Abstract

The gram-positive pathogen Streptococcus pneumoniae is the most common cause of community-acquired pneumonia and is responsible for high morbidity and mortality worldwide. A major feature of pneumococcal pneumonia is an abundant neutrophil infiltration. In this work we observed that the R6 nonencapsulated S. pneumoniae strain induced a higher oxidative burst in neutrophils compared with its capsulated progenitor D39, by triggering neutrophil NADPH oxidase to produce more reactive oxygen intermediates (ROI) and by interfering with the neutrophil kinase signalling pathway. In addition, we evaluated the possibility that the capsule, lacking in R6 but present in D39, could modulate the S. pneumoniaeinduced neutrophil respiratory burst. In this respect, three knock-out isogenic mutants (D39DCPS2E, D39DCPS-R6 and R6DCPS-R6) that were unable to synthesize the capsule, were tested for their capability of inducing the release of neutrophil-ROIs. The results indicate that the mutants behaved similarly to their wild-type parental strains in enhancing respiratory burst activity, suggesting that the capsule itself is not directly involved in modulating the neutrophil oxidative burst induced by S. pneumoniae, but that other genetic differences between D39 and R6 present elsewhere in the genome could be responsible for these mechanisms.

Autore Pugliese

• Barbuti Giovanna , Montemurro Pasqualina , Fumarulo Ruggiero

Tutti gli autori

• BARBUTI G.;MONTEMURRO P.;FUMARULO R.

Titolo volume/Rivista

Non Disponibile

Anno di pubblicazione

2010

ISSN

0928-8244

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

Non Disponibile

Numero di citazioni Scopus

8

Ultimo Aggiornamento Citazioni

Non Disponibile

Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile