Two-Dose Ceftiofur Treatment Increases Cephamycinase Gene Quantities and Fecal Microbiome Diversity in Dairy Cows Diagnosed with Metritis.

Antimicrobial resistance is a significant concern worldwide; meanwhile, the impact of 3rd generation cephalosporin (3GC) antibiotics on the microbial communities of cattle and resistance within these communities is largely unknown. The objectives of this study were to determine the effects of two-dose ceftiofur crystalline-free acid (2-CCFA) treatment on the fecal microbiota and on the quantities of second-and third-generation cephalosporin, fluoroquinolone, and macrolide resistance genes in Holstein-Friesian dairy cows in the southwestern United States. Across three dairy farms, 124 matched pairs of cows were enrolled in a longitudinal study.

Prevalence and Profiles of Antibiotic Resistance Genes (A) and in Extended-Spectrum Beta-Lactamase (ESBL)-Producing Isolated from Dairy Calf Feces.

The use of antibiotics to treat dairy calves may result in multidrug-resistant extended-spectrum beta-lactamase (ESBL)-producing . This study investigated fluoroquinolone and macrolide resistance genes among ESBL-producing isolated from dairy calves. Fresh fecal samples from 147 dairy calves across three age groups were enriched to select for ESBL-producing Plasmid-mediated fluoroquinolone (), macrolide ((A)), and beta-lactam ( groups 1 and 9) resistance genes were identified by PCR and gel electrophoresis in ESBL-producing .

Age Dependence of Antimicrobial Resistance Among Fecal Bacteria in Animals: A Scoping Review.

A phenomenon of decreasing antimicrobial resistance (AMR) among fecal bacteria as food animals age has been noted in multiple field studies. We conducted a scoping review to summarize the extent, range, and nature of research activity and the data for the following question: "does AMR among enteric/fecal bacteria predictably shift as animals get older?". This review followed a scoping review methodology framework.

Economic effects of policy options restricting antimicrobial use for high risk cattle placed in U.S. feedlots.

The rising public health threat of antimicrobial resistance, the influence of food service companies, as well as the overall lack of positive image of using medical products in intensive farming are major drivers curbing antimicrobial use. In the future, government policies may affect practices of antimicrobial use in beef production in feedlots, a prominent current user of antimicrobials in animal agriculture, but also the agricultural industry generating the highest cash receipt in the U.S.

The Occurrence and Characterization of Extended-Spectrum-Beta-Lactamase-Producing Isolated from Clinical Diagnostic Specimens of Equine Origin.

isolates were recovered from clinical specimens of equine patients admitted to the Texas A&M Veterinary Medical Teaching Hospital over a five-year period. Ceftiofur resistance was used as a marker for potential extended-spectrum beta-lactamase (ESBL)-activity, and of the 48 ceftiofur-resistant isolates, 27.08% ( = 13) were phenotypically ESBL-positive.

Antimicrobial Policies in United States Beef Production: Choosing the Right Instruments to Reduce Antimicrobial Use and Resistance Under Structural and Market Constraints.

Antimicrobial use (AMU) in animal agriculture contributes to the selection of resistant bacteria, potentially constituting a public health threat. To address antimicrobial resistance, public policies set by governments, as well as intra-sectoral approaches, can be implemented. In this paper, we explore how common policy instruments such as regulations, economic incentives, and voluntary agreements could help reduce AMU in beef production.

Effects of supplemental zinc sulfate on growth performance, carcass characteristics, and antimicrobial resistance in feedlot heifers.

Effects of supplemental Zn as Zn sulfate on feedlot performance, carcass traits, and antimicrobial resistance were evaluated using 480 crossbred heifers (BW = 385 kg ± 13.08) in a randomized complete block design. Heifers were blocked by BW and randomly assigned within block to diets with 0, 30, 60, or 90 mg supplemental Zn/kg DM.

Distribution of the Gene Cluster and Associated Genetic Determinants among Swine from a Controlled Feeding Trial.

Copper is used as an alternative to antibiotics for growth promotion and disease prevention. However, bacteria developed tolerance mechanisms for elevated copper concentrations, including those encoded by the operon in Gram-negative bacteria. Using cohorts of weaned piglets, this study showed that the supplementation of feed with copper concentrations as used in the field did not result in a significant short-term increase in the proportion of -positive fecal .