Isolation of <i>Simplicillium sympodiophorum</i> and <i>Toxicocladosporium irritans</i> from the Blowout Air of Household Air Conditioners

Abstract

Household air conditioners are known to be contaminated with dematiaceous fungi such as genus Toxicocladosporium and genus Cladosporium. We frequently encounter cases in which a large amount of fungi, which are presumed to belong to the family Cordycipitaceae, are isolated from the blowout air of the household air conditioners. Therefore, the Cordycipitaceae isolated in the survey of four cases of the air conditioners were identified by genetic analyses. As a result, all of them were found to be Simplicillium sympodiophorum. The concentration of airborne fungi, S. sympodiophorum in the blowout air was high (> 10 4 cfu/m 3 ) as exceeding the upper limit of quantification in three of four cases, and 5,000 cfu/m 3 in one case. This study revealed that S. sympodiophorum contaminated multiple air conditioners. Genus Toxicocladosporium was also isolated from the two air conditioners, and it was found to be Toxicocladosporium irritans by the genetic analysis.

A Snapshot Picture of the Fungal Composition of Bee Bread in Four Locations in Bulgaria, Differing in Anthropogenic Influence

“…Until now, Toxicocladosporium genus has never been reported to be associated with bee products and bees. Members of the genus were found in many different environments such as soils [56], marine waters [57], household air conditioners [58], bronchoalveolar lavage fluid [59], different plants [60,61], and even in insects-in the planthopper gut [62] and the Thitarodes larvae hemolymph [63]. However, members of this genus have never been established as strict pathogens of the plant and animal species where they thrive.…”

Moldy odor from air conditioners in the residences of Japanese participants with and without asthma

“…8,14 The number of airborne fungi increases by 10-10 000 fold immediately after starting a contaminated air conditioner. 6 Moldy odors originating from air conditioners were present in more than one-third of the residences of participants with and without asthma. Not only air conditioner-related factors, such as length and duration of its use, but also household condensation reflecting high indoor relative humidity were associated with the moldy odor.…”

“…If not properly managed, air conditioners are a major site of indoor mold growth, possibly causing or worsening ABPM and hypersensitivity pneumonia 8,14 . The number of airborne fungi increases by 10–10 000 fold immediately after starting a contaminated air conditioner 6 . Moldy odors originating from air conditioners were present in more than one‐third of the residences of participants with and without asthma.…”

“…Therefore, heating, ventilating, and air‐conditioning (HVAC) systems are beneficial for reducing the burden of airborne fungi 5 . However, if not properly maintained, air conditioners themselves can be contaminated with fungi and, consequently, spread fungal spores into indoor air 6,7 . We previously reported a case of ABPM with repeated deterioration due to recurrent exposure to a contaminated air conditioner.…”

“…5 However, if not properly maintained, air conditioners themselves can be contaminated with fungi and, consequently, spread fungal spores into indoor air. 6,7 We previously reported a case of ABPM with repeated deterioration due to recurrent exposure to…”