phaidra.vetmeduni.ac.at o:1779 DOI 10.3390/antibiotics11020124 Analysis of Antimicrobial Use and the Presence of Antimicrobial-Resistant Bacteria on Austrian Dairy Farms— A Pilot Study The assumed link between high levels of antimicrobial use on farms and selection for antimicrobial-resistant (AMR) bacteria on that farm remains difficult to prove. In the pilot study presented here, we analysed total antimicrobial use on 50 dairy farms in Austria and also collected environmental samples to ascertain whether specific AMR bacteria were present. Antimicrobial use (AMU) analysis was based on electronic veterinary treatment records over a one-year period. Faecal samples for the assessment of extended-spectrum beta-lactamase (ESBL)-producing E. coli were collected from cowsheds, calf pens, and youngstock housing areas, as well as dust samples from barns, to isolate methicillin-resistant Staphylococcus aureus (MRSA). Bacteriological cultures were carried out on selective agar. Farms were split into groups of 25 of the highest antimicrobial users and 25 of the lowest users. Overall, samples from 13/50 (26.0%) farms were found to be positive for the presence of ESBL-producing E. coli. Of these, eight farms were in the low user group and five were in the high user group. Only one farm was confirmed to harbour MRSA. Statistical analyses demonstrated that there was no significant difference in this study population between high or low antimicrobial use with respect to the presence of ESBL-producing E. coli on farms (p = 0.33). In conclusion, the presence of specific AMR bacteria on farms in this study population was not found to have a statistically proven relationship with their level of antimicrobial use. eng Spectrum Beta-Lactamase; Staphylococcus-Aureus Mrsa; Food-Producing Animals; Escherichia-Coli; Extended-Spectrum; Antibiotic-Resistance; Risk-Factors; Prevalence; Herds; Milk 2023-06-29T11:56:15.958Z LOMv1.0 Author BEGIN:VCARD VERSION:3.0 N:Firth;Clair L.; FN:Clair L. Firth X-ORCID:https://orcid.org/0000-0002-4919-7786 END:VCARD BEGIN:VCARD VERSION:3.0 N:Obritzhauser;Walter; FN:Walter Obritzhauser END:VCARD BEGIN:VCARD VERSION:3.0 N:Koeberl-Jelovcan;Sandra; FN:Sandra Koeberl-Jelovcan END:VCARD BEGIN:VCARD VERSION:3.0 N:Käsbohrer;Annemarie; FN:Annemarie Käsbohrer X-ORCID:https://orcid.org/0000-0003-2966-2713 END:VCARD BEGIN:VCARD VERSION:3.0 N:Pless;Peter; FN:Peter Pless END:VCARD https://w3id.org/kim/hcrt/scheme https://w3id.org/kim/hcrt/text Textdokument Text LOMv1.0 yes https://creativecommons.org/licenses/by/4.0 application/pdf 1423213 https://phaidra.vetmeduni.ac.at/o:1779 https://phaidra.vetmeduni.ac.at/api/object/o:1779/thumbnail LOMv1.0 discipline