A high-flow portable biological aerosol trap (HighBioTrap) for rapid microbial detection

Abstract

A B S T R A C TBioaerosols exposure can lead to many adverse health effects and even result in death if highly infectious agents involved. Apparently, there is a great need for rapid detection of bioaerosols, for which air sampling often is the first critical step. However, currently available samplers often either require an external power and/or with low sampling flow rate, thus falling short of providing a practical solution when response time is of great concern.Here, we have designed and evaluated a new portable high volume bioaerosol sampler named as HighBioTrap through optimizing its operating parameters. The sampler was operated at a sampling flow rate of 1200 L/min, with an impaction velocity of about 10.2 m/s (S/W = 1.5, T/ W = 1), while the weight of the sampler is about 1.9 kg. The performances of the HighBioTrap sampler were tested both in lab controlled and natural environments (outdoor and indoor environments in a university building) along with the reference sampler-the BioStage impactor using aerosolized Polystyrene (PS) uniform microspheres of various sizes, aerosolized bacteria and also ambient air particles. The microbial community structures of collected culturable bacterial aerosol particles both by the HighBioTrap and the BioStage impactor in the natural environments were analyzed using gene sequence method.Experimental results with PS particles showed the HighBioTrap has a cutoff size of~2 µm. The widely used impactor design equation was found to be not applicable for predicting the performance of the HighBioTrap due to its large Reynolds number. When sampling aerosolized individual Pseudomonas fluorescens and Bacillus subtilis bacterial particles, the HighBioTrap had physical collection efficiencies of 10% and 20%, respectively. Despite the higher desiccation effects introduced by higher flow rate, the HighBioTrap was shown to obtain a higher microbial diversity than the BioStage impactor for both in outdoor and indoor environments given the same sampling time (p < 0.01). Our data also showed that most of the desiccation effects might have occurred between 3 and 5 min of the sampling and an impaction velocity of around 10 m/s might be a close-to-optimal impaction velocity for collecting most environmental bacterial aerosols while maximally preserving their culturability. This work contributes to our understanding of microbial sampling stress (impaction velocity and sampling time), while developing a portable high volume sampler. The HighBioTrap sampler could find its great efficiencies in qualitative microbial aerosol detection and analysis, such as investigation of microbial aerosol diversity for a particular environment, or when the low level of pathogens is present and detection time is of great concern.

Time- and size-resolved bacterial aerosol dynamics in highly polluted air: new clues for haze formation mechanism

“…Between February 2018 and May 2018, air samples were collected for a 24-hr time period for each day in three different pollution episodes (14 −208 ng/m 3 ) using the HighBioTrap sampler (Beijing dBlue Tech, Inc, Beijing, China) at an air flow rate of 1000 L/min for 20 min for each sample on Peking University campus (40°00′N, 116°32′E). The detailed sampling protocol was described for the HighBioTrap in our previous work(Chen and Yao, 2018). For each PM 2.5 pollution episode, particulate matter samples were collected in duplicates using the HighBioTrap at an interval of every 2 or 4 hours on an aluminum membrane coated with 600 μL mineral oil at a height of 1.5 m above the ground.…”

Combining culturing and 16S rDNA sequencing to reveal seasonal and room variations of household airborne bacteria and correlative environmental factors in nanjing, southeast china

“…The collection performance has been clearly demonstrated as a capable method of bioaerosols identification in a previous study. 55 Concurrently, the indoor temperature, RH (relative humidity), and PM 2.5 of each home were measured. Green Eye (AZ 7798, Hengxin Instrument Corp., Shanghai, China) was employed to record the temperature ( o C) and RH (%) during the sampling period.…”

A Robot Assisted High-flow Portable Cyclone Sampler for Bacterial and SARS-CoV-2 Aerosols

“…Previously, as the world leading authority, the World Health Organization, has not recognized the importance of aerosol exposure of SARS-CoV-2 despite of vast amount of evidences emerging (WHO, 2020a;2020b;Prather et al, 2020). The dispute or discrepancy is partially due to the use of different terminologies on one hand by different disciplines (WHO, 2020a;2020b;Prather et al, 2020;Wilson et al, 2020); and the other hand the available qualified techniques or methods for biological aerosol studies are fewer or not readily available, and many of them are very outdated (Chen and Yao, 2018;Zheng et al, 2018). All these problems contribute to the difficulty of studying the critical scientific questions in bioaerosol field (Mainelis, 2020), including airborne transmission of COVID-19.…”