Low prevalence of antimicrobial resistant organisms (methicillin resistant Staphylococcus aureus, extended beta‐lactamase producing Enterobacteriaceae, and vancomycin resistant enterococci) in bulk tank milk in New South Wales, Australia

Abstract

ObjectiveEstimate the presence of methicillin resistant Staphylococcus aureus (MRSA), extended beta‐lactamase (ESBL) producing Enterobacteriaceae, and vancomycin resistant enterococci (VRE) in bulk tank milk in dairy herds in New South Wales (NSW), Australia.MethodsBulk tank milk samples (n = 80) were collected from dairy farms (n = 40, i.e. 2 per farm) in NSW during 2021. Bacteria were cultured using selective chromogenic indicator media with isolate identity confirmed using biochemical testing, Gram stain, and MALDI‐TOF mass spectroscopy. Antimicrobial resistance (AMR) was confirmed using antibiotic disk diffusion.ResultsNo samples tested positive to the targeted AMR organisms.ConclusionThe prevalence of MRSA, ESBL‐producing Enterobacteriaceae, and VRE is low in NSW dairy herds.