TABLE 2.

Results of repeated tests for discordant results among LJ proportion method, BacT/ALERT 3D system, and PZase assay^a

Isolate	T/Ub	Result of initial test			Result(s) of repeat test				% Resistance on LJ medium
		LJ PMc	PZase assay	BacTd	LJ PM	PZase assay after 4 days	PZase assay after 10 days	BacT
7	T	S	−	S	S	−	−,e R	S	Nil
21	U	S	+	R	S	+, S	NDf	Rg	Nil
36	U	S	−	S	S	−	+, S	S	Nil
37	T	R	+	S	S	+, S	ND	S	0.7
42	T	S	−	S	S	−	+, S	S	Nil
74	T	R	+	R	R	+, S	ND	R	39
76	T	R	+	R	R	+, S	ND	R	40
79	T	R	+	R	R	+, S	ND	R	35
92	T	R	+	R	R	+, S	ND	R	30
103	T	R	+	R	R	+, S	ND	R	20
104	T	R	+	R	R	+, S	ND	R	55

^aR, resistant; S, susceptible; +, positive; −, negative.

^bT, treated case; U, untreated case.

^cLJ PM, Löwenstein-Jensen proportion method.

^dBacT, PZA susceptibility testing by the BacT/ALERT 3D system at a 100-μg/ml concentration.

^eNegative at the end of 20 days also.

^fND, not done if the tube at 4 days was positive.

^gResistant to a PZA concentration of 100 μg/ml but susceptible at 300 μg/ml.