Culture and identification method for mycobacteria

Abstract

The invention belongs to the technical field of culture and identification of mycobacteria, and particularly relates to a culture and identification method for mycobacteria. The method comprises the following steps: (1) selecting clinical positive phlegm specimens obtained after Ziehl-Neelsen staining, inoculating each specimen with a BD liquid culture medium, and carrying out BactecTM MGITTM 960 liquid culture; (2) when the specimens are reported to be positive, uniformly dispersing mycobacteria by using an ultrasonic bacterium dispersion counter, recording the turbidity of an original tube, and continuing to incubate for 1-3 days; and (3) finally, conducting Gram staining to confirm whether infectious microbes exist or not, and performing MALDI-TOF MS identification or DNA microarray chip process identification. According to embodiments of the invention, application of MALDI-TOF-MS to conventional identification of mycobacteria in a clinical microbiological laboratory is feasible, and the MALDI-TOF-MS has a good application prospect.

Description

technical field [0001] The invention belongs to the technical field of mycobacterium culture and identification, and in particular relates to a method for the culture and identification of mycobacteria. Background technique [0002] The clinical symptoms and imaging features of different species of mycobacterial infection are very similar, but they are often completely different in pathogenicity, drug sensitivity, and treatment options. Without accurate etiological evidence, misdiagnosis may result. Accurate pathogenic identification of species or even subspecies is of great significance for the diagnosis and treatment of mycobacteria. [0003] At present, laboratories at home and abroad mainly use liquid and solid methods to culture mycobacteria. Solid culture is the traditional Roche culture method, but it takes a long time, 4 to 6 weeks. The automated culture system used in the liquid culture system, such as BactecTM MGITTM 960 (BD Diagnostics, Sparks, Maryland, USA), ca...

AI Technical Summary

Problems solved by technology

The quality of ribosomal protein extraction directly affects the results of mass spectrometry identification. Due to the tough cell wall and high lipid content of mycobacteria, it is difficult to cleavage to obtain sufficient protein. Therefore, the sample needs to be pre-treated to obtain sufficient protein. However, different pre-treatment methods will It affects the identification ability of this method. Although there are related research reports at home and abroad on the application of MALDI-TOF MS to detect mycobacteria, the pretreatment method is mostly limited to solid culture.

Existing liquid extraction methods do not achieve high identification rates, and the steps are complicated and require multiple treatments

In addition, due to the potential interference of samples and liquid media, and the low number of positive bacteria, it is still difficult to accurately identify mycobacteria from liquid media.

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