Williams-Bouyer N, Yorke R, Lee H I, Woods G L
Department of Pathology, University of Texas Medical Branch, Galveston, Texas 77555-0740, USA.
J Clin Microbiol. 2000 Nov;38(11):4167-70. doi: 10.1128/JCM.38.11.4167-4170.2000.
The performances of two continuously monitoring mycobacterial culture systems-ESP Culture System II (ESP II; Trek Diagnostics, Inc. , Westlake, Ohio) and BACTEC MGIT 960 (BD Biosciences, Sparks, Md. )-were compared. In addition to both liquid media, all specimens were plated onto Middlebrook 7H11/7H11 selective agar. A total of 3, 151 specimens of all types (56.3% were respiratory specimens) were cultured; 231 (7.3%) yielded mycobacteria. The most common species recovered were Mycobacterium avium complex (69 isolates) and Mycobacterium tuberculosis complex (MTBC; 65 isolates). The recovery rates for ESP II, BACTEC MGIT 960, and Middlebrook agar, respectively, were 71.2, 63.9, and 61.8% for all mycobacteria; 70.2, 72.6, and 66.3% for all mycobacteria except Mycobacterium gordonae; and 73.8, 84.6, and 87.7% for MTBC. For liquid plus solid medium combinations, recovery rates for all mycobacteria and for MTBC, respectively, were 84.1 and 92.3% for ESP II plus Middlebrook agar and 81.5 and 98.5% for BACTEC MGIT 960 plus Middlebrook agar. The differences in recovery of all mycobacteria by ESP II and by BACTEC MGIT 960 were not significant; for the individual species, the only significant difference was recovery of more isolates of M. gordonae by ESP II. For those isolates recovered in both automated systems, mean times to detection of all mycobacteria and MTBC, respectively, were 15.8 and 17.4 days for ESP II and 12.5 and 11.9 days for BACTEC MGIT 960 (P < 0.05). False-positive signals occurred with 23 (0.7%) BACTEC MGIT 960 cultures and 84 (2.7%) ESP II cultures (P < 0.01). Overall contamination rates were 17.1% for BACTEC MGIT 960, 18.9% for ESP II, and 11.0% for Middlebrook agar. In summary, the ESP II and BACTEC MGIT 960 systems performed comparably with regard to growth and detection of mycobacteria, and the contamination rates were similar. However, with ESP II, times to detection of all mycobacteria and of MTBC were significantly longer, the recovery rate of M. gordonae was significantly higher, and the number of false-positive signals was greater than with BACTEC MGIT 960.
比较了两种持续监测分枝杆菌培养系统——ESP培养系统II（ESP II；Trek诊断公司，俄亥俄州韦斯特莱克）和BACTEC MGIT 960（BD生物科学公司，马里兰州斯帕克斯）的性能。除了两种液体培养基外，所有标本均接种于Middlebrook 7H11/7H11选择性琼脂平板上。共培养了3151份各类标本（56.3%为呼吸道标本）；231份（7.3%）培养出分枝杆菌。分离出的最常见菌种是鸟分枝杆菌复合体（69株）和结核分枝杆菌复合体（MTBC；65株）。对于所有分枝杆菌，ESP II、BACTEC MGIT 960和Middlebrook琼脂的回收率分别为71.2%、63.9%和61.8%；对于除戈登分枝杆菌外的所有分枝杆菌，回收率分别为70.2%、72.6%和66.3%；对于MTBC，回收率分别为73.8%、84.6%和87.7%。对于液体加固体培养基组合，ESP II加Middlebrook琼脂对于所有分枝杆菌和MTBC的回收率分别为84.1%和92.3%，BACTEC MGIT 960加Middlebrook琼脂对于所有分枝杆菌和MTBC的回收率分别为81.5%和98.5%。ESP II和BACTEC MGIT 960对所有分枝杆菌的回收率差异不显著；对于个别菌种，唯一显著的差异是ESP II分离出的戈登分枝杆菌更多。对于在两个自动化系统中均培养出的菌株，ESP II检测所有分枝杆菌和MTBC的平均时间分别为15.8天和17.4天，BACTEC MGIT 960检测所有分枝杆菌和MTBC的平均时间分别为12.5天和11.9天（P<0.05）。BACTEC MGIT 960培养物中有23份（0.7%）出现假阳性信号，ESP II培养物中有84份（2.7%）出现假阳性信号（P<0.01）。BACTEC MGIT 960的总体污染率为17.1%，ESP II为18.9%，Middlebrook琼脂为11.0%。总之，ESP II和BACTEC MGIT 960系统在分枝杆菌的生长和检测方面表现相当，污染率相似。然而，与BACTEC MGIT 960相比，ESP II检测所有分枝杆菌和MTBC的时间显著更长，戈登分枝杆菌的回收率显著更高，假阳性信号数量更多。
