Campylobacters are the most common cause of bacterial food poisoning in the
UK and are prominent in many other countries worldwide. Sources that have
acted as vehicles of infection in many outbreaks include milk, water and po
ultry, and these may contain campylobacter cells that are sublethally injur
ed and not detected by routine laboratory techniques. Current culture media
contain antibiotics to suppress competing flora, and injured campylobacter
cells are more sensitive to the antibiotics used and may not grow in these
selective media. Therefore, the use of selective broth as the primary cult
ure medium may reduce the isolation rate from samples containing injured ce
lls. To examine this, various experiments were carried out using naturally
contaminated river water and fresh chicken samples. In these samples, campy
lobacter cells showed varying degrees of sublethal injury, with the greates
t found in water. A delay of four to eight hours before adding antibiotics
to broth significantly increased isolation rate, compared with direct cultu
re in selective broth. With chicken, however, significantly better results
were obtained with selective broth as the primary medium.