Volumetric Air Sampler Research Articles

Method for a homogeneous distribution of pollens in an environmental exposure chamber.

A variety of different environmental exposure chambers (EECs) have been used to evaluate treatments for allergic rhinitis. To describe and test a system for a homogenous distribution of grass pollen, Phleum Pratense, in an EEC to be used for controlled pollen exposure studies in allergic participants. A chamber made of stainless steel with completely rounded corners, seating four individuals at a time, was used. Room pressure, temperature, humidity and the air change rate were kept constant throughout the study period. A rotating pipette dispensed a uniform supply of pollen into a turntable's v-shaped grooves. A stainless steel capillary tube sucked the pollens into a venturi throat at which time the pollens were mixed with a high-pressure airstream of compressed high-efficiency particulate arrestance filtered air and then transported to a spreading plate inside the EEC. To achieve uniform concentrations in the EEC, the turntable's rotating speed was continuously adjusted using information from video-coupled feedback and feed forward mechanisms. Pollen levels were detected using standard volumetric air samplers and laser particle counters. The target pollen exposure level was 1000 pollens/m(3) . Twenty-one participants were exposed to pollens in the EEC twice for 210 min. Participants evaluated their symptoms every 30 min using a total nasal symptom score (TNSS) consisting of blocked nose, runny nose, nasal itching and sneezing. Across fifteen study days, the average pollen level was 982 pollens/m(3) (SD, 102 pollens/m(3) ). On average, participants experienced a 10% difference in overall pollen levels between their two visits to the EEC. The mean TNSSs rose throughout the exposure period, with a low at baseline of 0.43 (SD, 0.68) to a high of 4.71 (SD, 2.43) just before exiting the EEC. This EEC provides a reproducible, precise and homogenous distribution of pollens making it suitable for single-centre allergy clinical trials.

Madeira—a tourist destination for asthma sufferers

Madeira Island is a famous tourist destination due to its natural and climatic values. Taking into account optimal weather conditions, flora richness and access to various substrates facilitating fungal growth, we hypothesised a very high risk of elevated fungal spore and pollen grain concentrations in the air of Funchal, the capital of Madeira. Concentration levels of the most allergenic taxa were measured from 2003 to 2009, using a 7-day volumetric air sampler, followed by microscopy analysis. Dependence of bioaerosols on the weather conditions and land use were assessed using spatial and statistical tools. Obtained results were re-visited by a comparison with hospital admission data recorded at the Dr. Nélio Mendonça Hospital in Funchal. Our results showed that despite propitious climatic conditions, overall pollen grain and fungal spore concentrations in the air were very low and did not exceed any clinically established threshold values. Pollen and spore peak concentrations also did not match with asthma outbreaks in the winter. Identification of places that are "free" from biological air pollution over the summer, such as Madeira Island, is very important from the allergic point of view.

The characteristics of indoor and outdoor fungi and their relation with allergic respiratory diseases in the southern region of Turkey.

Indoor and outdoor fungal exposure has been shown to be associated with the development of allergic respiratory diseases. The aim of the study was to investigate the types and concentrations of airborne fungi inside and outside homes and evaluate the association between fungal levels and allergic diseases in the southern region of Turkey. A total of 61 children admitted with respiratory complaints to the pediatric allergy clinic between September 2007 and November 2008 were included in this study. The air samples were obtained using the Air IDEAL volumetric air sampler longitudinally for 1year. A comprehensive questionnaire was used for medical history and housing conditions. Skin prick test was performed to determine fungal sensitivity and spirometric indices were employed. The predominant indoor fungal species were Cladosporium (69.3%), Penicillium (18.9%), Aspergillus (6.5%), and Alternaria (3.1%). A strong correlation between indoor and outdoor fungal levels was detected for the Cladosporium species (p < 0.001, r = 0.72) throughout the year. Living in a detached home (p = 0.036) and the presence of cockroaches (p = 0.005) were associated with total indoor fungal levels. The presence of cockroaches (aOR 3.5; 95% CI 0.95-13.10, p = 0.059) was also associated with fungal sensitization at the edge of significance. The statistical cutoff values of indoor and outdoor Cladosporium levels to predict symptomatic asthma were found to be >176CFU/m(3) (p = 0.003, AUC 0.696; sensitivity 65.5%; specificity 68.7%) and >327CFU/m(3) (p = 0.038; AUC 0.713; sensitivity 66.6%; specificity 76.9%), respectively. Children with respiratory symptoms are exposed to a considerable level of fungi inside and outside their homes. The prevention of fungal exposure may provide valuable intervention for respiratory diseases.

An analysis of local wind and air mass directions and their impact on Cladosporium distribution using HYSPLIT and circular statistics

Ecological studies that examine species-environment relationships are often limited to several meteorological parameters, i.e. mean air temperature, relative humidity, precipitation, vapour pressure deficit and solar radiation. The impact of local wind, its speed and direction are less commonly investigated in aerobiological surveys mainly due to difficulties related to the employment of specific analytical tools and interpretation of their outputs. Identification of inoculum sources of economically important plant pathogens, as well as highly allergenic bioaerosols like Cladosporium species, has not been yet explored with remote sensing data and atmospheric models such as Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT). We, therefore, performed an analysis of 24 h intra-diurnal cycle of Cladosporium spp. spores from an urban site in connection with both the local wind direction and overall air mass direction computed by HYSPLIT. The observational method was a volumetric air sampler of the Hirst design with 1 h time resolution and corresponding optical detection of fungal spores with light microscopy. The atmospheric modelling was done using the on-line data set from GDAS with 1° resolution and circular statistical methods. Our results showed stronger, statistically significant correlation (p ≤ 0.05) between high Cladosporium spp. spore concentration and air mass direction compared to the local wind direction. This suggested that a large fraction of the investigated fungal spores had a regional origin and must be located more than a few kilometers away from the sampling point.

Potential impact of climate change on fungal distributions: analysis of 2 years of contrasting weather in the UK

The impact of climate change on fungal growth and spore production is less well documented than for allergenic pollen grains, although similar implications for respiratory tract diseases in humans occur. Fungal spores are commonly described as either “dry” or “wet” according to the type of weather associated with their occurrence in the air. This study examined the distribution of selected fungal spores (Alternaria spp., Cladosporium spp., Didymella spp., Epicoccum spp., Leptosphaeria spp. and rusts) occurring in the West Midlands of UK during 2 years of contrasting weather. Spore specimens were collected using a 7-day volumetric air sampler and then analysed with the aid of light microscopy. Distributions of spores were then studied using normality tests and Mann–Whitney U test, while relationships with meteorological parameters were investigated using Spearman’s rank test and angular-linear correlation for wind direction analysis. Our results showed that so-called wet spores were more sensitive to the weather changes showing statistically significant differences between the 2 years of study, in contrast to “dry” spores. We predict that in following years we will observe accelerated levels in allergenic fungal spore production as well as changes in species diversity. This study could be a starting point to revise the grouping system of fungal spores as either “dry” or “wet” types and their response to climate change

Airborne basidiospores of Coprinus and Ganoderma in a Caribbean region

The present study sought to examine Coprinus and Ganoderma airborne spore counts, analysing seasonal variations, the influence of meteorological variables and intraday behaviour with a view to charting the aerobiological dynamics of both genera in Havana (Cuba) during a 2-year period (November 2010–October 2012). A Hirst-type volumetric air sampler was used as sampling methodology. The spores registered in the air were identified and counted following the model proposed by the Spanish Aerobiological Network based on two longitudinal transects along the slides. Coprinus spores outnumbered those of the Ganoderma (28,468 annual total spores vs. 1,921 spores). Moreover, both genera were recorded in the atmosphere on a large number of days over the two-year study period, with daily maximum concentrations in the rainy months. The daily maximum value for Coprinus was 880 spores/m3 (30 September 2011), whereas for Ganoderma 44 spores/m3 (4 September 2011). The analysis of the Spearman correlation coefficient showed a significant positive correlation of the airborne Coprinus and Ganoderma spores with the temperature, relative humidity and rainfall, whereas the degree of association is negative with the wind speed. Regarding the intraday behaviour, both basidiospores were more abundant in the atmosphere during the night, with a maximum peak at 5–6 a.m.

139 Evidence of Pseudomonas aeruginosa super-shedding from individual patients leading to airborne dissemination in a UK CF centre

Objectives: The extent and mechanism of cross-infection with Pseudomonas aeruginosa (PA) in specialist cystic fibrosis (CF) units remain controversial. Prevention of droplet spread by segregation and use of single patient rooms is advised by most authorities. Despite these measures, many centres continue to report outbreaks of clonal “epidemic” strains. We conducted an aerobiological study to examine airborne dispersal of PA in a large CF centre in the UK. Methods: Microbiological air sampling was conducted in outpatient and inpatient areas inhabited by patients known to harbour the Liverpool Epidemic Strain (LES) of PA. A volumetric air sampler was placed at least 1m from patients, working at a rate of 100 L/min with a sampling time of 10min. Any colonies growing on Pseudomonas selective agar were identified by phenotypic and molecular methods and the number of colony-forming units (CFUs) counted. Conclusion: Out of 177 samples obtained from 8 separate patient environments, 33 (19%) grew PA. Contamination was greater in patient rooms than corridor areas; 23% (29/125) vs 10% (4/51) respectively. Rooms inhabited by 3 of 8 patients yielded positive growth. Corridor air was positive in the vicinity of 1 patient’s closed room. Samples from this patient’s room demonstrated much higher counts than those from other rooms (mean 61CFU/m3 vs 0−3CFU/m3). These data confirm that PA can contaminate air >1m from patients and suggest that certain patients may act as “super-shedders”. Ventilation strategies and infection control precautions in CF centres should take into account the possibility of true airborne transmission of PA.

140 Population structure of Pseudomonas aeruginosa and the prevalence of epidemic clones in patients with cystic fibrosis over four years

Objectives: The extent and mechanism of cross-infection with Pseudomonas aeruginosa (PA) in specialist cystic fibrosis (CF) units remain controversial. Prevention of droplet spread by segregation and use of single patient rooms is advised by most authorities. Despite these measures, many centres continue to report outbreaks of clonal “epidemic” strains. We conducted an aerobiological study to examine airborne dispersal of PA in a large CF centre in the UK. Methods: Microbiological air sampling was conducted in outpatient and inpatient areas inhabited by patients known to harbour the Liverpool Epidemic Strain (LES) of PA. A volumetric air sampler was placed at least 1m from patients, working at a rate of 100 L/min with a sampling time of 10min. Any colonies growing on Pseudomonas selective agar were identified by phenotypic and molecular methods and the number of colony-forming units (CFUs) counted. Conclusion: Out of 177 samples obtained from 8 separate patient environments, 33 (19%) grew PA. Contamination was greater in patient rooms than corridor areas; 23% (29/125) vs 10% (4/51) respectively. Rooms inhabited by 3 of 8 patients yielded positive growth. Corridor air was positive in the vicinity of 1 patient’s closed room. Samples from this patient’s room demonstrated much higher counts than those from other rooms (mean 61CFU/m3 vs 0−3CFU/m3). These data confirm that PA can contaminate air >1m from patients and suggest that certain patients may act as “super-shedders”. Ventilation strategies and infection control precautions in CF centres should take into account the possibility of true airborne transmission of PA.

Effect of The Presence of Ivory Coconut (Cocos nucifera L) to Decrease Particulate Matter Concentration in Bogor Agricultural University

Demands and technology developed significantly, that cause human activities more varied and dense. To sufficient human needs, there was uncontrolled nature exploitation without thinking ecosystem balance. That effect degradation of air quality ambient. The first objection of this experiment was knowing effect of the presence of Ivory Coconut (Cocos nucifera L) to reduce particulate concentration, the second was knowing effect of wind flow rate to particulate distribution from emission sources, the third was knowing relation between total vehicle and the decrease of particulate concentration, and the fourth was effect of Ivory Coconut to environmental temperature. The information can be used to guarantee human health. Sampling held in Monday, October 15th 2012 from 13.00 until 14.00 WIB at Faculty of Agriculture parking area, Bogor Agricultural University. And the analysis held in air quality laboratory, Department of Civil and Environmental Engineering, Bogor Agricultural University. The instrument used High Volumetric Air Sampler and Gravimetric Method. From the experiment resulted particulate concentrated produced by vehicles was 137.742μg/m3 and particulate concentration measurable under Ivory Coconut (Cocos nucifera L) was 111.090μg/m3. The conclusion was Ivory Coconut can reduce particulate concentration in ambient air in the amount of 19.350%.

Particle counting and microbiological air sampling: Results of the simultaneous use of both procedures in different types of hospital rooms

IntroductionIn order to assess the relationship between the concentrations of airborne fungi and particles, particle counting was combined with fungal air sampling in several rooms of a hospital. MethodsConcentrations of ≥0.5μm particles (P05) and ≥1μm particles (P1) were measured using a particle counter; fungal air sampling was performed with volumetric air samplers, which impacted air on Rodac plates with Sabouraud chloramphenicol agar. Particle counts were categorised according to ISO 14644-1 standard cut-off points; their association with fungal detection was assessed with Fisher's exact test. ResultsForty-two simultaneous samplings were carried out: 24 in operating rooms, 13 in rooms for burns or haematology patients, 3 in pharmacy clean rooms, and two in other procedure rooms. Filamentous fungi were recovered in 5 samples, which also had higher particle counts. No fungi were detected in 12 samplings with both P05 and P1 concentrations below the maximum for class 6 clean rooms; 4 of 7 samplings with both concentrations within the range for class 8 clean rooms were positive for fungi. The association between fungal detection and higher particle counts was statistically significant, both for P05 (p=.004) and P1 (p=.003). There was a partial overlap between the concentrations of particles of samplings which were positive or negative for fungi. ConclusionsThere is a relationship between the concentrations of P05 and P1 and airborne fungi in hospital rooms. When both P05 and P1 concentrations are below the maximum for class 6 clean rooms, a negative fungal detection can be predicted.

Pollination Dynamics inVitis viniferaL.

Vitis vinifera pollen dispersal was studied using volumetric air samplers situated within a vineyard to measure airborne pollen concentration. The pollen dispersal period of Cabernet Sauvignon was seven days, reaching daily mean concentrations of about 90 grains/m3, with peak pollen dispersal near midday. Daily and hourly variations in concentration were positively correlated with temperature but negatively with relative humidity. Concentration was greatest within 1.5 m of the plants and up to 1 m aboveground, after which it diminished.

Indoor Fungal Concentration in the Homes of Allergic/Asthmatic Children in Delhi, India

Allergy to fungi has been linked to a wide range of illnesses, including rhinitis and asthma. Therefore, exposure to fungi in home environment is an important factor for fungal allergy. The present study was aimed to investigate types of airborne fungi inside and outside the homes of asthmatic children and control subjects (nonasthmatic children). The dominant fungi were evaluated for their quantitative distribution and seasonal variation. The air samples were collected from indoors and immediate outdoors of 77 selected homes of children suffering from bronchial asthma/allergic rhinitis using Andersen volumetric air sampler. The isolated fungal genera/species were identified using reference literature, and statistical analysis of the dominant fungi was performed to study the difference in fungal concentration between indoor and immediate outdoor sites as well as in between different seasons. A total of 4423 air samples were collected from two indoor and immediate outdoor sites in a 1-year survey of 77 homes. This resulted in the isolation of an average of 110,091 and 107,070 fungal colonies per metric cube of air from indoor and outdoor sites, respectively. A total of 68 different molds were identified. Different species of Aspergillus, Alternaria, Cladosporium, and Penicillium were found to be the most prevalent fungi in Delhi homes, which constituted 88.6% of the total colonies indoors. Highest concentration was registered in autumn and winter months. Total as well as dominant fungi displayed statistically significant differences among the four seasons (p < 0.001). The largest number of isolations were the species of Aspergillus (>40% to total colony-forming units in indoors as well as outdoors) followed by Cladosporium spp. Annual concentration of Aspergillus spp. was significantly higher (p < 0.05) inside the homes when compared with outdoors. Most of the fungi also occurred at a significantly higher (p < 0.001) rate inside the homes when compared with immediate outdoors. Asthmatic children in Delhi are exposed to a substantial concentration of mold inside their homes as well as immediate outdoor air. The considerable seasonal distributions of fungi provide valuable data for investigation of the role of fungal exposure as a risk for respiratory disorders among patients suffering from allergy or asthma in Delhi.

Risk Assessment Methods for the Ringspot Pathogen Mycosphaerella brassicicola in Vegetable Brassica Crops.

Mycosphaerella brassicicola causes ringspot on Brussels sprouts, which can result in substantial yield loss in commercial production. Brussels sprout buttons are downgraded if this pathogen occurs on them. In this study, the effect of temperature and wetness duration was investigated on infection of Brussels sprouts using controlled environments (CE). The effect of temperature and wetness duration on inoculum production and ascospore discharge was also investigated. Infection by M. brassicicola was described using a mathematical model and was compared to estimates of ascospore availability obtained via a volumetric air sampler and immunofluorescence (IF). Infection of M. brassicicola was correlated (r = 0.92) with temperature during leaf wetness periods. The relationship between temperature and time to discharge of 5 and 50% of the cumulative total number of ascospores from ringspot lesions was r = 0.99 and 0.98, respectively (P < 0.001). In field experiments, an optimal wind run (the product of the average wind speed and the period over which that average speed was measured) of 250 to 500 km day-1 was required for the dissemination of ringspot inoculum to field bait plants. Quantification of M. brassicicola inoculum in collected field aerosols was possible using a monoclonal antibody in a plate-trapped antigen enzyme-linked immunosorbent assay. Precoating of the air sampler wells with sodium azide prevented trapped spores from germinating. Ringspot inoculum could be detected and quantified in air samples from commercial crops of Brussels sprouts in the United Kingdom. Low levels of ringspot inoculum measured within crops did not lead to disease development.

Evaluation of the efficiency of the Coriolis air sampler for pollen detection in South Europe

The Coriolis δ air sampler is a new volumetric air sampler, dedicated to outdoor monitoring of airborne biological particles, including pollen and spores. In the present work, the performance of the Coriolis in the collection of pollen grains was evaluated in comparison with a Hirst spore trap, the most frequently used trap in aerobiological studies, in two cities of South Europe, Evora (Portugal) and Cordoba (Spain). Both concentration values are compared, and statistical analysis was carried out. The present study indicated that, in general, pollen counts for all taxa detected with the Hirst trap were higher than those detected with the Coriolis δ in both cities. In Cordoba, significant differences were detected for all taxa except for Cupressus, Olea and Pinus, while in Evora significant differences were noted for all except Pinus and Poaceae. Differences were particularly marked in species flowering during April and May. In spite of theses differences, Spearman correlation test results showed that the relationship between Hirst and Coriolis curves was always positive and significant (p > 0.01). Regards to the number of detected taxa, the results showed greater diversity for the Hirst sampler in both cities.

Surveillance of fungal allergic sensitization using the fluorescent halogen immunoassay

OBJECTIVE: Conidia derived from a small number of common fungal genera are widely accepted as the etiological agents responsible for fungal allergic sensitization. The contribution of fungal conidia, spores, airborne hyphae, and subcellular fragments from other uncharacterized fungal genera remains unclear. In this proof-of-concept study, we examined the composition of mycoaerosols that atopic women were exposed and sensitized to in their own indoor environment using the fluorescent halogen immunoassay (fHIA). PATIENTS AND METHODS: Mycoaerosols were collected onto mixed cellulose ester protein binding membranes (PBMs) for 30 minutes with volumetric air sampling pumps. The PBMs were laminated with an adhesive cover slip and indirectly immunostained with individual patient serum IgE using the fHIA. Samples were examined using confocal laser scanning microscopy and immunostained particles were expressed as a percentage of total particles. RESULTS: All air samples contained a broad spectrum of fungal spores, conidia, hyphae, and other fungal particulates. Airborne concentrations varied between individual study participant environments. Positively immunostained conidia belonging to moniliaceous amerospores, Cladosporium, Alternaria, and many unknown species were observed in the majority of air samples. Other fungal genera including Bipolaris, Curvularia, Pithomyces, and Stachybotrys, in addition to, ascospore genera and dematiaceous hyphal fragments released detectable allergen. Twelve percent of all fHIA haloes quantified in the analysis were directed towards fungal particles. No immunostaining was detected to conidia belonging to Epicoccum, Fusarium, and Spegazzinia species. CONCLUSION: In addition to characterized fungal aeroallergens, we observed a wider composition of fungi that bound human IgE. Field surveillance studies that utilize immunodiagnostic techniques such as the fHIA will provide further insight into the diversity of fungi that function as aeroallergen sources in individual study participant environments.

Analysis of the potential fungal biodeteriogen effects in the “Doctorate Library” of the University of Perugia, Italy

Historical collections held in ancient archives and libraries constitute a cultural and artistic heritage of inestimable value. These collections contain a series of organic materials which may alter and perish in time, especially if they are conserved in inadequate environmental conditions and without any specific precautionary devices to protect them from damage caused by chemical, biological and physical factors. It is essential to prevent ‘at risk’ situations to conserve library and archive heritage. Early detection of fungal spores and moulds in conservation environments will permit us to intervene at the infection site at the right moment and also to detect the micro‐environments where climatic parameters are not suitable for conservation purposes. The aim of this study is to examine potentially biodeteriogen fungal micro‐flora in the environment of the “Doctorate Library”, one of the most important buildings of the University of Perugia, which contains frescos and library collection of great value. The study was carried out through quantitative and qualitative analysis of airborne fungal species and through the evaluation of viable aerobiological particles as potential agents of biodeterioration. The airspore monitoring was made using the active method (by Personal Volumetric Air Sampler Spore Trap, Burkard Company Ltd.) and the passive one (by sedimentation technique on Petri dishes). The results obtained by both methods allowed us to detect numerous potentially biodeteriogen species, to determine their quantity and influence and to evaluate the levels of their variability in time.

A comparative study on the airborne fungi in Athens, Greece, by viable and non-viable sampling methods

Airborne fungi were studied in the city of Athens using two complementary methods in which 136 concurrent samplings were carried out during the 12-month period from January until December 1998. A portable Burkard air sampler for agar plates was used for trapping the culturable portion of the mycobiota. Nineteen genera of fungi were identified and assessed in terms of total numbers and fluctuations in concentration (Alternaria, Arthrinium, Aspergillus, Aureobasidium, Botrytis, Chrysonilia, Cladosporium, Drechslera, Epicoccum, Fusarium, Mucor, Nigrospora, Paecilomyces, Penicillium, Rhizopus, Sclerotinia, Scopulariopsis, Trichoderma and Ulocladium), with the exception of those included in the Sphaeropsidales, the yeasts, and the non-sporulating fungi, which were counted as groups. A volumetric Burkard air sampler for glass slides was operating simultaneously for detecting the total mycobiota, including the non-culturable and the non-viable portion. Ascospores, basidiospores, spores of Myxomycetes, Ustilaginales, Uredinales and Erysiphales, teliospores of Puccinia, as well as conidia of the genera Curvularia, Helminthosporium, Periconia, Pestalotiopsis, Pithomyces, Polythrincium, Stachybotrys, Stemphylium and Torula were also recorded. Only seven of the genera were recovered by both samplers. The total numbers of fungal spores, which had a maximum concentration of 3,175 spores/m3, as well as the spore concentrations of the genera Cladosporium (2,565 spores/m3) and Alternaria (280 spores/m3) were underestimated by the viable method (2,435 CFU/m3 for the total, 2,169 CFU/m3 for Cladosporium and 180 CFU/m3 for Alternaria). The non-viable method fails to resolve the identification of the genera Penicillium and Aspergillus, which are major components of the airborne mycobiota (1,068 CFU/m3 and 204 CFU/m3, respectively) based on recovery by the viable method.

Calendrier des spores fongiques de la Martinique

A survey of airborne mould spores in the atmosphere of the town of Fort de France was conducted with a seven-day recording volumetric spore trap (Burkard model) from July 1, 2003 to June 30, 2004. Among the many spore types recorded on the strips, the most common belonged to 5 genera ( Alternaria, Cladosporium, Curvularia, Pithomyces and Torula), 2 families (Aspergillaceae and Basidiomycetaceae), and 6 types (Myxomycetes, Helminthosporium, sterile mycelium, Ascospores and ‘Other spores’). At the same time, viable airborne propagules were isolated with a volumetric air sampler Air IDEAL ® (BioMérieux), onto a medium containing Rose Bengal with Chloramphenicol. The most frequently isolated moulds belonged to the following genera: Aspergillus (22.5%), Cladosporium (13.5%), Curvularia (9.3%), Penicillium (8.8%), Fusarium (7%), and sterile Mycelium (20%).

“Gesundheit!” Sneezing, Common Colds, Allergies, andStaphylococcus aureusDispersion

Staphylococcus aureus is among the most important pathogens in today's hospital setting. The effects of sneezing on the airborne dispersal of S. aureus and other bacteria were assessed in 11 healthy nasal S. aureus carriers with experimentally induced rhinovirus colds. Airborne dispersal was studied by volumetric air sampling in 2 chamber sessions with and without histamine-induced sneezing. After 2 days of preexposure measurements, volunteers were inoculated with a rhinovirus and monitored for 14 days. Daily quantitative nasal- and skin-culture samples for bacteria and nasal-culture samples for rhinovirus were obtained, cold symptoms were assessed, and volunteer activities were recorded during sessions. All participants developed a cold. Sneezing caused a 4.7-fold increase in the airborne dispersal of S. aureus, a 1.4-fold increase in coagulase-negative staphylococci (CoNS), and a 3.9-fold increase in other bacteria (P < .001). An additional 2.83 colony forming units (cfu) of S. aureus/m3/min, 3.24 cfu of CoNS/m3/min, and 474.61 cfu of other bacteria/m3/min were released per sneeze. Rhinovirus exposure did not change the frequency of sneezing or airborne dispersal. Having respiratory allergies increased the spread of S. aureus by 3.8-fold during sneezing sessions (P < .001). Nasal S. aureus carriers disperse a significant amount of S. aureus into the air by sneezing. Experimental colds do not alter bacterial dispersal, but respiratory allergies multiply the effect of dispersing S. aureus.

Dual fluorescent halogen immunoassay for bioaerosols using confocal microscopy

The need to measure bioaerosols has increased dramati-cally in recent years due to the growing incidence of respi-ratory diseases. Fungi are among the most commonbioaerosols that humans inhale and exposure to fungi indomestic and occupational environments has been associ-ated with adverse health eVects such as infections, allergies,mycotoxicoses, or irritations [1]. Numerous fungal speciesare known to produce virulence factors, mycotoxins, andallergens, but many of the fungi that occur naturally in theenvironment remain uncharacterized. This is partly due tothe tremendous diversity of fungal species in the environ-ment, the current lack of analytical methods for the detec-tion and characterization of fungal exposures, and theabsence of standardized fungal extracts for the develop-ment of immunodiagnostic assays.Many strategies have evolved to sample, identify, andinterpret fungal exposure; however, no strategy serves allpurposes, as exposure is a complex and dynamic processconfounded by spatial, temporal, and geographic variationsin airborne counts. Current techniques for fungal exposureassessment rely on sample cultivation or volumetric airsampling in combination with light microscopy [2]. How-ever, these techniques are often time consuming and subjec-tive and require mycological expertise. More recently,molecular techniques based on PCR and immunoassayshave been developed to overcome some of these limitations,although the quantiWcation of viable fungal particles stillremains a challenge [2].In our earlier work [3], we described the development ofan enzyme-based halogen immunoassay (HIA).