Asmar S, Chatellier S, Mirande C, van Belkum A, Canard I, Raoult D, Drancourt M
Aix Marseille Université, URMITE, UMR CNRS 7278, IRD 198, Inserm 1095, Marseille, France.
bioMérieux SA, Innovation Unit, La Balme Les Grottes, France.
J Clin Microbiol. 2015 Aug;53(8):2566-9. doi: 10.1128/JCM.01149-15. Epub 2015 Jun 3.
The laboratory diagnosis of tuberculosis usually relies on culture-based isolation of the causative Mycobacterium tuberculosis bacteria. We developed and evaluated the performance of MOD9, a new blood-free derivative of the MOD4 solid medium on which we previously reported for the isolation and culture of mycobacteria. First, inoculation of Lowenstein-Jensen medium with 21 M. tuberculosis isolates at 10(5), 10(3), and 10 CFU yielded colonies in 5.7 ± 1.5 days, 7.6 ± 0.8 days, and 10.8 ± 1.7 days versus 1.5 ± 0.4 days, 3.5 ± 0.6 days, and 4.9 ± 1 days in MOD9 (P < 0.05, Student's t test). Further, the time to detectable growth of M. tuberculosis was measured on MOD9 and Lowenstein-Jensen media after duplicate inoculation of 250 clinical specimens decontaminated with 0.7% chlorhexidine. The contamination rate was 1.6% (4/250) on MOD9 versus 4.4% (11/250) on Lowenstein-Jensen medium (P = 0.11, Fisher's exact test). Chlorhexidine-MOD9 yielded 38/250 (15.2%) isolates versus 32/250 (12.8%) isolates for the chlorhexidine-LJ (P = 0.5195, Fisher's exact test). All together, eight M. tuberculosis isolates were cultured solely from chlorhexidine-MOD9, and two M. tuberculosis isolates were cultured solely from chlorhexidine-LJ. The time to detection was 9.8 ± 3.9 (range, 5 to 18) days for chlorhexidine-MOD9 versus 17.4 ± 5.9 (range, 10 to 35) days for chlorhexidine-LJ (P < 0.05, Student's t test). These data indicate the superiority of the MOD9 medium over the standard LJ medium following chlorhexidine decontamination for the recovery of M. tuberculosis.
结核病的实验室诊断通常依赖于通过培养来分离致病的结核分枝杆菌。我们研发并评估了MOD9的性能，它是MOD4固体培养基的一种新的无血衍生物，我们之前曾报道过用其来分离和培养分枝杆菌。首先，在罗-琴培养基上接种21株结核分枝杆菌，接种量分别为10⁵、10³和10 CFU，其菌落生长时间分别为5.7±1.5天、7.6±0.8天和10.8±1.7天，而在MOD9上分别为1.5±0.4天、3.5±0.6天和4.9±1天（P<0.05，Student t检验）。此外，在用0.7%氯己定净化后的250份临床标本进行重复接种后，在MOD9和罗-琴培养基上测量结核分枝杆菌可检测到生长的时间。MOD9的污染率为1.6%（4/250），而罗-琴培养基为4.4%（11/250）（P = 0.11，Fisher精确检验）。氯己定-MOD9培养出38/250（15.2%）的菌株，而氯己定-罗-琴培养出32/250（12.8%）的菌株（P = 0.5195，Fisher精确检验）。总共，8株结核分枝杆菌仅从氯己定-MOD9中培养出来，2株结核分枝杆菌仅从氯己定-罗-琴中培养出来。氯己定-MOD9的检测时间为9.8±3.9（范围5至18）天，而氯己定-罗-琴为17.4±5.9（范围10至35）天（P<0.05，Student t检验）。这些数据表明，在氯己定净化后，用于结核分枝杆菌回收的MOD9培养基优于标准的罗-琴培养基。
