Population dynamics and antigenic drift of Bordetella pertussis following whole cell vaccine replacement, Barcelona, Spain, 1986-2015.

Among the factors associated with the resurgence of whooping cough, special emphasis has been given to pathogen adaptation after the introduction of the acellular vaccine (ACV). To assess the impact of the vaccine transition strategy from whole-cell vaccine (WCV) to ACV on population dynamics of Bordetella pertussis in Barcelona (Spain), we studied 339 isolates collected from 1986 to 2015 by PFGE and multi-locus variable-number tandem repeat analysis (MLVA). Additionally, allelic variants for the pertussis toxin and its promoter, pertactin, type 3 fimbriae and fimbrial serotyping were assessed to determine its antigenic drift. A shift was observed in the B. pertussis population as well as in its antigenic profile concurrently with the introduction of ACV in Barcelona. Four out of the five most prevalent PFGE profiles were replaced by new profiles following the ACV introduction. MLVA type 27 was the dominant genotype, and its frequency increased from 25% to 79.3% after WCV replacement. Antigen typing demonstrated the emergence of prn2, ptxP3, fim3-2 and a shift from the fimbriae 3 to the fimbriae 2 serotypes after the ACV introduction. Our findings support the presence of population and antigenic dynamic changes in B. pertussis likely driven by the introduction of ACV.

Emergence of Bordetella holmesii as a Causative Agent of Whooping Cough, Barcelona, Spain.

We describe the detection of Bordetella holmesii as a cause of whooping cough in Spain. Prevalence was 3.9% in 2015, doubling to 8.8% in 2016. This emergence raises concern regarding the contribution of B. holmesii to the reemergence of whooping cough and the effectiveness of the pertussis vaccine.

Molecular diagnosis in HAP/VAP.

PURPOSE OF REVIEW: This review describes recent findings related to molecular-based methods of potential application in the diagnosis of bacterial hospital-acquired pneumonia (HAP)/ventilator-associated pneumonia (VAP). It focuses on methods capable of providing organism identification and keys of bacterial resistance necessary in clinical and epidemiological management of patients and on their ability to provide quantitative results. RECENT FINDINGS: Significant advances have been made in recent years in the field of molecular diagnosis of bacterial pathogens. Real-time PCR, hybridization and mass spectrometry-based platforms dominate the scene. Some of the new technologies provide high sensitivity and specificity in the identification of single or multiple pathogens or a combination of etiological identification and antimicrobial resistance determinants in Staphylococcus aureus, nonfermenter Gram-negative bacilli and Enterobacteriaceae that are often associated with the cause of bacterial HAP/VAP in the late onset of the disease. In diagnosis made directly from clinical specimens and quantification of targets for bacterial load, some of them are promising. SUMMARY: Despite some limitations, current molecular diagnostic methods have a great potential to include bacterial targets useful in the identification of microorganisms and antimicrobial resistance, to analyze directly unprocessed samples and to obtain quantitative results in bacterial HAP/VAP, an entity of complex microbiological diagnosis due to the features of the pathogens commonly implicated.