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Asadian M, Hassanzadeh SM, Safarchi A, Douraghi M. The effect of in vitro consecutive passages and culture medium on the genetic variations in BCG Pasteur 1173P2 vaccine. PLoS One 2023; 18:e0280294. [PMID: 36689397 PMCID: PMC9870133 DOI: 10.1371/journal.pone.0280294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/24/2022] [Indexed: 01/24/2023] Open
Abstract
Since the introduction of the Bacillus Calmette-Guérin (BCG) vaccine, the genomes of vaccine strains have undergone variations due to repeated passages in different laboratories and vaccine production facilities. Genetic variations have been considered as one of the effective factors in the BCG variable protective efficacy. Consecutive subcultures have been shown to play an essential role in causing genetic variations in several microorganisms, including Mycobacterium bovis BCG. Therefore, the world health organization (WHO) recommendation to limit the passages of master seed lot in the BCG vaccine production should be considered. Besides, the role of other external variables such as quality of the raw ingredients of the culture media, the type of the culture medium and the cultivation methods in the vaccine production has been poorly studied. Here, the effect of passages and culture medium on genetic variations in a BCG seed lot was investigated during a year. The findings of this study revealed a total of 19 variants compared to seed lot while the passages were more than the number recommended by WHO. The first culture of seed lot in the Sauton broth and Middlebrook 7H9 media, and the last subculture in Sauton broth had the least and the most variants, respectively. The observation of the higher number of variants in the last cultures on Sauton broth and Middlebrook 7H9 in comparison to the first and the middle cultures may indicate the effect of passages on the genetic variations in BCG. Additionally, more variants in BCG grown in the Sauton broth do not necessarily represent the greater ability of this medium to cause genetic mutations. For a better conclusion, it is required to examine the medium components as independent variables.
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Affiliation(s)
- Mahla Asadian
- Division of Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Azadeh Safarchi
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Masoumeh Douraghi
- Division of Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
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2
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Malave Sanchez M, Saleeb P, Kottilil S, Mathur P. Oral Polio Vaccine to Protect Against COVID-19: Out of the Box Strategies? Open Forum Infect Dis 2021; 8:ofab367. [PMID: 34381846 PMCID: PMC8344522 DOI: 10.1093/ofid/ofab367] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 07/08/2021] [Indexed: 12/14/2022] Open
Abstract
The global coronavirus disease 2019 pandemic has raised significant concerns of developing rapid, broad strategies to protect the vulnerable population and prevent morbidity and mortality. However, even with an aggressive approach, controlling the pandemic has been challenging, with concerns of emerging variants that likely escape vaccines, nonadherence of social distancing/preventive measures by the public, and challenges in rapid implementation of a global vaccination program that involves mass production, distribution, and execution. In this review, we revisit the utilization of attenuated vaccinations, such as the oral polio vaccine, which are safe, easy to administer, and likely provide cross-protection against respiratory pathogens. We discuss the rationale and data supporting its use and detail description of available vaccines that could be repurposed for curtailing the pandemic.
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Affiliation(s)
- Melanie Malave Sanchez
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Paul Saleeb
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Shyam Kottilil
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Poonam Mathur
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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3
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Pascoe J, Hendon-Dunn CL, Birch CP, Williams GA, Chambers MA, Bacon J. Optimisation of Mycobacterium bovis BCG Fermentation and Storage Survival. Pharmaceutics 2020; 12:pharmaceutics12090900. [PMID: 32971826 PMCID: PMC7558299 DOI: 10.3390/pharmaceutics12090900] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/02/2020] [Accepted: 09/10/2020] [Indexed: 11/16/2022] Open
Abstract
Mycobacterium bovis Bacillus Calmette–Guérin (M. bovis BCG) was generated over a century ago for protection against Mycobacterium tuberculosis (Mtb) and is one the oldest vaccines still in use. The BCG vaccine is currently produced using a pellicle growth method, which is a complex and lengthy process that has been challenging to standardise. Fermentation for BCG vaccine production would reduce the complexity associated with pellicle growth and increase batch to batch reproducibility. This more standardised growth lends itself to quantification of the total number of bacilli in the BCG vaccine by alternative approaches, such as flow cytometry, which can also provide information about the metabolic status of the bacterial population. The aim of the work reported here was to determine which batch fermentation conditions and storage conditions give the most favourable outcomes in terms of the yield and stability of live M. bovis BCG Danish bacilli. We compared different media and assessed growth over time in culture, using total viable counts, total bacterial counts, and turbidity throughout culture. We applied fluorescent viability dyes and flow cytometry to measure real-time within-culture viability. Culture samples were stored in different cryoprotectants at different temperatures to assess the effect of these combined conditions on bacterial titres. Roisin’s minimal medium and Middlebrook 7H9 medium gave comparable, high titres in fermenters. Flow cytometry proved to be a useful tool for enumeration of total bacterial counts and in the assessment of within-culture cell viability and cell death. Of the cryoprotectants evaluated, 5% (v/v) DMSO showed the most significant positive effect on survival and reduced the negative effects of low temperature storage on M. bovis BCG Danish viability. In conclusion, we have shown a reproducible, more standardised approach for the production, evaluation, and storage of high titre, viable, BCG vaccine.
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Affiliation(s)
- Jordan Pascoe
- TB Research Group, Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire SP4 0JG, UK; (J.P.); (C.L.H.-D.)
| | - Charlotte L. Hendon-Dunn
- TB Research Group, Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire SP4 0JG, UK; (J.P.); (C.L.H.-D.)
| | - Colin P.D. Birch
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK;
| | - Gareth A. Williams
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (G.A.W.); (M.A.C.)
| | - Mark A. Chambers
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (G.A.W.); (M.A.C.)
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK
| | - Joanna Bacon
- TB Research Group, Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire SP4 0JG, UK; (J.P.); (C.L.H.-D.)
- Correspondence:
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4
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Lesellier S, Birch CPD, Davé D, Dalley D, Gowtage S, Palmer S, McKenna C, Williams GA, Ashford R, Weyer U, Beatham S, Coats J, Nunez A, Sanchez-Cordon P, Spiropoulos J, Powell S, Sawyer J, Pascoe J, Hendon-Dunn C, Bacon J, Chambers MA. Bioreactor-Grown Bacillus of Calmette and Guérin (BCG) Vaccine Protects Badgers against Virulent Mycobacterium bovis When Administered Orally: Identifying Limitations in Baited Vaccine Delivery. Pharmaceutics 2020; 12:pharmaceutics12080782. [PMID: 32824778 PMCID: PMC7463497 DOI: 10.3390/pharmaceutics12080782] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/13/2020] [Accepted: 08/15/2020] [Indexed: 01/23/2023] Open
Abstract
Bovine tuberculosis (TB) in Great Britain adversely affects animal health and welfare and is a cause of considerable economic loss. The situation is exacerbated by European badgers (Meles meles) acting as a wildlife source of recurrent Mycobacterium bovis infection to cattle. Vaccination of badgers against TB is a possible means to reduce and control bovine TB. The delivery of vaccine in oral bait holds the best prospect for vaccinating badgers over a wide geographical area. There are practical limitations over the volume and concentration of Bacillus of Calmette and Guérin (BCG) that can be prepared for inclusion in bait. The production of BCG in a bioreactor may overcome these issues. We evaluated the efficacy of oral, bioreactor-grown BCG against experimental TB in badgers. We demonstrated repeatable protection through the direct administration of at least 2.0 × 108 colony forming units of BCG to the oral cavity, whereas vaccination via voluntary consumption of bait containing the same preparation of BCG did not result in demonstrable protection at the group-level, although a minority of badgers consuming bait showed immunological responses and protection after challenge equivalent to badgers receiving oral vaccine by direct administration. The need to deliver oral BCG in the context of a palatable and environmentally robust bait appears to introduce such variation in BCG delivery to sites of immune induction in the badger as to render experimental studies variable and inconsistent.
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Affiliation(s)
- Sandrine Lesellier
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (S.L.); (D.D.); (D.D.); (S.G.); (S.P.); (C.M.); (G.A.W.); (R.A.); (J.S.)
- Laboratoire de la Rage et de la Faune Sauvage de Nancy (LRFSN), Technopole Agricole et Vétérinaire, Domaine de Pixérécourt-Bât. H., CS 40009-54220 Malzéville, France
| | - Colin P. D. Birch
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK;
| | - Dipesh Davé
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (S.L.); (D.D.); (D.D.); (S.G.); (S.P.); (C.M.); (G.A.W.); (R.A.); (J.S.)
| | - Deanna Dalley
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (S.L.); (D.D.); (D.D.); (S.G.); (S.P.); (C.M.); (G.A.W.); (R.A.); (J.S.)
| | - Sonya Gowtage
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (S.L.); (D.D.); (D.D.); (S.G.); (S.P.); (C.M.); (G.A.W.); (R.A.); (J.S.)
| | - Simonette Palmer
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (S.L.); (D.D.); (D.D.); (S.G.); (S.P.); (C.M.); (G.A.W.); (R.A.); (J.S.)
| | - Claire McKenna
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (S.L.); (D.D.); (D.D.); (S.G.); (S.P.); (C.M.); (G.A.W.); (R.A.); (J.S.)
| | - Gareth A. Williams
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (S.L.); (D.D.); (D.D.); (S.G.); (S.P.); (C.M.); (G.A.W.); (R.A.); (J.S.)
| | - Roland Ashford
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (S.L.); (D.D.); (D.D.); (S.G.); (S.P.); (C.M.); (G.A.W.); (R.A.); (J.S.)
| | - Ute Weyer
- Animal Services Unit, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK;
| | - Sarah Beatham
- Animal and Plant Health Agency, Sand Hutton Campus, York, North Yorkshire YO41 1LZ, UK; (S.B.); (J.C.)
| | - Julia Coats
- Animal and Plant Health Agency, Sand Hutton Campus, York, North Yorkshire YO41 1LZ, UK; (S.B.); (J.C.)
| | - Alex Nunez
- Department of Pathology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (A.N.); (P.S.-C.); (J.S.)
| | - Pedro Sanchez-Cordon
- Department of Pathology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (A.N.); (P.S.-C.); (J.S.)
| | - John Spiropoulos
- Department of Pathology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (A.N.); (P.S.-C.); (J.S.)
| | - Stephen Powell
- Data Systems Group, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK;
| | - Jason Sawyer
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (S.L.); (D.D.); (D.D.); (S.G.); (S.P.); (C.M.); (G.A.W.); (R.A.); (J.S.)
| | - Jordan Pascoe
- Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire SP4 0JG, UK; (J.P.); (C.H.-D.); (J.B.)
| | - Charlotte Hendon-Dunn
- Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire SP4 0JG, UK; (J.P.); (C.H.-D.); (J.B.)
| | - Joanna Bacon
- Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire SP4 0JG, UK; (J.P.); (C.H.-D.); (J.B.)
| | - Mark A. Chambers
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (S.L.); (D.D.); (D.D.); (S.G.); (S.P.); (C.M.); (G.A.W.); (R.A.); (J.S.)
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK
- Correspondence:
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5
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Guallar-Garrido S, Campo-Pérez V, Sánchez-Chardi A, Luquin M, Julián E. Each Mycobacterium Requires a Specific Culture Medium Composition for Triggering an Optimized Immunomodulatory and Antitumoral Effect. Microorganisms 2020; 8:microorganisms8050734. [PMID: 32423030 PMCID: PMC7284523 DOI: 10.3390/microorganisms8050734] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/01/2020] [Accepted: 05/13/2020] [Indexed: 11/30/2022] Open
Abstract
Mycobacterium bovis bacillus Calmette-Guérin (BCG) remains the first treatment option for non-muscle-invasive bladder cancer (BC) patients. In research laboratories, M. bovis BCG is mainly grown in commercially available media supplemented with animal-derived agents that favor its growth, while biomass production for patient treatment is performed in Sauton medium which lacks animal-derived components. However, there is not a standardized formulation of Sauton medium, which could affect mycobacterial characteristics. Here, the impact of culture composition on the immunomodulatory and antitumor capacity of M. bovis BCG and Mycolicibacterium brumae, recently described as efficacious for BC treatment, has been addressed. Both mycobacteria grown in Middlebrook and different Sauton formulations, differing in the source of nitrogen and amount of carbon source, were studied. Our results indicate the relevance of culture medium composition on the antitumor effect triggered by mycobacteria, indicating that the most productive culture medium is not necessarily the formulation that provides the most favorable immunomodulatory profile and the highest capacity to inhibit BC cell growth. Strikingly, each mycobacterial species requires a specific culture medium composition to provide the best profile as an immunotherapeutic agent for BC treatment. Our results highlight the relevance of meticulousness in mycobacteria production, providing insight into the application of these bacteria in BC research.
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Affiliation(s)
- Sandra Guallar-Garrido
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain; (S.G.-G.); (V.C.-P.); (M.L.)
| | - Víctor Campo-Pérez
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain; (S.G.-G.); (V.C.-P.); (M.L.)
- Bacterial Infections and Antimicrobial Therapies group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), 08028 Barcelona, Spain
| | - Alejandro Sánchez-Chardi
- Servei de Microscòpia, Universitat Autònoma de Barcelona, 08193 Barcelona, Spain;
- Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Marina Luquin
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain; (S.G.-G.); (V.C.-P.); (M.L.)
| | - Esther Julián
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain; (S.G.-G.); (V.C.-P.); (M.L.)
- Correspondence: ; Tel.: +34-93-5814870
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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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7
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Lefrancois LH, Bodier CC, Lecher S, Gilbert FB, Cochard T, Harichaux G, Labas V, Teixeira-Gomes AP, Raze D, Locht C, Biet F. Purification of native HBHA from Mycobacterium avium subsp. paratuberculosis. BMC Res Notes 2013; 6:55. [PMID: 23390963 PMCID: PMC3586368 DOI: 10.1186/1756-0500-6-55] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 01/30/2013] [Indexed: 11/10/2022] Open
Abstract
Background Paratuberculosis remains today a major global problem in animal health, especially for dairy cattle. However, the diagnosis of its etiologic agent, Mycobacterium avium subsp. paratuberculosis (Map), still lacks sensitivity because of the lack of available antigens. Little is known about the virulence factors for this pathogen. In this study we have developed a method to produce and purify the heparin-binding hemagglutinin (HBHA), a major adhesin of Mycobacteria, from a culture of Map. Findings For this extremely slow-growing Mycobacterium, a culture was established in a 3-liter bioreactor. Using the bioreactor the amount of the Map biomass was increased 5-fold compared to a classical culture in flasks. The map-HBHA was purified from a Map lysate by heparin-Sepharose chromatography on HiTrap columns. Binding of map-HBHA onto heparin-Sepharose can be reduced in the presence of salt. Consequently, all steps of sample preparation and column equilibration were carried out in 20 mM Tris–HCl (pH 7.2). The map-HBHA was eluted by a linear NaCl gradient. High resolution mass spectrometry analyses revealed that the native form of map-HBHA has posttranslational modifications, including the removal of the initiation methionine, acetylation of the alanine residue at the N-terminal extremity and the presence of methylated lysines in the C-terminal domain of the protein. Conclusions An optimized culture of Map in a bioreactor was established to purify the native map-HBHA from a Map lysate by heparin-Sepharose chromatography. The availability of this antigen offers the possibility to study the structure of the protein and to examine its role in pathogenicity, in particular to better understand the specific interactions of Map with the intestinal tissue. The map-HBHA obtained in its native immunogenic form may also be useful to improve the diagnostic test, especially for the development of a new T-cell-based interferon gamma release assays.
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Affiliation(s)
- Louise H Lefrancois
- INRA, UMR ISP 1282 Infectiologie et Santé Publique, Nouzilly F-37380, France.
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Low dose aerosol fitness at the innate phase of murine infection better predicts virulence amongst clinical strains of Mycobacterium tuberculosis. PLoS One 2012; 7:e29010. [PMID: 22235258 PMCID: PMC3250398 DOI: 10.1371/journal.pone.0029010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Accepted: 11/18/2011] [Indexed: 01/06/2023] Open
Abstract
Background Evaluation of a quick and easy model to determine the intrinsic ability of clinical strains to generate active TB has been set by assuming that this is linked to the fitness of Mycobacterium tuberculosis strain at the innate phase of the infection. Thus, the higher the bacillary load, the greater the possibility of inducting liquefaction, and thus active TB, once the adaptive response is set. Methodology/Principal Findings The virulence of seven clinical Mycobacterium tuberculosis strains isolated in Spain was tested by determining the bacillary concentration in the spleen and lung of mice at weeks 0, 1 and 2 after intravenous (IV) inoculation of 104 CFU, and by determining the growth in vitro until the stationary phase had been reached. Cord distribution automated analysis showed two clear patterns related to the high and low fitness in the lung after IV infection. This pattern was not seen in the in vitro fitness tests, which clearly favored the reference strain (H37Rv). Subsequent determination using a more physiological low-dose aerosol (AER) inoculation with 102 CFU showed a third pattern in which the three best values coincided with the highest dissemination capacity according to epidemiological data. Conclusions/Significance The fitness obtained after low dose aerosol administration in the presence of the innate immune response is the most predictive factor for determining the virulence of clinical strains. This gives support to a mechanism of the induction of active TB derived from the dynamic hypothesis of latent tuberculosis infection.
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An oral Mycobacterium bovis BCG vaccine for wildlife produced in the absence of animal-derived reagents. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2009; 16:1378-80. [PMID: 19571109 DOI: 10.1128/cvi.00198-09] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cultures of Mycobacterium bovis BCG, comprising predominantly single-cell bacilli, were prepared in broth without animal-derived reagents. When formulated into a vegetable-derived lipid matrix, the vaccine was stable in vitro and was immunogenic in vivo upon feeding it to mice. This formulation could be useful for oral vaccination of wildlife against tuberculosis, where concern over transmissible prions may preclude the field use of vaccines containing animal products.
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10
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Cell Aggregation in Cultures of Micrococcus luteus, Studied by Dynamic Light Scattering. APPL BIOCHEM MICRO+ 2005. [DOI: 10.1007/s10438-005-0103-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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11
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Beste DJV, Peters J, Hooper T, Avignone-Rossa C, Bushell ME, McFadden J. Compiling a molecular inventory for Mycobacterium bovis BCG at two growth rates: evidence for growth rate-mediated regulation of ribosome biosynthesis and lipid metabolism. J Bacteriol 2005; 187:1677-84. [PMID: 15716438 PMCID: PMC1064002 DOI: 10.1128/jb.187.5.1677-1684.2005] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2004] [Accepted: 11/29/2004] [Indexed: 11/20/2022] Open
Abstract
An experimental system of Mycobacterium tuberculosis growth in a carbon-limited chemostat has been established by the use of Mycobacterium bovis BCG as a model organism. For this model, carbon-limited chemostats with low concentrations of glycerol were used to simulate possible growth rates during different stages of tuberculosis. A doubling time of 23 h (D = 0.03 h(-1)) was adopted to represent cells during the acute phase of infection, whereas a lower dilution rate equivalent to a doubling time of 69 h (D = 0.01 h(-1)) was used to model mycobacterial persistence. This chemostat model allowed the specific response of the mycobacterial cell to carbon limitation at different growth rates to be elucidated. The macromolecular (RNA, DNA, carbohydrate, and lipid) and elemental (C, H, and N) compositions of the biomass were determined for steady-state cultures, revealing that carbohydrates and lipids comprised more than half of the dry mass of the BCG cell, with only a quarter of the dry weight consisting of protein and RNA. Consistent with studies of other bacteria, the specific growth rate impacts on the macromolecular content of BCG and the proportions of lipid, RNA, and protein increased significantly with the growth rate. The correlation of RNA content with the growth rate indicates that ribosome production in carbon-limited M. bovis BCG cells is subject to growth rate-dependent control. The results also clearly show that the proportion of lipids in the mycobacterial cell is very sensitive to changes in the growth rate, probably reflecting changes in the amounts of storage lipids. Finally, this study demonstrates the utility of the chemostat model of mycobacterial growth for functional genomic, physiology, and systems biology studies.
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Affiliation(s)
- D J V Beste
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom
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12
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Chambers MA, Wright DC, Brisker J, Williams A, Hatch G, Gavier-Widén D, Hall G, Marsh PD, Glyn Hewinson R. A single dose of killed Mycobacterium bovis BCG in a novel class of adjuvant (Novasome™) protects guinea pigs from lethal tuberculosis. Vaccine 2004; 22:1063-71. [PMID: 15161084 DOI: 10.1016/j.vaccine.2003.05.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The only vaccine currently available for the prevention of tuberculosis in man is a live attenuated vaccine, bacille Calmette-Guerin (BCG), derived from Mycobacterium bovis. Concerns over the lack of the universal efficacy and safety of BCG have resulted in efforts to develop a new generation of TB vaccines. Historically, killed whole-cell preparations of mycobacteria have been ineffective vaccines. We revisited the potential of killed whole-cell vaccines by comparing their efficacy with live BCG Pasteur in a guinea pig challenge model. BCG Pasteur was inactivated with a low concentration of formalin and showed to be non-viable in culture or severe combined immunodeficient mice. Formalin-inactivated BCG was mixed with non-phospholipid liposome adjuvants (Novasomes) and administered to guinea pigs as a single subcutaneous inoculation. All formulations were well tolerated and one conferred a significant survival advantage against lethal aerogenic challenge with M. bovis.
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Affiliation(s)
- Mark A Chambers
- TB Research Group, Veterinary Laboratories Agency Weybridge, Department of Statutory and Exotic Bacteria, New Haw, Addlestone, Surrey KT15 3NB, UK.
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