TY - JOUR
T1 - Intra-Species Interactions in Streptococcus pneumoniae Biofilms
AU - Valente, Carina
AU - Cruz, Ana Raquel
AU - Henriques, Adriano O.
AU - Sá-Leão, Raquel
N1 - Funding Information:
This work was supported by project PTDC/BIA-MIC/30703/ 2017 from Fundação para a Ciência e a Tecnologia (FCT), Portugal; LISBOA-01-0145-FEDER-007660 (Microbiologia Molecular, Estrutural e Celular, funded by FEDER through COMPETE2020 – Programa Operacional Competitividade e Internacionalização); and LISBOA-01-0145-FEDER-016417 (ONEIDA co-funded by Fundos Europeus Estruturais e de Investimento, Programa Operacional Regional Lisboa 2020 and Fundação para a Ciência e a Tecnologia (FCT)). CV was supported by post-doctoral fellowship from FCT SFRH/BPD/ 115280/2016. The funders had no role in the design of the study, collection, analysis, and interpretation of data, writing of the manuscript or in the decision to submit the manuscript for
Publisher Copyright:
Copyright © 2022 Valente, Cruz, Henriques and Sá-Leão.
PY - 2022/1/5
Y1 - 2022/1/5
N2 - Streptococcus pneumoniae is a human pathogen responsible for high morbidity and mortality worldwide. Disease is incidental and is preceded by asymptomatic nasopharyngeal colonization in the form of biofilms. Simultaneous colonization by multiple pneumococcal strains is frequent but remains poorly characterized. Previous studies, using mostly laboratory strains, showed that pneumococcal strains can reciprocally affect each other’s colonization ability. Here, we aimed at developing a strategy to investigate pneumococcal intra-species interactions occurring in biofilms. A 72h abiotic biofilm model mimicking long-term colonization was applied to study eight pneumococcal strains encompassing 6 capsular types and 7 multilocus sequence types. Strains were labeled with GFP or RFP, generating two fluorescent variants for each. Intra-species interactions were evaluated in dual-strain biofilms (1:1 ratio) using flow cytometry. Confocal microscopy was used to image representative biofilms. Twenty-eight dual-strain combinations were tested. Interactions of commensalism, competition, amensalism and neutralism were identified. The outcome of an interaction was independent of the capsular and sequence type of the strains involved. Confocal imaging of biofilms confirmed the positive, negative and neutral effects that pneumococci can exert on each other. In conclusion, we developed an experimental approach that successfully discriminates pneumococcal strains growing in mixed biofilms, which enables the identification of intra-species interactions. Several types of interactions occur among pneumococci. These observations are a starting point to study the mechanisms underlying those interactions.
AB - Streptococcus pneumoniae is a human pathogen responsible for high morbidity and mortality worldwide. Disease is incidental and is preceded by asymptomatic nasopharyngeal colonization in the form of biofilms. Simultaneous colonization by multiple pneumococcal strains is frequent but remains poorly characterized. Previous studies, using mostly laboratory strains, showed that pneumococcal strains can reciprocally affect each other’s colonization ability. Here, we aimed at developing a strategy to investigate pneumococcal intra-species interactions occurring in biofilms. A 72h abiotic biofilm model mimicking long-term colonization was applied to study eight pneumococcal strains encompassing 6 capsular types and 7 multilocus sequence types. Strains were labeled with GFP or RFP, generating two fluorescent variants for each. Intra-species interactions were evaluated in dual-strain biofilms (1:1 ratio) using flow cytometry. Confocal microscopy was used to image representative biofilms. Twenty-eight dual-strain combinations were tested. Interactions of commensalism, competition, amensalism and neutralism were identified. The outcome of an interaction was independent of the capsular and sequence type of the strains involved. Confocal imaging of biofilms confirmed the positive, negative and neutral effects that pneumococci can exert on each other. In conclusion, we developed an experimental approach that successfully discriminates pneumococcal strains growing in mixed biofilms, which enables the identification of intra-species interactions. Several types of interactions occur among pneumococci. These observations are a starting point to study the mechanisms underlying those interactions.
KW - biofilms
KW - co-colonization
KW - colonization
KW - competition
KW - intraspecies interactions
KW - multiple carriage
KW - Streptococcus pneumoniae
UR - http://www.scopus.com/inward/record.url?scp=85123061047&partnerID=8YFLogxK
U2 - 10.3389/fcimb.2021.803286
DO - 10.3389/fcimb.2021.803286
M3 - Article
C2 - 35071049
AN - SCOPUS:85123061047
SN - 2235-2988
VL - 11
JO - Frontiers in Cellular and Infection Microbiology
JF - Frontiers in Cellular and Infection Microbiology
M1 - 803286
ER -