Objective:To learn about the genotyping of human Brucella isolated from Sichuan Province. Methods:BCSP31-PCR and AMOS-PCR were used to identify the genus and biotype of the 66 strains isolated from confirmed human brucellosis cases in Sichuan Province from 2014 to 2020, respectively. The isolated strains were genotyped by multi-locus sequence typing (MLST)-9. The sequence type (ST) was compared trough the online MLST database. A minimum spanning tree (MST) was constructed to cluster the newly discovered and known ST using the BioNumerics software version 7.6.Results:The 66 strains isolated from human cases of brucellosis in Sichuan Province from 2014 to 2020 were Brucella, and 65 of them were Brucella melitensis while one strain was Brucella abortus. The MLST method identified three known STs (ST-8, ST-39 and ST-2) and one newly type (ST-101). Among them, ST-8 was the main ST in Sichuan Province (90.91%, 60/66), another 4 strains of Brucella melitensis were ST-39, and 1 strain of Brucella abortus was ST-2. The newly type ST-101 was isolated from Leshan City in 2019, belonging to the Brucella melitensis and closely related to the evolution of ST-8. Conclusion:Brucella melitensis is the main epidemic Brucella strain in Sichuan Province, ST-8 is predominant genotype, with a small amount of ST-39, ST-101 and ST-2.

OBJECTIVE: To establish an ultra-high performance liquid chromatography-tandem mass spectrometry(HPLC-MS) method for simultaneous detection of 12 kinds of rodenticides such as tetramine, warfarin and rodenticide in suspected poisoning patients' residual food, vomit, gastric lavage, serum and urine. METHODS: The residual food, vomit, gastric lavage, serum and urine of patients with suspected rodenticide poisoning were collected. The food, vomit, gastric lavage and urine samples were added with ammonium acetate at a concentration of 2 mol/L, and than were repeatedly extracted twice by ethyl acetate. The serum sample was extracted by adding acetonitrile. After the sample was dried by nitrogen, it was dissolved in methanol ∶ammonium acetate(60 ∶40, V/V), and the supernatant was centrifuged and separated by a C18 column, and quantified by a standard curve method. Samples were detected by HPLC-MS. RESULTS: The linearity of the 12 kinds of rodenticides in the quantitative range of residual food, vomit, gastric lavage, serum and urine in patients with suspected rodenticide poisoning was good, and the correlation coefficient was 0.992 3-0.999 9. The detection limit of food, vomit or gastric lavage was 0.03-0.14 μg/kg, and that in serum and urine were 0.10-0.30 and 0.02-0.04 μg/L, respectively. The standard recovery rate was 84.4%-114.0%, and the within-run and between-run relative standard deviations were 2.7%-6.2% and 2.4%-9.5%, respectively.CONCLUSION: The method has advantages of simple operation, high efficiency and good accuracy. This method is suitable for emergency treatment of poisoning events caused by rodent drugs or poisoning.