TABLE 5.

Mutation sites in NTX^R E. coli indicate an efflux-mediated mode of resistance ^{a , b}

	mprA 2 (emrR)	emrA	emrB	marR	lon 2	envZ
Ec_M1	Leu95Pro	−49C > T	Ile480Leu		Asn417Lys	Val54Glu
Ec_M2	Leu95Pro	−49C > T	Ile480Leu		Asn417Lys	Val54Glu
Ec_M3	Leu151Pro	Ala5Ala c			Tyr141∆
Ec_M4	Glu55Stop				Gly359Arg	Ile86Ser Arg397Cys
Ec_M5		−11A > T			Ser101-Ala114	Val241Gly
Ec_M6	Leu151Pro Arg90Gly	Pro10Pro c			Leu175∆	Val54Glu Pro248Ala
Ec_M7	Glu55Stop			Asn89Thr
Ec_M8	Ala92Asp				Glu636Stop
Ec_M9	Glu55Stop				Asn417Lys	Ile86Ser
Ec_M10	Glu55Stop	Ala5Ala c		Ala70∆		Leu43Ile
Ec_M11	Glu55Stop				Asn417Lys	Ile86Ser
Ec_M12		Gln11Lys		Gly104Asp
Ec_M13	Glu55Stop				Asn417Lys	Arg397Cys

^a All mutants show an 8–16× reduced susceptibility to NTX.

^b ∆: deletion; Leu95Pro: single-nucleotide polymorphism with amino acid exchange as indicated; -49C>T: exchange of C to T 49 bp upstream of coding region.

^c Silent mutation.