Phenotypic and Genotypic Identification and Antifungal Susceptibility of Some Fungi Isolated from Tympanotonus fuscatus var. radula

Aim: This study aimed to identify fungi isolated from Tympanotonus fuscatus var. radula and evaluate its level of susceptibility to known antifungal compounds.

Place and Duration of Study: Biotechnology Advanced Research Centre, Sheda Science and Technology Complex, Abuja between September and December 2019.

Methods: Tympanotonus fuscatus var. radula samples were purchased from the Keffi, Masaka, and Orange markets in Nasarawa State, Nigeria. Fungal isolation was achieved using Sabouraud dextrose agar supplemented with chloramphenicol and incubated at 28ᵒC for 5 days. ITS-1 and ITS-4 primers were used at 94°C for 2 min, 52°C for 1 min, and 72°C for 2 min for the polymerase chain reaction before sequencing at Inqaba Biotech South Africa. Disk diffusion technique was employed for antifungal susceptibility testing.

Results: Data obtained revealed that the suspected fungal species exhibited a generally higher level of resistance (19-40 mm) to 1 µg voriconazole in addition to a 20-35.5 mm zone of inhibition against 10 µg ketoconazole. Blast sequence analysis of the isolated samples revealed a 99.65% sequence homology to Meyerozyma guilliermondii, 99.38% to Fusarium oxysporium isolate E-225 1 and 96.23% to Aspergillus terreus isolate A2S4.

Conclusion: Food safety involves isolating and accurately identifying disease causing pathogens such as fungi in food. Based on the fungal load obtained from this study, proper cooking and handling of sea-food which would otherwise cause disease, is highly recommended.