Differences in cell wall thickness between resistant and nonresistant strains of Mycobacterium tuberculosis: using transmission electron microscopy.
The ultrastructure of the cell wall of extensively drug-resistant (XDR), multidrug-resistant (MDR) and susceptible tuberculosis (TB) bacilli was viewed under transmission electron microscopy (TEM). Under the TEM, marked differences were observed in the thickness of their cell wall: 20.2 +/-1.5 and 17.1 +/-1.03 nm for the XDR and MDR TB bacilli, respectively, and 15.6 +/- 1.3 nm for the susceptible isolates (p < 0.05). In MDR bacilli, thickening of the cell wall was observed in the intermediate electron-transparent layer (ETL) and outer electron-opaque layer, whereas in XDR TB cells the basal peptidoglycan layer was denser and almost fused with the ETL. Five to seven percent of XDR TB bacilli had the appearance of the stationary phase with cell wall thickness ranging from 21 to 26 nm (p < 0.001). Information provided in this study is of significant importance in terms of drug selection for effective treatment of resistant strains.
Velayati
Ali Akbar
AA
Mycobacteriology Research Centre, National Research Institute of Tuberculosis and Lung Disease (NRITLD), WHO Collaborating Centre, Shahid Beheshti University, Tehran, Iran.
Farnia
Parissa
P
Ibrahim
Tengku Azmi
TA
Haroun
Rafiuz Zaman
RZ
Kuan
Ho Oi
HO
Ghanavi
Jalaledin
J
Farnia
Poopak
P
Kabarei
Ali Naghee
AN
Tabarsi
Payam
P
Omar
Abdul Rahman
AR
Varahram
Mohammad
M
Masjedi
Mohammad Reza
MR
D002473:Cell Wall / Q000648:ultrastructure*; D024881:Drug Resistance, Bacterial / Q000502:physiology*; D046529:Microscopy, Electron, Transmission; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000648:ultrastructure*