宁波福氏c亚型志贺菌病原学特征、耐药性和毒力基因分布

Pathogenic characteristics,drug resistance and distribution of virulence genes of Shigella flexneri c in Ningbo

目的了解宁波地区福氏c亚型志贺菌病原学特征、耐药性和毒力基因分布,为细菌性痢疾的有效防控提供依据。方法收集来自腹泻患者的志贺菌株,对其进行生化鉴定、血清分型、药敏试验和5种毒力基因检测。结果 149株菌株中福氏(B群)志贺菌占63.76%,其中福氏1c、2c和4c亚型占36.91%;宋内(D群)志贺菌占36.24%;未检出A群和C群志贺菌。福氏1c、2c和4c亚型菌株生化结果与ATCC标准菌株一致;血清凝集抗原结构式分别为Ⅰ∶7(8)、Ⅱ∶3,4∶7(8)和Ⅳ∶7(8),均为多耐药性菌株;5种毒力基因(ipa H、set1、sen、ial和vir A)的阳性率分别为100.00%、85.45%、85.45%、90.91%和87.27%。43株菌株(78.18%)携带全部毒力基因。结论福氏c亚型志贺菌已成为宁波地区主要流行株之一,除血清变异外,生化等生物学特性未变异,菌株为多重耐药菌,携带多种毒力基因,有较强的致病力,应加强志贺菌检测与菌型分析。

Objective To investigate the pathogenic characteristics,drug resistance and virulence genes of Shigella flexneri c in Ningbo and to prevent and control bacterial dysentery. Methods The Shigella strains was collected from the patients with diarrhea. Biochemical identification,serum typing,drug sensitivity test and 5 kinds of virulence gene detection were conducted.Results Shigella accounted for 63. 76% in 149 Shigella flexneri（ B group）,in which the strains of Shigella flexneri 1c,2c and4 c accounted for 36. 91%; Shigella sonnei（ D group） accounted for 36. 24%. The group A and C of Shigella were not detected. The biochemical results of the subtype strains of Shigella flexneri 1c,2c and 4c were consistent with the ATCC standard strains. The serum agglutination antigen structure were Ⅰ： 7（ 8）,Ⅱ∶3,4∶7（ 8） and Ⅳ∶7（ 8） accordingly. All the strains resisted to multiple antibiotics. The positive rate of 5 virulence genes（ ipa H,set1,sen,ial and vir A） were 100. 00%,85. 45%,85. 45%,90. 91% and 87. 27%,respectively. 43 strains（ 78. 18%） carried 5 virulence genes. Conclusion The strains belonged to Shigella flexneri c serotype have become one of the major epidemic strains in Ningbo. Biochemical and biological characteristics of them have no variation except for the variation of serum. All the strains showed strong pathogenicity and resistant to multiple antibiotics,carrying a variety of virulence genes with stronger pathogenicity. Shigella detection and bacterial analysis should be strengthened.