fa fish disease fish disease پژوهشي Orginal research papers <p dir="ltr" style="text-align: justify;"><em>Yersinia enterocolitica</em> is an important pathogen to animals and humans. Thirteen strains of <em>Y. enterocolitica</em> were isolated from diseased fish. The partial 16SrDNA gene, five virulence genes, pathogenicity, and drug resistance of <em>Y. enterocolitica</em> strain G6029 were studied using molecular biological technology and toxicological method. Results showed that the length of amplified 16SrDNA sequence was 1448bp, and revealed 99% homology with <em>Y. enterocolitica</em>. Its GenBank accession number was JX855135. Five virulence genes (ail, ystB, yadA, virF and HPIint) were detected, and only yadA gene was not seen. Twenty-eight crucian carps that were injected with strain G6029 died within a week, and the mortality was 93.3%, indicating highly pathogenic attribute of this strain. <a href="app:ds:in">In</a> <a href="app:ds:addition">addition</a>, the strain G6029 was resistant to four antibiotics <em>(sulfafurazole, furazolidone, enrofloxacin and norfloxacin), </em>but it was susceptible to six antibiotics (florfenicol, vibramycin, cefaloridine, ciprofloxacin, streptomycin, and ampicillin). Further study of pathogenicity of <em>Y. enterocolitica</em> in teleost fish is suggested.</p> Yersinia enterocolitica, Virulence gene, Pathogenicity, Carassius auratus 402 414 http://jifro.ir/browse.php?a_code=A-10-1272-171&slc_lang=fa&sid=1 L. Wang qinxin916@aliyun.com 100319475328460015502 100319475328460015502 Yes