Kamm W, Wenger A, Bille J
Institut de Microbiologie, Université de Lausanne, Centre Hospitalier Universitaire, Vaudois, Switzerland.
J Clin Microbiol. 1989 Jan;27(1):102-5. doi: 10.1128/jcm.27.1.102-105.1989.
A direct antimicrobial susceptibility test and a direct identification of positive blood culture broths for gram-negative rods confirmed with Gram stain by using a new instrument, Cobas-Bact, were compared with the conventional Kirby-Bauer agar diffusion disk method and with the in-house set of identification or API 20E, respectively. The bacterial pellet of centrifuged positive blood culture broth was used to inoculate a Cobas-Bact susceptibility and identification rotor. Bacteria from 206 cases of monomicrobial septicemia due to members of the family Enterobacteriaceae were tested. In 198 episodes (96%), direct identification and antimicrobial susceptibility testing results were obtained for the same bacterial pathogen within 5 h of detection. Of 204 direct identifications obtained, 177 (86.6%) were "high-confidence" correct identifications (percentage of likelihood [P] greater than or equal to 80%) and 25 (12.5%) "low-confidence" correct identifications (P less than 80%), whereas only 2 misidentifications occurred (1 Escherichia coli and 1 Proteus mirabilis). Direct susceptibility testing was performed in 199 episodes (96%), providing 1,885 antibiotic-microorganism combinations. Full agreement reached 86.3%, and essential agreement reached 92.8%. Minor discrepancies were found in 120 (6.5%) of the tests, major discrepancies were found in 127 (6.8%) tests, and very major discrepancies were found in only 7 (0.4%) tests. Subsequent MIC determinations in cases of major or very major discrepancies reduced the number of major discrepancies involving cephalosporins from 60 to 16, whereas all those involving aminoglycosides remained. Overall, this direct and rapid Cobas-Bact identification and susceptibility testing procedure offered accurate information with 5 to 6 h after the laboratory detection of bacteremia and septicemia due to members of the Enterobacteriacease.
使用新型仪器Cobas-Bact对革兰氏阴性杆菌进行直接药敏试验以及对经革兰氏染色确认的阳性血培养肉汤进行直接鉴定，并分别与传统的 Kirby-Bauer 琼脂扩散纸片法以及内部鉴定方法或 API 20E 进行比较。将离心后的阳性血培养肉汤的细菌沉淀用于接种Cobas-Bact药敏和鉴定转子。对206例由肠杆菌科成员引起的单微生物败血症病例的细菌进行了检测。在198例（96%）病例中，在检测后5小时内获得了针对同一细菌病原体的直接鉴定和药敏试验结果。在获得的204次直接鉴定中，177次（86.6%）为“高可信度”正确鉴定（可能性百分比[P]大于或等于80%），25次（12.5%）为“低可信度”正确鉴定（P小于80%），而仅出现2次错误鉴定（1株大肠杆菌和1株奇异变形杆菌）。在199例（96%）病例中进行了直接药敏试验，提供了1885种抗生素-微生物组合。完全一致率达到86.3%，基本一致率达到92.8%。在120次（6.5%）试验中发现了轻微差异，在127次（6.8%）试验中发现了主要差异，仅在7次（0.4%）试验中发现了非常主要的差异。在出现主要或非常主要差异的病例中随后进行的最低抑菌浓度测定，使涉及头孢菌素的主要差异数量从60例减少到16例，而所有涉及氨基糖苷类的差异仍然存在。总体而言，这种直接快速的Cobas-Bact鉴定和药敏试验程序在实验室检测到由肠杆菌科成员引起的菌血症和败血症后5至6小时内提供了准确信息。
