Allelic Diversity of zmpB Contributes to Complicated Pneumonia Caused by Streptococcus pneumoniae

Complicated pneumonia, including necrotizing pneumonia, lung abscess, and empyema ，臼used by Streptococcus pneumoniae has been increasing.
To study its virulence in an animal model and identify virulence factors of S. pneumoniae associated w ith this emerging infectious disease. We used
a young mouse inoculation model to monitor bacterial virulence and a microarray to compare gene expression between S. pneumoniae from children
with ∞mpli臼ted and non-∞mpli開始d pneumonia. We established a novel model of complicated pneumonia in young mice infected with strains of
the m司or pulse-field gel electrophoresis (PFGE) type of serotype 14 of S. pneumoniae found in children with complicated pneumonia (NTUH-p28
and NTUH-p15, ST46). In a microarray analys 惱， differences in zmpB RNA hybridization between NTUH-p28 and a strain, NTUH-p3 (ST328), from a
child with pneumococcal lobar pneumonia, were found. Confirmatory assays revealed sequence variation in the zmpB gene between the two strains
(NTUH-p28 and NTUH-p15) from complicated pneumonia and that from non-complicated pneumonia (NTUH-p3). Infection with the 6 zmpB mutant
of NTUH-p15 showed a significant decrease in the severity of pneumonia and no destructive lung injury. The zmpB ∞mplementation strain of NTUHp15
significantly restored the level of inflammation and 臼used lung neαosis . Complemen個tion of the 6 zmpB mutant of NTUH-p3 with zmpB of
NTUH-p15 resulted in a higher bacterial burden than that in wild type NTUH-p3. In conclusion, allelic diversity of zmpB a仟ects the virulence of S.
pneumoniae. zmpB of NTUH-p15 is an important virulence factor in S. pneumoniae causing complicated pneumonia in children.