We aimed to produce a test which detects the abundance of targeted bacteria present on skin using DNA aptamers. This rapid test has the potential to diagnose dysbiosis in skin microbiota which leads to acne and atopic dermatitis. The test can be suitable for home use, use in research labs and use in hospitals.
Our test was aimed for acne vulgaris, the official name for the common form of the disease acne. In this wiki, this will be continuously referred to as acne.
To get a better understanding of what constitutes a healthy microbiome we planned to collect samples from people with and without skin problems and sequence their skin microbiome. The rapid test is based on affinity binding and detection using colorimetry. The detection of the selected bacteria is done with polydiacetylene (PDA) which changes colour from blue to red when said selected bacteria is present in the sample. The intensity of the red colour correlates to the abundance of the species on the skin, although this is only an indication of relative concentration, rather than a hard value. Unfortunately, PDA requires UV light for polymerization, which does affect the usability of the test. We are hoping to make a polymerized version of PDA stable enough to include directly in the test.
When it comes to detecting the bacteria, and which bacteria is relevant for our purposes, specific species which are present on the skin will be targeted, for which specific aptamers have been selected. A higher abundance of Staphylococcus aureus on the skin has been shown to correlate with the severity of atopic dermatitis. As an aside, atopic dematitis is a skin disease characterized by flareups of redness and itchiness. It is more commonly known by the name "ezcema".
Alternatively, Cutibacterium acnes (C.acnes) Phylotype IA1 is found to be abundant in acne skin by multiple metagenomic studies. As a result, these were the selected bacteria that we decided on for our rapid test!
A general aptamer for all gram positive bacteria (teichoic acid) was selected for use as a control. Aptamers developed include:
Aptamers targeting Protein A, a surface protein of S.aureus, are already developed, and so required no further work from our team. The colorimetric detection involves the development of a model which gives the test output based on the results. This is the major model worked on by our drylab subgroup, as well as perform simulations regarding the aptamer. If you'd like to read about this model in more detail please see here. The present method for delivering results is a pH-like solution where the user gets a reference band of different intensities of red that corresponds to the abundance of the bacterium. A certain abundance is marked as the threshold for dysbiosis.
We plan to incorporate our aptamers into a biobrick, and in addition, we will optimise a biobrick for protein A. This allowed us to train with cloning right from the start of our project.
Project Promotion Video
If the above video doesn't work for you, feel free to watch our promotion video on Mikroskin here!
All the content on this website is based on the example wiki and has been used for demonstration only.
Our dry-lab has done a fantastic job working on the model showing our project for you to visualise here!Read More