Drug resistance patterns of Mycobacterium tuberculosis in Riyadh, Saudi Arabia.
OBJECTIVE
To determine the rate and type of anti-tuberculosis drug resistance at King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.


METHODS
Review of microbiology and infection control databases for all patients with culture-positive Mycobacterium tuberculosis between June 1981 and May 2003 at the hospital. BACTEC 460TB radiometry then MGIT 960 were used for both mycobacterial detection and antimicrobial susceptibility testing.


RESULTS
A total of 764 M. tuberculosis isolates were obtained from 764 patients. Resistance to first-line agents (isoniazid, rifampicin, ethambutol and streptomycin) was noted in 65 (8.5%). Resistance to isoniazid was the highest, noted in 54 (7.1%); resistance to rifampicin, streptomycin and ethambutol was found in respectively 21 (2.7%), 29 (3.8%) and 12 (1.6%) isolates. Polyresistance was noted in eight (1%) isolates and monoresistance in 38 (5%) isolates. Multidrug-resistant M. tuberculosis was found in 19 (2.5%) isolates. There were 54 primary resistant isolates (7.6%), and 11 (22%) with acquired resistance. The median age of patients with resistant isolates was 38 years compared to 48 years for patients with sensitive isolates (P = 0.002).


CONCLUSIONS
Resistance to first-line anti-tuberculosis agents and multidrug-resistant M. tuberculosis remain relatively low in Saudi Arabia.
Section of Pediatrics Infectious Diseases, Department of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
F N S
FN
Kordy
S
S
Al-Thawadi
A A
AA
Alrajhi
D000995:Antitubercular Agents / Q000494:pharmacology*; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D012529:Saudi Arabia / Q000453:epidemiology; D018088:Tuberculosis, Multidrug-Resistant / Q000453:epidemiology* / Q000517:prevention & control
D000995:Antitubercular Agents