. 2020 Aug 24;9(9):534. doi: 10.3390/antibiotics9090534

Table 2.

Susceptibility to fosfomycin according to the Clinical and Laboratory Standards Institute (CLSI) procedure and supplemented with sodium phosphonoformate (PPF); bacterial growth on M9 minimal medium agar supplemented with sn-glycerol 3-phosphate (G3P) or glucose-6-phosphate (G6P); and amino acid substitutions in MurA, GlpT, UhpT, UhpA, PtsI, and CyaA proteins in 29 clinical isolates of Escherichia coli.

Strain	Fosfomycin Disk ¹	Clinical Category ²	Fosfomycin Disk Plus PPF ³	G3P ⁴	G6P ⁵	Amino Acid Substitutions in
Strain	Fosfomycin Disk ¹	Clinical Category ²	Fosfomycin Disk Plus PPF ³	G3P ⁴	G6P ⁵	MurA	GlpT	UhpT	UhpA	PtsI	CyaA
11	6	R	6	+	−	None	Leu297Phe Glu443Gln Gln444Glu Glu448Lys	Not detected	Not detected	Arg367Lys	Asn142Ser Ala349Glu Ser352Thr Ser356Leu Gly359Glu Glu362Asp
17	6	R	6	+	−	None	Glu448Lys	Glu350Gln	Not detected	Val25Ile Arg367Lys	Asn142Ser Asp837Glu Thr840Ala
26	12	R	12	+	− ^a	None	Gly84Asp Glu448Lys	Not detected	None	Arg367Lys	Asn142Ser Ala349Glu Ser356Leu Gly359Glu Glu362Asp Ala363Ser Asp837Glu Thr840Ala
66	6	R	13	+	−	None	Glu448Lys	Glu350Gln	Not detected	Val25Ile Arg367Lys	Asn142Ser Asp837Glu Thr840Ala
302	29	S	30	+	+	None	Glu448Lys	None	None	Arg367Lys	Asn142Ser Gly222Ser
334	31	S	32	+	+	None	Glu448Lys	None	None	Arg367Lys	Asn142Ser
381	6	R	6	+	−	None	Glu448Lys	Glu350Gln	Not detected	Val25Ile Arg367Lys	Asn142Ser Asp837Glu Thr840Ala
387	6	R	6	+	−	None	Glu448Lys	Glu350Gln	Not detected	Val25Ile Arg367Lys	Asn142Ser Asp837Glu Thr840Ala
462	12	R	13	+	−	None	Glu448Lys	Glu350Gln	Not detected	Val25Ile Arg367Lys	Asn142Ser Asp837Glu Thr840Ala
632	6	R	6	+	−	None	Leu297Phe Glu443Gln Gln444Glu Glu448Lys	Glu350Gln	Not detected	Arg367Lys	Asn142Ser Ala349Glu Ser352Thr Ser356Leu Gly359Glu Glu362Asp Ala363Gly
751	30	S	32	+	+	None	Ala16Thr Glu448Lys	None	Arg46Cys	Ala306Thr Arg367Lys	Asn142Ser Ala349Glu Ser356Leu Gly359Glu Glu362Asp Asp837Glu Thr840Ala
752	11	R	11	+	−	None	Pro212Leu Glu448Lys	Glu350Gln	Not detected	Val25Ile Arg367Lys	Asn142Ser Asp837Glu Thr840Ala
757	6	R	6	+	− ^a	None	Leu297Phe Glu443Gln Gln444Glu Glu448Lys	None	Not detected	Arg367Lys	Asn142Ser Ala349Glu Ser352Thr Ser356Leu Gly359Glu Glu362Asp
776	12	R	12	+	− ^a	None	Glu448Lys	Glu350Gln	Not detected	Val25Ile Arg367Lys	Asn142Ser Asp837Glu Thr840Ala
789	6	R	6	+	−	Leu370Ile	Leu297Phe Glu443Gln Gln444Glu Glu448Lys	Glu350Gln	Not detected	Arg367Lys	Asn142Ser Ala349Glu Ser352Thr Ser356Leu Gly359Glu Glu362Asp
792	6	R	6	+	−	None	Glu448Lys	Glu350Gln	Not detected	Val25Ile Arg367Lys	Asn142Ser Asp837Glu Thr840Ala
795	6	R	6	+	−	None	Leu297Phe Glu443Gln Gln444Glu Glu448Lys	Glu350Gln	Not detected	Arg367Lys	Asn142Ser Ala349Glu Ser352Thr Ser356Leu Gly359Glu Glu362Asp
797	20	S	21	+	+	None	Ala16Thr Leu373Arg Glu448Lys	None	Arg46Cys	Ala306Thr Arg367Lys	Asn142Ser Ala349Glu Ser356Leu Gly359Glu Glu362Asp Asp837Glu Thr840Ala
799	6	R	7	+	−	None	Leu297Phe Glu443Gln Gln444Glu Glu448Lys	None	Not detected	Arg367Lys	Asn142Ser Ala349Glu Ser352Thr Ser356Leu Gly359Glu Glu362Asp
802	30	S	30	+	+	None	Phe133Cys Gly135Trp Ala197Val Glu448Lys	None	None	Arg367Lys	Asn142Ser
809	6	R	6	+	−	Leu370Ile	Leu297Phe Glu443Gln Gln444Glu Glu448Lys	Glu350Gln	Not detected	Arg367Lys	Asn142Ser Ala349Glu Ser352Thr Ser356Leu Gly359Glu Glu362Asp
853	6	R	8	+	−	Leu370Ile	Leu297Phe Glu443Gln Gln444Glu Glu448Lys	Glu350Gln	Not detected	Arg367Lys	Asn142Ser Ala349Glu Ser352Thr Ser356Leu Gly359Glu Glu362Asp
854	6	R	6	+	−	None	Glu448Lys	None	Not detected	Arg367Lys	Asn142Ser
860	6	R	7	+	−	None	Met52Leu Leu297Phe Glu443Gln Gln444Glu Glu448Lys	None	Not detected	Arg367Lys	Asn142Ser Ala349Glu Ser352Thr Ser356Leu Gly359Glu Glu362Asp
871	6	R	14	+	− ^a	None	Leu297Phe Glu443Gln Gln444Glu Glu448Lys	Glu350Gln	Not detected	Arg367Lys	Asn142Ser Ala349Glu Ser352Thr Ser356Leu Gly359Glu Glu362Asp Ala363Gly
872	35	S	35	+	+	None	Glu448Lys	None	None	Arg367Lys	Asn142Ser Asp837Glu Thr840Ala
883	11	R	12	+	−	None	Glu448Lys	Glu350Gln	Not detected	Val25Ile Arg367Lys	Asn142Ser Asp837Glu Thr840Ala
891	11	R	11	+	−	None	Glu448Lys	Glu350Gln	Not detected	Val25Ile Arg367Lys	Asn142Ser Asp837Glu Thr840Ala
892	21	S	21	+	+	None	Glu448Lys	None	None	Arg367Lys	Asn142Ser

¹ Diameter (in mm) of the bacterial growth inhibition halo around the disk with 200 μg fosfomycin supplemented with 50 μg glucose-6-phosphate on Mueller-Hinton agar. ² Clinical categories of each isolate against fosfomycin according to CLSI breakpoints (S: susceptible; R: resistant). ³ Diameter (in mm) of the bacterial growth inhibition halo around the disk with 200 μg fosfomycin supplemented with 50 μg glucose-6-phosphate and 20 μL sodium phosphonoformate (PPF) in order to identify E. coli isolates producing fosfomycin resistance-mediating glutathione S-transferases (between-diameter difference of ≥5 mm considered to confirm the phenotypic presence of the enzyme). ⁴ Bacterial growth on M9 minimal medium agar supplemented with 0.2% sn-glycerol 3-phosphate (all isolates showed growth). ⁵ Bacterial growth on M9 minimal medium agar supplemented with 0.2% glucose-6-phosphate (+: bacterial growth; −: absence of bacterial growth). ^a Only poor growth was observed after 48 h of incubation. Not detected: gene not detected by PCR after the different combinations of two pairs of primers (loss of the entire gene). None: no amino acid substitutions found.