title: Long-term impairment of Streptococcus pneumoniae lung clearance is observed after initial infection with influenza A virus but not human metapneumovirus in mice.
abstract: Human metapneumovirus (hMPV) is a paramyxovirus responsible for respiratory tract infections in humans. Our objective was to investigate whether hMPV could predispose to long-term bacterial susceptibility, such as previously observed with influenza viruses. BALB/c mice were infected with hMPV or influenza A and, 14 days following viral infection, challenged with Streptococcus pneumoniae. Only mice previously infected with influenza A demonstrated an 8% weight loss of their body weight 72 h following S. pneumoniae infection, which correlated with an enhanced lung bacterial replication of >7 log(10) compared with pneumococcus infection alone. This enhanced bacterial replication was not related to altered macrophage or neutrophil recruitment or deficient production of critical cytokines. However, bacterial challenge induced the production of gamma interferon in bronchoalveolar lavages of influenza-infected mice, but not in those of hMPV-infected animals. In conclusion, hMPV does not cause long-term impairment of pneumococcus lung clearance, in contrast to influenza A virus.
authors.affiliation: Research Center in Infectious Diseases of the 'Centre Hospitalier Universitaire de Québec' and Laval University, Québec City, QC, G1V 4G2, Canada.
authors.forename: Herbert P
authors.initials: HP
authors.lastname: Ludewick
authors.affiliation: Research Center in Infectious Diseases of the 'Centre Hospitalier Universitaire de Québec' and Laval University, Québec City, QC, G1V 4G2, Canada.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Aerts
authors.affiliation: Research Center in Infectious Diseases of the 'Centre Hospitalier Universitaire de Québec' and Laval University, Québec City, QC, G1V 4G2, Canada.
authors.forename: Marie-Eve
authors.initials: ME
authors.lastname: Hamelin
authors.affiliation: Research Center in Infectious Diseases of the 'Centre Hospitalier Universitaire de Québec' and Laval University, Québec City, QC, G1V 4G2, Canada.
authors.forename: Guy
authors.initials: G
authors.lastname: Boivin
mesh_terms: D000818:Animals; D016207:Cytokines / Q000276:immunology; D004195:Disease Models, Animal; D004198:Disease Susceptibility; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology / Q000502:physiology*; D007251:Influenza, Human / Q000276:immunology* / Q000382:microbiology / Q000821:virology; D008168:Lung / Q000382:microbiology* / Q000821:virology*; D029121:Metapneumovirus / Q000276:immunology / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D018184:Paramyxoviridae Infections / Q000276:immunology* / Q000382:microbiology / Q000821:virology; D011018:Pneumonia, Pneumococcal / Q000276:immunology* / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000276:immunology / Q000502:physiology*
chemical_list: D016207:Cytokines