Abstract: This study was conducted to investigate the resistance to common antibiotics and genes of Haemophi- lus parasuis isolated from the scaled pig farms in Zhejiang province．A total of 73 Zhejiang H．parasuis isolates were tested for their resistance to 18 antibiotics by K- B method．PCR was used to detect related genes．The amplified products were sequenced and aligned．The results showed that 86．30% isolates were resistant to sulfonamides， 65.75%，60．27%，50．68%，50．68% and 46．58% isolates were resistant to tetracyclines，aminoglycosides，quino- lones，- lactam antibiotics，chloramphenicols，respectively，while only 28．77% isolates were resistant to macrolides． Resistance genes were detected in 97．26% isolates，and multiple resistance genes were found in 84．93% isolates． The rates of resistance genes Aac(6')－ 1b，AadA1，Sul1，Sul2，Flor，CmLA，Cat1，TetA，TetB，Tem- 11 and ErmB were 76．71%，65．75%，45．2%，10．96%，15．07%，8．22%，58．9%，4．11%，49．32%，35．62% and 1．37%，respec- tively．The coincidence of phenotype and genotype for the isolates to resist sulfonamides，- lactam antibiotics，chlor- amphenicols，tetracyclines，macrolides，quinolones and aminoglycoside antibiotics were 62．07%，74．29%， 81. 48%，75．00%，0，75．68% and 72．09%，respectively．Therefore，H．parasuis has developed resistance to clini- cally commonly used antibiotics and the results from analysis of drug- resistant gene could be used as reference to determine resistance bacteria．

Key words: Haemophilus parasuis, Drug resistance, Drug- resistant gene

CLC Number: 

• S432.4