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In Vitro Assay of Bacterial Adhesion onto Mammalian Epithelial Cells
Published on: May 16, 2011
Bacterial adherence to virus-infected cells: a cell culture model of bacterial superinfection
Abstract:
MDCK cells (a line of stable canine kidney cells) infected with influenza A/NWS/33 virus (a neurotropic variant of the Wilson Smith strain) were tested with 18 selected bacterial species to determine whether mammalian cells become susceptible to bacterial adherence as a result of virus infection. Cell monolayers were washed and examined microscopically for adherence. Bacteria of only two of 18 species were seen to adhere to the infected cells: a group B Streptococcus and Streptococcus sanguis. Control monolayers were negative for adherence. Pretreatment of virus-infected cultures with mouse ascitic fluid containing antibody to influenza A virus completely blocked adherence of the bacteria. Further testing with the strains representative of the five serotypes of group B Streptococcus disclosed that adherence occurred with types Ia, Ic, and II, but not with types Ib and III.
Insights
Influenza A virus infection makes canine kidney cells susceptible to adherence by specific bacteria, including certain group B Streptococcus strains. This viral-induced change in cell surface properties facilitates bacterial attachment.
Area of Science:
- Microbiology
- Virology
- Cell Biology
Background:
- Mammalian cell susceptibility to bacterial adherence can be influenced by viral infections.
- Understanding these interactions is crucial for studying host-pathogen dynamics.
Purpose of the Study:
- To investigate if influenza A virus infection alters Madin-Darby canine kidney (MDCK) cell susceptibility to bacterial adherence.
- To identify specific bacterial species that adhere to virus-infected cells.
Main Methods:
- MDCK cells were infected with influenza A virus.
- Virus-infected and control cell monolayers were exposed to 18 bacterial species.
- Adherence was assessed microscopically after washing.
- Antibody treatment was used to block adherence.
Main Results:
- Only two bacterial species, a group B Streptococcus and Streptococcus sanguis, adhered to infected MDCK cells.
- No adherence was observed on control monolayers.
- Antibody against influenza A virus blocked bacterial adherence.
- Among group B Streptococcus serotypes, Ia, Ic, and II adhered, but Ib and III did not.
Conclusions:
- Influenza A virus infection confers susceptibility to bacterial adherence on MDCK cells.
- Specific Streptococcus strains, notably certain group B types, can exploit this virus-induced change for attachment.
