Regulation of virulence and β-lactamase gene expression in Staphylococcus aureus isolates: cooperation of two-component systems in bloodstream superbugs

Table 1 Frequency of antibiotic resistance, virulence factors, and SCCmec types, in BSI collection of MRSA and MSSA strains

Antimicrobial agent	MRSA (n = 61)			P ^#	MSSA (n = 30)			P ^#
Antimicrobial agent	R	I	S	P ^#	R	I	S
Cefoxitin	61	0	0	0.004	0	0	30	0.025
Gentamycin	38	8	16	0.03	1	0	29	0.012
Erythromycin	19	16	6	0.03	0	0	30	0.025
Amikacin	11	18	32	0.12	0	0	30	0.025
Ciprofloxacin	33	12	16	0.021	0	0	30	0.025
Clindamycin	19	13	29	0.022	0	0	30	0.025
Chloramphenicol	8	16	37	0.65	7	0	23	0.65
Linezolid	8	19	34	0.040	0	0	30	0.025
Daptomycin	11	0	50	0.79	0	0	30	0.025
Penicillin	61	0	0	0.001	13	9	8	0.059
Gatifloxacin	40	11	12	0.025	9	1	20	0.025
Trimethoprim/sulfamethoxazole	11	0	50	0.82	0	0	30	0.025
MDR	56			0.051	4			0.95
XDR	24			0.072	0			–
PDR	8			0.22	0			–
SCCmec types
SCCmecI	10			0.019	0			–
SCCmecII	14			0.041	0			–
SCCmecIII	24			0.020	0			–
SCCmecIV	13			0.008	0			–
SCCmecV	10			0.045	0			–
Virulence factor genes
tst	19			0.021	0			–
etA	11			0.001	0			–
etB	5			0.071	0			–
lukS-PVL	19			0.035	0			–
lukF-PV	11			0.040	0			–
lukE-lukD	10			0.055	0			–
edinA	2			0.037	0			–
hla	10			0.111	0			–
hlb	13			0.018	0			–
hld	9			0.068	0			–
hlg	14			0.018	0			–

S Susceptible, R Resistant, I Intermediate; ^#Statistical relationship between chi-square test between different variables with significant level ≤ 0.05

ISSN: 1471-2180