English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background  Many surface proteins thought to promote  Streptocococcus pneumoniae  virulence have recently been discovered and are currently being considered as future vaccine targets. We assessed the prevalence of 16 virulence genes among 435  S .  pneumoniae  invasive isolates from France and the “African meningitis belt” region, with particular focus on serotype 1 (Sp1), to compare their geographical distribution, assess their association with site of infection and evaluate their potential interest as new vaccine candidates.    Methods  Detection by PCR of  pspA  (+families),  pspC  (+ pspC . 4 ),  pavA ,  lytA ,  phtA , B , D , E ,  nanA , B , C ,  rrgA  (Pilus-1),  sipA  (Pilus-2),  pcpA  and  psrp  was performed on all isolates, as well as antibiotic resistance testing and MLVA typing (+MLST on 54 representative strains). Determination of  ply  alleles was performed by sequencing (Sp1 isolates).    Results  MLVA and virulence genes profiles segregated Sp1 isolates into 2 groups that followed continent distribution. The  ply  allele 5 and most of the genes that were variable ( nanC , Pilus-2,  psrp ,  pcpA ,  phtD ) were present in the French Sp1 isolates (PMEN clone Sweden 1 -28, ST306) but absent from the African ones. Whereas all African Sp1 isolates clustered into a single MLST CC (CC217), MLVA distinguished two CCs that followed temporal evolution. Pilus-2 and  psrp  were more prevalent in bacteraemic pneumonia yielded isolates and  phtB  in meningitis-related isolates. Considering vaccine candidates,  phtD  was less prevalent than anticipated (50%) and  pcpA  varied importantly between France and Africa (98% versus 34%). Pilus-1 was carried by 7-11% of isolates and associated with β-lactams resistance.    Conclusions  Most virulence genes were carried by the European ST306 clone but were lacking on Sp1 isolates circulating in the African meningitis belt, where a more serious pattern of infection is observed. While virulence proteins are now considered as vaccine targets, the geographical differences in their prevalence could affect the efficacy expected from future vaccines.

Virulence Factors of Streptococcus pneumoniae. Comparison between African and French Invasive Isolates and Implication for Future Vaccines