Nicas T I, Iglewski B H
Infect Immun. 1984 Aug;45(2):470-4. doi: 10.1128/iai.45.2.470-474.1984.
Exoenzyme S is an extracellular product of Pseudomonas aeruginosa. This enzyme catalyzes the transfer of ADP-ribose from NAD to a number of as yet unidentified eucaryotic proteins, but it is distinct from toxin A. To evaluate the role of exoenzyme S in the pathogenicity of P. aeruginosa, we isolated transposon-induced mutants of strain 388, a clinical isolate that produces exoenzyme S but no toxin A. The transposon Tn1 was introduced by using a temperature-sensitive derivative of plasmid RP1. A Tn1-induced mutant was found which had no detectable exoenzyme S activity or antigen in culture supernatants or in cell lysates. Except for its lack of exoenzyme S and resistance to carbenicillin, this mutant was indistinguishable from the parent strain. When tested in an experimental mouse burn infection model, this Tn1-induced mutant was reduced in virulence by at least 2,000-fold, suggesting a role for exoenzyme S in the virulence of this strain.
外毒素S是铜绿假单胞菌的一种胞外产物。这种酶催化ADP核糖从NAD转移到一些尚未鉴定的真核蛋白质上，但它与毒素A不同。为了评估外毒素S在铜绿假单胞菌致病性中的作用，我们分离了388菌株的转座子诱导突变体，388菌株是一种临床分离株，能产生外毒素S但不产生毒素A。通过使用质粒RP1的温度敏感衍生物导入转座子Tn1。发现一个Tn1诱导的突变体，其培养上清液或细胞裂解物中没有可检测到的外毒素S活性或抗原。除了缺乏外毒素S和对羧苄青霉素耐药外，该突变体与亲本菌株没有区别。在实验性小鼠烧伤感染模型中进行测试时，这个Tn1诱导的突变体的毒力降低了至少2000倍，这表明外毒素S在该菌株的毒力中起作用。
