Evaluating the clinical significance of nontuberculous mycobacteria isolated from respiratory samples in Iran: an often overlooked disease

Figures & data

Figure 1 Population study flowchart.

Abbreviations: TB, tuberculosis; MTC, Mycobacterium tuberculosis complex; NTM-LD, nontuberculous mycobacteria lung disease; ATS, American Thoracic Society.

Table 1 Clinical characteristic of patients infected with NTM isolates

Factors	NTM positive patients (n=53)
Mean age ± SD	52.9±13.8
Gender
Male	28 (52.8%)
Female	25 (47.2%)
History of smoking
Smokers	16 (30.2%)
Non-smokers	37 (69.8%)
Symptoms
Cough	49 (92.5%)
Sputum	45 (84.9%)
Fever	45 (84.9%)
Weight loss	35 (66.1%)
Night perspiration	32 (60.4%)
Gastroesophageal	26 (49.1%)
Dyspnea	18 (33.9%)
Hemoptysis	12 (22.6%)
Underlying disease
HIV	8 (15.1%)
Cystic fibrosis	6 (11.3%)
Diabetes mellitus	5 (9.4%)
NTM sample location
Sputum	45 (84.9%)
Bronchoalveolar lavage	8(15.1%)
AFB smear microscopy
Positive	12 (22.6%)
Negative	41 (77.4%)
Radiographic findings
Bronchiectasis	26 (49.1%)
Infiltrate	19 (35.8%)
Cavitary	10 (18.9%)
Consolidation	9 (17.1%)
NTM isolates
M. fortuitum	31 (58.5%)
M. simiae	12 (22.6%)
M. kansasii	6 (11.3%)
M. gordonae	2 (3.8%)
M. conceptionense	2 (3.8%)

Abbreviations: NTM, nontuberculous mycobacteria; AFB, acid-fast bacilli.

Table 2 Patients properties based on NTM isolates

Factors	M. fortuitum (n=31)	M. simiae (n=12)	M. kansasii (n=6)	M. gordonae (n=2)	M. conceptionense (n=2)	P-value
Mean age ± SD	52.9±14.2	62.5±9.8	42.5±11.8	46.0±5.7	44.0±9.9	0.345
Gender						0.039*
Male	19 (61.3%)	2 (16.7%)	4 (66.7%)	1 (50.0%)	2 (100.0%)
Female	12 (38.7%)	10 (83.3%)	2 (33.3%)	1 (50.0%)	0 (0.0%)
History of smoking						0.424
Smokers	12 (38.7%)	2 (16.7%)	1 (16.7%)	1 (50.0%)	0 (0.0%)
Non-smokers	19 (61.3%)	10 (83.3%)	5 (83.3%)	1 (50.0%)	2 (100.0%)
Underlying disease						0.888
HIV	6 (19.4%)	1 (8.3%)	0 (0.0%)	0 (0.0%)	1 (50.0%)
Cystic fibrosis	4 (12.9%)	1 (8.3%)	1 (16.7%)	0 (0.0%)	0 (0.0%)
Diabetes mellitus	2 (6.5%)	2 (16.7%)	1 (16.7%)	0 (0.0%)	1 (50.0%)
NTM sample location						0.605
Sputum	28 (90.3%)	10 (83.3%)	5 (83.3%)	1 (50.0%)	1 (50.0%)
Bronchoalveolar lavage	3 (9.7%)	2 (16.7%)	1 (16.7%)	1 (50.0%)	1 (50.0%)
AFB smear microscopy						0.739
Positive	8 (25.8%)	2 (16.7%)	1 (16.7%)	1 (50.0%)	0 (0.0%)
Negative	23 (74.2%)	10 (83.3%)	5 (83.3%)	1 (50.0%)	2 (100.0%)
Radiographic findings						0.013*
Bronchiectasis	17 (54.8%)	5 (41.7%)	1 (16.7%)	2 (100.0%)	1 (50.0%)
Infiltrate	6 (19.4%)	9 (75.0%)	2 (33.3%)	1 (50.0%)	1 (50.0%)
Cavitary	2 (6.5%)	1 (8.3%)	6 (100.0%)	0 (0.0%)	1 (50.0%)
Consolidation	3 (9.7%)	4 (33.3%)	1 (16.7%)	1 (50.0%)	0 (0.0%)

Note: *Statistically significant (P< 0.05).

Abbreviations: NTM, nontuberculous mycobacteria; AFB, acid-fast bacilli.

Figure 2 Symptoms of patients infected with nontuberculous mycobacteria (NTM) isolates.

Table S1 Antimycobacterial susceptibility testing results for clinical isolates of RGM

Bacteria (no.) and antimicrobial agent		MIC (µg/mL)		No. (%) of isolates
	Range	50%	90%	Susceptible	Intermediate	Resistant
M. fortuitum (31)
Isoniazid	2–>256	>256	>256	0 (0.0%)	0 (0.0%)	31 (100.0%)
Rifampicin	1–>256	128	>256	0 (0.0%)	0 (0.0%)	31 (100.0%)
Ethambutol	32–>256	256	>256	0 (0.0%)	0 (0.0%)	31 (100.0%)
Streptomycin	8–>256	32	128	0 (0.0%)	0 (0.0%)	31 (100.0%)
Amikacin	0.06–16	1	8	28 (90.3%)	2 (6.5%)	1 (3.2%)
Ofloxacin	0.06–32	2	8	15 (48.4%)	4 (12.9%)	12 (38.7%)
Ciprofloxacin	0.06–8	0.25	2	15 (48.4%)	4 (12.9%)	12 (38.7%)
Capreomycin	0.03–2	0.5	2	14 (45.2%)	7 (22.6%)	10 (32.2%)
M. conceptionense (2)
Isoniazid	16–>256	>256	>256	0 (0.0%)	1 (50.0%)	1 (50.0%)
Rifampicin	2–8	1	8	0 (0.0%)	1 (50.0%)	1 (50.0%)
Ethambutol	128–>256	>256	>256	0 (0.0%)	0 (0.0%)	2 (100.0%)
Streptomycin	4–64	32	64	0 (0.0%)	0 (0.0%)	2 (100.0%)
Amikacin	0.25–>32	16	64	2 (100.0%)	0 (0.0%)	0 (0.0%)
Ofloxacin	0.03–8	0.5	8	2 (100.0%)	0 (0.0%)	0 (0.0%)
Ciprofloxacin	0.13–8	2	4	2 (100.0%)	0 (0.0%)	0 (0.0%)
Capreomycin	0.03–32	2	16	1 (50.0%)	1 (50.0%)	0 (0.0%)

Abbreviations: MIC, minimum inhibitory concentrations; RGM, rapid-growing mycobacteria.

Table S2 Antimycobacterial susceptibility testing results for clinical isolates of SGM

Bacteria (no.) and antimicrobial agent		MIC (µg/mL)		No. (%) of isolates
	Range	50%	90%	Susceptible	Intermediate	Resistant
M. simiae (12)
Isoniazid	16–128	32	64	0 (0.0%)	0 (0.0%)	12 (100.0%)
Rifampicin	0.5–128	2	8	1 (8.3%)	0 (0.0%)	11(91.7%)
Ethambutol	4–64	16	64	3 (25.0%)	0 (0.0%)	9 (75.0%)
Streptomycin	2–64	16	32	2 (16.7%)	0 (0.0%)	10 (83.3%)
Amikacin	0.06–64	2	16	10 (83.3%)	0 (0.0%)	2 (16.7%)
Ofloxacin	2–64	8	32	1 (16.7%)	0 (0.0%)	10 (83.3%)
Ciprofloxacin	0.25–64	8	32	3 (25.0%)	0 (0.0%)	9 (75.0%)
M. kansasii (6)
Isoniazid	0.25–16	2	4	6 (100.0%)	0 (0.0%)	0 (0.0%)
Rifampicin	0.125–16	2	8	6 (100.0%)	0 (0.0%)	0 (0.0%)
Ethambutol	0.25–64	2	4	5 (83.3%)	0 (0.0%)	1 (16.7%)
Streptomycin	0.5–32	8	32	4 (66.7%)	0 (0.0%)	2 (33.3%)
Amikacin	0.125–32	2	16	1 (16.7%)	0 (0.0%)	5 (83.3%)
Ofloxacin	0.25–4	1	2	2 (33.3%)	0 (0.0%)	4 (66.7%)
Ciprofloxacin	0.25–16	2	4	2 (33.3%)	0 (0.0%)	4 (66.7%)
M. gordonae (2)
Isoniazid	0.5–>256	2	>256	1 (50.0%)	0 (0.0%)	1 (50.0%)
Rifampicin	0.125–16	0.25	8	0 (0.0%)	0 (0.0%)	2 (100.0%)
Ethambutol	0.5–64	1	16	1 (50.0%)	0 (0.0%)	1 (50.0%)
Streptomycin	0.25–32	1	8	1 (50.0%)	0 (0.0%)	1 (50.0%)
Amikacin	0.5–128	2	32	0 (0.0%)	0 (0.0%)	2 (100.0%)
Ofloxacin	1–32	2	16	1 (50.0%)	0 (0.0%)	1 (50.0%)
Ciprofloxacin	0.125–16	0.5	8	0 (0.0%)	0 (0.0%)	2 (100.0%)

Abbreviations: MIC, minimum inhibitory concentrations; SGM, slow-growing mycobacteria.