卡他莫拉菌快速鉴定的方法学及耐药性研究

A novel method for rapid identification and drug resistance of Moraxella catarrhalis

目的 建立快速鉴定卡他莫拉菌 (MC)的方法 ,对不同血源、营养配方的琼脂培养基进行了MC的生长指数 (GI)的测定 ,了解MC的耐药状况。方法 使用含 5 0 μg/ml万古霉素的兔血巧克力琼脂培养基分离MC ,以 3 乙酰吲哚纸片法检测MC产生的乙酰酯酶 ,与DNA酶试验为对照 ;将MC接种于 9种培养基上 ,计算和比较MC在 9种培养基上的平均GI;同时用Nitrocefin纸片检测MC的 β内酰胺酶发生率 ,以琼脂平皿二倍稀释法测定最低抑菌浓度 (MIC)。结果 检测 2 2 8株MC的乙酰酯酶结果 ,其敏感性为 10 0 % ,与 2 0 3株近缘菌比较特异性为 10 0 % ,与DNA酶试验有很高的相关性 ;MC在巧克力琼脂培养基上生长较血琼脂培养基好 ,但与GI值比较 ,差异无明显意义 (P >0 0 5 ) ;MC产 β内酰胺酶的阳性率为 93 0 % ;哌拉西林 /舒巴坦和哌拉西林 /他唑巴坦的MIC50 和MIC90 分别较单哌拉西林 ,降低了 8倍 ;氨苄西林 /舒巴坦的MIC50 和MIC90 较单氨苄西林降低了 32倍和 4倍。结论 用 3 乙酰吲哚纸片法检测MC产生的乙酰酯酶 ,是临床实验室快速鉴定MC的良好方法。MC产 β内酰胺酶阳性率之高 ,应引起临床医生的重视。哌拉西林 /舒巴坦、氨苄西林 /舒巴坦、头孢哌酮 /舒巴坦、哌拉西林 /他唑巴坦及亚胺培南 /西司他丁对

Objective To establish a novel method for rapid identification and drug resistance of Moraxella catarrhalis, Different sourses of blood and the formula of chocklate agars were detected the Growth Index(GI). Methods Moraxella catarrhalis from specimens contaminated by microbial flora were isolated with a choclate agar with 50 mg/L vancomycin (CHOC-V) method. Nine media were inoculated,on which GI were calculated and compared. beta-Lactamase were determined by nitrocefin slip method. Results 228 strains of Moraxella catarrhalis and 203 strains of recent limbus bacteria were examined. The sensitivity of this method was 100%,and the specificity was 100%. The GI of Moraxella catarrhalis on chocklate agars and blood agars was higher than that of the BCA, NUA, MHA ( P<0.05). beta-Lactamase positive rate in Moraxella catarrhalis was 93.0%. The MIC 50 and MIC 90 of PIPC/SBT and PIPC/TAZ against Moraxella catarrhalis were 8 times lower then PIPC.The MIC 50 and MIC 90 of AMP/SBT against Moraxella catarrhalis were 8 times lower then AMP. Conclusions This method is rapid, accurate and simple for identifying Moraxella catarrhalis. PIPC/SBT,CFP/SBT,PIPC/TAZ,AMP/SBT,IPM/CST showed high activity against Moraxella catarrhalis of beta-Lactamase positive.