Sub-inhibitory concentrations of oxacillin modify the expression of agr locus in Staphylococcus aureus clinical strains belonging to different clonal complexes

Table 3 Expression levels changes in RNAIII and agrA locus under exposure to oxacillin subMICs in the stationary growth phase clustered by methicillin resistance; Clonal Complex and agr type

	RNAIII			agrA
	subMIC OXA ^a vs. No subMIC OXA Fold_Change		P ^b;c	subMIC OXA vs. No subMIC OXA Fold_Change		P
Methicillin resistance
MRSA	2.26	POS	0.051	1.80	POS	0.163
MSSA	1.75	POS	0.149	1.82	POS	0.003
Clonal complex
CC45	1.74	POS	0.005	1.61	POS	0.000
CC8	1.07	NEG	1.000	1.81	POS	0.022
CC5	2.36	POS	0.108	3.61	POS	0.008
CC15	3.48	POS	0.005	4.48	POS	0.001
CC30	7.16	NEG	0.071	1.32	NEG	0.138
agr type
agrI	1.10	POS	0.804	1.62	POS	0.001
agrII	3.95	POS	0.001	3.98	POS	0.000
agrIII	7.16	NEG	0.071	1.32	NEG	0.138

^a OXA: Oxacillin
^b POS: fold change positive in the expression level under exposure to oxacillin subMIC. NEG: fold change negative in the expression level under exposure to oxacillin subMICs
^c Bold numbers indicate statistical significant results (P < 0.05)

ISSN: 1471-2334