由病原体通过细胞壁向外分泌的毒素为外毒素。

The toxin may be formed within the pathogen and released when it dies (endotoxin), or secreted through its cell wall (exotoxin).

结论：利用噬菌体抗体库技术筛选可得到与破伤风外毒素特异性结合的人抗破伤风类毒素基因工程抗体。

Conclusion: Human genetic engineering antibody, which is able to react specifically to tetanus toxin, is obtained through screening phage antibody library.

提示细胞壁缺陷变异可影响白喉棒状杆菌产生白喉毒素蛋白质，从而使其丧失了产生外毒素致病的作用。

And no diphtherotoxin was detected in its soluble metabolites indicating that cell wall defect might affect the production of diphtherotoxin, therefore lost its pathogenic role in exotoxin production.