目的 从广东疑似流行性脑脊髓膜炎婴儿脑脊液中分离出细菌并进行基因分型、耐药等鉴定。方法 从脑脊液分离菌株，进行染色镜检、生化鉴定、血清分型、基因组测序和药敏试验。结果 分离菌株在血平板上为灰白色菌落，镜检为无荚膜、无芽孢的革兰阴性短杆菌；生化反应及质谱结果符合沙门菌特性，血清型为4,12:i:1,2。全基因组测序结果显示，该菌株为鼠伤寒沙门菌，多位点序列分型为ST-19；分离菌株对头孢噻肟、氨苄西林、氨曲南、环丙沙星等10种药物均耐药。结论 从1例婴儿病例脑脊液分离到1株鼠伤寒沙门菌，对多种抗生素耐药。

Objective To isolate bacteria from cerebrospinal fluid of an infant suspected of epidemic cerebrospinal meningitis from Guangdong Province and to conduct genotype typing and drug resistance test.Methods The bacteria was isolated from cerebrospinal fluid and cultivated,and morphology observation, biochemical identification, serotype identification, genetic sequencing analysis and drug susceptibility test were conducted.Results The isolate showed greyish-white colonies on blood agar plates and appeared as non-capsulated, non-spore-forming, Gram-negative bacilli under the microscope. The results of biochemical reaction and mass spectrum identification of the isolated strain matched the characteristics of Salmonella and the serotype was 4,12:i:1,2. Genome sequencing implied that the strain was S.typhimurium, which belonged to the ST-19 group by multilocus sequence typing. The isolated S.typhimurium showed resistance to 10 antibiotics including cefotaxime, ampicillin, aztreonam, ciprofloxacin, etc.Conclusion S.typhimurium is isolated from the cerebrospinal fluid of an infant diagnosed as meningitis, and the isolate shows multi-drug resistance.