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Category: Aerobiology

Cladosporium species in indoor environments

Cladosporium is a fungus that mostly found in indoor and outdoor molds. It is a species that formed in simple or branching chains and produced olive-green to brown colonies with pigmented conidia. Many of these Cladosporium species commonly found on living and dead plant materials. In which spores are dispersed by the wind that is why it is extremely abundant in outdoor air. On the other hand indoor species may grow when moisture of the surface is present. These species also belongs to a monophyletic group that is well bounded by having a unique coronate structures. In this current research a multilocus DNA sequence typing approach been conducted. As well as morphological examinations and cultural characteristics used as basis for identification and delimitation.


Diversity of Cladosporium in indoor environments

Cladosporium phylogeny and taxonomic structures have been reviewed extensively however, no enough study conducted about its presence in indoor environments. A molecular phylogenetic approach has been made to identify common indoor species. Since fungi usually present in indoor environment that produced toxins or holds allergens which cause hazards on health. That is why it is very important to know what are fungal species thrives indoors.


There were 46 species found indoors wherein four are found to be human-derived samples. Sixteen species identify as new in which 6 belong to Cladosporium complex and the most common are Cladosporium halotolerans. These indoor species grow better compared to other indoor fungi such as Aspergillus and Penicillium. As part of worldwide survey of the indoor mycobiota about 520 new Cladosporium isolates collected mainly from China, Europe, North America, South Africa and New Zealand.


Moreover, Cladosporium exhibits very condensed growth pattern forming round pigmented cells in the central colony and quick spore formation. It can also grow at lower available nutrients and the ability to deal with humidity changes in indoor situations. Interestingly the availability of water for these fungi is highly dynamic and influenced by changing temperature. The pure morphological identification of Cladosporium is clearly possible with the aid of molecular data and Cladosporium halotolerans is the most frequently isolated Cladosporium species indoors.


Source: Prepared by Joan Tura from  Studies in Mycology

Volume 89, March 2018, Pages 177-301



Canadian system for outdoor air monitoring

Aerobiology Research was first formed in 1994 to collect outdoor air samples and report on pollen and fungal spore levels. We started with 12 sites across Canada and now have 30 where samples are gathered and our laboratory analysis is done. The database we have collected is also stored in our laboratory in Ottawa for all sites. This data is used to provide information to the public through media and pharmaceutical companies for all of our sites. To check on what sites we have I am including our web site URL- (more…)

Fall and Winter Allergies

Well, the outdoor allergy season is almost over and we will soon be finished doing collections and providing information to the public through our reports that we produce.

The pollen in the air is generally at low levels or even absent on many days now. But people may still be suffering for a while in some areas where the temperatures will be remaining high enough for the fungal spores to continue growing and releasing the spores in the air. (more…)

What’s next for the allergy season?

This cold spring brought a late season for the trees but this does not have any impact on what is going to happen in August and the fall for outdoor pollen and mold spores. There are many weeds that cause seasonal allergies. Some of them include plantain, nettles, ragweed and others. But only weeds that are mostly or partially air pollinated are included in outdoor air samples. The weeds do not include ones that have a strong smell, colourful flowers or do not get airborne (Dandelion). These other weeds can cause allergic reactions but only on contact with the skin. (more…)

The pollen season for 2014 – a Pollen Vortex?

I am going to do a follow up of my last post regarding the pollen season of 2014 and the cold spring that occurred. First I would like to refer to this term that has been used this season called the pollen vortex. A vortex refers to weather, like the wind, and not to pollen. Our research has proven that pollen release is affected by temperature, sunshine, rain etc but the wind is just a vector by which the tree pollen are carried in the atmosphere. (more…)

5 Unexpected Activities that Release Endorphin

Endorphin is one of the natural “happy” chemicals released by our bodies. This chemical which is secreted by our brains is responsible for helping us relieves stress, anxiety, and allows us to have higher tolerance for pain. Sometimes called as the natural morphine, endorphin affects our pain and pleasure perception.


Where is spring and the pollen allergy season?

We hear it all the time. When will winter be over? Well not only are people saying it but so are the trees.

This winter the March weather has been very cold with lots of snow. April has begun with very cold temperatures as well and the temperatures are warming up very slowly. The sampler at our site in Ottawa on April 6th is still surrounded by snow. The winter snow cover is good for the trees since it provides protection for them during the cold winter months. What they don’t like is a stretch of warm weather in the spring followed by a cold snap for several days or even weeks. This can fool the trees into budding and it can have a profound effect on the pollen season to the point of almost eliminating it if the trees have started budding. We don’t have that problem this year so far. (more…)

Aeroallergen Monitoring in Canada

As I mentioned in my last blog, the study of aeroallergens depends highly on having data.  In order to have data, we need to obtain samples of outdoor air, and analyze them to identify and quantify each type of pollen and fungal spore particle collected.  We need to do this on a continuous basis, at set intervals, at multiple locations, for many years, to obtain a data set large enough to be able to study aeroallergen seasonal behaviour. (more…)

An Introduction to Aeroallergens

Pollen is a microscopic grain discharged from the male part of a flower or from a male cone that can fertilize the female ovule.

Plants have evolved to have their pollen be transported either by the wind, or by insects or other animals. Insect and animal pollinated plants are not considered to be aeroallergens, not because people aren’t allergic to them, but because the pollen from those plants are not designed to be distributed in the air (more…)