福氏志贺菌4c亚型深圳分离株的病原特性及毒力基因分析

Pathogenic and virulence gene analysis on shigella flexneri 4c subserotype isolated for the first time in Shenzhen

目的对深圳市首次分离的福氏志贺菌4c亚型菌株进行病原学分析,了解该类新菌型特征。方法采用生化反应、血清学分型、刚果红侵袭试验、药敏分析等方法对从患者、厨工肛拭及物体表面等样本中分离的17株福氏志贺菌分离株进行病原学分析,并对ipaH、ial、sen、set4个毒力基因进行PCR检测。结果所得到的17株福氏志贺菌4c亚型分离菌均分解葡萄糖产酸不产气,甘露醇阳性,血清学鉴定均为福氏志贺菌IV型、7群菌株,刚果红侵袭试验均阳性,均对氨卞西林、四环素、红霉素、甲氧苄啶、阿莫西林耐药,而对阿米卡星、环丙沙星、庆大霉素、头孢噻肟、头孢噻吩和诺氟沙星敏感,所有菌株均携带ipaH和set基因,而仅有23.53%(4/17)的菌株携带ial和sen基因。结论该福氏志贺菌4c亚型深圳分离株的生化、血清学鉴定结果与报道福氏志贺菌4c亚型基本相符,该菌具备一定毒力,ipaH和set毒力基因携带情况与相关报道相符,ial和sen基因携带情况低于现有报道。

Objective To investigate the pathogenic characteristics of shigella flexneri 4c subtype isolated for the first time in Shenzhen. Methods Pathogenic analysis of 17 stains of shigellaflexneri isolated from rectal swabs of patients and the kitchen workers, and objective surface were conducted by using biochemical reaction, serosubtyping, Congo red binding ability, and antimicrobial sensitivity test. Genes of ipaH, ial, sen and set were detected by PCR. Results All isolates of shigellaflexneri 4c subtype were fermented glucose and mannitol positive, shigella flexneri type IV, group 7 serotype, and Congo red binding ability tests positive. The isolates were resistant to ampicillin, tetracycline, erythromycin,trimethoprim and amoxicillin, while sensitive to amikacin, ciprofloxacin, gentamicin, cefotaxime, cefalotin and norfloxacin. IpaH and set genes were present in all strains, while ial and sen genes were only present in 23.53% （4/17） strains. Conclusion The biochemical characterization and serotype of the isolates were similar to that reported. Congo red binding positive ability reflected the bacteria have some virulence, lal and sen vir- ulence gene was absent in most of the strains.