently used as last resource therapy for multi resistant pathogens. Outstanding advances have been made in understanding the molecular basis for the dependence to vancomycin, including specific mutations involved. Regarding linezolid and colistin, the general physiological components affected by the dependence, namely ribosomes and membrane function respectively, have been established. Nonetheless the implications of antibiotic dependence in clinically relevant features, such as virulence, epidemics, relationship with development of resistance, diagnostics and therapy effectiveness require clarification. This review presents a brief introduction of the phenomenon of bacterial dependence to antibiotics and a summary on early and current research concerning the basis for this trait. Furthermore, the available information on the effect of dependence in key clinical aspects is discussed. The studies performed so far underline the need to fully disclose the biological and clinical significance of this trait in pathogens to successfully assess its role in resistance and to design adjusted therapies.
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Affiliation(s)
- Claudia C Paredes-Amaya
- Microbiology Department, Escuela de Ciencias Básicas, Facultad de Salud, Universidad del Valle, Cali, Colombia
| | - María Teresa Ulloa
- Microbiology and Micology Program, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Independencia 1027, Independencia, RM, Santiago, Chile
- Vertebral I+D+i - Corporation for Assistance for Burned Children (Coaniquem), Santiago, Chile
| | - Víctor Antonio García-Angulo
- Microbiology and Micology Program, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Independencia 1027, Independencia, RM, Santiago, Chile.
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6
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Yekani M, Azargun R, Sharifi S, Nabizadeh E, Nahand JS, Ansari NK, Memar MY, Soki J. Collateral sensitivity: An evolutionary trade-off between antibiotic resistance mechanisms, attractive for dealing with drug-resistance crisis. Health Sci Rep 2023; 6:e1418. [PMID: 37448730 PMCID: PMC10336338 DOI: 10.1002/hsr2.1418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 06/29/2023] [Accepted: 06/29/2023] [Indexed: 07/15/2023] Open
Abstract
Background The discovery and development of antimicrobial drugs were one of the most significant advances in medicine, but the evolution of microbial resistance limited the efficiency of these drugs. Aim This paper reviews the collateral sensitivity in bacteria and its potential and limitation as a new target for treating infections. Results and Discussion Knowledge mechanisms of resistance to antimicrobial agents are useful to trace a practical approach to treat and control of resistant pathogens. The effect of a resistance mechanism to certain antibiotics on the susceptibility or resistance to other drugs is a key point that may be helpful for applying a strategy to control resistance challenges. In an evolutionary trade-off known as collateral sensitivity, the resistance mechanism to a certain drug may be mediated by the hypersensitivity to other drugs. Collateral sensitivity has been described for different drugs in various bacteria, but the molecular mechanisms affecting susceptibility are not well demonstrated. Collateral sensitivity could be studied to detect its potential in the battle against resistance crisis as well as in the treatment of pathogens adapting to antibiotics. Collateral sensitivity-based antimicrobial therapy may have the potential to limit the emergence of antibiotic resistance.
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Affiliation(s)
- Mina Yekani
- Department of Microbiology, Faculty of MedicineKashan University of Medical SciencesKashanIran
- Infectious and Tropical Diseases Research CenterTabriz University of Medical SciencesTabrizIran
- Student Research CommitteeKashan University of Medical SciencesKashanIran
| | - Robab Azargun
- Department of Microbiology, Faculty of MedicineMaragheh University of Medical ScienceMaraghehIran
| | - Simin Sharifi
- Dental and Periodontal Research CenterTabriz University of Medical SciencesTabrizIran
| | - Edris Nabizadeh
- Infectious and Tropical Diseases Research CenterTabriz University of Medical SciencesTabrizIran
| | - Javid Sadri Nahand
- Infectious and Tropical Diseases Research CenterTabriz University of Medical SciencesTabrizIran
| | - Navideh Karimi Ansari
- Department of Microbiology, Faculty of MedicineTabriz University of Medical SciencesTabrizIran
| | - Mohammad Yousef Memar
- Infectious and Tropical Diseases Research CenterTabriz University of Medical SciencesTabrizIran
| | - Jozsef' Soki
- Institute of Medical Microbiology, Albert Szent‐Györgyi Faculty of MedicineUniversity of SzegedSzegedHungary
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7
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Ham SL, Lee TH, Kim KJ, Kim JH, Hwang SJ, Lee SH, Yu JS, Kim KH, Lee HJ, Lee W, Kim CS. Discovery and Biosynthesis of Imidazolium Antibiotics from the Probiotic Bacillus licheniformis. JOURNAL OF NATURAL PRODUCTS 2023; 86:850-859. [PMID: 36921254 DOI: 10.1021/acs.jnatprod.2c01032] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Antibiotic resistance is one of the world's most urgent public health problems, and novel antibiotics to kill drug-resistant bacteria are needed. Natural product-derived small molecules have been the major source of new antibiotics. Here we describe a family of antibacterial metabolites isolated from a probiotic bacterium, Bacillus licheniformis. A cross-streaking assay followed by activity-guided isolation yielded a novel antibacterial metabolite, bacillimidazole G, which possesses a rare imidazolium ring in the structure, showing MIC values of 0.7-2.6 μg/mL against human pathogenic Gram-positive and Gram-negative bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and a lipopolysaccharide (LPS)-lacking Acinetobacter baumannii ΔlpxC. Bacillimidazole G also lowered MICs of colistin, a Gram-negative antibiotic, up to 8-fold against wild-type Escherichia coli MG1655 and A. baumannii. We propose a biosynthetic pathway to the characterized metabolites based on precursor-feeding studies, a chemical biological approach, biomimetic total synthesis, and a biosynthetic gene knockout method.
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Affiliation(s)
- Song Lim Ham
- Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Tae Hyun Lee
- Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Kyung Jun Kim
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jung Ha Kim
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Su Jung Hwang
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Sun Ho Lee
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jae Sik Yu
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Integrative Biological Sciences and Industry, Sejong University, Seoul 05006, Republic of Korea
| | - Ki Hyun Kim
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Hyo-Jong Lee
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Wonsik Lee
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Chung Sub Kim
- Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
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Antimicrobial Susceptibility Testing Performed in RPMI 1640 Reveals Azithromycin Efficacy against Carbapenem-Resistant Acinetobacter baumannii and Predicts In Vivo Outcomes in Galleria mellonella. Antimicrob Agents Chemother 2023; 67:e0132022. [PMID: 36468875 PMCID: PMC9872712 DOI: 10.1128/aac.01320-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022] Open
Abstract
Antimicrobial susceptibility testing (AST) in RPMI 1640, a more physiologically relevant culture medium, revealed that a substantial proportion of carbapenem-resistant Acinetobacter baumannii isolates were susceptible to azithromycin, a macrolide antibiotic not currently considered effective against A. baumannii. Experiments using Galleria mellonella validated these in vitro data. Our finding that RPMI 1640's predictive accuracy for in vivo outcomes is superior to that of Mueller-Hinton II broth also supports the use of more physiologically relevant AST culturing conditions.
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9
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Möller AM, Brückner S, Tilg LJ, Kutscher B, Nowaczyk MM, Narberhaus F. LapB (YciM) orchestrates protein-protein interactions at the interface of lipopolysaccharide and phospholipid biosynthesis. Mol Microbiol 2023; 119:29-43. [PMID: 36464488 DOI: 10.1111/mmi.15005] [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: 09/29/2022] [Revised: 11/14/2022] [Accepted: 11/14/2022] [Indexed: 11/23/2022]
Abstract
The outer membrane (OM) of Gram-negative bacteria functions as an essential barrier and is characterized by an asymmetric bilayer with lipopolysaccharide (LPS) in the outer leaflet. The enzyme LpxC catalyzes the first committed step in LPS biosynthesis. It plays a critical role in maintaining the balance between LPS and phospholipids (PL), which are both derived from the same biosynthetic precursor. The essential inner membrane proteins YejM (PbgA, LapC), LapB (YciM), and the protease FtsH are known to account for optimal LpxC levels, but the mechanistic details are poorly understood. LapB is thought to be a bi-functional protein serving as an adaptor for FtsH-mediated turnover of LpxC and acting as a scaffold in the coordination of LPS biosynthesis. Here, we provide experimental evidence for the physical interaction of LapB with proteins at the biosynthetic node from where the LPS and PL biosynthesis pathways diverge. By a total of four in vivo and in vitro assays, we demonstrate protein-protein interactions between LapB and the LPS biosynthesis enzymes LpxA, LpxC, and LpxD, between LapB and YejM, the anti-adaptor protein regulating LapB activity, and between LapB and FabZ, the first PL biosynthesis enzyme. Moreover, we uncovered a new adaptor function of LapB in destabilizing not only LpxC but also LpxD. Overall, our study shows that LapB is a multi-functional protein that serves as a protein-protein interaction hub for key enzymes in LPS and PL biogenesis presumably by virtue of multiple tetratricopeptide repeat (TPR) motifs in its cytoplasmic C-terminal region.
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Affiliation(s)
| | - Simon Brückner
- Microbial Biology, Ruhr University Bochum, Bochum, Germany
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10
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Yoshida I, Takata I, Fujita K, Takashima H, Sugiyama H. TP0586532, a Novel Non-Hydroxamate LpxC Inhibitor: Potentiating Effect on In Vitro Activity of Meropenem against Carbapenem-Resistant Enterobacteriaceae. Microbiol Spectr 2022; 10:e0082822. [PMID: 35647694 PMCID: PMC9241751 DOI: 10.1128/spectrum.00828-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/10/2022] [Indexed: 12/31/2022] Open
Abstract
Carbapenem-resistant Enterobacteriaceae (CRE) are an urgent threat to public health requiring the development of novel therapies. TP0586532 is a novel non-hydroxamate LpxC inhibitor that inhibits the synthesis of lipopolysaccharides, which are components of the outer membranes of Gram-negative bacteria. Based on the mechanism of action of TP0586532, we hypothesized that it might enhance the antibacterial activity of other antibiotics by increasing the permeability of the outer bacterial membrane. The combination of TP0586532 with meropenem, amikacin, cefepime, piperacillin, and tigecycline showed synergistic and additive effects against carbapenem-susceptible Klebsiella pneumoniae and Escherichia coli. Checkerboard experiments against 21 carbapenem-resistant K. pneumoniae and E. coli strains (13 blaKPC+, 5 blaNDM-1+, 2 blaVIM+, and 1 blaIMP+) showed that the combination of TP0586532 with meropenem yielded synergistic and additive effects against 9 and 12 strains, respectively. In a time-kill assay examining 12 CRE strains, synergistic effects were observed when TP0586532 was combined with meropenem against many of the strains. A membrane permeability assay using ethidium bromide (EtBr) was performed to investigate the mechanism of the potentiating effect. TP0586532 increased the influx of EtBr into a CRE strain, suggesting that TP0586532 increased membrane permeability and facilitated intracellular access for the antibiotics. Our study demonstrates that TP0586532 potentiates the in vitro antibacterial activity of meropenem against CRE. Combination therapy consisting of TP0586532 and meropenem has potential as a treatment for CRE infections. IMPORTANCE Carbapenem-resistant Enterobacteriaceae (CRE) are an urgent public health threat, as therapeutic options are limited. TP0586532 is a novel LpxC inhibitor that inhibits the synthesis of lipopolysaccharides in the outer membranes of Gram-negative bacteria. Here, we demonstrated the potentiating effects of TP0586532 on the antibacterial activity of meropenem against CRE harboring various types of carbapenemase genes (blaKPC+, blaNDM-1+ blaVIM+, and blaIMP+). TP0586532 also augmented the bactericidal effects of meropenem against CRE strains, even against those with a high level of resistance to meropenem. The potentiating effects were suggested to be mediated by an increase in bacterial membrane permeability. Our study revealed that a combination therapy consisting of TP0586532 and meropenem has the potential to be a novel therapeutic option for CRE infections.
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Affiliation(s)
- Ippei Yoshida
- Pharmacology Laboratories, Taisho Pharmaceutical Co., Ltd., Saitama, Japan
| | - Iichiro Takata
- Pharmacology Laboratories, Taisho Pharmaceutical Co., Ltd., Saitama, Japan
| | - Kiyoko Fujita
- Pharmacology Laboratories, Taisho Pharmaceutical Co., Ltd., Saitama, Japan
| | - Hajime Takashima
- Chemistry Laboratories, Taisho Pharmaceutical Co., Ltd., Saitama, Japan
| | - Hiroyuki Sugiyama
- Pharmacology Laboratories, Taisho Pharmaceutical Co., Ltd., Saitama, Japan
- Medical Information, Taisho Pharmaceutical Co., Ltd., Tokyo, Japan
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11
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Fujita K, Takata I, Yoshida I, Honma Y, Okumura H, Otake K, Takashima H, Sugiyama H. Pharmacodynamic target assessment and prediction of clinically effective dosing regimen of TP0586532, a novel non-hydroxamate LpxC inhibitor, using a murine lung infection model. J Infect Chemother 2022; 28:635-642. [DOI: 10.1016/j.jiac.2022.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 12/24/2021] [Accepted: 01/12/2022] [Indexed: 11/26/2022]
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12
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Fujita K, Takata I, Yoshida I, Okumura H, Otake K, Takashima H, Sugiyama H. TP0586532, a non-hydroxamate LpxC inhibitor, has in vitro and in vivo antibacterial activities against Enterobacteriaceae. J Antibiot (Tokyo) 2022; 75:98-107. [PMID: 34837061 DOI: 10.1038/s41429-021-00486-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/15/2021] [Accepted: 10/06/2021] [Indexed: 02/08/2023]
Abstract
The emergence of multi-drug resistant pathogenic bacteria, especially Gram-negative bacteria, is a worldwide health problem. New antibiotics directed at previously unexplored targets are urgently needed to overcome resistance to existing antibiotic classes. UDP-3-O-acyl-N-acetylglucosamine deacetylase (LpxC) is an attractive target for a new antibacterial agent. Although a number of LpxC inhibitors have been identified, none have been approved as antibacterial agents. These LpxC inhibitors contain a hydroxamate moiety, which is a robust zinc ion chelator. The nonspecific inhibition of metalloenzymes through zinc ion chelation is one of possibilities leading to unwanted side effects. Herein, we report that TP0586532, a non-hydroxamate LpxC inhibitor, has a broad spectrum of antibacterial activity against carbapenem-resistant Enterobacteriaceae. The MIC90 of TP0586532 against clinical isolates of carbapenem-resistant Klebsiella pneumoniae was 4 μg ml-1. TP0586532 also showed an in vivo efficacy against murine systemic, urinary tract and lung infection models caused by meropenem- or ciprofloxacin-resistant strains. The estimated maximum unbound plasma concentration value at the effective dose of TP0586532 in murine infection models was around 13 μg ml-1. TP0586532 is predicted to exhibit a in vivo efficacy without cardiovascular toxicity and showed the potential of non-hydroxamate LpxC inhibitors as antibacterial agents against carbapenem-resistant Enterobacteriaceae.
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Kon H, Hameir A, Temkin E, Keren-Paz A, Schwartz D, Schechner V, Carmeli Y. Colistin Dependency among Colistin-Heteroresistant Acinetobacter baumannii Isolates. Microorganisms 2021; 10:58. [PMID: 35056508 PMCID: PMC8780235 DOI: 10.3390/microorganisms10010058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/23/2021] [Accepted: 12/26/2021] [Indexed: 11/16/2022] Open
Abstract
Colistin dependent (CD) isolates are dependent on colistin for optimal growth. Here we aimed to systematically determine the emergence of CD among colistin-heteroresistant carbapenem-resistant Acinetobacter baumannii (CRAB) isolates. We also examined the phenotypic characteristics of CD and the evolution of CD strains to overt resistance. Additionally, we examined whether detection of growth in blood cultures was impaired by CD. Heteroresistant isolates, as determined by population analysis profiling, were exposed to colistin; when the colony count with colistin was significantly higher than without, isolates were suspected to be CD. CD was confirmed by Etest and growth curves. CD strains with colistin minimum inhibitory concentrations > 2 mg/L after growth in colistin-free media were considered colistin-resistant. Of the 65 heteroresistant strains tested, eight became CD after colistin exposure. These strains attained higher colony counts and growth rates with colistin vs. without, and grew adjacent to the colistin Etest strip. CD strains exhibited increased susceptibilities to multiple antibiotics compared to their parent heteroresistant strains. All CD strains tested became colistin-resistant following growth without colistin. CD strains were detected in blood culture bottles, but time to detection was significantly prolonged compared with parent strains, suggesting that CD may lead to delay in detection of CRAB bacteremia.
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Affiliation(s)
- Hadas Kon
- National Institute for Antibiotic Resistance and Infection Control, Ministry of Health, Tel Aviv 6423906, Israel; (H.K.); (A.H.); (E.T.); (A.K.-P.); (D.S.); (V.S.)
| | - Amichay Hameir
- National Institute for Antibiotic Resistance and Infection Control, Ministry of Health, Tel Aviv 6423906, Israel; (H.K.); (A.H.); (E.T.); (A.K.-P.); (D.S.); (V.S.)
| | - Elizabeth Temkin
- National Institute for Antibiotic Resistance and Infection Control, Ministry of Health, Tel Aviv 6423906, Israel; (H.K.); (A.H.); (E.T.); (A.K.-P.); (D.S.); (V.S.)
| | - Alona Keren-Paz
- National Institute for Antibiotic Resistance and Infection Control, Ministry of Health, Tel Aviv 6423906, Israel; (H.K.); (A.H.); (E.T.); (A.K.-P.); (D.S.); (V.S.)
| | - David Schwartz
- National Institute for Antibiotic Resistance and Infection Control, Ministry of Health, Tel Aviv 6423906, Israel; (H.K.); (A.H.); (E.T.); (A.K.-P.); (D.S.); (V.S.)
| | - Vered Schechner
- National Institute for Antibiotic Resistance and Infection Control, Ministry of Health, Tel Aviv 6423906, Israel; (H.K.); (A.H.); (E.T.); (A.K.-P.); (D.S.); (V.S.)
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yehuda Carmeli
- National Institute for Antibiotic Resistance and Infection Control, Ministry of Health, Tel Aviv 6423906, Israel; (H.K.); (A.H.); (E.T.); (A.K.-P.); (D.S.); (V.S.)
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
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14
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Wang X, Loh B, Altamirano FG, Yu Y, Hua X, Leptihn S. Colistin- phage combinations decrease antibiotic resistance in A. baumannii via changes in envelope architecture. Emerg Microbes Infect 2021; 10:2205-2219. [PMID: 34736365 PMCID: PMC8648044 DOI: 10.1080/22221751.2021.2002671] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Multidrug-resistant bacterial infections are becoming increasingly common, with only few last-resort antibiotics such as colistin available for clinical therapy. An alternative therapeutic strategy gaining momentum is phage therapy, which has the advantage of not being affected by bacterial resistance to antibiotics. However, a major challenge in phage therapy is the rapid emergence of phage-resistant bacteria. In this work, our main aim was to understand the mechanisms of phage-resistance used by the top priority pathogen Acinetobacter baumannii. We isolated the novel phage Phab24, capable of infecting colistin-sensitive and -resistant strains of A. baumannii. After co-incubating Phab24 with its hosts, we obtained phage-resistant mutants which were characterized on both genotypic and phenotypic levels. Using whole genome sequencing, we identified phage-resistant strains that displayed mutations in genes that alter the architecture of the bacterial envelope at two levels: the capsule and the outer membrane. Using an adsorption assay, we confirmed that phage Phab24 uses the bacterial capsule as its primary receptor, with the outer membrane possibly serving as the secondary receptor. Interestingly, the phage-resistant isolates were less virulent compared to the parental strains in a Galleria mellonella infection model. Most importantly, we observed that phage-resistant bacteria that evolved in the absence of antibiotics exhibited an increased sensitivity to colistin, even though the antibiotic resistance mechanism per se remained unaltered. This increase in antibiotic sensitivity is a direct consequence of the phage-resistance mechanism, and could potentially be exploited in the clinical setting.
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Affiliation(s)
- Xiaoqing Wang
- Zhejiang University-University of Edinburgh (ZJU-UoE) Institute, Zhejiang University, Haining, China.,Medical school, Lishui University, Lishui, China
| | | | - Fernando Gordillo Altamirano
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia.,Centre to Impact AMR, Monash University, Clayton, Victoria, Australia
| | - Yunsong Yu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China .,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Xiaoting Hua
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China .,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Sebastian Leptihn
- Zhejiang University-University of Edinburgh (ZJU-UoE) Institute, Zhejiang University, Haining, China.,Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China .,University of Edinburgh Medical School, Biomedical Sciences, College of Medicine & Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
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15
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Olmeda-López H, Corral-Lugo A, McConnell MJ. Effect of Subinhibitory Concentrations of Antibiotics and Disinfectants on IS Aba-Mediated Inactivation of Lipooligosaccharide Biosynthesis Genes in Acinetobacter baumannii. Antibiotics (Basel) 2021; 10:antibiotics10101259. [PMID: 34680840 PMCID: PMC8532902 DOI: 10.3390/antibiotics10101259] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 10/13/2021] [Accepted: 10/14/2021] [Indexed: 01/03/2023] Open
Abstract
Inactivation of the lipooligosaccharide (LOS) biosynthesis genes lpxA, lpxC and lpxD by ISAba insertion elements results in high-level resistance to colistin in A. baumannii. In the present study, we quantify the rate of spontaneous insertional inactivation of LOS biosynthesis genes by ISAba elements in the ATCC 19606-type strain and two multidrug clinical isolates. Using insertional inactivation of lpxC by ISAba11 in the ATCC 19606 strain as a model, we determine the effect of several subinhibitory concentrations of the antibiotics, namely tetracycline, ciprofloxacin, meropenem, kanamycin and rifampicin, as well as the disinfectants ethanol and chlorhexidine on ISAba11 insertion frequencies. Notably, subinhibitory concentrations of tetracycline significantly increased ISAba11 insertion, and rifampicin completely inhibited the emergence of colistin resistance due to ISAba11 inactivation of lpxC. Sequencing of ISAba11 insertion sites within the lpxC gene demonstrated that insertions clustered between nucleotides 382 and 618 (58.3% of unique insertions detected), indicating that this may be a hotspot for ISAba11 insertion. The alignment of insertion sites revealed a semi-conserved AT-rich consensus sequence upstream of the ISAba11 insertion site, suggesting that ISAba11 insertion sites may be sequence-dependent. This study explores previously uncharacterized aspects regarding the acquisition of colistin resistance through insertional activation in LOS biosynthesis genes in A. baumannii.
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16
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Affiliation(s)
| | - Dan I. Andersson
- Uppsala University, Department of Medical Biochemistry and Microbiology, Uppsala, Sweden
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17
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North OI, Brown ED. Phage-antibiotic combinations: a promising approach to constrain resistance evolution in bacteria. Ann N Y Acad Sci 2020; 1496:23-34. [PMID: 33175408 DOI: 10.1111/nyas.14533] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 10/15/2020] [Accepted: 10/26/2020] [Indexed: 12/18/2022]
Abstract
Antibiotic resistance has reached dangerously high levels throughout the world. A growing number of bacteria pose an urgent, serious, and concerning threat to public health. Few new antibiotics are available to clinicians and only few are in development, highlighting the need for new strategies to overcome the antibiotic resistance crisis. Combining existing antibiotics with phages, viruses the infect bacteria, is an attractive and promising alternative to standalone therapies. Phage-antibiotic combinations have been shown to suppress the emergence of resistance in bacteria, and sometimes even reverse it. Here, we discuss the mechanisms by which phage-antibiotic combinations reduce resistance evolution, and the potential limitations these mechanisms have in steering microbial resistance evolution in a desirable direction. We also emphasize the importance of gaining a better understanding of mechanisms behind physiological and evolutionary phage-antibiotic interactions in complex in-patient environments.
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Affiliation(s)
- Olesia I North
- Department of Biochemistry and Biomedical Sciences and M.G. DeGroote Institute for Infectious Disease Research, McMaster University, Ontario, Canada
| | - Eric D Brown
- Department of Biochemistry and Biomedical Sciences and M.G. DeGroote Institute for Infectious Disease Research, McMaster University, Ontario, Canada
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18
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Jiang X, Yang K, Han ML, Yuan B, Li J, Gong B, Velkov T, Schreiber F, Wang L, Li J. Outer Membranes of Polymyxin-Resistant Acinetobacter baumannii with Phosphoethanolamine-Modified Lipid A and Lipopolysaccharide Loss Display Different Atomic-Scale Interactions with Polymyxins. ACS Infect Dis 2020; 6:2698-2708. [PMID: 32871077 DOI: 10.1021/acsinfecdis.0c00330] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Resistance to the last-line polymyxins is increasingly reported in multidrug-resistant Gram-negative pathogens, including Acinetobacter baumannii, which develops resistance via either lipid A modification (e.g., with phosphoethanolamine [pEtN]) or even lipopolysaccharide (LPS) loss in the outer membrane (OM). Considering these two different mechanisms, quantitative membrane lipidomics data were utilized to develop three OM models representing polymyxin-susceptible and -resistant A. baumannii strains. Through all-atom molecular simulations with enhanced sampling techniques, the effect of lipid A-pEtN modification and LPS loss on the action of colistin (i.e., polymyxin E) was examined for the first time, with a focus on the dynamics and energetics of colistin penetration into these OMs. Lipid A-pEtN modification improved the OM stability, impeding the penetration of colistin into the OM; this differed from the current literature that lipid A-pEtN modification confers resistance by diminishing the initial interaction with polymyxins. In contrast, the LPS deficiency significantly reduced the negative charges on the OM surface, diminishing the binding of colistin. Moreover, both lipid A-pEtN modification and LPS loss also constituted colistin resistance through disturbing the conformational transitions of the colistin molecule. Collectively, atomic-scale interactions between polymyxins and different bacterial OMs are very different and the findings may facilitate the discovery of new-generation polymyxins against Gram-negative 'superbugs'.
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Affiliation(s)
- Xukai Jiang
- Biomedicine Discovery Institute, Infection & Immunity Program, Department of Microbiology, Monash University, Melbourne, VIC 3800, Australia
| | - Kai Yang
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| | - Mei-Ling Han
- Biomedicine Discovery Institute, Infection & Immunity Program, Department of Microbiology, Monash University, Melbourne, VIC 3800, Australia
| | - Bing Yuan
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| | - Jingliang Li
- Institute for Frontier Materials, Deakin University, Geelong, VIC 3217, Australia
| | - Bin Gong
- School of Software, Shandong University, Jinan 250101, China
| | - Tony Velkov
- Department of Pharmacology & Therapeutics, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Falk Schreiber
- Department of Computer and Information Science, University of Konstanz, Konstanz 78467, Germany
| | - Lushan Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Jian Li
- Biomedicine Discovery Institute, Infection & Immunity Program, Department of Microbiology, Monash University, Melbourne, VIC 3800, Australia
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19
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Antimicrobial Peptide Exposure Selects for Resistant and Fit Stenotrophomonas maltophilia Mutants That Show Cross-Resistance to Antibiotics. mSphere 2020; 5:5/5/e00717-20. [PMID: 32999081 PMCID: PMC7529437 DOI: 10.1128/msphere.00717-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antimicrobial peptides (AMPs) are essential components of the innate immune system and have been proposed as promising therapeutic agents against drug-resistant microbes. AMPs possess a rapid bactericidal mode of action and can interact with different targets, but bacteria can also avoid their effect through a variety of resistance mechanisms. Apart from hampering treatment by the AMP itself, or that by other antibiotics in the case of cross-resistance, AMP resistance might also confer cross-resistance to innate human peptides and impair the anti-infective capability of the human host. A better understanding of how resistance to AMPs is acquired and the genetic mechanisms involved is needed before using these compounds as therapeutic agents. Using experimental evolution and whole-genome sequencing, we determined the genetic causes and the effect of acquired de novo resistance to three different AMPs in the opportunistic pathogen Stenotrophomonas maltophilia, a bacterium that is intrinsically resistant to a wide range of antibiotics. Our results show that AMP exposure selects for high-level resistance, generally without any reduction in bacterial fitness, conferred by mutations in different genes encoding enzymes, transporters, transcriptional regulators, and other functions. Cross-resistance to AMPs and to other antibiotic classes not used for selection, as well as collateral sensitivity, was observed for many of the evolved populations. The relative ease by which high-level AMP resistance is acquired, combined with the occurrence of cross-resistance to conventional antibiotics and the maintained bacterial fitness of the analyzed mutants, highlights the need for careful studies of S. maltophilia resistance evolution to clinically valuable AMPs.IMPORTANCE Stenotrophomonas maltophilia is an increasingly relevant multidrug-resistant (MDR) bacterium found, for example, in people with cystic fibrosis and associated with other respiratory infections and underlying pathologies. The infections caused by this nosocomial pathogen are difficult to treat due to the intrinsic resistance of this bacterium against a broad number of antibiotics. Therefore, new treatment options are needed, and considering the growing interest in using AMPs as alternative therapeutic compounds and the restricted number of antibiotics active against S. maltophilia, we addressed the potential for development of AMP resistance, the genetic mechanisms involved, and the physiological effects that acquisition of AMP resistance has on this opportunistic pathogen.
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20
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Impey RE, Hawkins DA, Sutton JM, Soares da Costa TP. Overcoming Intrinsic and Acquired Resistance Mechanisms Associated with the Cell Wall of Gram-Negative Bacteria. Antibiotics (Basel) 2020; 9:E623. [PMID: 32961699 PMCID: PMC7558195 DOI: 10.3390/antibiotics9090623] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/16/2020] [Accepted: 09/17/2020] [Indexed: 12/19/2022] Open
Abstract
The global increase in multi-drug-resistant bacteria is severely impacting our ability to effectively treat common infections. For Gram-negative bacteria, their intrinsic and acquired resistance mechanisms are heightened by their unique cell wall structure. The cell wall, while being a target of some antibiotics, represents a barrier due to the inability of most antibacterial compounds to traverse and reach their intended target. This means that its composition and resulting mechanisms of resistance must be considered when developing new therapies. Here, we discuss potential antibiotic targets within the most well-characterised resistance mechanisms associated with the cell wall in Gram-negative bacteria, including the outer membrane structure, porins and efflux pumps. We also provide a timely update on the current progress of inhibitor development in these areas. Such compounds could represent new avenues for drug discovery as well as adjuvant therapy to help us overcome antibiotic resistance.
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Affiliation(s)
- Rachael E. Impey
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia; (R.E.I.); (D.A.H.)
| | - Daniel A. Hawkins
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia; (R.E.I.); (D.A.H.)
| | - J. Mark Sutton
- National Infection Service, Research and Development Institute, Public Health England, Porton Down, Salisbury, Wiltshire SP4 0JG, UK;
| | - Tatiana P. Soares da Costa
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia; (R.E.I.); (D.A.H.)
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21
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Zhu Y, Lu J, Han M, Jiang X, Azad MAK, Patil NA, Lin Y, Zhao J, Hu Y, Yu HH, Chen K, Boyce JD, Dunstan RA, Lithgow T, Barlow CK, Li W, Schneider‐Futschik EK, Wang J, Gong B, Sommer B, Creek DJ, Fu J, Wang L, Schreiber F, Velkov T, Li J. Polymyxins Bind to the Cell Surface of Unculturable Acinetobacter baumannii and Cause Unique Dependent Resistance. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2000704. [PMID: 32775156 PMCID: PMC7403960 DOI: 10.1002/advs.202000704] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/28/2020] [Indexed: 05/13/2023]
Abstract
Multidrug-resistant Acinetobacter baumannii is a top-priority pathogen globally and polymyxins are a last-line therapy. Polymyxin dependence in A. baumannii (i.e., nonculturable on agar without polymyxins) is a unique and highly-resistant phenotype with a significant potential to cause treatment failure in patients. The present study discovers that a polymyxin-dependent A. baumannii strain possesses mutations in both lpxC (lipopolysaccharide biosynthesis) and katG (reactive oxygen species scavenging) genes. Correlative multiomics analyses show a significantly remodeled cell envelope and remarkably abundant phosphatidylglycerol in the outer membrane (OM). Molecular dynamics simulations and quantitative membrane lipidomics reveal that polymyxin-dependent growth emerges only when the lipopolysaccharide-deficient OM distinctively remodels with ≥ 35% phosphatidylglycerol, and with "patch" binding on the OM by the rigid polymyxin molecules containing strong intramolecular hydrogen bonding. Rather than damaging the OM, polymyxins bind to the phosphatidylglycerol-rich OM and strengthen the membrane integrity, thereby protecting bacteria from external reactive oxygen species. Dependent growth is observed exclusively with polymyxin analogues, indicating a critical role of the specific amino acid sequence of polymyxins in forming unique structures for patch-binding to bacterial OM. Polymyxin dependence is a novel antibiotic resistance mechanism and the current findings highlight the risk of 'invisible' polymyxin-dependent isolates in the evolution of resistance.
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Affiliation(s)
- Yan Zhu
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Jing Lu
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Mei‐Ling Han
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Xukai Jiang
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Mohammad A. K. Azad
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Nitin A. Patil
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Yu‐Wei Lin
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Jinxin Zhao
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Yang Hu
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Heidi H. Yu
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Ke Chen
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - John D. Boyce
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Rhys A. Dunstan
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Trevor Lithgow
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | | | - Weifeng Li
- School of Physics and State Key Laboratory of Crystal MaterialsShandong UniversityJinan250100China
| | | | - Jiping Wang
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Bin Gong
- School of Computer Science and TechnologyShandong UniversityJinan250100China
| | - Bjorn Sommer
- Department of Computer and Information ScienceUniversity of KonstanzKonstanz78457Germany
| | - Darren J. Creek
- Drug Delivery, Disposition and DynamicsMonash Institute of Pharmaceutical SciencesMonash UniversityMelbourne3052Australia
| | - Jing Fu
- Department of Mechanical and Aerospace EngineeringMonash UniversityMelbourne3800Australia
| | - Lushan Wang
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao CampusQingdao266237China
| | - Falk Schreiber
- Department of Computer and Information ScienceUniversity of KonstanzKonstanz78457Germany
| | - Tony Velkov
- Department of Pharmacology and TherapeuticsUniversity of MelbourneMelbourne3010Australia
| | - Jian Li
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
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22
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Gazel D, Tatman Otkun M, Akçalı A. In vitro activity of methylene blue and eosin methylene blue agar on colistin-resistant A. baumannii: an experimental study. J Med Microbiol 2019; 68:1607-1613. [PMID: 31535963 DOI: 10.1099/jmm.0.001078] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Introduction. Colistin is a last-resort antibiotic used against carbapenem-resistant Acinetobacter baumannii (AB); however, colistin resistance has been reported recently. Methylene blue (MB) is used in microbiology for staining, and in medicine as an antidote drug.Aim. We aimed to investigate the antimicrobial effects of MB and eosin methylene blue (EMB) agar against colistin-resistant AB strains.Methodology. Firstly, a standard strain and AB clinical isolate were included in the study. After determining MICs, two strains were transformed into colistin-resistant forms, using Li's method. At each step, new MICs were determined and subcultures were inoculated onto EMB and sheep blood agar (SBA). Colistin MICs of the subcultures were also determined using Mueller-Hinton agar (MHA) containing MB. Secondly, colistin-resistant clones from 31 multidrug-resistant AB clinical isolates were screened to investigate their susceptibilities to EMB agar.Results. In the first round, MICs of both strains had risen to 64 μg ml-1. Subpopulations with high colistin resistance were inhibited by MB and EMB agar, but could grow well on SBA. In MHA plates containing MB, the MICs decreased to 0.5 μg ml-1 for colistin-susceptible or moderately resistant clones. Additionally, clones with high colistin resistance showed atypical colony morphology on SBA. In the second round, 35 % of the clinical isolates, which had gained resistance to colistin, were inhibited by EMB agar.Conclusion. MB may have inhibitory effects against colistin-resistant AB. Secondly, using only EMB agar for subculturing may cause missing of colistin-resistant strains.
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Affiliation(s)
- Deniz Gazel
- Department of Medical Microbiology, Gaziantep University, Faculty of Medicine, Gaziantep, Turkey
| | - Müşerref Tatman Otkun
- Department of Medical Microbiology, Çanakkale Onsekiz Mart University, Faculty of Medicine, Çanakkale, Turkey
| | - Alper Akçalı
- Department of Medical Microbiology, Çanakkale Onsekiz Mart University, Faculty of Medicine, Çanakkale, Turkey
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23
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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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Lytic transglycosylase contributes to the survival of lipooligosaccharide-deficient, colistin-dependent Acinetobacter baumannii. Clin Microbiol Infect 2019; 25:1156.e1-1156.e7. [DOI: 10.1016/j.cmi.2019.02.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 01/02/2019] [Accepted: 02/05/2019] [Indexed: 12/11/2022]
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25
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Dissecting Colistin Resistance Mechanisms in Extensively Drug-Resistant Acinetobacter baumannii Clinical Isolates. mBio 2019; 10:mBio.01083-19. [PMID: 31311879 PMCID: PMC6635527 DOI: 10.1128/mbio.01083-19] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The discovery of antibiotics revolutionized modern medicine and enabled us to cure previously deadly bacterial infections. However, a progressive increase in antibiotic resistance rates is a major and global threat for our health care system. Colistin represents one of our last-resort antibiotics that is still active against most Gram-negative bacterial pathogens, but increasing resistance is reported worldwide, in particular due to the plasmid-encoded protein MCR-1 present in pathogens such as Escherichia coli and Klebsiella pneumoniae. Here, we showed that colistin resistance in A. baumannii, a top-priority pathogen causing deadly nosocomial infections, is mediated through different avenues that result in increased activity of homologous phosphoethanolamine (PetN) transferases. Considering that MCR-1 is also a PetN transferase, our findings indicate that PetN transferases might be the Achilles heel of superbugs and that direct targeting of them may have the potential to preserve the activity of polymyxin antibiotics. Nosocomial infections with Acinetobacter baumannii are a global problem in intensive care units with high mortality rates. Increasing resistance to first- and second-line antibiotics has forced the use of colistin as last-resort treatment, and increasing development of colistin resistance in A. baumannii has been reported. We evaluated the transcriptional regulator PmrA as potential drug target to restore colistin efficacy in A. baumannii. Deletion of pmrA restored colistin susceptibility in 10 of the 12 extensively drug-resistant A. baumannii clinical isolates studied, indicating the importance of PmrA in the drug resistance phenotype. However, two strains remained highly resistant, indicating that PmrA-mediated overexpression of the phosphoethanolamine (PetN) transferase PmrC is not the exclusive colistin resistance mechanism in A. baumannii. A detailed genetic characterization revealed a new colistin resistance mechanism mediated by genetic integration of the insertion element ISAbaI upstream of the PmrC homolog EptA (93% identity), leading to its overexpression. We found that eptA was ubiquitously present in clinical strains belonging to the international clone 2, and ISAbaI integration upstream of eptA was required to mediate the colistin-resistant phenotype. In addition, we found a duplicated ISAbaI-eptA cassette in one isolate, indicating that this colistin resistance determinant may be embedded in a mobile genetic element. Our data disprove PmrA as a drug target for adjuvant therapy but highlight the importance of PetN transferase-mediated colistin resistance in clinical strains. We suggest that direct targeting of the homologous PetN transferases PmrC/EptA may have the potential to overcome colistin resistance in A. baumannii.
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Brunati C, Thomsen TT, Gaspari E, Maffioli S, Sosio M, Jabes D, Løbner-Olesen A, Donadio S. Expanding the potential of NAI-107 for treating serious ESKAPE pathogens: synergistic combinations against Gram-negatives and bactericidal activity against non-dividing cells. J Antimicrob Chemother 2019; 73:414-424. [PMID: 29092042 PMCID: PMC5890740 DOI: 10.1093/jac/dkx395] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 09/27/2017] [Indexed: 11/12/2022] Open
Abstract
Objectives To characterize NAI-107 and related lantibiotics for their in vitro activity against Gram-negative pathogens, alone or in combination with polymyxin, and against non-dividing cells or biofilms of Staphylococcus aureus. NAI-107 was also evaluated for its propensity to select or induce self-resistance in Gram-positive bacteria. Methods We used MIC determinations and chequerboard experiments to establish the antibacterial activity of the examined compounds against target microorganisms. Time-kill assays were used to evaluate killing of exponential and stationary-phase cells. The effects on biofilms (growth inhibition and biofilm eradication) were evaluated using biofilm-coated pegs. The frequency of spontaneous resistant mutants was evaluated by either direct plating or by continuous sub-culturing at 0.5 × MIC levels, followed by population analysis profiles. Results The results showed that NAI-107 and its brominated variant are highly active against Neisseria gonorrhoeae and some other fastidious Gram-negative pathogens. Furthermore, all compounds strongly synergized with polymyxin against Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa, and showed bactericidal activity. Surprisingly, NAI-107 alone was bactericidal against non-dividing A. baumannii cells. Against S. aureus, NAI-107 and related lantibiotics showed strong bactericidal activity against dividing and non-dividing cells. Activity was also observed against S. aureus biofilms. As expected for a lipid II binder, no significant resistance to NAI-107 was observed by direct plating or serial passages. Conclusions Overall, the results of the current work, along with previously published results on the efficacy of NAI-107 in experimental models of infection, indicate that this lantibiotic represents a promising option in addressing the serious threat of antibiotic resistance.
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Affiliation(s)
- Cristina Brunati
- NAICONS Srl, Viale Ortles 22/4, 20139 Milano, Italy.,KtedoGen Srl, Viale Ortles 22/4, 20139 Milano, Italy
| | - Thomas T Thomsen
- Department of Biology, University of Copenhagen, Ole Maaløe's Vej 5, 2200 Copenhagen, Denmark
| | | | | | - Margherita Sosio
- NAICONS Srl, Viale Ortles 22/4, 20139 Milano, Italy.,KtedoGen Srl, Viale Ortles 22/4, 20139 Milano, Italy
| | | | - Anders Løbner-Olesen
- Department of Biology, University of Copenhagen, Ole Maaløe's Vej 5, 2200 Copenhagen, Denmark
| | - Stefano Donadio
- NAICONS Srl, Viale Ortles 22/4, 20139 Milano, Italy.,KtedoGen Srl, Viale Ortles 22/4, 20139 Milano, Italy
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27
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Cheng YS, Sun W, Xu M, Shen M, Khraiwesh M, Sciotti RJ, Zheng W. Repurposing Screen Identifies Unconventional Drugs With Activity Against Multidrug Resistant Acinetobacter baumannii. Front Cell Infect Microbiol 2019; 8:438. [PMID: 30662875 PMCID: PMC6328479 DOI: 10.3389/fcimb.2018.00438] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 12/10/2018] [Indexed: 12/28/2022] Open
Abstract
Antibiotic-resistant nosocomial infections are an emerging public health issue; carbapenem-resistant gram-negative bacteria such as Acinetobacter baumannii are among the pathogens against which new therapeutic agents are desperately needed. Drug repurposing has recently emerged as an alternative approach to rapidly identifying effective drugs and drug combinations to combat drug resistant bacteria. We performed a drug repurposing screen against a highly virulent, multidrug resistant, Acinetobacter baumannii strain AB5075. This strain, isolated from a patient, is resistant to 25 first-line antibiotics for gram-negative bacteria. A compound screen using a bacterial growth assay led to identification and confirmation of 43 active compounds. Among these confirmed compounds, seven are approved drugs or pharmacologically active compounds for non-antimicrobial indications. Three of these drugs, 5-fluorouracil, fluspirilene, and Bay 11-7082 resensitized strain AB5075 to azithromycin and colistin in a two-drug combination format. The approach using a drug repurposing screen with a pathogen sample isolated from a patient and a high throughput bacterial growth assay led to the successful identification of new drug combinations to overcome a multidrug resistant bacterial infection.
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Affiliation(s)
- Yu-Shan Cheng
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, United States
| | - Wei Sun
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, United States
| | - Miao Xu
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, United States
| | - Min Shen
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, United States
| | - Mozna Khraiwesh
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Richard J Sciotti
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Wei Zheng
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, United States
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28
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Dortet L, Potron A, Bonnin RA, Plesiat P, Naas T, Filloux A, Larrouy-Maumus G. Rapid detection of colistin resistance in Acinetobacter baumannii using MALDI-TOF-based lipidomics on intact bacteria. Sci Rep 2018; 8:16910. [PMID: 30442963 PMCID: PMC6237936 DOI: 10.1038/s41598-018-35041-y] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 10/30/2018] [Indexed: 12/13/2022] Open
Abstract
With the dissemination of extremely drug resistant bacteria, colistin is now considered as the last-resort therapy for the treatment of infection caused by Gram-negative bacilli (including carbapenemase producers). Unfortunately, the increase use of colistin has resulted in the emergence of resistance as well. In A. baumannii, colistin resistance is mostly caused by the addition of phosphoethanolamine to the lipid A through the action of a phosphoethanolamine transferase chromosomally-encoded by the pmrC gene, which is regulated by the two-component system PmrA/PmrB. In A. baumannii clinical isolate the main resistance mechanism to colistin involves mutations in pmrA, pmrB or pmrC genes leading to the overexpression of pmrC. Although, rapid detection of resistance is one of the key issues to improve the treatment of infected patient, detection of colistin resistance in A. baumannii still relies on MIC determination through microdilution, which is time-consuming (16-24 h). Here, we evaluated the performance of a recently described MALDI-TOF-based assay, the MALDIxin test, which allows the rapid detection of colistin resistance-related modifications to lipid A (i.e phosphoethanolamine addition). This test accurately detected all colistin-resistant A. baumannii isolates in less than 15 minutes, directly on intact bacteria with a very limited sample preparation prior MALDI-TOF analysis.
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Affiliation(s)
- Laurent Dortet
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, SW7 2AZ, UK.
- Department of Bacteriology- Hygiene, Bicêtre Hospital, Assistance Publique - Hôpitaux de Paris, Le Kremlin-Bicêtre, France.
- EA7361 "Structure, dynamic, function and expression of broad spectrum β-lactamases", Paris-Sud University, LabEx Lermit, Faculty of Medecine, Le Kremlin-Bicêtre, France.
- French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France.
| | - Anais Potron
- French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France
- Bacteriology unit, University hospital of Besançon, Besançon, France
| | - Rémy A Bonnin
- Department of Bacteriology- Hygiene, Bicêtre Hospital, Assistance Publique - Hôpitaux de Paris, Le Kremlin-Bicêtre, France
- EA7361 "Structure, dynamic, function and expression of broad spectrum β-lactamases", Paris-Sud University, LabEx Lermit, Faculty of Medecine, Le Kremlin-Bicêtre, France
- French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France
| | - Patrick Plesiat
- French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France
- Bacteriology unit, University hospital of Besançon, Besançon, France
| | - Thierry Naas
- Department of Bacteriology- Hygiene, Bicêtre Hospital, Assistance Publique - Hôpitaux de Paris, Le Kremlin-Bicêtre, France
- EA7361 "Structure, dynamic, function and expression of broad spectrum β-lactamases", Paris-Sud University, LabEx Lermit, Faculty of Medecine, Le Kremlin-Bicêtre, France
- French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France
| | - Alain Filloux
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Gerald Larrouy-Maumus
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, SW7 2AZ, UK.
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Carretero-Ledesma M, García-Quintanilla M, Martín-Peña R, Pulido MR, Pachón J, McConnell MJ. Phenotypic changes associated with Colistin resistance due to Lipopolysaccharide loss in Acinetobacter baumannii. Virulence 2018; 9:930-942. [PMID: 29638177 PMCID: PMC5955468 DOI: 10.1080/21505594.2018.1460187] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Acinetobacter baumannii can acquire resistance to colistin via complete loss of lipopolysaccharide (LPS) biosynthesis due to mutations in the lpxA, lpxC and lpxD genes. However, although colistin is increasingly being used for the treatment of multidrug resistant infections, very few A. baumannii clinical isolates develop colistin resistance through loss of LPS biosynthesis. This may suggest that LPS loss affects virulence traits that play a role in the transmission and pathogenesis of A. baumannii. In this study we characterize multiple virulence phenotypes of colistin resistant, LPS-deficient derivatives of the ATCC 19606 strain and five multidrug resistant clinical isolates and their colistin resistant, LPS-deficient derivatives. Our results indicate that LPS loss results in growth defects compared to the parental strain in vitro both in laboratory media and human serum (competition indices of 0.58 and 7.0 × 10−7, respectively) and reduced ability to grow and disseminate in vivo (competition index 6.7 × 10−8). Infection with the LPS-deficient strain resulted in lower serum levels of pro-inflammatory cytokines TNF-α and IL-6 compared to the parent strain, and was less virulent in a mouse model of disseminated sepsis. LPS loss also significantly affected biofilm production, surface motility, growth under iron limitation and susceptibility to multiple disinfectants used in the clinical setting. These results demonstrate that LPS loss has a significant effect on multiple virulence traits, and may provide insight into the low incidence of colistin resistant strains lacking LPS that have been reported in the clinical setting.
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Affiliation(s)
- Marta Carretero-Ledesma
- a Clinical Unit of Infectious Diseases, Clinical Microbiology and Preventive Medicine; Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC /University of Seville , Seville , Spain
| | - Meritxell García-Quintanilla
- a Clinical Unit of Infectious Diseases, Clinical Microbiology and Preventive Medicine; Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC /University of Seville , Seville , Spain
| | - Reyes Martín-Peña
- a Clinical Unit of Infectious Diseases, Clinical Microbiology and Preventive Medicine; Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC /University of Seville , Seville , Spain
| | - Marina R Pulido
- a Clinical Unit of Infectious Diseases, Clinical Microbiology and Preventive Medicine; Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC /University of Seville , Seville , Spain
| | - Jerónimo Pachón
- a Clinical Unit of Infectious Diseases, Clinical Microbiology and Preventive Medicine; Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC /University of Seville , Seville , Spain.,b Department of Medicine , University of Seville , Seville , Spain
| | - Michael J McConnell
- a Clinical Unit of Infectious Diseases, Clinical Microbiology and Preventive Medicine; Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC /University of Seville , Seville , Spain
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30
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Hong YK, Ko KS. Development of colistin dependence in non-baumannii Acinetobacter species. Int J Antimicrob Agents 2018; 52:742-743. [PMID: 30103004 DOI: 10.1016/j.ijantimicag.2018.08.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/26/2018] [Accepted: 08/04/2018] [Indexed: 11/19/2022]
Affiliation(s)
- Yoon-Kyoung Hong
- Department of Molecular Cell Biology and Samsung Medical Center, Sungkyunkwan University School of Medicine, 2066 Seobu-ro, Jangan-gu, Suwon 16419, South Korea
| | - Kwan Soo Ko
- Department of Molecular Cell Biology and Samsung Medical Center, Sungkyunkwan University School of Medicine, 2066 Seobu-ro, Jangan-gu, Suwon 16419, South Korea.
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31
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Lima WG, Alves MC, Cruz WS, Paiva MC. Chromosomally encoded and plasmid-mediated polymyxins resistance in Acinetobacter baumannii: a huge public health threat. Eur J Clin Microbiol Infect Dis 2018. [PMID: 29524060 DOI: 10.1007/s10096-018-3223-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Acinetobacter baumannii is an opportunistic pathogen associated with nosocomial and community infections of great clinical relevance. Its ability to rapidly develop resistance to antimicrobials, especially carbapenems, has re-boosted the prescription and use of polymyxins. However, the emergence of strains resistant to these antimicrobials is becoming a critical issue in several regions of the world because very few of currently available antibiotics are effective in these cases. This review summarizes the most up-to-date knowledge about chromosomally encoded and plasmid-mediated polymyxins resistance in A. baumannii. Different mechanisms are employed by A. baumannii to overcome the antibacterial effects of polymyxins. Modification of the outer membrane through phosphoethanolamine addition, loss of lipopolysaccharide, symmetric rupture, metabolic changes affecting osmoprotective amino acids, and overexpression of efflux pumps are involved in this process. Several genetic elements modulate these mechanisms, but only three of them have been described so far in A. baumannii clinical isolates such as mutations in pmrCAB, lpxACD, and lpsB. Elucidation of genotypic profiles and resistance mechanisms are necessary for control and fight against resistance to polymyxins in A. baumannii, thereby protecting this class for future treatment.
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Affiliation(s)
- William Gustavo Lima
- Laboratory of Medical Microbiology, Central-West Campus Dona Lindu, Federal University of São João del-Rei, Rua Sebastião Gonçalves Coelho, 400, Divinopolis, Minas Gerais, 35501-293, Brazil.
| | - Mara Cristina Alves
- Laboratory of Laboratorial Diagnostic and Clinical Microbiology, Central-West Campus Dona Lindu, Federal University of São João del-Rei, Divinopolis, MG, Brazil
| | - Waleska Stephanie Cruz
- Laboratory of Molecular and Celular Biology, Alto Paraopeba Campus, Federal University of São João del-Rei, Ouro Branco, MG, Brazil
| | - Magna Cristina Paiva
- Laboratory of Laboratorial Diagnostic and Clinical Microbiology, Central-West Campus Dona Lindu, Federal University of São João del-Rei, Divinopolis, MG, Brazil
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32
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Farshadzadeh Z, Taheri B, Rahimi S, Shoja S, Pourhajibagher M, Haghighi MA, Bahador A. Growth Rate and Biofilm Formation Ability of Clinical and Laboratory-Evolved Colistin-Resistant Strains of Acinetobacter baumannii. Front Microbiol 2018; 9:153. [PMID: 29483899 PMCID: PMC5816052 DOI: 10.3389/fmicb.2018.00153] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 01/23/2018] [Indexed: 12/29/2022] Open
Abstract
Two different mechanisms of resistance to colistin in Acinetobacter baumannii have been described. The first involves the total loss of lipopolysaccharide (LPS) due to mutations in the lpxACD operon, which is involved in the lipid A biosynthesis pathway. The second entails the addition of ethanolamine to the lipid A of the LPS resulting from mutations in the PmrAB two-component system. To evaluate the impact of colistin resistance-associated mutations on antimicrobial resistance and virulence properties, four pairs of clinical and laboratory-evolved colistin-susceptible/colistin-resistant (ColS/ColR) A. baumannii isolates were used. Antimicrobial susceptibility, surface motility, in vitro and in vivo biofilm-forming capacity, in vitro and in vivo expression levels of biofilm-associated genes, and in vitro growth rate were analyzed in these strains. Growth rate, in vitro and in vivo biofilm formation ability, as well as expression levels of biofilm-associated gene were reduced in ColR LPS-deficient isolate (the lpxD mutant) when compared with its ColS partner, whereas there were not such differences between LPS-modified isolates (the pmrB mutants) and their parental isolates. Mutation in lpxD was accompanied by a greater reduction in minimum inhibitory concentrations of azithromycin, vancomycin, and rifampin than mutation in pmrB. Besides, loss of LPS was associated with a significant reduction in surface motility without any change in expression of type IV pili. Collectively, colistin resistance through loss of LPS causes a more considerable cost in biological features such as growth rate, motility, and biofilm formation capacity relative to LPS modification. Therefore, ColR LPS-modified strains are more likely to spread and transmit from one patient to another in hospital settings, which results in more complex treatment and control.
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Affiliation(s)
- Zahra Farshadzadeh
- Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Behrouz Taheri
- Department of Medical Laboratory Sciences, School of Paramedicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Sara Rahimi
- Department of Microbiology, Faculty of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Saeed Shoja
- Infectious and Tropical Disease Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - Maryam Pourhajibagher
- Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.,Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad A Haghighi
- Department of Microbiology, Faculty of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Abbas Bahador
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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33
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Ko KS, Choi Y, Lee JY. Old drug, new findings: colistin resistance and dependence of Acinetobacter baumannii. PRECISION AND FUTURE MEDICINE 2017. [DOI: 10.23838/pfm.2017.00184] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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Transition of colistin dependence into colistin resistance in Acinetobacter baumannii. Sci Rep 2017; 7:14216. [PMID: 29079752 PMCID: PMC5660220 DOI: 10.1038/s41598-017-14609-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 10/10/2017] [Indexed: 12/05/2022] Open
Abstract
We recently demonstrated a high rate of colistin dependence in Acinetobacter baumannii isolates exposed to colistin in vitro. In the present study, we obtained a colistin-resistant (H08-391R) and colistin-dependent mutant (H08-391D) from a colistin-susceptible parental strain (H08-391). We found that the colistin-dependent mutant converted into a stable colistin-resistant mutant (H08-391D-R) in vitro after four serial passages without colistin. H08-391D and H08-391D-R were both found to harbor defective lipid A, as indicated by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry analysis. Additionally, both contained an ISAba1 insertion in lpxC, which encodes a lipid A biosynthetic enzyme. Further, membrane potential measurements using the fluorescent dye 3,3′-diethyloxacarbocyanine iodide (DiOC2[3]) showed that the membrane potential of H08-391D and H08-391D-R was significantly decreased as compared to that of the parental strain, H08-391. Moreover, these mutant strains exhibited increased susceptibilities to antibiotics other than colistin, which may be attributed to their outer membrane fragility. Such phenomena were identified in other A. baumannii strains (H06-855 and its derivatives). Taken together, our study reveals that the colistin-dependent phenotype is a transient phenotype that allows A. baumannii to survive under colistin pressure, and can transition to the extremely resistant phenotype, even in an antibiotic-free environment.
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35
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Qu Y, Xu J, Zhou H, Dong R, Kang M, Zhao J. Chitin Oligosaccharide (COS) Reduces Antibiotics Dose and Prevents Antibiotics-Caused Side Effects in Adolescent Idiopathic Scoliosis (AIS) Patients with Spinal Fusion Surgery. Mar Drugs 2017; 15:md15030070. [PMID: 28335413 PMCID: PMC5367027 DOI: 10.3390/md15030070] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 02/19/2017] [Accepted: 03/08/2017] [Indexed: 01/13/2023] Open
Abstract
Antibiotics are always considered for surgical site infection (SSI) in adolescent idiopathic scoliosis (AIS) surgery. However, the use of antibiotics often causes the antibiotic resistance of pathogens and side effects. Thus, it is necessary to explore natural products as drug candidates. Chitin Oligosaccharide (COS) has anti-inflammation and anti-bacteria functions. The effects of COS on surgical infection in AIS surgery were investigated. A total of 312 AIS patients were evenly and randomly assigned into control group (CG, each patient took one-gram alternative Azithromycin/Erythromycin/Cloxacillin/Aztreonam/Ceftazidime or combined daily), experiment group (EG, each patient took 20 mg COS and half-dose antibiotics daily), and placebo group (PG, each patient took 20 mg placebo and half-dose antibiotics daily). The average follow-up was one month, and infection severity and side effects were analyzed. The effects of COS on isolated pathogens were analyzed. SSI rates were 2%, 3% and 8% for spine wounds and 1%, 2% and 7% for iliac wound in CG, EG and PG (p < 0.05), respectively. COS reduces the side effects caused by antibiotics (p < 0.05). COS improved biochemical indexes and reduced the levels of interleukin (IL)-6 and tumor necrosis factor (TNF) alpha. COS reduced the antibiotics dose and antibiotics-caused side effects in AIS patients with spinal fusion surgery by improving antioxidant and anti-inflammatory activities. COS should be developed as potential adjuvant for antibiotics therapies.
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Affiliation(s)
- Yang Qu
- Department of Orthopedics, The Second Hospital of JiLin University, Changchun 130041, China.
| | - Jinyu Xu
- Department of Orthopedics, The Second Hospital of JiLin University, Changchun 130041, China.
| | - Haohan Zhou
- Department of Orthopedics, The Second Hospital of JiLin University, Changchun 130041, China.
| | - Rongpeng Dong
- Department of Orthopedics, The Second Hospital of JiLin University, Changchun 130041, China.
| | - Mingyang Kang
- Department of Orthopedics, The Second Hospital of JiLin University, Changchun 130041, China.
| | - Jianwu Zhao
- Department of Orthopedics, The Second Hospital of JiLin University, Changchun 130041, China.
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Lee CR, Lee JH, Park M, Park KS, Bae IK, Kim YB, Cha CJ, Jeong BC, Lee SH. Biology of Acinetobacter baumannii: Pathogenesis, Antibiotic Resistance Mechanisms, and Prospective Treatment Options. Front Cell Infect Microbiol 2017; 7:55. [PMID: 28348979 PMCID: PMC5346588 DOI: 10.3389/fcimb.2017.00055] [Citation(s) in RCA: 487] [Impact Index Per Article: 69.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 02/13/2017] [Indexed: 12/27/2022] Open
Abstract
Acinetobacter baumannii is undoubtedly one of the most successful pathogens responsible for hospital-acquired nosocomial infections in the modern healthcare system. Due to the prevalence of infections and outbreaks caused by multi-drug resistant A. baumannii, few antibiotics are effective for treating infections caused by this pathogen. To overcome this problem, knowledge of the pathogenesis and antibiotic resistance mechanisms of A. baumannii is important. In this review, we summarize current studies on the virulence factors that contribute to A. baumannii pathogenesis, including porins, capsular polysaccharides, lipopolysaccharides, phospholipases, outer membrane vesicles, metal acquisition systems, and protein secretion systems. Mechanisms of antibiotic resistance of this organism, including acquirement of β-lactamases, up-regulation of multidrug efflux pumps, modification of aminoglycosides, permeability defects, and alteration of target sites, are also discussed. Lastly, novel prospective treatment options for infections caused by multi-drug resistant A. baumannii are summarized.
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Affiliation(s)
- Chang-Ro Lee
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
| | - Jung Hun Lee
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
| | - Moonhee Park
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji UniversityYongin, South Korea; DNA Analysis Division, Seoul Institute, National Forensic ServiceSeoul, South Korea
| | - Kwang Seung Park
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
| | - Il Kwon Bae
- Department of Dental Hygiene, College of Health and Welfare, Silla University Busan, South Korea
| | - Young Bae Kim
- Biotechnology Program, North Shore Community College Danvers, MA, USA
| | - Chang-Jun Cha
- Department of Systems Biotechnology, College of Biotechnology and Natural Resources, Chung-Ang University Anseong, South Korea
| | - Byeong Chul Jeong
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
| | - Sang Hee Lee
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
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Diversity of polymyxin resistance mechanisms among Acinetobacter baumannii clinical isolates. Diagn Microbiol Infect Dis 2017; 87:37-44. [DOI: 10.1016/j.diagmicrobio.2016.10.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 09/26/2016] [Accepted: 10/03/2016] [Indexed: 02/01/2023]
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38
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Zhou P, Zhao J. Structure, inhibition, and regulation of essential lipid A enzymes. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:1424-1438. [PMID: 27940308 DOI: 10.1016/j.bbalip.2016.11.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/28/2016] [Accepted: 11/30/2016] [Indexed: 10/20/2022]
Abstract
The Raetz pathway of lipid A biosynthesis plays a vital role in the survival and fitness of Gram-negative bacteria. Research efforts in the past three decades have identified individual enzymes of the pathway and have provided a mechanistic understanding of the action and regulation of these enzymes at the molecular level. This article reviews the discovery, biochemical and structural characterization, and regulation of the essential lipid A enzymes, as well as continued efforts to develop novel antibiotics against Gram-negative pathogens by targeting lipid A biosynthesis. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop.
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Affiliation(s)
- Pei Zhou
- Department of Biochemistry, Duke University Medical Center, Research Drive, DUMC 3711, Durham, NC 27710, USA.
| | - Jinshi Zhao
- Department of Biochemistry, Duke University Medical Center, Research Drive, DUMC 3711, Durham, NC 27710, USA
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39
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Baron S, Hadjadj L, Rolain JM, Olaitan AO. Molecular mechanisms of polymyxin resistance: knowns and unknowns. Int J Antimicrob Agents 2016; 48:583-591. [PMID: 27524102 DOI: 10.1016/j.ijantimicag.2016.06.023] [Citation(s) in RCA: 283] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/14/2016] [Accepted: 06/23/2016] [Indexed: 12/19/2022]
Abstract
Colistin, also referred to as polymyxin E, is an effective antibiotic against most multidrug-resistant Gram-negative bacteria and is currently used as a last-line drug for treating severe bacterial infections. Colistin resistance has increased gradually for the last few years, and knowledge of its multifaceted mechanisms is expanding. This includes the newly discovered plasmid-mediated colistin resistance gene mcr-1, which has been detected in over 20 countries within 3 months of its first report. We previously reported all of the known mechanisms of polymyxin resistance in our first review in 2014, but an update seems necessary in 2016, considering the significant recent discoveries that have been made in this domain. This review provides an update about what is already known, what is new, and some unresolved questions with respect to colistin resistance.
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Affiliation(s)
- Sophie Baron
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France
| | - Linda Hadjadj
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France
| | - Jean-Marc Rolain
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France.
| | - Abiola Olumuyiwa Olaitan
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France.
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40
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Inhibition of LpxC Increases Antibiotic Susceptibility in Acinetobacter baumannii. Antimicrob Agents Chemother 2016; 60:5076-9. [PMID: 27270288 DOI: 10.1128/aac.00407-16] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 06/02/2016] [Indexed: 02/02/2023] Open
Abstract
LpxC inhibitors have generally shown poor in vitro activity against Acinetobacter baumannii We show that the LpxC inhibitor PF-5081090 inhibits lipid A biosynthesis, as determined by silver staining and measurements of endotoxin levels, and significantly increases cell permeability. The presence of PF-5081090 at 32 mg/liter increased susceptibility to rifampin, vancomycin, azithromycin, imipenem, and amikacin but had no effect on susceptibility to ciprofloxacin and tigecycline. Potentiating existing antibiotics with LpxC inhibitors may represent an alternative treatment strategy for multidrug-resistant A. baumannii.
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Andersson D, Hughes D, Kubicek-Sutherland J. Mechanisms and consequences of bacterial resistance to antimicrobial peptides. Drug Resist Updat 2016; 26:43-57. [DOI: 10.1016/j.drup.2016.04.002] [Citation(s) in RCA: 319] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 04/07/2016] [Accepted: 04/11/2016] [Indexed: 10/21/2022]
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42
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Hong YK, Lee JY, Wi YM, Ko KS. High rate of colistin dependence in Acinetobacter baumannii. J Antimicrob Chemother 2016; 71:2346-8. [PMID: 27076109 DOI: 10.1093/jac/dkw121] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Affiliation(s)
- Yoon-Kyoung Hong
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Ji-Young Lee
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Yu Mi Wi
- Division of Infectious Diseases, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, South Korea
| | - Kwan Soo Ko
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, South Korea
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