- Title Information
- Title
- Quorum-Sensing Control of the Chromobacterium vaccinii Volatilome: A Molecular Genetic Study Enabled by Custom Image Analysis
- Type of Resource (primo)
- dissertations
- Name:
Personal
- Name Part
- Quarterone do Prado, Victor
- Role
- Role Term:
Text
- creator
- Name:
Personal
- Name Part
- Nau, Gerard
- Role
- Role Term:
Text
- Advisor
- Name:
Personal
- Name Part
- Cuomo, Christina
- Role
- Role Term:
Text
- Reader
- Name:
Personal
- Name Part
- Crego, Adam
- Role
- Role Term:
Text
- Reader
- Name:
Corporate
- Name Part
- Brown University. Biology and Medicine: Biotechnology
- Role
- Role Term:
Text
- sponsor
- Origin Information
- Copyright Date
- 2026
- Physical Description
- Extent
- viii, 79 p.
- digitalOrigin
- born digital
- Note:
thesis
- Thesis (Sc. M.)--Brown University, 2026
- Genre (aat)
- theses
- Abstract
- The quantification of microbial colony growth on solid media is currently compromised by a mismatch between the assumptions embedded in common biological image analysis tools and the imaging properties of petri dish images. These platforms were optimized for mammalian cell microscopy workflows and fail in three specific ways when applied to plate-based assays: intensity-based object identification logic misclassifies artifacts as biological objects, shape-based declumping algorithms fragment identified colonies, and the absence of any filtering allows noise to propagate and skew measurement outputs. This thesis addresses this translational gap and applies the resulting analysis framework to a molecular investigation of the regulatory mechanisms governing the volatile-mediated antifungal activity in Chromobacterium vaccinii. Four converging angles of genetic and pharmacological evidence establish that volatile inhibition of C. albicans by C. vaccinii is independent from the biosynthesis of the known antibiotic purple pigment produced by the bacteria, violacein, and strictly requires a functional CviR quorum sensing receptor to exhibit significant activity. Pigment-null strains of C. subtsugae and C. vaccinii were shown to retain equal inhibitory capacity, while a quorum sensing mutant of C. vaccinii failed to inhibit growth of Candida albicans to an extent indistinguishable from an uninhibited control. These findings set quorum sensing as the primary regulatory mechanism for the volatile antifungal output of C. vaccinii and narrow the candidate active compounds to the non-violacein fraction of CviR-regulated secondary metabolites, with relevance to antifungal drug discovery targeting priority fungal pathogens.
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/00967482")
- Topic
- Image analysis
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01019576")
- Topic
- Microbiology
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/00810432")
- Topic
- Antibiotics--Research
- Language
- Language Term (ISO639-2B)
- English
- Record Information
- Record Content Source (marcorg)
- RPB
- Record Creation Date
(encoding="iso8601")
- 20260516