High Resolution Melting Analysis for Rapid Mutation Screening in Gyrase and Topoisomerase IV Genes in Quinolone-Resistant Salmonella enterica

Table 1

Mutations in the gyrase and topoisomerase IV genes as determined by DNA sequencing and the nalidixic acid minimum inhibitory concentration (MIC) of their corresponding Salmonella strains.

Strain	MIC (μg/mL)		gyrB	parC
SE 109/07	>256	D87Y	Silent mutations	None	V521F
SE 005/03	>256	D87Y	Silent mutations	None	Silent mutations
SE 022/03	>256	D87Y	Silent mutations	None	Silent mutations
SE 026/03	>256	D87Y	Silent mutations	None	Silent mutations
SE 027/03	>256	D87Y	Silent mutations	None	Silent mutations
SE 028/03	>256	D87Y	Silent mutations	None	Silent mutations
SE 032/03	>256	D87Y	Silent mutations	None	Silent mutations
SE 033/03	>256	D87Y	Silent mutations	None	Silent mutations
SE 047/04	>256	D87Y	Silent mutations	None	Silent mutations
SE 054/05	>256	D87Y	Silent mutations	None	Silent mutations
SE 064/05	>256	D87Y	Silent mutations	None	Silent mutations
SE 066/05	>256	D87Y	Silent mutations	None	Silent mutations
SE 067/05	>256	D87Y	Silent mutations	None	Silent mutations
SE 069/05	>256	D87Y	Silent mutations	None	Silent mutations
SE 073/05	>256	D87Y	Silent mutations	None	Silent mutations
SE 075/05	>256	D87Y	Silent mutations	None	Silent mutations
SE 078/05	>256	D87Y	Silent mutations	None	Silent mutations
SE 080/05	>256	D87Y	Silent mutations	None	Silent mutations
SE 081/05	>256	D87Y	Silent mutations	None	Silent mutations
SE 086/06	>256	D87Y	Silent mutations	None	Silent mutations
SE 101/07	>256	D87Y	Silent mutations	None	Silent mutations
SE 104/07	>256	D87Y	Silent mutations	None	Silent mutations
SE 105/07	>256	D87Y	Silent mutations	None	Silent mutations
SE 106/07	>256	D87Y	Silent mutations	None	Silent mutations
SE 107/07	>256	D87Y	Silent mutations	None	Silent mutations
SE 002/03	192	D87Y	Silent mutations	None	Silent mutations
SE 076/05	192	D87Y	Silent mutations	None	Silent mutations
SE 004/03	128	D87Y	Silent mutations	None	Silent mutations
SE 048/04	128	D87Y	Silent mutations	None	Silent mutations
SE 097/06	128	D87Y	Silent mutations	None	Silent mutations
SE 074/05	96	D87Y	Silent mutations	None	Silent mutations
SE 090/06	96	D87Y	Silent mutations	None	Silent mutations
SE 068/05	64	D87Y	Silent mutations	None	Silent mutations
SE 102/07	64	D87Y	Silent mutations	None	Silent mutations
SE 046/04	48	D87Y	Silent mutations	None	Silent mutations
SE 049/04	48	D87Y	Silent mutations	None	Silent mutations
SE 084/05	24	D87Y	Silent mutations	None	Silent mutations
SE 001/03	16	D87Y	Silent mutations	None	Silent mutations
SE 065/05	16	D87Y	Silent mutations	None	Silent mutations
STM 032/04	>256	D87G	None	None	None
SE 089/06	>256	D87G	Silent mutations	None	Silent mutations
SE 095/06	>256	D87G	Silent mutations	None	Silent mutations
SE 070/05	128	D87G	Silent mutations	None	Silent mutations
SE 050/04	64	D87G	Silent mutations	None	Silent mutations
SE 012/03	>256	D87N	Silent mutations	None	Silent mutations
SE 015/03	>256	D87N	Silent mutations	None	Silent mutations
SE 013/03	96	D87N	Silent mutations	None	Silent mutations
STM 043/05	>256	S83F	Silent mutations	Silent mutations	Silent mutations
SE 055/05	>256	S83F	Silent mutations	None	Silent mutations
SE 051/04	>256	S83I	Silent mutations	None	Silent mutations
SE 052/04	>256	S83I	Silent mutations	None	Silent mutations
SE 099/06	>256	S83Y	Silent mutations	None	Silent mutations
STM 018/03	24	None	Silent mutations	None	M438I
STM 071/07	64	None	Silent mutations	None	None
STM 055/05	32	None	Silent mutations	None	None
STM 006/02	16	None	Silent mutations	None	None
STM 033/04	16	None	Silent mutations	None	None
STM 053/05	16	None	Silent mutations	None	None
STM 056/05	16	None	Silent mutations	None	None
STM 034/04	12	None	Silent mutations	None	None
STM 048/05	8	None	Silent mutations	None	None
STM 057/05	6	None	None	None	None

D, aspartic acid; F, phenylalanine; G, glycine; I, isoleucine; M, methionine; N, asparagine; S, serine; V, valine; Y, tyrosine; “silent mutations” denotes synonymous base substitutions in the QRDR of the target genes and thus does not result in amino acid change; “none” denotes wild-type sequence in the QRDR; that is, base substitution did not take place.
^aThe first letter indicates the original amino acid, followed by numbers that indicate the position of the amino acid in respective gene, and the last letter indicates the substituting amino acid. For example, D87Y means tyrosine replaced aspartic acid in position 87 in GyrA subunit.