Atomic force microscopy studies of bacterial interactions involved in Dental Caries

Dental caries is caused by processes occurring within the biofilm (plaque) that builds up on teeth and which is not always removed during routine brushing. While there are a wide variety of bacterial species within plaque, tooth decay is thought to be caused principally by species which produce high levels of lactic acid during processing of dietary sugars, such as Streptococcus mutans and lactobacilli. Not only does the ability to ferment sugars to produce acid result in acidic environments that promote enamel dissolution, but they promote extracellular polysaccharide production and increased bacterial adhesion to surfaces and to each other.

Atomic force microscopy (AFM) has the ability to image bacterial cell surfaces at high resolution and measure forces between surfaces. This project will involve a combination of in situ AFM imaging and force measurements on these species in controlled environments including those with sugar present and at varied pH to gain greater insight into the bacterial interactions triggering caries. Data will be acquired on cellular mechanics, cell surface morphology and adhesion forces with enamel surfaces to see how the bacteria respond to their environment.

There is a lack of detailed information on how bacterial species interact with each other and with the enamel surface. This project will obtain information on simple model bacterial biofilms in controlled conditions which will aid understanding of how cell surface polysaccharide mediates interactions critical to the development of caries. This should lead to new ideas and strategies for dealing with and preventing dental caries.

Candidate whose first language is not English must provide evidence that their English language is sufficient to meet the specific demands of their study, the Faculty minimum requirements are:

• British Council IELTS - score of 6.5 overall, with no element less than 6.0
• TOEFL iBT - overall score of 92 with the listening and reading element no less than 21, writing element no less than 22 and the speaking element no less than 23