Abstract: This experiment was conducted to investigate the bacterial causes and drug resistance of pig arthritis of four farms in Yunnan.Through isolation and culture,biochemical test,drug sensitive test,animal pathogenicity experiment and 16S rRNA identification,we analyzed the samples from four farms with pig arthritis symptom.The results showed that in all 96 samples,55 samples were Staphylococcus aureus positive,the positive rates were 20.8%,83.3%,91.7% and 33.3% in A,B,C and D farms,respectively;56 samples were Streptococci positive,the positive rates were 95.8%,21.7%,25.0% and 83.3%,respectively;Mixed infection rates were 20.8%,21.7%,25.0% and 33.3%,respectively.Therefore,Staphylococcus aureus was the major bacterial pathogen which caused pig arthritis in B and C farms;Streptococci was the major bacterial pathogen which caused pig arthritis in A and D farms;Two kinds of bacteria were more sensitive to ceftriaxone,minocycline and ciprofloxacin,and resistant to multiple antibiotics.

Key words: pig arthritis; Staphylococcus aureus; Streptococci; 16S rRNA identification