Molecular characterization of mycotoxin-producing Aspergillus parasiticus and sensitivity pattern to different disinfectants

Abstract

Aims:The study was aimed to isolate and characterize the mycotoxin-producing filamentous Aspergillus parasiticus from the feed samples. The sensitivity pattern of the isolates was assessed against different disinfectants. Methodology and results: Fifty different feed samples were screened for A. parasiticus isolation. Isolates were subjected to macroscopic and microscopic characterization. Polymerase chain reaction was performed to confirm the isolates at the genomic level. Mycotoxin producing potential of the isolates was assessed by thin-layer chromatography (TLC). To quantify the toxins, high performance liquid (HPLC) was employed. The antifungal potential of disinfectants was determined by the well diffusion method followed by minimum inhibitory concentration (MIC) calculation. Out of twenty isolates of A. parasiticus, 11(55%) isolates were observed positive for toxin production. Three toxigenic isolates (AspP2, AspP4 and AspP8) were selected to evaluate their susceptibility against disinfectants by well diffusion method. AspP2 produced maximum (5.90 ng/mL) toxin, followed by AspP4 (3.11 ng/mL) and AspP8 (18.47 ng/mL). Terralin showed maximum fungicidal activity with 29.66 ± 8.08 mm zone of inhibition at 0.42 µg/mL MIC. Hypochlorite and Instru Star showed 99% disinfection with 30, 60 and 90 min contact time (6 mean log reduction) for all A. parasiticus isolates. Alpha Guard inhibited growth after 15 min contact time for all the isolates. Conclusion, significance and impact of study:This study provides data indicating the contamination of feed samples with mycotoxin-producing A. parasiticus isolates and their sensitivity against commercially available disinfectants. Use of these disinfectants in appropriate concentrations and time could help prevent the contamination of food, feed and healthcare settings with the fungal species.