一株人血源猪链球菌的分子分型与耐药检测

Molecular typing and drug resistance testing of a Streptococcus suis strain isolated from human blood

目的对北京某医院就诊的一例人感染猪链球菌患者的血培养分离菌株,并进行分子分型与耐药检测分析。方法将患者血培养阳性物接种于哥伦比亚血琼脂平板,分离培养后提取菌株DNA,采用多位点序列分型(MLST)确定其分子型别;采用微量肉汤稀释法进行12种抗生素的药敏试验。结果该菌株的多位点序列分型为ST1型。药敏试验结果表明:该菌对青霉素、左氧沙星、美罗培南、万古霉素、克林霉素、头孢噻肟、利奈唑胺、红霉素和头孢吡肟9种常用抗生素敏感;对氧氟沙星中度敏感;对四环素和氯霉素耐药。结论该猪链球菌为ST1型,是引起脑膜炎的主要型别;对9种常用抗生素菌敏感,可做为临床治疗的参考用药。

Objective To identify and analyze the molecular type and drug resistance of a bacteria strain isolated from the blood of a patient with Streptococcus suis infection in a hospital of Beijing.Methods The positive blood culture of the patient was inoculated to the Columbia with sheep blood agar plate to gain the pure clone,the bacteria DNA was extracted,and the molecular type was identified by multi-locus sequence typing(MLST).The drug resistance test was carried out by broth microdilution method for 12 antibiotics.Results The isolated strain was identified as ST1 type of Streptococcus suis.The drug resistance test showed that it was sensitive to 9 antibiotics:penicillin,levofloxacin,meropenem,vancomycin,clindamycin,cefotaxime,linezolid,erythromycin and cefepime,and moderately sensitive to ofloxacin,but resistant to tetracycline and chloramphenicol.Conclusions This bacteria strain was Streptococcus suis ST1 type,a major type for causing the meningitis,and it was sensitive to 9 common antibiotics which could be used as an alternative for the treatment in clinic.