EUpertstrain 4 Study of Bordetella Pertussis Isolates

Study Overview
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Brief Summary
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This study focus on the genetic changes of B. pertussis clinical isolates. For this panels of B. pertussis isolates has been collected during four periods in different European countries.

Detailed Description
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B. pertussis is considered as a monomorphic pathogen. However, genetic changes have been observed in several antigens (pertussis toxin, pertactin, filamentous haemagglutinin and fimbriae) included in the current acellular pertussis vaccines between vaccine strains and circulating isolates. To study genetic changes in the B. pertussis populations in Europe, four distinct panels have been collected: EUpert I in 1999-2001 including 102 isolates, EUpert II in 2004-2005 including 154 isolates, EUpert III in 2007-2009 including 140 isolates and EUpert IV in 2012-2015 including 265 isolates. Selection criteria have remained unchanged for all four collections, which enables the opportunity to study changes in B. pertussis populations during the last 15 years.

Official Title
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EUpertstrain 4 Study of Bordetella Pertussis Isolates

Conditions
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Bordetella Pertussis, Whooping Cough

Intervention / Treatment
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* Other: Strain isolation from the nasopharynx


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: B. pertussis clinical isolates should be collected from subjects from different regions and be epidemiologically unrelated. An equal number of isolates from vaccinated and unvaccinated subjects should be collected. Optimally, the isolates are preferred to be selected from individuals less than 5 years of age. For countries with large numbers of isolates in their collections, isolates should be randomly selected according to criteria above. Exclusion Criteria: There is no strict exclusion criteria for this study
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Strain isolation from the nasopharynx<br>A group of culture positive whooping cough patients. | Other: Strain isolation from the nasopharynx<br>* B. pertussis strains has been collected from the nasopharynx of the patients during the clinical visit<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vaccine antigen deficient (VAD) B. pertussis clinical isolates | We screened a panel of 265 B. pertussis clinical isolates collected from 9 European countries. We used previously developed ELISA to measure the antigen expression of pertussis toxin (PT), filamentous haemagglutinin (FHA), pertactin (PRN) and fimbriae 2&3 (Fim2&3). In addition, we used sequencing to further characterize the pertactin gene of the bacteria. | 24 months | 
| Study of genetic changes in the B. pertussis genomic content measured by specific molecular methods | We studied genetic changes in the main virulence genes of B. pertussis. We genotyped pertussis toxin promoter (ptxP), pertactin (PRN), fimbriae3 (Fim3) and pertussis toxin subunit A (ptxA). Serotyping of Fimbriae (Fim), Pulsed-Field Gel Electrophoresis (PFGE) and Multiple-Locus Variable number tandem repeat Analysis (MLVA) were used for further genomic analysis. | 24 months | 
| Association between vaccine antigen deficient (VAD) B. pertussis clinical isolates and their association to the introduction of acellular pertussis vaccination (ACV) | We studied the association between the frequency of VAD B. pertussis clinical isolates and their association to the introduction of ACV. Data of vaccination schedules by country and number of VAD isolates were collected and compared. | 24 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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B. pertussis, Acellular vaccination, Strain variation