VITEK2.Compact对奶牛乳源金黄色葡萄球菌的条件摸索及MRSA检测结果准确性的评价

Conditions and Accuracy Verification of Automatic Microbial Antimicrobial Detection Method of Staphylococcus aureus

为探究金黄色葡萄球菌全自动微生物检测平台(VITEK2 Compact)检测条件,及该方法在金黄色葡萄球菌耐药性筛查的准确性及其兽医临床应用价值,以金黄色葡萄球菌ATCC 29213为质控菌株,选取ASTGP79药敏板,参考美国临床实验室标准研究所(CLSI/NCCLS)的《抗生素敏感试验操作标准》(S100-17和M31-A2)中兽医临床抗生素敏感性试验选药原则,通过摸索不同稀释浓度菌液,对照药敏标准,摸索全自动微生物生长分析仪的高通量筛选平台的适用检测条件。将该耐药性筛查方法应用于在奶牛乳汁中分离获得的39株金黄色葡萄球菌,与经典K-B法的耐药性进行比较,以此验证VITEK2 Compact检测金黄色葡萄球菌药敏结果准确性。结果显示,综合考虑检测结果、透光度、重复性等因素,确定了质控菌株的菌液比例为1×10^(8)CFU/mL,且证实了VITEK2 Compact药敏检测方法的结果符合临床折点的判断标准;对39株乳源金黄色葡萄球菌的耐药性检测与K-B法比较,标准符合率(CA):β-内酰胺类为92.30%、氨基糖苷类为93.32%、四环素类为92.30%、磺胺类为94.87%、喹诺酮类为92.30%、大环内酯类为90.59%、林可酰胺类为92.30%、氯霉素类为94.87%;两种检测方法对耐甲氧西林金黄色葡萄球菌(meticillin-resistant Staphylociccus aureus,MRSA)的检出阳性率无统计学差异(P>0.05)。表明了本研究探讨的金黄色葡萄球菌全自动微生物检测平台的药敏检测方法的准确性与可靠性,为该方法应用于金黄色葡萄球菌引起的奶牛乳房炎防治提供了理论依据。

In order to study the detection conditions of Staphylococcus aureus fully automatic microbial detection platform(VITEK2 Compact)and compare them with the K-B method,the accuracy of this method in S.aureus antimicrobial screening and its veterinary clinical application value were discussed.In this study,we used S.aureus ATCC 29213 as control and AST-GP79 plate,refer to the veterinary antibiotic susceptibility test standard(S100-17 and M31-A2)of CLSI/NCCLS to study the applicable testing conditions for the high-throughput screening platform of automatic microbial growth analyzer.The antimicrobial screening method was applied to 39 S.aureus strains isolated in dairy milk and compared with the classical K-B method to verify the accuracy of VITEK2 Compact for S.aureus susceptibility detection.Considering the test results,transmittance,reproducibility and other factors,the liquid proportion of control was 1×10^(8)CFU/mL and confirmed that the results of VITEK2 Compact antimicrobial susceptibility detection method met the judgment criteria of clinical discount point.Compared with K-B method,the results showed that criterion agreement(CA):β-lactam 92.30%,aminoglycosides 93.32%,tetracyclines 92.30%,sulfonamides 94.87%,quinolones 92.30%,macrolides 90.59%,lincoamides 92.30%,and chloramphenicol 94.87%;the positive rates of meticillin-resistant Staphylociccus aureus(MRSA)was not statistically different(P>0.05).It shows the accuracy and reliability of the antimicrobial susceptibility detection method of the fully automatic S.aureus microbial detection platform,and provides a theoretical basis for the application of this method to the prevention and treatment of clinical dairy cow mastitis caused by S.aureus.