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Jia J, Zhang M, Cao Z, Hu X, Lei S, Zhang Y, Kang X. The rabbit model for spinal tuberculosis: An overview. J Orthop Surg (Hong Kong) 2024; 32:10225536241266703. [PMID: 39033332 DOI: 10.1177/10225536241266703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/23/2024] Open
Abstract
Mycobacterium tuberculosis infection has emerged as a global public health issue, predominantly manifesting as pulmonary tuberculosis. Bone and joint tuberculosis, with spinal tuberculosis accounting for approximately 50%, represents a significant form of extrapulmonary tuberculosis. Over the past years, there has been a rise in the incidence of spinal tuberculosis, and research concerning this area has gained significant attention. At present, animal models provide a means to investigate the pathogenesis, drug resistance, and novel treatment approaches for spinal tuberculosis. New Zealand rabbits, possessing a comparable anatomical structure to humans and capable of reproducing typical pathological features of human tuberculosis, are extensively employed in spinal tuberculosis research using animal models. This article comprehensively evaluates the strengths, considerations in strain selection, various modelling approaches, and practical applications of the rabbit model in studying spinal tuberculosis based on pertinent literature to guide fundamental research in this field by providing valuable insights into appropriate animal model selection.
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Affiliation(s)
- Jingwen Jia
- Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, P.R. China
| | - Mingtao Zhang
- Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, P.R. China
| | - Zhenyu Cao
- Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, P.R. China
| | - Xuchang Hu
- Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, P.R. China
| | - Shuanhu Lei
- Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, P.R. China
| | - Yizhi Zhang
- Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, P.R. China
| | - Xuewen Kang
- Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, P.R. China
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2
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Mouse Models for Mycobacterium tuberculosis Pathogenesis: Show and Do Not Tell. Pathogens 2022; 12:pathogens12010049. [PMID: 36678397 PMCID: PMC9865329 DOI: 10.3390/pathogens12010049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 11/29/2022] [Accepted: 12/25/2022] [Indexed: 12/29/2022] Open
Abstract
Science has been taking profit from animal models since the first translational experiments back in ancient Greece. From there, and across all history, several remarkable findings have been obtained using animal models. One of the most popular models, especially for research in infectious diseases, is the mouse. Regarding research in tuberculosis, the mouse has provided useful information about host and bacterial traits related to susceptibility to the infection. The effect of aging, sexual dimorphisms, the route of infection, genetic differences between mice lineages and unbalanced immunity scenarios upon Mycobacterium tuberculosis infection and tuberculosis development has helped, helps and will help biomedical researchers in the design of new tools for diagnosis, treatment and prevention of tuberculosis, despite various discrepancies and the lack of deep study in some areas of these traits.
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3
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Comín J, Madacki J, Rabanaque I, Zúñiga-Antón M, Ibarz D, Cebollada A, Viñuelas J, Torres L, Sahagún J, Klopp C, Gonzalo-Asensio J, Brosch R, Iglesias MJ, Samper S. The MtZ Strain: Molecular Characteristics and Outbreak Investigation of the Most Successful Mycobacterium tuberculosis Strain in Aragon Using Whole-Genome Sequencing. Front Cell Infect Microbiol 2022; 12:887134. [PMID: 35685752 PMCID: PMC9173592 DOI: 10.3389/fcimb.2022.887134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 04/11/2022] [Indexed: 11/13/2022] Open
Abstract
Since 2004, a tuberculosis surveillance protocol has been carried out in Aragon, thereby managing to detect all tuberculosis outbreaks that take place in the community. The largest outbreak was caused by a strain named Mycobacterium tuberculosis Zaragoza (MtZ), causing 242 cases as of 2020. The main objective of this work was to analyze this outbreak and the molecular characteristics of this successful strain that could be related to its greater transmission. To do this, we first applied whole-genome sequencing to 57 of the isolates. This revealed two principal transmission clusters and six subclusters arising from them. The MtZ strain belongs to L4.8 and had eight specific single nucleotide polymorphisms (SNPs) in genes considered to be virulence factors [ptpA, mc3D, mc3F, VapB41, pks15 (two SNPs), virS, and VapC50]. Second, a transcriptomic study was carried out to better understand the multiple IS6110 copies present in its genome. This allowed us to observe three effects of IS6110: the disruption of the gene in which the IS6110 is inserted (desA3), the overexpression of a gene (ppe38), and the absence of transcription of genes (cut1:Rv1765c) due to the recombination of two IS6110 copies. Finally, because of the disruption of ppe38 and ppe71 genes by an IS6110, a study of PE_PGRS secretion was carried out, showing that MtZ secretes these factors in higher amounts than the reference strain, thereby differing from the hypervirulent phenotype described for the Beijing strains. In conclusion, MtZ consists of several SNPs in genes related to virulence, pathogenesis, and survival, as well as other genomic polymorphisms, which may be implicated in its success among our population.
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Affiliation(s)
- Jessica Comín
- Grupo de Genética de Micobacterias, Instituto Aragonés de Ciencias de la Salud, Zaragoza, Spain
| | - Jan Madacki
- Unit for Integrated Mycobacterial Pathogenomics, Institut Pasteur, Université de Paris, CNRS UMR 3525, Paris, France
| | - Isabel Rabanaque
- Departamento de Geografía y Ordenación del Territorio, Universidad de Zaragoza, Zaragoza, Spain.,Instituto Universitario de Investigación en Ciencias Ambientales de Aragón, Zaragoza, Spain.,Fundación Instituto de Investigación Sanitaria (IIS) Aragón, Zaragoza, Spain
| | - María Zúñiga-Antón
- Departamento de Geografía y Ordenación del Territorio, Universidad de Zaragoza, Zaragoza, Spain.,Instituto Universitario de Investigación en Ciencias Ambientales de Aragón, Zaragoza, Spain.,Fundación Instituto de Investigación Sanitaria (IIS) Aragón, Zaragoza, Spain
| | - Daniel Ibarz
- Grupo de Genética de Micobacterias, Facultad de Medicina, Universidad de Zaragoza, Zaragoza, Spain
| | - Alberto Cebollada
- Unidad de Biocomputación, Instituto Aragonés de Ciencias de la Salud, Zaragoza, Spain
| | - Jesús Viñuelas
- Hospital Universitario Miguel Servet, Zaragoza, Spain.,Grupo de Estudio de Infecciones por Micobacterias (GEIM), Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica, Madrid, Spain
| | | | - Juan Sahagún
- Hospital Clínico Universitario Lozano Blesa, Zaragoza, Spain
| | | | - Jesús Gonzalo-Asensio
- Grupo de Genética de Micobacterias, Facultad de Medicina, Universidad de Zaragoza, Zaragoza, Spain
| | - Roland Brosch
- Unit for Integrated Mycobacterial Pathogenomics, Institut Pasteur, Université de Paris, CNRS UMR 3525, Paris, France
| | - María-José Iglesias
- Fundación Instituto de Investigación Sanitaria (IIS) Aragón, Zaragoza, Spain.,Grupo de Genética de Micobacterias, Facultad de Medicina, Universidad de Zaragoza, Zaragoza, Spain.,Centro de Investigación Biomédica en Red (CIBER) de Enfermedades Respiratorias, Madrid, Spain
| | - Sofía Samper
- Grupo de Genética de Micobacterias, Instituto Aragonés de Ciencias de la Salud, Zaragoza, Spain.,Fundación Instituto de Investigación Sanitaria (IIS) Aragón, Zaragoza, Spain.,Centro de Investigación Biomédica en Red (CIBER) de Enfermedades Respiratorias, Madrid, Spain
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4
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Correction: Low Dose Aerosol Fitness at the Innate Phase of Murine Infection Better Predicts Virulence amongst Clinical Strains of Mycobacterium tuberculosis. PLoS One 2019; 14:e0222794. [PMID: 31527887 PMCID: PMC6748405 DOI: 10.1371/journal.pone.0222794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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5
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Folkvardsen DB, Norman A, Andersen ÅB, Rasmussen EM, Lillebaek T, Jelsbak L. A Major Mycobacterium tuberculosis outbreak caused by one specific genotype in a low-incidence country: Exploring gene profile virulence explanations. Sci Rep 2018; 8:11869. [PMID: 30089859 PMCID: PMC6082827 DOI: 10.1038/s41598-018-30363-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 07/10/2018] [Indexed: 12/30/2022] Open
Abstract
Denmark, a tuberculosis low burden country, still experiences significant active Mycobacterium tuberculosis (Mtb) transmission, especially with one specific genotype named Cluster 2/1112-15 (C2), the most prevalent lineage in Scandinavia. In addition to environmental factors, antibiotic resistance, and human genetics, there is increasing evidence that Mtb strain variation plays a role for the outcome of infection and disease. In this study, we explore the reasons for the success of the C2 genotype by analysing strain specific polymorphisms identified through whole genome sequencing of all C2 isolates identified in Denmark between 1992 and 2014 (n = 952), and the demographic distribution of C2. Of 234 non-synonymous (NS) monomorphic SNPs found in C2 in comparison with Mtb reference strain H37Rv, 23 were in genes previously reported to be involved in Mtb virulence. Of these 23 SNPs, three were specific for C2 including a NS mutation in a gene associated with hyper-virulence. We show that the genotype is readily transmitted to different ethnicities and is also found outside Denmark. Our data suggest that strain specific virulence factor variations are important for the success of the C2 genotype. These factors, likely in combination with poor TB control, seem to be the main drivers of C2 success.
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Affiliation(s)
- Dorte Bek Folkvardsen
- International Reference Laboratory of Mycobacteriology, Statens Serum Institut, Copenhagen, Denmark.
| | - Anders Norman
- International Reference Laboratory of Mycobacteriology, Statens Serum Institut, Copenhagen, Denmark
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Åse Bengård Andersen
- Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
- Research Unit for Infectious Diseases, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Erik Michael Rasmussen
- International Reference Laboratory of Mycobacteriology, Statens Serum Institut, Copenhagen, Denmark
| | - Troels Lillebaek
- International Reference Laboratory of Mycobacteriology, Statens Serum Institut, Copenhagen, Denmark
| | - Lars Jelsbak
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
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6
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Chen YY, Lin CW, Huang WF, Chang JR, Su IJ, Hsu CH, Cheng HY, Hsu SC, Dou HY. Recombinant bacille Calmette-Guerin coexpressing Ag85b, CFP10, and interleukin-12 elicits effective protection against Mycobacterium tuberculosis. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2014; 50:90-96. [PMID: 25732698 DOI: 10.1016/j.jmii.2014.11.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 11/11/2014] [Accepted: 11/29/2014] [Indexed: 01/10/2023]
Abstract
BACKGROUND The tuberculosis (TB) pandemic remains a leading cause of human morbidity and mortality, despite widespread use of the only licensed anti-TB vaccine, bacille Calmette-Guerin (BCG). The protective efficacy of BCG in preventing pulmonary TB is highly variable; therefore, an effective new vaccine is urgently required. METHODS In the present study, we assessed the ability of novel recombinant BCG vaccine (rBCG) against Mycobacterium tuberculosis by using modern immunological methods. RESULTS Enzyme-linked immunospot assays demonstrated that the rBCG vaccine, which coexpresses two mycobacterial antigens (Ag85B and CFP10) and human interleukin (IL)-12 (rBCG2) elicits greater interferon-γ (IFN-γ) release in the mouse lung and spleen, compared to the parental BCG. In addition, rBCG2 triggers a Th1-polarized response. Our results also showed that rBCG2 vaccination significantly limits M. tuberculosis H37Rv multiplication in macrophages. The rBCG2 vaccine surprisingly induces significantly higher tumor necrosis factor-α (TNF-α) production by peripheral blood mononuclear cells that were exposed to a nonmycobacterial stimulus, compared to the parental BCG. CONCLUSION In this study, we demonstrated that the novel rBCG2 vaccine may be a promising candidate vaccine against M. tuberculosis infection.
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MESH Headings
- Acyltransferases/administration & dosage
- Acyltransferases/genetics
- Acyltransferases/immunology
- Adjuvants, Immunologic/administration & dosage
- Adjuvants, Immunologic/genetics
- Animals
- Antigens, Bacterial/administration & dosage
- Antigens, Bacterial/genetics
- Antigens, Bacterial/immunology
- Bacterial Proteins/administration & dosage
- Bacterial Proteins/genetics
- Bacterial Proteins/immunology
- Enzyme-Linked Immunospot Assay
- Female
- Humans
- Interferon-gamma/metabolism
- Interleukin-12/administration & dosage
- Interleukin-12/genetics
- Leukocytes, Mononuclear/immunology
- Lung/immunology
- Macrophages/immunology
- Macrophages/microbiology
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mycobacterium bovis/genetics
- Mycobacterium bovis/immunology
- Mycobacterium tuberculosis/growth & development
- Mycobacterium tuberculosis/immunology
- Spleen/immunology
- Th1 Cells/immunology
- Tuberculosis/prevention & control
- Tuberculosis Vaccines/administration & dosage
- Tuberculosis Vaccines/genetics
- Tuberculosis Vaccines/immunology
- Tumor Necrosis Factor-alpha/metabolism
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
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Affiliation(s)
- Yih-Yuan Chen
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Chih-Wei Lin
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Wei-Feng Huang
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Jia-Ru Chang
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Ih-Jen Su
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Chih-Hao Hsu
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Han-Yin Cheng
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Shu-Ching Hsu
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Horng-Yunn Dou
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan.
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7
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Abstract
Nonhuman primates have emerged as an excellent model of human tuberculosis, in large part because they recapitulate the full spectrum of infection outcome and pathology seen in humans. Several variables inherent to the nonhuman primate models of tuberculosis are discussed in this review, including the monkey species, Mycobacterium tuberculosis strains, and routes of infection, all of which can influence the model to be chosen for various studies. New technologies for studying the microbiology, immunology, and pathogenesis of tuberculosis in nonhuman primates have greatly expanded the capabilities of this model for basic and translational studies, including the development and testing of new treatment and prevention strategies for tuberculosis.
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Affiliation(s)
- Charles A Scanga
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
| | - JoAnne L Flynn
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
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8
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Vilaplana C, Cardona PJ. The lack of a big picture in tuberculosis: the clinical point of view, the problems of experimental modeling and immunomodulation. The factors we should consider when designing novel treatment strategies. Front Microbiol 2014; 5:55. [PMID: 24592258 PMCID: PMC3924323 DOI: 10.3389/fmicb.2014.00055] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 01/28/2014] [Indexed: 01/05/2023] Open
Abstract
This short review explores the large gap between clinical issues and basic science, and suggests why tuberculosis research should focus on redirect the immune system and not only on eradicating Mycobacterium tuberculosis bacillus. Along the manuscript, several concepts involved in human tuberculosis are explored in order to understand the big picture, including infection and disease dynamics, animal modeling, liquefaction, inflammation and immunomodulation. Scientists should take into account all these factors in order to answer questions with clinical relevance. Moreover, the inclusion of the concept of a strong inflammatory response being required in order to develop cavitary tuberculosis disease opens a new field for developing new therapeutic and prophylactic tools in which destruction of the bacilli may not necessarily be the final goal.
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Affiliation(s)
- Cristina Vilaplana
- Unitat de Tuberculosi Experimental, Fundació Institut Germans Trias i Pujol, Universitat Autònoma de Barcelona, CIBER Enfermedades Respiratorias Badalona, Spain
| | - Pere-Joan Cardona
- Unitat de Tuberculosi Experimental, Fundació Institut Germans Trias i Pujol, Universitat Autònoma de Barcelona, CIBER Enfermedades Respiratorias Badalona, Spain
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9
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Lutay N, Håkansson G, Alaridah N, Hallgren O, Westergren-Thorsson G, Godaly G. Mycobacteria bypass mucosal NF-kB signalling to induce an epithelial anti-inflammatory IL-22 and IL-10 response. PLoS One 2014; 9:e86466. [PMID: 24489729 PMCID: PMC3904915 DOI: 10.1371/journal.pone.0086466] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 12/13/2013] [Indexed: 01/20/2023] Open
Abstract
The mechanisms by which mycobacteria subvert the inflammatory defence to establish chronic infection remain an unresolved question in the pathogenesis of tuberculosis. Using primary epithelial cells, we have analysed mycobacteria induced epithelial signalling pathways from activation of TLRs to cytokine secretion. Mycobacterium bovis bacilli Calmette-Guerin induced phosphorylation of glycogen synthase kinase (GSK)3 by PI3K-Akt in the signalling pathway downstream of TLR2 and TLR4. Mycobacteria did not suppress NF-κB by activating the peroxisome proliferator-activated receptor γ. Instead the pro-inflammatory NF-κB was bypassed by mycobacteria induced GSK3 inhibition that promoted the anti-inflammatory transcription factor CREB. Mycobacterial infection did not thus induce mucosal pro-inflammatory response as measured by TNFα and IFNγ secretion, but led to an anti-inflammatory IL-10 and IL-22 production. Apart from CREB, MAP3Ks p38 and ERK1/2 activated the transcription factor AP-1 leading to IL-6 production. Interestingly, blocking of TLR4 before infection decreased epithelial IL-6 secretion, but increased the CREB-activated IL-10 production. Our data indicate that mycobacteria suppress epithelial pro-inflammatory production by suppressing NF-κB activation thereby shifting the infection towards an anti-inflammatory state. This balance between the host immune response and the pathogen could determine the outcome of infection.
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Affiliation(s)
- Nataliya Lutay
- Division of Laboratory Medicine, Department of MIG, Lund University, Lund, Sweden
| | - Gisela Håkansson
- Division of Laboratory Medicine, Department of MIG, Lund University, Lund, Sweden
| | - Nader Alaridah
- Division of Laboratory Medicine, Department of MIG, Lund University, Lund, Sweden
| | - Oskar Hallgren
- Division of Clinical Sciences, Department of Respiratory Medicine and Allergology, Lund University, Lund, Sweden
| | - Gunilla Westergren-Thorsson
- Division of Vascular- and Respiratory Research Unit of Lung Biology, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Gabriela Godaly
- Division of Laboratory Medicine, Department of MIG, Lund University, Lund, Sweden
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10
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Global study of IS6110 in a successful Mycobacterium tuberculosis strain: clues for deciphering its behavior and for its rapid detection. J Clin Microbiol 2013; 51:3631-7. [PMID: 23985924 DOI: 10.1128/jcm.00970-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The Mycobacterium tuberculosis insertion sequence IS6110, besides being a very useful tool in molecular epidemiology, seems to have an impact on the biology of bacilli. In the present work, we mapped the 12 points of insertion of IS6110 in the genome of a successful strain named M. tuberculosis Zaragoza (which has been referred to as the MTZ strain). This strain, belonging to principal genetic group 3, caused a large unsuspected tuberculosis outbreak involving 85 patients in Zaragoza, Spain, in 2001 to 2004. The mapping of the points of insertion of IS6110 in the genome of the Zaragoza strain offers clues for a better understanding of the adaptability and virulence of M. tuberculosis. Surprisingly, the presence of one copy of IS6110 was found in Rv2286c, as was recently described for a successful Beijing sublineage. As a result of this analysis, a rapid method for detecting this particular M. tuberculosis strain has been designed.
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11
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Caceres N, Vilaplana C, Prats C, Marzo E, Llopis I, Valls J, Lopez D, Cardona PJ. Evolution and role of corded cell aggregation in Mycobacterium tuberculosis cultures. Tuberculosis (Edinb) 2013; 93:690-8. [PMID: 24011631 DOI: 10.1016/j.tube.2013.08.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 07/17/2013] [Accepted: 08/05/2013] [Indexed: 12/01/2022]
Abstract
The aim of this study was to evaluate the evolution and role of corded cell aggregation in Mycobacterium tuberculosis cultures according to growth time and conditions. Thus, in standard culture using aerated 7H9 Middlebrook broth supplemented with 0.05% Tween 80, a dramatic CFU decrease was observed at the end of the exponential phase. This phase was followed by a stable stationary phase that led to dissociation between the optical density (O.D.) and CFU values, together with the formation of opaque colonies in solid culture. Further analysis revealed that this was due to cording. Scanning electron microscopy showed that cording led to the formation of very stable coiled structures and corded cell aggregations which proved impossible to disrupt by any of the physical means tested. Modulation of cording with a high but non-toxic concentration of Tween 80 led to a slower growth rate, avoidance of a sudden drop-off to the stationary phase, the formation of weaker cording structures and the absence of opaque colonies, together with a lower survival at later time-points. An innovative automated image analysis technique has been devised to characterize the cording process. This analysis has led to important practical consequences for the elaboration of M. tuberculosis inocula and suggests the importance of biofilm formation in survival of the bacilli in the extracellular milieu.
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Affiliation(s)
- Neus Caceres
- Unitat de Tuberculosi Experimental (UTE), Fundació Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Universitat Autònoma de Barcelona, CIBERES, Crtra. de Can Ruti, Camí de les Escoles s/n, Edifici Escoles, 08916 Badalona, Spain
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12
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Håkansson G, Lutay N, Andersson M, Hallgren O, Westergren-Thorsson G, Svensson M, Godaly G. Epithelial G protein-coupled receptor kinases regulate the initial inflammatory response during mycobacterial infection. Immunobiology 2012; 218:984-94. [PMID: 23312955 DOI: 10.1016/j.imbio.2012.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2012] [Revised: 11/12/2012] [Accepted: 11/14/2012] [Indexed: 01/04/2023]
Abstract
The interaction between mycobacteria and epithelium is unexplored, but may determine the outcome of the infection. We have analyzed the role of two G protein-coupled receptors, CXCR1 and CXCR2 that are important regulators of many pulmonary diseases. We found that mycobacteria significantly increased the expression of both CXCR1 and CXCR2 on alveolar epithelial cells and both receptors were found to be important for neutrophil diapedesis across primary endothelial cells towards infected mucosa. Mycobacteria, lipoarabinomannan or 19-kDa glycolipoprotein up-regulated the inhibitory G protein-coupled receptor kinase (GRK)2, while GRK3 was less affected. Mycobacteria-induced GRK2 up-regulation decreased chemokine transcription and secretion thereby affecting the neutrophil recruitment to infected mucosa. These events were completely abolished by blocking these receptors prior to infection as the blocking increased epithelial immune responses. We have identified novel interactions occurring in the initial phase of mycobacterial infections by which mycobacterial manipulate epithelial inflammatory responses.
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Affiliation(s)
- Gisela Håkansson
- Department of MIG, Division of Laboratory Medicine, Lund University, Lund, Sweden
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