Development of a biosensor to detect Candida albicans colonisation of denture materials

This project will investigate the unique signature created by microbial volatile organic compounds released from the yeast Candida albicans. Following this, a biosensor capable of detecting this unique signature will be developed, relating to C. albicans growth on/colonisation of denture materials, and clinical potential will be explored.

Background:
Candida albicans is a dimorphic fungus capable of causing denture stomatitis, the most common form of oral candidiasis present in up to 60% of denture wearers. Candida remain the most important cause of opportunistic infections worldwide, affecting predominantly patients over 65 years old. The rapidly growing elderly population has specific physiological characteristics, which makes it susceptible to subsequent infection due to Candida species (Flevari et al., 2013). Symptoms include mucosal bleeding, swelling, burning and other painful sensations, halitosis, unpleasant taste and dryness in the mouth (Dorocka-Bobkowska et al., 2010). Oral candidiasis is most commonly occurs with denture wearers compared to non-denture wearers (Daniluk et al., 2006), and is capable of causing systemic infection (Hebecker et al., 2014).

The diagnosis of oral candidiasis can be visual or swabbed and cultured (taking upwards of 24 hours), followed by anti-fungal medication and disinfection of colonised dentures. Chairside diagnosis using a sensor would provide a rapid, confirmatory diagnosis, enabling more confident prescription of appropriate treatment.

Like most other fungi, C. albicans is capable of producing microbial volatile organic compounds (MVOCs), with over 150 described in the literature. Previous research at Manchester Metropolitan University in the elite research group Microbiology at Interfaces (led by Professor Joanna Verran) has shown MVOCs produced by fungi, including C. albicans growing on denture material, are identifiable with solid phase micro-extraction (SPME) and gas chromatography-mass spectrometry (GC-MS). Additional work by Verran in collaboration with the elite research group Advanced Materials and Surface Engineering (led by Professor Craig Banks) resulted in the development of one-shot disposable sensors capable of detecting MVOCs from fungi growing on film reel (Bingley et al., 2012).

This research project would investigate a unique signature profile of MVOCs released from C. albicans and develop a sensor for rapid, chairside diagnosis for C. albicans colonisation.

Objectives

The objectives are:
•Profile MVOCs emitted from planktonic cultures of C. albicans
•Investigate factors affecting the MVOC profile of C. albicans colonised on denture material and in biofilm including: ◦different substrata such as acrylic, silicone and tissue conditioner
◦different metabolic substrates
◦mixed cultures of microorganisms

•Identify unique MCOV patterns for C. albicans
•Develop a prototype biosensor using thin film printing technology capable of detecting the unique MVOC pattern
•Test the biosensor for accuracy and reliability in vitro

The supervisory team for this project will be Prof. Joanna Veran, Prof. Craig Banks, James Redfern, and Dr Lisa Coulthwaite

The closing date for applications is 31st January 2017.
To apply, please use the form on our web page: http://www2.mmu.ac.uk/study/postgraduate/apply/postgraduate-research-course/ - please note, CVs alone will not be accepted.

For informal enquiries, please contact: [Email Address Removed]
Please quote the Project Reference in all correspondence.