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Mvubu NE, Jacoby K. Mycobacterium tuberculosis complex molecular networks and their regulation: Implications of strain heterogeneity on epigenetic diversity and transcriptome regulation. Heliyon 2023; 9:e22611. [PMID: 38046135 PMCID: PMC10686871 DOI: 10.1016/j.heliyon.2023.e22611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 11/13/2023] [Accepted: 11/15/2023] [Indexed: 12/05/2023] Open
Abstract
Tuberculosis has been a public health crisis since the 1900, which has caused the highest mortalities due to a single bacterial infection worldwide, that was recently further complicated by the Coronavirus disease 2019 pandemic. The causative agent of Tuberculosis, Mycobacterium tuberculosis, belongs to a genetically well-characterized family of strains known as the Mycobacterium tuberculosis complex, which has complicated progress made towards eradicating Tuberculosis due to pathogen-specific phenotypic differences in the members of this complex. Mycobacterium tuberculosis complex strains are genetically diverse human- and animal-adapted pathogens belonging to 7 lineages (Indo-Oceanic, East-Asian, East-African Indian, Euro-American, M. africanum West Africa 1, M. africanum West Africa 2 and Ethopia), respectively and the recently identified Lineage 8 and M. africanum Lineage 9. Genomic studies have revealed that Mycobacterium tuberculosis complex members are ∼99 % similar, however, due to selective pressure and adaptation to human host, they are prone to mutations that have resulted in development of drug resistance and phenotypic heterogeneity that impact strain virulence. Furthermore, members of the Mycobacterium tuberculosis complex have preferred geographic locations and possess unique phenotypic characteristics that is linked to their pathogenicity. Due to the recent advances in development next generation sequencing platforms, several studies have revealed epigenetic changes in genomic regions combined with "unique" gene regulatory mechanisms through non-coding RNAs that are responsible for strain-specific behaviour on in vitro and in vivo infection models. The current review provides up to date epigenetic patterns, gene regulation through non-coding RNAs, together with implications of these mechanisms in down-stream proteome and metabolome, which may be responsible for "unique" responses to infection by members of the Mycobacterium tuberculosis complex. Understanding lineage-specific molecular mechanisms during infection may provide novel drug targets and disease control measures towards World Health organization END-TB strategy.
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Affiliation(s)
- Nontobeko Eunice Mvubu
- Medical Microbiology, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, 4000, South Africa
| | - Kieran Jacoby
- Medical Microbiology, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, 4000, South Africa
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Kumar C, Shrivastava K, Singh A, Chauhan V, Giri A, Gupta S, Sharma NK, Bose M, Sharma S, Varma-Basil M. Expression of mammalian cell entry genes in clinical isolates of M. tuberculosis and the cell entry potential and immunological reactivity of the Rv0590A protein. Med Microbiol Immunol 2023; 212:407-419. [PMID: 37787822 DOI: 10.1007/s00430-023-00781-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/31/2023] [Indexed: 10/04/2023]
Abstract
Mammalian cell entry (mce) operons play a vital role in cell invasion and survival of M. tuberculosis. Of the mce genes, the function of Rv0590A is still unknown. The present study was performed to investigate the function and immunogenic properties of the protein Rv0590A. Human leukemia monocytic cell line (THP-1) derived macrophages were infected with M. tuberculosis H37Rv at 3, 6, and 24 h of infection. The maximum colony forming units (CFU) were observed at 6 h (p < 0.005), followed by 3 h after infection. M. tuberculosis H37Rv and clinical isolates representative of Delhi/CAS, EAI, Beijing, Haarlem and Euro-American-superlineage were included in the study for expression analysis of mce1A, mce2A, mce3A, mce4A, and Rv0590A genes. Maximum upregulation of all mce genes was observed at 3 h of infection. All the five clinical isolates and H37Rv upregulated Rv0590A at various time points. Macrophage infection with M. tuberculosis H37Rv-overexpressing Rv0590A gene showed higher intracellular CFU as compared to that of wild-type H37Rv. Further, purified Rv0590A protein stimulated the production of TNFα, IFNγ, and IL-10 in macrophages. Thus, Rv0590A was found to be involved in cell invasion and showed good immunological response.
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Affiliation(s)
- Chanchal Kumar
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, 110007, India
| | - Kamal Shrivastava
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, 110007, India
| | - Anupriya Singh
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, 110007, India
| | - Varsha Chauhan
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, 110007, India
- Maharshi Dayanand University, Rohtak, Haryana, India
| | - Astha Giri
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, 110007, India
- Deshbandhu College, University of Delhi, Delhi, India
| | - Shraddha Gupta
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, 110007, India
| | - Naresh Kumar Sharma
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, 110007, India
- University of Manitoba, Winnipeg, MB, Canada
| | - Mridula Bose
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, 110007, India
| | - Sadhna Sharma
- Department of Zoology, Miranda House, University of Delhi, Delhi, 110007, India
| | - Mandira Varma-Basil
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, 110007, India.
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Abstract
Mycobacteria have unique cell envelopes, surface properties, and growth dynamics, which all play a part in the ability of these important pathogens to infect, evade host immunity, disseminate, and resist antibiotic challenges. Recent atomic force microscopy (AFM) studies have brought new insights into the nanometer-scale ultrastructural, adhesive, and mechanical properties of mycobacteria. The molecular forces with which mycobacterial adhesins bind to host factors, like heparin and fibronectin, and the hydrophobic properties of the mycomembrane have been unraveled by AFM force spectroscopy studies. Real-time correlative AFM and fluorescence imaging have delineated a complex interplay between surface ultrastructure, tensile stresses within the cell envelope, and cellular processes leading to division. The unique capabilities of AFM, which include subdiffraction-limit topographic imaging and piconewton force sensitivity, have great potential to resolve important questions that remain unanswered on the molecular interactions, surface properties, and growth dynamics of this important class of pathogens.
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Infection of pulmonary epithelial cells by clinical strains of M. tuberculosis induces alternate splicing events. Gene 2020; 750:144755. [PMID: 32380040 DOI: 10.1016/j.gene.2020.144755] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/29/2020] [Accepted: 05/01/2020] [Indexed: 11/21/2022]
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Moopanar K, Mvubu NE. Lineage-specific differences in lipid metabolism and its impact on clinical strains of Mycobacterium tuberculosis. Microb Pathog 2020; 146:104250. [PMID: 32407863 DOI: 10.1016/j.micpath.2020.104250] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 04/01/2020] [Accepted: 05/06/2020] [Indexed: 01/02/2023]
Abstract
Mycobacterium tuberculosis (M. tb) is the causative agent of TB and its incidences has been on the rise since 1993. Lipid metabolism is an imperative metabolic process, which grants M. tb the ability to utilize host-derived lipids as a secondary source of nutrition during infection. In addition to degrading host lipids, M. tb is proficient at using lipids, such as cholesterol, to facilitate its entry into macrophages. Mycolic acids, constituents of the mycobacterial cell wall, offer protection and aid in persistence of the bacterium. These are effectively synthesized using a complex fatty acid synthase system. Many pathogenesis studies have reported differences in lipid-metabolism of clinical strains of M. tb that belongs to diverse lineages of the Mycobacterium tuberculosis complex (MTBC). East-Asian and Euro-American lineages possess "unique" cell wall-associated lipids compared to the less transmissible Ethiopian lineage, which may offer these lineages a competitive advantage. Therefore, it is crucial to comprehend the complexities among the MTBC lineages with lipid metabolism and their impact on virulence, transmissibility and pathogenesis. Thus, this review provides an insight into lipid metabolism in various lineages of the MTBC and their impact on virulence and persistence during infection, as this may provide critical insight into developing novel therapeutics to combat TB.
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Affiliation(s)
- K Moopanar
- School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, South Africa.
| | - N E Mvubu
- School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, South Africa.
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Cervantes JL, Oak E, Garcia J, Liu H, Lorenzini PA, Batra D, Chhabra A, Salazar JC, Roca X. Vitamin D modulates human macrophage response to Mycobacterium tuberculosis DNA. Tuberculosis (Edinb) 2019; 116S:S131-S137. [PMID: 31085128 PMCID: PMC6626683 DOI: 10.1016/j.tube.2019.04.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 11/01/2018] [Indexed: 12/12/2022]
Abstract
Mycobacterium tuberculosis (Mtb) is a facultative intracellular pathogen that infects macrophages where it avoids elimination by interfering with host defense mechanisms, including phago-lysosome fusion. Endosomal Toll-like receptors (TLRs) generate Type I Interferons (IFNs), which are associated with active tuberculosis (TB). We aimed to explore if DNA from different Mtb lineages lead to differences in the inflammatory response of human monocytic/macrophage cells. THP-1 cells which express two inducible reporter constructs for interferons (IFNs) as well as for NF-κB, were stimulated via endosomal delivery of Mtb DNA as a nanocomplex with PEI. DNA from different Mtb phylogenetic lineages elicited differential inflammatory responses in human macrophages. An initial relatively weak IRF-mediated response to DNA from HN878 and H37Rv increased if the cells were pre-treated with Vitamin D (Vit D) for 72 h. RNAseq of THP-1 under different transformation conditions showed that pre-treatment with Vit D upregulated several TLR9 variants, as well as genes involved in inflammatory immune response to infection, immune cell activation, Type I IFN regulation, and regulation of inflammation. Vit D appears to be important in increasing low IRF responses to DNA from certain lineages of Mtb. Variations in the IRF-mediated response to DNA derived from different Mtb genotypes are potentially important in the pathogenesis of tuberculosis since Type I IFN responses are associated with active disease. The role of Vit D in these responses could also translate into future therapeutic approaches.
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Affiliation(s)
- Jorge L Cervantes
- Texas Tech University Health Sciences Center, Paul L. Foster School of Medicine, El Paso, TX, USA.
| | - Esther Oak
- University of New England, College of Dental Medicine, Portland, ME, USA
| | - John Garcia
- University of Connecticut Health, School of Public Health, Farmington, CT, USA
| | - Hongfei Liu
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Paolo A Lorenzini
- School of Biological Sciences, Nanyang Technological University, Singapore; Nanyang Institute of Technology in Health and Medicine, Interdisciplinary Graduate School, Nanyang Technological University, Singapore
| | - Deepika Batra
- Stem Cell Institute, Amity University Haryana, Manesar, Gurugram, Haryana, India
| | - Arvind Chhabra
- Stem Cell Institute, Amity University Haryana, Manesar, Gurugram, Haryana, India
| | - Juan C Salazar
- University of Connecticut Health, Department of Pediatrics, Farmington, CT, USA; Connecticut Children's Medical Center, Hartford, CT, USA
| | - Xavier Roca
- School of Biological Sciences, Nanyang Technological University, Singapore
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Mvubu NE, Pillay B, McKinnon LR, Pillay M. Mycobacterium tuberculosis strains induce strain-specific cytokine and chemokine response in pulmonary epithelial cells. Cytokine 2017; 104:53-64. [PMID: 29032986 DOI: 10.1016/j.cyto.2017.09.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 09/23/2017] [Accepted: 09/23/2017] [Indexed: 02/07/2023]
Abstract
M. tuberculosis F15/LAM4/KZN has been associated with high transmission rates of drug resistant tuberculosis in the KwaZulu-Natal province of South Africa. The current study elucidated the cytokine/chemokine responses induced by representatives of the F15/LAM4/KZN and other dominant strain families in pulmonary epithelial cells. Multiplex cytokine analyses were performed at 24, 48 and 72h post infection of the A549 pulmonary epithelial cell line with the F15/LAM4/KZN, F28, F11, Beijing, Unique and H37Rv strains at an MOI of ∼10:1. Twenty-three anti- and pro-inflammatory cytokines/chemokines were detected at all-time intervals. Significantly high concentrations of IL-6, IFN-γ, TNF-α and G-CSF at 48h, and IL-8, IFN-γ, TNF-α, G-CSF and GM-CSF at 72h, were induced by the F28 and F15/LAM4/KZN strains, respectively. Lower levels of cytokines/chemokines were induced by either the Beijing or Unique strains at all three time intervals. All strains induced up-regulation of pathogen recognition receptors (PRRs) (TLR3 and TLR5) while only the F15/LAM4/KZN, F11 and F28 strains induced significant differential expression of TLR2 compared to the Beijing, Unique and H37Rv strains. The low induction of cytokines in epithelial cells by the Beijing strain correlates with its previously reported hypervirulent properties. High concentrations of cytokines and chemokines required for early protection against M. tuberculosis infections induced by the F15/LAM4/KZN and F28 strains suggests a lower virulence of these genotypes compared to the Beijing strain. These findings demonstrate the high diversity in host cytokine/chemokine response to early infection of pulmonary epithelial cells by different strains of M. tuberculosis.
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Affiliation(s)
- Nontobeko E Mvubu
- School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville 3630, South Africa.
| | - Balakrishna Pillay
- School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville 3630, South Africa.
| | - Lyle R McKinnon
- Centre for the AIDS Program of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa; Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.
| | - Manormoney Pillay
- Medical Microbiology, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, 719 Umbilo Road, South Africa.
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Datta S, Sherman JM, Tovar MA, Bravard MA, Valencia T, Montoya R, Quino W, D'Arcy N, Ramos ES, Gilman RH, Evans CA. Sputum Microscopy With Fluorescein Diacetate Predicts Tuberculosis Infectiousness. J Infect Dis 2017; 216:514-524. [PMID: 28510693 PMCID: PMC5853787 DOI: 10.1093/infdis/jix229] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 05/11/2017] [Indexed: 01/03/2023] Open
Abstract
Background Sputum from patients with tuberculosis contains subpopulations of metabolically active and inactive Mycobacterium tuberculosis with unknown implications for infectiousness. Methods We assessed sputum microscopy with fluorescein diacetate (FDA, evaluating M. tuberculosis metabolic activity) for predicting infectiousness. Mycobacterium tuberculosis was quantified in pretreatment sputum of patients with pulmonary tuberculosis using FDA microscopy, culture, and acid-fast microscopy. These 35 patients’ 209 household contacts were followed with prevalence surveys for tuberculosis disease for 6 years. Results FDA microscopy was positive for a median of 119 (interquartile range [IQR], 47–386) bacteria/µL sputum, which was 5.1% (IQR, 2.4%–11%) the concentration of acid-fast microscopy–positive bacteria (2069 [IQR, 1358–3734] bacteria/μL). Tuberculosis was diagnosed during follow-up in 6.4% (13/209) of contacts. For patients with lower than median concentration of FDA microscopy–positive M. tuberculosis, 10% of their contacts developed tuberculosis. This was significantly more than 2.7% of the contacts of patients with higher than median FDA microscopy results (crude hazard ratio [HR], 3.8; P = .03). This association maintained statistical significance after adjusting for disease severity, chemoprophylaxis, drug resistance, and social determinants (adjusted HR, 3.9; P = .02). Conclusions Mycobacterium tuberculosis that was FDA microscopy negative was paradoxically associated with greater infectiousness. FDA microscopy–negative bacteria in these pretreatment samples may be a nonstaining, slowly metabolizing phenotype better adapted to airborne transmission.
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Affiliation(s)
- Sumona Datta
- Innovation for Health and Development (IFHAD), Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru.,Infectious Diseases and Immunity and Wellcome Trust Centre for Global Health Research, Imperial College London, United Kingdom.,Innovacion por la Salud y el Desarollo (IPSYD), Asociación Benéfica Prisma, Lima, Peru
| | - Jonathan M Sherman
- Innovation for Health and Development (IFHAD), Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Marco A Tovar
- Innovation for Health and Development (IFHAD), Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru.,Innovacion por la Salud y el Desarollo (IPSYD), Asociación Benéfica Prisma, Lima, Peru
| | - Marjory A Bravard
- Innovation for Health and Development (IFHAD), Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Teresa Valencia
- Innovation for Health and Development (IFHAD), Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Rosario Montoya
- Innovacion por la Salud y el Desarollo (IPSYD), Asociación Benéfica Prisma, Lima, Peru
| | - Willi Quino
- Innovation for Health and Development (IFHAD), Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru.,Innovacion por la Salud y el Desarollo (IPSYD), Asociación Benéfica Prisma, Lima, Peru
| | - Nikki D'Arcy
- Innovation for Health and Development (IFHAD), Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru.,Innovacion por la Salud y el Desarollo (IPSYD), Asociación Benéfica Prisma, Lima, Peru
| | - Eric S Ramos
- Innovation for Health and Development (IFHAD), Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Robert H Gilman
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Carlton A Evans
- Innovation for Health and Development (IFHAD), Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru.,Infectious Diseases and Immunity and Wellcome Trust Centre for Global Health Research, Imperial College London, United Kingdom.,Innovacion por la Salud y el Desarollo (IPSYD), Asociación Benéfica Prisma, Lima, Peru
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Mvubu NE, Pillay B, Gamieldien J, Bishai W, Pillay M. Canonical pathways, networks and transcriptional factor regulation by clinical strains of Mycobacterium tuberculosis in pulmonary alveolar epithelial cells. Tuberculosis (Edinb) 2015; 97:73-85. [PMID: 26980499 DOI: 10.1016/j.tube.2015.12.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 11/30/2015] [Accepted: 12/10/2015] [Indexed: 12/12/2022]
Abstract
Limited knowledge exists on pathways, networks and transcriptional factors regulated within epithelial cells by diverse Mycobacterium tuberculosis genotypes. This study aimed to elucidate these mechanisms induced in A549 epithelial cells by dominant clinical strains in KwaZulu-Natal, South Africa. RNA for sequencing was extracted from epithelial cells at 48 h post-infection with 5 strains at a multiplicity of infection of approximately 10:1. Bioinformatics analysis performed with the RNA-Seq Tuxedo pipeline identified differentially expressed genes. Changes in pathways, networks and transcriptional factors were identified using Ingenuity Pathway Analysis (IPA). The interferon signalling and hepatic fibrosis/hepatic stellate cell activation pathways were among the top 5 canonical pathways in all strains. Hierarchical clustering for enrichment of cholesterol biosynthesis and immune associated pathways revealed similar patterns for Beijing and Unique; F15/LAM4/KZN and F11; and, F28 and H37Rv strains, respectively. However, the induction of top scoring networks varied among the strains. Among the transcriptional factors, only EHL, IRF7, PML, STAT1, STAT2 and VDR were induced by all clinical strains. Activation of the different pathways, networks and transcriptional factors revealed in the current study may be an underlying mechanism that results in the differential host response by clinical strains of M. tuberculosis.
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Affiliation(s)
- Nontobeko E Mvubu
- School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville 3630, South Africa.
| | - Balakrishna Pillay
- School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville 3630, South Africa.
| | - Junaid Gamieldien
- South African National Bioinformatics Institute/MRC Unit for Bioinformatics Capacity Development, University of the Western Cape, Bellville 7530, South Africa.
| | - William Bishai
- Department of Medicine, Division of Infectious Diseases, Johns Hopkins School of Medicine, 1550 Orleans St., Baltimore, MD, United State of America.
| | - Manormoney Pillay
- Medical Microbiology and Infection Control, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, 719 Umbilo Road, Private Bag 7, Congella 4013, Durban, South Africa.
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The microbiome at the pulmonary alveolar niche and its role in Mycobacterium tuberculosis infection. Tuberculosis (Edinb) 2015; 95:651-658. [PMID: 26455529 DOI: 10.1016/j.tube.2015.07.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/08/2015] [Accepted: 07/13/2015] [Indexed: 01/14/2023]
Abstract
Advances in next generation sequencing (NGS) technology have provided the tools to comprehensively and accurately characterize the microbial community in the respiratory tract in health and disease. The presence of commensal and pathogenic bacteria has been found to have important effects on the lung immune system. Until relatively recently, the lung has received less attention compared to other body sites in terms of microbiome characterization, and its study carries special technological difficulties related to obtaining reliable samples as compared to other body niches. Additionally, the complexity of the alveolar immune system, and its interactions with the lung microbiome, are only just beginning to be understood. Amidst this complexity sits Mycobacterium tuberculosis (Mtb), one of humanity's oldest nemeses and a significant public health concern, with millions of individuals infected with Mtb worldwide. The intricate interactions between Mtb, the lung microbiome, and the alveolar immune system are beginning to be understood, and it is increasingly apparent that improved treatment of Mtb will only come through deep understanding of the interplay between these three forces. In this review, we summarize our current understanding of the lung microbiome, alveolar immunity, and the interaction of each with Mtb.
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Sturm A, Ashiru O. Cytotoxicity Induction in A549 Alveolar Epithelial Cells by Mycobacterium tuberculosis Isolates Cultured in the Presence and Absence of Oxygen. ACTA ACUST UNITED AC 2015. [DOI: 10.6000/1927-5129.2015.11.16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Gandhi NR, Brust JCM, Moodley P, Weissman D, Heo M, Ning Y, Moll AP, Friedland GH, Sturm AW, Shah NS. Minimal diversity of drug-resistant Mycobacterium tuberculosis strains, South Africa. Emerg Infect Dis 2015; 20:426-33. [PMID: 24565645 PMCID: PMC3944869 DOI: 10.3201/eid2003.131083] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Multidrug- (MDR) and extensively drug-resistant tuberculosis (XDR TB) are commonly associated with Beijing strains. However, in KwaZulu-Natal, South Africa, which has among the highest incidence and mortality for MDR and XDR TB, data suggest that non-Beijing strains are driving the epidemic. We conducted a retrospective study to characterize the strain prevalence among drug-susceptible, MDR, and XDR TB cases and determine associations between strain type and survival. Among 297 isolates from 2005–2006, 49 spoligotype patterns were found. Predominant strains were Beijing (ST1) among drug-susceptible isolates (27%), S/Quebec (ST34) in MDR TB (34%) and LAM4/KZN (ST60) in XDR TB (89%). More than 90% of patients were HIV co-infected. MDR TB and XDR TB were independently associated with mortality, but TB strain type was not. We conclude that, although Beijing strain was common among drug-susceptible TB, other strains predominated among MDR TB and XDR TB cases. Drug-resistance was a stronger predictor of survival than strain type.
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