猪源肠球菌的分离鉴定及其部分特性研究

发布时间：2018-11-24 12:58

【摘要】：为了解猪源肠球菌分离株的耐药特点及其毒力基因分布特征,为肠球菌感染疾病的治疗防控提供依据,此次研究从湖南省部分猪场的健康猪肠道内及患有流行性腹泻的病猪肠道内分离肠球菌,并对分离菌株进行耐药性及毒力基因检测。1.本实验一共分离肠球菌115株,其中粪肠球菌11株,屎肠球菌59株,其他肠球菌45株。有72株肠球菌(包含30株屎肠球菌,2株粪肠球菌,40株其他肠球菌)分离自四个猪场的健康猪群肠道内；另外43株肠球菌分离自流行性腹泻病猪肠道内,包括29株屎肠球菌,9株粪肠球菌,5株其他肠球菌。2.使用K-B法检测1 15株肠球菌的耐药表型并通过PCR方法检测其耐药基因。结果显示：健康猪源肠球菌对高浓度庆大霉素最敏感为93.06%,其次为替考拉宁和氯霉素,敏感率分别为81.94%和65.28%。流行性腹泻病猪中分离肠球菌对四环素、红霉素、头孢噻吩这三种抗生素完全不敏感,除糖肽类抗生素和氨苄西林外,对其它几种药物的敏感率均低于健康猪源肠球菌的敏感率。分离的1 1 5株肠球菌多重耐药现象严重,有98.3%的肠球菌对14种抗生素呈三重或三重以上的耐药,比较分析湖南健康猪源与PEDV猪源肠球菌的多重耐药情况,发现PEDV猪源肠球菌比健康猪源的肠球菌呈更多重耐药的菌株数比健康猪源的肠球菌多。所有的粪肠球菌为六重及六重以上的耐药,多重耐药最为严重。本次对肠球菌的耐药性进行检测发现,猪源肠球菌已对多种抗生素耐药,尤其是对四环素和红霉素,几乎是全部耐药。各耐药基因的检出率分别为tetM (69.6%)、 Aac(6)'/aph(2") (62.6%)、aph(3)'-Ⅲ (70.4%)、ant(6)'-Ⅰ (60%)、ermB (58.2%)、 mefA (0.9%)、 VanB (0.9%), VanA和VanC基因未检测到。通过耐药基因型与耐药表型比较分析,发现肠球菌耐药表型与耐药基因并不完全一致。3.采用PCR方法对分离的115株肠球菌的毒力基因进行检测,总共检出9种毒力基因,分别是cylA、ace、esp、hy1、asal、efaA、gelE、EF0591、EF3314。研究结果表明健康猪肠道内分离的72株肠球菌也含有毒力因子,但其存在量较低,各基因的检出率低于16%。四个猪场毒力基因的检出率有较大差异,猪场C的毒力基因检测率最高,猪场B未检测到带有毒力基因的菌株,这可能与养殖场的饲养管理相关或肠球菌的毒力基因在地域与地域之间存在差异。通过健康猪源肠球菌与流行性腹泻病猪分离肠球菌之间毒力基因检测结果的比较分析,发现从流行性腹泻病猪分离的肠球菌检测到的毒力基因菌株数要多。不同肠球菌携带耐药基因的比较中,粪肠球菌毒力基因的携带量要多于其他肠球菌。
[Abstract]:In order to understand the characteristics of drug resistance and the distribution of virulence genes of Enterococcus enterococci isolated strains from pigs, and to provide the basis for the treatment and control of enterococcal infection, In this study, Enterococcus was isolated from the intestinal tract of healthy pigs in some pig farms in Hunan Province and from the intestinal tract of diseased pigs suffering from epidemic diarrhea, and the drug resistance and virulence genes of the isolated strains were detected. 1. A total of 115 strains of Enterococcus faecalis, 59 strains of Enterococcus faecium and 45 strains of other Enterococcus were isolated. 72 strains of Enterococcus (including 30 Enterococcus faecium, 2 Enterococcus faecalis and 40 other Enterococcus faecalis) were isolated from the intestinal tract of healthy pigs in four pig farms. Another 43 strains of Enterococcus were isolated from the intestinal tract of epidemic diarrhea pigs, including 29 strains of Enterococcus faecium, 9 strains of Enterococcus faecalis and 5 strains of other enterococci. The resistance phenotypes of 115 strains of Enterococcus were detected by K-B method and their resistant genes were detected by PCR method. The results showed that the highest sensitivity of Enterococcus from healthy pigs to high concentration of gentamicin was 93.06, followed by teicoplanin and chloramphenicol, and the sensitivity rates were 81.94% and 65.2828%, respectively. Enterococcus isolated from epidemic diarrhea pigs was completely insensitive to tetracycline, erythromycin and cefthiophene, except for glycopeptide antibiotics and ampicillin. The sensitivity to other drugs was lower than that of healthy enterococcus. One hundred and fifteen strains of Enterococcus were found to be resistant to three or more antibiotics, 98.3% of which showed triple or more resistance to 14 antibiotics. The multidrug resistance of Hunan healthy swine and PEDV porcine enterococcus was compared and analyzed. It was found that more strains of enterococcus from PEDV were more resistant than those from healthy pigs. All Enterococcus faecalis are six or more resistant, multi-resistant is the most serious. It was found that Enterococcus suis was resistant to many antibiotics, especially tetracycline and erythromycin. The detectable rate of resistant genes was tetM (69.6%), Aac (6'/ aph (2 ") (62.6%), aph (3)'- 鈪，

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