Koch's bacillus - a look at the first isolate of Mycobacterium tuberculosis from a modern perspective.
Using molecular methods the authors have studied mycobacterial DNA taken from a 19th century victim of tuberculosis. This was the case from which Robert Koch first isolated and cultured the organism responsible for tuberculosis. The mycobacteria were preserved within five glass culture tubes as abundant bacterial colonies on slopes of a gelatinous culture medium of unknown composition. Originally presented by Koch to surgical laryngologist Walter Jobson Horne in London in 1901, the relic has, since 1983, been in the care of the Royal College of Surgeons of England. Light and electron microscopy established the presence of acid-fast mycobacteria but showed that morphological preservation was generally poor. Eleven different genomic loci were successfully amplified by PCR. This series of experiments confirmed that the organisms were indeed Mycobacterium tuberculosis and further showed that the original strain was in evolutionary terms similar to 'modern' isolates, having undergone the TB D1 deletion. Attempts to determine the genotypic group of the isolate were only partially successful, due in part to the degraded nature of the DNA and possibly also to a truncation in the katG gene, which formed part of the classification scheme. Spoligotyping resulted in amplification of DR spacers consistent with M. tuberculosis but with discrepancies between independent extracts, stressing the limitations of this typing method when applied to poorly preserved material.
Centre for Molecular Microbiology and Infection, Flowers Building, Armstrong Road, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
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Taylor
Centre for Molecular Microbiology and Infection, Flowers Building, Armstrong Road, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
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Stewart
Museums of The Royal College of Surgeons of England, 35-43 Lincoln's Inn Fields, London WC2A 3PE, UK.
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Cooke
Museums of The Royal College of Surgeons of England, 35-43 Lincoln's Inn Fields, London WC2A 3PE, UK.
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Chaplin
Department of Histopathology, Imperial College London, St Mary's Campus, London W2 1PG, UK.
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Ladva
Museums of The Royal College of Surgeons of England, 35-43 Lincoln's Inn Fields, London WC2A 3PE, UK.
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Kirkup
TB Diagnostic Department, Veterinary Laboratory Agency, Addlestone, New Haw, Weybridge, Surrey KT15 3NB, UK.
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Palmer
Centre for Molecular Microbiology and Infection, Flowers Building, Armstrong Road, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
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Young
D001432:Bacteriology / Q000266:history* / Q000639:trends; D001483:Base Sequence; D017931:DNA Primers; D004269:DNA, Bacterial / Q000302:isolation & purification; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000648:ultrastructure; D016133:Polymerase Chain Reaction / Q000379:methods; D014376:Tuberculosis / Q000266:history
D017931:DNA Primers; D004269:DNA, Bacterial