Detection of Escherichia coli Using Loop-Mediated Isothermal Amplification for a Novel Air Sampling System

Introduction: This paper presents an innovative air sampling and rapid detection system for airborne bacteria in the environment. Objective: The proposed system aims to enhance the efficiency and accuracy of airborne bacterial detection by integrating an improved air sampler with a rapid nucleic acid amplification method. Methods: The system incorporates an air sampler with a cutting-edge nucleic acid amplification method known as loop-mediated isothermal amplification to detect bacterial pathogens precisely and efficiently. The air sampling system comprises a specialized collection device capable of capturing airborne bacteria particles, and an automatic sample extraction system from this device. Subsequently, nucleic acid amplification is performed using the LAMP technique, which can amplify at a constant temperature (65 °C) without the need for thermal cycling as with polymerase chain reaction, providing a faster, less costly, isothermal, and highly sensitive method for detecting target bacterial DNA. In addition, a simple, easily portable, low-cost, high-efficiency heating device that can be operated at constant temperature for the desired time has been developed for the LAMP reactions. Results: The results demonstrate the capability of the system to detect a broad-spectrum bacteria concentration with high sensitivity and specificity, making it a valuable tool for real-time monitoring and surveillance. The limit of detection of the air sampling system is 65 CFU L^-1, determined through a series of experiments. Conclusions: The proposed air sampling system, coupled with the LAMP technology, offers a promising solution for addressing the limitations associated with traditional bacterial detection methods in airborne environments, such as insufficient sensitivity, extended processing times, microbial drying, isolating target microorganisms from others, and challenges in detecting low concentrations, paving the way for enhanced public health and safety measures.