Tel.+49 30 8385 1845 Fax.+49 30 83845 1863
Background and objectives: Previous studies showed that Enterobacteriaceae producing extended-spectrum (ESBL) or AmpC beta-lactamases are occurring in herds on broiler farms. Even one day old chicks were tested positive for these resistant bacteria suggesting an early entry within the broiler production chain. In our study we, therefore, surveyed seven parent broiler flocks and their chicks along the broiler fattening period.
Materials and methods: First we investigated faecal and environmental samples from the parent flocks. Several samples from the environment of the hatchery as well as from the eggs where taken. At least the hatched chicks were investigated three times during the fattening period. We isolated suspicious enterobacteria from the samples and analysed their species and the ESBL-/AmpC genes.
Results: From six out of seven flocks we isolated ESBL-/AmpC producing Enterobacteria from the chicks during the fattening period which in nearly all cases differ genetically from those we found in their parent flocks. However, we could provide evidence for a pseudo-vertical transfer from a parent flock to the hatchery via contaminated egg surfaces.
Conclusion: An exclusively vertical transfer of ESBL-/AmpC producingenterobacteria along the broiler production chain seems to be not very likely. The management of the hatchery as well as the cleaning and disinfection procedures on the fattening farm also have an impact on the occurrence of ESBL-/AmpC producing Enterobacteria.