Vibrio vulnificus Type 6 Secretion System 1 Contains Anti-Bacterial Properties

• Published in: PloS one 2016-10, Vol.11 (10), p.e0165500-e0165500
• Main Authors: Church, Selina R, Lux, Thomas, Baker-Austin, Craig, Buddington, Sam P, Michell, Stephen Ll
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Analysis; Animals; Antibacterial agents; Antibiosis - genetics; Antibiotics; Bacteria; Biology and Life Sciences; Climate change; Contamination; Environmental science; Fish; Food contamination; Gastroenteritis; Gene Expression Regulation, Bacterial; Gene Order; Gene sequencing; Genes; Genetic Variation; Genome, Bacterial; Genomes; Genomics; Health aspects; Infection; Infections; Killing; Kinases; Larva - microbiology; Medicine and Health Sciences; Microbial Viability - genetics; Mortality; Mutation; Oysters; Pathogenesis; Pathogens; Physical Sciences; Population biology; Population dynamics; Proteins; Researchers; Salinity; Salt-Tolerance - genetics; Seafood; Seafoods; Secretion; Sepsis; Species; Strains (organisms); Temperature; Thermoregulation; Type VI Secretion Systems - genetics; Vibrio; Vibrio cholerae; Vibrio Infections - microbiology; Vibrio vulnificus; Vibrio vulnificus - physiology; Virulence; Virulence (Microbiology); Virulence factors; Virulence Factors - chemistry; Virulence Factors - genetics; Water-borne diseases; Waterborne diseases; Wound infection
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0165500

Vibrio vulnificus is a bacterium responsible for severe gastroenteritis, sepsis and wound infections. Gastroenteritis and sepsis are commonly associated with the consumption of raw oysters, whereas wound infection is often associated with the handling of contaminated fish. Although classical virulence factors of this emerging pathogen are well characterised, there remains a paucity of knowledge regarding the general biology of this species. To investigate the presence of previously unreported virulence factors, we applied whole genome sequencing to a panel of ten V. vulnificus strains with varying virulence potentials. This identified two novel type 6 secretion systems (T6SSs), systems that are known to have a role in bacterial virulence and population dynamics. By utilising a range of molecular techniques and assays we have demonstrated the functionality of one of these T6SSs. Furthermore, we have shown that this system is subject to thermoregulation and is negatively regulated by increasing salinity concentrations. This secretion system was also shown to be involved in the killing of V. vulnificus strains that did not possess this system and a model is proposed as to how this interaction may contribute to population dynamics within V. vulnificus strains. In addition to this intra-species killing, this system also contributes to the killing of inter bacterial species and may have a role in the general composition of Vibrio species in the environment.