Temperature regulation of virulence factors in the pathogen Vibrio coralliilyticus

• Published in: The ISME Journal 2012-04, Vol.6 (4), p.835-846
• Main Authors: Kimes, Nikole E, Grim, Christopher J, Johnson, Wesley R, Hasan, Nur A, Tall, Ben D, Kothary, Mahendra H, Kiss, Hajnalka, Munk, A Christine, Tapia, Roxanne, Green, Lance, Detter, Chris, Bruce, David C, Brettin, Thomas S, Colwell, Rita R, Morris, Pamela J
• Format: Article
• Language: English
• Subjects: Animals; Anthozoa - microbiology; Antibiotic resistance; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bioassays; Bioluminescence; Biomedical and Life Sciences; Bleaching; Climate Change; Climate change models; Coral Reefs; Cytotoxicity; Ecology; Evolutionary Biology; Genome, Bacterial; Global climate; Infectious diseases; Life Sciences; Marine organisms; Microbial Ecology; Microbial Genetics and Genomics; Microbiology; Oceans and Seas; Original; original-article; Outbreaks; Pathogens; Proteomics; Sea surface temperature; Seawater - microbiology; Spring; Summer; Temperature; Vibrio; Vibrio - genetics; Vibrio - metabolism; Vibrio - pathogenicity; Virulence; Virulence Factors - genetics; Virulence Factors - metabolism
• ISSN: 1751-7362; 1751-7370
• DOI: 10.1038/ismej.2011.154

Sea surface temperatures (SST) are rising because of global climate change. As a result, pathogenic Vibrio species that infect humans and marine organisms during warmer summer months are of growing concern. Coral reefs, in particular, are already experiencing unprecedented degradation worldwide due in part to infectious disease outbreaks and bleaching episodes that are exacerbated by increasing SST. For example, Vibrio coralliilyticus , a globally distributed bacterium associated with multiple coral diseases, infects corals at temperatures above 27 °C. The mechanisms underlying this temperature-dependent pathogenicity, however, are unknown. In this study, we identify potential virulence mechanisms using whole genome sequencing of V. coralliilyticus ATCC (American Type Culture Collection) BAA-450. Furthermore, we demonstrate direct temperature regulation of numerous virulence factors using proteomic analysis and bioassays. Virulence factors involved in motility, host degradation, secretion, antimicrobial resistance and transcriptional regulation are upregulated at the higher virulent temperature of 27 °C, concurrent with phenotypic changes in motility, antibiotic resistance, hemolysis, cytotoxicity and bioluminescence. These results provide evidence that temperature regulates multiple virulence mechanisms in V. coralliilyticus, independent of abundance. The ecological and biological significance of this temperature-dependent virulence response is reinforced by climate change models that predict tropical SST to consistently exceed 27 °C during the spring, summer and fall seasons. We propose V. coralliilyticus as a model Gram-negative bacterium to study temperature-dependent pathogenicity in Vibrio -related diseases.