Bioaerosol

About: Bioaerosol is a research topic. Over the lifetime, 1347 publications have been published within this topic receiving 34791 citations.

Monitoring of bacterial pathogens at workplaces in power plant using biochemical and molecular methods.

Abstract: The aim of this study was to characterize the ways of spreading of the most common bacterial species isolated from workers as well as from the air and raw materials at the workplaces in power plant utilizing biomass sources. To monitor microbial transmission and identify the source of contamination in the working environment, a combination of molecular and biochemical methods was applied. The study was carried out at workplaces in power plant utilizes biomass as a main fuel source. At each of the studied workplaces, bioaerosol particles were collected on sterile Teflon filters using personal conical inhalable samplers (CIS), and biomass samples (straw pellets and briquettes, corn briquettes, sunflower pellets and wood chips) were directly taken from their storage places. Simultaneously with that, the swab samples from the hands of ten workers and their used respiratory masks (of FFP2 class) were also collected after the work shift to evaluate individual workers’ microbial contamination. In all collected samples, total bacterial concentrations were assessed and the most common microbial isolates were identified to the species level using both biochemical (API tests) and molecular polymerase chain reaction (PCR), followed by random amplification of polymorphic DNA (RAPD) typing methods. The mean concentrations of culturable bacteria in the air and in biomass samples at the studied workplaces were high, i.e. 1.2 × 106cfu/m3 and 3.8 × 104cfu/g, respectively. The number of bacteria in the swab and mask samples also reached a high level of 1.4 × 104 cfu/ml and 1.9 × 103 cfu/cm2, respectively. Among the most frequently isolated microorganisms from all types of samples were Gram-positive bacteria of the genus Bacillus and Staphylococcus xylosus. 37 bacterial strains belonging to the genus Bacillus (B. licheniformis 8, B. pumilus 15 and B. subtilis 4) and Staphylococcus (10) were genotyped by the RAPD-PCR method. Based on RAPD-PCR analyses, the genomic similarity among 19 Bacillus strains isolated from biomass, air, protective mask and hand samples as well as 6 S. xylosus strains isolated from air, mask and hand samples exceeded 80%. This study demonstrated that biomass is the primary source of bacteria at power plant workplaces. These results also revealed that biomass-associated bacteria can be easily transferred to workers’ hands and mask during their routine activities. To improve health protection at the workplaces, adequate training courses on hand hygiene and how to use and remove respiratory masks correctly for workers should be introduced as a key element of the prevention strategy. From the occupational point of view, the PCR-based methods seem to be an efficient tool for a fast and precise typing of bacterial strains isolated from different sources in the occupational environment. Such methods may help to implement appropriate prophylactic procedures and minimize transmission of infectious agents at workplaces.

Spatio-temporal characterisation of bioaerosols at diverse outdoor land-use sites in an urban environment

Abstract: The land-use configuration has huge impact on emission sources and also a major influencing factor, which ultimately determine the microbial count, composition and seasonal dynamics of bioaerosols at respective site. Despite this, very few studies compare bioaerosols exposure at different land-use sites. The aim of the present study was to measure and compare the aerosolised bacterial and fungal counts across seasons using active Anderson cascade impactor at different land-use configurations in an urban metropolitan. The counts of aerosolised bacteria and fungi were estimated across five seasons of a tropical climate. A mixed-effect model showed that the season and land-use configuration have a bearing on microbial counts. Season and land use interact in a complex manner to produce bioaerosol count variability. Meteorological parameter (temperature and relative humidity) had a significant effect on microbial counts at all land-use configurations, but they could not fully explain variations of microbial counts in the mixed model.

Laboratory and field characterisation of fluorescent and primary biological aerosol particles

Abstract: Primary biological aerosol (PBA) particles include bacteria, fungal spores, pollen and animal and plant debris. They are ubiquitous in the atmosphere and form a transmission vector for animal and plant disease. Several studies also suggest PBA are important in cloud ice processes despite being present at relatively low concentrations. Biodiversity changes caused by human activity may therefore have climate impacts through cloud-aerosol interactions, and improved methods are required to characterise PBA size distributions, sources and sinks on a global scale.Natural and anthropogenic sources contribute PBA while several processes remove it from the atmosphere. It therefore exhibits strong temporal and geographical variations in concentration. Published measurements involve several collection and offline analysis techniques, which are difficult to compare directly and generally feature low time resolution. This means PBA are poorly characterised globally and specific meteorological influences are difficult to identify. Light-induced fluorescence (LIF) offers a rapid, consumable-free method of measuring PBA size distributions, however false-positive results can contribute outdoors and LIF cannot resolve specific biological species.This thesis describes the use of a Wide Issue Bioaerosol Spectrometer version 3 (WIBS-3): a novel LIF instrument that records particle diameter, shape and fluorescence following excitations at two wavelengths. Its response to samples of PBA, non-PBA and calibration particles was assessed in the laboratory, and three outdoor studies are discussed at length: Below and above a tropical rainforest canopy (Malaysia); in an urban location (Manchester); and at a high-altitude background site (Puy de D�me, France). The likely sources of fluorescent aerosol are identified at each site: Fungal spore release was triggered by rainfall in Borneo; increased fluorescent concentrations were linked to traffic activity in Manchester and a strong diurnal cycle in France was attributed to boundary layer depth. The limitations and benefits of the different WIBS-3 measurement channels are also discussed, along with comparisons of fluorescent particle concentrations with published and in-situ PBA measurements.False-positives are found to play a strong role outdoors away from PBA sources such as tropical forest, and a ubiquitous background of fluorescent non-PBA was detected using one excitation wavelength. A shorter excitation wavelength appears more capable of discriminating between PBA and false-positives. Basic PBA emission rates are calculated using data from these studies and tropical rainforests are concluded to be the largest source of PBA mass globally.

Spatiotemporal Variations of Bioaerosols in the Vicinity of an Animal Feeding Operation Facility in the US

Abstract: Bioaerosol emissions from animal feeding operation (AFO) facilities are of increasing interest due to the magnitude of the emissions and their potential health effect on local communities. There is limited information about fate and transport of AFO bioaerosol emissions. In this study, concentrations of airborne bacteria and fungi were measured at four ambient stations in four wind directions surrounding an egg production farm through winter, spring and summer using Andersen six-stage samplers. Mean concentrations of ambient bacteria and fungi ranged from 8.7 × 102 CFU m-3 to 1.3 × 103 CFU m-3 and from 2.8 × 102 CFU m-3 to 1.4 × 103 CFU m-3, respectively. Ambient bacterial concentrations were not significantly different over the seasons, while ambient fungal concentrations were the highest in summer and the lowest in winter. There were significant differences between downwind and upwind bacterial concentrations (p < 0.0001). Downwind bacterial and fungal concentrations responded differently to the influencing factors. Bacterial concentrations were quadratically correlated with wind vector (combined effects of wind speed and direction) and emission rate, were positively correlated with temperature, and were negatively correlated with solar radiation. Fungal concentrations were positively correlated with temperature, RH, and emission rate, and were negatively correlated with wind vector.

NaCl-amendment assay targeting airborne bacteria in tropospheric bioaerosols transported by westerly wind over Noto Peninsula

Abstract: Bioaerosol particles including bacteria, fungi, and virus are originated from marine and terrestrial environments. The airborne microorganisms are transported for long distance through the free troposphere and are thought to influence the downwind ecosystems and human life. However, microbial communities in the free troposphere have not been understood in detail because the direct sampling of microbial cells at high altitude requires sophisticated sampling techniques. In this study, for the investigation of microbial species compositions in the free troposphere, air sampling using an aircraft was performed over the Noto Peninsula in Japan, where the tropospheric winds carry aerosol particles from continental areas. Two air samples were collected at 3,000 m on March 27, 2010, when air mass was carried from the Gobi Desert to Japan area. Microorganisms from one air sample grew in culture media containing up to 15 % NaCl, suggesting that halotolerant bacteria maintain their viabilities in the free troposphere. DGGE analysis revealed that the amended cultures were dominated by Bacillus subtilis, and the isolates obtained from the amended cultures were identical to B. subtilis. Furthermore, the 16S rDNA clone library (culture-independent survey) of the other air sample grew was composed of three phylotypes belonging to Firmicutes, Bacteroidetes, and Proteobacteria with the sequences of Firmicutes phylotype corresponding to that of the cultured B. subtilis sequence. Microscopic observation using FISH method indicated that B. subtilis particles occupied 80 % of total eubacterial particles on the mineral particles. The halotolerant bacteria identical to B. subtilis would dominate at high altitudes over Noto Peninsula where the prevailing westerly wind was blowing.