Plaque formation by virulent Shigella flexneri
Autor: | E V Oaks, M E Wingfield, S B Formal |
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Rok vydání: | 1985 |
Předmět: |
Immunology
medicine.disease_cause Microbiology Shigella flexneri Tissue culture Phagocytosis Escherichia coli medicine Humans Shigella sonnei Shigella Shigella boydii Virus quantification Sereny test Virulence biology Temperature biology.organism_classification Infectious Diseases Cell culture Hybridization Genetic Parasitology Adsorption Research Article |
Zdroj: | Infection and Immunity. 48:124-129 |
ISSN: | 1098-5522 0019-9567 |
Popis: | An in vitro tissue culture plaque assay was developed to investigate the intracellular replication and intercellular spread of virulent shigellae. Shigella plaques were formed in HeLa cell monolayers in the presence of an agarose overlay containing tissue culture medium and gentamicin, which eliminated extracellular bacterial growth. Microscopically, the plaques were characterized by a central area of dead host cells surrounded by cells infected with shigellae. Cells further away from the plaque center were uninfected. Inclusion of chloramphenicol or nalidixic acid in the overlay completely abolished plaque formation. Plaque formation was completely inhibited when infected monolayers were shifted from 37 to 30 degrees C. Shifting infected monolayers from 30 degrees C, where plaques do not form, to 37 degrees C resulted in the formation of plaques. Cultures of Shigella boydii, Shigella sonnei (form I), and all six serotypes of Shigella flexneri produced plaques. Shigellae isolated from plaques were Sereny test positive, contained a 140-megadalton plasmid, and were gentamicin sensitive. Noninvasive shigellae did not form plaques. |
Databáze: | OpenAIRE |
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