Zeitschriftenaufsatz | 2026 Open Access

Evaluation of ß-lactamase-induced inactivation of penicillin G and cefoperazone in spiked ultra-high temperature and raw unpasteurized milk.

Autor:in
Ludewig, M.; Firth, C. L.; Roschitz, M.; Hinterleithner, S. H.; Käsbohrer, A.
Publikationen als Autor:in / Herausgeber:in der Vetmeduni
Ludewig, Martina; Käsbohrer, Annemarie; Firth, Clair
Journal
Frontiers in Veterinary Science
Schlagwörter
antibiotics; enzymes; microbiological counts; pH; waste milk; ß-lactamase
Dokumenten­typ
Originalarbeit
CC Lizenz
CC-BY
Open Access Type
Gold
DOI
Öffnen URL 10.3389/fvets.2026.1808217
PubMed ID
Öffnen URL 42368350
SDG Hauptzuordnung
12 … Nachhaltiger Konsum und Produktion
SDG Nebenzuordnung
03 … Gesundheit und Wohlergehen

Weitere Details

Band
13
Startseite
1808217
In Austria, veterinary medicinal products (VMPs) containing penicillin G or cefoperazone are frequently used to treat dairy cows, which leads to the production of non-saleable waste milk. This study aimed to determine the loss of detectable antimicrobial activity of penicillin G and cefoperazone using a commercial ß-lactamase preparation, Antipen®. Ultra-high-temperature (UHT) processed and raw unpasteurized milk were spiked with penicillin G and cefoperazone (both pure pharmaceutical substances and VMPs), and the effects of temperature (37 °C, 25 °C, and 10 °C), storage time, and pH on Antipen® treatment on antibiotic activity were investigated. The aerobic mesophilic count (AMC) and Enterobacteriaceae before and after enzyme treatment in raw milk were also examined to assess the microbiological quality of milk that is potentially fed to calves. The VMPs containing penicillin G (Vanapen®) or cefoperazone (Peracef®) in 50 mL of UHT or raw milk showed a higher stability after Antipen® treatment compared to pure antibiotic substances. Concentrations of 300 μg/mL of Vanapen® tested negative by Delvotest® T under all experimental conditions (12- and 6-h treatment, at natural pH and pH 5.5, at 37-10 °C). Treatments of milk with natural pH spiked with 10 μg/mL of Peracef® tested negative for the antibiotic after 12 and 6 h at 37 °C, while after acidification of the milk to pH 5.5, 10 μg/mL Peracef® was undetectable at all temperatures and time periods. In milk with natural pH treated with Antipen® for 12 h at 10-37 °C, the values of AMC always exceeded 5.0-log cfu/mL, indicating that the milk is not suitable for use as calf feed without prior acidification or subsequent pasteurization. Reducing the exposure time to 6 h or acidifying the milk to a pH of 5.5 during 12-h treatment significantly reduced bacterial growth. This study demonstrated that Antipen® can effectively degrade penicillin, although its efficacy is lower and slower on cephalosporins. Since the study was conducted in a laboratory setting, extrapolation of the effective treatment durations to on-farm application requires validation in practical, real-world conditions. Copyright © 2026 Ludewig, Firth, Roschitz, Hinterleithner and Käsbohrer.

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