Mycobiome of Bondi Beach Sand

• Main Author: Terre, Darcii D
• Format: Web Resource
• Language: English
• Published: Morressier 01.01.2017
• DOI: 10.26226/morressier.5ac39996d462b8028d89a095

Title: Mycobiome of Bondi Beach SandObjectives:The Australia coastline consists of numerous beaches, regularly used for recreational activities by locals and tourist alike. The presence of pathogenic fungi in sand could have public health implications but it has not been assessed in Australia so far. Various clinically significant fungi have been found residing in beach sand worldwide, such as, Trichophyton, Microsporum, Cladosporium, Epidermophyton and Candida. Many factors influencing the fungal load in beach sand with the frequency and level of human interaction being a significant contributor. Other features such as the physical environment, biological factors and nutrient availability impact their capacity to transiently persist or thrive in that environment. This study involves six locations at Bondi beach (Sydney), identifying medically relevant fungal species and assessing the beach as a potential reservoir for fungal infection. Focusing on correlations between the abundance of fungal species, characteristics of the beach and other conditions such as seasonality and level of human activity. Different methods were used and compared to characterize the mycobiome of beach sands in Bondi beach. Methods: Beach sand was collected from six areas of Bondi beach, with five samples taken at each of the locations and made into a composite. From each composite 1g of sand was placed directly onto three types of media u2013 Sabouraud, Sabouraud Dextrose and Mycosel agar and incubated at 27oC. For traditional sequence based identification, individual colonies were selected from the agar plates and subcultured on a fresh agar plate. After 24h, cultures were visually checked for purity and if contaminated, subcultured again. Phenol-chloroform extraction method was used to extract DNA. ITS1u2013ITS4 primer set was used to amplify the primary fungal barcode (ITS) and Al33Fu2013Al33R or Al34F-Al34R set for the secondary one (TEF1u03b1). All PCR products were sequenced in both the forward and reverse directions by Sanger sequencing.For metabarcoding analyses, total genomic DNA was extracted from sand samples using the PowerMax Soil DNA Isolation kit (MoBio) following manufactureru2019s instructions. Fragments were amplified with universal fungal primers, ITS1F and ITS2 targeting the ITS1 region. The resulted PCR amplicon were sequenced on MiSequ00ae platform from Illumina. Reads were processed using the UNOISE algorithm to obtain error-corrected (denoised) sequences. Each denoised sequence was considered to be an Operational Taxonomic Unit (OTU). Taxonomy was predicted for the OTU sequences using the SINTAX algorithm in usearch v10.0.Results: Many fungal species have been identified by traditional culturing methods and the ITS barcode with Sanger Sequencing. Many environmental species were recovered but some are medically relevant such as Mucor, Rhodotorula, Cladosporium, Penicillium and Alternaria have been recovered. In the first two months of sampling over 150 isolates were recovered from six locations on Bondi beach, with 30 identified at time of writing. Further results, including the metabarcoding analysis of the samples will be available by the conference. Conclusion:This is the first study of the mycobiome of beach sand in Australia. Some of the identified species are of medical relevance and a potential source of human infection. Further research is needed to better understand the implications to public health.