Molecular identification of filamentous fungi diversity in North Coast beaches sands of Puerto Rico

Abstract

The Northern region has a great variety of beaches with diverse microbial characteristics. Beach sands receive direct contamination from the garbage generated by people, which serves as nutrient for fungi growth. The objectives of this investigation were to assess the filamentous fungi diversity of four popular beaches; identify the genus and species; and identify the taxonomic relationship between the most abundant fungi. The beaches studied are located in the towns of Vega Baja, Manatí, Barceloneta and Arecibo. One sample of dry sand per month from three equidistant points was acquired every month for a year in each beach. The samples were homogenized according to dry (December-April) and humid (May-November) seasons, for a total of four composite samples per season. The DNA of each sample was isolated and quantified; and, upon sequencing, evaluated by metagenomics analysis with MG-RAST. There were 104 fungi species identified by DNA sequencing analysis. The most abundant were: Aspergillus penicillioides, Aspergillus terreus, Microascus sp., Arthrographis kalrae, Paramicrosporidium sp., Dokmaia sp., Gliomastix polychroma and Aspergillus sp. The taxonomic analysis demonstrated that there is no relationship in the genus of the most abundant species. As significant finding, 66 species of new registries were identified, including Malassezia restricta, Arthrographics eremomycyces, and Cephaliophora tropica. Not only were many of the species pathogenic, several genera of filamentous fungi have been previously isolated from patients in nasal culture, and can cause eye, respiratory and skin disease. The majority of these fungi use direct contact and air transport as transmission vehicle to the host.