Fédération de Microbiologie Clinique, Assistance Publique - Hôpitaux de Marseille, Marseille, France.
PLoS Negl Trop Dis. 2007 Nov 28;1(2):e83. doi: 10.1371/journal.pntd.0000083.
Mycobacterium species are grown using specific media that increase laboratory cost, thus hampering their diffusion in resource-limited countries. Preliminary data suggested that versatile blood agar may be also used for mycobacterial culture.
We examined the growth of 41 different Mycobacterium species on 5% blood agar. Over a 24-month period we analysed isolation of mycobacteria after parallel inoculation of clinical specimens into both a reference automated system (BACTEC 9000 MB broth) and 5% blood agar slant tubes, after NaOH decontamination, and compared the cost of performing 1,000 analyses using these two techniques.
Mycobacterium reference species cultured on blood agar, with the exception of Mycobacterium ulcerans. Inoculation of 1,634 specimens yielded 95 Mycobacterium isolates. Blood agar performed significantly more efficiently than BACTEC 9000 MB broth (94 vs 88 isolates, P = 0.03). Decontamination of Candida albicans in 5 specimens by addition of amphotericin B in blood agar yielded one more M. tuberculosis isolate that could not be isolated in BACTEC broth. Uneven distribution of time to culture positivity for M. tuberculosis had a median (range) of 19+/-5 days using blood agar and 26+/-6 days using BACTEC 9000 MB broth. Cost for 1,000 analyses in France was estimated to be of 1,913 euros using the blood agar method and 8,990 euros using the BACTEC 9000 MB method. Blood agar should be regarded as a first-line medium for culturing Mycobacterium species. It saves time, is cost-effective, is more sensitive than, and at least as rapid as the automated method. This is of particular importance for resource-limited countries in which the prevalence of tuberculosis is high.
分枝杆菌属的培养需要使用特定的培养基，这增加了实验室的成本，从而阻碍了它们在资源有限的国家的普及。初步数据表明，多功能血琼脂也可用于分枝杆菌培养。
我们检查了 41 种不同的分枝杆菌属在 5%血琼脂上的生长情况。在 24 个月的时间里，我们分析了在经过 NaOH 去污处理后，将临床标本同时接种到参考自动系统（BACTEC 9000 MB 肉汤）和 5%血琼脂斜管中，比较了使用这两种技术进行 1000 次分析的成本。
除了溃疡分枝杆菌外，分枝杆菌参考种在血琼脂上培养。接种 1634 个标本得到 95 个分枝杆菌分离株。血琼脂的效率明显高于 BACTEC 9000 MB 肉汤（94 与 88 株，P = 0.03）。在血琼脂中加入两性霉素 B 对 5 份白色念珠菌标本进行去污处理，多分离出一株不能在 BACTEC 肉汤中分离的结核分枝杆菌。结核分枝杆菌培养阳性时间的分布不均匀，使用血琼脂的中位数（范围）为 19+/-5 天，使用 BACTEC 9000 MB 肉汤的中位数（范围）为 26+/-6 天。在法国，使用血琼脂方法的 1000 次分析的成本估计为 1913 欧元，使用 BACTEC 9000 MB 方法的成本为 8990 欧元。血琼脂应被视为培养分枝杆菌属的首选培养基。它节省时间，具有成本效益，比自动化方法更敏感，并且与自动化方法一样快速。对于结核病高发的资源有限的国家来说，这一点尤其重要。
