【摘要】 我们在研究伤寒沙门氏菌保护性抗原期间,发现了一个新的不耐热的伤寒沙门氏菌特异性抗原,暂时命名为θ抗原。这个抗原存在于各种类型的伤寒沙门氏菌中,并能从Ty2菌苗株细胞提取。以不吸收的抗θ兔血清作试管凝集时,与O90l和H901菌株的凝集效价分别为1:640和1:320。但与Ty2或9,12,Vi:d:-菌株不发生凝集,这一现象以后证实是由于Vi抗原的存在。θ抗原形成凝集较幔（31℃18～24小时）,其所形成的凝集块疏松,易摇散、呈半絮状。菌体经100℃30分钟加热后与θ血清不发生凝集。玻片凝集试验显示θ血清与W和V型伤寒沙门氏菌（后者须培养在含酚培养基上）在1分钟内产生明显凝集。而与大多数D群（包括D₁和D₂）沙门氏菌和其他沙门氏菌不凝集,并与下列肠杆菌科细菌亦不凝集,包括志贺氏菌属A、B、C、D群,大肠艾希氏菌O:1～25和致病性大肠艾希氏菌12个不同的血清型,3株变形杆菌以及含有α抗原的Wakefield茵。化学分析显示,粗制θ提取物含有核酸（491μg/ml）。蛋白质（39μg/ml）和KDO（23μg/ml）,但不含有O-乙酰基,表明θ抗原不同于Vi抗原。作者建议以θ血清替代现用的O:9,Vi和d因子血清作为伤寒沙门氏菌的血清学诊断。并需继续查明θ抗原的化学本质。更多还原

【Abstract】 In the course of the study on the protective antigens to S. typhi, a new thermolabile specific antigen of this microorganism was discovered and named 0 antigen tentatively. The antigen existed in various forms of S. typhi and could be extracted from the whole cells of the vaccine strain Ty2. The agglutination of θ antigen and anti-θ antibody showed some characteristics: the agglutination lump formed slowly（37℃, 18²4h）, looked fluffy semiflocculent and easy to be dispersed by shaking. After heated at 100℃ for 30 min, the organism lost its agglutination ability with anti-0 serum. Slide agglutination test showed that anti-θ sera could distinctly agglutinate with both W and V forms of S. typhi（the strains of the latter should be cultivated in a medium containing 0. 1 percent phenol）within 1 min, but could not agglutinate with most of group D （including D₁ and D₂） of S. typhi and any other members of the genera Salmonella. Positive reactions with the following strains of the family Enterobacteriaceae were listed: groups A, B, C and D of genera Shigella, 0:1²5 strains of E. coli, 12 strains of different serotypes of EPEC, 3 strains of Proteus, and the Wakefield strains containing α-antigen. Chemical analysis showed that the crude extraction of 0 antigen contained: nucleic acid（419μg/ml）, protein（39μg/ml） and KDO（23μg/ml）, but no O-acetyl groups was found. These data indicated that θ antigen was different from Vi antigen. The findings of our studies suggest that the anti-θ sera might be used for serodiagnosis of S. typhi instead of the currently available factor sera O:9, Vi and H:d.更多还原