PROJECT DESCRIPTION
WATER TESTING
Water is fundamental to life, yet its purity is often taken for granted, especially in developed nations where safe drinking water is easily accessible. However, in the developing world, the reality can be starkly different. According to the World Health Organization, around 785 million people lack even a basic drinking-water service, including 144 million who are dependent on surface water. This makes water testing and sanitation indispensable, particularly in regions where waterborne diseases like cholera, dysentery, and typhoid are prevalent.
Before safe water can reach communities, it has to undergo rigorous testing. Just as gold goes through an exploratory phase, so too does water undergo qualitative and quantitative analysis to detect potential contaminants. The presence of pathogenic microbes, heavy metals, or excess chemicals in water can lead to severe health implications, making water testing an essential preliminary step. Such testing ensures that the water being consumed meets international safety standards, thereby preventing potential outbreaks.
However, the challenges related to water sanitation in the developing world are vast. For many impoverished communities, the infrastructure for clean water delivery and sewage treatment is either non-existent or severely compromised. Consequently, even when water sources are tested and treated, the delivery system can re-contaminate it. Additionally, the high cost of sophisticated water testing equipment and methods can be prohibitive for many regions.
Thus, water testing and sanitation are paramount, especially in the developing world. The benefits extend beyond health – improving access to clean water can boost economic productivity, empower women (who are often tasked with fetching water), and promote overall societal wellbeing. Just as artisanal mining supports numerous livelihoods, access to clean water determines the quality of life for countless individuals globally.
EXISTING SOLUTIONS
Culture-based Methods
Culture-based tests involve the growth of microorganisms in specific media under controlled conditions to detect and identify pathogens present in a sample, such as blood, urine, or tissue. By spreading the sample onto or into nutrient-rich substances called culture media and incubating under conditions conducive to microbial growth, pathogens, if present, will multiply and can be subsequently identified. While these tests are foundational in microbiology and critical for diagnosing various infections, they have limitations. For instance, they can be time-consuming, taking days to weeks to yield results. Additionally, not all microorganisms can be easily cultured in a laboratory setting, and some fastidious organisms might require very specific growth conditions or might not grow at all. There's also the risk of contamination, which can lead to false-positive results.
Traditional ELISA Methods
The traditional ELISA method is a well-established technique for detecting and quantifying substances such as peptides, proteins, and hormones. However, it has limitations in its usability, especially at the bedside, due to its requirement for multiple liquid-handling steps. Furthermore, ELISA necessitates two distinct binding modules for the target: one for capturing the target and another for reading the result. This complexity extends the process, involving time-consuming incubation and washing steps which impede its efficiency.
Lateral Flow Assays
Lateral flow assays stand out for their speed and cost-effectiveness, making them a popular choice for rapid testing. However, they come with their own set of challenges. These assays often suffer from limited sensitivity, reduced reproducibility, and poor quantitative performance. Similar to the ELISA, they also demand two binding modules for the target, one for capture and another for readout. These drawbacks can affect the accuracy and reliability of the test results.
Naturally, in scarce resource settings two of these methods, culture-based and traditional ELISA, are not applicable since they require a laboratory setting and trained technicians. Lateral flow immunochromatographic assays are fast and cheap, but they have limited sensitivity, reproducibility, and poor quantitative performance. For reliable water testing, we need a sensor that gives fast results, is sensitive, and gives quantitative results.
RELEVANT SUSTAINABLE DEVELOPMENT GOALS
Clean Water and Sanitation
Rapid testing for water quality is essential to determine clean water sources and inform sanitation measures.
Good Health & Well-Being
Water-associated infections compromise the health of hundreds of millions of people. Access to clean water is crucial to ensure global health.
Sustainable Cities & Communities
Clean water and sanitation are vital for the sustainable development of cities and communities as they ensure a healthy urban population, support sustainable infrastructure, and reduce environmental degradation in densely populated areas.
OUR CONTRIBUTION TO PROVIDE ACCESSIBLE WATER TESTING TECHNOLOGY
Bac2Glow targets Sustainable Development Goal 6 - to ensure availability and sustainable management of water and sanitation for all.
Our solution removes the need for a lab, trained staff to carry out the tests, the long wait times for results, and the lack of coverage of non-coliform bacteria.
Bac2Glow gives results within two minutes so that immediate action can be taken.
A positive result is shown by a luminescent signal which can be detected by a phone camera. This has two implications: firstly, the kits are easy to use and read so that community level testing can become a routine. Secondly, test result data can be instantly uploaded to databases for better data coverage that includes exact time and location.
Our tests are strain-specific so can identify any type of bacterial contamination.
Our kits are small, easy to transport to remote locations, and durable to travel.
Our Technology
Bac2Glow is developing rapid, cheap, and specific bacterial testing for the detection of water-contaminating pathogens.
Using research published by the Baker Lab, as well as AI vision software running on a mobile phone, we will be able to detect pathogens at a rate that is quicker, cheaper, and simpler than alternatives. This will be targeted at low-resource settings in a bid to reduce water contamination related deaths and illness.
Nano-luciferase, which we are using as a reporter, has been shown to be detectable by the naked eye. We are aiming to make the signal visible for simple yes/no detection and quantifiable by a simple gadget or a phone camera for more advanced data collection.
Our binders are based on bacteriocins – naturally-occurring and species-specific antibacterial proteins that are secreted by bacteria in stressful conditions. Bacteriocins have evolved to be specific to bacterial species, and so we can use this specific binding to create bacterial testing technology.
Our biosensor will be stable and portable, allowing detection both on-site and at-home. As the result is luminescence, it is easily interpretable. Moreover, it does not require a complicated assembly or testing protocol. Our design is based on inserting a binding domain into a modular biosensor. The biosensor, when bound to the target, will reconstitute luciferase and release a signal. Being modular will mean it will be easily adaptable to new pathogens. This can be crucial in case of an epidemic or other state of biocontamination, as it will allow us to develop new sensors quickly in response to threats.
Bacteriocins
Bacteriocins are proteinaceous or peptide toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strains. They are typically considered narrow-spectrum antibiotics, unlike broad-spectrum antibiotics that target a wide range of bacterial species.
Many bacteriocins have a modular organization into different protein domains that specialize in a given function:
- Binding domain: This domain is responsible for the initial interaction with the target bacteria. It recognizes and attaches to specific receptors on the surface of susceptible bacterial cells, ensuring the bacteriocin's specificity. The receptor is often a protein or other component of the outer membrane in Gram-negative bacteria.
- Effector domain: Once inside the target bacteria or in its membrane, this domain is responsible for the bacteriocin's lethal action. Depending on the specific bacteriocin, it might kill the target bacteria by degrading its DNA, RNA, or proteins, by inhibiting cell wall synthesis, or by forming pores in the cell membrane, among other mechanisms.
- Translocation domain: After the bacteriocin binds to the target cell, this domain facilitates the import of the bacteriocin into the cell or across the cell membrane. It helps the bacteriocin to cross the outer membrane (in Gram-negative bacteria) and reach the cytoplasmic membrane, often through interacting with specific proteins that are part of the import machinery of the target bacteria.
Part 1 of Our Solution: Testing at Water Sources
- WHO, NGOs, or governments test water sources locally and nationally regularly. This is for regulatory oversight and surveillance. Currently, results from water source testing take days to process - leaving people without water, drinking dirty water, or traveling miles to find alternative sources.
- Singular sources can supply villages or towns which house thousands of people. The testing at these sites needs to be accurate, quantitative, and strain-specific.
- Currently, only culturing methods are used, which are subpar and give little information about the situation. This needs to be done regularly and needs to provide as much information as possible.
- By providing rapid, quantifiable results we can reduce wait times, increase the understanding of the contamination, and reduce the spread. Because they are easy to use and interpret, anyone can do these tests.
- Test water at the source
Part 2 of Our Solution: At-Home Testing
- Household testing is used to understand the bigger picture. Is the water people are drinking safe or has it been contaminated after the source? This is mainly done by NGOs and only happens in emergencies.
- In this use case, the ease of use, speed, and cost per test of the testing kit are really important. Currently, they also use the culturing method - slow and not able to detect non-coliform bacteria, which are very dangerous like Pseudomonas.
- At-home, community-led testing that is easy to do is essential for tackling water contamination issues. This will allow organizations to gather huge amounts of data on water quality in different villages, towns, and areas.
- In these cases, the same technology can provide clear positive-negative results for different strains as well as safe-not safe results. This will be hugely important in understanding the water safety across vast areas, especially in emergency responses.
- Test water at the endpoint.