Nontuberculous mycobacteria isolated during the treatment of pulmonary tuberculosis.
BACKGROUND
The significance of nontuberculous mycobacteria (NTM) isolated from a patient during therapy for pulmonary tuberculosis (TB) is uncertain. We investigated the frequency and clinical significance of NTM isolated from patients receiving anti-TB treatment.


METHODS
We conducted a retrospective cohort study of all patients with culture-confirmed pulmonary TB, and identified patients with respiratory cultures positive for NTM during therapy for pulmonary TB.


RESULTS
From January 2003 to December 2005, 958 patients were diagnosed with culture-confirmed pulmonary TB. NTM were isolated from 113 specimens in 68 (7.1%) patients during anti-TB treatment. The most frequently isolated NTM species were Mycobacterium abscessus (n=35, 31%), Mycobacterium fortuitum (n=17, 15%), Mycobacterium avium complex (n=9, 8%), and Mycobacterium gordonae (n=9, 8%). Forty-eight (71%) patients had only one positive culture, while 20 (29%) had two or more positive cultures for NTM. Only two (3%) patients who had two or more positive culture after anti-TB treatment showed the same NTM species, which were M. abscessus.


CONCLUSIONS
The isolation of NTM in patients with pulmonary TB is not uncommon during anti-TB treatment. However, this is likely the result of colonization, a transient infection, or specimen contamination. The co-existence of pulmonary TB and NTM lung disease may be rare but should be considered in patients with relatively virulent NTM species such as M. abscessus.
Jun
Hee-Jung
HJ
Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, Republic of Korea.
Jeon
Kyeongman
K
Um
Sang-Won
SW
Kwon
O Jung
OJ
Lee
Nam Yong
NY
Koh
Won-Jung
WJ
D000328:Adult; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009161:Mycobacterium / Q000302:isolation & purification*; D009165:Mycobacterium Infections, Nontuberculous / Q000382:microbiology*; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000382:microbiology* / Q000628:therapy