10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
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Pathogenic Bioaerosol Detection in Under 30 Minutes
Robert Ferguson, Corinne Whitby, Dumbrell Alex, IAN COLBECK, University of Essex, Colchester, CO4 3SQ, UK
Abstract Number: 687 Working Group: Bioaerosols
Abstract Deleterious health effects can arise following exposure to infective airborne microorganisms (bioaerosols). However, the risk of human exposure to bioaerosols remains difficult to quantify in real time. Currently, regulators rely on culture-based methods targeting only a single pathogen (i.e. Aspergillus fumigatus) as the industry’s ‘gold’ standard. Such approaches are labour and time intensive, taking days to produce results. As the vast majority of microorganisms cannot be cultured these methods underestimate microbial loadings and key pathogens that may also be present are routinely overlooked. We present a tool for detection of specific bioaerosol pathogens in the field in less than 30 minutes.
Our method is based on isothermal amplification (LAMP) of DNA. LAMP is ideal for pathogen detection as it can identify one copy of a specific gene target in less than an hour [1]. The time from sample collection to result is under 30 minutes. We can achieve this as the result is shown by a colour change in the reaction mixture (no gel electrophoresis is required). Additionally the method is highly portable, no specialized equipment is required and a heat block can be used. LAMP is more sensitive than PCR; we have been able to identify < 5 E. coli cells without DNA extraction. The method is also highly specific due to the use of 2-3 primer pairs; we are able to target specific stains or pathogen virulence genes. The method can also be combined with fluorescent methods for real-time quantification in the field on battery powered platforms such as the OptiGene II and III. Currently, we are developing assays for the detection of key pathogens including Aspergillus fumigatus and niger, E. Coli, Legionella pneumophila, Bacillus anthracis, and Bordetella pertussis. The method can also easily be adapted to detect specific virulence genes (e.g. E. Coli STa) or antimicrobial resistance genes when taxonomic identification alone is not sufficient.
This method is one of a suite of tools we are developing based on high-throughput sequencing and chemical marker analysis which represent the next-generation of methods for in-situ biomonitoring of bioaerosols. We envisage that soon regulators will be able to detect and monitor key pathogens in real time.
[1] T. Notomi, H. Okayama, H. Masubuchi, T. Yonekawa, K. Watanabe, N. Amino, and T. Hase, “Loop-mediated isothermal amplification of DNA.,” Nucleic Acids Res., vol. 28, no. 12, p. E63, Jun. 2000.