TABLE 2.

Antimicrobial activity of VXc-486 against drug-resistant clinical isolates of M. tuberculosis from South Africa^a

Isolate	Genotype	Susceptibility status	Drug resistance profile	MIC (μg/ml) of VXc-486
TT135	Atypical Beijing	XDR	H, R, E, Z, ET, S, A, C, O, M, PAS	0.08
R179	Atypical Beijing	MDR	H, R, E, ET, S	0.08
R884	Low copy number	Pre-XDR	H, R, E, Z, ET, S, O	0.08
X_3	Beijing	XDR	H, R, E, K, S, C, O	0.68
X_27	Beijing	XDR	H, R, ET, O, A	0.68
X_60	Beijing	XDR	H, R, E, A, ET, O, S, C, K	0.68
X_61	Beijing	XDR	H, R, ET, A, O, K, S	0.68
X_131	F11	Pre-XDR	H, R, K, S, O	0.17
TT149	Atypical Beijing	XDR	H, R, ET, S, A, C, O, M	5.48

^aMycobacterial growth was measured by using mycobacterial growth indicator tubes (MGIT), and the MIC (μg/ml) of VXc-486 was determined. The growth units were recorded once the 1:100 controls reached a GU (gas unit) of 400, and the MIC is regarded as a concentration that gives a GU of 0. The isolates grew well in the presence of isoniazid, confirming resistance to this drug. Abbreviations: H, isoniazid; R, rifampin; E, ethionamide; ET, ethambutol; S, streptomycin; A, amikacin; C, capreomycin; O, ofloxacin; M, moxifloxacin; PAS, para-aminosalicylic acid; Z, pyrazinamide.