The increase of methicillin-resistant Staphylococcus aureus(MRSA) and the presence of an unusual sequence type ST49 in slaughter pigs in Switzerland

Table 2 The clonal lineage and resistance profile of methicillin-resistant Staphylococcus aureus from pig noses in Switzerland.

						Antibiotic resistance genes and resistance breakpoints (mg/L)^b
MLST	*spa*type	SCCmectype	Number of isolates	Farm^a	Representative strain	FOX	PEN	TET	ERY	CLI	STR	TIA	SPC	TMP	SMX	CIP
						(>4)	(>0.125)	(>2)	(>2)	(>0.5)	(>16)	(>2)	(>128)	(>2)	(>128)	(>1)
2009
ST1	t2279	IVc	1	TG3	IMD887-09	mecA	mecA blaZ	tet(M)	erm(A)	erm(A)			ant(9)-Ia			+
ST398	t011	V	1	SG1	IMD358-09	mecA	mecA	tet(M) tet(K)				vga(A)v
ST398	t011	V	1	TG1	IMD355-09	mecA	mecA	tet(M) tet(K)	erm(C)	erm(C)			+
ST398	t011	V	1	LU2	IMD1753-09	mecA	mecA	tet(M) tet(K)					+
ST398	t034	V	1	BE1	IMD1116-09	mecA	mecA blaZ	tet(M) tet(K)	erm(A)	erm(A)	str	+	ant(9)-Ia	dfr(G)
ST398	t1451	V	1	LU1	IMD1270-09	mecA	mecA	tet(M) tet(K)	erm(C)	erm(C)	str	vga(A)v
ST49	t208	V	1	TG2	IMD1000-09	mecA	mecA	tet(M) tet(K)	erm(C)	erm(C)		vga(A)v			+
ST49	t208	V	1	SG2	IMD1771-09	mecA	mecA	tet(M) tet(K)				vga(A)v			+
2010
ST398	t034	V	16	TG5 TG8 TG9 TG10 LU3 LU4 LU5 LU6 BE2 BE3 BE4 AG1 JU1 SG3 SG5 ZH1	IMD49-10	mecA	mecA blaZ	tet(M) tet(K)	erm(A)	erm(A)	str	+	ant(9)-Ia	dfr(G)
ST398	t034	V	1	TG 7	IMD704-10	mecA	mecA blaZ	tet(M) tet(K)	erm(A)	erm(A)		+	ant(9)-Ia	dfr(G)
ST398	t011	V	1	AI1	IMD233-10	mecA	mecA	tet(M) tet(K)	erm(C)	erm(C)			+
ST49	t208	V	3	SG4 SG6 TG4	IMD426-10	mecA	mecA	tet(M) tet(K)				vga(A)v			+
ST49	t208	V	1	TG6	IMD603-10	mecA	mecA	tet(M) tet(K)	erm(A)	erm(A)		vga(A)v			+
ST49	t208	V	1	AG2	IMD2002-10	mecA	mecA	tet(M) tet(K)			str	vga(A)v			+

a) Geographical origin of the farm: letters indicate the Cantons (AI, Appenzell Innen Rhodes; AG, Aargau; BE, Bern; JU, Jura; LU, Luzern; SG, St Gallen; TG, Thurgau; ZH, Zurich). and numbers indicate individual farms.
b) CIP, ciprofloxacin; CLI, clindamycin; ERY, erythromycin; FOX, cefoxitin; PEN, penicillin; SPC, spectinomycin; SMX, sulphamethoxazole; STR, streptomycin; TET, tetracycline; TIA, tiamulin; TMP, trimethoprim. The MIC breakpoints (in micrograms per millilitre) that determine resistance were recommended from EUCAST for S. aureus http://www.eucast.org. Resistance breakpoints for tiamulin, spectinomycin, streptomycin and sulphamethoxazole were tentatively derived from epidemiological MIC cut-off values from EUCAST.
Antibiotic resistance genes and their functions are indicated as follows: ant(9)-Ia, spectinomycin adenylnucleotidyltransferase; blaZ, β-lactamase; dfr(G), dihydrofolate reductase; erm(A) and erm(C), macrolides, lincosamides and streptogramins B rRNA methylase; mecA, penicillin-binding protein PBP2a; str, streptomycin adenyltransferase; tet(K), tetracycline efflux protein; tet(M), tetracycline ribosomal protection protein; vga(A)v, pleuromutilins and streptogramins A ATP binding transporter.
ND, not detected; +, The MIC values were greater than the resistance breakpoint, but the resistance mechanism remained uncharacterised; blank spaces indicate no resistance

ISSN: 1746-6148