胃病患者胃黏膜真菌基因的多样性

Genetic polymorphisms of fungi in gastric mucosa of patients with different gastric diseases

目的:检测人胃黏膜病损处的真菌,及其基因多样性,分析菌种进化分支与黏膜病理损伤的关系.方法:用胃镜钳取有病损的胃黏膜标本65例(慢性胃炎52例,胃溃疡11例,胃癌2例).用念珠菌显色培养基(CHROM agar)进行分离培养鉴定.对鉴定为真菌的菌株样本按照病损程度分组,随机抽取菌株样本进行ITS序列检测,并比对同源性,建立进化树,分析菌株进化分支与胃黏膜病理损伤的关系.结果:分离培养出真菌菌株34个(34/65,52.3%),真菌阳性率在慢性胃炎、胃溃疡、胃癌样本中分别为44.2%(23/52),818%(9/11),100%(2/2),差异有统计学意义(χ2=7.023,P=0.030).进行ITS序列检测的18个菌株申请GenBank序列注册号为GQ280298-GQ280334,建立系统进化树显示真菌菌株某些进化分支与胃黏膜病损有密切关系.结论:不同进化分支的真菌对胃黏膜炎症损伤的程度存在差异.

AIM：To explore the relationship between fungal evolution and the severity of gastric mucosal lesions by analyzing the genetic diversity of fungi in gastric mucosa of patients with different gastric diseases.METHODS：Sixty-five gastric mucosal specimens,including 52 chronic gastritis specimens,11 gastric ulcer specimens,and 2 gastric carcinoma specimens,were collected by gastroscopy.CHROM agar medium was used for iso-lation and identification of fungal strains.The fungal strains isolated were grouped according to the severity of lesions,and 18 strains were randomly selected to sequence the internal transcribed spacer （ITS） regions for homology comparison and phylogenetic tree building.The relationship between fungal evolution and the severity of gastric mucosal lesions was then analyzed.RESULTS：A total of 34 （34/65,52.3%） fungal strains were isolated,of which 23 （23/52,44.2%） from gastritis samples,9 （9/11,81.8%） from gastric ulcer samples,and 2 （2/2,100%） from gastric carcinoma.There was significant difference in the fungal detection rate among different groups of patients （χ^2=7.023,P=0.030）.The ITS sequences of all the 18 strains were deposited in GenBank （GenBank Accession Nos.GQ280298GQ280334）.The phylogenetic tree obtained suggested that some fungal strains in certain evolution branches were closely related to the severity of gastric mucosa lesions.CONCLUSION：The severity of gastric mucosal lesions is associated with fungal evolution directions.