A normally harmless bacterial biofilm can take a dangerous turn when exposed to a virus.
Streptococcus pneumoniae can trigger bacterial pneumonia, but also colonizes the nose or throat passages of up to 15% of healthy adults. To learn how it might become pathogenic, researchers led by Anders Hakansson at the State University of New York in Buffalo grew films of S. pneumoniae on a layer of human epithelial cells of the type that normally lines airways.
Infecting the epithelial cells with influenza virus caused bacteria to disperse from the biofilms, as did mimicking flu-induced conditions such as fever. Dispersed S. pneumoniae invaded normally uncolonized sites including the lung and middle ear in mouse studies, where they caused oedema and inflammation. They also had a more virulent gene-expression pattern than bacteria growing in biofilms or in standard laboratory conditions. 'Interkingdom signalling' could be key to inducing disease, the authors say.
About this article
Cite this article
Flu makes bacteria go bad. Nature 500, 124 (2013). https://doi.org/10.1038/500124b