TABLE 2.

Frequency of transformation of S. pneumoniae R6 to evernimicin resistance with whole chromosomal DNA from four selected spontaneous mutants and their parent strains at different drug concentrations

Donor DNA	Time (h)	Transformation frequency at evernimicin concn (μg/ml)a:
		0.03	0.06	0.125	0.25
ATCC 49619	24	NG	NG	NG	NG
	48	tntc	1 × 10−6	NG	NG
	72	tntc	tntc	NG	NG
ATCC 49619-1	24	1.3 × 10−5 pp	NG	NG	NG
	48	tntc	6.1 × 10−5	2.0 × 10−6	NG
	72	tntc	tntc	2.2 × 10−5	2.0 × 10−6
ATCC 49619-2	24	1.8 × 10−5 pp	NG	NG	NG
	48	tntc	4.5 × 10−5	2.0 × 10−6	NG
	72	tntc	tntc	4.0 × 10−5	1.0 × 10−6
SP#3	24	NG	NG	NG	NG
	48	tntc	NG	NG	NG
	72	tntc	tntc	NG	NG
SP#3-1	24	6.0 × 10−6 pp	NG	NG	NG
	48	tntc	3.8 × 10−5	NG	NG
	72	tntc	tntc	2.5 × 10−5	3.0 × 10−6
SP#3-2	24	NG	NG	NG	NG
	48	tntc	1.6 × 10−5	NG	NG
	72	tntc	tntc	4.0 × 10−6	NG

^aAbbreviations: NG, no growth; tntc, too numerous to count; pp, pinprick colonies.