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Sugawara-Mikami M, Tanigawa K, Kawashima A, Kiriya M, Nakamura Y, Fujiwara Y, Suzuki K. Pathogenicity and virulence of Mycobacterium leprae. Virulence 2022; 13:1985-2011. [PMID: 36326715 PMCID: PMC9635560 DOI: 10.1080/21505594.2022.2141987] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leprosy is caused by Mycobacterium leprae (M. leprae) and M. lepromatosis, an obligate intracellular organism, and over 200,000 new cases occur every year. M. leprae parasitizes histiocytes (skin macrophages) and Schwann cells in the peripheral nerves. Although leprosy can be treated by multidrug therapy, some patients relapse or have a prolonged clinical course and/or experience leprosy reaction. These varying outcomes depend on host factors such as immune responses against bacterial components that determine a range of symptoms. To understand these host responses, knowledge of the mechanisms by which M. leprae parasitizes host cells is important. This article describes the characteristics of leprosy through bacteriology, genetics, epidemiology, immunology, animal models, routes of infection, and clinical findings. It also discusses recent diagnostic methods, treatment, and measures according to the World Health Organization (WHO), including prevention. Recently, the antibacterial activities of anti-hyperlipidaemia agents against other pathogens, such as M. tuberculosis and Staphylococcus aureus have been investigated. Our laboratory has been focused on the metabolism of lipids which constitute the cell wall of M. leprae. Our findings may be useful for the development of future treatments.
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Affiliation(s)
- Mariko Sugawara-Mikami
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Tokyo, Japan.,West Yokohama Sugawara Dermatology Clinic, Yokohama, Japan
| | - Kazunari Tanigawa
- Department of Molecular Pharmaceutics, Faculty of Pharma-Science, Teikyo University, Tokyo, Japan
| | - Akira Kawashima
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Tokyo, Japan
| | - Mitsuo Kiriya
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Tokyo, Japan
| | - Yasuhiro Nakamura
- Department of Molecular Pharmaceutics, Faculty of Pharma-Science, Teikyo University, Tokyo, Japan
| | - Yoko Fujiwara
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Tokyo, Japan
| | - Koichi Suzuki
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Tokyo, Japan
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Ahuja M, Singh I, Lavania M, Pathak VK, Darlong J, Turankar RP, Hembrom S, Singh SV, Sengupta U. Ofloxacin resistance in multibacillary new leprosy cases from Purulia, West Bengal: A threat to effective secondary line treatment for rifampicin resistant leprosy cases. J Glob Antimicrob Resist 2022; 30:282-285. [PMID: 35717020 DOI: 10.1016/j.jgar.2022.06.008] [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: 12/02/2021] [Revised: 06/06/2022] [Accepted: 06/08/2022] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE Purulia is one of the high endemic districts for leprosy in West Bengal [Eastern part of India]. The annual new case detection rate (ANCDR) of leprosy in West Bengal is 6.04/100000 (DGHS 2019-20). Our earlier report has already provided the evidence of presence of secondary drug resistance in relapse cases of leprosy. The primary aim of the study was to find out primary drug resistance pattern for dapsone, rifampicin and ofloxacin among new leprosy patients from Purulia, West Bengal. to find out the emergence of primary drug resistance to any of these drugs. METHODS In the present study, slit- skin smear samples were collected from 145 newly diagnosed leprosy cases from TLM Purulia hospital during the duration between 2017-2018. DNA was extracted from these samples and were analyzed for the genes associated with drug resistance in M. leprae genome by PCR and was followed by Sanger sequencing. Wild-type strain (Thai-53) and mouse footpad-derived drug-resistant (Z-4) strain was used as reference strains. RESULTS Out of 145 cases; 25 cases had shown mutation in any of the three genes of rpoB, folP and gyrA associated with rifampicin, dapsone and ofloxacin resistance as described by WHO respectively by Sanger sequencing. Among these 25 cases; 16 cases had shown the mutations in ofloxacin, 2 cases had shown the mutation in combination of ofloxacin and rifampicin, 4 cases had shown the mutation only in rifampicin, 1 case had shown mutation in combination of rifampicin and dapsone and 2 cases had shown mutation only in dapsone. DISCUSSION AND CONCLUSION Results from this study indicated the emergence of resistance to anti-leprosy drugs in new cases of leprosy. As ofloxacin is the alternate drug for the treatment of rifampicin resistant cases, the emergence of new cases with resistance to ofloxacin indicates that ofloxacin resistant M. leprae strains are actively circulating in endemic region i. e. Purulia, West Bengal of India and poses a concern about the effective treatment of rifampicin resistance cases.
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Affiliation(s)
- Madhvi Ahuja
- Stanley Browne Laboratory, The Leprosy Mission Community Hospital, New Delhi, India; Department of Biotechnology, GLA University, Mathura, India
| | - Itu Singh
- Stanley Browne Laboratory, The Leprosy Mission Community Hospital, New Delhi, India
| | - Mallika Lavania
- Stanley Browne Laboratory, The Leprosy Mission Community Hospital, New Delhi, India; Enteric Viruses Group, Indian Council of Medical Research National Institute of Virology, Pune, India; Formerly at Stanley Browne Laboratory, The Leprosy Mission Community Hospital, New Delhi, India.
| | - Vinay Kumar Pathak
- Stanley Browne Laboratory, The Leprosy Mission Community Hospital, New Delhi, India
| | - Joydeepa Darlong
- Stanley Browne Laboratory, The Leprosy Mission Community Hospital, New Delhi, India; The Leprosy Mission Hospital, Purulia, India
| | - Ravindra P Turankar
- Stanley Browne Laboratory, The Leprosy Mission Community Hospital, New Delhi, India
| | - S Hembrom
- The Leprosy Mission Hospital, Purulia, India
| | | | - Utpal Sengupta
- Stanley Browne Laboratory, The Leprosy Mission Community Hospital, New Delhi, India
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Prasetyoputri A, Jarrad AM, Cooper MA, Blaskovich MA. The Eagle Effect and Antibiotic-Induced Persistence: Two Sides of the Same Coin? Trends Microbiol 2019; 27:339-354. [DOI: 10.1016/j.tim.2018.10.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/21/2018] [Accepted: 10/18/2018] [Indexed: 12/21/2022]
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Antonova AV, Gryadunov DA, Zimenkov DV. Molecular Mechanisms of Drug Tolerance in Mycobacterium tuberculosis. Mol Biol 2018. [DOI: 10.1134/s0026893318030020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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de Knegt GJ, van der Meijden A, de Vogel CP, Aarnoutse RE, de Steenwinkel JEM. Activity of moxifloxacin and linezolid against Mycobacterium tuberculosis in combination with potentiator drugs verapamil, timcodar, colistin and SQ109. Int J Antimicrob Agents 2017; 49:302-307. [PMID: 28162983 DOI: 10.1016/j.ijantimicag.2016.11.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 11/03/2016] [Accepted: 11/25/2016] [Indexed: 01/17/2023]
Abstract
Current treatment for tuberculosis (TB) is complicated by the emergence of multidrug resistant TB (MDR-TB). As a result, there is an urgent need for new powerful anti-TB regimens and novel strategies. In this study, we aimed to potentiate a moxifloxacin + linezolid backbone as treatment for MDR-TB with the efflux pump inhibitors verapamil and timcodar as well as with drugs that act on mycobacterial cell wall stability such as colistin and SQ109. Using a time-kill kinetics assay, the activities of moxifloxacin, linezolid, verapamil, timcodar, colistin and SQ109 as single drugs against Mycobacterium tuberculosis were evaluated. In addition, the activity of the moxifloxacin + linezolid backbone in combination with one of the potentiator drugs was assessed. As little as 0.125 mg/L moxifloxacin achieved 99% killing of M. tuberculosis after 6 days of exposure. Linezolid showed moderate killing but 99% killing was not achieved. Verapamil, timcodar and colistin only resulted in killing with the highest concentrations tested but 99% killing was not achieved. SQ109 resulted in complete elimination after 1 day of exposure to 256 mg/L and in 99% elimination after 6 days of exposure to 1 mg/L. Furthermore, colistin added to the moxifloxacin + linezolid backbone resulted in increased elimination, whereas verapamil, timcodar and SQ109 showed no added value to the backbone. This finding that colistin potentiates the activity of the moxifloxacin + linezolid backbone against M. tuberculosis suggests its potential role in further studies on the applicability of a moxifloxacin + linezolid treatment of MDR-TB.
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Affiliation(s)
- Gerjo J de Knegt
- Department of Medical Microbiology & Infectious Diseases, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands.
| | - Aart van der Meijden
- Department of Medical Microbiology & Infectious Diseases, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Corné P de Vogel
- Department of Medical Microbiology & Infectious Diseases, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Rob E Aarnoutse
- Department of Pharmacy, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Jurriaan E M de Steenwinkel
- Department of Medical Microbiology & Infectious Diseases, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands
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Eagle Effect in Nonreplicating Persister Mycobacteria. Antimicrob Agents Chemother 2015; 59:7786-9. [PMID: 26349831 PMCID: PMC4649170 DOI: 10.1128/aac.01476-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 09/03/2015] [Indexed: 11/25/2022] Open
Abstract
We determined the microbicidal activities of antibacterials against nonreplicating Mycobacterium smegmatis grown in a starvation-based Loebel model for persistence. Whereas most drugs lost their activity, fluoroquinolones retained lethal potency. Dose-response characterizations showed a paradoxical more-drug-kills-less Eagle effect. Pretreatment of cultures with chloramphenicol blocked the lethal action of the gyrase inhibitors. These results suggest that fluoroquinolones at low concentrations trigger a protein synthesis-dependent cell death pathway and shut off this suicide pathway at elevated concentrations.
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Dartois V, Barry CE. A medicinal chemists' guide to the unique difficulties of lead optimization for tuberculosis. Bioorg Med Chem Lett 2013; 23:4741-50. [PMID: 23910985 PMCID: PMC3789655 DOI: 10.1016/j.bmcl.2013.07.006] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 06/27/2013] [Accepted: 07/03/2013] [Indexed: 10/26/2022]
Abstract
Tuberculosis is a bacterial disease that predominantly affects the lungs and results in extensive tissue pathology. This pathology contributes to the complexity of drug development as it presents discrete microenvironments within which the bacterium resides, often under conditions where replication is limited and intrinsic drug susceptibility is low. This consolidated pathology also results in impaired vascularization that limits access of potential lead molecules to the site of infection. Translating these considerations into a target-product profile to guide lead optimization programs involves implementing unique in vitro and in vivo assays to maximize the likelihood of developing clinically meaningful candidates.
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Affiliation(s)
- Véronique Dartois
- Public Health Research Institute, New Jersey Medical School, Newark, NJ, United States
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Malik M, Zhao X, Drlica K. Lethal fragmentation of bacterial chromosomes mediated by DNA gyrase and quinolones. Mol Microbiol 2006; 61:810-25. [PMID: 16803589 DOI: 10.1111/j.1365-2958.2006.05275.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
When DNA gyrase is trapped on bacterial chromosomes by quinolone antibacterials, reversible complexes form that contain DNA ends constrained by protein. Two subsequent processes lead to rapid cell death. One requires ongoing protein synthesis; the other does not. The prototype quinolone, nalidixic acid, kills wild-type Escherichia coli only by the first pathway; fluoroquinolones kill by both. Both lethal processes correlated with irreversible chromosome fragmentation, detected by sedimentation and viscosity of DNA from quinolone-treated cells. However, only fluoroquinolones fragmented purified nucleoids when incubated with gyrase purified from wild-type cells. A GyrA amino acid substitution (A67S) expected to perturb a GyrA-GyrA dimer interface allowed nalidixic acid to fragment chromosomes and kill cells in the absence of protein synthesis; moreover, it made a non-inducible lexA mutant hypersusceptible to nalidixic acid, a property restricted to fluoroquinolones with wild-type cells. The GyrA variation also facilitated immunoprecipitation of DNA fragments by GyrA antiserum following nalidixic acid treatment of cells. The ability of changes in both gyrase and quinolone structure to enhance protein synthesis-independent lethality and chromosome fragmentation is explained by drug-mediated destabilization of gyrase-DNA complexes. Instability of type II topoisomerase-DNA complexes may be a general phenomenon that can be exploited to kill cells.
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Affiliation(s)
- Muhammad Malik
- Public Health Research Institute, 225 Warren Street, Newark, NJ 07103, USA
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Scollard DM, Adams LB, Gillis TP, Krahenbuhl JL, Truman RW, Williams DL. The continuing challenges of leprosy. Clin Microbiol Rev 2006; 19:338-81. [PMID: 16614253 PMCID: PMC1471987 DOI: 10.1128/cmr.19.2.338-381.2006] [Citation(s) in RCA: 498] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Leprosy is best understood as two conjoined diseases. The first is a chronic mycobacterial infection that elicits an extraordinary range of cellular immune responses in humans. The second is a peripheral neuropathy that is initiated by the infection and the accompanying immunological events. The infection is curable but not preventable, and leprosy remains a major global health problem, especially in the developing world, publicity to the contrary notwithstanding. Mycobacterium leprae remains noncultivable, and for over a century leprosy has presented major challenges in the fields of microbiology, pathology, immunology, and genetics; it continues to do so today. This review focuses on recent advances in our understanding of M. leprae and the host response to it, especially concerning molecular identification of M. leprae, knowledge of its genome, transcriptome, and proteome, its mechanisms of microbial resistance, and recognition of strains by variable-number tandem repeat analysis. Advances in experimental models include studies in gene knockout mice and the development of molecular techniques to explore the armadillo model. In clinical studies, notable progress has been made concerning the immunology and immunopathology of leprosy, the genetics of human resistance, mechanisms of nerve injury, and chemotherapy. In nearly all of these areas, however, leprosy remains poorly understood compared to other major bacterial diseases.
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Affiliation(s)
- D M Scollard
- Laboratory Research Branch, National Hansen's Disease Programs, LSU-SVM, Skip Bertman Dr., Baton Rouge, LA 70803, USA.
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Ankö ML, Kurittu J, Karp M. An Escherichia coli biosensor strain for amplified and high throughput detection of antimicrobial agents. JOURNAL OF BIOMOLECULAR SCREENING 2002; 7:119-25. [PMID: 12006110 DOI: 10.1177/108705710200700204] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We report here the construction of a bacterial reporter system for high-throughput screening of antimicrobial agents. The test organism is the Escherichia coli K-12 strain carrying luciferase genes luxC, luxD, luxA, luxB, and luxE from the bioluminescent bacterium Photorhabdus luminescens in a runaway replication plasmid. The replication of the plasmid can be induced, resulting in a change of the plasmid copy number from 1-2/cell to several hundreds per cell within tens of minutes. This increase in plasmid copies is independent of the replication of the host cells. The system will therefore amplify the effects of antibiotics inhibiting bacterial replication machinery, such as fluoroquinolones, and the inhibitory effects can be measured in real time by luminometry. The biosensor was compared with a strain engineered to emit light constitutively, and it was shown to be much more sensitive to various antibiotics than conventional overnight cultivation methods. The approach shows great potential for high-throughput screening of new compounds.
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Abstract
Tuberculosis (TB) remains one of the main causes of morbidity worldwide, and the emergence of multi-drug resistant (MDR) Mycobacterium tuberculosis strains in some parts of the world has become a major concern. The decrease in activity of the major anti-TB drugs, such as isoniazid and rifampicin, is an important threat and alternative therapies are urgently required. The anti-TB activity of the fluoroquinolones has been under investigation since the 1980s. Many are active in vitro but only a few, including ofloxacin, ciprofloxacin, sparfloxacin, levofloxacin and lomefloxacin, have been clinically tested. Fluoroquinolones can be used in co-therapy with the available anti-TB drugs. However, the choice of fluoroquinolone should be based not only on the in vitro activity, but also on the long-term tolerance. Fluoroquinolones are novel anti-TB drugs to be used when a patient is infected with a MDR-TB strain.
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Affiliation(s)
- André Bryskier
- Aventis Pharma SA, Infectious Disease Group, Clinical Pharmacology, 102, route de Noisy, 93235 Romainville, Cédex, France.
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Verma I, Rohilla A, Khuller GK. Alterations in macromolecular composition and cell wall integrity by ciprofloxacin in Mycobacterium smegmatis. Lett Appl Microbiol 1999; 29:113-7. [PMID: 10499299 DOI: 10.1046/j.1365-2672.1999.00597.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The present study has been undertaken to explore the biochemical mechanism of antimycobacterial action of a potent fluoroquinolone i.e. ciprofloxacin in Mycobacterium smegmatis. Cells grown in the presence of a subinhibitory concentration (IC50) of ciprofloxacin had a significantly lower content of all the major macromolecules i.e. DNA, RNA, proteins and lipids with maximum inhibition in DNA concentration as compared to control. Significant quantitative changes were also observed in the various chemical constituents of cell wall of ciprofloxacin grown cells. A decrease in the number of binding sites for a fluorescent probe L-anilinonapthalene-8-sulphonate (ANS) in ciprofloxacin grown cells suggested structural changes on the cell surface. Significant changes were also observed in the morphology of cells grown in the presence of ciprofloxacin by scanning electron microscopy (SEM). Our results suggest that ciprofloxacin exerts its antimycobacterial activity by affecting the cell wall as well as various macromolecules, particular DNA, the vital component for cell survival and growth.
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Affiliation(s)
- I Verma
- Dept. of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Zhao BY, Pine R, Domagala J, Drlica K. Fluoroquinolone action against clinical isolates of Mycobacterium tuberculosis: effects of a C-8 methoxyl group on survival in liquid media and in human macrophages. Antimicrob Agents Chemother 1999; 43:661-6. [PMID: 10049284 PMCID: PMC89177 DOI: 10.1128/aac.43.3.661] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
When the lethal action of a C-8 methoxyl fluoroquinolone against clinical isolates of Mycobacterium tuberculosis in liquid medium was measured, the compound was found to be three to four times more effective (as determined by measuring the 90% lethal dose) than a C-8-H control fluoroquinolone or ciprofloxacin against cells having a wild-type gyrA (gyrase) gene. Against ciprofloxacin-resistant strains, the C-8 methoxyl group enhanced lethality when alanine was replaced by valine at position 90 of the GyrA protein or when aspartic acid 94 was replaced by glycine, histidine, or tyrosine. During infection of a human macrophage model by wild-type Mycobacterium bovis BCG, the C-8 methoxyl group lowered survival 20- to 100-fold compared with the same concentration of a C-8-H fluoroquinolone. The C-8 methoxyl fluoroquinolone was also more effective than ciprofloxacin against a gyrA Asn94 mutant of M. bovis BCG. In an M. tuberculosis-macrophage system the C-8 methoxyl group improved fluoroquinolone action against both quinolone-susceptible and quinolone-resistant clinical isolates. Thus, a C-8 methoxyl group enhances the bactericidal activity of quinolones with N1-cyclopropyl substitutions; these data encourage further refinement of fluoroquinolones as antituberculosis agents.
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Affiliation(s)
- B Y Zhao
- Public Health Research Institute, New York, New York 10016, USA
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Dong Y, Xu C, Zhao X, Domagala J, Drlica K. Fluoroquinolone action against mycobacteria: effects of C-8 substituents on growth, survival, and resistance. Antimicrob Agents Chemother 1998; 42:2978-84. [PMID: 9797236 PMCID: PMC105976 DOI: 10.1128/aac.42.11.2978] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fluoroquinolones trap gyrase on DNA as bacteriostatic complexes from which lethal DNA breaks are released. Substituents at the C-8 position increase activities of N-1-cyclopropyl fluoroquinolones against several bacterial species. In the present study, a C-8-methoxyl group improved bacteriostatic action against gyrA (gyrase-resistant) strains of Mycobacterium tuberculosis and M. bovis BCG. It also enhanced lethal action against gyrase mutants of M. bovis BCG. When cultures of M. smegmatis, M. bovis BCG, and M. tuberculosis were challenged with a C-8-methoxyl fluoroquinolone, no resistant mutant was recovered under conditions in which more than 1, 000 mutants were obtained with a C-8-H control. A C-8-bromo substituent also increased bacteriostatic and lethal activities against a gyrA mutant of M. bovis BCG. When lethal activity was normalized to bacteriostatic activity, the C-8-methoxyl compound was more bactericidal than its C-8-H control, while the C-8-bromo fluoroquinolone was not. The C-8-methoxyl compound was also found to be more effective than the C-8-bromo fluoroquinolone at reducing selection of resistant mutants when each was compared to a C-8-H control over a broad concentration range. These data indicate that a C-8-methoxyl substituent, which facilitates attack of first-step gyrase mutants, may help make fluoroquinolones effective antituberculosis agents.
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Affiliation(s)
- Y Dong
- Public Health Research Institute, New York, New York 10016, USA
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Peloquin CA, Berning SE, Huitt GA, Iseman MD. Levofloxacin for drug-resistant Mycobacterium tuberculosis. Ann Pharmacother 1998; 32:268-9. [PMID: 9496417 DOI: 10.1345/aph.17167] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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Abstract
For many years, DNA gyrase was thought to be responsible both for unlinking replicated daughter chromosomes and for controlling negative superhelical tension in bacterial DNA. However, in 1990 a homolog of gyrase, topoisomerase IV, that had a potent decatenating activity was discovered. It is now clear that topoisomerase IV, rather than gyrase, is responsible for decatenation of interlinked chromosomes. Moreover, topoisomerase IV is a target of the 4-quinolones, antibacterial agents that had previously been thought to target only gyrase. The key event in quinolone action is reversible trapping of gyrase-DNA and topoisomerase IV-DNA complexes. Complex formation with gyrase is followed by a rapid, reversible inhibition of DNA synthesis, cessation of growth, and induction of the SOS response. At higher drug concentrations, cell death occurs as double-strand DNA breaks are released from trapped gyrase and/or topoisomerase IV complexes. Repair of quinolone-induced DNA damage occurs largely via recombination pathways. In many gram-negative bacteria, resistance to moderate levels of quinolone arises from mutation of the gyrase A protein and resistance to high levels of quinolone arises from mutation of a second gyrase and/or topoisomerase IV site. For some gram-positive bacteria, the situation is reversed: primary resistance occurs through changes in topoisomerase IV while gyrase changes give additional resistance. Gyrase is also trapped on DNA by lethal gene products of certain large, low-copy-number plasmids. Thus, quinolone-topoisomerase biology is providing a model for understanding aspects of host-parasite interactions and providing ways to investigate manipulation of the bacterial chromosome by topoisomerases.
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Affiliation(s)
- K Drlica
- Public Health Research Institute, New York, New York 10016, USA.
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Renau TE, Gage JW, Dever JA, Roland GE, Joannides ET, Shapiro MA, Sanchez JP, Gracheck SJ, Domagala JM, Jacobs MR, Reynolds RC. Structure-activity relationships of quinolone agents against mycobacteria: effect of structural modifications at the 8 position. Antimicrob Agents Chemother 1996; 40:2363-8. [PMID: 8891145 PMCID: PMC163535 DOI: 10.1128/aac.40.10.2363] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
A series of quinolones with substitutions at the 8 position has been prepared as part of a study to examine the relationship between structural modifications at this position and activity against mycobacteria. The compounds were prepared by procedures described in the literature and were evaluated for their activities against Mycobacterium fortuitum and Mycobacterium smegmatis. The activities of the compounds against these two organisms were used as a measure of Mycobacterium tuberculosis activity. The results demonstrate that the contribution of the 8 position to antimycobacterial activity was dependent on the substituent at N-1 and was in the order (i) COMe approximately CBr > CCI > CH approximately CF approximately COEt > N > CCF3 when N-1 was cyclopropyl; (ii) N approximately CH > CF > COMe when N-1 was 2,4-difluorophenyl; (iii) N > or = CH when N-1 was tert-butyl; and (iv) N > CH when N-1 was ethyl. In general, derivatives with piperazine substitutions at C-7 were slightly less active against mycobacteria than the analogs with pyrrolidine substitutions, regardless of the pattern of substitution at the 8 position. Several of the best compounds were evaluated for their potential side effects as well as their activities against Mycobacterium aurum, Mycobacterium avium-M. intracellulare, and M. tuberculosis. These agents exhibited biological profiles similar to or better than those of the positive controls ciprofloxacin and sparfloxacin.
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Affiliation(s)
- T E Renau
- Parke-Davis Pharmaceutical Research, Division of Warner-Lambert Company, Ann Arbor, Michigan 48105, USA
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