European Society of Mycobacteriology - Instituto Nacional de Saúde ...

A REPORT ON NEW ADAPTED FORMS OF EXTENSIVELY DRUG RESISTANCE
TUBERCLE BACILLI : TRANSMISSION ELECTRON MICROSCOPY ANALYSIS
OP-19
Parissa Farnia(PhD)1. Ali Akbar Veleyati (MD)1, Mohammal Reza Masjedi (MD)1, 2 Tengku Azmi Ibrahim (PhD)2, Payam
Tabarsei (MD), Rafiuz Zaman Haroun (MSC)2, Ho Oi Kuan (MSC))2, Abdul Rahman Omar (PhD)1
1 - Mycobacteriology Research Centre, National Research Institute of Tuberculosis and Lung Disease (NRITLD), WHO
Collaborating Centre, Shahid Beheshti University (Medical Campus), Darabad, Tehran ,19556, P.O: 19575/154, Iran.
E-mail: pfarnia@hotmail.com
2 - Microscopic unit, Institute of Bioscience , University Putra Malaysia ,43400 UPM ,Serdang, Selangor Darul Ehsan , Malaysia
Background
Extensively drug resistance tuberculosis bacilli (XDR-TB), is caused by a strain of M. tuberculosis(MTB) that are resistant to
isoniazid and rifampin (which defines MDR tuberculosis) in addition to any fluroquinolone and at least one of the three
following injectable drugs: caperomycin, kanamycin and amikacin. Viewed under transmission electron microscopy (TEM),
spore like structure was observed inside the XDR-TB bacilli.
Methods
The susceptibility testing against first and second line drugs was performed on isolated M. tuberculosis strains. Subsequently,
a homogenous thick suspension of 10 7 to 10 8 cells at exponential phase was prepared and observed under Transmission
Electron Microscopy (TEM). Five isolates from each group (susceptible, MDR, and XDR TB) were used in this study.
Results
Viewed under the TEM, the XDRTB bacilli at exponential phase had three types of cell division 1) 80-70% of bacilli were
looks as norm one with symmetrical or asymmetrical cell division 2) 5-7% with extra ordinary thick cell wall ( 21 to 26
nm ) which was similar to stationary or dormant phase bacilli. But surprisingly the stationary phase XDR-TB bacilli were
at dividing process 3) 15-20% bacilli had spore formation inside them These spores were different from buds or a polar
division that formed during cell branching of MTB. No spore’s and stationary phase bacilli were detected in susceptible
or multidrug resistant strains of MTB.
Discussion
Dividing phenomena in XDR-TB bacilli with stationary phase appearance will generate new adapted types of M. tuberculosis
which can resist the effect of all available anti tuberculosis drugs. At the same time, it is possible that under certain
conditions, the XDR-TB bacilli produce spore to overcome the hostile environment. Spore formation in XDR-TB bacilli
should take very seriously from epidemiological point of view. With these new forms of adaptation that occurs in XDRTB
bacilli , how should we treat and control the diseases.
European Society of Mycobacteriology | 30 th Annual Congress | July 2009 | Porto - Portugal
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