OBJECTIVE To establish the microbial limit test method and investigate the microbial contaminatioin status of TCM decoction pieces of new “Zhebawei”(Dendrobium officinale, Citrus changshan-huyou, Lindera aggregata, Tetrastigma hemsleyanum, Rubus chingii, Peucedanum praeruptorum, Ganoderma lucidum, Crocus sativus).

METHODS The suitability test of the method was carried out according to the general rule 1108 microbial limit test method for TCM decoction pieces of the fourth part of Chinese Pharmacopoeia(2025 Edition). The total aerobic count(TAC), total combined yeast and mold count(TYMC), total heat-resistant microbial count(HRMC), bile-tolerant Gram-negative bacteria(BTGB), Escherichia coli and Salmonella in TCM decoction pieces of new “Zhebawei” were determined. The strains of bacteria isolated from the controlled bacteria plate were identified by 16S rDNA sequencing technology.

RESULTS The suitability test of microbial counting method for TCM decoction pieces of new “Zhebawei” was carried out by the plate method, and the recovery rate was between 0.5 and 2. The suitability test of the controlled bacteria examination method was carried out by direct inoculation method, and the added test bacteria could be effectively detected. Because of the loose and bubbly texture of Ganoderma lucidum, Crocus sativus, they were easy to absorb water and expand, which was not convenient for the leaching of microorganisms on the surface of the decoction pieces and subsequent sampling. Therefore, they were prepared into 1∶20 test solution when conducting microbial counting, and the trypticase soy broth was increased to 200 mL during Salmonella test. For the 40 batches of samples, the lgTAC ranged from 1.18 to 6.00, and the lgTYMC ranged from 0.50 to 5.92. The detection rates of heat-resistant bacteria and BTGB were 52.5% and 67.5% respectively. Moreover, the BTGB exceeded 10⁴ cfu·g⁻¹ in 3 batches of samples. Escherichia coli and Salmonella were not detected in any of the samples. However, opportunistic pathogens such as Cronobacter sakazakii, Klebsiella pneumoniae, and Enterobacter aerogenes were identified.

CONCLUSION It is simple and reliable by using the conventional method to check the microbial limit for TCM decoction pieces of new “Zhebawei”. The detection of various opportunistic pathogens indicated that the TCM decoction pieces of new “Zhebawei” have a certain risk of disease, and it is suggested to improve the evaluation standard of microbial limit according to the classification of the decoction pieces.