Molecular Typing ofCampylobacter jejuni

Most published DNA-based techniques for typing bacterial pathogens have been applied to type Campylobacter jejuni. However, pulsed-field gel electrophoresis (PFGE), extended multilocus sequence typing (eMLST), and comparative genomic fingerprinting (CGF) are the techniques most currently employed for typing C. jejuni. PFGE is based on the restriction and migration profile of the whole genome and is an excellent technique for short-term epidemiological studies, such as outbreak studies of source identification, and is the technique used by PulseNet in the United States. eMLST is based on the sequence polymorphism of seven housekeeping genes and three antigenic gene targets, and is the technique of choice for studying population dynamics, evolution, and long-term global epidemiology. CGF, a low-cost binary typing scheme based on polymerase chain reaction amplification to determine the presence or absence of 40 genes, is useful for short- and long-term epidemiological studies and has currently been implemented in several national surveillance programs in Canada. These techniques may complement each other when a high level discriminatory power is needed.