Nasal colonisation with pneumococcal bacteria Infections and Infestations Streptococcus pneumoniae infection
Conditions
Interventions
All volunteers will have screening samples taken including nasal wash, nasal cell samples, nasosorption and blood samples. A clinical examination will be performed during the screen visit and a pregna
Sponsors
Royal Liverpool and Broadgreen University Hospital Trust
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: 1. Has capacity to give informed consent 2. Aged 18-50 years (ages chosen to minimise the risk of pneumococcal infection) 3. Speaks fluent English
Exclusion criteria
Exclusion criteria: 1. Currently involved in another study unless observational or in follow-up phase (non-interventional) 2. Are in close contact with at risk individuals (children under 5 years, immunosuppressed adults, elderly, chronic ill health) – to minimise risk of pneumococcal transmission 3. Current regular smoker (smokes daily) - to minimise risk of pneumococcal disease 4. Significant smoking history [defined as someone who has previously smoked more than 20 cigarettes per day for 10 years or the equivalent (>10 pack-years)] – to minimise risk of pneumococcal disease 5. Asthma (on regular medication) or respiratory disease – to minimise risk of pneumococcal disease 6. Pregnant - to minimise the risk of pneumococcal disease 7. On medication that may affect the immune system in any way e.g. steroids, steroid nasal spray 8. On medication that affects inflammation e.g. aspirin 9. On medication that affects clotting of blood e.g. dipyridamole or warfarin 10. Been involved in a clinical trial involving EHPC and bacterial inoculation over the last 3 years 11. Unable to give fully informed consent 12. Current acute severe febrile illness - to avoid inoculation in participants that may have current infection.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The principle objective is to evaluate if repeated mucosal sampling will obtain sufficient tissue for immunological assessment. Nasal cell yield will be measured using the flow cytometer to count the cell populations from the nasal cell samples taken at baseline, day 2, 7, 9 and 14 post-inoculation. | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. To evaluate the effect of repeated sampling of the nasal mucosa (lining of the nose) on the acquisition of pneumococcal colonisation. Pneumococcal colonisation is measured using microbiological techniques. The nasal wash pellet is plated onto agar plates and incubated for 48 hours using our previous published methods. Our previous studies have shown experimental colonisation rates of 40-60% following inoculation. The results of this study will be compared to previous healthy volunteer studies involving inoculation with 6B pneumococcus. 2. To evaluate if repeated mucosal sampling affects colonisation density and duration compared to previous EHPC studies. Pneumococcal colonies are counted from diluted nasal wash by plating the pellet using a Miles and Mizra technique. This is performed at baseline and day 2, 7, 9 and 14 post inoculation. The duration of colonisation is classed as the final timepoint at which pneumococcal bacteria is identified using classical microbiolgical techniques. The density and duration from this study will be compared to results from previous EHPC studies following inoculation of healthy volunteers to determine if the repeated nasal sampling technique has reduced the acquisition rates. 3. To evaluate participant comfort level following repeated mucosal sampling. Participants were asked to complete a Likert-type questionnaire to rate the level of comfort experienced with each mucosal sampling technique. 4. To evaluate the kinetics of nasal inflammatory response during pneumococcal colonisation. Cytokine levels are measured from the nasosorption sample using the Luminex machine. The levels measured on day 2, 7, 9 and 14 will be compared with the levels measured at baseline. 5. To evaluate if nasal sampling of cells causes a transient bacteraemia – patient safety issue. Paired blood cultures will be taken during each visit where nasal cell samples are taken. The first blood cultu | — |
Countries
United Kingdom
Outcome results
None listed