北京市2004年-2010年志贺菌菌型分布及毒力基因分析

Distribution of different serotypes and analysis of virulence genes in Shigella species in Beijing from 2004 to 2010

目的:了解近年来北京市志贺菌菌型变化及毒力基因分布特征。方法:对2004年-2010年监测到的1413株志贺菌进行血清分型;应用荧光PCR方法进行ipaHs、et1和sen基因的检测。结果:宋内志贺菌741株(52.4%),福氏志贺菌664株(47.0%),痢疾和鲍氏志贺菌各4株(1.2%)。福氏志贺菌共分为19种血清型,以F4c、F2a、F1a为主。宋内志贺菌自2007年首次超过福氏成为优势菌型后,所占比例逐渐加大,2010年已达到79.3%。福氏志贺菌也逐步由F4c转向以F2a为主,并伴有其它血清型交替出现。ipaH s,et1和sen三种基因的携带率分别为95.4%,82.3%和57.5%。set1和sen在福氏志贺菌的携带率明显高于宋内志贺菌。结论:近8年北京市志贺菌菌型发生了显著变化,宋内志贺菌正逐步成为主导菌型。毒力相关基因在不同菌型的分布存在差异。

Objective：To understand the changes of different serotypes of pathogenic bacteria causing the shigellosis and the distribution of virulence gene.Methods：1413 Shigella germ strains isolated from diarrhea patients were examined serotype by serum agglutination.221 strains were detected for ipaH,set1 and sen virulence gene by realtime PCR.Results：741 strains（52.4%） belonged to Shigella Sonnei,664 strains（47%） were Shigella flexneria and other 8 strains（1.2 %） respectively were Shigella dysenteriae and Shigella boydii.All the Shigella flexneria strains were composed of 19 serotypes,mainly including Shigella flexneria type 2a,4c and 1a.There is obvious difference in the distribution of the serotypes in different ages.Shigella Sonnei strains firstly became the dominant group over Shigella flexneria from 2007 and were getting prevalent the last years,reaching 79.3% in 2010.The propitiation of Shigella flexneria type 2a was increasing instead of those of 4c,with the alternate appearance of other serotypes.The distribution of ipaH,set1 and sen virulence gene among 221 strains were 95.4%,82.3% and 57.5%,respectively.The positive rate of set1 and sen virulence gene in Shigella Sonnei strains are obviously higher than those in Shigella flexneria strains.Conclusion：The distinct changes in the group and serotype of the pathogen causing shigellosis revealed that Shigella Sonnei was becoming the dominant group in Beijing.The distribution of the three virulence gene in different serotypes had difference.