Genetic resistance determinants to fusidic acid and chlorhexidine in variably susceptible staphylococci from dogs

BMC Microbiology

Table 1 Minimum inhibitory concentrations (MICs) of fusidic acid determined by agar dilution, and presence of resistance determinants, for canine-derived Staphylococcus pseudintermedius and S. aureus isolates (n = 578) from Finland, the U.S.A., North U.K. (NUK), South-East U.K. (SEUK) and Germany

Country	Bacterial Type	n	Fusidic acid MIC (mg/L)														MIC₅₀	MIC₉₀
Country	Bacterial Type	n	≤0.015	0.03	0.06	0.125	0.25	0.5	1	2	4	8	16	32	64	>64	(mg/L)	(mg/L)
Finland	MRSP	49	0	0	28 n = 2 fusC	0	0	0	0	3	5 n = 4 fusC	4 n = 2 fusC	8 n = 1 fusC	0	1 n = 1 fusA	0	0.06	16
	FA-R MRSP	40	0	0	0	0	0	0	0	0	13 n = 12 fusC	10 n = 1 fusC n = 2 fusB	5	0	12 n = 12 fusA	0	8	64
	MSSP	50	0	1	38 n = 1 fusC	1	0	0	0	0	0	7 n = 3 fusC	3 n = 1 fusC	0	0	0	0.06	8
U.S.A.	MRSP	50	0	2	38	10	0	0	0	0	0	0	0	0	0	0	0.06	0.125
U.S.A.	MSSP	51	0	0	47	2	0	0	0	0	2	0	0	0	0	0	0.06	0.06
NUK	MRSP	49	0	0	14 n = 1 fusC	4	0	0	0	14	2 n = 1 fusC	10 n = 5 fusC	0	0	4 n = 4 fusA	1	2	64
NUK	MSSP	50	0	1	37	0	0	0	1	0	1	5	1	0	2 n = 2 fusA	2 n = 2 fusA	0.06	8
SEUK^a	MRSP	47	22	1	12	3	0	0	1	2	4	0	1	0	1 n = 1 fusA	0	0.06	4
	MSSP	44	19	5	14	1	0	0	2	2	0	1	0	0	0	0	0.03	1
	MRSA	50	8	34	0	0	3	0	0	0	0	0	0	0	1	4 n = 2 fusA	0.03	0.25
	MSSA	50	24	13	0	0	1	1	6	2	2 n = 2 fusC	0	1	0	0	0	0.03	1
Germany^a	MRSP	24	0	0	0	0	0	0	0	0	0	0	0	0	0	0	<0.015	<0.015
Germany^a	MSSP	21	0	0	0	0	0	0	0	3	0	0	0	0	0	0	<0.015	<0.015

EUCAST breakpoint for fusidic acid for staphylococci is 1 mg/L; (reference [62]).
MRSP methicillin-resistant Staphylococcus pseudintermedius, FA-R fusidic acid-resistant, MSSP methicillin-sensitive S. pseudintermedius, NUK North U.K., SEUK South-East U.K, MRSA methicillin-resistant S. aureus, MSSA methicillin-susceptible S. aureus.
^aMICs determined as part of previous study by the authors (reference [52])

ISSN: 1471-2180