Mycobacterium tuberculosis cpsA is a master regulator in adaptation to the macrophage phagosome

Abstract number: P1320

Alzohairy M., Graham J.E.

Mycobacterium tuberculosis maintains a relatively large genetic repertoire for adaptation to a variety of different environments encountered during typical respiratory infections. Adaptation to these in vivo niches is critical in maintain and sustaining infection. An environment of central relevance in all infections, and among the first encountered, is that within the phagosomes of human macrophages. Global analyses of bacterial RNAs produced in response to phagocytosis produced a list of candidates including that predicted to encode the transcriptional regulator CpsA. We investigated the contribution of cpsA regulated gene expression to M. tuberculosis pathogenesis and identified a large regulaon consisting of about 30 genes whose transcript levels were increased by increased cpsA expression. These included transcriptional regulators sigE, sigB, Rv0195, and indicating a regulatory cascade initiated by cpsA expression following phagocytosis. Bacterial mutants unable to express cpsA were impaired in intracellular growth and this defect was complemented by restoration of cpsA. We provide the initial characterisation of a key transactional activator initiating a global regulatory response allowing M. tuberculosis to colonise its normal ecological niches in the macrophages phagosome.

Session Details

Date: 16/05/2009
Time: 00:00-00:00
Session name: 19th European Congress of Clinical Microbiology and Infectious Diseases
Location: Helsinki, Finland, 16 - 19 May 2009
Presentation type:
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