The high diversity of Scedosporium and Lomentospora species and their prevalence in human-disturbed areas in Taiwan

Abstract

Scedosporium and Lomentospora are important opportunistic pathogens causing localized or disseminated infection in humans. Understanding their environmental distribution is critical for public hygiene and clinical management. We carried out the first environmental survey in urbanized and natural regions in Taiwan. Overall, Scedosporium and Lomentospora species were recovered in 132 out of 273 soil samples (48.4%) across Taiwan. We morphologically and molecularly identified six Scedosporium and one Lomentospora species. All four major clinical relevant species were isolated with high frequency, i.e., Scedosporium apiospermum (42.4%), S. boydii (21.8%), Lomentosporaprolificans (14.5%), S. aurantiacum (8.5%); two clinically minor species, Pseudallescheria angusta (6.7%) and S. dehoogii (5.6%), and a saprobic species, S. haikouense (0.6%), had moderate to rare incidence. These fungal species had high incidence in urban (48.6%) and hospital (67.4%) soil samples, and had limited distribution in samples from natural regions (5%). Multivariate analysis of the fungal composition revealed strong evidence of the preferential distribution of these fungi in urban and hospital regions compared with natural sites. In addition, strong evidence suggested that the distribution and abundance of these fungal species were highly heterogeneous in the environment; samples in vicinity often yielded varied fungal communities. We concluded that these fungal species were prevalent in soil in Taiwan and their occurrences were associated with human activities. Although, hygiene sensitive sites such as hospitals were not harboring heavier fungal burdens than other urban facilities in our survey, still, aware should be taken for the high frequency of these clinical relevant species around hospital regions.

Keywords: Pseudallescheria; emerging pathogen; fungal diversity; soil fungi.