Analysis of drug resistance of major pathogenic bacteria in porcine respiratory diseases to commonly used antibiotics

Liu Yu; Xie Yue; Liu Qihong; Guo Chunyan; Liao Hong; Yuan Fang; Yang Shanshan; Mao Li

doi:10.20154/j.cnki.issn1672-9692.2025.09.013

Abstract：This study aims to improve the prevention and control of porcine respiratory diseases,promote scientific and rational use of antibiotics,and provide references for reducing the irrational use of antibiotics and delaying the development of bacterial resistance.The drug susceptibility of 22 strains of Streptococcus suis,20 strains of Haemophilus parasuis,and 10 strains of Actinobacillus pleuropneumoniae to 12 commonly used antibiotics was analyzed.The results showed that except for amoxicillin/clavulanate potassium,the three pathogenic bacteria exhibited varying degrees of resistance to amoxicillin,ceftiofur,ampicillin,doxycycline,tiamulin,tilmicosin,enrofloxacin,florfenicol,colistin,lincomycin,and amikacin.Among them,the resistance rate to colistin exceeded 90%.Among the 22 strains of Streptococcus suis,six strains showed an inhibition zone diameter of amoxicillin/clavulanate potassium that was more than 5 mm larger than that of amoxicillin.Among the 20 strains of Haemophilus parasuis,12 strains showed an inhibition zone diameter of amoxicillin/clavulanate potassium that was more than 5 mm larger than that of amoxicillin.Among the 10 strains of Actinobacillus pleuropneumoniae,seven strains showed an inhibition zone diameter of amoxicillin/clavulanate potassium that was more than 3 mm larger than that of amoxicillin.The study indicates that all isolated pathogenic bacteria were sensitive to amoxicillin/clavulanate potassium,suggesting that amoxicillin/clavulanate potassium is the preferred drug for treating respiratory diseases caused by Streptococcus suis,Haemophilus parasuis,and Actinobacillus pleuropneumoniae.