Objective: To evaluate fungal contamination on the surface of Chinese herbal medicines and explore an appropriate method for fast and efficient identification of contaminant fungi.
Method: Chinese herbal medicines were first washed and the washing solution was plated onto potato dextrose agar (PDA) to obtain the pure isolates. For molecular identification, two new pairs of specific primers were designed according to ITS region of fungi genome sequences. The strains were identified through polymerase chain reaction (PCR) and sequence analysis.
Result: Fifty fungal strains were obtained from the surface of 15 Chinese herbal medicines with the percent of contaminated samples of 93.3%. Twenty-seven strains among them were successfully identified.
Conclusion: Fungal contamination on the surface of Chinese herbal medicines is quite common. Although different fungal species were isolated, the genus Aspergillus was the predominant. The primer pairs developed in this study are compatible and can be used to identify fungal species from the surface of Chinese herbal medicines.