Acidic pH induced STM1485 gene is essential for intracellular replication of Salmonella

Allam, Uday Sankar and Krishna, M. Gopala and Sen, Minakshi and Thomas, Rony and Lahiri, Amit and Gnanadhas, Divya Prakash and Chakravortty, Dipshikha (2012) Acidic pH induced STM1485 gene is essential for intracellular replication of Salmonella. In: VIRULENCE, 3 (2). pp. 122-135.

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Abstract

During the course of infection, Salmonella has to face several potentially lethal environmental conditions, one such being acidic pH. The ability to sense and respond to the acidic pH is crucial for the survival and replication of Salmonella. The physiological role of one gene (STM1485) involved in this response, which is upregulated inside the host cells (by 90- to 113-fold) is functionally characterized in Salmonella pathogenesis. In vitro, the DSTM1485 neither exhibited any growth defect at pH 4.5 nor any difference in the acid tolerance response. The DSTM1485 was compromised in its capacity to proliferate inside the host cells and complementation with STM1485 gene restored its virulence. We further demonstrate that the surface translocation of Salmonella pathogenicity island-2 (SPI-2) encoded translocon proteins, SseB and SseD were reduced in the DSTM1485. The increase in co-localization of this mutant with lysosomes was also observed. In addition, the DSTM1485 displayed significantly reduced competitive indices (CI) in spleen, liver and mesenteric lymph nodes in murine typhoid model when infected by intra-gastric route. Based on these results, we conclude that the acidic pH induced STM1485 gene is essential for intracellular replication of Salmonella.

Item Type:	Journal Article
Publication:	VIRULENCE
Publisher:	LANDES BIOSCIENCE
Additional Information:	Copy right for this article belongs to Landes Bioscience
Keywords:	acid tolerance response;acid shock proteins;epithelial cells; acidification;Salmonella containing vacuole;competitive indices
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	16 Jul 2012 11:14
Last Modified:	16 Jul 2012 11:14
URI:	http://eprints.iisc.ac.in/id/eprint/44843

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