Abstract
Bacterial vaccines can reduce carriage rates. Colonization is usually a
binary endpoint. Real time quantitative PCR (qPCR) can quantify
bacterial DNA in mucosal samples over a wide range. Using culture and
single-gene species-specific qPCRs for Streptococcus pneumoniae (lytA), Streptococcus pyogenes (ntpC), Moraxella catarrhalis (ompJ), Haemophilus influenzae (hdp) and Staphylococcus aureus (nuc)
and standard curves against log-phase reference strain broth cultures
we described frequency and peak density distributions of carriage in
nasopharyngeal swabs from 161 healthy 2–4 y old children collected into
STGG broth. In general, detection by qPCR and culture was consistent.
Discordance mostly occurred at lower detection thresholds of both
methods, although PCR assays for S. pyogenes and S. aureus
were less sensitive. Density varied across 5-7 orders of magnitude for
the 5 species with the abundant species skewed toward high values
(modes: S. pneumoniae log3-4, M. catarrhalis & H. influenzae
log4-5 CFU/ml broth). Wide ranges of bacterial DNA concentrations in
healthy children carrying these bacteria could mean that different
individuals at different times vary greatly in infectiousness.
Understanding the host, microbial and environmental determinants of
colonization density will permit more accurate prediction of vaccine
effectiveness.
Original language | English |
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Pages (from-to) | 375-382 |
Number of pages | 8 |
Journal | Human Vaccines and Immunotherapeutics |
Volume | 12 |
Issue number | 2 |
Early online date | 14 Sep 2015 |
DOIs | |
Publication status | Published - Feb 2016 |
Keywords
- colonization
- quantitative PCR
- bacterial density
- children
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Dive into the research topics of 'Population density profiles of nasopharyngeal carriage of five bacterial species in pre-school children measured using quantitative PCR offer potential insights into the dynamics of transmission'. Together they form a unique fingerprint.Profiles
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Professor Adam H R Finn
- Bristol Medical School (PHS) - Professor of Paediatrics
- Bristol Population Health Science Institute
- Health Protection Research Unit (HPRU)
- Infection and Immunity
- Bristol Children's Vaccine Centre
- School of Cellular and Molecular Medicine - Professor of Paediatrics
Person: Academic , Member, Group lead