Bordetella pertussis clones identified by multilocus variable-number tandem-repeat analysis.

Area of Science:

• Microbiology
• Genetics
• Epidemiology

Background:

• Bordetella pertussis causes whooping cough, a significant public health concern.
• Pertussis outbreaks have been observed despite high vaccination rates, suggesting potential pathogen evolution.
• Understanding genetic diversity is crucial for effective pertussis control and vaccine development.

Purpose of the Study:

• To analyze the genetic diversity of Bordetella pertussis isolates over a 40-year period.
• To identify predominant strains and track their evolution.
• To investigate potential associations between genetic changes and acellular pertussis vaccines.

Main Methods:

• Multilocus variable-number tandem-repeat analysis (MLVA) was performed on 316 Bordetella pertussis isolates.
• Isolates were collected over 40 years from Australia and three other continents.
• Genes encoding acellular vaccine antigens were typed.

Main Results:

• A total of 66 distinct MLVA types (MTs) were identified.
• Six predominant MTs were identified globally.
• Two MTs prevalent in Australia exhibited genetic changes in genes encoding acellular vaccine antigens, suggesting potential vaccine-driven evolution.

Conclusions:

• MLVA is effective in characterizing the genetic diversity of Bordetella pertussis.
• The study identified key circulating strains and highlighted potential adaptive evolution in response to vaccination.
• Further research is warranted to confirm the impact of vaccine pressure on Bordetella pertussis evolution.