摘要
为了鉴定青岛地区3个猪场病死猪的致病菌,试验采用形态学观察、生化试验、16S rRNA PCR鉴定、血清型鉴定、毒力因子基因表型检测及药敏试验等方法对分离得到的3株细菌进行研究。结果表明:这3株细菌均为革兰氏阳性链状球菌,生化特性与猪链球菌的生化特征大致相符;16S rRNA PCR产物测序结果证实3株细菌均为猪链球菌;用猪链球菌1,2,7,9型特异性引物进行PCR扩增,3株细菌均为猪2型链球菌,其中有2株细菌的毒力因子基因表型为Mrp+Epf+Sly+,1株细菌毒力因子基因表型为Mrp-Epf+Sly+;3株细菌对大部分β内酰胺类、氟喹诺酮类抗生素敏感,对多肽类、林可胺类抗生素耐药。说明猪场分离得到的3株细菌均为2型猪链球菌,可选用β内酰胺类、氟喹诺酮类抗生素进行治疗。
To identify the pathogenic bacteria of dead pigs in three pig farms of Qingdao, further to control the swine streptococcal disease, the three strains were identified by morphological observation, biochemical experiments, 16 S rRNA PCR identification, serological identification, virulence gene testing and drug susceptibility testing. The results showed that these three strains were gram-positive streptococcus, and its biochemical characteristics were roughly in line with Streptococcus suis.The results of the sequencing of 16 S rRNA PCR products were confirmed by blast comparison, which showed that these three strains were Streptococcus suis.The PCR amplification with 1, 2, 7, 9 primers of Streptococcus suis shoued that all of which were Streptococcus suis type 2. The virulence factor gene phenotypes of L1 and L2 strains are Mrp+Epf+Sly+, and the virulence factor gene phenotype of L3 strain is Mrp-Epf+Sly+. The results of drug susceptibility test showed that these three strains were highly sensitive to β-lactam, fluoroquinolones, but resistant to peptides Class, Lin amine drugs. According to the results, it is reasonable to say that all of these three strains isolated from the pig farms are Streptococcus suis and it can be treated by β-lactam and fluoroquinolones.
引文
[1] 程尧, 李助南, 郭咪咪,等. 猪链球菌的分离鉴定及药敏试验[J]. 黑龙江畜牧兽医, 2016(08上):161-164.
[2] 许大文,魏建忠,孙裴,等.猪链球菌2型安徽分离株毒力基因cps2J、mrp、epf、sly的检测及其序列分析[J].动物医学进展,2012, 33(12):12-16.
[3] HERNANDEZ-GARCIA J,WANG J,RESTIF O,et al.Patterns of antimicrobial resistance in Streptococcus suis isolates from pigs with or without streptococcal disease in England between 2009 and 2014[J].Vet Microbiol,2017,207:117-124.
[4] CALLENS B F, HAESEBROUCK F, MAES D, et al. Clinical resistance and decreased susceptibility in Streptococcus suis isolates from clinically healthy fattening pigs[J]. Microb Drug Resist, 2013, 19(2):146-151.
[5] VAN HOUT J,HEUVELINK A,GONGGRIJP M.Monitoring of antimicrobial susceptibility of Streptococcus suis in the Netherlands, 2013-2015[J]. Vet Microbiol,2016,194:5-10.
[6] 宋子杰,孙鑫鹏,王妍,等.猪链球菌的分离鉴定及药敏试验[J].山东畜牧兽医,2017,38(2):1-2.
[7] 李明,何孔旺,陆承平.猪链球菌2型MRP与EPF基因串联表达蛋白及其免疫保护作用[J].中国农业科学,2005,38(6):1264-1269.
[8] 祝令伟,纪雪,李丽红,等.屠宰场猪链球菌分离菌株分型及其致病性和耐药性分析[J].中国兽医学报,2017,37(2):272-277.
[9] 许大文. 致病性猪链球菌安徽分离株的生物学特性研究[D].合肥:安徽农业大学,2012.
[10] 孔宪刚,王笑梅.兽医微生物学[M].2版.北京:中国农业出版社,2013.
[11] 黎敏.2型猪链球菌分离鉴定及毒力基因检测[J].广东畜牧兽医科技,2016,41(3):18-20.