Effect of capsule and pneumolysin on CXCL8 and IL-6 induction in human nasopharyngeal and bronchial epithelial cells.

<p>Detroit 562 nasopharyngeal epithelial cells (A and B) and bronchial epithelial cells (C and D) were assessed for CXCL8 (A and C) and IL-6 (B and D) release after exposure to wild type or mutant pneumococcal strains. All experiments were performed in triplicate at each of three CFU concentrations (1, 1.5 and 2 × 10⁶) and the results pooled for each strain. Note different scales of Y axes. Error bars indicate SEM. * indicates significant difference.</p

Capsule did not affect colonization of the nasopharynx but only nonencapsulated strains reached the lungs.

<p>Each symbol represents the CFU from the nasopharynx or lungs of an individual mouse on days 1, 3, 8 and 15 after intranasal inoculation. (No bacteria were detected at day 0 before any bacteria were administered.) Horizontal bars indicate means.</p

Effect of capsule and pneumolysin on CXCL8 homologue induction in the mouse nasopharynx.

<p>CXCL8 homologue (CXCL2/MIP-2) detected in nasopharyngeal homogenate of mice three days after exposure to wild type or mutant pneumococci expressed as a percentage of the value obtained with the wild type strain. Error bars indicate SEM. * indicates significant difference from value of the parent strain.</p

Synthesis of different magnetic carbon nanostructures by the pyrolysis of ferrocene at different sublimation temperatures

Various magnetic nanostructures such as Fe nanoparticles (Fe-NPs) adhering to single-walled carbon nanotubes, carbon-encapsulated Fe-NPs, Fe-NP decorated multi-walled carbon nanotubes (MWCNTs), and Fe-filled MWCNTs have been synthesized by the pyrolysis of pure ferrocene. It is found that the formation of the nanostructures can be selectively controlled by simply adjusting the sublimation temperature of ferrocene, while keeping all other experimental parameters unchanged. Magnetic characterization reveals that these nanostructures have an enhanced coercivity, higher than that of bulk Fe at room temperature. Based on the experimental results, the formation mechanism of the nanostructures is discussed in detail

Growth curves of strain 106.66 (serotype 6B) after replacing 6B capsule operon with operons of different serotypes.

<p>Growth of the wildtypes and nontypeable Janus mutant (A and C) and strain 106.66 with its capsule replaced by that of serotype 7F, 18C or 19F strains (B and D) was measured in MLM (A and B) and BHI+FCS medium (C and D). In MLM, growth of 106.66 was reduced and delayed by acquisition of other capsules. The effect was less for 19F than 7F or 18C reflecting the growth pattern of the wildtype donors. Graphs are representative of three independent experiments.</p

Metabolic burden of capsule was determined by incorporation of 3H-labelled glucose into the capsule.

<p>The fraction of labelled glucose taken up which was detected in the capsule was determined for wildtype strains and capsule switch mutants and the data pooled by serotype and normalized for colony forming units and thickness of capsule. Strains with 7F and 18C capsules incorporated a higher proportion of glucose into their capsules than the high colonization prevalence serotypes 6B and 19F in the MLM (p = 0.0068) but in the BHI+FCS medium there was no significant difference between the serotypes (p = 0.9493).</p

FITC-dextran exclusion assay.

<p>In BHI+FCS medium (A and B) strains 208.41 (serotype 7F) (A) and 106.66 (serotype 6B) (B) expressed similar amounts of capsule. In MLM (C and D) strain 106.66 (6B) (D) bacteria are bigger than strain 208.41 (7F) (C). All pictures are to the same scale, original magnification = 630 X. E) Mean area per bacterium (square pixels) was greater in BHI+FCS than in MEM (p<0.0001). In both media bacteria of 6B and 19F serotypes had thicker capsules than bacteria of 7F and 18C serotypes (p<0.0001). (n per serotype and medium category = 96–647).</p

Relative <i>cpsA</i> expression.

<p><i>CpsA</i> expression is displayed as the value for each isolate relative to that of the isolate with the lowest expression, after normalization using 16S RNA gene expression in BHI+FCS (B+F) medium and in MLM.</p

Electron microscopy showing polysaccharide capsules for measuring capsule thickness.

<p>In BHI+FCS medium (A and B) strains 208.41 (serotype 7F) (A) and 106.66 (serotype 6B) (B) expressed similar amounts of capsule. In MLM (C and D) thicker capsule can be distinguished for 106.66 (6B) (D) than 208.41 (7F) (C). * indicates capsule. Bar = 500 nm. E) Capsule thickness (nm) in wildtypes and capsule switch mutants in BHI+FCS (B+F) medium and in MLM. Capsules were thicker in BHI+FCS than in MEM (p<0.0001) for all serotypes except 6B. In MLM, the high prevalence serotypes 6B and 19F had thicker capsules than the low prevalence serotypes 7F and 18C (p<0.0001). (n per serotype and medium category = 25–118).</p

Quantification of capsule by HPLC.

<p>Cell bound capsular polysaccharides were released from wildtype strains and capsule switch mutants and after hydrolysis resulting in monosaccharides were quantified by reverse phase HPLC. The data was pooled by serotype.</p