Porins limit the intracellular persistence of Mycobacterium smegmatis.
The genus Mycobacterium comprises highly pathogenic as well as opportunistic or apathogenic species exhibiting a great variability with respect to their ability to persist or multiply within monocytic host cells. The impact of the permeability of the mycobacterial outer membrane on intracellular persistence was studied. For this purpose, a Mycobacterium smegmatis mutant with a deletion of the major porin gene mspA and a second mutant lacking mspA and the homologous porin gene mspC were used. Deletion of mspA together with mspC significantly enhanced intracellular persistence in murine bone marrow macrophages, the mouse macrophage cell line J774A.1 and Acanthamoeba castellanii. Complementation of mspA in the porin mutant strains resulted in restoration of the wild-type phenotype with respect to intracellular persistence. This is the first report to show that the deletion of porins of mycobacteria results in improved persistence in eukaryotic cells, demonstrating that the intracellular persistence of M. smegmatis depends upon the permeability of the outer membrane.
Robert Koch-Institut, Nordufer 20, 13353 Berlin, Germany.
Soroush
S
Sharbati-Tehrani
Lehrstuhl für Mikrobiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, 91058 Erlangen, Germany.
Joachim
J
Stephan
Robert Koch-Institut, Nordufer 20, 13353 Berlin, Germany.
Gudrun
G
Holland
Robert Koch-Institut, Nordufer 20, 13353 Berlin, Germany.
Bernd
B
Appel
Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.|Lehrstuhl für Mikrobiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, 91058 Erlangen, Germany.
Michael
M
Niederweis
Robert Koch-Institut, Nordufer 20, 13353 Berlin, Germany.
Astrid
A
Lewin
D048248:Acanthamoeba castellanii / Q000166:cytology; D002460:Cell Line; D002463:Cell Membrane Permeability; D002473:Cell Wall / Q000378:metabolism*; D020102:Mycobacterium smegmatis / Q000235:genetics / Q000502:physiology*; D018272:Porins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
C434272:MspC protein, Mycobacterium smegmatis; D018272:Porins; C121838:mspA protein, Mycobacterium smegmatis