[Trends of antibiotic use and resistance in livestock from 2014 to 2024 using the example of fattening turkeys and broiler chickens as well as the effects on humans].

INTRODUCTION: In livestock, antibiotics are often used to treat groups of animals, such as poultry. With the 16th amendment of the Medicinal Products Act, the antibiotic minimization concept was introduced in Germany in 2014. As a result, treatment frequencies were reduced in many animal populations. The aim of this study is to present the development of antibiotic use and resistance in the populations of fattening turkeys and broiler chickens as well as the effects on the resistance situation in human medicine.

METHODS: The treatment frequencies in fattening turkeys and broiler chickens for 2014-2024 were compared with data from zoonosis monitoring, namely the resistance rates of Escherichia (E.) coli, Campylobacter (C.) coli, and C. jejuni against antibiotics, and contextualized in relation to the human resistance situation based on Joint Interagency Antimicrobial Consumption and Resistance Analysis (JIACRA) work.

RESULTS: The treatment frequency decreased from 60.9 to 45.6 days (-26%) in fattening turkeys but increased from 41.5 to 45.9 days (+11%) in broiler chickens. The use of critically important antibiotics has been greatly reduced in both populations. In fattening turkeys, the resistance rates of E. coli decreased significantly, whereas in broiler chickens, some increases were observed. Resistance of C. jejuni to ciprofloxacin increased despite reduced antibiotic use. The JIACRA reports show that the development of resistance in E. coli from animals and humans is associated with the use of antibiotics in the respective population, whereas in Campylobacter there is a direct relationship between animal and human resistance rates.

DISCUSSION: The results illustrate the need for targeted measures to further reduce the use of antibiotics and point to complex dynamics in resistance development.