Research Seminar: Rachel Canty

A research seminar from UNC Marine Sciences graduate student, Rachel Canty. Presented by the UNC-CH Department of Marine Sciences and UNC’s Institute of Marine Sciences (IMS). The main location of this event will be in room 222 at IMS in Morehead City, NC. The seminar will be streamed live to seminar room G201 on the ground floor of Murray Hall on UNC-CH campus in Chapel Hill, NC. This event will be held on Monday, February 5th at 12:20pm.

Seminar Title: Interspecies and intraspecies killing by Vibrio vulnificus correlates with the presence of type VI secretion system 2 

Abstract: Type VI secretion systems (T6SS) are found in approximately 25% of all sequenced Gram negative bacterial genomes. One species known to contain T6SS is Vibrio vulnificus, the leading cause of seafood-borne death in the US primarily through the ingestion of raw or undercooked oysters. Unlike T1SS and T2SS also found in V. vulnificus, T6SS secretes not only anti-eukaryotic toxins (which aid in gut pathogenesis), but anti-prokaryotic toxins as well, indicating that they are able to kill other bacteria including V. vulnificus strains that do not contain relevant immunity proteins.

V. vulnificus contains two types of T6SS. All strains contain T6SS type 2 (T6SS2), whereas very few strains contain T6SS type 1 (T6SS1). In 2016, killing of Vibrio fluvialis by V. vulnificus through T6SS1 was demonstrated. Here we have demonstrated interspecies (killing of T6SS negative V. fischeri) and instraspecies killing by Vibrio vulnificus strains that do not appear to contain a T6SS1, indicating killing by use of T6SS2. Research to confirm this is ongoing.

Killing through T6SS2 may provide greater insight into V. vulnificus ecology and aid in reducing human risk to V. vulnificus pathogenesis.