摘要
为了解猪2型链球菌的致病性强弱、生长繁殖特性及耐药性变化,试验通过细菌分离鉴定、生化试验、生长曲线、OD600值与其活菌数相关性曲线、药敏试验、小鼠致病性试验、病理组织学观察等方法对分离得到的猪2型链球菌进行研究。结果表明:病猪体内分离得到的链球菌经鉴定为猪2型链球菌,将其命名为TA01株;TA01株在6~8 h繁殖达到最高峰,8 h后活菌数逐渐下降;活菌数和OD600值的相关性方程为y=24.659x-1.076 1,R2=0.996 7;TA01株对青霉素、红霉素、氟苯尼考、苯唑西林敏感,对环丙沙星、多黏菌素B、克林霉素耐药;小鼠致病性试验显示,3.6×109cfu/只组的10只小鼠在48 h内全部死亡,且死亡小鼠呈急性脓毒败血症病变,通过Reed-Muench公式计算TA01株的LD50为1.137×108cfu/只;病理组织学检查可观察到明显的蓝染菌团,且伴有明显的中性粒细胞浸润。说明TA01株为猪2型链球菌强毒株,与我国已分离报道的链球菌菌株相比,TA01株具有毒力强、增殖快的特性。
In this test,the pathogenicity, growth and reproduction characteristics and drug resistance of Streptococcus type 2 have been studied by bacterial isolation and identification, biochemical experiments, growth curves and correlation curves between OD600 values and viable counts, drug susceptibility tests, mouse pathogenicity experiments, and histopathological observations. The results showed that Streptococcus isolated from the sick pig was identified as Streptococcus suis type 2, named TA01 strain;The TA01 strain reached the highest peak at 6-8 h, and the viable count decreased gradually after 8 h. The correlation between the number of viable bacteria and OD600 was expressed as y=24.659x-1.076 1, R2=0.996 7;Drug sensitivity test showed that TA01 strains were sensitive to penicillin, erythromycin, florfenicol, oxacillin, and resistant to tetracycline, ciprofloxacin, polymyxin B, clindamycin;All the 10 mice in the 3.6×109 cfu/each attack group died within 48 hours, and the mice died of acute septicemia;The LD50 of TA01 strain was 1.137×108 cfu/each calculated by Reed-Muench formula;Obvious blue-stained colony with obvious neutrophils could be observed under static observation by histopathology. The results indicated that TA01 strain was a virulent strain of Streptococcus suis type 2. Compared with Streptococcus suis strain reported in China, TA01 strain had strong virulence and rapid proliferation.
作者
马梓承
李焱
古金元
彭涛
刘照虎
王宏宇
孟凡亮
王方昆
刘思当
MA Zicheng;LI Yan;GU Jinyuan;PENG Tao;LIU Zhaohu;WANG Hongyu;MENG Fanliang;WANG Fangkun;LIU Sidang(Department of Animal Science and Technology,Shandong Agricultural University,Taian 271018,China;Shandong Provincial Key Laboratory of Animal Bioteehnology and Disease Control and Prevention,Shandong Agricultural University,Taian 271018,China;Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention,Taian 271018,China)
出处
《黑龙江畜牧兽医》
CAS
北大核心
2019年第1期73-76,80,178,179,共7页
Heilongjiang Animal Science And veterinary Medicine
基金
“973”国家重点基础研究发展计划项目(2017YFD0500605)
关键词
猪2型链球菌
分离鉴定
生长曲线
药敏试验
致病性
LD50测定
Streptococcus suis type 2
isolation and identification
growth curve
drug sensitivity test
pathogenicity
LD50 determination
