Polymerase Chain Reaction Assay for the Detection of Viable Campylobacter Species from Potable and Untreated Environmental Water Samples

Abstract

Campylobacters are now widely recognised as the predominant cause of bacterial gastroenteritis worldwide (12). The consumption of contaminated foodstuffs, particularly poultry (11) and dairy products (10), and contact with untreated water supplies (9) constitute major sources of infection with these organisms. Rapid detection of campylobacters provides a potential means of monitoring and controlling the spread of disease outbreaks associated with this increasingly prevalent group of bacterial pathogens. As such, the polymerase chain reaction has been utilised for the rapid detection of campylobacters from dairy products (15) and water samples (5). However, given the widespread nature of campylobacters in the environment (2) and the sensitivity of the species to unfavourable environmental conditions, direct PCR detection methods risk detecting DNA from non-viable bacteria, thus leading to false positive results (4). The inclusion of a overnight enrichment stage in detection procedures significantly reduces the likelihood of detecting DNA from non-culturable bacteria (3) and also reduces the concentrations of substances which inhibit the PCR reaction, such as metal ions and humic acids, which are commonly found in water samples (1).