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Liu X, He B, Zhang J, Yuan C, Han S, Du G, Shi J, Sun J, Zhang B. Phytosterol conversion into C9 non-hydroxylated derivatives through gene regulation in Mycobacterium fortuitum. Appl Microbiol Biotechnol 2023; 107:7635-7646. [PMID: 37831185 DOI: 10.1007/s00253-023-12812-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 08/23/2023] [Accepted: 09/22/2023] [Indexed: 10/14/2023]
Abstract
Androst-4-ene-3,17-dione (AD) and 22-hydroxy-23,24-bisnorchol-4-ene-3-one (4-HBC) are important drug intermediates that can be biosynthesized from phytosterols. However, the C9 hydroxylation of steroids via 3-ketosteroid 9α-hydroxylase (KSH) limits AD and 4-HBC accumulation. Five active KshAs, the oxidation component of KSH, were identified in Mycobacterium fortuitum ATCC 35855 for the first time. The deletion of kshAs indicated that the five KshA genes were jointly responsible for C9 hydroxylation during phytosterol biotransformation. MFKDΔkshA, the five KshAs deficient strain, blocked C9 hydroxylation and produced 5.37 g/L AD and 0.55 g/L 4-HBC. The dual function reductase Opccr knockout and 17β-hydroxysteroid dehydrogenase Hsd4A enhancement reduced 4-HBC content from 8.75 to 1.72% and increased AD content from 84.13 to 91.34%, with 8.24 g/L AD being accumulated from 15 g/L phytosterol. In contrast, hsd4A and thioesterase fadA5 knockout resulted in the accumulation of 5.36 g/L 4-HBC from 10 g/L phytosterol. We constructed efficient AD (MFKDΔkshAΔopccr_hsd4A) and 4-HBC (MFKDΔkshAΔhsd4AΔfadA5) producers and provided insights for further metabolic engineering of the M. fortuitum ATCC 35855 strain for steroid productions. KEY POINTS: • Five active KshAs were first identified in M. fortuitum ATCC 35855. • Deactivation of all five KshAs blocks the steroid C9 hydroxylation reaction. • AD or 4-HBC production was improved by Hsd4A, FadA5, and Opccr modification.
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Affiliation(s)
- Xiangcen Liu
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Beiru He
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Jingxian Zhang
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, China
| | - Chenyang Yuan
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Suwan Han
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Guilin Du
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Jiping Shi
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, China
| | - Junsong Sun
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Baoguo Zhang
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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Sharma A, Bansal S, Kumari N, Vashistt J, Shrivastava R. Comparative proteomic investigation unravels the pathobiology of Mycobacterium fortuitum biofilm. Appl Microbiol Biotechnol 2023; 107:6029-6046. [PMID: 37542577 DOI: 10.1007/s00253-023-12705-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 06/26/2023] [Accepted: 07/15/2023] [Indexed: 08/07/2023]
Abstract
Biofilm formation by Mycobacterium fortuitum causes serious threats to human health due to its increased contribution to nosocomial infections. In this study, the first comprehensive global proteome analysis of M. fortuitum was reported under planktonic and biofilm growth states. A label-free Q Exactive Quadrupole-Orbitrap tandem mass spectrometry analysis was performed on the protein lysates. The differentially abundant proteins were functionally characterized and re-annotated using Blast2GO and CELLO2GO. Comparative analysis of the proteins among two growth states provided insights into the phenotypic switch, and fundamental pathways associated with pathobiology of M. fortuitum biofilm, such as lipid biosynthesis and quorum-sensing. Interaction network generated by the STRING database revealed associations between proteins that endure M. fortuitum during biofilm growth state. Hypothetical proteins were also studied to determine their functional alliance with the biofilm phenotype. CARD, VFDB, and PATRIC analysis further showed that the proteins upregulated in M. fortuitum biofilm exhibited antibiotic resistance, pathogenesis, and virulence. Heatmap and correlation analysis provided the biomarkers associated with the planktonic and biofilm growth of M. fortuitum. Proteome data was validated by qPCR analysis. Overall, the study provides insights into previously unexplored biochemical pathways that can be targeted by novel inhibitors, either for shortened treatment duration or for eliminating biofilm of M. fortuitum and related nontuberculous mycobacterial pathogens. KEY POINTS: • Proteomic analyses of M. fortuitum reveals novel biofilm markers. • Acetyl-CoA acetyltransferase acts as the phenotype transition switch. • The study offers drug targets to combat M. fortuitum biofilm infections.
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Affiliation(s)
- Ayushi Sharma
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, 173234, H.P, India
| | - Saurabh Bansal
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, 173234, H.P, India
| | - Neha Kumari
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, 173234, H.P, India
| | - Jitendraa Vashistt
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, 173234, H.P, India
| | - Rahul Shrivastava
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, 173234, H.P, India.
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Datta D, Khatri P, Banerjee C, Singh A, Meena R, Saha DR, Raman R, Rajamani P, Mitra A, Mazumder S. Calcium and Superoxide-Mediated Pathways Converge to Induce Nitric Oxide-Dependent Apoptosis in Mycobacterium fortuitum-Infected Fish Macrophages. PLoS One 2016; 11:e0146554. [PMID: 26752289 PMCID: PMC4713470 DOI: 10.1371/journal.pone.0146554] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 12/19/2015] [Indexed: 12/31/2022] Open
Abstract
Mycobacterium fortuitum causes ‘mycobacteriosis’ in wide range of hosts although the mechanisms remain largely unknown. Here we demonstrate the role of calcium (Ca+2)-signalling cascade on M. fortuitum-induced apoptosis in headkidney macrophages (HKM) of Clarias sp. M. fortuitum could trigger intracellular-Ca+2 influx leading to the activation of calmodulin (CaM), protein kinase C alpha (PKCα) and Calmodulin kinase II gamma (CaMKIIg). Gene silencing and inhibitor studies established the role of CaM in M. fortuitum pathogenesis. We noted that CaMKIIg activation is regulated by CaM as well as PKCα-dependent superoxide anions. This is altogether first report of oxidised CaMKIIg in mycobacterial infections. Our studies with targeted-siRNA and pharmacological inhibitors implicate CaMKIIg to be pro-apoptotic and critical for the activation of extra-cellular signal regulated kinase 1/2 (ERK1/2). Inhibiting the ERK1/2 pathway attenuated nitric oxide synthase 2 (NOS2)-induced nitric oxide (NO) production. Conversely, inhibiting the NOS2-NO axis by specific-siRNA and inhibitors down-regulated ERK1/2 activation suggesting the crosstalk between ERK1/2 and NO is essential for pathogenesis induced by the bacterium. Silencing the NOS2-NO axis enhanced intracellular bacterial survival and attenuated caspase-8 mediated activation of caspase-3 in the infected HKM. Our findings unveil hitherto unknown mechanism of M. fortuitum pathogenesis. We propose that M. fortuitum triggers intracellular Ca+2 elevations resulting in CaM activation and PKCα-mediated superoxide generation. The cascade converges in common pathway mediated by CaMKIIg resulting in the activation of ERK1/2-NOS2 axis. The crosstalk between ERK1/2 and NO shifts the balance in favour of caspase dependent apoptosis of M. fortuitum-infected HKM.
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Affiliation(s)
- Debika Datta
- Immunobiology Laboratory, Department of Zoology, University of Delhi, Delhi, India
| | - Preeti Khatri
- Immunobiology Laboratory, Department of Zoology, University of Delhi, Delhi, India
| | - Chaitali Banerjee
- Immunobiology Laboratory, Department of Zoology, University of Delhi, Delhi, India
| | - Ambika Singh
- Gut Biology Laboratory, Department of Zoology, University of Delhi, Delhi, India
| | - Ramavatar Meena
- School of Environmental Sciences, Jawaharlal Nehru University, Delhi, India
| | - Dhira Rani Saha
- Microscopy Laboratory, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Rajagopal Raman
- Gut Biology Laboratory, Department of Zoology, University of Delhi, Delhi, India
| | - Paulraj Rajamani
- School of Environmental Sciences, Jawaharlal Nehru University, Delhi, India
| | - Abhijit Mitra
- Genome Analysis Laboratory, Animal Division, Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Shibnath Mazumder
- Immunobiology Laboratory, Department of Zoology, University of Delhi, Delhi, India
- * E-mail:
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Costa KC, Bergkessel M, Saunders S, Korlach J, Newman DK. Enzymatic Degradation of Phenazines Can Generate Energy and Protect Sensitive Organisms from Toxicity. mBio 2015; 6:e01520-15. [PMID: 26507234 PMCID: PMC4626857 DOI: 10.1128/mbio.01520-15] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 10/05/2015] [Indexed: 11/29/2022] Open
Abstract
UNLABELLED Diverse bacteria, including several Pseudomonas species, produce a class of redox-active metabolites called phenazines that impact different cell types in nature and disease. Phenazines can affect microbial communities in both positive and negative ways, where their presence is correlated with decreased species richness and diversity. However, little is known about how the concentration of phenazines is modulated in situ and what this may mean for the fitness of members of the community. Through culturing of phenazine-degrading mycobacteria, genome sequencing, comparative genomics, and molecular analysis, we identified several conserved genes that are important for the degradation of three Pseudomonas-derived phenazines: phenazine-1-carboxylic acid (PCA), phenazine-1-carboxamide (PCN), and pyocyanin (PYO). PCA can be used as the sole carbon source for growth by these organisms. Deletion of several genes in Mycobacterium fortuitum abolishes the degradation phenotype, and expression of two genes in a heterologous host confers the ability to degrade PCN and PYO. In cocultures with phenazine producers, phenazine degraders alter the abundance of different phenazine types. Not only does degradation support mycobacterial catabolism, but also it provides protection to bacteria that would otherwise be inhibited by the toxicity of PYO. Collectively, these results serve as a reminder that microbial metabolites can be actively modified and degraded and that these turnover processes must be considered when the fate and impact of such compounds in any environment are being assessed. IMPORTANCE Phenazine production by Pseudomonas spp. can shape microbial communities in a variety of environments ranging from the cystic fibrosis lung to the rhizosphere of dryland crops. For example, in the rhizosphere, phenazines can protect plants from infection by pathogenic fungi. The redox activity of phenazines underpins their antibiotic activity, as well as providing pseudomonads with important physiological benefits. Our discovery that soil mycobacteria can catabolize phenazines and thereby protect other organisms against phenazine toxicity suggests that phenazine degradation may influence turnover in situ. The identification of genes involved in the degradation of phenazines opens the door to monitoring turnover in diverse environments, an essential process to consider when one is attempting to understand or control communities influenced by phenazines.
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Affiliation(s)
- Kyle C Costa
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Megan Bergkessel
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA Howard Hughes Medical Institute, Pasadena, California, USA
| | - Scott Saunders
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | | | - Dianne K Newman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA Howard Hughes Medical Institute, Pasadena, California, USA
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Núñez MC, Menéndez MC, Rebollo MJ, García MJ. Transcriptional analysis of Mycobacterium fortuitum cultures upon hydrogen peroxide treatment using the novel standard rrnA-P1. BMC Microbiol 2008; 8:100. [PMID: 18565220 PMCID: PMC2443159 DOI: 10.1186/1471-2180-8-100] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Accepted: 06/19/2008] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND The ability of an intracellular pathogen to establish infection depends on the capacity of the organism to survive and replicate inside the host. Mycobacterium fortuitum is a bacteria that contains genes involved in the detoxification of the oxygen reactive species such as those produced by the host during the infection. In this work, we investigate the effects of hydrogen peroxide on the transcription and expression of these genes by developing a real time quantitative PCR technique (qRT-PCR) using the ribosomal promoter region (rrnA-P1) as reference product for quantification of the mRNA levels. RESULTS M. fortuitum cultures were treated with different hydrogen peroxide concentrations (0.02 to 20 mM) during several periods of time (30 to 120 minutes). The activity of the enzymes KatGII and SodA, and the transcription of corresponding genes were evaluated. The transcriptional regulator furAII gene was also studied. The ribosomal promoter region rrnA-P1 was validated as referential product under the stress conditions checked by qRT-PCR. Minor changes were observed under the conditions tested except when bacteria were incubated in the presence of 20 mM hydrogen peroxide. Under those conditions, the levels of transcription of the three genes under study increased at 30 minutes of treatment. The viability of the bacteria was not influenced under the conditions tested. CONCLUSION In this work, we have quantified transcriptional responses to stress suggesting that, the opportunistic pathogen M. fortuitum is more resistant and differs in behaviour in the presence of hydrogen peroxide, when compared to the major pathogen Mycobacterium tuberculosis and the saprophyte Mycobacterium smegmatis. Besides, we demonstrate the mycobacterial non-coding region rrnA-P1 to be a suitable reference product in the analysis of qRT-PCR transcriptional data of M. fortuitum.
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Affiliation(s)
- María Carmen Núñez
- Departamento de Medicina Preventiva, Facultad de Medicina, Universidad Autónoma, c/Arzobispo Morcillo, 4, 28029-Madrid, Spain
- Departamento de Biotecnologia del INIA, Carretera de La Coruña, Km 7.5, 28040-Madrid, Spain
| | - María Carmen Menéndez
- Departamento de Medicina Preventiva, Facultad de Medicina, Universidad Autónoma, c/Arzobispo Morcillo, 4, 28029-Madrid, Spain
| | - María José Rebollo
- Departamento de Medicina Preventiva, Facultad de Medicina, Universidad Autónoma, c/Arzobispo Morcillo, 4, 28029-Madrid, Spain
- GlaxoSmithKline R&D, Diseases of the Developing World, Molecular Drug Discovery, C/Severo Ochoa, n° 2, 28760-Tres Cantos, Madrid, Spain
| | - María J García
- Departamento de Medicina Preventiva, Facultad de Medicina, Universidad Autónoma, c/Arzobispo Morcillo, 4, 28029-Madrid, Spain
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Lee SM, Kim JM, Jeong J, Park YK, Bai GH, Lee EY, Lee MK, Chang CL. Evaluation of the broth microdilution method using 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride for rapidly growing mycobacteria susceptibility testing. J Korean Med Sci 2007; 22:784-90. [PMID: 17982223 PMCID: PMC2693841 DOI: 10.3346/jkms.2007.22.5.784] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2006] [Accepted: 02/12/2007] [Indexed: 11/20/2022] Open
Abstract
As the incidence of nontuberculous mycobacterial infection has been increasing recently in Korea, the importance of drug susceptibility test for clinical isolates of mycobacteria has become larger. In this study we determined the antimicrobial susceptibility patterns of clinical isolates of M. fortuitum and M. abscessus in Korea, and evaluated the efficacy of a modified broth microdilution method using 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride (STC), in terms of its ability to provide accurate and easy-to-read minimal inhibitory concentration (MIC) endpoints for the susceptibility testing of rapidly growing mycobacteria. Most isolates of M. fortuitum and M. abscessus in Korea are susceptible or intermediately susceptible to amikacin, cefoxitin, ciprofloxacin, and clarithromycin. Many isolates of M. fortuitum are susceptible to doxycycline, sulfamethoxazole, and imipenem, while many M. abscessus isolates are resistant to these drugs. In the present study, the modified broth microdilution method using STC was found to be reliable, easy to read, and inexpensive for M. fortuitum and M. abscessus susceptibility testing. The modified colorimetric MIC testing method using STC was proven to be a useful surrogate for RGM antibiotic susceptibility testing.
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Affiliation(s)
- Sun Min Lee
- Department of Laboratory Medicine, School of Medicine, Pusan National University, Busan, Korea
| | - Jeong man Kim
- Department of Laboratory Medicine, Donga University College of Medicine, Busan, Korea
| | - Joseph Jeong
- Department of Laboratory Medicine, Ulsan University Hospital, Ulsan, Korea
| | | | | | - Eun Yup Lee
- Department of Laboratory Medicine, School of Medicine, Pusan National University, Busan, Korea
| | - Min Ki Lee
- Department of Internal Medicine, School of Medicine, Pusan National University, Busan, Korea
| | - Chulhun L. Chang
- Department of Laboratory Medicine, School of Medicine, Pusan National University, Busan, Korea
- Korean Institute of Tuberculosis, Seoul, Korea
- Medical Research Institute, Pusan National University, Busan, Korea
- MRC for Ischemic Tissue Regeneration, Pusan National University, Busan, Korea
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Ramón-García S, Martín C, Aínsa JA, De Rossi E. Characterization of tetracycline resistance mediated by the efflux pump Tap from Mycobacterium fortuitum. J Antimicrob Chemother 2005; 57:252-9. [PMID: 16373429 DOI: 10.1093/jac/dki436] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES The aim of this study was to characterize the efflux pump Tap from Mycobacterium fortuitum, to test its sensitivity to well known efflux inhibitors, to study the interaction between tetracycline and these compounds and to test the ability of these compounds to overcome efflux pump-mediated tetracycline resistance. For all these studies, we produced Tap protein in Mycobacterium smegmatis. METHODS Antibiotic susceptibility tests, tetracycline uptake/efflux experiments and checkerboard synergy tests. RESULTS Tetracycline uptake/efflux experiments showed that Tap protein from M. fortuitum uses the electrochemical gradient across the cytoplasmic membrane to extrude tetracycline from the cell. This efflux activity is inhibited by carbonyl cyanide m-chlorophenylhydrazone (CCCP) and reserpine, consistent with the decrease in MIC observed in antibiotic susceptibility testing in the presence of these inhibitors. Accumulation was not inhibited in experiments in which o-vanadate and chlorpromazine (CPZ) were tested. Inhibitor-treated cells used glycerol as a carbon source to re-establish the electrochemical gradient across the membrane and to restore efflux activity. CCCP, reserpine and CPZ reduced the MIC of tetracycline in the M. smegmatis strain expressing the Tap protein, whereas o-vanadate increased the MIC. We also observed synergy between tetracycline and CPZ or reserpine, and antagonism with o-vanadate. CONCLUSIONS The Tapfor efflux pump uses the electrochemical gradient to extrude tetracycline from the cell. This efflux activity can be inhibited by several compounds. This suggests that similar compounds could be used to overcome antibiotic resistance mediated by efflux pumps.
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Affiliation(s)
- Santiago Ramón-García
- Departamento de Microbiología, Medicina Preventiva y Salud Pública, Universidad de Zaragoza, 50009 Zaragoza, Spain
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Ling LF, Ge M, Fu L, Huang WY, Chen DJ. [Mechanism study on difference of biotransformation between Mycobacterium fortuitum MF2 and MF96]. Wei Sheng Wu Xue Bao 2005; 45:526-9. [PMID: 16245863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Biotransformation difference between parent strain (MF2) and mutant strain (MF96) of Mycobacterium fortuitum was observed. Biotransformation with resting cells showed that the major products of biotransformation by both parent and mutant strains are delta4-androstenedione(4AD) and testosterone(TS). Experiments with cell-free extract system showed that the proportion of 4AD/TS obtained from parent and mutant strains was almost same when enough NAD+ and NADH were supplied in this system. It was suggested that the difference of the ratio of products transformed by both strains in resting cell system may result from their different ratio of NAD+/NADH. This speculation was verified to be true by determination of the amount of NAD+ and NADH presented in both strains.
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Affiliation(s)
- Liang-Fei Ling
- Department of Microbiology, Nanjing Agricultural University, Nanjing 210095, China.
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Menéndez MDC, Rebollo MJ, Núñez MDC, Cox RA, García MJ. Analysis of the precursor rRNA fractions of rapidly growing mycobacteria: quantification by methods that include the use of a promoter (rrnA P1) as a novel standard. J Bacteriol 2005; 187:534-43. [PMID: 15629925 PMCID: PMC543529 DOI: 10.1128/jb.187.2.534-543.2005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mycobacterial species are able to control rRNA production through variations in the number and strength of promoters controlling their rrn operons. Mycobacterium chelonae and M. fortuitum are members of the rapidly growing mycobacterial group. They carry a total of five promoters each, encoded, respectively, by one and two rrn operons per genome. Quantification of precursor rrn transcriptional products (pre-rrn) has allowed detection of different promoter usage during cell growth. Bacteria growing in several culture media with different nutrient contents were compared. Balanced to stationary phases were analyzed. Most promoters were found to be used at different levels depending on the stage of bacterial growth and the nutrient content of the culture medium. Some biological implications are discussed. Sequences of the several promoters showed motifs that could be correlated to their particular level of usage. A product corresponding to the first rrnA promoter in both species, namely, rrnA P1, was found to contribute at a low and near-constant level to pre-rRNA synthesis, regardless of the culture medium used and the stage of growth analyzed. This product was used as a standard to quantitate rRNA gene expression by real-time PCR when M. fortuitum infected macrophages. It was shown that this bacterium actively synthesizes rRNA during the course of infection and that one of its rrn operons is preferentially used under such conditions.
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Affiliation(s)
- María Del Carmen Menéndez
- Departamento de Medicina Preventiva, Facultad de Medicina, Universidad Autonoma de Madrid, Arzobispo Morcillo s/n, 28029 Madrid, Spain
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López-Marín LM, Segura E, Hermida-Escobedo C, Lemassu A, Salinas-Carmona MC. 6,6'-Dimycoloyl trehalose from a rapidly growing Mycobacterium: an alternative antigen for tuberculosis serodiagnosis. FEMS Immunol Med Microbiol 2003; 36:47-54. [PMID: 12727365 DOI: 10.1016/s0928-8244(03)00036-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Mycobacterial O-acyltrehaloses have been described as highly specific and sensitive reagents for tuberculosis immunodiagnosis. An O-acyltrehalose-containing lipid fraction from the rapidly growing Mycobacterium fortuitum was found to include additional antigens, which presented high cross-reactivity with sera from tuberculosis-infected patients. Based on a combination of selective chemical degradations, thin-layer-chromatography analyses and (1)H-nuclear magnetic resonance spectroscopy, the antigenic by-product was identified as 6,6'-dimycoloyl trehalose, the so-called cord factor. The lipid was purified and tested in ELISA for pulmonary tuberculosis serodiagnosis. Sensitivity and specificity of the test were found to be 66.6-74.1% and 95.2-99.0%, respectively, showing a slightly higher efficiency as compared to the ELISA performed using 6,6'-dimycoloyl trehalose from Mycobacterium tuberculosis. No cross-reactivity was found with sera from Nocardia-infected individuals.
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Affiliation(s)
- Luz M López-Marín
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apdo. Postal 70-228, C.U. Circuito Escolar, 04510 Coyoacán D.F., Mexico.
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Aínsa JA, Blokpoel MC, Otal I, Young DB, De Smet KA, Martín C. Molecular cloning and characterization of Tap, a putative multidrug efflux pump present in Mycobacterium fortuitum and Mycobacterium tuberculosis. J Bacteriol 1998; 180:5836-43. [PMID: 9811639 PMCID: PMC107655 DOI: 10.1128/jb.180.22.5836-5843.1998] [Citation(s) in RCA: 143] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/1998] [Accepted: 09/04/1998] [Indexed: 11/20/2022] Open
Abstract
A recombinant plasmid isolated from a Mycobacterium fortuitum genomic library by selection for gentamicin and 2-N'-ethylnetilmicin resistance conferred low-level aminoglycoside and tetracycline resistance when introduced into M. smegmatis. Further characterization of this plasmid allowed the identification of the M. fortuitum tap gene. A homologous gene in the M. tuberculosis H37Rv genome has been identified. The M. tuberculosis tap gene (Rv1258 in the annotated sequence of the M. tuberculosis genome) was cloned and conferred low-level resistance to tetracycline when introduced into M. smegmatis. The sequences of the putative Tap proteins showed 20 to 30% amino acid identity to membrane efflux pumps of the major facilitator superfamily (MFS), mainly tetracycline and macrolide efflux pumps, and to other proteins of unknown function but with similar antibiotic resistance patterns. Approximately 12 transmembrane regions and different sequence motifs characteristic of the MFS proteins also were detected. In the presence of the protonophore carbonyl cyanide m-chlorophenylhydrazone (CCCP), the levels of resistance to antibiotics conferred by plasmids containing the tap genes were decreased. When tetracycline accumulation experiments were carried out with the M. fortuitum tap gene, the level of tetracycline accumulation was lower than that in control cells but was independent of the presence of CCCP. We conclude that the Tap proteins of the opportunistic organism M. fortuitum and the important pathogen M. tuberculosis are probably proton-dependent efflux pumps, although we cannot exclude the possibility that they act as regulatory proteins.
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Affiliation(s)
- J A Aínsa
- Departamento de Microbiología Medicina Preventiva y Salud Pública, Universidad de Zaragoza, 50009 Zaragoza, Spain
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Chou S, Chedore P, Kasatiya S. Use of gas chromatographic fatty acid and mycolic acid cleavage product determination to differentiate among Mycobacterium genavense, Mycobacterium fortuitum, Mycobacterium simiae, and Mycobacterium tuberculosis. J Clin Microbiol 1998; 36:577-9. [PMID: 9466781 PMCID: PMC104582 DOI: 10.1128/jcm.36.2.577-579.1998] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Three Mycobacterium genavense strains and three American Type Culture Collection reference strains each of Mycobacterium fortuitum, Mycobacterium simiae, and Mycobacterium tuberculosis were subcultured onto Mycobacteria 7H11 agar (Difco Laboratories, Detroit, Mich.) supplemented with mycobactin J (Allied Laboratories, Fayette, Mo.). After 4 weeks of incubation at 37 degrees C in 10% CO2, the cultures were analyzed by gas-liquid chromatography (GLC) for their fatty acids and mycolic acid cleavage products. M. fortuitum was clearly differentiated from M. genavense by the presence of the specific marker 2-methyloctadecenoic acid in M. fortuitum and by the ratio of tetracosanoic acid to hexacosanoic acid. This ratio was <1 for M. genavense and >3 for M. fortuitum. M. fortuitum also contained docosanoic acid, which was not detected in M. genavense. M. genavense, M. simiae, and M. tuberculosis, which have similar GLC profiles, were also differentiated from each other by the presence of either cis-10-hexadecenoic acid or cis-11-hexadecenoic acid and by tetradecanoic acid content.
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Affiliation(s)
- S Chou
- Public Health Laboratory, Ontario Ministry of Health, Ottawa, Canada.
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Gonzalez-y-Merchand JA, Garcia MJ, Gonzalez-Rico S, Colston MJ, Cox RA. Strategies used by pathogenic and nonpathogenic mycobacteria to synthesize rRNA. J Bacteriol 1997; 179:6949-58. [PMID: 9371439 PMCID: PMC179633 DOI: 10.1128/jb.179.22.6949-6958.1997] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
One rRNA operon of all mycobacteria studied so far is located downstream from a gene thought to code for the enzyme UDP-N-acetylglucosamine carboxyvinyl transferase (UNAcGCT), which is important to cell wall synthesis. This operon has been designated rrnAf for fast-growing mycobacteria and rrnAs for slow growers. We have investigated the upstream sequences and promoter activities of rrnA operons of typical fast growers which also possess a second rrn (rrnBf) operon and of the rrnA operons of the fast growers Mycobacterium abscessus and Mycobacterium chelonae, which each have a single rrn operon per genome. These fast growers have a common strategy for increasing the efficiency of transcription of their rrnA operons, thereby increasing the cells' potential for ribosome synthesis. This strategy involves the use of multiple (three to five) promoters which may have arisen through successive duplication events. Thus we have identified a hypervariable multiple promoter region (HMPR) located between the UNAcGCT gene and the 16S rRNA coding region. Two promoters, P1 and PCL1, appear to play pivotal roles in mycobacterial rRNA synthesis; they are present in all of the species examined and are the only promoters used for rRNA synthesis by the pathogenic slow growers. P1 is located within the coding region of the UNAcGCT gene, and PCL1 has a characteristic sequence that is related to but distinct from that of the additional promoters. In fast-growing species, P1 and PCL1 produce less than 10% of rRNA transcripts, so the additional promoters found in the HMPR are important in increasing the potential for rRNA synthesis during rapid growth. In contrast, rrnB operons appear to be regulated by a single promoter; because less divergence has taken place, rrnB appears to be younger than rrnA.
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MESH Headings
- Base Sequence
- Chromosome Mapping
- Cloning, Molecular
- DNA, Bacterial/genetics
- Gene Expression Regulation, Bacterial
- Genes, Bacterial
- Genome, Bacterial
- Molecular Sequence Data
- Molecular Structure
- Mycobacterium/genetics
- Mycobacterium/metabolism
- Mycobacterium/pathogenicity
- Mycobacterium chelonae/genetics
- Mycobacterium chelonae/metabolism
- Mycobacterium chelonae/pathogenicity
- Mycobacterium fortuitum/genetics
- Mycobacterium fortuitum/metabolism
- Mycobacterium fortuitum/pathogenicity
- Mycobacterium phlei/genetics
- Mycobacterium phlei/metabolism
- Mycobacterium phlei/pathogenicity
- Plasmids
- Polymerase Chain Reaction
- Promoter Regions, Genetic
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Ribosomal/chemistry
- RNA, Ribosomal/metabolism
- RNA, Ribosomal, 16S/genetics
- Ribosomes/metabolism
- Sequence Alignment
- Sequence Analysis, DNA
- Transcription, Genetic
- Virulence/genetics
- rRNA Operon
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Affiliation(s)
- J A Gonzalez-y-Merchand
- Division of Mycobacterial Research, National Institute for Medical Research, The Ridgeway, London, United Kingdom
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Abstract
It has been suggested that catalase-peroxidase plays an important role in several aspects of mycobacterial metabolism and is a virulence factor in the main pathogenic mycobacteria. In this investigation, we studied genes encoding for this protein in the fast-growing opportunistic pathogen Mycobacterium fortuitum. Nucleotide sequences of two different catalase-peroxidase genes (katGI and katGII) of M. fortuitum are described. They show only 64% homology at the nucleotide level and 55% identity at the amino acid level, and they are more similar to catalases-peroxidases from different bacteria, including mycobacteria, than to each other. Both proteins were found to be expressed in actively growing M. fortuitum, and both could also be expressed when transformed into Escherichia coli and M. aurum. We detected the presence of a copy of IS6100 in the neighboring region of a katG gene in the M. fortuitum strain in which this element was identified (strain FC1). The influence of each katG gene on isoniazid (isonicotinic acid hydrazide; INH) susceptibility of mycobacteria was checked by using the INH-sensitive M. aurum as the host. Resistance to INH was induced when katGI was transformed into INH-sensitive M. aurum, suggesting that this enzyme contributes to the natural resistance of M. fortuitum to the drug. This is the first report showing two different genes encoding same enzyme activity which are actively expressed within the same mycobacterial strain.
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Affiliation(s)
- M C Menéndez
- Departamento Medicina Preventiva, Facultad de Medicina, Universidad Autónoma de Madrid, Spain
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15
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Abstract
The regulatory region of the Mycobacterium fortuitum plasmid pAL5000 was studied in vivo and in vitro by mutational analysis. This region comprises the origin of replication for the plasmid and the start point of transcription for the repA/B genes, which encode the two replication proteins RepA and RepB. In this region there are two binding sites for RepB: a low-affinity site which is probably the origin of replication and a high-affinity-site which overlaps the promoter and implies an autoregulated expression of RepB. The high-affinity site contains two 8 bp palindromes, as well as an inverted repeat structure. By introducing point mutations into each of these motifs and monitoring changes to RepB binding in a gel-retardation assay, it was shown that the central, GC-rich palindrome (the GC-box) is the most important motif for protein binding. Mutations in the second, AT-rich palindrome (the AT-box) had no effect on protein binding and the inverted repeat structure per se was not needed, though some single-base changes affected binding to one or other of the DNA strands. These mutations were subsequently tested in vivo for their effects on plasmid replication in Mycobacterium smegmatis. Any change to the GC-box abolished replication, but changes to the other motifs were dependent on the position of the changed base, again indicating that the inverted repeats are not essential and that the AT-box is part of the promoter and not primarily recognised by RepB. The mutated plasmids did not show any changes in copy number to that of the wild-type. The expression of RepB was boosted by introducing a stronger promoter upstream of the repA/B genes. The resulting plasmid was capable of increasing to a degree in trans the copy number of other plasmids carrying the ori region, but was unstable when present on its own in M.smegmatis.
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Affiliation(s)
- P Stolt
- Department of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
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