Caffrey, V. | bioRxiv Science

bioRxiv2024

Towards Real-Time Airborne Pathogen Sensing: Electrostatic Capture and On-Chip LAMP Based Detection of Airborne Viral Pathogens

Considerable loss of life, economic slowdown, and public health risk associated with the transmission of airborne respiratory pathogens was underscored by the recent COVID-19 pandemic. Airborne transmission of zoonotic diseases such as the highly pathogenic avian influenza (HPAI) and porcine reproductive and respiratory syndrome virus (PRRSV) has caused major disruptions to domestic and global food security. Current ambient air pathogen monitoring systems involves the collection of air samples from indoor settings suspected of viral contamination, followed by subsequent processing of capture samples to determine the presence and species of airborne viral matter. Nucleic acid amplification techniques are considered the gold standard for pathogen diagnostics. Currently, the necessary extraction and purification of viral RNA from air collector systems prior to sample analysis is both time consuming and performed manually. A monitoring system with separate air sampling and biochemical detection procedures is prone to delay the response to emergent viral threats. In this paper, we present a pathogen monitoring system that overcomes these limitations related to extraction and purification of viral samples and lays the groundwork for a real-time monitor for airborne viral pathogens. We demonstrate a high flow electrostatic precipitator system, that uses small collection wells as counter electrodes for pathogen collection. Integrated reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP) is used for detection of captured viral matter within wells. On-chip heating of collection wells is enabled by integrated planar heaters and small volumes of reagent (30 L) directly to the collection wells. We present the design of such a system and show experimental results that demonstrate the use of this device for detection of aerosolized SARS-CoV-2 virus like particles (VLPs), a model pathogen for SARV-CoV-2.

bioengineering↗

bioRxiv2024

VLP-Based Model for Study of Airborne Viral Pathogens

The recent COVID-19 pandemic has underscored the danger of airborne viral pathogens. The lack of model systems to study airborne pathogens limits the understanding of airborne pathogen distribution, as well as potential surveillance and mitigation strategies. In this work, we develop a novel model system to study airborne pathogens using virus like particles (VLP). Specifically, we demonstrate the ability to aerosolize VLP and detect and quantify aerosolized VLP RNA by Reverse Transcription-Loop-Mediated Isothermal Amplification (RT-LAMP) in real-time fluorescent and colorimetric assays. Importantly, the VLP model presents many advantages for the study of airborne viral pathogens: (i) similarity in size and surface components; (ii) ease of generation and noninfectious nature enabling study of BSL3 and BSL4 viruses; (iii) facile characterization of aerosolization parameters; (iv) ability to adapt the system to other viral envelope proteins including those of newly discovered pathogens and mutant variants; (v) the ability to introduce viral sequences to develop nucleic acid amplification assays. ImportanceStudy and detection of airborne pathogens is hampered by the lack of appropriate model systems. In this work we demonstrate that noninfectious Virus Like Particles (VLP) represent attractive models to study airborne viral pathogens. Specifically, VLP are readily prepared, are similar in size and composition to infectious viruses, and are amenable to highly sensitive nucleic acid amplification techniques.

molecular biology↗