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de Souza MQ, Bierhals DV, Reis AJ, Chimara E, Vianna JS, von Groll A, da Silva PA, Ramis IB. 2,3,5-triphenyl tetrazolium chloride as colorimetric indicator for drug susceptibility testing against nontuberculous mycobacteria. Diagn Microbiol Infect Dis 2024; 108:116096. [PMID: 37931387 DOI: 10.1016/j.diagmicrobio.2023.116096] [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: 04/05/2023] [Revised: 09/04/2023] [Accepted: 09/22/2023] [Indexed: 11/08/2023]
Abstract
This study aimed to propose and evaluate a drug susceptibility testing (DST) using the 2,3,5-triphenyl tetrazolium chloride (TTC) as a colorimetric indicator against Mycobacterium abscessus complex (MABC), M. avium complex (MAC), and M. kansasii strains, main nontuberculous mycobacteria (NTM) of clinical relevance. Our results demonstrated that the assay using TTC and the broth microdilution method recommended by the Clinical and Laboratory Standards Institute had essential agreement above 91%, 92%, and 100%, for drugs tested against MABC, MAC, and M. kansasii strains, respectively. Categorical agreement above 91% was obtained for most drugs tested against MABC, except to cefoxitin (76.5%). For drugs tested against MAC and M. kansasii, categorical agreement above 92% and 100% was observed, respectively. TTC showed to be a promising colorimetric indicator of growth to be used in DST for NTM, allowing an easier reading of results.
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Affiliation(s)
- Mariana Quaresma de Souza
- Laboratório de Micobactérias, Núcleo de Pesquisa em Microbiologia Médica, Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Medicina, Universidade Federal do Rio Grande, Rio Grande, Rio Grande do Sul, Brazil
| | - Dienefer Venske Bierhals
- Laboratório de Micobactérias, Núcleo de Pesquisa em Microbiologia Médica, Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Medicina, Universidade Federal do Rio Grande, Rio Grande, Rio Grande do Sul, Brazil
| | - Ana Julia Reis
- Laboratório de Micobactérias, Núcleo de Pesquisa em Microbiologia Médica, Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Medicina, Universidade Federal do Rio Grande, Rio Grande, Rio Grande do Sul, Brazil
| | - Erica Chimara
- Núcleo de Tuberculose e Micobacterioses, Instituto Adolfo Lutz, São Paulo, Brazil
| | - Júlia Silveira Vianna
- Laboratório de Micobactérias, Núcleo de Pesquisa em Microbiologia Médica, Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Medicina, Universidade Federal do Rio Grande, Rio Grande, Rio Grande do Sul, Brazil
| | - Andrea von Groll
- Laboratório de Micobactérias, Núcleo de Pesquisa em Microbiologia Médica, Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Medicina, Universidade Federal do Rio Grande, Rio Grande, Rio Grande do Sul, Brazil
| | - Pedro Almeida da Silva
- Laboratório de Micobactérias, Núcleo de Pesquisa em Microbiologia Médica, Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Medicina, Universidade Federal do Rio Grande, Rio Grande, Rio Grande do Sul, Brazil.
| | - Ivy Bastos Ramis
- Laboratório de Micobactérias, Núcleo de Pesquisa em Microbiologia Médica, Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Medicina, Universidade Federal do Rio Grande, Rio Grande, Rio Grande do Sul, Brazil
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Yue C, Wang L, Wang X, Cen R, Chen J, Li L, Yang W, Tan Y, Lei X. In vitro study of the effect of ALA-PDT on Mycobacterium abscessus and its antibiotic susceptibility. Photodiagnosis Photodyn Ther 2022; 38:102802. [PMID: 35297368 DOI: 10.1016/j.pdpdt.2022.102802] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 02/24/2022] [Accepted: 03/10/2022] [Indexed: 11/16/2022]
Abstract
BACKGROUND The skin infection caused by Mycobacterium abscessus (M. abscessus) is extremely difficult to treat in clinical practice. PDT (photodynamic therapy) is a promising antibacterial treatment. We evaluated the effect of photodynamic therapy using 5-aminolevulinic acid (ALA) as a photosensitizer on M. abscessus and its antibiotic resistance in this study. METHODS M. abscessus and biofilm were treated with different concentrations of ALA and then irradiated with LED light (635 nm, 80 J/cm2), while there were ALA-only group, light-only group, and negative control group. The effects were observed by colony counting, crystal violet staining, confocal laser scanning microscope (CLSM), and scanning electron microscope (SEM). The changes of drug susceptibility of M. abscessus at sublethal doses were detected by micro-broth dilution method, and the possible mechanism was explored by fluorometer and real-time fluorescence quantitative Polymerase Chain Reaction (RT-qPCR). RESULTS ALA-PDT showed a significant killing effect on M. abscessus at ALA concentrations greater than 50 μg/ml and the effect increased with increasing photosensitizer concentrations. ALA-PDT also showed a notable scavenging effect on M. abscessus biofilm, which was also enhanced with increasing ALA concentrations. At sublethal doses, the susceptibility of M. abscessus to antibiotics was increased, and ALA-PDT greatly increased the cell wall permeability of M. abscessus and decreased the mRNA expression of drug resistance genes whiB7 and erm (41), as well as efflux pump genes MAB_1409c and MAB_3142c at the transcriptional level. CONCLUSIONS ALA-PDT has a significant killing effect on M. abscessus and can increase its antibiotic susceptibility.
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Affiliation(s)
- Chenda Yue
- Department of Dermatology, Daping Hospital, The Army Medical University, Chongqing, China
| | - Liqun Wang
- Department of Dermatology, Daping Hospital, The Army Medical University, Chongqing, China
| | - Xiaoyu Wang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering Institute of Chongqing University, Chongqing, China
| | - Ruiyan Cen
- Department of Dermatology, Daping Hospital, The Army Medical University, Chongqing, China
| | - Jinyi Chen
- Department of Dermatology, Daping Hospital, The Army Medical University, Chongqing, China
| | - Lingfei Li
- Department of Dermatology, Daping Hospital, The Army Medical University, Chongqing, China
| | - Weijiang Yang
- Department of Dermatology, Daping Hospital, The Army Medical University, Chongqing, China
| | - Yang Tan
- Department of Dermatology, Daping Hospital, The Army Medical University, Chongqing, China
| | - Xia Lei
- Department of Dermatology, Daping Hospital, The Army Medical University, Chongqing, China.
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Hanh BTB, Park JW, Kim TH, Kim JS, Yang CS, Jang K, Cui J, Oh DC, Jang J. Rifamycin O, An Alternative Anti- Mycobacterium abscessus Agent. Molecules 2020; 25:molecules25071597. [PMID: 32244387 PMCID: PMC7181020 DOI: 10.3390/molecules25071597] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/26/2020] [Accepted: 03/30/2020] [Indexed: 02/07/2023] Open
Abstract
Mycobacterium abscessus is the most difficult-to-treat nontuberculous mycobacteria because of its resistance to many antibiotics. In this study, we screened the Korea Chemical Bank library for a bioluminescent reporter assay to identify molecules capable of acting against M. abscessus. On application of the assay, rifamycin O showed excellent in vitro activity with a narrow range of the minimum inhibitory concentration required to inhibit the growth of 90% of the bacterium (MIC90 = 4.0-6.2 μM); its in vivo efficacy in the zebrafish (Danio rerio) infection model was comparable to that of rifabutin at 25 μM. Furthermore, rifamycin O did not show significant toxicity in cells and the zebrafish model. These results are the first in vivo indication that rifamycin O may be a drug candidate for treating M. abscessus infections.
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Affiliation(s)
- Bui Thi Bich Hanh
- Molecular Mechanisms of Antibiotics, Division of Life Science, Research Institute of Life Science, Gyeongsang National University, Jinju 52828, Korea; (B.T.B.H.); (T.H.K.)
- Division of Applied Life Science (BK21plus Program), Gyeongsang National University, Jinju 52828, Korea
| | - June-Woo Park
- Environmental Biology Research Group, Korea Institute of Toxicology, Jinju 52834, Korea;
- Human and Environmental Toxicology Program, Korea University of Science and Technology (UST), Daejeon 34113, Korea
| | - Tae Ho Kim
- Molecular Mechanisms of Antibiotics, Division of Life Science, Research Institute of Life Science, Gyeongsang National University, Jinju 52828, Korea; (B.T.B.H.); (T.H.K.)
- Division of Applied Life Science (BK21plus Program), Gyeongsang National University, Jinju 52828, Korea
| | - Jae-Sung Kim
- Department of Bionano Technology, Hanyang University, Seoul 04763, Korea; (J.-S.K.); (C.-S.Y.)
- Department of Molecular & Life Science, Hanyang University, Ansan 15588, Korea
| | - Chul-Su Yang
- Department of Bionano Technology, Hanyang University, Seoul 04763, Korea; (J.-S.K.); (C.-S.Y.)
- Department of Molecular & Life Science, Hanyang University, Ansan 15588, Korea
| | - Kiseok Jang
- Department of Pathology, Hanyang University College of Medicine, Seoul 04763, Korea;
| | - Jinsheng Cui
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Korea; (J.C.); (D.-C.O.)
| | - Dong-Chan Oh
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Korea; (J.C.); (D.-C.O.)
| | - Jichan Jang
- Molecular Mechanisms of Antibiotics, Division of Life Science, Research Institute of Life Science, Gyeongsang National University, Jinju 52828, Korea; (B.T.B.H.); (T.H.K.)
- Division of Applied Life Science (BK21plus Program), Gyeongsang National University, Jinju 52828, Korea
- Correspondence: ; Tel.: +82-(0)55-772-1368
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Rakhmawatie MD, Wibawa T, Lisdiyanti P, Pratiwi WR, Mustofa. Evaluation of crystal violet decolorization assay and resazurin microplate assay for antimycobacterial screening. Heliyon 2019; 5:e02263. [PMID: 31497667 PMCID: PMC6722264 DOI: 10.1016/j.heliyon.2019.e02263] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/28/2019] [Accepted: 08/06/2019] [Indexed: 11/29/2022] Open
Abstract
The main obstacle in antimycobacterial discovery is the extremely slow growth rates of pathogenic mycobacteria that lead to the long incubation times needed in antimycobacterial screening. Some in vitro testings has been developed and are currently available for antimycobacterial screening. The aim of the study was to compare Resazurin Microplate Assay (REMA) and Crystal Violet Decolorization Assay (CVDA) for testing mycobacteria susceptibility to isoniazid and rifampicin as well as for antimycobacterial screening of natural products (NP). Mycobacterium tuberculosis strain H37Rv and Mycobacterium smegmatis strain mc2 155 were used as tested mycobacteria. Serial two-fold dilutions from 0.0625 to 1.0 μg/mL for the isoniazid and rifampicin and from 6.25 to 100.0 μg/mL for the NP A and B were prepared. Tested mycobacteria were then incubated with tested drugs or NPs in each growth medium at 37 °C for 7 days for M. tuberculosis and 3 days for M. smegmatis. MIC values against M. tuberculosis were interpreted 24-48 h after adding resazurin or at least 72 h after adding crystal violet, whereas MIC values against M. smegmatis were interpreted 1 h after adding resazurin or 24 h after adding crystal violet. The MIC values against M. tuberculosis interpreted by REMA were 0.0625, 0.0625, 6.25, and >100 μg/mL for rifampicin, isoniazid, NP A, and NP B, respectively, and those interpreted by CVDA were 0.0625, 0.0625, 6.25, and >100 μg/mL for rifampicin, isoniazid, NP A, and NP B, respectively. Moreover, the MIC values against M. smegmatis interpreted by REMA were 0.0625, >1, 6.25, and 100 μg/mL for rifampicin, isoniazid, NP A, and NP B, respectively, and those interpreted by CVDA were 0.125, >1, 6.25, and >100 μg/mL for rifampicin, isoniazid, NP A, NP B respectively. In conclusion, REMA is faster and easier than CVDA to interpret MIC values, however CVDA produces higher MIC values than REMA for rifampicin and NP B in M. smegmatis susceptibility testing. Therefore, REMA and CVDA can be used for antimycobacterial screening.
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Affiliation(s)
- Maya Dian Rakhmawatie
- Doctoral Program in Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
- Department of Biomedical Sciences, Faculty of Medicine, Universitas Muhammadiyah Semarang, Semarang, Indonesia
| | - Tri Wibawa
- Department of Microbiology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Puspita Lisdiyanti
- Research Center for Biotechnology, Indonesian Institute of Sciences, Bogor, Indonesia
| | - Woro Rukmi Pratiwi
- Department of Pharmacology and Therapy, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Mustofa
- Department of Pharmacology and Therapy, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
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Ramis IB, Vianna JS, Silva Junior L, von Groll A, Ramos DF, Lobo MM, Zanatta N, Viveiros M, Silva PEAD. In silico and in vitro evaluation of tetrahydropyridine compounds as efflux inhibitors in Mycobacterium abscessus. Tuberculosis (Edinb) 2019; 118:101853. [PMID: 31430699 DOI: 10.1016/j.tube.2019.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 07/18/2019] [Accepted: 07/22/2019] [Indexed: 12/23/2022]
Abstract
Herein, we evaluated tetrahydropyridine (THP) compounds (NUNM) as antimicrobials and inhibitors of the efflux mechanism in M. abscessus. subsp. abscessus. The modulation factor (MF) of efflux inhibitors was calculated from the minimum inhibitory concentrations (MICs) of amikacin (AMI), ciprofloxacin (CIP) and clarithromycin (CLA) in the absence and presence of subinhibitory concentrations of the NUNM compounds and canonical inhibitors carbonyl cyanide m-chlorophenyl hydrazone (CCCP) and verapamil (VP). The kinetics of the intracellular accumulation of the fluorimetric substrate ethidium bromide (EtBr) was evaluated and calculated by the relative final fluorescence (RFF). In addition, molecular modeling simulations for the MmpL5 and Tap efflux transporters with ligands (CLA, NUNM, CCCP, VP and EtBr) were performed to better understand the efflux mechanism. We highlight the NUNM01 compound because it reduced the MICs of AMI, CIP and CLA by 4-, 4- and 16-fold, respectively, had the highest effect on EtBr accumulation (RFF = 3.1) and showed a significant in silico affinity for the evaluated proteins in docking simulations. Based on the analyses performed in vitro and in silico, we propose that NUNM01 is a potential pharmacophore candidate for the development of a therapeutic adjuvant for M. abscessus infections.
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Affiliation(s)
- Ivy B Ramis
- Núcleo de Pesquisa Em Microbiologia Médica, Universidade Federal de Rio Grande, Rua General Osório s/n, Rio Grande, RS, Brazil
| | - Júlia S Vianna
- Núcleo de Pesquisa Em Microbiologia Médica, Universidade Federal de Rio Grande, Rua General Osório s/n, Rio Grande, RS, Brazil.
| | - Lande Silva Junior
- Núcleo de Pesquisa Em Microbiologia Médica, Universidade Federal de Rio Grande, Rua General Osório s/n, Rio Grande, RS, Brazil; Instituto Federal Sul-rio-grandense, Pelotas, RS, Brazil
| | - Andrea von Groll
- Núcleo de Pesquisa Em Microbiologia Médica, Universidade Federal de Rio Grande, Rua General Osório s/n, Rio Grande, RS, Brazil
| | - Daniela F Ramos
- Núcleo de Pesquisa Em Microbiologia Médica, Universidade Federal de Rio Grande, Rua General Osório s/n, Rio Grande, RS, Brazil
| | - Marcio Marçal Lobo
- Núcleo de Química de Heterociclos, Departamento de Química, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - Nilo Zanatta
- Núcleo de Química de Heterociclos, Departamento de Química, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - Miguel Viveiros
- Unidade de Microbiologia Médica, Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade NOVA de Lisboa, UNL, Lisboa, Portugal
| | - Pedro E Almeida da Silva
- Núcleo de Pesquisa Em Microbiologia Médica, Universidade Federal de Rio Grande, Rua General Osório s/n, Rio Grande, RS, Brazil
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Tetrahydropyridine derivative as efflux inhibitor in Mycobacterium abscessus. J Glob Antimicrob Resist 2019; 17:296-299. [PMID: 30630106 DOI: 10.1016/j.jgar.2018.12.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 12/30/2018] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVES This study aimed to evaluate a tetrahydropyridine derivative (THP) as a potential inhibitor of the efflux mechanism and modulator of the high level of antimicrobial resistance usually observed in members of the Mycobacterium abscessus (M. abscessus) group. METHODS The strain M. abscessus subsp. abscessus (ATCC 19997) was used as reference, in addition to three clinical isolates: M. abscessus subsp. abscessus (AT 07), and two M. abscessus subsp. bolletii (AT 46 and AT 52). The minimum inhibitory concentration (MIC) of amikacin (AMI), ciprofloxacin (CIP), clarithromycin (CLA), verapamil (VP), and THP derivative (NUNL02) was determined. RESULTS The NUNL02 showed activity against M. abscessus; the MIC of AMI against ATCC 19997 was reduced more than 16-fold, and the MIC of CIP against AT 52 was reduced four-fold. When combined with CLA, the MIC was reduced against all tested strains. In addition, to detect and quantify the activity of the efflux mechanism, the intracellular accumulation kinetics of the fluorometric substrate ethidium bromide in the presence and absence of VP and NUNL02 were evaluated. The NUNL02 was found to be a more effective efflux inhibitor than VP, which is the classical inhibitor. CONCLUSIONS The tetrahydropyridine derivative, NUNL02, is a promising adjuvant in the treatment of infections caused by M. abscessus.
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Leonard H, Halachmi S, Ben-Dov N, Nativ O, Segal E. Unraveling Antimicrobial Susceptibility of Bacterial Networks on Micropillar Architectures Using Intrinsic Phase-Shift Spectroscopy. ACS NANO 2017; 11:6167-6177. [PMID: 28485961 DOI: 10.1021/acsnano.7b02217] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
With global antimicrobial resistance becoming increasingly detrimental to society, improving current clinical antimicrobial susceptibility testing (AST) is crucial to allow physicians to initiate appropriate antibiotic treatment as early as possible, reducing not only mortality rates but also the emergence of resistant pathogens. In this work, we tackle the main bottlenecks in clinical AST by designing biofunctionalized silicon micropillar arrays to provide both a preferable solid-liquid interface for bacteria networking and a simultaneous transducing element that monitors the response of bacteria when exposed to chosen antibiotics in real time. We harness the intrinsic ability of the micropillar architectures to relay optical phase-shift reflectometric interference spectroscopic measurements (referred to as PRISM) and employ it as a platform for culture-free, label-free phenotypic AST. The responses of E. coli to various concentrations of five clinically relevant antibiotics are optically tracked by PRISM, allowing for the minimum inhibitory concentration (MIC) values to be determined and compared to both standard broth microdilution testing and clinic-based automated AST system readouts. Capture of bacteria within these microtopologies, followed by incubation of the cells with the appropriate antibiotic solution, yields rapid determinations of antibiotic susceptibility. This platform not only provides accurate MIC determinations in a rapid manner (total assay time of 2-3 h versus 8 h with automated AST systems) but can also be employed as an advantageous method to differentiate bacteriostatic and bactericidal antibiotics.
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Affiliation(s)
- Heidi Leonard
- Department of Biotechnology and Food Engineering, ‡Department of Urology, Bnai Zion Medical Center, Faculty of Medicine, and §The Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology , Haifa 3200003, Israel
| | - Sarel Halachmi
- Department of Biotechnology and Food Engineering, ‡Department of Urology, Bnai Zion Medical Center, Faculty of Medicine, and §The Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology , Haifa 3200003, Israel
| | - Nadav Ben-Dov
- Department of Biotechnology and Food Engineering, ‡Department of Urology, Bnai Zion Medical Center, Faculty of Medicine, and §The Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology , Haifa 3200003, Israel
| | - Ofer Nativ
- Department of Biotechnology and Food Engineering, ‡Department of Urology, Bnai Zion Medical Center, Faculty of Medicine, and §The Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology , Haifa 3200003, Israel
| | - Ester Segal
- Department of Biotechnology and Food Engineering, ‡Department of Urology, Bnai Zion Medical Center, Faculty of Medicine, and §The Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology , Haifa 3200003, Israel
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Xu L, Qian L, Kang J, Sha S, Xin Y, Lu S, Ma Y. Down-regulation of N-acetylglucosamine-1-phosphate transferase (WecA) enhanced the sensitivity of Mycobacterium smegmatis against rifampin. J Appl Microbiol 2016; 121:966-72. [PMID: 27420559 DOI: 10.1111/jam.13228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 05/25/2016] [Accepted: 07/04/2016] [Indexed: 11/30/2022]
Abstract
AIMS To construct a conditional N-acetylglucosamine-1-phosphate transferase (WecA) knockdown strain of Mycobacterium smegmatis and to investigate the biological effect of WecA on mycobacterial growth, morphology and susceptibilities against anti-tuberculosis drugs. METHODS AND RESULTS Mycobacterium smegmatis wecA knockdown strain was constructed by using a tetracycline-inducible expression vector pMind and the expression of WecA was regulated by antisense RNA. The results of growth curves and the colony formation unit curves showed that the growth rate of WecA down-regulation strain was decreased and the amount of live bacterial cells dropped. In addition, the wecA knockdown strain exhibited dramatically morphological alterations through scanning electron microscopy observation. The susceptibility of WecA low-expression strain to anti-tuberculosis drugs was detected by using a rapid resazurin microtitre assay as well as a traditional agar dilution method. Notably, the wecA knockdown strain was more sensitive to rifampin, compared with the wecA normal-expression strain. In addition, the sensitivity of wild type Myco. smegmatis mc(2) 155 strain against rifampin was also enhanced in the presence of a low concentration of tunicamycin, a natural WecA inhibitor. CONCLUSIONS Down-regulation of WecA enhanced the sensitivity of Myco. smegmatis against rifampin. SIGNIFICANCE AND IMPACT OF THE STUDY These results provided a possibility of combined application of rifampin together with tunicamycin or other WecA inhibitors, which could be a new approach for the treatment of tuberculosis.
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Affiliation(s)
- L Xu
- Scientific Research Center, The Second Affiliated Hospital of Dalian Medical University, Dalian, China.,Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China
| | - L Qian
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China
| | - J Kang
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China
| | - S Sha
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China
| | - Y Xin
- Department of Biotechnology, Dalian Medical University, Dalian, China.,Liaoning Provincial Core Lab of Glycobiology and Glycoengineering, Dalian, China
| | - S Lu
- Scientific Research Center, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Y Ma
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China. .,Liaoning Provincial Core Lab of Glycobiology and Glycoengineering, Dalian, China.
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Garcia de Carvalho NF, Sato DN, Pavan FR, Ferrazoli L, Chimara E. Resazurin Microtiter Assay for Clarithromycin Susceptibility Testing of Clinical Isolates of Mycobacterium abscessus Group. J Clin Lab Anal 2016; 30:751-5. [PMID: 27169515 DOI: 10.1002/jcla.21933] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 12/09/2015] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Mycobacterium abscessus group has heterogeneous susceptibility pattern among species. The species is most common cause of nosocomial infections. Macrolides minimum Inhibitory concentration (MIC) determination is essential for the treatment. METHODS Thirty-six strains were randomly selected for performing Resazurin Microtiter Assay (REMA) for clarithromycin testing in comparison to MIC test according to Clinical and Laboratory Standards Institute (2011) recommendation. REMA has been used for detection of drug resistance in M. tuberculosis. Extended incubation was performed to detect induced resistance. RESULTS Thirty microliters of resazurin (0.01%) was added after visually taking MIC reading. Resistance was observed in 11.1% of M. bolletti and 4.8% of M. abscessus strains; and induced resistance was detected in 77.8% and 95.2% of M. bolletti and M. abscessus strains, respectively. All strains of M. massiliense were susceptible. The samples presented same MIC value both by visual reading and through resazurin. CONCLUSION The present study showed 100% concordance between both readings, with REMA providing easier to read and report results benefit. This change in reading can also reflect on the MIC determination and report, improving the test.
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Affiliation(s)
| | - Daisy Nakamura Sato
- Nucleo de Tuberculose e Micobacterioses, Instituto Adolfo Lutz, Sao Paulo, Brazil
| | - Fernando R Pavan
- Laboratório de Micobacteriologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista "Júlio de Mesquita Filho,", Araraquara, Brazil
| | - Lucilaine Ferrazoli
- Nucleo de Tuberculose e Micobacterioses, Instituto Adolfo Lutz, Sao Paulo, Brazil
| | - Erica Chimara
- Nucleo de Tuberculose e Micobacterioses, Instituto Adolfo Lutz, Sao Paulo, Brazil.
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