Growth and cell-division in extensive (XDR) and extremely drug resistant (XXDR) tuberculosis strains: transmission and atomic force observation.
The ultra-structure of Mycobacterium tuberculosis (MTB) was examined by transmission electronic (TEM)) and atomic force microscopy (AFM). The study was performed to describe the morphology of susceptible, multidrug-resistant (MDR), extensively drug-resistant (XDR) and extremely drug-resistant tuberculosis isolates (XXDR-TB) during their exponential growth phase. Four types of cell division were observed and described. While three of them (symmetrical, asymmetrical and branching type) occurred in all isolates studied, the fourth one (adapted type) was seen only in XDR and XXDR-TB bacilli. In the fourth type of cell division, a rod shaped mother cell produced a small round shape bacillus (0.3-0.5 μm). These round cells were different from buds or polar division, but similar to terminal endospores without showing the typing heat resistance. Based on the present observation, we suggest that XDR-and XXDR-TB bacilli accommodate changes helping them to overcome the hostile environment. Viewed under AFM, the other frequently detected shapes in MTB isolates were oval, V, Y and multi-branching filaments. These shape variation confirmed pleomorphic phenomena in MTB populations and the specific features of pan-resistant strains.
Parissa
P
Farnia
Reza Masjedi
RM
Mohammad
Muayad Aghali
MA
Merza
Payam
P
Tabarsi
Gennadii Konstantinovich
GK
Zhavnerko
Tengku Azmi
TA
Ibrahim
Ho Oi
HO
Kuan
Jalladein
J
Ghanavei
Poopak
P
Farnia
Reza
R
Ranjbar
Nikolai Nikolaevich
NN
Poleschuyk
Leonid Petrovich
LP
Titov
Parviz
P
Owlia
Mehadi
M
Kazampour
Mohammad
M
Setareh
Muaryam
M
Sheikolslami
Giovanni Battista
GB
Migliori
Ali Akbar
AA
Velayati