Unravelling soil fungal communities in dumpsites in Kabale, Western Uganda using culturomics

Inadequate waste disposal systems have long been a perennial problem, with no clearly safe solution in sight in most developing countries. Dumpsites harbor microbial pathogens in the soil ecosystem that can cause disease outbreaks upon their seepage into the water bodies. However, there is a paucity of investigation on the diversity of fungi in dumpsites in Uganda. Hence, this research aims at evaluating the diversity and distribution patterns of fungi associated with top soils from fifteen different dumpsites in Kabale, South west, Uganda. Culturomics approach was employed in this investigation. Isolation of the fungal species was done using five different culture media, i.e., Potato Dextrose Agar (PDA), Malt Extract Agar (MEA), ChromAgar (CA), FastFung (FF), and Saboraud Dextrose Agar (SDA). Fungal isolation was carried out using the soil dilution plate technique. ITS rRNA gene sequencing was used to identify purified isolates. FF emerged as the most effective agar, yielding the highest number of fungal isolates, followed by PDA, MEA, CA, and SDA. In all, 54 different isolates were obtained. Trichoderma, Fusarium, and Aspergillus sp were the most prevalent. Also, pathogenic and opportunistic fungi such as Simplicillium lamellicola, Mortierella multispora, and Torulaspora delbrueckii were isolated. All Aspergillus isolates were further screened for azole-resistance (itraconazole, voriconazole, posaconazole, and Amphotericin B). Results showed most Aspergillus species have lower MIC; however, A. clavatus had an MIC of 1.5 ug/mL. This work further emphasizes the need for regular monitoring of dumpsites for fungi, which can be of public health concern.