新肠道菌毒素CLDT的初步研究

Study on a New Cytolethal Distending Toxin(CLDT)

本文报道对一种新的细胞膨胀致死毒素(CytolethalDistending Toxin)实验研究结果。实验证明,CLOT 能使敏感细胞 CHO,Vero,HeLa 产生扩展、膨胀为形态学特征的病变,对 Y—1细胞不产生病变,因而能与巳知大肠杆菌肠毒素 LT、VT 等相鉴别。应用组织培养细胞检测肠杆菌的 CLOT 毒素,在大肠杆菌属、志贺氏菌属及弯曲菌属均可检出。大肠杆菌检出5株(5/257),血清型为 O_(50):NM 和 O_(86):H_(34);志贺氏菌属14株(14/14),血清型为痢疾志贺氏 A_2型和鲍氏7型;弯曲菌属13株(13/20),包括空肠弯曲菌、胎儿弯曲菌及 CNW 三个种。

A new cytolethal distending toxin (CLDT) which is cytolethal to CHO,Vero and Hela cells and nontoxic to Y-1 cells has been demonstrated in the culture filtrates of E.coll O_(128):NM strain. CLDT was distinct from the classic heat—labile enterotoxin(LT) and Vero cell toxins. CLDT was detected in the culture filtrates from some strains of E.coll,Campylobacter and Shigella associated with diarrheal dis- ease.Highest titer of CLDT was obtained when the bacterium was grown in Evan's medium as shaking culture for 48 h.Although CLDT was heat-labile at 70℃ for 60 min,the titers of the toxin could be maintained at-70℃ for longer than 6 months.The toxin demonstrated a molecular weight over 30000.