%0 Journal Article
%T Role of P27 -P55 operon from Mycobacterium tuberculosis in the resistance to toxic compounds
%A Mar¨ªa V Bianco
%A Federico C Blanco
%A Bel¨¦n Imperiale
%A Marina A Forrellad
%A Roxana V Rocha
%A Laura I Klepp
%A Angel A Cataldi
%A Nora Morcillo
%A Fabiana Bigi
%J BMC Infectious Diseases
%D 2011
%I BioMed Central
%R 10.1186/1471-2334-11-195
%X In order to test the susceptibility of a mutant of M. tuberculosis H37Rv in the P27-P55 operon to malachite green, sodium dodecyl sulfate, ethidium bromide, and first-line antituberculosis drugs, this strain together with the wild type strain and a set of complemented strains were cultivated in the presence and in the absence of these drugs. In addition, the malachite green decolorization rate of each strain was obtained from decolorization curves of malachite green in PBS containing bacterial suspensions.The mutant strain decolorized malachite green faster than the wild type strain and was hypersensitive to both malachite green and ethidium bromide, and more susceptible to the first-line antituberculosis drugs: isoniazid and ethambutol. The pump inhibitor reserpine reversed M. tuberculosis resistance to ethidium bromide. These results suggest that P27-P55 functions through an efflux-pump like mechanism. In addition, deletion of the P27-P55 operon made M. tuberculosis susceptible to sodium dodecyl sulfate, suggesting that the lack of both proteins causes alterations in the cell wall permeability of the bacterium. Importantly, both P27 and P55 are required to restore the wild type phenotypes in the mutant.The results clearly indicate that P27 and P55 are functionally connected in processes that involve the preservation of the cell wall and the transport of toxic compounds away from the cells.Infection by Mycobacterium tuberculosis is a major health problem worldwide [1]. Pathogenic mycobacterial species show remarkable ability to survive in the diverse conditions encountered during the infection process [2]. However, even after decades of investigation, the knowledge about the mycobacterial pathogenesis remains insufficient. The identification of the genes associated with the multiplication and survival of bacilli in the host has provided a framework to study M. tuberculosis virulence [3]. However, little is still known about the role of the encoded products in the i
%K Mycobacterium tuberculosis
%K lprG
%K P55
%K P27
%U http://www.biomedcentral.com/1471-2334/11/195