Comparative evaluation of the MGIT™ and BACTEC culture systems for the recovery of Mycobacterium avium subsp paratuberculosis from milk
Comparative evaluation of the MGIT™ and BACTEC culture systems for the recovery of Mycobacterium avium subsp paratuberculosis from milk
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DOI：
10.1046/j.1365-2672.2003.02003.x
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发表时间：
2003-01-01
影响因子：
4
通讯作者：
Rowe, MT
中科院分区：
文献类型：
--
作者：
Grant, IR;Kirk, RB;Rowe, MT
目的：比较非放射性MGIT（TM）（分枝杆菌生长指示管）和放射性BACTEC 460 TB培养系统（Becton Dickinson，Cowley，Oxford，UK）回收鸟分枝杆菌亚种的检测能力。方法和结果：超热处理（UHT）的牛奶样品加标不同水平的M。将副结核杆菌（10-10（7）个细胞ml（-1））接种到MGIT和BACTEC培养基（含有推荐的补充剂）中，用0.75%（w/v）氯化十六烷基吡啶对乳样品进行5小时的预先化学净化。对于每个培养系统，记录检测生长的时间（天），并且M.使用公开的公式从BACTEC读数计算每个乳样品的副结核菌计数。MGIT和BACTEC检测时间之间的相关性为0.6983。两种培养系统均能够检测10-100 M。未进行化学去污处理时，30-40 d内乳汁中副结核杆菌细胞数可达10 ~（2）~ 10 ~（3）cells ml（-1），而在培养前进行化学去污处理时，乳汁中副结核杆菌细胞数可达10 ~（2）~ 10 ~（3）cells ml（-1）以上。从牛奶中去除副结核杆菌而不损失检测灵敏度。培养前的化学去污导致活M.所有加标乳汁样品中均存在副结核杆菌，导致两种培养系统的检测能力降低。
Aims: To compare the detection capabilities of the non-radiometric MGIT(TM) (Mycobacteria Growth Indicator Tubes) and radiometric BACTEC 460TB culture systems (Becton Dickinson, Cowley, Oxford, UK) for recovering Mycobacterium avium subsp. paratuberculosis from milk.Methods and Results: Ultra heat treated (UHT) milk samples spiked with different levels of M. paratuberculosis (10-10(7) cells ml(-1)) were inoculated into MGIT and BACTEC media (containing recommended supplements) with and without prior chemical decontamination of the milk samples with 0.75% (w/v) cetylpyridinium chloride for 5 h. Time for the detection of growth in days was recorded for each culture system, and a M. paratuberculosis count for each milk sample was calculated from BACTEC readings using a published formula. Correlation between MGIT and BACTEC detection times was 0.6983. Both culture systems were capable of detecting 10-100 M. paratuberculosis cells ml(-1) in milk within 30-40 days when no decontamination treatment was applied, but only 10(2)-10(3) cells ml(-1) or greater when chemical decontamination was applied before culture.Conclusions, Significance and Impact of Study: The non-radiometric MGIT system could be substituted for the radiometric BACTEC system for the culture of M. paratuberculosis from milk without loss of detection sensitivity. Chemical decontamination before culture caused a significant reduction in numbers of viable M. paratuberculosis in all spiked milk samples resulting in decreased detection capability for both culture systems.