title: Effects of Rhinovirus Infection on Nasopharyngeal Bacterial Colonization in Infants With Wild or Variant Types of Mannose-Binding Lectin and Toll-Like Receptors 3 and 4.
abstract: BACKGROUND
  Development of respiratory tract infections is determined by interactions between viruses, bacteria, and the host innate immune response. We investigated the impact of natural rhinovirus infection on nasopharyngeal bacterial colonization in infants with or without gene polymorphisms of mannose-binding lectin (MBL) and Toll-like receptors (TLRs) 3 and 4.
  
  
  METHODS
  Rhinoviruses were detected by reverse transcription-polymerase chain reaction and bacteria by culture of nasopharyngeal specimens from 2- to 3-month-old infants. Gene polymorphisms in MBL at codons 52, 54, and 57, TLR3 Leu412Phe, and TLR4 Asp299Gly were detected by pyrosequencing.
  
  
  RESULTS
  Of 337 infants, 61 were positive for rhinovirus and 187 were colonized by Streptococcus pneumoniae, Moraxella catarrhalis, Haemophilus influenzae, or Staphylococcus aureus. Gene polymorphisms of MBL were detected in 32%, TLR3 in 51%, and TLR4 in 18% of subjects. Presence of rhinovirus was associated with increased colonization by S pneumoniae in children with MBL polymorphisms (8 of 20 [40%] with rhinovirus, vs 9 of 87 [10%] without rhinovirus; P = .003), but not in those with wild-type MBL. In logistic regression analyses, S pneumoniae colonization associated with MBL variant (P = .035) and with the interaction between rhinovirus and MBL variant (P = .004), and M catarrhalis colonization associated with the detection of rhinovirus (P = .033).
  
  
  CONCLUSIONS
  The association between rhinovirus infection and nasopharyngeal pneumococcal colonization in early infancy is linked to genetic variations of MBL.
authors.affiliation: Department of Pediatrics, Turku University Hospital Turku Institute for Child and Youth Research, University of Turku.
authors.forename: Sinikka
authors.initials: S
authors.lastname: Karppinen
authors.affiliation: Department of Infectious Disease Surveillance and Control, National Institute for Health and Welfare.
authors.forename: Juho
authors.initials: J
authors.lastname: Vuononvirta
authors.affiliation: Department of Infectious Disease Surveillance and Control, National Institute for Health and Welfare.
authors.forename: Qiushui
authors.initials: Q
authors.lastname: He
authors.affiliation: Department of Virology, University of Turku, Turku, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Waris
authors.affiliation: Department of Pediatrics, Turku University Hospital Turku Institute for Child and Youth Research, University of Turku ville.peltola@utu.fi.
authors.forename: Ville
authors.initials: V
authors.lastname: Peltola
keywords: Toll-like receptor 3; Toll-like receptor 4; mannose-binding lectin; rhinovirus; single nucleotide polymorphisms; viral–bacterial interaction