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RESEARCH PRODUCT
The Fish Pathogen Vibrio vulnificus Biotype 2: Epidemiology, Phylogeny, and Virulence Factors Involved in Warm-Water Vibriosis
Carmen AmaroDavid PajueloChung-te LeeEva SanjuánLien-i HorRodolfo BarreraBelén Fouzsubject
Microbiology (medical)Gene Transfer HorizontalVirulence FactorsPhysiologyFish farmingBacterial ToxinsVirulenceVibrio vulnificusMicrobiologyFish DiseasesMicePlasmidReceptors TransferrinGeneticsAnimalsHumansVibrio vulnificusGenePathogenPhylogenyEelsGeneral Immunology and MicrobiologyEcologybiologyCell Biologybiology.organism_classificationImmunity InnateInfectious DiseasesVibrio InfectionsHorizontal gene transferWater MicrobiologyBacterial outer membranePlasmidsdescription
ABSTRACT Vibrio vulnificus biotype 2 is the etiological agent of warm-water vibriosis, a disease that affects eels and other teleosts, especially in fish farms. Biotype 2 is polyphyletic and probably emerged from aquatic bacteria by acquisition of a transferable virulence plasmid that encodes resistance to innate immunity of eels and other teleosts. Interestingly, biotype 2 comprises a zoonotic clonal complex designated as serovar E that has extended worldwide. One of the most interesting virulence factors produced by serovar E is RtxA1 3 , a multifunctional protein that acts as a lethal factor for fish, an invasion factor for mice, and a survival factor outside the host. Two practically identical copies of rtxA1 3 are present in all biotype 2 strains regardless of the serovar, one in the virulence plasmid and the other in chromosome II. The plasmid also contains other genes involved in survival and growth in eel blood: vep07 , a gene for an outer membrane (OM) lipoprotein involved in resistance to eel serum and vep20 , a gene for an OM receptor specific for eel-transferrin and, probably, other related fish transferrins. All the three genes are highly conserved within biotype 2, which suggests that they are under a strong selective pressure. Interestingly, the three genes are related with transferable plasmids, which emphasizes the role of horizontal gene transfer in the evolution of V. vulnificus in nutrient-enriched aquatic environments, such as fish farms.
year | journal | country | edition | language |
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2015-07-18 | Microbiology Spectrum |