OBJECTIVE To investigate metagenomic sequencing in the identification and tracing of bacteria contaminating drugs, and evaluate its application value. METHODS Both metagenomic sequencing and isolation culturing were employed to identify and type bacteria in two batches of Chinese patent medicines and environmental samples from the testing laboratory. The metagenomic sequencing results were analyzed at the strain level using MetaPhlan and StrainSifter software. RESULTS The analysis revealed a substantial contamination of Bacillus cereus-like organisms in both medicines and environmental samples, with the presence of the same B. cereus-like strain in medicine B18 and environmental sample HJ2. Through isolation culturing, five B. cereus-like strains were obtained from the medicines and environment. A phylogenetic tree was constructed based on the gyrA and panC gene sequences amplified by B. cereus-specific PCR, and multilocus sequence typing (MLST) results, all of which demonstrated that the B. cereus-like strain in medicine B18 belonged to the same group as one strain from the environment. CONCLUSION These findings indicate that metagenomic sequencing technology is reliable and has advantage over isolation culturing in comprehensively detecting potentially hazardous bacterial species and accurately performing strain-level traceability analysis. It holds significant application value in identification and tracing of pharmaceutical contamination.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |