1. Preventive antibiotic treatment of calves: emergence of dysbiosis causing propagation of obese state‐associated and mobile multidrug resistance‐carrying bacteria
- Author
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Igor Y. Morozov, Michael J. Duncan, Dorota A Dobrzanska, Lauren Acton, Jessica Rollason, Matthew Lamaudiere, John Simms, Gareth D. Weedall, and Sharon Compton
- Subjects
Florfenicol ,S1 ,medicine.drug_class ,lcsh:Biotechnology ,Antibiotics ,Bioengineering ,Gut flora ,Applied Microbiology and Biotechnology ,Biochemistry ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,Antibiotic resistance ,RA0421 ,lcsh:TP248.13-248.65 ,Drug Resistance, Bacterial ,Escherichia coli ,medicine ,Animals ,Humans ,SF ,Obesity ,Phylogeny ,Research Articles ,030304 developmental biology ,Thiamphenicol ,2. Zero hunger ,0303 health sciences ,Bacteria ,biology ,030306 microbiology ,biology.organism_classification ,medicine.disease ,Anti-Bacterial Agents ,Gastrointestinal Microbiome ,Resistome ,Multiple drug resistance ,chemistry ,Dysbiosis ,Cattle ,Female ,Research Article ,Biotechnology - Abstract
Summary In agriculture, antibiotics are used for the treatment and prevention of livestock disease. Antibiotics perturb the bacterial gut composition but the extent of these changes and potential consequences for animal and human health is still debated. Six calves were housed in a controlled environment. Three animals received an injection of the antibiotic florfenicol (Nuflor), and three received no treatment. Faecal samples were collected at 0, 3 and 7 days, and bacterial communities were profiled to assess the impact of a therapy on the gut microbiota. Phylogenetic analysis (16S‐rDNA) established that at day 7, antibiotic‐treated microbiota showed a 10‐fold increase in facultative anaerobic Escherichia spp, a signature of imbalanced microbiota, dysbiosis. The antibiotic resistome showed a high background of antibiotic resistance genes, which did not significantly change in response to florfenicol. However, the maintenance of Escherichia coli plasmid‐encoded quinolone, oqxB and propagation of mcr‐2, and colistin resistance genes were observed and confirmed by Sanger sequencing. The microbiota of treated animals was enriched with energy harvesting bacteria, common to obese microbial communities. We propose that antibiotic treatment of healthy animals leads to unbalanced, disease‐ and obese‐related microbiota that promotes growth of E. coli carrying resistance genes on mobile elements, potentially increasing the risk of transmission of antibiotic resistant bacteria to humans., Antibiotic treatment leads to expansion of facultative anaerobic Escherichia spp. (proteobacteria) in calves, a signature of imbalanced microbiota, dysbiosis. This in turn enhances a risk of the growth of bacteria that carry highly mobile clinically relevant resistances that can be transmitted to humans.
- Published
- 2020