Antimicrobial susceptibility testing of bovine and porcine <i>Pasteurellaceae</i> —essential requirements and pitfalls

ABSTRACT With increasing resistance rates among bovine and porcine bacterial pathogens, antimicrobial susceptibility testing (AST) has become essential for guiding the selection of effective antimicrobial agents in veterinary practice. In particular, Pasteurellaceae involved in respiratory tract infections of cattle and pigs have become an important focus of such testing. In this article, essential requirements for AST of bovine and porcine Pasteurellaceae are presented with regard to the performance and interpretation of the tests. Particular emphasis is placed on the testing conditions, the use of recommended quality controls, and the application of correct interpretive criteria to classify the isolates as susceptible or resistant. The information presented aims to prevent errors and provide guidance for correct AST performance in a standardized and harmonized way.