Research Article

High Prevalence of Livestock-Associated Methicillin-Resistant Staphylococcus aureus in Hungarian Pig Farms and Genomic Evidence for the Spillover of the Pathogen to Humans

Table 1

Phenotypic antimicrobial susceptibility of 56 Swine-Related Livestock-Associated Methicillin-Resistant Staphylococcu saureus isolates.

Farm environment isolates (n=37)Swine professional isolates (n=19)Total (n=56)
R(%)I(%)S(%)R(%)I(%)S(%)R(%)I(%)S(%)

Penicillin37 (100)0 (0)19 (100)0 (0)56 (100)0 (0)
Cefoxitin36 (97.3)1 (2.7)17 (89.5)2 (10.5)53 (94.6)3 (5.4)
Tetracycline37 (100)0 (0)0 (0)19 (100)0 (0)0 (0)56 (100)0 (0)0 (0)
Clindamycin29 (78.4)0 (0)8 (21.6)18 (94.7)1 (5.3)0 (0)47 (83.9)1 (1.8)8 (14.3)
Trimethoprim21 (56.8)16 (43.2)11 (57.9)8 (42.1)32 (57.1)24 (42.9)
Quinupristin/dalfopristin20 (54.1)4 (10.8)13 (35.1)7 (36.8)8 (42.1)4 (21.1)27 (48.2)12 (21.4)17 (30.4)
Ciprofloxacin15 (40.5)3 (8.1)10 (52.6)5 (26.3)25 (44.6)8 (14.3)
Chloramphenicol17 (45.9)0 (0)20 (54.1)7 (36.8)0 (0)12 (63.2)24 (42.9)0 (0)32 (57.1)
Erythromycin15 (40.5)0 (0)22 (59.5)8 (42.1)0 (0)11 (57.9)23 (41.1)0 (0)33 (58.9)
Gentamicin4 (10.8)33 (89.2)3 (15.8)16 (84.2)7 (12.5)49 (87.5)
Fusidic acid1 (2.7)36 (97.3)0 (0)19 (100)1 (1.8)55 (98.2)
Linezolid1 (2.7)36 (97.3)0 (0)19 (100)1 (1.8)55 (98.2)
Rifampicin0 (0)0 (0)37 (100)0 (0)0 (0)19 (100)0 (0)0 (0)56 (100)
Vancomycin0 (0)37 (100)0 (0)19 (100)0 (0)56 (100)
Sulfamethoxazole0 (0)37 (100)0 (0)19 (100)0 (0)56 (100)

ECOFF (mg/L)NWT (%)WT (%)NWT (%)WT (%)NWT (%)WT (%)
Tiamulin§225 (67.6)12 (32.4)16 (84.2)3 (15.8)41 (73.2)15 (26.8)
Streptomycin§169 (24.3)28 (75.7)5 (26.3)14 (73.7)14 (25.0)42 (75.0)
Kanamycin§84 (10.8)33 (89.2)3 (15.8)16 (84.2)7 (12.5)49 (87.5)
Mupirocin§10 (0)37 (100)0 (0)19 (100)0 (0)56 (100)

R, resistant; I, susceptible, increased exposure; and S, susceptible. The susceptibility of 23 isolates could not be determined, because their minimal inhibitory concentration (MIC) fell below the lowest concentration measured (0.25 mg/L). MIC values evaluated according to the Clinical and Laboratory Standards Institute (CLSI) criteria. §Epidemiological cut-off (ECOFF) values were used to determine wild-type (WT) and non-wild-type isolates.