During our clinical rotations in pediatrics, we encountered a deeply concerning trend: young children, aged between 5 and 10, suffering from relatively mild infections yet showing resistance to a broad spectrum of antibiotics in their antibiograms. In many cases, meropenem emerged as the sole effective treatment option. This alarming observation raises a critical question: If these children are resorting to antibiotics of last resort at such a young age, what therapeutic options will remain available to them in 20 to 30 years when resistance to even these drugs may develop? This pressing issue serves as the driving force behind our decision to focus our project on mitigating the environmental impact of meropenem, with the ultimate goal of curbing the spread of antibiotic resistance.
Our project, CADABRA (Cleaning Agent Developed for Antibiotic Resistance Annihilation), is primarily geared towards tackling the problem of antibiotic removal from wastewater. The growing threat of antimicrobial resistance poses a significant danger to both human and animal health. Antibiotics are frequently used in both human and veterinary medicine to combat infectious diseases. When an organism is treated with an antibiotic, a substantial portion of the medication is excreted through urine and finds its way into the sewer system or water supplies.
Antimicrobial resistance (AMR) hotspots have been identified in water environments, posing a major threat to human health. An illustrative case of AMR water pollution is observed in Bulgaria's Yantra River, flowing through agricultural regions and small communities lacking sewage networks (e.g., Shemshevo and Samovodene villages), as well as communities with sewage but inadequate wastewater regulations for antibiotics (e.g., Debelets town with 3900 residents) and the medium-sized town of Veliko Tarnovo (approximately 74,000 inhabitants).
The Environmental Quality Standards Directive (EQSD) is the legal framework for regulating the presence of specific substances or groups of substances designated as priority pollutants in surface waters due to the significant risks they pose to the aquatic environment. Antibiotics are among the main priority substances in the water sector. Directive 2013/39/EU updated the SCS for seven of the original 33 priority substances. Antibiotic levels in the Yantra River far exceed the limits set by the Environmental Quality Standards Directive (EQSD).
Our research's primary goal is to enhance the activity of naturally occurring metallo-β-lactamases, specifically VIM and NDM, to effectively catalyze the hydrolysis of various types of β-lactam compounds, including carbapenems like meropenem.
In pursuit of this objective, one of our key goals for this year is to utilize directed evolution and targeted mutagenesis techniques grounded in "in silico" models. These strategies aim to refine and enhance the properties of metallo-β-lactamases to optimize their performance in hydrolyzing β-lactam antibiotics.
Additionally, we are devoted to developing a systematic approach to monitor antibiotic concentrations in different liquid samples. Our proposed method involves the utilization of UV spectroscopy, enabling accurate and precise measurements of antibiotic levels.
The biosafety of the CADABRA cocktail is of utmost importance to us. We are eager to enhance both the biosafety and economic sustainability of our product. Our future plans involve adopting an alternative expression host known as Pichia pastoris. By employing this new organism, we aim to improve the safety profile of our production methods while simultaneously promoting the cost-effectiveness of our product.
In summary, CADABRA is dedicated to addressing the challenge of removing antibiotics from hospital wastewater. Through augmenting metallo-β-lactamases, implementing advanced techniques, and utilizing alternative expression hosts, we strive to achieve efficient antibiotic hydrolysis, reliable antibiotic monitoring methods, and enhanced biosafety and sustainability in our research and development efforts.