The three extra-cellular zinc metalloproteinases of <it>Streptococcus pneumoniae </it>have a different impact on virulence in mice

• Main Authors: Pozzi Gianni, Iannelli Francesco, Maggi Tiziana, Memmi Guido, Chiavolini Damiana, Oggioni Marco R
• Format: Article
• Language: English
• Published: BMC 2003-07-01
• Series: BMC Microbiology
• Online Access: http://www.biomedcentral.com/1471-2180/3/14

<p>Abstract</p> <p>Background</p> <p><it>Streptococcus pneumoniae </it>possesses large zinc metalloproteinases on its surface. To analyse the importance in virulence of three of these metalloproteinases, intranasal challenge of MF1 outbred mice was carried out using a range of infecting doses of wild type and knock-out pneumococcal mutant strains, in order to compare mice survival.</p> <p>Results</p> <p>Observation of survival percentages over time and detection of LD₅₀s of knock out mutants in the proteinase genes in comparison to the type 4 TIGR4 wild type strain revealed two major aspects: i) Iga and ZmpB, present in all strains of <it>S. pneumoniae</it>, strongly contribute to virulence in mice; (ii) ZmpC, only present in about 25% of pneumococcal strains, has a lower influence on virulence in mice.</p> <p>Conclusions</p> <p>These data suggest Iga, ZmpB and ZmpC as candidate surface proteins responsible for pneumococcal infection and potentially involved in distinct stages of pneumococcal disease.</p>