EUpertstrain 4 Study of Bordetella Pertussis Isolates

Completed

• Conditions: Bordetella Pertussis, Whooping Cough
• Interventions: Other: Strain isolation from the nasopharynx

• Registration Number: NCT03197597
• Lead Sponsor: University of Turku

Brief Summary

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

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.

Study Timeline

• Study Start: 2015-10-12
• Primary Completion: 2016-12-31
• Study Completion: 2016-12-31
• Status Verified: 2017-06
• Study First Submitted: 2017-06-13
• Study First Submitted QC: 2017-06-22
• Last Update Submitted: 2017-06-22
• Study First Posted: 2017-06-23
• Last Update Posted: 2017-06-23

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 265

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

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Strain isolation from the nasopharynx	Strain isolation from the nasopharynx	A group of culture positive whooping cough patients.

Primary Outcome Measures

Name	Time	Method
Study of genetic changes in the B. pertussis genomic content measured by specific molecular methods	24 months	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.
Vaccine antigen deficient (VAD) B. pertussis clinical isolates	24 months	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.
Association between vaccine antigen deficient (VAD) B. pertussis clinical isolates and their association to the introduction of acellular pertussis vaccination (ACV)	24 months	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.

Trial Locations

Locations (1)

University of Turku; 🇫🇮 Turku, Finland