摘要
目的 评估不同药敏试验方法检测鲍曼不动杆菌和肺炎克雷伯菌对替加环素的体外药敏结果。方法 连续收集2012年1月至3月临床感染患者分离的50株耐碳青霉烯类鲍曼不动杆菌(CRAB)和49株肺炎克雷伯菌,采用微量肉汤稀释法、Vitek-2法、MIC Test Strip(MTS)法及纸片扩散法分别测定替加环素对两种细菌的敏感性,并以微量肉汤稀释法为参考方法,评估Vitek-2法、MTS法及纸片扩散法与参考方法的一致性。结果 按照美国食品药品监督局(FDA)的判断标准,微量肉汤稀释法、Vitek-2法和MTS法检测替加环素对CRAB和肺炎克雷伯菌的敏感性分别为94.0％/91.8％,68.0％/91.8％和90.0％/91.8％。对于CRAB,Vitek-2法和MTS法与参考方法的基本一致率/分类一致率(EA/CA)分别为94.0％/72.0％和92.0％/90.0％,66.0％ (33/50)的菌株Vitek-2法检测的MIC值比参考方法高1～2个稀释度,MTS法检测的MIC值存在32.0％ (16/50)偏高及22.0％ (11/50)偏低;对于肺炎克雷伯菌,Vitek-2法和MTS法与参考方法的EA/CA分别为95.9％/98.0％和83.7％/91.8％,36.7％ (18/49)的菌株Vitek-2法检测的MIC值比参考方法低1～3个稀释度,79.6％(39/49)的菌株MTS检测的MIC值比参考方法低1～3个稀释度。Vitek-2法和MTS法检测两种细菌均未出现重大误差(VME)和大误差(ME)。纸片扩散法与参考方法相比,对于CRAB,采用敏感/耐药(≥14 mm/≤10 mm)折点,CA为94.0％,高于Jones等推荐的折点(≥16 mm/≤12 mm,CA为82.0％);对肺炎克雷伯菌,采用敏感/耐药(≥14 mm/≤10 mm)折点,CA为93.9％,高于FDA中肠杆菌的折点(≥19 mm/≤14 mm,CA为67.3％)。结论 对于CRAB菌株,MTS法与微量肉汤稀释法的一致性较高,MIC结果存在一定程度的偏差;对于肺炎克雷伯菌,Vitek-2法与微量肉汤稀释法的一致性较高,MIC结果存在一定程度的偏低;纸片扩散法与微量肉汤稀释法一致性较低,针对不同细菌其判定折点需进一步研究。
Objective To compare different susceptibility testing methods of tigecycline against Acinetobacter baumannii and Klebsiella pneumoniae.Methods Fifty carbapenem-resietant A.baumannii (CRAB) strains and 49 K.pneumoniae strains were collected from Tianjin Medical University General Hospital during January and March 2012.Minimum inhibitory concentration (MIC) and inhibitory zone diameters for tigecycline were determined by broth microdilution,Vitek-2,MTS and disk diffusion methods.The results of Vitek-2,MTS and disk diffusion methods were compared with those of broth microdilution method.Results According to FDA standards,the susceptibilities of CRAB and K.pneumoniae to tigecycline determined by broth microdilution,Vitek-2 and MTS were 94.0％/91.8％,68.0％/91.8％ and 90.0％/91.8％,respectively.For CRAB isolates,the essential agreement (EA) and categorical agreement (CA) produced by Vitek-2 and MTS were 94.0％/72.0％ and 92.0％/90.0％.MICs determined by Vitek-2 were 1-2 dilutions higher than the reference method in 33 (66.0％) strains,and those determined by MTS were higher in 16 (32.0％) strains and lower in 11 (22.0％) strains.For K.pneumoniae isolates,the EA/CA produced by Vitek-2 and MTS were 95.9％/98.0％ and 83.7％/91.8％,respectively.MICs determined by Vitek-2 were 1-3 dilutions lower than the reference method in 17 (34.7％) strains,and those determined by MTS were 1-3 dilutions lower than the reference method in 39 (79.6％) strains.None of thetwo methods produced very major error (VME) and major error (ME) against two kinds of isolates.The results were determined by disk diffusion method using different breakpoints according different isolates.For CRAB,using ≥14 mm/≤ 10 mm as breakpoint,CA was 94.0％,which was higher than the breakpoint recommended by Jones et al (≥16 mm/≤12 mm,CA was 82.0％) ; and for K.pneumoniae,using the ≥ 14 mm/≤ 10 mm as breakpoint,CA was 93.9％,higher than the FDA Enterobacteriaceae breakpoint (≥ 19 mm/≤ 14 mm,CA was 67.3％).Conclusion For CRAB str
出处
《中华临床感染病杂志》
CAS
2013年第5期282-286,共5页
Chinese Journal of Clinical Infectious Diseases
