Medium distinguishes between Campylobacter species

A newly developed culture medium provides a simpler way to distinguish between Campylobacter species, according to scientists.

The new culture medium, called Campy-Cefex, is specifically designed to detect and differentiate C. jejuni and C. coli mixtures of food-contaminating microbes in poultry. With the increasing amount of testing required at processing plants, the medium might help managers looking for faster, more accurate means of ensuring their products are safe. Campy-Cefex selects for Campylobacter among competing flora in a sample, cultivating colonies that resemble tiny water droplets. From these, microbiologists can estimate the level of Campylobacter contamination in the sample. The two bacteria are important causes of foodborne illness. The culture medium was developed by Agricultural Research Service (ARS) microbiologist Norman Stern, along with researchers Boleslaw Wojton and Kris Kwiatek at the Veterinary Research Institute in Pulawy, Poland. They worked cooperatively to characterise Campylobacter contamination in poultry. Previous media for detection of Campylobacter relied upon the use of new antibiotics that were unavailable in Poland, ARS stated. In developing the medium, Stern used only cycloheximide and cefoperazone. The two compounds provided to be more efficient than the new ones on the market, not only for growing Campylobacter in a culture, but also for repressing the growth of most other microorganisms, ARS stated. The additional antibiotics previously employed with other Campylobacter media were not needed, the scientists concluded. A patent for the Campy-Cefex culture medium was awarded in 1999 to Stern, with Wojton and Kwiatek listed as co-inventors. The scientists have now licenced Becton Dickinson and Company and Neogen Corporation to start producing the medium for the market. Last year the European Food Safety Authority (EFSA) reported that Campylobacteriosis had overtaken salmonellosis as the most reported animal infection transmitted to humans in the EU. The findings are influencing current European food safety policy decisions, with an increased focus on reducing Campylobacteriosis. In 2005, reported cases of campylobacter in humans increased 7.8 per cent against the previous year rising to an incidence rate of 51.6 per 100,000 and a total of 197,363 recorded cases. Salmonella, campylobacter, and viruses were the most important causes of reported foodborne outbreaks in 2005. Egg and bakery products were the most common sources ofSalmonella outbreaks, whereas broiler meat was an important source for both salmonella and campylobacter outbreaks. As in 2004, the primary source of campylobacter infections in 2005 was linked to fresh poultry with up to 66 per cent of some samples testing positive. Salmonella infections, while still remaining a serious threat to human heath and very much in the public consciousness, fell by 9.5 per cent in 2005 to an incidence rate of 38.2 cases per 100,000, with a total 176,395 reported cases.