Detection of Campylobacter jejuni and Thermophilic Campylobacter spp. from Foods by Polymerase Chain Reaction

Campylobacter spp. is one of the most commonly reported bacterial causes of acute diarrheal disease in humans throughout the world (1 –3 ). The thermophilic Campylobacter jejuni, C. coli, C. lari , and C. upsaliensis are the most important species, with C. jejuni accounting for more than 95% of all the human Campylobacter infections (4 ,5 ). Poultry, raw milk, and water have been implicated as the major vehicles for Campylobacter infection (6 ,7 ), although other foods may also become a source of infection through cross-contamination from other food types, a food handler, or a work surface during food preparation (3 ). Because campylobacters have fastidious growth requirements and relatively inert biochemical characteristics, identification of these organisms and differentiation between species within the genus Campylobacter by cultural methods are time consuming and difficult (8 –10 ). The accuracy of some biochemical tests is also affected by bacterial inoculum size (11 ), which can be difficult to control. Additionally, Campylobacter cells are usually present in very low numbers and may become injured in foods and environmental water, and therefore become nonculturable (12 –15 ). Because of the foregoing, nucleic acid-based detection methods became alternatives for the detection of campylobacters.