Whole genome analysis of linezolid resistance in Streptococcus pneumoniae reveals resistance and compensatory mutations

Table 4 Functional analysis of mutations in genes spr0188, spr0196, spr0333, spr1021 and spr1887 in resistance to LNZ and other antibiotics in S. pneumoniae.

Strains/transformants^a	Locus^b	No. of colonies tested	Mutation status 1974M1^c,d	Mutation status Transformants^c,d	MIC LNZ^e (μg/ml)	MIC CHL^e (μg/ml)	MIC FFC^e (μg/ml)
R6					0.5	3	2
T-R6^spr0188	spr0188	8	A409G Y137H	A409G Y137H	0.5	3	3
T-R6^spr0196	spr0196	8	T235G I79L	T235G I79L	0.5	3	2
T-R6^spr1887	spr1887	8	G-46T	G-46T	0.5	3	2
1974					1	3	2
T-1974^spr0333	spr0333	8	G626T G209V	G626T G209V	1	4	4
T-1974^spr1021	spr1021	3	G-29T	G-29T	2	4	4
T-1974^{23SrDNA1974M1} (T-7)	spr_rrnaDCBA23S		G2576T	G2576T	16	24	16
T-7^spr0333	spr0333	4	G626T G209V	G626T G209V	16	24	16
T-7^spr1021	spr1021	2	G-29T	G-29T	32	32	32
T-7^spr1887	spr1887	4	G-46T	G-46T	16	24	16
T-7^sp0188	spr0188	4	A409G Y137H	A409G Y137H	16	24	16
T-7^{sp0188, spr0196}	spr0188		A409G Y137H	A409G Y137H	32	12	8
	spr0196		T235G I79L	T235G I79L

^a T stands for transformants; spr0188 (ribosomal protein L3); spr0196 (ribosomal protein L16); spr0333 (conserved hypothetical protein/rRNA methyltransferase) spr1021 (ABC protein-coding gene); spr1887 (patA ABC gene).
^b The S. pneumoniae loci number (spr#) are according to the nomenclature of S. pneumoniae R6.
^c In noncoding sequences, the number preceded by '-' indicates the position upstream of the ATG.
^d When the mutations are within coding regions, the changes in amino acids is indicated in italics.
^e LNZ (linezolid); CHL (chloramphenicol); FFC (florfenicol).

ISSN: 1471-2164