革兰阳性菌引起的血培养阳性标本直接细菌鉴定和药敏的方法探讨

Discussion on methods for bacteria identification and drug sensitivity of blood-culture positive specimens caused by gram-positive bacteria

目的探讨革兰阳性菌引起的血培养阳性标本直接细菌鉴定和药敏的可行性。方法将血培养瓶放入Bact/Alert 3D全自动血培养仪中,阳性报警后涂片染色,选革兰阳性菌143份进行试验,抽取培养液,利用梯度离心法,用VITEK 2 Compact全自动鉴定药敏仪直接做鉴定和药敏试验。用传统法的鉴定和药敏结果对直接法的鉴定和药敏结果进行评估。结果 143株革兰阳性菌中包括金黄色葡萄球菌46株、溶血葡萄球菌33株、表皮葡萄球菌25株、人葡萄球菌20株、粪肠球菌11株、屎肠球菌8株,鉴定符合率分别为100%、97.0%、100%、85.0%、91.0%、87.5%,总符合率为97.1%。革兰阳性菌引起的血培养阳性标本药敏用直接法与传统法进行比较总符合率为96.4%,大部分药敏符合率>95.0%,非常重大错误率为0.1%,重大错误率0.7%。结论 Bact/Alert 3D全自动血培养仪阳性标本,涂片为染色革兰阳性菌梯度离心后直接用VITEK 2 Compact全自动鉴定药敏仪直接做鉴定和药敏试验是可行的,并可缩短临床报告时间,为临床诊断和治疗提供依据,有较高的应用价值。

Objective To discuss the feasibility of direct bacterial identification and drug sensitivity for gram positive bacteria in blood culture positive specimens.Methods The growth of microorganisms in blood culture bottle was screened by Bact/Alert3D automated blood culture system.One hundred and forty-three gram positive bacteria specimens were tested.Culture fluid was injected by using gradient centrifugation method.Direct identification and drug sensitivity was tested by VITEK 2 Compact automatic identification and drug sensitivity instrument.They were evaluated by traditional method for identification and drug sensitivity results.Results One hundred and forty-three strains of Gram-positive bacteria included 46 strains of Staphylococcus aureus,33 strains of Staphylococcus haemolyticus,25 strains of Staphylococcus epidermidis,20 strains of Staphylococals hominis,11 strains of Enterococcus faecalis,8 strains of Enterococcus faeclum.The coincidence rates of identification were100%,97.0%,100%,85.0%,91.0%,87.5%,The total coincidence rate of direct method and traditional method was96.4% for drug sensitivity test of blood culture specimens infected by gram-positive bacteria,and most drug sensitivity coincidence rates were greater than 95.0%.The non-significant error rate was 0.1%,while the significant error rate was 0.7%.Conclusion It is feasible for positive Bact/Alert 3D blood culture specimens with smear showing gram-positive bacteria to carry out direct identification and drug sensitivity test by VITEK 2 Compact automated instrument after gradient centrifugation,it can shorten the clinical report time and provide basis for clinical diagnosis and treatment,having high application value.