Evgenia M. Dragunsky , Carole R. Wooden , Susan A. Vargo , Inessa S. Levenbook
{"title":"Salmonella typhi vaccine strain in vitro; low infectivity in human cell line U937","authors":"Evgenia M. Dragunsky , Carole R. Wooden , Susan A. Vargo , Inessa S. Levenbook","doi":"10.1016/S0092-1157(89)80006-X","DOIUrl":null,"url":null,"abstract":"<div><p><em>Salmonella typhi</em> strain Ty21a has been used for live oral vaccine. The infectivity of Ty21a, in comparison with <em>S. typhi</em> Ty2, was evaluated using the human monocyte-macrophage cell line U937. Assays were performed by quantitative microscopy and viable count technique. Ty2 infected approximately 100% of the cells, multiplied extensively within these cells and caused cell death. The same dose of Ty21a infected only about 15% of the cells, resulting in a low number of intracellular bacilli and cell survival. The use of gentamicin in the test confirmed intracellular multiplication of Ty2 but not Ty21a. The system described may be suitable as a test system for characterization of the degree of virulence of Ty2 la and other live, oral typhoid vaccines.</p></div>","PeriodicalId":75991,"journal":{"name":"Journal of biological standardization","volume":"17 4","pages":"Pages 353-360, IN4"},"PeriodicalIF":0.0000,"publicationDate":"1989-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0092-1157(89)80006-X","citationCount":"11","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of biological standardization","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S009211578980006X","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 11
Abstract
Salmonella typhi strain Ty21a has been used for live oral vaccine. The infectivity of Ty21a, in comparison with S. typhi Ty2, was evaluated using the human monocyte-macrophage cell line U937. Assays were performed by quantitative microscopy and viable count technique. Ty2 infected approximately 100% of the cells, multiplied extensively within these cells and caused cell death. The same dose of Ty21a infected only about 15% of the cells, resulting in a low number of intracellular bacilli and cell survival. The use of gentamicin in the test confirmed intracellular multiplication of Ty2 but not Ty21a. The system described may be suitable as a test system for characterization of the degree of virulence of Ty2 la and other live, oral typhoid vaccines.