High-throughput QIAxcel Based Subtyping: Application to Enhanced Epidemiologic Surveillance of Campylobacter jejuni

Campylobacter-related gastroenteritis is the most common bacterial foodborne diarrheal disease worldwide. Each year up to 1% of the population in developed nations will be afflicted by campylobacteriosis, primarily incited by Campylobacter jejuni. In developing nations, the high prevalence of Campylobacter infections among infants under two years of age is of particular public health concern.

Molecular subtyping methods differentiating microbial isolates below species and subspecies levels have been instrumental in furthering our understanding of the epidemiology, population genetics, and ecology of different microbial pathogens. Multi-Locus Sequence Typing (MLST), the gold standard for C. jejuni subtyping, has provided significant insight into campylobacteriosis molecular epidemiology, but substantial gaps still exist in our understanding of this pathogen. Many campylobacteriosis cases can be attributed to ingestion of contaminated poultry products, but the source of exposure for a significant proportion of cases remains unknown. This is further complicated by the near ubiquitous nature of Campylobacter in wild and domestic animal populations and the possible role of contaminated surface waters. Critically, none of the currently existing subtyping methods for C. jejuni are optimal for case cluster and outbreak detection.

In this seminar, the development of Comparative Genomic Fingerprinting (CGF), an advanced method for C. jejuni subtyping developed in our laboratory, will be described. This method generates data that are highly concordant with MLST but also provides additional discriminatory power required for a range of epidemiologic applications, including case cluster detection. Integration of the QIAxcel Advanced platform into the CGF workflow and the resulting high-throughput and low-cost subtyping assay for deployment in the context of a national laboratory surveillance system will also be discussed. The development of a national network in support of advanced epidemiological studies of Campylobacter represents a first step in a cohesive mitigation strategy for the prevention and control of campylobacteriosis.

Dr. Eduardo Taboada

Dr. Eduardo Taboada has studied various aspects of Campylobacter genomics for the past decade, first at National Research Council of Canada, where he worked on examining the role of genomic variability and gene regulation on the virulence of Campylobacter jejuni. Since joining the Laboratory for Foodborne Zoonoses in the Public Health Agency of Canada as a research scientist in 2006, he has established a research program on comparative genomics focused on the application of genomics-based approaches towards investigating the molecular epidemiology of Campylobacter and other enteric pathogens as part of an emerging genomic epidemiology paradigm. A current priority is the development of bioinformatics tools for the analysis and visualization of genomics data and their integration with clinical and epidemiological data towards identifying subtypes that pose an increased risk to human health.