Previous antibiotic exposure and antibiotic resistance of commensal Staphylococcus aureus in Spanish primary care

Figures & data

Table 1. EUCAST definitions of clinical breakpoints issued by the 2017 European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the number of isolates studied.

	EUCAST breakpoints*		Resistance of the samples collected from the carriers
Antibiotic	S ≤ mg/L	R > Mg/L	S N (%)	R N (%)
Penicillin	0.125	0.125	99 (12.9)	666 (87.1)
Oxacillin	0.25	2	755 (98.7)	10 (1.3)
Erythromycin	1	2	679 (88.8)	86 (11.2)
Azithromycin	1	2	676 (88.4)	89 (11.6)
Clindamycin	0.25	0.5	691 (90.3)	74 (9.7)
Ciprofloxacin^1	1	1	747 (97.6)	18 (2.4)
Gentamicin	1	1	757 (99.0)	8 (1.0)
Tetracycline	1	2	751 (98.2)	14 (1.8)
Vancomycin	2	2	765 (100)	0 (-)
Linezolid	4	4	765 (100)	0 (-)
Daptomycin	1	1	765 (100)	0 (-)

S = susceptible; R = resistant.

* The figures correspond to the minimal inhibitory concentrations (MIC) in mg/L above, which germs are considered as resistant.

¹ Breakpoints are based on high dose therapy (750 mg ×2).

Table 2. Association of the previous number of antibiotics boxes dispensed and the staphylococcal resistance. A multivariate logistic regression analysis model.

Variable	95% CI	OR	P value
Staphylococcus aureus resistance
Age (years)	0.98–1.00	0.99	0.24
Sex (women)	0.45–1.14	0.72	0.16
Any antibiotics^a	0.99–1.16	1.07	0.55
Penicillin-resistant Staphylococcus aureus
Age (years)	0.99–1.01	1.00	0.76
Sex (women)	0.46–1.01	0.70	0.11
Penicillin packages (number)	1.04–1.35	1.18	0.01
Methicillin-resistant Staphylococcus aureus (MRSA)
Age (years)	0.99–1.05	1.02	0.22
Sex (women)	0.15–2.43	0.61	0.48
Any antibiotics^a	1.16–2.20	1.60	<0.01

^aHave taken one or more antibiotic boxes.