Comparison of sensitivity of a Campy-Cefex dilution method and PCR in detecting Campylobacter in broilers

The aim of the study was to compare the sensitivity of a Campy-Cefex dilution method and PCR for detecting Campylobacter in broilers and to see if any traces of the bacteria were to be found by these methods during winter when the bacteria is not detectable by conventional microbiological methods. The results of our studies done in 2004 and 2005 were compared with data from 2001-2003 soon after a national surveillance of Campylobacter spp. in broilers was initiated. Faecal samples from 607 broiler flocks were pooled, 10 samples per pool, and diluted in saline for the Campy-Cefex direct plating dilution method and PCR. The PCR amplification was performed in a Peltier Thermal Cycler and the primers used were C412F and C1288R. A total of 742 pooled caecal samples were collected at slaughter. Samples from each pool of 40 caeca were diluted in saline for the Campy-Cefex direct plating dilution method. The PCR method proved to be more sensitive than the Campy-Cefex method but still did not detect any traces of Campylobacter during winter. A comparison of the results from 2001-2003 with the results from 2004-2005 indicates that the percentage of positive flocks had diminished. The study underlines the importance of using sensitive methods for detecting Campylobacter spp. in order to minimize the risk of human exposure. The finding that the sensitive PCR method was not able to detect Campylobacter during winter suggests that the seasonal pattern of campylobacteriosis is due to a new vector in the spring which carries the bacterium.