A diverse collection of 261 Staphylococcus aureus strains from human, animal, 
food, and environmental sources were tested for the presence and type of SCCmec 
elements, antibiotic susceptibility to various antibiotics, and non-ß-lactam 
antibiotic resistance genes. About 18.39% (48/261) of strains were 
methicillin-resistant S. aureus (MRSA) including 29.75% (36/121) human strains 
of which 29 strains were hospital-acquired MRSA (HA-MRSA) and 7 strains were 
community-associated MRSA (CA-MRSA) and 19.67% (12/61) animal strains that all 
were CA-MRSA strains. The percentage of CA-MRSA strains from animals was 
significantly higher than that from human (p<0.01). Most of MRSA strains and a 
part of methicillin-susceptible S. aureus (MSSA) strains harbored unique 
combinations of non-ß-lactamase genes aac(6')/aph(2″), aph(3')-III, ant (4',4″), 
ermA, ermC, mrsA, tetM, and tetK. Antibiotic resistance genes were detected more 
frequently in HA-MRSA strains than in CA-MRSA strains (p<0.01). MRSA strains and 
MSSA strains had 22 and 39 antibiotic profiles to 15 tested antibiotics, 
respectively. The resistant proportion was higher in HA-MRSA strains than in 
CA-MSSA strains for various antibiotics, as well as higher in MRSA strains than 
in MSSA strains. Animal MRSA reservoirs (particularly pigs and cows) might 
represent an important source of human CA-MRSA. CA-MRSA strains might acquire 
more different resistance genes gradually, depending on the selective pressure 
of antibiotics in different regions or environments. CA-MRSA is not yet endemic 
in China, but could be prevalent in future, contributing to its acquiring more 
resistance genes and huge animal sources. Infection with multidrug-resistant 
MSSA strains acquired from food, animal, and human sources might also become a 
significant problem for human medicine, which warrants further study.