猪源致病性金黄色葡萄球菌的分离鉴定及其耐药性分析

目的鉴定引起猪渗出性皮炎的病原,并分析猪源致病性金黄色葡萄球菌的耐药性,为临床用药提供依据。方法采集患渗出性皮炎的仔猪标本进行细菌分离培养,联合应用形态学检查、生理生化试验和PCR方法鉴定分离菌株,并进行致病性和药物敏感性试验。结果先后从病猪标本中分离鉴定获得PSA1、PSA2、PSA3和PSA4四株金黄色葡萄球菌,其中PSA1和PSA3分离株的致病性较强。药敏试验结果显示PSA1、PSA2和PSA3分离株为MRSA菌株,PSA4分离株为MSSA菌株。MRSA菌株对14种抗菌药物均呈现不同程度的耐药,尤其是对青霉素、链霉素、四环素、强力霉素、环丙沙星和氧氟沙星等6种抗菌药物的耐药率达100%。所有分离株对万古霉素与替考拉宁均敏感。结论合肥地区猪渗出性表皮炎的病原为金黄色葡萄球菌。猪源致病性金黄色葡萄球菌合肥分离株具有多重耐药性,治疗猪渗出性皮炎应建立在体外药敏试验的基础上,有针对性选择抗菌药物。

Isolation,identification and drug resistance analysis of pathogenic Staphylococcus aureus from the samples of exudative dermatitis piglets

Objective To identify the pathogen causing exudative dermatitis of piglets,and analyze the drug resistance of pathogenic Staphylococcus aureus（S.aureus）isolates for the future guiding of clinical treatment. Method The pathogen was isolated from the samples of exudative dermatitis piglets and identified by morphology inspection,cultural properties,biochemical reactions and PCR method. In addition,pathogenicity and the drug resistance of the pathogens isolated was determined by animal experiment and drug sensitivity test. Result Four strains of S.aureus named PSA1,PSA2,PSA3 and PSA4 were isolated and identified from samples of sick piglets successively. As demonstrated by animal experiment,the strain PSA1 and PSA3 showed stronger pathogenicity to experimental animals. The results of drug sensitivity test showed that PSA1,PSA2 and PSA3 strains were Methicillin resistant Staphylococcus aureus （MRSA） ,while PSA4 was Methicillin sensitive Staphylococcus aureus （MSSA）. The isolates of MRSA showed resisitance to 14 kinds of antibiotic drugs at different extents. Especially,the resistant rates to penicillin,streptomycin,tetracycline,doxycycline,ciprofloxacin and levofloxacin were all 100%. All isolated strains were sensitive to vancomycin and teicoplanin.Conclusion The pathogen causing exudative dermatitis of piglets in Hefei area is S.aureus that showed multi-drug resistance. The sensitive drug selected by drug sensitivity test in vitro may be used for clinical treatment of exudative dermatitis.