Observations on pathogenicity between A and B subtype of hMPV in mice

Objective To investigate the difference of pathogenicity between the two genotypes of human metapneumovirus(hMPV) for the further research.Methods At various time after hMPV infection in BALB/c mice,viral titers of lung tissue were measured by real-time RT-PCR,pathology was assessed by a histopathological scoring system,airway responsiveness was assayed by animal lung function monitoring equipment.Pathogenicity was then measured by detailed evaluation through the results above.Results There is no significant difference in weight of mice between control group and experimental group through dynamic monitoring ; though the difference was exists in airway responsiveness and pathological changes of mice between control group and experimental group,the differences were not statistically in airway reaction,pathological changes and virus drops among the three groups of experimental group.Conclusion There is no difference in pathogenicity between the two subtypes of hMPV in infection of BALB/c mice,viral genotype do not appear to be associated with pathogenicity. Key words: Human metapneumovirus (hMPV); Genotype; Pathogenicity