TABLE 2.

Criteria used to predict ciprofloxacin MICs and resistance/susceptibility phenotypes for clinical isolates

Gene variantsa	Corresponding PAO1 mutants	Predicted MIC (predicted ciprofloxacin resistance phenotype)b
No analyzed variants in gyrA, parC, nfxB, gyrB, or parE	-	Less than 1 (S)
Wild-type gyrA and variant parC, nfxB, gyrB, parE, or have crpP genec	parC S87L	Less than 1 (S)
	parE V460G
	nfxB T39P
	gyrB d
gyrA D87N	gyrA D87N	0.25 (S)
gyrAT83I	gyrA T83I	1 (I)
gyrAT83I + parC	gyrAT83I + parCS87L	4 (R)
gyrAT83I + parE	gyrAT83I + parEV460G	2 (R)
gyrAT83I + nfxB	gyrAT83I + nfxBT39P	1 (I)
gyrAT83I + nfxB + parE/parC	gyrAT83I + nfxB T39P + parCS87L	2–4 (R)

^aVariants are as listed in Table 1.

^bCriteria to predict MICs were based on MICs of equivalent engineered mutants (Table S1). S, susceptible; I, intermediate; R, resistant. The MICs are given in mg/liter.

^cPlasmid-borne gene (29).

^dReference 15.