Sigridur Quirk,
Author Of 1 Presentation
GENOMIC ANALYSES OF BACTERIOCINS IN ICELANDIC AND KENYAN PNEUMOCOCCI COLLECTED BEFORE AND AFTER PCV10 INTRODUCTION (ID 503)
- Madeleine E. Butler, United Kingdom
- Melissa J. Jansen van Rensburg, United Kingdom
- Asma Akter,
- Calum Forrest,
- Andries J. Van Tonder,
- Sigridur Quirk,
- Gunnsteinn Haraldsson, Iceland
- Stephen D. Bentley, United Kingdom
- Angela M. Karani, Kenya
- Helga Erlendsdottir, Iceland
- Asgeir Haraldsson, Iceland
- Karl G. Kristinsson, Iceland
- Anthony Scott, Kenya
- Angela Brueggemann, United Kingdom
Abstract
Background
Widespread use of pneumococcal conjugate vaccines (PCVs) perturb the bacterial population structure, the consequences of which include changes in nasopharyngeal competition among pneumococci. Bacteriocins are antimicrobial peptides produced by bacteria, and are believed to inhibit competing bacterial strains. Twenty putative pneumococcal bacteriocins have been identified: this study aims to compare the bacteriocin distribution among pneumococci recovered pre- and post-PCV10 introduction in two countries.
Methods
Carriage and disease pneumococci collected in Iceland (n=1,916) and Kenya (n=3,257) before and after PCV10 introduction were sequenced and genomes were screened for twenty different bacteriocin sequences. Significant changes in the prevalence of genetic lineages, serotypes, and bacteriocins post-PCV10 introduction were assessed.
Results
PCV10 use led to a significant reduction in the prevalence of vaccine serotypes and associated genetic lineages in both countries. Overall, 18 of 20 bacteriocins were detected in 1% to 100% of genomes. The prevalence of six bacteriocins was significantly altered in the Kenyan dataset post-PCV10, and three of these also changed in the Icelandic dataset. These bacteriocins were associated with genetic lineages that also significantly changed in prevalence.
Conclusions
The bacteriocin distribution changed significantly following PCV10 introduction in Iceland and Kenya. The biological relevance of these changes to competition dynamics is currently under investigation.