Research Note: Study on the antibacterial activity of Chinese herbal medicine against Aspergillus flavus and Aspergillus fumigatus of duck origin in laying hens.

Aspergillus flavus and Aspergillus fumigatus were derived and identified from the ducks infected with fungi. In order to investigate the effectiveness of Chinese herbal medicines against Aspergillus flavus and Aspergillus fumigatus, in vitro antibacterial test and animal infection control test were conducted to study the antibacterial activity of the Chinese medicine mixture which was compatible with Acorus gramineus, Phellodendron chinensis, and Cassia obtusifolia. According to the results, the liver of chickens infected with Aspergillus flavus and Aspergillus fumigatus displayed granulomatous lesions, indicating that the isolation of pathogen from the lungs of sick ducks is also pathogenic to chickens. As suggested by the results of in vitro drug sensitivity test, the mixture 1 MIC was the minimum, the MIC of Aspergillus flavus was 16 μg/μL, and the MIC of Aspergillus fumigatus was 4 μg/μL. In a petri dish of the same concentration, the colony diameter of Aspergillus flavus and Aspergillus fumigatus in Mixture 1 was the minimum. Besides, Aspergillus flavus colonies grew when the concentration was 64 μg/μL, and Aspergillus fumigatus colonies grew when the concentration was 4 μg/μL, which suggests the more significant inhibitory effect of Mixture 1 on Aspergillus flavus and Aspergillus fumigatus. According to the results of animal experiments, there was a significantly lower activity level of Glutamic oxaloacetic transaminase (GOT) and Glutamate pyruvic transaminase (GPT) in the protection group and the treatment group than in the bacterial infection group. As indicated by the blood smear results, there were more neutrophils in the infected group than in the prevention group and the treatment group. Thus, it can be seen from that the Mixture 1 produced preventive and therapeutic effects on the chickens infected with Aspergillus flavus and Aspergillus fumigatus.