Kehrmann J, Stumpf A L, Dragaqina A, Buer J
Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
J Clin Microbiol. 2024 Sep 11;62(9):e0068324. doi: 10.1128/jcm.00683-24. Epub 2024 Aug 13.
This study evaluates the growth of mycobacteria in samples from cystic fibrosis (CF) patients and tissue samples using the mycobacteria growth indicator tube (MGIT) incubated at 30°C in comparison to conventional MGIT cultures incubated at 37°C in a BACTEC MGIT 960 device and solid media incubated at 36°C and 30°C. A total of 1,549 samples were analyzed, of which 202 mycobacterial isolates were cultured from 197 positive specimens, including five mixed cultures. The highest detection rate was achieved from MGIT at 30°C, with 84.2% of mycobacterial isolates (170 of 202), which was significantly higher than any other culture condition ( < 0.0001 for any condition). MGIT at 37°C yielded 61.4% (124 of 202) of the recovered isolates, whereas Löwenstein Jensen (LJ) and Stonebrink at 36°C, and LJ and Stonebrink at 30°C retrieved 47.0% (95), 49.5% (100), 50.0% (101), and 53.0% (107) of the isolates, respectively. Of the 53 isolates that were grown exclusively under one culture condition, the highest number of isolates (36) was recovered from MGIT incubated at 30°C. MGIT at 37°C recovered eight of the 53 isolates, whereas LJ incubated at 30°C and Stonebrink incubated at 30°C and 36°C recovered five, three, and one isolate, respectively. No isolates were grown exclusively from LJ incubated at 36°C. In CF patients and tissue samples, MGIT cultivated at 30°C for 8 weeks increases the performance of mycobacterial culture.
Our study shows that the addition of mycobacteria growth indicator tube (MGIT) liquid culture incubated at 30°C improves the detection of mycobacteria from CF and tissue samples. MGIT incubated at 30°C recovered significantly more mycobacterial isolates than MGIT incubated at 37°C and significantly more isolates than either Lowenstein Jensen or Stonebrink solid media incubated at either 36°C or 30°C. Of 202 mycobacterial isolates recovered from 1,549 specimens, 170 were recovered from MGIT incubated at 30°C, followed by MGIT incubated at 37°C with 124 isolates and solid media culture conditions that recovered between 95 and 107 mycobacterial isolates. All conventional culture conditions combined without MGIT incubated at 30°C recovered 166 isolates. MGIT incubated at 30°C recovered the highest number of isolates detected exclusively by a single culture condition and recovered mycobacterial isolates of highly relevant mycobacterial species, including and .
本研究评估了在30°C下使用分枝杆菌生长指示管（MGIT）培养囊性纤维化（CF）患者样本和组织样本中的分枝杆菌的生长情况，并与在BACTEC MGIT 960设备中于37°C培养的传统MGIT培养物以及在36°C和30°C培养的固体培养基进行比较。共分析了1549份样本，其中从197份阳性标本中培养出202株分枝杆菌分离株，包括5份混合培养物。在30°C下的MGIT检测率最高，分枝杆菌分离株中有84.2%（202株中的170株），这显著高于任何其他培养条件（任何条件下P<0.0001）。在37°C下的MGIT培养出了回收分离株的61.4%（202株中的124株），而在36°C下的罗-琴（LJ）培养基和斯通布林克培养基，以及在30°C下的LJ培养基和斯通布林克培养基分别培养出了分离株的47.0%（95株）、49.5%（100株）、50.0%（101株）和53.0%（107株）。在仅在一种培养条件下生长的53株分离株中，从在30°C下培养的MGIT中回收的分离株数量最多（36株）。在37°C下的MGIT回收了53株分离株中的8株，而在30°C下培养的LJ培养基以及在30°C和36°C下培养的斯通布林克培养基分别回收了5株、3株和1株分离株。在36°C下培养的LJ培养基中没有分离株单独生长。在CF患者和组织样本中，在30°C下培养8周的MGIT可提高分枝杆菌培养的性能。
我们的研究表明，添加在30°C下培养的分枝杆菌生长指示管（MGIT）液体培养物可提高从CF和组织样本中检测分枝杆菌的能力。在30°C下培养的MGIT回收的分枝杆菌分离株明显多于在37°C下培养的MGIT，且明显多于在36°C或30°C下培养的罗-琴或斯通布林克固体培养基。从1549份标本中回收的202株分枝杆菌分离株中，170株是从在30°C下培养的MGIT中回收的，其次是在37°C下培养的MGIT，回收了124株分离株，固体培养基培养条件回收了95至107株分枝杆菌分离株。所有不包括在30°C下培养的MGIT的传统培养条件总共回收了166株分离株。在30°C下培养的MGIT回收的仅由单一培养条件检测到的分离株数量最多，并且回收了高度相关分枝杆菌种的分枝杆菌分离株，包括[具体菌种1]和[具体菌种2]。
