Table 1.

Involvement of tet(O) in tetracycline resistance.

		MIC # (mg/L)
Species	Tet(O) *	≤4	8	16	32	64	128	256	≥512	Sum
C. jejuni	+	0	0	3	3	24	50	9	14	103
	-	26	2	0	0	0	0	0	1	29
C. coli	+	0	0	0	1	1	0	3	1	6
	-	1	0	0	0	0	0	0	0	1

^# Minimal inhibitory concentration. * Presence or absence of tet(O) as revealed by PCR with specific primers [25]. Degenerated primers [26] were used to screen, by PCR, all strains lacking tet(O), among which only HCC30 (Table S1) was positive.