Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1993-6-21
pubmed:abstractText
The kinetics of growth of two virulent strains of mycobacteria (M. tuberculosis Erdman and M. tuberculosis H37Rv) and two attenuated strains (M. tuberculosis H37Ra and M. bovis Bacillus Calmette-Guerin [BCG]) were studied in the lungs, livers, spleens, and kidneys of severe combined immunodeficient (SCID) mice and of their coisogenic CB-17 immunocompetent counterparts. It was found, in keeping with the findings of earlier investigators (Pierce, C. H., R. J. Dubos, and W. B. Schaefer. 1953. J. Exp. Med. 97:189.), that in immunocompetent mice, virulent organisms grew progressively only in the lungs, whereas the growth of attenuated organisms was controlled in all organs. In SCID mice, in contrast, virulent mycobacteria grew rapidly and progressively in all organs, as did BCG, although at a slower rate. However, H37Ra failed to grow progressively in any organs of SCID mice, unless the mice were treated with hydrocortisone. In fact, hydrocortisone treatment enabled virulent, as well as attenuated, organisms to grow strikingly more rapidly in all organs of SCID mice and in all organs of CB-17 mice. A histological study showed that in SCID mice, multiplication of mycobacteria in the liver occurs in the cytoplasm of macrophages in granulomas and presumably in macrophages in other organs. It is suggested, therefore, that the macrophages of SCID mice possess a glucocorticoid-sensitive mycobacterial mechanism that prevents virulent and avirulent mycobacteria from expressing their true minimal doubling times. In the absence of this mechanism in the lungs of hydrocortisone-treated SCID mice, the doubling times of Erdman, H37Rv, BCG, and H37Ra were 17.7, 17.4, 44.6, and 98.6 h, respectively. The possible importance of a rapid multiplication rate for mycobacterial virulence is discussed.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-13022873, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-1354243, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-14273671, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-14462520, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-1870559, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-1890984, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-2117637, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-2129316, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-2492259, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-2494425, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-2516995, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-3114383, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-3263722, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-3932471, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-591061, http://linkedlifedata.com/resource/pubmed/commentcorrection/8496688-7056582
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-1007
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
177
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1723-33
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Mycobacterial virulence. Virulent strains of Mycobacteria tuberculosis have faster in vivo doubling times and are better equipped to resist growth-inhibiting functions of macrophages in the presence and absence of specific immunity.
pubmed:affiliation
Trudeau Institute, Inc., Saranac Lake, New York 12983.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't