Table 1.

Divergence of long-term cultures after 24 weeks of incubation

Culture pair (A and B)*	Time of divergence† (weeks)	Drug marker(s) remaining‡
		Culture A	Culture B
1	2	Str	Nal and Str
2	2	Str	Nal and Str
3	2	Str	Str
4	4	Nal	Str
5	4	Nal	Nal
6	6	Nal	Nal and Str
7	6	Str	Str
8	8	Str	Str
9	10	Nal and Str	Nal
10	16	Nal	Nal

^*See Fig. 2A for description of the culture pair. 

^†Divergence was observed after the week indicated. 

^‡Limit of direction is <10² cfu ml⁻¹.