title: An investigation of fungal contamination on the surface of medicinal herbs in China.
abstract: BACKGROUND
  The dried parts of medicinal herbs are susceptible to the infection of fungi during pre- or post-harvest procedure. This study aimed to investigate the presence of fungi and their metabolites mycotoxins on the surface of medicinal herbs collected from China.
  
  
  METHODS
  Forty-five retail samples of 15 different medicinal herbs were collected from 3 different regions in China. Then the potential fungi were immediately washed off from the surface of each sample with 0.1% Tween-20 followed by incubation of the rinse on petri-dish with potato dextrose agar containing chloramphenicol at 28 °C. The obtained fungi were isolated as single colonies and then characterized by morphology and molecular identification using internal transcribed spacer (ITS) sequencing with extracted DNA. Meanwhile, the mycotoxin-producing potential of the isolates was studied by liquid chromatography-tandem mass spectrometry (LC-MS/MS).
  
  
  RESULTS
  A total of 126 fungi were identified from the surface of samples by morphology and ITS sequencing, withAspergillusandPenicilliumgenera as the predominant contaminants. The mycotoxin-producing potential analysis showed that 6 of 8A. versicolorisolates could produce sterigmatocystin. All 3A. aculeatusisolates produced ochratoxin A, but only 1 of 3A. flavusstrains produced aflatoxins B1and B2without G1and G2. Although the sample contamination ratios were high (≥95.6%), there was no significant difference (χ2= 1.05,P= 1.0) among the samples from 3 regions, which demonstrates the prevalent fungal contamination in the herbal medicines.
  
  
  CONCLUSIONS
  The prevalent contamination phenomenon of fungi and high potential risk of sterigmatocystin and ochratoxin A were observed in 45 medicinal herbs collected from China.
authors.affiliation: Research Centre of Chinese Herbal Resource Science and Engineering, Guangzhou University of Chinese Medicine, Guangzhou, China.|Key Laboratory of Chinese Medicinal Resource from Lingnan, Ministry of Education, Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: Run-Sheng
authors.initials: RS
authors.lastname: Zheng
authors.affiliation: Research Centre of Chinese Herbal Resource Science and Engineering, Guangzhou University of Chinese Medicine, Guangzhou, China.|Key Laboratory of Chinese Medicinal Resource from Lingnan, Ministry of Education, Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: Wen-Li
authors.initials: WL
authors.lastname: Wang
authors.affiliation: Research Centre of Chinese Herbal Resource Science and Engineering, Guangzhou University of Chinese Medicine, Guangzhou, China.|Key Laboratory of Chinese Medicinal Resource from Lingnan, Ministry of Education, Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Tan
authors.affiliation: Research Centre of Chinese Herbal Resource Science and Engineering, Guangzhou University of Chinese Medicine, Guangzhou, China.|Key Laboratory of Chinese Medicinal Resource from Lingnan, Ministry of Education, Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: Hui
authors.identifier: 0000-0002-6270-1596
authors.initials: H
authors.lastname: Xu
authors.affiliation: Research Centre of Chinese Herbal Resource Science and Engineering, Guangzhou University of Chinese Medicine, Guangzhou, China.|Key Laboratory of Chinese Medicinal Resource from Lingnan, Ministry of Education, Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: Ruo-Ting
authors.initials: RT
authors.lastname: Zhan
authors.affiliation: Research Centre of Chinese Herbal Resource Science and Engineering, Guangzhou University of Chinese Medicine, Guangzhou, China.|Key Laboratory of Chinese Medicinal Resource from Lingnan, Ministry of Education, Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: Wei-Wen
authors.initials: WW
authors.lastname: Chen