Aerobiology Of Aerobiology Of PenicilliumPenicillium and and AspergillusAspergillus Type Spores Type Spores

ByBy

**Abeer Khattab and Estelle LevetinAbeer Khattab and Estelle Levetin

INTRODUCTIONINTRODUCTION

The atmosphere in Tulsa, Oklahoma contains high concentrations and many types of aeroallergens – both fungal spores and pollen.

The genera Penicillium and Aspergillus are naturally considered as soil-borne saprophytes, but they have been reported in many studies as important aeroallergens.

There are few studies on the aerobiology of There are few studies on the aerobiology of Pen/AspPen/Asp spores.spores.

OBJECTIVESOBJECTIVES

The main objective of this study is to The main objective of this study is to understand the aerobiology of understand the aerobiology of Pencillium Pencillium and and AspergillusAspergillus spores, and the effect of spores, and the effect of meteorological conditions on the meteorological conditions on the concentration of this type of spore.concentration of this type of spore.

Aspergillus niger PenicilliumAspergillus niger Penicillium

PenicilliumPenicillium and and AspergillusAspergillus Spores Spores

PenicilliumPenicillium and and AspergillusAspergillus spores are spores are small (2-6 small (2-6 μμm) so they m) so they remain airborne for remain airborne for extended timeextended time

On spore trap slides On spore trap slides spores look alike spores look alike

So, they are commonly So, they are commonly grouped as Pen/Asp grouped as Pen/Asp spores.spores.

METHODSMETHODS Air samples were collected with a Burkard Air samples were collected with a Burkard spore trap (standard orifice) that was spore trap (standard orifice) that was located on the roof of a building at the located on the roof of a building at the University of Tulsa (12m height). University of Tulsa (12m height).

Burkard daily slides were analyzed for some Burkard daily slides were analyzed for some of the most common and important airborne of the most common and important airborne fungal spores for one year (2005) by light fungal spores for one year (2005) by light microscopy using the single traverse microscopy using the single traverse method at 1000x. method at 1000x.

Cladosporium, Alternaria, Cladosporium, Alternaria, Pen/AspPen/Asp, Curvularia, , Curvularia, Drechslera, Drechslera, AscosporesAscospores, , Basidiospores Basidiospores, , Nigrospora, MyxomycetesNigrospora, Myxomycetes, Smuts and other , Smuts and other spores were the most common counted spores spores were the most common counted spores types.types.

The concentration of each spore type as well as The concentration of each spore type as well as the total concentration of all the fungal spores the total concentration of all the fungal spores were calculated. were calculated.

Spore data were statistically analyzed to see the Spore data were statistically analyzed to see the relationship with the environmental factors such relationship with the environmental factors such as wind speed, rain, humidity, and temperature. as wind speed, rain, humidity, and temperature.

Effect of sampler orifice onEffect of sampler orifice on Penicillium/Aspergillus Penicillium/Aspergillus spore spore

concentrationsconcentrations

One difference between samplers is their One difference between samplers is their efficiency in sampling small spores.efficiency in sampling small spores.

Sampler efficiency is partially based on the size of Sampler efficiency is partially based on the size of its orifice (cut size).its orifice (cut size).

The standard orifice captures spores of 3.7 The standard orifice captures spores of 3.7 µµm m and above while the alternate orifice collects and above while the alternate orifice collects spores of 2.17 spores of 2.17 µµm and above.m and above.

Below these levels sampler efficiency drops off.Below these levels sampler efficiency drops off.

Alternate orificeAlternate orifice

From 1 Jul – 31 Oct 2005 a second Burkard with an From 1 Jul – 31 Oct 2005 a second Burkard with an alternate orifice was used to see if more spores alternate orifice was used to see if more spores would be registered would be registered

The second Burkard was also placed on the roof The second Burkard was also placed on the roof of the same building.of the same building.

The same method of analysis was used. The same method of analysis was used.

Statistical analysis (t test) was used to compare Statistical analysis (t test) was used to compare the total spore concentrations and Pen/Asp spore the total spore concentrations and Pen/Asp spore concentrations from both samplers. concentrations from both samplers.

Alternate Orifice

Standard Orifice

Outdoor Air Sample from Burkard Spore TrapOutdoor Air Sample from Burkard Spore Trap

RESULTSRESULTS

Pen/AspPen/Asp spores were registered on 362 spores were registered on 362 days in 2005 with peak concentration on 1 days in 2005 with peak concentration on 1 Oct with 1853 spores/mOct with 1853 spores/m33. .

August had the highest monthly mean August had the highest monthly mean concentration of 525 spores/mconcentration of 525 spores/m3. 3.

April had the lowest mean concentration at April had the lowest mean concentration at 131 spores/m131 spores/m33..

Pen/AspPen/Asp spores represented 5.7% of the spores represented 5.7% of the yearly total spore load (standard orifice). yearly total spore load (standard orifice).

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Effect of meteorological conditionsEffect of meteorological conditionsThere was a positive significant correlation There was a positive significant correlation between the concentration of between the concentration of Pen/Asp Pen/Asp spores spores and mean daily temperature (r = 0.666, p<0.01)and mean daily temperature (r = 0.666, p<0.01)

There was a negative significant correlation There was a negative significant correlation between the concentration of between the concentration of Pen/Asp Pen/Asp spores spores and precipitation (r = - 0.122, p= 0.019)and precipitation (r = - 0.122, p= 0.019)

There were no significant correlations between There were no significant correlations between Pen/AspPen/Asp spore concentration and wind speed spore concentration and wind speed (r= 0.042, p = 0.422), or relative humidity (r= 0.042, p = 0.422), or relative humidity (r = 0.0456, p = 0.385) throughout the year. (r = 0.0456, p = 0.385) throughout the year.

Penicillium/Aspergillus Spore Concentrations in Two Different Orifices

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Effect of the Burkard Orifice Size on Effect of the Burkard Orifice Size on Penicillium/Aspergillus Penicillium/Aspergillus Spore Spore

ConcentrationsConcentrations

July 1July 1stst - Oct 31, 2005 data - Oct 31, 2005 data

Standard orifice meanStandard orifice mean Pen/Asp spore concentration Pen/Asp spore concentration was 477 spores/mwas 477 spores/m33 while that of the alternate while that of the alternate orifice was 744 spores/morifice was 744 spores/m33

Mean from alternate orifice was significantly higher Mean from alternate orifice was significantly higher than that of the standard orifice (t = -8.8, p<0.01) than that of the standard orifice (t = -8.8, p<0.01)

There were no significant differences between total There were no significant differences between total airborne fungal spore concentrations with the two airborne fungal spore concentrations with the two orifices (t = -0.93, p>.01)orifices (t = -0.93, p>.01)

CONCLUSIONSCONCLUSIONS

Pen/Asp spores were present in the atmosphere Pen/Asp spores were present in the atmosphere throughout the year with the highest throughout the year with the highest concentration in late summer.concentration in late summer.

Pen/Asp spore concentration was affected by the Pen/Asp spore concentration was affected by the daily average temperature and precipitation. daily average temperature and precipitation.

The orifice size of the Burkard sampler The orifice size of the Burkard sampler influenced the spore capture with higher influenced the spore capture with higher concentrations registered by the alternate orifice.concentrations registered by the alternate orifice.

Using the standard orifice, aerobiologists may be Using the standard orifice, aerobiologists may be underestimating the importance of airborne underestimating the importance of airborne Pen/Asp spores.Pen/Asp spores.