1
|
Kaya F, Tuğcugil E. Hyperpigmentation on head and neck caused by polymyxin B: A rare case. Niger J Clin Pract 2023; 26:1393-1395. [PMID: 37794556 DOI: 10.4103/njcp.njcp_185_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/06/2023]
Abstract
Polymyxin B was widely used to treat drug-resistant gram-negative bacteria and showed a better antibacterial effect. However, it is associated with some side effects. It should be remembered that polymyxin B may cause hyperpigmentation, albeit rare. This is a case report of a 68-year-old male patient who developed hyperpigmentation following treatment of a chest infection with polymyxin B. He was a known patient with chronic kidney diasease and chronic obstructive pulmonary disease followed up in the intensive care unit due to acute exacerbation of COPD. Later, polymyxin B treatment was started due to the development of pneumonia caused by the multidrug-resistant Acinetobacter baumannii. On the second day of polymyxin B treatment, hyperpigmentation developed in the face and neck region. The fact that the patient had chronic kidney disease possibly facilitated the development of skin hyperpigmentation due to the cumulative effect of polymyxin B. Hyperpigmentation which a rare side effect of polymyxin B may occur in those with underlying kidney disease.
Collapse
Affiliation(s)
- F Kaya
- Department of Anesthesiology and Critical Care, Ahi Evren Thoracic and Cardiovascular Surgery Training and Research Hospital, Health Sciences University Trabzon, Trabzon, Turkey
| | - E Tuğcugil
- Department of Anesthesiology and Critical Care, Karadeniz Technical University, Faculty of Medicine, Trabzon, Turkey
| |
Collapse
|
2
|
Villanueva JA, Crooks AL, Nagy TA, Quintana JLJ, Dalebroux ZD, Detweiler CS. Salmonella enterica Infections Are Disrupted by Two Small Molecules That Accumulate within Phagosomes and Differentially Damage Bacterial Inner Membranes. mBio 2022; 13:e0179022. [PMID: 36135367 PMCID: PMC9601186 DOI: 10.1128/mbio.01790-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 09/06/2022] [Indexed: 11/23/2022] Open
Abstract
Gram-negative bacteria have a robust cell envelope that excludes or expels many antimicrobial agents. However, during infection, host soluble innate immune factors permeabilize the bacterial outer membrane. We identified two small molecules that exploit outer membrane damage to access the bacterial cell. In standard microbiological media, neither compound inhibited bacterial growth nor permeabilized bacterial outer membranes. In contrast, at micromolar concentrations, JAV1 and JAV2 enabled the killing of an intracellular human pathogen, Salmonella enterica serovar Typhimurium. S. Typhimurium is a Gram-negative bacterium that resides within phagosomes of cells from the monocyte lineage. Under broth conditions that destabilized the lipopolysaccharide layer, JAV2 permeabilized the bacterial inner membrane and was rapidly bactericidal. In contrast, JAV1 activity was more subtle: JAV1 increased membrane fluidity, altered reduction potential, and required more time than JAV2 to disrupt the inner membrane barrier and kill bacteria. Both compounds interacted with glycerophospholipids from Escherichia coli total lipid extract-based liposomes. JAV1 preferentially interacted with cardiolipin and partially relied on cardiolipin production for activity, whereas JAV2 generally interacted with lipids and had modest affinity for phosphatidylglycerol. In mammalian cells, neither compound significantly altered mitochondrial membrane potential at concentrations that killed S. Typhimurium. Instead, JAV1 and JAV2 became trapped within acidic compartments, including macrophage phagosomes. Both compounds improved survival of S. Typhimurium-infected Galleria mellonella larvae. Together, these data demonstrate that JAV1 and JAV2 disrupt bacterial inner membranes by distinct mechanisms and highlight how small, lipophilic, amine-substituted molecules can exploit host soluble innate immunity to facilitate the killing of intravesicular pathogens. IMPORTANCE Innovative strategies for developing new antimicrobials are needed. Combining our knowledge of host-pathogen interactions and relevant drug characteristics has the potential to reveal new approaches to treating infection. We identified two compounds with antibacterial activity specific to infection and with limited host cell toxicity. These compounds appeared to exploit host innate immunity to access the bacterium and differentially damage the bacterial inner membrane. Further, both compounds accumulated within Salmonella-containing and other acidic vesicles, a process known as lysosomal trapping, which protects the host and harms the pathogen. The compounds also increased host survival in an insect infection model. This work highlights the ability of host innate immunity to enable small molecules to act as antibiotics and demonstrates the feasibility of antimicrobial targeting of the inner membrane. Additionally, this study features the potential use of lysosomal trapping to enhance the activities of compounds against intravesicular pathogens.
Collapse
Affiliation(s)
- Joseph A. Villanueva
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Amy L. Crooks
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Toni A. Nagy
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Joaquin L. J. Quintana
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Zachary D. Dalebroux
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Corrella S. Detweiler
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| |
Collapse
|
3
|
Synergistic Antimicrobial Effect of Colistin in Combination with Econazole against Multidrug-Resistant Acinetobacter baumannii and Its Persisters. Microbiol Spectr 2022; 10:e0093722. [PMID: 35467374 PMCID: PMC9241926 DOI: 10.1128/spectrum.00937-22] [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] [Indexed: 11/20/2022] Open
Abstract
Colistin is a last-line antibiotic which acts by causing membrane permeabilization in Gram-negative bacteria. However, its clinical value has been limited by its toxicity and the emergence of resistant organisms. In this study, we showed that econazole and colistin can act synergistically to produce a strong antimicrobial effect sufficient for eradication of starvation-induced tolerant and multidrug-resistant populations of Acinetobacter baumannii, a notorious pathogen causing recalcitrant infections, both in vitro and in mouse infection models. Investigation of the underlying mechanism showed that, while colistin disrupts the membrane structure, econazole causes the dissipation of proton motive force, eliciting a vicious cycle of membrane structural damages and disruption of membrane protein functions, and eventually cell death. This drug combination therefore achieves our goal of using a much smaller dosage of colistin to produce a much stronger antimicrobial effect to tackle the problems of toxicity and resistance associated with colistin usage. IMPORTANCE Findings described in this study constitute concrete evidence that it is possible to significantly enhance the antimicrobial activity of colistin by using an antifungal drug, econazole, as a colistin adjuvant. We showed that this drug combination can kill not only multidrug-resistant A. baumannii but also the tolerant subpopulation of such strains known as persisters, which may cause chronic and recurrent infections in clinical settings. The synergistic killing effect of the econazole and colistin combination was also observable in mouse infection models at a very low concentration, suggesting that such a drug combination has high potential to be used clinically. Findings in this study therefore have important implications for enhancing its clinical application potential as well as developing new approaches to enhance treatment effectiveness and reduce suffering in patients.
Collapse
|
4
|
Repurposing of Ciclopirox to Overcome the Limitations of Zidovudine (Azidothymidine) against Multidrug-Resistant Gram-Negative Bacteria. Pharmaceutics 2022; 14:pharmaceutics14030552. [PMID: 35335928 PMCID: PMC8950944 DOI: 10.3390/pharmaceutics14030552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/17/2022] [Accepted: 02/28/2022] [Indexed: 11/17/2022] Open
Abstract
Multidrug-resistant (MDR) Gram-negative bacteria are the top-priority pathogens to be eradicated. Drug repurposing (e.g., the use of non-antibiotics to treat bacterial infections) may be helpful to overcome the limitations of current antibiotics. Zidovudine (azidothymidine, AZT), a licensed oral antiviral agent, is a leading repurposed drug against MDR Gram-negative bacterial infections. However, the rapid emergence of bacterial resistance due to long-term exposure, overuse, or misuse limits its application, making it necessary to develop new alternatives. In this study, we investigated the efficacy of ciclopirox (CPX) as an alternative to AZT. The minimum inhibitory concentrations of AZT and CPX against MDR Gram-negative bacteria were determined; CPX appeared more active against β-lactamase-producing Escherichia coli, whereas AZT displayed no selectivity for any antibiotic-resistant strain. Motility assays revealed that β-lactamase-producing Escherichia coli strains were less motile in nature and more strongly affected by CPX than a parental strain. Resistance against CPX was not observed in E. coli even after 25 days of growth, whereas AZT resistance was observed in less than 2 days. Moreover, CPX effectively killed AZT-resistant strains with different resistance mechanisms. Our findings indicate that CPX may be utilized as an alternative or supplement to AZT-based medications to treat opportunistic Gram-negative bacterial infections.
Collapse
|
5
|
Cho H, Naskar A, Lee S, Kim S, Kim KS. A New Surface Charge Neutralizing Nano-Adjuvant to Potentiate Polymyxins in Killing Mcr-1 Mediated Drug-Resistant Escherichia coli. Pharmaceutics 2021; 13:250. [PMID: 33670388 PMCID: PMC7917812 DOI: 10.3390/pharmaceutics13020250] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/04/2021] [Accepted: 02/08/2021] [Indexed: 01/03/2023] Open
Abstract
Resistance to polymyxins when treating multidrug-resistant (MDR) Gram-negative bacterial infections limit therapeutic options. Here, we report the synthesis of a nickel (Ni) doped Zinc oxide (NZO) combined with black phosphorus (BP) (NZB) nanocomposite and its synergistic action with polymyxin B (PolB) against polymyxin-resistant Escherichia coli harboring mobilized colistin resistance (mcr-1) gene. NZB and PolB combination therapy expressed a specific and strong synergy against Mcr-1 expressing E. coli cells. The underlying mechanism of the synergy is the charge neutralization of the E. coli cell surface by NZB, resulting in a more feasible incorporation of PolB to E. coli. The synergistic concentration of NZB with PolB was proved biocompatible. Thus, the NZB is the first biocompatible nano-adjuvant to polymyxins against polymyxin-resistant E. coli cells, recognizing the physical status of bacteria instead of known adjuvants targeting cellular gene products. Therefore, NZB has the potential to revive polymyxins as leading last-resort antibiotics to combat polymyxin-resistant Gram-negative bacterial infections.
Collapse
Affiliation(s)
- Hyejin Cho
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan 46241, Korea; (H.C.); (A.N.); (S.L.)
| | - Atanu Naskar
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan 46241, Korea; (H.C.); (A.N.); (S.L.)
| | - Sohee Lee
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan 46241, Korea; (H.C.); (A.N.); (S.L.)
| | - Semi Kim
- Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea;
| | - Kwang-Sun Kim
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan 46241, Korea; (H.C.); (A.N.); (S.L.)
| |
Collapse
|
6
|
Abstract
RATIONALE Polymyxin B has been used to treat extensively drug-resistant gram-negative bacteria and shown a better antibacterial effect in the clinic at present. Meanwhile, polymyxin B is associated with several adverse effects. However, there is a lack of awareness that polymyxin B can cause rhabdomyolysis. In this study, we firstly report a case of polymyxin B-induced rhabdomyolysis during antiinfection therapy. PATIENT CONCERNS A 70-year-old woman suffering from rheumatic heart disease underwent aortic and mitral valve replacement at our institute. Subsequently, she developed bacteremia and pneumonia caused by extensively drug resistance-acinetobacter baumannii. Polymyxin B was administered for 5 days. During treatment, the patient complained of muscle pain and limb weakness, and her serum creatine phosphokinase and myoglobin levels rose. DIAGNOSIS The clinical symptoms and laboratory examination confirmed rhabdomyolysis, and polymyxin B-induced rhabdomyolysis was considered. INTERVENTION We ceased polymyxin B treatment and monitored the patient daily. OUTCOMES Serum creatine phosphokinase levels returned to normal, myoglobin levels decreased, and muscle pain was significantly alleviated after cessation of polymyxin B. We identified this as a case of polymyxin B-induced rhabdomyolysis. LESSONS Here, we report the first reported case of rhabdomyolysis induced by polymyxin B administration. The awareness of rare adverse reaction helps ensure the clinical safety of polymyxin B treatment.
Collapse
Affiliation(s)
- Ming Ni
- Department of Clinical Pharmacy, Henan Provincial People's Hospital
- Department of Clinical Pharmacy, Fuwai Central China Cardiovascular Hospital, Zhengzhou
| | - Xiangdong Meng
- Department of Cardiovascular Surgery, Shanghai General Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai
| | - Limin Wang
- Department of Cardiovascular Surgery, Shanghai General Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai
| | - Yanan Zhao
- Department of Clinical Pharmacy, Henan Provincial Chest Hospital, Zhengzhou, China
| | - Min Yu
- Department of Cardiovascular Surgery, Shanghai General Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai
| | - Sheng Shi
- Department of Cardiovascular Surgery, Shanghai General Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai
| |
Collapse
|
7
|
Yu L, Zhang J, Fu Y, Zhao Y, Wang Y, Zhao J, Guo Y, Li C, Zhang X. Synergetic Effects of Combined Treatment of Colistin With Meropenem or Amikacin on Carbapenem-Resistant Klebsiella pneumoniae in vitro. Front Cell Infect Microbiol 2019; 9:422. [PMID: 31921701 PMCID: PMC6916149 DOI: 10.3389/fcimb.2019.00422] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/28/2019] [Indexed: 11/13/2022] Open
Abstract
The purpose of this study was to investigate the synergistic and bactericidal effects of combinations of colistin with meropenem or amikacin in vitro and provide laboratory data needed for development of therapeutic strategies for the treatment of carbapenem-resistant Klebsiella pneumoniae (CRKP) infection. We found that minimum inhibitory concentration (MIC) of colistin, meropenem and amikacin were 2~32, 4~256, and 1~16384 μg/ml, respectively. The minimum bactericidal concentration of the antibiotics was either 1× or 2×MIC. Treatments of 6 CRKP isolates at 1 μg/ml colistin completely killed 2 of them and suppressed 4 others growth. 4 CRKP isolates at 16 μg/ml meropenem or amikacin completely killed and suppressed 2 others growth. 2 CRKP isolates showed synergic effects in all colistin combination and 3 CRKP isolates showed synergic effects in part of colistin combination. Our data suggest that colistin in combination with either meropenem or amikacin could be a valid therapeutic option against colistin-resistant CRKP isolates. Moreover, the combination of colistin-amikacin is less expensive to treat CRKP infections in Eastern Heilongjiang Province.
Collapse
Affiliation(s)
- Lan Yu
- Department of Microbiology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China.,Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Jisheng Zhang
- Department of Microbiology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China.,Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Yanjun Fu
- Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Yongxin Zhao
- Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Yong Wang
- Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Jing Zhao
- Department of Scientific Research Section, Jiamusi University School of Clinical Medicine, Jiamusi, China
| | - Yuhang Guo
- Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Chunjiang Li
- Department of Pathogenic Biology, Jiamusi University School of Basic Medicine, Jiamusi, China
| | - Xiaoli Zhang
- Department of Microbiology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China.,Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| |
Collapse
|
8
|
Conley ZC, Carlson-Banning KM, Carter AG, de la Cova A, Song Y, Zechiedrich L. Sugar and iron: Toward understanding the antibacterial effect of ciclopirox in Escherichia coli. PLoS One 2019; 14:e0210547. [PMID: 30633761 PMCID: PMC6329577 DOI: 10.1371/journal.pone.0210547] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/27/2018] [Indexed: 12/11/2022] Open
Abstract
New antibiotics are needed against antibiotic-resistant gram-negative bacteria. The repurposed antifungal drug, ciclopirox, equally blocks antibiotic-susceptible or multidrug-resistant Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae clinical isolates, indicating that it is not affected by existing resistance mechanisms. Toward understanding how ciclopirox blocks growth, we screened E. coli mutant strains and found that disruption of genes encoding products involved in galactose salvage, enterobacterial common antigen synthesis, and transport of the iron binding siderophore, enterobactin, lowered the minimum inhibitory concentration of ciclopirox needed to block growth of the mutant compared to the isogenic parent strain. We found that ciclopirox induced enterobactin production and that this effect is strongly affected by the deletion of the galactose salvage genes encoding UDP-galactose 4-epimerase, galE, or galactose-1-phosphate uridylyltransferase, galT. As disruption of ECA synthesis activates the regulation of capsular synthesis (Rcs) phosphorelay, which inhibits bacterial swarming and promotes biofilm development, we test whether ciclopirox prevents activation of the Rcs pathway. Sub-inhibitory concentrations of ciclopirox increased swarming of the E. coli laboratory K12 strain BW25113 but had widely varying effects on swarming or surface motility of clinical isolate E. coli, A. baumannii, and K. pneumoniae. There was no effect of ciclopirox on biofilm production, suggesting it does not target Rcs. Altogether, our data suggest ciclopirox-mediated alteration of lipopolysaccharides stimulates enterobactin production and affects bacterial swarming.
Collapse
Affiliation(s)
- Zachary C. Conley
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Kimberly M. Carlson-Banning
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Ashley G. Carter
- Department of Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Alejandro de la Cova
- Department of Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
- Center for Environmental and Human Toxicology, University of Florida College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Yongcheng Song
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Lynn Zechiedrich
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, United States of America
| |
Collapse
|
9
|
Lahiry S, Choudhury S, Mukherjee A, Bhunya PK, Bala M. Polymyxin B-Induced Diffuse Cutaneous Hyperpigmentation. J Clin Diagn Res 2017; 11:FD01-FD02. [PMID: 28384882 DOI: 10.7860/jcdr/2017/24278.9213] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 10/22/2016] [Indexed: 11/24/2022]
Abstract
Polymyxin B is a polypeptide-antibiotic, primarily used for resistant Gram-negative infections, first obtained from bacterium Bacillus polymyxa in the late 1940s. Antibiotic spectrum are restricted to mainly gram negative bacterias like Enterobacter, E. coli, Klebsiella, Salmonella, Pasteurella, Bordetella, Shigella; and particularly organisms like Pseudomonas aeruginosa and Acinetobacter baumannii, which are extremely potent to acquire antibiotic resistance. Side effects include neurotoxicity and acute renal tubular necrosis. Here, we present a rare case of skin hyper-pigmentation in a 65-year-old elderly male of Indian origin, diagnosed as a case of Multi-Drug Resistant (MDR) Klebsiella pneumonia, treated with intravenous antibiotics. The manifestations were observed after 4 days of Polymyxin B therapy initiation. All other concomitant drugs, infections, or immunologic disorders that, could have caused this symptom, were carefully excluded. An objective causality assessment reveals that, the cutaneous hyperpigmentation was possibly associated with Polymyxin B therapy, though further studies may be needed to explain the underlying mechanism.
Collapse
Affiliation(s)
- Sandeep Lahiry
- Post Graduate Trainee, Department of Pharmacology, Institute of Post Graduate Medical Education and Research , Kolkata, West Bengal, India
| | - Shouvik Choudhury
- Post Graduate Trainee, Department of Pharmacology, Institute of Post Graduate Medical Education and Research , Kolkata, West Bengal, India
| | - Ayan Mukherjee
- Post Graduate Trainee, Department of Pharmacology, Institute of Post Graduate Medical Education and Research , Kolkata, West Bengal, India
| | - Prajesh Kiran Bhunya
- Post Graduate Trainee, Department of Pharmacology, Institute of Post Graduate Medical Education and Research , Kolkata, West Bengal, India
| | - Moumita Bala
- Post Graduate Trainee, Department of Pharmacology, Institute of Post Graduate Medical Education and Research , Kolkata, West Bengal, India
| |
Collapse
|
10
|
Combination therapy with polymyxin B and netropsin against clinical isolates of multidrug-resistant Acinetobacter baumannii. Sci Rep 2016; 6:28168. [PMID: 27306928 PMCID: PMC4910107 DOI: 10.1038/srep28168] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 06/01/2016] [Indexed: 12/26/2022] Open
Abstract
Polymyxins are last-resort antibiotics for treating infections of Gram-negative bacteria. The recent emergence of polymyxin-resistant bacteria, however, urgently demands clinical optimisation of polymyxin use to minimise further evolution of resistance. In this study we developed a novel combination therapy using minimal concentrations of polymyxin B. After large-scale screening of Streptomyces secondary metabolites, we identified a reliable polymixin synergist and confirmed as netropsin using high-pressure liquid chromatography, nuclear magnetic resonance, and mass spectrometry followed by in vitro assays using various Gram-negative pathogenic bacteria. To evaluate the effectiveness of combining polymixin B and netropsin in vivo, we performed survival analysis on greater wax moth Galleria mellonella infected with colistin-resistant clinical Acinetobacter baumannii isolates as well as Escherichia coli, Shigella flexineri, Salmonella typhimuruim, and Pseudomonas aeruginosa. The survival of infected G. mellonella was significantly higher when treated with polymyxin B and netropsin in combination than when treated with polymyxin B or netropsin alone. We propose a netropsin combination therapy that minimises the use of polymyxin B when treating infections with multidrug resistant Gram-negative bacteria.
Collapse
|