1997-2010年宁夏回族自治区小肠结肠炎耶尔森菌致病性的基因特征

Characteristics of Yersinia enterocolitica genes isolated in Ningxia Hui autonomous region from 1997 to 2010

目的了解宁夏回族自治区小肠结肠炎耶尔森菌主要毒力基因分布情况和致病性小肠结肠炎耶尔森菌分子分型特征。方法于1997--2010年在宁夏回族自治区共分离得到283株小肠结肠炎耶尔森菌，用PCR法分析其黏附侵袭位点基因（ail）、耐热肠毒素A基因（ystA）、ystB、黏附素基因（yadA）、毒力活化因子基因（virF）；应用限制性内切酶NotI酶切致病性小肠结肠炎耶尔森菌染色体DNA进行脉冲场凝胶电泳（PFGE），利用BioNumerics软件进行聚类分析。结果209株O：3、O：9血清型小肠结肠炎耶尔森菌中ail、ystA、yadA、virF毒力基因阳性，ystB为阴性的占97．6％（204／209）；O：8血清型和未开展血清分型的菌株5种毒力基因全部阴性；11株O：5血清型有9株5种毒力基因全部阴性。将致病性菌株进行PFGE分型，根据染色体DNA的NotI酶切图谱，将29株O：3血清型分成12个PFGE带型，包含5株以上的优势PFGE带型有2种。180株O：9血清型菌株分成13个PFGE带型，包含10株以上的优势PFGE带型有4种，各自是从同一地区猪与家鼠、猪与犬、猪与野兔分离。结论宁夏地区O：3、O：9血清型小肠结肠炎耶尔森菌具有致病性，O：3逐步成为如今的优势血清型；O：5、O：8与血清未分型的菌株无致病性。

Objective To investigate the distribution of virulent genes of Yersinia enterocolitica （ Y. enterocolitica） in Ningxia Hui autonomous region and the characteristics of the molecular patterns of Y. enterocolitica. Methods 283 strains of Y. enterocolitica were isolated in Ningxia Hui autonomous region between year 1997 and 2010. The genes ail,ystA ,ystB, yadA and virF were analyzed by PCR method; the chromosomal DNA of Y. enterocolitica was digested by restriction endouucleases Not I and processed by pulsed-field gel electrophoreses （PFGE）; and then the cluster analysis were conducted by BioNumeric computer software towards the above resutls. Results Of all, 209 strains of serotypes O： 3 and O： 9 E enterocolitica showed positive virulence of genes ail, ystA ,yadA and virF; 97. 6% （204/209） of which, the ystB virulence were negative. The virulence of all genes in serotype 0：8 and serum-unclassified strains were negative. 9 out of 11 strains of serotype O ： 5 Y. enterocolitica showed negative virulence of the above five genes. By PFGE, according to the Not I Macrorestriction Map on chromosomal DNA, the 29 strains of scrotype O ：3 Y. enterocolitica were divided into 12 PFGE patterns,2 of which were dominant patterns which could be found in over 5 strains; and the 180 strains of serotype 0：9 Y. enterocolitica were divided into 13 patterns,4 of which were dominant patterns which existed in over 10 strains; which were isolated individually from pigs and house mouse, pigs and dogs as well as pigs and wild rabbits. Conclusion Y. enterocoliticaserotypes O： 3 and O： 9 were pathogenic in Ningxia, and serotype O： 3 becomes predominant gradually. O ：5, O ：8 and serum-unclassified serotypes were non-pathogenic.