title: Enhanced adherence of Streptococcus pneumoniae to human epithelial cells infected with respiratory syncytial virus.
abstract: In the present study, we analyzed the effect of a preceding respiratory syncytial virus (RSV) infection of human respiratory epithelial cells on the adherence of Streptococcus pneumoniae tested by means of a cytometric fluorescence assay. Adherence of clinically relevant pneumococcal serotypes 3, 9, 14, 18, 19, and 23 was studied using uninfected and RSV-infected monolayers. To this end, monolayers of both human nasopharyngeal cells (HEp-2) and pneumocyte type II cells (A549) were infected with RSV serotype A. Adherence to uninfected epithelial cells varied between pneumococcal serotypes. After RSV infection of the monolayers, all serotypes showed a strongly (2- to 10- fold) and significantly increased adherence when compared with adherence to uninfected monolayers. Enhanced adherence was observed with both cell lines. By fluorescence and scanning electron microscopy, we observed redistribution of pneumococcal adherence over the epithelial surface due to RSV infection, with dense bacterial accumulations near to epithelial syncytia.
authors.affiliation: Department of Paediatrics Infectious Diseases, Wilhelmina Children's Hospital, Room KE 04.136.2, Lundlaan 6, 3508 AB Utrecht, The Netherlands.
authors.forename: Jeanne-Marie
authors.initials: JM
authors.lastname: Hament
authors.forename: Piet C
authors.initials: PC
authors.lastname: Aerts
authors.forename: Andre
authors.initials: A
authors.lastname: Fleer
authors.forename: Hans
authors.initials: H
authors.lastname: Van Dijk
authors.forename: Theo
authors.initials: T
authors.lastname: Harmsen
authors.forename: Jan L L
authors.initials: JL
authors.lastname: Kimpen
authors.forename: Tom F W
authors.initials: TF
authors.lastname: Wolfs
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology*; D002460:Cell Line; D004847:Epithelial Cells / Q000382:microbiology / Q000821:virology; D006801:Humans; D008855:Microscopy, Electron, Scanning; D012136:Respiratory Syncytial Viruses / Q000472:pathogenicity*; D012137:Respiratory System / Q000166:cytology / Q000382:microbiology / Q000821:virology; D013296:Streptococcus pneumoniae / Q000145:classification / Q000472:pathogenicity* / Q000502:physiology* / Q000648:ultrastructure; D015163:Superinfection