血三株小牛葡萄球菌药敏及耐药机制的初步研究

目的 探讨患者血小牛葡萄球菌（Staphylococcus vitulinus）药敏及耐药机制.方法 用美国BD公司phoenixTM 100全自动细菌鉴定/药敏仪及其NMIC/ID-55鉴定/MIC药敏板对患者血分离的三株小牛葡萄球菌（菌株31937、32612、80708）进行鉴定和21种抗菌药物敏感性检测,应用NMIC/ID-55鉴定/药敏板头孢硝噻吩试验（nitrocefin test,NT）检测其β-内酰胺酶、大环内酯类耐药表型、莫匹罗星高度耐药表型.结果 phoenixTM 100细菌鉴定仪鉴定该三菌均为小牛葡萄球菌,可信度均为90%;3株小牛葡萄球菌药敏结果很相似,均对妥布霉素、阿米卡星、阿莫西林/克拉维酸、复方磺胺、万古霉素、替考拉宁、呋喃妥因、利福平（仅菌株80707耐药）、四环素、利奈唑胺、夫西地酸敏感,对庆大霉素、氨苄西林、青霉素、苯唑西林、红霉素、克林霉素、奎奴普丁、莫匹罗星、莫匹罗星高耐、环丙沙星等药耐药;3株菌NT试验均为阳性、MLSb耐药表型和莫匹罗星高耐.结论 本文这3株小牛葡萄球菌药敏结果均为多耐,其机制推测为产β-内酰胺酶、质粒编码mupA核心基因erm基因.经检索CNKI、CMCC、万方数据医药信息系统和PubMed数据库,本文是我国第一篇研究小牛葡萄球菌耐药机制报道（截止2013年4月9日）.

A preliminary study of drug sensitivity and resistance mechanisms in 3 blood strains of staphylococcus vitulinus

Objective To explore the drug sensitivity and resistance mechanisms of staphylococcus vitulinus from patient＇s blood. Methods Three strains of Staphylococcus vitulinus including strain 31937, strain 32612, and strain 80708 derived from patient＇s blood were identified by phoenixTM 100 automatic bacterial identification/drug susceptibil- ity instrument and NMIC/ID-55 identification/MIC drug susceptibility panel as well as the drug sensitivity test of 21 antibacterial agents. The ~3-1aetamase, and resistant phenotypes of maerolides and mupirocin were detected in nitro- cefin test （NT） by NMIC/ID-55 identification/drug sensitivity panel. Results Three strains of bacteria were all identi- fied as staphylococcus vitulinus by phoenixTM 100 bacterial identification instrument, and the reliability all reached up to 90%,, The outcomes of drug sensitivity test in 3 strains of staphylococcus vitulinus were extremely similar, they all susceptible to tobramycin, amikacin, amoxicillin/clavulanic acid, compound sulfanilamide, vancomycin, teicoplanin, macrodantin, rifampicin （only to 80708 strain）, tetracycline, linezolid, and fusidic acid. Besides, they were all resistant to gentamicin, ampicillin, penicillin, oxacillin, erythrocin, clindamycin, quinupristin, mupirocin, and ciprofloxacin. The NT tests of 3 strains were all positive, which displayed high resistances of maerolide-lincosamide-streptogramin B （MLSb） phenotype and mupirocin phenotype. Conclusion The drug sensitivity outcomes from these 3 strains of staphy- lococcus vitulinus in the article show multi-resistance, whose mechanism is speculated as 13-1actamase, plasmid code of mupA, and core gene of erm. After going through China national knowledge internet （CNKI）, China medical current contents （CMCC）, wanfang data, and PubMed database, we believe this is the first time to report the drug resistance mechanism of staphylococcus vitulinus in China before April 9th, 2013.