GLORIA

GEOMAR Library Ocean Research Information Access

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    In: Frontiers in Microbiology, Frontiers Media SA, Vol. 14 ( 2023-4-17)
    Abstract: Despite strong historical records on the accuracy of saliva testing, oral fluids are considered poorly suited for pneumococcal carriage detection. We evaluated an approach for carriage surveillance and vaccine studies that increases the sensitivity and specificity of pneumococcus and pneumococcal serotype detection in saliva samples. Methods Quantitative PCR (qPCR)-based methods were applied to detect pneumococcus and pneumococcal serotypes in 971 saliva samples collected from 653 toddlers and 318 adults. Results were compared with culture-based and qPCR-based detection in nasopharyngeal samples collected from children and in nasopharyngeal and oropharyngeal samples collected from adults. Optimal C q cut-offs for positivity in qPCRs were determined via receiver operating characteristic curve analysis and accuracy of different approaches was assessed using a composite reference for pneumococcal and for serotype carriage based on isolation of live pneumococcus from the person or positivity of saliva samples determined with qPCR. To evaluate the inter-laboratory reproducibility of the method, 229 culture-enriched samples were tested independently in the second center. Results In total, 51.5% of saliva samples from children and 31.8% of saliva samples from adults were positive for pneumococcus. Detection of pneumococcus by qPCR in culture-enriched saliva exhibited enhanced sensitivity and higher agreement with a composite reference compared to diagnostic culture of nasopharyngeal samples in children (Cohen’s κ: 0.69–0.79 vs. 0.61–0.73) and in adults (κ: 0.84–0.95 vs. 0.04–0.33) and culture of oropharyngeal samples in adults (κ: 0.84–0.95 vs. −0.12–0.19). Similarly, detection of serotypes with qPCR in culture-enriched saliva exhibited enhanced sensitivity and higher agreement with a composite reference compared to nasopharyngeal culture in children (κ: 0.73–0.82 vs. 0.61–0.73) and adults (κ: 0.90–0.96 vs. 0.00–0.30) and oropharyngeal culture in adults (κ: 0.90–0.96 vs. −0.13 to 0.30). However, results of qPCRs targeting serotype 4, 5, and 17F and serogroups 9, 12, and 35 were excluded due to assays’ lack of specificity. We observed excellent quantitative agreement for qPCR-based detection of pneumococcus between laboratories. After exclusion of serotype/serogroup-specific assays with insufficient specificity, moderate agreement (κ 0.68, 95% CI 0.58–0.77) was observed. Conclusion Molecular testing of culture-enriched saliva samples improves the sensitivity of overall surveillance of pneumococcal carriage in children and adults, but limitations of qPCR-based approaches for pneumococcal serotypes carriage detection should be considered.
    Type of Medium: Online Resource
    ISSN: 1664-302X
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2023
    detail.hit.zdb_id: 2587354-4
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    In: Clinical Infectious Diseases, Oxford University Press (OUP), Vol. 73, No. 9 ( 2021-11-02), p. e2680-e2689
    Abstract: In older adults, pneumococcal disease is strongly associated with respiratory viral infections, but the impact of viruses on Streptococcus pneumoniae carriage prevalence and load remains poorly understood. Here, we investigated the effects of influenza-like illness (ILI) on pneumococcal carriage in community-dwelling older adults. Methods We investigated the presence of pneumococcal DNA in saliva samples collected in the 2014/2015 influenza season from 232 individuals aged ≥60 years at ILI onset, followed by sampling 2–3 weeks and 7–9 weeks after the first sample. We also sampled 194 age-matched controls twice 2–3 weeks apart. Pneumococcal DNA was detected with quantitative polymerase chain reaction assays targeting the piaB and lytA genes in raw and in culture-enriched saliva. Bacterial and pneumococcal abundances were determined in raw saliva with 16S and piaB quantification. Results The prevalence of pneumococcus-positive samples was highest at onset of ILI (42/232 [18%]) and lowest among controls (26/194 [13%] and 22/194 [11%] at the first and second samplings, respectively), though these differences were not significant. Pneumococcal carriage was associated with exposure to young children (odds ratio [OR] , 2.71 [95% confidence interval {CI}, 1.51–5.02]; P  & lt; .001), and among asymptomatic controls with presence of rhinovirus infection (OR, 4.23 [95% CI, 1.16–14.22]; P  & lt; .05). When compared with carriers among controls, pneumococcal absolute abundances were significantly higher at onset of ILI (P  & lt; .01), and remained elevated beyond recovery from ILI (P  & lt; .05). Finally, pneumococcal abundances were highest in carriage events newly detected after ILI onset (estimated geometric mean, 1.21 × 10−5 [95% CI, 2.48 × 10−7 to 2.41 × 10−5], compared with preexisting carriage). Conclusions ILI exacerbates pneumococcal colonization of the airways in older adults, and this effect persists beyond recovery from ILI.
    Type of Medium: Online Resource
    ISSN: 1058-4838 , 1537-6591
    RVK:
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2021
    detail.hit.zdb_id: 2002229-3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    In: Vaccine, Elsevier BV, Vol. 41, No. 34 ( 2023-07), p. 4927-4932
    Type of Medium: Online Resource
    ISSN: 0264-410X
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2023
    detail.hit.zdb_id: 1468474-3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 11, No. 1 ( 2021-11-30)
    Abstract: Carriage of Neisseria meningitidis is an accepted endpoint in monitoring meningococcal vaccines effects. We have assessed N. meningitidis and vaccine-type genogroup carriage prevalence in college students at the time of MenACWY vaccine introduction in the Netherlands, and evaluated the feasibility of saliva sampling for the surveillance of carriage. For this, paired saliva and oropharyngeal samples collected from 299 students were cultured for meningococcus. The DNA extracted from all bacterial growth was subjected to qPCRs quantifying meningococcal and genogroup-specific genes presence. Samples negative by culture yet positive for qPCR were cultured again for meningococcus. Altogether 74 (25%) of students were identified as meningococcal carrier by any method. Sixty-one students (20%) were identified as carriers with qPCR. The difference between number of qPCR-positive oropharyngeal (n = 59) and saliva (n = 52) samples was not significant (McNemar’s test, p  = 0.07). Meningococci were cultured from 72 students (24%), with a significantly higher ( p   〈  0.001) number of oropharyngeal (n = 70) compared with saliva (n = 54) samples. The prevalence of genogroups A, B, C, W, and Y was none, 9%, 1%, 1% and 6%, respectively, and 8% of students carried MenACWY vaccine-type genogroup meningococci. Saliva is easy to collect and when combined with qPCR detection can be considered for meningococcal carriage studies.
    Type of Medium: Online Resource
    ISSN: 2045-2322
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2021
    detail.hit.zdb_id: 2615211-3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    In: ISME Communications, Oxford University Press (OUP)
    Abstract: Pneumococcal carriage studies have suggested that pneumococcal colonization in adults is largely limited to the oral cavity and oropharynx. In this study we used total abundance-based β-diversity (dissimilarity) and β-diversity components to characterize age-related differences in pneumococcal serotype composition of respiratory samples. qPCR was applied to detect pneumococcal serotypes in nasopharyngeal samples collected from 946 toddlers and 602 adults, saliva samples collected from a subset of 653 toddlers, and saliva and oropharyngeal samples collected from a subset of 318 adults. Bacterial culture rates from nasopharyngeal samples were used to characterize age-related differences in rates of colonizing bacteria. Dissimilarity in pneumococcal serotype composition was low among saliva and nasopharyngeal samples from children. In contrast, respiratory samples from adults exhibited high serotype dissimilarity, which predominantly consisted of abundance gradients and was associated with reduced nasopharyngeal colonization. Age-related serotype dissimilarity was high among nasopharyngeal samples and relatively low for saliva samples. Reduced nasopharyngeal colonization by pneumococcal serotypes coincided with significantly reduced Moraxella catarrhalis and Haemophilus influenzae and increased Staphylococcus aureus nasopharyngeal colonization rates among adults. Findings from this study suggest that within-host environmental conditions, utilized in the upper airways by pneumococcus and other bacteria, undergo age-related changes. It may result in a host-driven ecological succession of bacterial species colonizing the nasopharynx and lead to competitive exclusion of pneumococcus from the nasopharynx but not from the oral habitat. This explains the poor performance of nasopharyngeal samples for pneumococcal carriage among adults and indicates that in adults saliva more accurately represents the epidemiology of pneumococcal carriage than nasopharyngeal samples.
    Type of Medium: Online Resource
    ISSN: 2730-6151
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2024
    detail.hit.zdb_id: 3041786-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...