Surveillance of circulatingBordetella pertussisstrains in Europe during 1998-2015.

Abstract

One reason for increased pertussis incidence is the adaptation of Bordetella pertussis to vaccine-induced immunity by modulating its genomic structure. This study, EUpert IV, includes 265 isolates collected from nine European countries during 2012 to 2015 (n=265) and compares the results to previous EUpert I-III studies (1998-2009). The analyses included genotyping, serotyping and pulsed-field gel electrophoresis (PFGE) and multi-locus variable-number tandem repeat analysis (MLVA). Genotyping results showed only small variation among the common virulence genes ofB. pertussisFrequencies of serotypes Fim2 and Fim3 varied among the four collections. Genomic analyses showed that MLVA type 27 increased to 80% between the periods of 1998-2001 and 2012-2015. Two PFGE profiles, BpSR3 (29.4%) and BpSR10 (27.2%), constituted more than 50% of the circulating isolates in the present collection. Our study indicates that the EuropeanB. pertussispopulation is changing more homogenous after the introduction of acellular pertussis vaccines.