Abstract
The motive or object of this study is to find out that NTM (Non tuberculous Mycobacteria) can grow on nutrient agar. Generally any agar media or any other media acts as a food source for the bacteria so that they can grow on that particular media. Our subject of discussion how NTMs grow on NA media and why Mycobacterium tuberculosis complex does not grows on NA.
Keywords: Nutrient agar, MTBC (Mycobacterium tuberculosis complex), NTM, tubercle, LJ
Introduction
it is known that there are types of Mycobacteria. One is tubercle forming and another one is non tuberculous. NTM also known as environmental mycobacteria atypical & Mycobacteria other than tuberculosis, which does not cause tuberculosis or leprosy. Normally we all have knowledge that Mycobacteria grow on LJ medium is normally involved for cultivation and isolation of Mycobacterium species. But between NTM & MTBC can grow on nutrient agar.
Epidemiology
The average prevalence of tuberculosis in India is 5.05 per thousand. And prevalence of smear positive cases are 2.27% per thousand and incidence of smear positive cases are 84 per ten thousand annually.
Classification of non-tuberculous Mycobacteria
Brief description on NTMs
|
Sl. No |
Photochromogen | Scotochorormogen | Rapid grower |
Non photochromogen |
| develop pigment following exposure to light and take more than 7 days to appear on media | Develop pigment after exposure to light or dark and tae more than 7 days | It appears on solid media less than 7 days | Non pigmented and take more than 7 days to appear on solid media
|
|
| Example | M. kansasii | M. scrofulaceum | M. fortuitum | M.avium |
Four main manifestations of tuberculosis
Tuberculosis is zoonotic disease and it has public health importance. Three stages of TB are: Exposure, Latent and Active diseases.
How NTMs grows on NA
NTM species culture has been prepared on solid media. From that media one loop full culture is again sub-cultured in middlebrook 7H9 media and incubated for 3 days or 72 hours. After completion of incubation one loop full bacteria is cultured on Nutrient Agar media. AS we know that mycobacteria cannot grow on NA but when NTMs cultured on NA, it produces the beaded colonies on NA. From this experiment we can conclude some of NTMs can produce colonies on NA. mainly all the bacteria grow on different particular media by taking the nutrition from that particular media. Like this, NTMs can take nutrition from nutrient agar and from colonies on NA.
Photos of colonies of NTMs on Nutrient Agar
Diagnosis
Non Mycobacterium tuberculous bacteria that can be grown on nutrient agar are identified by Z-N staining procedure. One loop full bacteria is taken from agar and it is stained through the whole procedure of Z-N staining.
Conclusion
We all are familiar with the zoonotic importance of Tuberculosis disease. If it is diagnosed properly then it can be prevented as well as treated properly. The epidemiology of diseases and surveillance programme about the disease can help to increase awareness among the people and animal owner. The above text or above information can change our concept about Mycobacteria. Non tuberculous Mycobacteria can grow on nutrient agar. These bacteria take this agar as a food source.
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