TABLE 1.

Characteristics of the bacterial isolates used

Isolate	Source	MIC (μg/ml)			Resistance mechanism(s)
		Minocyline	Minocyline + PAβNa	Polymyxin B
AB BAA 747	Laboratory	0.25	0.125	1	Reference adeB expression
AB 7283	Clinical	0.5	0.125	1	Moderate overexpressionb of adeB
AB 1261	Clinical	1	0.125	2	Moderate overexpression of adeB
AB 7416	Clinical	16	2	1	tetB, moderate overexpression of adeB

^aPAβN, Phe-Arg b-naphtylamide (100 μg/ml).

^bModerate overexpression, >10× the transcription level by qRT-PCR, compared to that in a wild-type isolate susceptible to minocycline.