Design and performance of a single-pass bubbling bioaerosol generator

Mainelis, Gediminas; Berry, David; An, Hey Reoun; Yao, Maosheng; DeVoe, Kevin; Fennell, Donna E.; Jaeger, Rudolph J.

doi:10.1016/j.atmosenv.2005.02.043

Cited by 50 publications

(49 citation statements)

References 13 publications

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“…It is important to note, however, that the method chosen for particle generation in the laboratory strongly impacts the size distribution of aerosolized particles. For example, higher concentrations of an aqueous suspension of particle material generally produce larger particles, and the mechanical force used to agitate powders or aerosolize bacteria can have strong influences on particle viability and physical agglomeration or fragmentation of the aerosol (Mainelis et al, 2005). So, while the absolute size of particles shown here is not a key message, the relative fluorescence at a given size can be informative.…”

Section: Fluorescence Intensity Varies Strongly With Particle Sizementioning

confidence: 96%

Systematic characterization and fluorescence threshold strategies for the wideband integrated bioaerosol sensor (WIBS) using size-resolved biological and interfering particles

et al. 2017

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Abstract. Atmospheric particles of biological origin, also referred to as bioaerosols or primary biological aerosol particles (PBAP), are important to various human health and environmental systems. There has been a recent steep increase in the frequency of published studies utilizing commercial instrumentation based on ultraviolet laser/light-induced fluorescence (UV-LIF), such as the WIBS (wideband integrated bioaerosol sensor) or UV-APS (ultraviolet aerodynamic particle sizer), for bioaerosol detection both outdoors and in the built environment. Significant work over several decades supported the development of the general technologies, but efforts to systematically characterize the operation of new commercial sensors have remained lacking. Specifically, there have been gaps in the understanding of how different classes of biological and non-biological particles can influence the detection ability of LIF instrumentation. Here we present a systematic characterization of the WIBS-4A instrument using 69 types of aerosol materials, including a representative list of pollen, fungal spores, and bacteria as well as the most important groups of non-biological materials reported to exhibit interfering fluorescent properties. Broad separation can be seen between the biological and non-biological particles directly using the five WIBS output parameters and by taking advantage of the particle classification analysis introduced by Perring et al. (2015). We highlight the importance that particle size plays on observed fluorescence properties and thus in the Perring-style particle classification. We also discuss several particle analysis strategies, including the commonly used fluorescence threshold defined as the mean instrument background (forced trigger; FT) plus 3 standard deviations (σ ) of the measurement. Changing the particle fluorescence threshold was shown to have a significant impact on fluorescence fraction and particle type classification. We conclude that raising the fluorescence threshold from FT + 3σ to FT + 9σ does little to reduce the relative fraction of biological material considered fluorescent but can significantly reduce the interference from mineral dust and other non-biological aerosols. We discuss examples of highly fluorescent interfering particles, such as brown carbon, diesel soot, and cotton fibers, and how these may impact WIBS analysis and data interpretation in various indoor and outdoor environments. The performance of the particle asymmetry factor (AF) reported by the instrument was assessed across particle types as a function of particle size, and comments on the reliability of this parameter are given. A comprehensive online supplement is provided, which includes size distributions broken down by fluorescent particle type for all 69 aerosol materials and comparing threshold strategies. Lastly, the study was designed to propose analysis strategies that may be useful to the broader community of UV-LIF instrumentation users in order to promote deeper discussions about how best to continue i...

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Section: Fluorescence Intensity Varies Strongly With Particle Sizementioning

confidence: 96%

Systematic characterization and fluorescence threshold strategies for the wideband integrated bioaerosol sensor (WIBS) using size-resolved biological and interfering particles

et al. 2017

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“…Mice were exposed to NMII or NMI in PBS or PBS alone using a liquid sparging aerosolizer (20). This apparatus ensures a uniform dose of bacteria to the lower airways through a nose-only aerosol exposure.…”

Section: Methodsmentioning

confidence: 99%

Coxiella burnetii Interaction with Neutrophils and Macrophages In Vitro and in SCID Mice following Aerosol Infection

2013

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Coxiella burnetii is an obligate intracellular bacterium that causes acute and chronic Q fever in humans. Human Q fever is mainly transmitted by aerosol infection. However, there is a fundamental gap in the knowledge regarding the mechanisms of pulmonary immunity against C. burnetii infection. This study focused on understanding the interaction between C. burnetii and innate immune cells in vitro and in vivo. Both virulent C. burnetii Nine Mile phase I (NMI) and avirulent Nine Mile phase II (NMII) were able to infect neutrophils, while the infection rates were lower than 29%, suggesting that C. burnetii can infect neutrophils, but infection is limited. Interestingly, C. burnetii inside neutrophils can infect and replicate within macrophages, suggesting that neutrophils cannot kill C. burnetii and C. burnetii may be using infection of neutrophils as an evasive strategy to infect macrophages. To elucidate the mechanisms of the innate immune response to C. burnetii natural infection, SCID mice were exposed to aerosolized C. burnetii. Surprisingly, neutrophil influx into the lungs was delayed until day 7 postinfection in both NMI-and NMII-infected mice. This result suggests that neutrophils may play a unique role in the early immune response against aerosolized C. burnetii. Studying the interaction between C. burnetii and the innate immune system can provide a model system for understanding how the bacteria evade early immune responses to cause infection.

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“…In addition, SCID mice receiving 300 g of control IgG2a or phosphate-buffered saline (PBS) were used as negative controls. All mice were exposed to virulent NMI using a liquid sparging aerosolizer (20). This apparatus ensures a uniform dose of bacteria to the lower airways through a nose-only aerosol exposure.…”

Section: Methodsmentioning

confidence: 99%

Characterization of a Lipopolysaccharide-Targeted Monoclonal Antibody and Its Variable Fragments as Candidates for Prophylaxis against the Obligate Intracellular Bacterial Pathogen Coxiella burnetii

et al. 2014

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Our previous study demonstrated that treatment of Coxiella burnetii with the phase I lipopolysaccharide (PI-LPS)-targeted monoclonal antibody (MAb) 1E4 significantly inhibited C. burnetii infection in mice, suggesting that 1E4 is a protective MAb. To determine whether passive transfer of antibodies (Abs) can provide protection against C. burnetii natural infection, we examined if passive transfer of 1E4 would protect SCID mice against C. burnetii aerosol infection. The results indicated that 1E4 conferred significant protection against aerosolized C. burnetii, suggesting that 1E4 may be useful for preventing C. burnetii natural infection. To further understand the mechanisms of 1E4-mediated protection and to test the possibility of using humanized 1E4 to prevent C. burnetii infection, we examined whether the Fab fragment of 1E4 (Fab1E4), a recombinant murine single-chain variable fragment (muscFv1E4), and a humanized single-chain variable fragment (huscFv1E4) retained the ability of 1E4 to inhibit C. burnetii infection. The results indicated that Fab1E4, muscFv1E4, and huscFv1E4 were able to inhibit C. burnetii infection in mice but that their ability to inhibit C. burnetii infection was lower than that of 1E4. In addition, treatment of C. burnetii with Fab1E4, muscFv1E4, or huscFv1E4 can block C. burnetii infection of macrophages. Interestingly, treatment of C. burnetii with huscFv1E4 can significantly reduce C. burnetii infectivity in human macrophages. This report provides the first evidence to demonstrate that the humanized variable fragments of an LPS-specific MAb can neutralize C. burnetii infection and appears to be a promising step toward the potential use of a humanized MAb as emergency prophylaxis against C. burnetii exposure.

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Design and performance of a single-pass bubbling bioaerosol generator

Cited by 50 publications

References 13 publications

Systematic characterization and fluorescence threshold strategies for the wideband integrated bioaerosol sensor (WIBS) using size-resolved biological and interfering particles

Systematic characterization and fluorescence threshold strategies for the wideband integrated bioaerosol sensor (WIBS) using size-resolved biological and interfering particles

Coxiella burnetii Interaction with Neutrophils and Macrophages In Vitro and in SCID Mice following Aerosol Infection

Characterization of a Lipopolysaccharide-Targeted Monoclonal Antibody and Its Variable Fragments as Candidates for Prophylaxis against the Obligate Intracellular Bacterial Pathogen Coxiella burnetii

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