山东省猪源肠球菌酰胺醇类药物耐药表型及耐药机制研究

目的调查山东省猪源肠球菌的分离情况，对酰胺醇类药物敏感性及相关耐药机制，探究引起肠球菌酰胺醇类耐药的可能机制。方法应用肠球菌选择培养基进行肠球菌分离，16SrDNA序列扩增进行肠球菌种属鉴定，从采集自山东省44份猪粪便样本中分离得到肠球菌，应用微量肉汤稀释对其进行酰胺醇类药物耐药性研究，并利用普通PCR方法对常见的9种可水平移动的酰胺醇类耐药基因进行检测。结果共分离得到34株肠球菌（分离率77．3％），发现分别有21株（61．8％）和25株（73．5％）的分离株对氯霉素和氟苯尼考耐药。耐药菌株中存在可水平传播的酰胺醇类耐药基因catA7（11株），catA8（2株），fexA（7株），fexB（5株），cfr（3株）。7株肠球菌同时存在两种不同的酰胺醇类耐药基因。结论本研究中猪源肠球菌分离率较高，对酰胺醇类药物有很高的耐药性，分离株中存在的可水平移动的酰胺醇类耐药基因可能参与了受试菌株对酰胺醇类药物的耐药性。提示应加强畜牧兽医临床酰胺醇类耐药肠球菌的监测、检测工作，为了解我国动物源肠球菌耐药性现状，防控耐药肠球菌的传播和流行提供基础数据。

Characterization phenotypes and mechanisms of phenicols resistance among Enterococcus species of swine origin from Shandong Province

To investigate the prevalence, phenicols resistance and mechanisms of Enterococcus spp. isolates, 44 swine feces samples were collected. Totally 34 isolates （77. 3 %） were isolated and identified by enterococci selective agar and 16S rDNA sequence analysis. Antimicrobial agents sensitivity test showed that 61.8% （n=21） and 73.5 % （n=25） of the Enterococcus spp. isolates were resistant to chloramphenicol and florfenicol, respectively. Horizontal transfer resistance genes catA7, catAS, fexA, fexB, and cfr were detected in 11, 2, 7, 5, and 3 Enterococcus spp. isolates, respectively. Seven iso- lates harboured two kinds of phenicol resistance genes, simultaneously. The observation in this study suggested that high phen- icols resistance rate in swine Enterococcus spp. isolates. More attention should be given on investigation and research of animals phenicols resistance enterococci.