Format

Send to:

Choose Destination
See comment in PubMed Commons below
Infect Immun. 1996 May;64(5):1794-9.

Leucine auxotrophy restricts growth of Mycobacterium bovis BCG in macrophages.

Author information

  • 1Department of Microbiology and Immunology, Howard Hughes Medical Institute, Albert Einstein College of Medicine, Yeshiva University, Bronx, New York 10461, USA.

Abstract

The ability of slow-growing mycobacteria to replicate within host mononuclear phagocytes is thought to be central to the pathogenesis of mycobacterial infection. However, because of the lack of a mycobacterial mutant defective for intracellular replication, it has not been possible to test this hypothesis directly. Previously, we showed that a BCG leucine auxotroph with a transposon disruption of the leuD gene is unable to grow in mice. Here we demonstrate that this mutant is also incapable of replicating within cultured macrophages in vitro. Complementation of the leuD mutation with the leuCD genes of Escherichia coli restored wild-type levels of growth in macrophages, establishing that the defect for intracellular replication was due to leucine auxotrophy per se and not to a polar effect of the transposon insertion on an adjacent gene. These results suggest that the inability of the leucine auxotroph to grow in mice was due to its sequestration, after phagocytosis, in an intracellular compartment from which it could not obtain leucine.

PMID:
8613393
[PubMed - indexed for MEDLINE]
PMCID:
PMC173994
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk