Abstract

Aim: This study investigated the occurrence and antifungal resistance of fungi isolated from fishpond water, surrounding soil, and air in aquaculture environments.
Methods: Between September and November 2024, samples were collected from four locations (Woji Estate 1, Woji Estate 2, Elelenwo, and Rivers State University). Fungal load and species were determined using standard microbiological procedures, and antifungal susceptibility was tested by the Kirby–Bauer disk diffusion method.
Findings: Fungal counts ranged from 7.3×10³–22×10³ CFU/g in soil, 1.3×10³–5.0×10³ CFU/mL in water, and 4.2×10³–8.5×10³ CFU/m³ in air. Dominant fungi included Aspergillus niger, Penicillium spp., Rhizopus stolonifer, Galactomyces candidus, Aspergillus terreus, Mucor spp., Aspergillus nidulans, Rhodotorula spp., Candida spp., and Fusarium spp. Susceptibility varied: Rhodotorula spp. (32 mm, ketoconazole) and G. candidus (30 mm, fluconazole) were most sensitive, while A. nidulans and Fusarium spp. were resistant to all agents. Physicochemical conditions supported fungal growth, with water pH 6.6–8.6, conductivity 100.3–260.8 µS/cm, DO 10.9–31.8 mg/L, BOD up to 58.2 mg/L, and soil showing pH 6.9–7.8, nitrogen 1.7–2.6%, and phosphorus up to 1.6 mg/g.
Conclusion: The findings reveal diverse fungal populations and widespread antifungal resistance in aquaculture environments, raising concerns for fish health, ecosystem balance, and public health. Routine monitoring and sustainable antifungal strategies are recommended.

Key words: Fungal contamination, Antifungal susceptibility, Azole resistance