为研究猪流行性腹泻(PED)病猪群中肠球菌及其携带毒力基因的变化情况,本研究采用PCR方法对115株猪源肠球菌检测其11种毒力基因的分布情况及进行了其溶血试验和明胶液化试验.结果,共检测到9种毒力基因:EF3314、efaA、gelE、ace、asal、cylA、esp、Hyl和EF0591,其中asa373和AS未检测到.72株健康猪源分离菌中毒力基因检出率分别为12.5％、9.7％、5.6％、2.8％、13.9％、4.2％、8.3％、15.3％和1.4％.43株PED病猪分离菌毒力基因阳性率分别为20.9％、25.6％、2.3％、18.6％、51.2％、11.6％、20.9％、0和7.0％.溶血试验结果显示115株肠球菌中溶血的占88.7％,其中α-溶血占40％,β-溶血占48.7％,共有8株检测到溶血素A基因(clyA),检出率为6.9％.11株粪肠球菌全部表现溶血,其中健康猪源分离株为α-溶血,PEDV感染猪分离株为β-溶血.明胶液化试验表明115株肠球菌中只有两株能液化明胶,均为粪肠球菌,一株为健康猪源分离株,一株为PEDV感染猪分离株,而且从这两株菌中均检测到了明胶酶E(gelE)基因.表明PED猪源肠球菌毒力基因检出率明显高于健康猪源肠球菌(p＜0.05).明胶液化试验和溶血试验结果表明,粪肠球菌的这两种表型与基因型为肠球菌种中表达一致性是最高的,其携带毒力基因为肠球菌中所占比例最高.通过两种不同来源肠球菌毒力基因的比较,为PED的分析治疗与防控提供依据.%To explore the differences of Enterococcus isolates and its virulence genes between health and porcine epidemic diarrhea virus (PEDV) infected pigs,the distribution of 11 main virulence genes were detected in 115 Enterococcus isolates from pigs by PCR,and further tested by hemolysis and gelatin dissolution test.The results shown that 9 types of virulence genes were detected including EF3314,efaA,gclE,ace,asal,cylA,esp,hyl and EF0591 (but not As and asa373),of which were 12.5％,9.7％,5.6％,2.8％,13.9％,4.2％,8.3％,15.3％ and 1.4％ among the 72 isolates from the healthy pigs respectively,but they were 20.9％,25.6％,2.3％,18.6％,51.2％,11.6％,20.9％,0 and 7.0％ in 43 isolates from PEDV infected pigs,respectively.In addition,88.7％ (102/115) isolates of the Enterococcus induced hemolysis on Colombia blood agar plate with o-hemolysis for 40％ and β-hemolysis for 48.7％,but the hemolysin A gene (clyA) was only detected in 8 Enterococcus.While,the total of 11 of E.faecalis from the hemolytic Enterococcus were further identified that α-hemolysis or β-hemolysis was only detected in the isolates from healthy or PEDV infected swine,respectively.Only 2 of 115 isolates were able to dissolute gelatin and they were both E.faecalis with gelE gene.In conclusions,the rate of virulence gene in isolates from PEDV infected swine was much higher than that from healthy swine (p＜0.05).The hemolysis and gelatin dissolution tests suggested that the phenotype and genotype of E.faecalis were possessed the highest consistency in gene expression in Enterococcus.Meanwhile,E.faecalis has the highest carrying rate of virulence gene in Enterococcus species.These data provide a basis for the study of the disease prevention and control.
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