Murray, S.A.; Amachawadi, R.G.; Norman, K.N.; Lawhon, S.D.; Nagaraja, T.G.; Drouillard, J.S.; Scott, H.M. Effects of Zinc and Menthol-Based Diets on Co-Selection of Antibiotic Resistance among E. coli and Enterococcus spp. in Beef Cattle. Animals2021, 11, 259.
Murray, S.A.; Amachawadi, R.G.; Norman, K.N.; Lawhon, S.D.; Nagaraja, T.G.; Drouillard, J.S.; Scott, H.M. Effects of Zinc and Menthol-Based Diets on Co-Selection of Antibiotic Resistance among E. coli and Enterococcus spp. in Beef Cattle. Animals 2021, 11, 259.
Murray, S.A.; Amachawadi, R.G.; Norman, K.N.; Lawhon, S.D.; Nagaraja, T.G.; Drouillard, J.S.; Scott, H.M. Effects of Zinc and Menthol-Based Diets on Co-Selection of Antibiotic Resistance among E. coli and Enterococcus spp. in Beef Cattle. Animals2021, 11, 259.
Murray, S.A.; Amachawadi, R.G.; Norman, K.N.; Lawhon, S.D.; Nagaraja, T.G.; Drouillard, J.S.; Scott, H.M. Effects of Zinc and Menthol-Based Diets on Co-Selection of Antibiotic Resistance among E. coli and Enterococcus spp. in Beef Cattle. Animals 2021, 11, 259.
Abstract
Antimicrobial resistance (AMR) represents a growing crisis in both human and veterinary medicine. We evaluated the use of two categories of antibiotic alternatives – heavy metals and essential oils – in beef cattle, and their effects on gram-negative and gram-positive bacteria. In this randomized controlled field trial, we measured the impact of supplemental zinc and menthol on antimicrobial resistance among commensal enteric bacteria of feeder cattle. Fecal suspensions were plated onto plain- and antibiotic-supplemented MacConkey and m-Enterococcus agar for quantification of total and antimicrobial-resistant Escherichia coli and Enterococcus spp., respectively. Temporal effects on overall E. coli growth were significant (P< 0.05); however, there were no significant effects on antibiotic-supplemented agar. Zinc was associated with significant increases in growth on erythromycin-supplemented m-Enterococcus agar. Cattle fed zinc exhibited significantly higher macrolide resistance among fecal enterococci isolates.
Keywords
antibiotic resistance; antibiotic alternatives; heavy metals; essential oils
Subject
Biology and Life Sciences, Biochemistry and Molecular Biology
Copyright:
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