Isolates used to create spiked samples.

<p>¹Isolates were kindly provided by Prof. Samir Saha (Bangladesh), Assoc. Prof Fiona Russell (Fiji), Dr. Peter Adrian and Prof. Shabir Madhi (South Africa), and Prof. Kate O’Brien (United States).</p><p>²Site of isolation not known.</p><p>Isolates used to create spiked samples.</p

Sensitivity and PPV of the five methods testing the 260 field samples.

<p>The point estimates and 95% CIs for sensitivity (A) and PPV (B) are depicted. The sensitivity of method 4 is higher than those of the other methods.</p

Serotype distribution in field samples.

<p>A total of 307 serotypeable pneumococci (representing 49 serotypes) were identified in 260 nasopharyngeal swab samples collected from children in six countries. The 26 most common serotypes are shown here, with the remaining 23 serotypes identified combined as “other”.</p

Relationship between pneumococcal carriage densities and IL-17A levels (A) Pneumococcal nasopharyngeal (NP) carriage densities in all 65 children from Fiji was measured by qPCR.

<p>IL-17A was measured by multiplex bead array. One child was removed from the analysis as an outlier (Carriage density = 1.65x10⁵ CFU/ml, IL-17A = 1710pg/ml). The correlation with the outlier was R = -0.19, p = 0.126. Correlation between IL-17A and children with low pneumococcal carriage density (B; N = 27) or children with high pneumococcal carriage density (C; N = 27). The Spearman test was used to correlate children with pneumococcal carriage density and IL-17A levels.</p

Cytokine profiles in PBMCs from children with low and high pneumococcal carriage densities.

<p>(A) Relationship between Th17 and Tregs under normal immune homeostasis and under different diseases contexts (Figure taken from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0129199#pone.0129199.ref036" target="_blank">36</a>]). Th17 cells are the major source of IL-17A which plays a protective role against pneumococcal infection, fungal infection and extracellular bacteria such as <i>Staphylococcus aureus</i>. However, in autoimmune and chronic inflammatory diseases such as Multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease and psoriasis, IL-17A is known to be pathogenic (Adapted from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0129199#pone.0129199.ref012" target="_blank">12</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0129199#pone.0129199.ref037" target="_blank">37</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0129199#pone.0129199.ref038" target="_blank">38</a>]). Comparison of (B) IL-23 and IL-22 (Th17) (C) TGF-β and IL-10 (Tregs) (D) IL-6, IFN-γ and TNF-α (pro-inflammatory cytokines) levels between children with high or low pneumococcal carriage densities. Bars represent mean ± SEM. Statistical comparisons were done using an unpaired Student’s t test.</p

IL-17A levels in children with high and low pneumococcal carriage densities.

<p>(A) Carriage density >8.21 x 10⁵ CFU/ml was defined as a ‘high’ carrier and <1.67 x 10⁵ CFU/ml was defined as a ‘low’ carrier. Scatter plots show the median <b>±</b> interquartile range for children with high carriage (N = 27) and low carriage (N = 27). Statistical comparisons were done using Mann-Whitney U test. (B) IL-17A levels in PBMC supernatants from children in Fiji with high (N = 27) or low (N = 27) pneumococcal carriage densities as well as children that did not carry pneumococcus (N = 29). Bars represent mean ± SEM. Statistical comparisons were done using an unpaired Student’s t test.</p

Correlation between IL-17A and other Th17 cytokines IL-22 (A) and IL-23 (B) levels in PBMCs from children with high and low pneumococcal carriage density (N = 46).

<p>The Spearman test was used to correlate the cytokine levels.</p

Nasopharyngeal carriage prevalence (%) of <i>S</i>. <i>pneumoniae</i>, <i>H</i>. <i>influenzae</i>, <i>M</i>. <i>catarrhalis</i>, and <i>S</i>. <i>aureus</i> in Indonesian children aged 12–24 months.

<p>Results are shown by region (Bandung, Padang, and Lombok). Error bars represent 95%CI.</p