黑龙江地区断奶仔猪腹泻大肠杆菌种系类群、血清型和毒力基因分析

Virulence genes of E.coli isolated from piglets with post-weaning diarrhea in Heilongjiang and their relationship with phylogenetic groups and O-serogroups

揭示黑龙江地区集约化猪场仔猪断奶腹泻(PWD)直肠棉拭子分离到的123株大肠埃希菌所属种系分类群、O血清型及其与毒力基因的特征。采用常规凝集试验进行测定,种系分类群标记的chuA、yjaA基因和TSPE4.C2DNA片段及肠毒素基因STa、STb、LT、SLT2e采用PCR方法检测。在123株分离菌株中,除21株未定型、10株自凝外,测定出92株分离的血清型,覆盖18个血清型,其中以O 8、O 9、O 149 3种血清型为主,共57株,占定型菌株的61.96%。环境共生的种系进化A群113株占91.87%,肠外强致病D种系进化群2株占1.63%。肠毒素检出菌株74,占分离株的60.16%,其中以STa、STb为主,共占肠毒素检出株的94.59%。结果显示黑龙江省PWD病原性大肠埃希菌优势血清型为O 8、O 9、O 149,大肠埃希菌肠毒素主要毒力因子为STa、STb,种系进化群为A。

We determined the relationship of virulence genes with phylogenetic groups and Osero groups Escherichia coli isolated from piglets with postweaning diarrhea in Heilongjiang. 123 E. coli isolates were serogrouped with Oantisera and detected for genes of enterotoxins STa, STb, LT and SLT2e and phylogenetic markers of chuA,yjaA and TSPE4. C2 by PCR. The result showed that among 123 isolates,92 were placed in serogroups,21 were unable to be serogrouped, and the rest 10 autoagglutinated. These isolates distributed in 18 serogroups and 61. 96% be longed to 3 Oserogroups,O 8,0 9 and O 149.91.87O./oo of E. coli isolates belonged to group A and 1.63% to group D. Enterotoxigenic E. coli accounted for 74 and 60. 16%, of which harbored the genes for the predominant enterotox was STa and STb, amounted to 94.59 %, and pathogenic E. coli isolates collected from piglets with PWD of Heilongjiang province covered at least 18 Osero types and the predominant serotypes were O 8, O 9 and O 149, predominant E. coli isolates be longed to phylogenetic group A,E. coli causing PWD were mostly enterotoxigenic with the pre dominant enterotoxins STa,STb.