In vitro antimicrobial resistance profiles of Streptococcus uberis, Lactococcus spp., and Enterococcus spp. from quarter milk samples of cows between 2015 and 2019 in Southern Germany

The objective was to describe and compare antimicrobial resistance patters of esculin-hydrolyzing streptococci streptococcal-like organisms (Streptococcus uberis, Enterococcus faecium, faecalis, Lactococcus garvieae, lactis) from routine diagnostic samples the udder health laboratory Bavarian Animal Health Services between 2015 2019. All Services, that were tested with a standard microbroth dilution, eligible be included in this retrospective case series. A California Mastitis Test result available for all samples. Most Strep. uberis L. lactis susceptible antibiotics tested. faecium had consistently highest minimum inhibitory concentration required inhibit growth 90% isolates. patterns garvieae positioned enterococci lactis. various pathogens tended decrease over 5-yr period. Regardless pathogen, isolates clinical cases less likely express vitro than healthy or subclinical cases. Streptococcus showed hardly any antibiotic groups. Penicillin should remain first-choice therapy spp. However, success treatment enterococcal infections seems questionable.