Open AccessVirulence of Streptococcus pneumoniae may be determined independently of capsular polysaccharide
Author(s) -
Mizrachi Nebenzahl Y.,
Porat N.,
Lifshitz S.,
Novick S.,
Levi A.,
Ling E.,
Liron O.,
Mordechai S.,
Sahu R.K.,
Dagan R.
Publication year - 2004
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/j.femsle.2004.02.003
Subject(s) - streptococcus pneumoniae , inoculation , microbiology and biotechnology , serotype , virulence , capsule , biology , bacterial capsule , strain (injury) , streptococcaceae , bacteria , virulence factor , streptococcus , polysaccharide , immunology , antibiotics , gene , biochemistry , botany , genetics , anatomy
Mice were inoculated intranasally with Streptococcus pneumoniae isolates of serotype 14 with different genetic backgrounds (14R, 14DW) and a capsular switch of 14R, strain 9VR (serotype 9V). Inoculation of the mice with 14R and 9VR resulted in 60% mortality. All the mice survived 14DW inoculation. No differences in lungs' bacterial loads were found 3 h following inoculation. Bacterial clearance of 5 logs was observed 48 h after inoculation with 14DW versus within 1 log 48 h after inoculation with 14R and 9VR. No significant differences in bacterial size or the capsular amount could be found between 14R and 14DW. We conclude that factor(s) in addition to the capsule, contribute to disease outcome.