Table 1.

Dominant serine/double-serine mutations in “fluoroquinolone-associated” STs/lineages of multi-drug resistant pathogens (see references in text).

Pathogen	ST/lineage*	GyrA	ParC/GrlA
MRSA	ST5, 8, 22, 239	Ser84Leu	Ser80Phe
K. pneumoniae	ST11, 15, 147, 258	Ser83Phe, Ser83Ile	Ser80Ile
E. coli	ST131 H30	Ser83Ile	Ser80Ile
C. difficile	ribotype 1, 2, 5, 14, 15, 20, 23, 27	Thr82Ile	**
S. pneumoniae	ST63, 81, 83, 156, 180, 191, 236, 260,11892	Ser81Phe, Ser81Tyr	Ser79Phe, Ser79Tyr
E. faecium	lineages related to CC17	Ser83Tyr, Ser83Arg	Ser80Ile, Ser80Arg ***
P. aeruginosa	to be established	Thr83Ile	Ser87Leu ***

^*The lists, with the exception of E. coli, are not complete.

^**The species does not carry the parC gene.

^***Some of the strains are void of parC mutations.