TABLE 5.

Agreement between isoniazid susceptibility as determined by MABA and rifampin susceptibility as determined by MABA and PCR-UHG-Rif, respectively

Isoniazid susceptibilityc	Rifampin susceptibility as determined by:
	MABAa		PCR-UHG-Rifb
	Susceptible	Resistant	Susceptible	Resistant
Susceptible	451	28	448	31
Resistant	72	137	63	146

^aStrains were considered resistant to rifampin when rifampin MICs were > 1.0 μg/ml as determined by MABA (5, 19). Agreement, 85.4%; κ, 0.6347; P, <0.0001.

^bSamples determined susceptible by PCR-UHG-Rif were those presenting the same heteroduplex pattern as M. tuberculosis H37Rv on acrylamide gels. Agreement, 86.3%; κ, 0.6624; P, <0.0003.

^cStrains were considered resistant to isoniazid when isoniazid MICs were > 0.5 μg/ml as determined by MABA (5, 19).