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Total seasonal ragweed is inversely correlated with seasonal rainfall
A Survey on Species of Aspergillus in the Atmosphere of Hospital Premises B. Vittal, N. Udaya Prakash; CAS in Botany, University of Madras, Chennai, INDIA. RATIONALE: Role of the fungus, Aspergillus in inducing Abstructive Broncho-Pulmonary Aspergillosis (ABPA), Aspergilloma and Aspergillosis is well known. Exposure of people to such fungi from different environments was studied elsewhere. However, the exposure to immunocompromised patients when they are attending a hospital for remedy is not studied so far. Hence, a study was conducted to find out the presence of species of Aspergillus in the atmosphere of he premises of 3 major hospital sin Madras, India. METHODS: Air samples from 3 major hospitals, i.e. Madras Medical College, Stanley Medical College and Kilpauk Medical College from Madras, India were collected using petridishes containing Sabouraud’s Dextrose Agar exposed through Andersen 2-stage Microbial Viable Sampler. Samples were taken for a period of 2 years with 10 days interval at each site. A total of 62 samples per site were taken at the height of 1 meter. RESULTS: Altogether 19 species of Aspergillus was isolated from all the 3 hospital premises. An average of 337 colony forming units/m3 of air per sample per site was recorded. Among the species, Aspergillus niger was dominant followed by A. flavus and A. fumigatus. The presence of toxigenic, pathogenic and allergenic species like, A. flavus, A. fumigatus, A. versicolor and A. sydowii are recorded in significant numbers. CONCLUSIONS: To control the exposure of susceptible individual to medically important strains of fungi present in hospital premises, suitable measures to be adopted. It is recommended to adopt proper sanitation methods in handling medical wastes to avoid aerosolization of such fungi in the environment. Funding: Ministry of Environment and Forests, Government of India
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Aerobiology and Morphology of Myxomycete Spores
S. O. Surratt, E. Levetin; Biological Science, The University of Tulsa, Tulsa, OK. RATIONALE: Previous studies showed significant allergenic activity for myxomycete spores; however, little is known about their atmospheric concentrations. Fruiting bodies of these fungal-like organisms are common in nature and have also been found on indoor substrates. Investigations of the airborne concentrations have been hindered by spore identification problems. The goal of this project was to investigate morphology and determine atmospheric concentrations of these spores in the Tulsa area. METHODS: Both light microscopy (LM) and scanning electron microscopy (SEM) were utilized to determine spore size, shape, and ornamentation from field collected specimens. For LM, spores were mounted in lactophenol with polyvinyl alcohol and examined at 1000x. For SEM, spores were dehydrated, air dried following hexamethyldisilazane treatment, mounted on stubs, and sputter coated. Air samples from 2001 to 2003 were collected with a Burkard Spore Trap using standard methods and examined at 1000x for spore identification and enumeration. RESULTS: LM revealed that spore pigmentation ranges from colorless to brownish-gray. Spores are typically thin-walled, globose, and 5-13m in diameter. Ornamentation varies from granular to reticulate to echinate but is not always visible with light microscopy. Myxomycete spores were identified in air samples on 64% of the days. Concentrations were highest in June, July, and September with the peak of 520 spores/m3 on 9 Sep 2003. CONCLUSIONS: Myxomycete spores are present in the air for a significant portion of the year in Tulsa, Oklahoma. More information about atmospheric concentrations from other areas is needed to determine the clinical significance of these aeroallergens. Funding: National Science Foundation (NSF)
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Quantifying Emissions of Grass Pollen and Pollen Fragments
G. Lu1, M. M. Glovsky2, J. House1, R. C. Flagan1, P. E. Taylor1; 1Chemistry and Chemical Engineering, CalTech, Pasadena, CA, 2Asthma and Allergy Center, Huntington Medical Research Institute, Pasadena, CA. RATIONALE: It is not known how whole pollen and pollen fragments are emitted into the air from highly allergenic plants. Grass pollen contains the most potent and prevalent allergens. Despite common misconceptions, physical laws dictate that the pollen grains of wind-pollinated grasses should remain on the anthers during dehiscence (opening) and until disturbed by an external force. METHODS: Experiments were performed with harvested flowers, artificial anthers made of pollen-coated substrates and other surfaces. Flowers were housed within a wind tunnel and the flowering process, as well as the effect of wind disturbances on grasses, was filmed with time-lapse video microscopy. Emissions were detected with an aerodynamic particle sizer. RESULTS: 80-95% of the pollen remained on the rye-grass and bermudagrass anthers after dehiscence in quiescent conditions. With the use of a miniature wind tunnel, a minimum threshold wind speed of 5 mph was required for pollen entrainment. Anthers rotated in a centripetal motion at 6 mph and this induced a peak in pollen and pollen fragment emission. The emission of pollen from other biological and inorganic substrates required far higher wind speeds. CONCLUSIONS: The chemical composition and nanostructure patterning of the pollen wall and anther lining likely reduce the Van der Waals forces of attraction. This results in a lowering of the wind velocity threshold needed to emit pollen grains and other particulates into the air. The rotating motion of the anther also aids in dispersal of pollen grains away from the plant at relatively low wind speed. Funding: Philip Morris Inc. USA Total Seasonal Ragweed Is Inversely Correlated With Seasonal Rainfall C. S. Barnes, F. Hu, F. Pacheco, J. Portnoy; Allergy/Asthma/Immunology, Children’s Mercy Hospital, Kansas City, MO. RATIONALE: During the August to October Ragweed season in the Midwestern United States mature ragweed plants release pollen near sunrise. Newly released pollen deposits on leaves where it dries and disperses throughout the morning hours. To test the hypothesis that unusually high amounts of rainfall during the season would diminish the total amount of airborne ragweed throughout the season we conducted the following studies. METHODS: Airborne ragweed was collected every four hours from August through October for 1997-2004. Collections were made using a Hurst-style spore trap. Slides were mounted with Calberlas stain in glycerin jelly and counted at 400x. Counts represented airborne concentration every 4 hours. Weather information was obtained from an Automated Weather Source station. We calculated the first day of ragweed season as the day when accumulated collection exceeded 1% of the total yearly collection and the last day of the season was the day 99% of the total yearly count was collected. RESULTS: The years 2000 and 2002, very hot and dry years had high total seasonal ragweed pollen counts whereas 1998, a very rainy year, had the lowest total seasonal ragweed. Total rainfall from August 1 thru October 15 for the years 1997-2003 was negatively correlated with total ragweed (-0.60) and positively correlated with the length of ragweed season (0.32). CONCLUSION: The relationship of ragweed dispersal to rainfall and is quite regular. Heavy and abundant rainfall during the ragweed season has a negative overall impact on the total ragweed pollen exposure for that year. Funding: Children’s Mercy Hospital
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Abstracts S21
J ALLERGY CLIN IMMUNOL VOLUME 115, NUMBER 2
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Aerobiology and Morphology of Myxomycete Spores
S. O. Surratt, E. Levetin; Biological Science, The University of Tulsa, Tulsa, OK. RATIONALE: Previous studies showed significant allergenic activity for myxomycete spores; however, little is known about their atmospheric concentrations. Fruiting bodies of these fungal-like organisms are common in nature and have also been found on indoor substrates. Investigations of the airborne concentrations have been hindered by spore identification problems. The goal of this project was to investigate morphology and determine atmospheric concentrations of these spores in the Tulsa area. METHODS: Both light microscopy (LM) and scanning electron microscopy (SEM) were utilized to determine spore size, shape, and ornamentation from field collected specimens. For LM, spores were mounted in lactophenol with polyvinyl alcohol and examined at 1000x. For SEM, spores were dehydrated, air dried following hexamethyldisilazane treatment, mounted on stubs, and sputter coated. Air samples from 2001 to 2003 were collected with a Burkard Spore Trap using standard methods and examined at 1000x for spore identification and enumeration. RESULTS: LM revealed that spore pigmentation ranges from colorless to brownish-gray. Spores are typically thin-walled, globose, and 5-13m in diameter. Ornamentation varies from granular to reticulate to echinate but is not always visible with light microscopy. Myxomycete spores were identified in air samples on 64% of the days. Concentrations were highest in June, July, and September with the peak of 520 spores/m3 on 9 Sep 2003. CONCLUSIONS: Myxomycete spores are present in the air for a significant portion of the year in Tulsa, Oklahoma. More information about atmospheric concentrations from other areas is needed to determine the clinical significance of these aeroallergens. Funding: National Science Foundation (NSF)
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Quantifying Emissions of Grass Pollen and Pollen Fragments
G. Lu1, M. M. Glovsky2, J. House1, R. C. Flagan1, P. E. Taylor1; 1Chemistry and Chemical Engineering, CalTech, Pasadena, CA, 2Asthma and Allergy Center, Huntington Medical Research Institute, Pasadena, CA. RATIONALE: It is not known how whole pollen and pollen fragments are emitted into the air from highly allergenic plants. Grass pollen contains the most potent and prevalent allergens. Despite common misconceptions, physical laws dictate that the pollen grains of wind-pollinated grasses should remain on the anthers during dehiscence (opening) and until disturbed by an external force. METHODS: Experiments were performed with harvested flowers, artificial anthers made of pollen-coated substrates and other surfaces. Flowers were housed within a wind tunnel and the flowering process, as well as the effect of wind disturbances on grasses, was filmed with time-lapse video microscopy. Emissions were detected with an aerodynamic particle sizer. RESULTS: 80-95% of the pollen remained on the rye-grass and bermudagrass anthers after dehiscence in quiescent conditions. With the use of a miniature wind tunnel, a minimum threshold wind speed of 5 mph was required for pollen entrainment. Anthers rotated in a centripetal motion at 6 mph and this induced a peak in pollen and pollen fragment emission. The emission of pollen from other biological and inorganic substrates required far higher wind speeds. CONCLUSIONS: The chemical composition and nanostructure patterning of the pollen wall and anther lining likely reduce the Van der Waals forces of attraction. This results in a lowering of the wind velocity threshold needed to emit pollen grains and other particulates into the air. The rotating motion of the anther also aids in dispersal of pollen grains away from the plant at relatively low wind speed. Funding: Philip Morris Inc. USA Total Seasonal Ragweed Is Inversely Correlated With Seasonal Rainfall C. S. Barnes, F. Hu, F. Pacheco, J. Portnoy; Allergy/Asthma/Immunology, Children’s Mercy Hospital, Kansas City, MO. RATIONALE: During the August to October Ragweed season in the Midwestern United States mature ragweed plants release pollen near sunrise. Newly released pollen deposits on leaves where it dries and disperses throughout the morning hours. To test the hypothesis that unusually high amounts of rainfall during the season would diminish the total amount of airborne ragweed throughout the season we conducted the following studies. METHODS: Airborne ragweed was collected every four hours from August through October for 1997-2004. Collections were made using a Hurst-style spore trap. Slides were mounted with Calberlas stain in glycerin jelly and counted at 400x. Counts represented airborne concentration every 4 hours. Weather information was obtained from an Automated Weather Source station. We calculated the first day of ragweed season as the day when accumulated collection exceeded 1% of the total yearly collection and the last day of the season was the day 99% of the total yearly count was collected. RESULTS: The years 2000 and 2002, very hot and dry years had high total seasonal ragweed pollen counts whereas 1998, a very rainy year, had the lowest total seasonal ragweed. Total rainfall from August 1 thru October 15 for the years 1997-2003 was negatively correlated with total ragweed (-0.60) and positively correlated with the length of ragweed season (0.32). CONCLUSION: The relationship of ragweed dispersal to rainfall and is quite regular. Heavy and abundant rainfall during the ragweed season has a negative overall impact on the total ragweed pollen exposure for that year. Funding: Children’s Mercy Hospital
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Abstracts S21
J ALLERGY CLIN IMMUNOL VOLUME 115, NUMBER 2