Expression of phospholipase D, the major virulence factor of Corynebacterium pseudotuberculosis, is regulated by multiple environmental factors and plays a role in macrophage death
- 1 July 2007
- journal article
- Published by Microbiology Society in Microbiology
- Vol. 153 (7), 2203-2211
- https://doi.org/10.1099/mic.0.2007/005926-0
Abstract
Corynebacterium pseudotuberculosis is the aetiological agent of caseous lymphadenitis, a disease affecting sheep and goats. Phospholipase D (Pld), a major virulence determinant of C. pseudotuberculosis, is believed to play a critical role in dissemination of bacteria from the site of infection to the lymph nodes. Although the pld gene has been studied for some time, it is only recently that it has been identified as being down-regulated following heat shock from 37 to 43 °C. To gain insights into the mechanisms of Pld action, this study investigated how it was regulated under varying environmental conditions. Studies measuring pld mRNA levels or utilizing a reporter construct containing the pld promoter upstream of a gfp gene were performed. These showed that pld was upregulated in a cell-density-dependent manner, was regulated by heat shock at all cell-culture densities, and was highly expressed in a tissue-culture macrophage-infection model. Finally, the expression of Pld by intracellular C. pseudotuberculosis was shown to play a small but significant role in the reduction of macrophage viability following infection. This study demonstrates that the regulation of C. pseudotuberculosis pld is complex. This regulatory complexity may play an important role in allowing the pathogen to successfully adapt to the changing host environment during infection, migration, establishment and disease progression.Keywords
This publication has 31 references indexed in Scilit:
- Identification of macrophage induced genes of Corynebacterium pseudotuberculosis by differential fluorescence inductionMicrobes and Infection, 2005
- Identification and role in virulence of putative iron acquisition genes fromCorynebacterium pseudotuberculosisFEMS Microbiology Letters, 2002
- Caseous lymphadenitis vaccine development: site-specific inactivation of the Corynebacterium pseudotuberculosis phospholipase D geneVaccine, 1995
- Targeted mutagenesis of the phospholipase D gene results in decreased virulence ofCorynebacterium pseudotuberculosisMolecular Microbiology, 1994
- Construction of an overproduction vector containing the novel srp (sterically repressed) promoterProtein Science, 1994
- Immunisation against ovine caseous lymphadenitis: comparison of Corynebacterium pseudotuberculosis vaccines with and without bacterial cellsAustralian Veterinary Journal, 1991
- Experimental Corynebacterium pseudotuberculosis infection in lambs: kinetics of bacterial dissemination and inflammationVeterinary Microbiology, 1991
- Static and dynamic lipid asymmetry in cell membranesBiochemistry, 1991
- The effects of caseous lymphadenitis on wool production and bodyweight in young sheepAustralian Veterinary Journal, 1988
- Pathogenesis of caseous lymphadenitis in sheep and goatsAustralian Veterinary Journal, 1986