Martine Denis, head of the National Reference Laboratory (NRL) for Campylobacter at ANSES, explains that veterinarians reported cases reminiscent of C. hepaticus symptoms, but traditional culture methods for Campylobacter did not work for this species, complicating its identification. In response, the Ploufragan-Plouzané-Niort laboratory coordinated a European project within the framework of the CoVetLab network, collaborating with NRLs from Sweden, Denmark, the Netherlands and the United Kingdom. After 18 months of research, a specific culture protocol and a PCR test were developed to isolate and confirm the presence of C. hepaticus.
Discovered in Australia and New Zealand in 2014, C. hepaticus mainly affects laying hens, causing a drop in egg production and mortality, with characteristic symptoms such as white spots on the liver. The PCR tests initially developed in Australia could detect the bacteria, but not determine whether it was alive or identify it genetically, hence the need to culture it.
The new C. hepaticus isolation protocol requires eight days of culture, compared to four for other Campylobacter species. Communicated to analysis laboratories, this protocol will provide a better understanding of the spread of the bacteria in livestock farms. By isolating the strains and characterizing their genetic profile, researchers will be able to trace the origin of the bacteria and determine whether it survives in the environment. This knowledge will help recommend preventive measures to farmers. The prevalence in France is not yet known, but it is likely to increase with global warming.
