## 4 Discussion
For instance, we found that the Shannon indices observed in this study, ranging from 0.02 to 1.67, were similarly low to those observed in South Korea, ranging from 0.14 to 2.29 [18]. This suggests that each moldy spot includes a small number of fungal species, regardless of geographical differences. In addition to our previous study conducted in South Korea [18], several similar high-throughput DNA-sequencing-based studies have analyzed fungal communities on indoor surfaces using swab sampling followed by high-throughput sequencing [36; 37; 38]. [PERSON] et al. [36] analyzed fungal communities on public restroom floors in California in the U.S. and reported that _Cladosporium_, _Saccharomyces_, and _Alternaria_ were the three most abundant genera. [PERSON] et al. [37] analyzed fungal communities in visible molds in a damp building in Connecticut in the U.S. and found _Sterigmatomyes_, _Stachybotrys_, and _Aspergillus_ to be the dominant genera. [PERSON] et al. [38] analyzed fungal communities on doorframes in rooms of hotels in 19 countries in Europe and Asia, and reported that the abundances of _Aspergillus_ were higher in the countries with low altitudes, including Thailand. The tendency was opposite to the findings of our studies, but the difference was small, i.e., 0.053% in Thailand vs. 0.094% in South Korea. Exposure to indoor fungi can cause respiratory illnesses such as infection and allergies [39; 40; 41; 42]. For instance, indoor mold exposure and dampness are known to reduce lung function among nonasthmatic adults and are related to asthma development and aggravation in children, whereas asthma in adults can be aggravated by indoor dampness and mold exposure [43; 44]. Toxicine fungi, such as _Stachybotrys chartarum_, in water-damaged buildings are associated with respiratory illnesses [45; 46]. Thus, one of the aims of this study was to investigate potential fungal pathogens and allergens that might cause such respiratory illnesses in residents of flood-damaged homes. To date, about 80 fungal genera have been identified to cause type I allergies [47], and we found several genera that contain such allergenic species, e.g., _Trichoderma_ (4.0%) and _Alternaria_ (3.8%) (Figure 5). _Tricoderma_ also contains human pathogens such as _Tricoderma harzianum_, _Tricoderma lixii_, and _Tricoderma longbrachiatum_[48; 49]. We identified several genera that contain opportunistic infectious pathogens, e.g., _Aspergillus_ (0.053%), _Candida_ (0.53%), _Fusarium_ (0.13%), and _Penicillium_ (0.77%). Melanized fungi, which are thought to cause infection in humans [50; 51], were also detected, with examples including _Cladosporium_ (0.055%), and _Cyphellophora_ (1.2%). Genera associated with toxigenic species [52; 53] were also detected. These genera included _Stachybotrys_ (0.74%), _Fusarium_ (0.13%), and _Trichoderma_ (4.0%). Yeasts and yeast-like fungi were also detected in the flood-damaged homes in Thailand. Examples include _Rhodotorula_, which is a saprophytic yeast that can be isolated from both environment and clinical specimens. _Rhodotorula_ contains opportunistic human pathogenic species such as _Rhodotorula mucilaginous_[54; 55]. Another yeast genus detected was _Candida_, which includes pathogenic species that can cause candidiasis and candidemia [56; 57]. _Cyphellophora_, which is a black yeast-like fungal genus, was detected with a mean relative abundance of 1.2% (Figure 5). This melanized genus includes human pathogenic species such as _Cyphellophora europaea_, and is isolated from black biofilms in wet indoor environments such as kitchens and bathrooms [58; 59; 60].