Nasopharyngeal competition dynamics are likely to be altered following vaccine introduction : bacteriocin prevalence and diversity among Icelandic and Kenyan pneumococci

• Published in: Microbial Genomics
• Main Authors: Butler, Madeleine E B, Jansen van Rensburg, Melissa J, Karani, Angela, Mvera, Benedict, Akech, Donald, Akter, Asma, Forrest, Calum, van Tonder, Andries J, Quirk, Sigríður Júlía, Haraldsson, Gunnsteinn Ægir, Bentley, Stephen D, Erlendsdóttir, Helga, Haraldsson, Ásgeir, Kristinsson, Karl Gústaf, Scott, J Anthony G, Brueggemann, Angela B
• Other Authors: Other departments, Clinical Laboratory Services, Diagnostics and Blood Bank, Faculty of Medicine
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2023
• Subjects: Sýklafræði; Barnalæknisfræði; Náttúrufræðingar; Streptococcus pneumoniae/genetics; Bacteriocins; Kenya/epidemiology; Prevalence; Iceland/epidemiology; Vaccines; pneumococcus; competition; vaccine-mediated changes; Genetics; Molecular Biology; Epidemiology; Microbiology; Iceland
• Online Access: https://hdl.handle.net/20.500.11815/4436; https://doi.org/10.1099/mgen.0.001060

Funding Information: This work was funded by a Wellcome Trust Investigator Award to ABB (206394/Z/17/Z). MEBB was funded by a Wellcome Trust PhD Studentship (215112/Z/18/Z). JAGS was funded by a Wellcome Trust Senior Research Fellowship (098532). The PubMLST infrastructure is funded by a Wellcome Trust Biomedical Resource Grant awarded to ABB, Professor Martin CJ Maiden and Dr Keith A Jolley at the University of Oxford (218205/Z/19/Z). Publisher Copyright: © 2023 The Authors. Bacteriocins are antimicrobial peptides produced by bacteria to inhibit other bacteria in the surrounding environment. Streptococcus pneumoniae is a leading cause of disease worldwide and colonises the healthy human nasopharynx, where it competes for space and nutrients. Pneumococcal conjugate vaccines have reduced the incidence of disease, but they also restructure the bacterial population, and this restructuring likely alters the nasopharyngeal competition dynamics. Here, the distribution of bacteriocins was examined in over 5000 carriage and disease-causing pneumococci from Iceland and Kenya, recovered before and after the introduction of pneumococcal vaccination. Overall, up to eleven different bacteriocin gene clusters were identified per pneumococcus. Significant differences in the prevalence of bacteriocins were observed before and after vaccine introduction, and among carriage and disease-causing pneumococci, which were largely explained by the bacterial population structure. Genetically similar pneumococci generally harboured the same bacteriocins although sometimes different repertoires of bacteriocins were observed, which suggested that horizontal transfer of bacteriocin clusters had occurred. These findings demonstrated that vaccine-mediated changes in the pneumococcal population altered the prevalence and distribution of bacteriocins. The consequences of this for pneumococcal colonisation and disease remain to be determined. Peer reviewed