SPORES OF Aspergillus versicolor ISOLATED FROM INDOOR AIR OF A MOISTURE-DAMAGED BUILDING PROVOKE ACUTE INFLAMMATION IN MOUSE LUNGS

Abstract

Microbial growth in moisture-damaged buildings has been associated with respiratory health effects, and the spores of the mycotoxin producing fungus Aspergillus versicolor are frequently present in the indoor air. To characterize the potential of these spores to cause harmful respiratory effects, mice were exposed via intratracheal instillation to a single dose of the spores of A. versicolor (1 x 10(5), 1 x 10(6), 5 x 10(6), 1 x 10(7), or 1 x 10(8) spores), isolated from the indoor air of a moisture-damaged building. Inflammation and toxicity in lungs were evaluated 24 h later by assessment of biochemical markers and histopathology. The time course of the effects was investigated with the dose of 5 x 10(6) spores for up to 28 days. The exposure to the spores increased transiently proinflammatory cytokine levels (tumor necrosis factor [TNF] alpha and interleukin [IL]-6) in bronchoalveolar lavage fluid (BALF). The cytokine responses were dose and time dependent. The highest cytokine concentrations were measured at 6 h after the dose, and they returned to the control level by 3 days. Moreover, the spores of A. versicolor recruited inflammatory cells into airways: Neutrophils peaked transiently at 24 h, macrophages at 3 days, and lymphocytes at 7 days after the dosing. The inflammatory cell response did not completely disappear during the subsequent 28 days, though no histopathological changes were seen at that time point. The spores did not induce expression of inducible nitric oxide synthase in lavaged cells. Only the highest spore dose (1 x 10(8)) markedly increased serum IL-6, increased vascular leakage, and caused cytotoxicity (i.e., increased levels of albumin, total protein, lactate dehydrogenase [LDH], and hemoglobin in BALF) in the airways. In summary, the spores of A. versicolor caused acute inflammation in mouse lungs. This indicates that they have potential to provoke adverse health effects in the occupants of moisture-damaged buildings.

A year-round investigation of indoor airborne fungi in Croatia

“…Aspergilli are primary colonizers and can be customized to a w values below 0.8, which allows them to succeed in damp indoor environments more likely than other moulds (22,39). Aspergillus versicolor is the most frequently reported fungal species in section Versicolores from damp indoor environments and its presence might be related to Sick Building Syndrome (17)(18)(19)(20). Recent publications based on the molecular identification of Aspergillus species (Versicolores) indicated that Aspergillus versicolor sensu stricto were not common in buildings.…”

“…Aspergillus flavus and A. parasiticus from the Flavi section are important producers of the highly toxic and carcinogenic aflatoxin B1 and these species grow on almost all crops (16). Aspergillus versicolor is the most frequently reported Versicolores fungus from damp indoor environments and its presence might be related to Sick Building Syndrome (17)(18)(19)(20). Moreover, it represents a special threat for human health due to its very small spores and release of mycellium fragments (10) as well as ability to produce sterigmatocystin (21,22).…”

Analysis of Fungal Spore Mycotoxin and the Relationship Between Spore Surface Area and Mycotoxin Content Utilizing a Protein Translation Inhibition Assay

“…versicolor is commonly found in unhealthy indoor environments and studies have shown that inhalation exposure to Asp. versicolor spores may cause acute inflammation and cytotoxic effects [27,28]. To this end we analyzed seven different Asp.…”

High Indoor Microbial Levels Are Associated with Reduced Th1 Cytokine Secretion Capacity in Infancy

“…Despite the lack of firm evidence concerning the effects of fungal exposures on immune responses emerging from this study, living in a moisture-damaged building and the presence of mold seem to increase the risk of respiratory symptoms, but rarely allergic sensitization, in childhood [9,39]. In addition, previous in vitro [40] and in vivo [41] studies imply that fungal components derived from moldy buildings have a real capacity to evoke severe health problems. However, further studies are needed to investigate the extent to which fungal exposures affect immune development and the health of newborns.…”