Density, Serotype Diversity, and Fitness of<i>Streptococcus pneumoniae</i>in Upper Respiratory Tract Cocolonization With Nontypeable<i>Haemophilus influenzae</i>

Lewnard, Joseph A; Huppert, Amit; Givon-Lavi, Noga; Pettigrew, Melinda M.; Regev‐Yochay, Gili; Dagan, Ron; Weinberger, Daniel M

doi:10.1093/infdis/jiw381

Cited by 26 publications

(23 citation statements)

References 45 publications

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“…No testing of viruses or detection of other colonizing bacteria such as Haemophilus influenzae that can influence the density and dynamics of pneumococcal carriage was conducted (Dunne et al, 2018;Chien et al, 2013;Lewnard et al, 2016). The positive association between URTI symptoms and pneumococcal carriage rates and density observed in this study is consistent with several studies reporting increased pneumococcal density during viral URTIs (Vu et al, 2011;Morpeth et al, 2018).…”

Section: Discussionsupporting

confidence: 87%

Pneumococcal carriage, density, and co-colonization dynamics: A longitudinal study in Indonesian infants

Murad

Dunne

Sudigdoadi

et al. 2019

International Journal of Infectious Diseases

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Nasopharyngeal carriage of Streptococcus pneumoniae underpins disease development and transmission. This study was performed to examine pneumococcal carriage dynamics, including density and multiple serotype carriage, in Indonesian infants during the first year of life. Methods: Two hundred healthy infants were enrolled at 2 months of age. Eight nasopharyngeal swabs were collected from enrolment until 12 months of age. Pneumococci were detected using quantitative PCR and serotyped by microarray. Regression models assessed factors influencing pneumococcal carriage and density. Results: Eighty-five percent of infants carried pneumococci at least once during the study. The median age at first acquisition was 129 days (interquartile range 41-216 days). The median duration of carriage was longer for the first pneumococcal acquisition compared with subsequent acquisitions (151 days vs. 95 days, p < 0.0001). Of the 166 infants who carried pneumococci during the study, the majority (63.9%) carried a single pneumococcal serotype at a time. Pneumococcal carriage density was higher when upper respiratory tract infection symptoms were present, lower during antibiotic usage, decreased with age, and tended to decrease over time during a carriage episode. Conclusions: The majority of Indonesian infants carry pneumococcus at least once during the first year of life. Pneumococcal carriage is a dynamic process, with pneumococcal density varying during a carriage episode.

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Section: Discussionsupporting

confidence: 87%

Pneumococcal carriage, density, and co-colonization dynamics: A longitudinal study in Indonesian infants

Murad

Dunne

Sudigdoadi

et al. 2019

International Journal of Infectious Diseases

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“…Pneumococcal serotype distribution in single-species and mixed-species colonization and otitis media. If serotype factors play a role in progression of pneumococcal colonization to OM, the diversity of serotypes isolated from MEF would be expected to differ from the diversity of serotypes carried in the nasopharynx (23). To investigate this hypothesis, we calculated Simpson's diversity index (D) values for pneumococcal serotypes isolated from MEF and from carriage, with and without cooccurring NTHi, and tested for differences in serotype diversity (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The prevalence of nasopharyngeal S. pneumoniae and NTHi carriage was monitored in a preimplementation trial of PCV7 dosing schedules, where receipt of a first vaccine dose was randomized to the period between 2 and 18 months of age (22); data regarding pneumococcal and NTHi cocolonization have been published previously (17,23). We included data from all visits by unvaccinated children at up to the age of 18 months.…”

Section: Methodsmentioning

confidence: 99%

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Pneumococcal Phenotype and Interaction with Nontypeable Haemophilus influenzae as Determinants of Otitis Media Progression

et al. 2018

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All-cause otitis media (OM) incidence has declined in numerous settings following introduction of pneumococcal conjugate vaccines (PCVs) despite increases in carriage of nonvaccine pneumococcal serotypes escaping immune pressure. To understand the basis for the declining incidence, we assessed the intrinsic capacity of pneumococcal serotypes to cause OM independently and in polymicrobial infections involving nontypeable (NTHi) using samples obtained from middle ear fluid and nasopharyngeal cultures before PCV7/13 rollout. Data included samples from OM episodes (11,811) submitted for cultures during a 10-year prospective study in southern Israel and nasopharyngeal samples (1,588) from unvaccinated asymptomatic children in the same population. We compared data representing pneumococcal serotype diversity across carriage and disease isolates with and without NTHi coisolation. We also measured associations between the pneumococcal phenotype and the rate of progression from colonization to OM in the presence and absence of NTHi. Whereas pneumococcal serotype diversity was lower in single-species OM than in single-species colonization, levels of serotype diversity did not differ significantly between colonization and OM in mixed-species episodes. Serotypes differed roughly 100-fold in progression rates, and those differences were attenuated in polymicrobial episodes. Vaccine serotype pneumococci had higher rates of progression than nonvaccine serotypes. While serotype invasiveness was a weak predictor of the OM progression rate, efficient capsular metabolic properties-traditionally thought to serve as an advantage in colonization-predicted an enhanced rate of progression to complex OM. The lower capacity of nonvaccine serotypes to cause OM may partially account for reductions in all-cause OM incidence despite serotype replacement in carriage following rollout of PCVs.

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“…An interesting finding was the high proportion of bacterial co‐detections, compared to those based on marginal prevalences, in children sharing the same risk factors . Bacteria may act synergistically in the nasopharynx, although competition can also occur . PCR detection is probably much more efficient at detecting multiple bacteria than conventional cultures.…”

Section: Discussionmentioning

confidence: 99%

Nasal swab bacteriology by PCR during the first 24‐months of life: A prospective birth cohort study

Palmu

Ware

Lambert

et al. 2019

Pediatric Pulmonology

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Background Most respiratory bacterial carriage studies in children are based on cross‐sectional samples or longitudinal studies with infrequent sampling points. The prospective Observational Research in Childhood Infectious Diseases birth cohort study intensively evaluated the community‐based epidemiology of respiratory viruses and bacteria during the first 2‐years of life. Here we report the bacteriologic findings. Methods Pregnant women in Brisbane, Australia were recruited between September 2010 and October 2012, and their healthy newborn children were followed for the first 2‐years of life. Parents kept a daily symptom diary for the study child, collected a weekly anterior nose swab and completed an illness burden diary when their child met pre‐defined illness criteria. Specimens were tested for respiratory bacteria by real‐time polymerase chain reaction (PCR) assays and those containing human genomic DNA, deemed as high‐quality, were analyzed. Results Altogether 8100 high‐quality nasal swab specimens from 158 enrolled children were analyzed. Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae were detected in 42.4%, 38.9%, and 14.8% of these samples, respectively. Concomitant detection of bacteria was common. In contrast, Bordetella pertussis, B. parapertussis, Mycoplasma pneumoniae, Chlamydia pneumoniae, and Simkania negevensis were rarely identified. The prevalence of the three major bacteria was higher with increasing age and in the winter and spring months. Siblings and childcare attendance were the other risk factors identified. Conclusions We confirmed the feasibility of frequent nasal swabbing by parents for studying bacterial colonization. PCR detected the major respiratory tract bacteria with expected high frequencies, but atypical bacteria were found rarely in this cohort.

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Density, Serotype Diversity, and Fitness ofStreptococcus pneumoniaein Upper Respiratory Tract Cocolonization With NontypeableHaemophilus influenzae

Cited by 26 publications

References 45 publications

Pneumococcal carriage, density, and co-colonization dynamics: A longitudinal study in Indonesian infants

Pneumococcal carriage, density, and co-colonization dynamics: A longitudinal study in Indonesian infants

Pneumococcal Phenotype and Interaction with Nontypeable Haemophilus influenzae as Determinants of Otitis Media Progression

Nasal swab bacteriology by PCR during the first 24‐months of life: A prospective birth cohort study

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