LC Identification Methods for MTB/Isolated Mycobacteria

LC Identification Methods for MTB/Isolated Mycobacteria

Learning Objectives

List methods to identify MGIT growth as MTB that differentiates it from other contaminants

Content

The following observations can make tentative identification:

Rate of growth: Generally, M. tuberculosis, M. bovis and, to some extent, M. Kansasii are slow growers and take a longer time to turn positive in an MGIT tube as compared to other non tuberculous mycobacteria (NTM).
Nature of turbidity: In liquid medium, M. tuberculosis appears as granular or flaky growth, while most NTM form uniform slight turbidity (except M. kansasii).
Smear examination: M. tuberculosis forms typical clumps and serpentine cords, while other mycobacteria appear as loose, smaller clumps and cording single cells. M. kansasii may be difficult to differentiate as it is morphologically closer to M. tuberculosis.
Lateral flow immunochromatography (Capilia TB Test): Used to differentiate M. tuberculosis from NTM.
Other methods: For complete speciation, other biochemical tests can be used.

Resource

Assessment

Question 1	Answer 1	Answer 2	Answer 3	Answer 4	Correct Answer	Correct Explanation	Page id	Part of Pre-Test	Part of Post-Test
The majority of mycobacterial species grow well at 37°C ± 1ºC.	True	False			True	Most mycobacterial species grow well at 37°C ± 1ºC; however, some may require temperatures other than 37°C.		Yes	Yes
Question 2
The reagents for decontamination can be used, which were prepared one month back.	True	False			False	It is better to use freshly prepared reagents.		Yes	Yes

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