In-feed antibiotic effects on the swine intestinal microbiome

Abstract

Antibiotics have been administered to agricultural animals for disease treatment, disease prevention, and growth promotion for over 50 y. The impact of such antibiotic use on the treatment of human diseases is hotly debated. We raised pigs in a highly controlled environment, with one portion of the littermates receiving a diet containing performance-enhancing antibiotics [chlortetracycline, sulfamethazine, and penicillin (known as ASP250)] and the other portion receiving the same diet but without the antibiotics. We used phylogenetic, metagenomic, and quantitative PCR-based approaches to address the impact of antibiotics on the swine gut microbiota. Bacterial phylotypes shifted after 14 d of antibiotic treatment, with the medicated pigs showing an increase in Proteobacteria (1-11%) compared with nonmedicated pigs at the same time point. This shift was driven by an increase in Escherichia coli populations. Analysis of the metagenomes showed that microbial functional genes relating to energy production and conversion were increased in the antibiotic-fed pigs. The results also indicate that antibiotic resistance genes increased in abundance and diversity in the medicated swine microbiome despite a high background of resistance genes in nonmedicated swine. Some enriched genes, such as aminoglycoside O-phosphotransferases, confer resistance to antibiotics that were not administered in this study, demonstrating the potential for indirect selection of resistance to classes of antibiotics not fed. The collateral effects of feeding subtherapeutic doses of antibiotics to agricultural animals are apparent and must be considered in cost-benefit analyses.intestinal microbiota | microbiome shifts | swine bacteria | BioTrove microarray | metagenomics

Polygala tenuifolia extract inhibits lipid accumulation in 3T3-L1 adipocytes and high-fat diet–induced obese mouse model and affects hepatic transcriptome and gut microbiota profiles

“…In addition, 5-week PTE treatment decreased the population of Deferribacteres and increased that of Proteobacteria. These changes in gut microbiota profiles were similar to the evidence presented in previous reports for treating obesity with prebiotics (oligofructose) and antibiotics (vancomycin or penicillin) [64,65]. Furthermore, PTE treatment caused a reduction in both Lachnospiraceae and Ruminococcaceae populations, which positively correlate with obesity, in subjects fed a HFD [66,67].…”

Temporal changes of antibiotic-resistance genes and bacterial communities in two contrasting soils treated with cattle manure

“…The abundant and diverse ARGs found in antibiotic-free cattle manure are in line with the similar findings in previous studies (Looft et al 2012;Kyselkova et al 2013Kyselkova et al , 2015Wichmann et al 2014), which prompted us to explore the evolution and movement of these ARGs after manure application. Although land application of cattle manure is a common practice in crop production, current knowledge regarding the temporal patterns of ARGs following manure amendment is limited, which hinders our ability to reliably predict ARG behaviors in soil environment.…”

Effect of oxytetracycline as well as an acid-based feed supplement on the prevalence and abundance of selected antibiotic resistance genes in weaned piglets

“…In the beginning of the study, all faecal samples were positive for the selected resistance genes, although the piglets as well as their dams were never exposed to any antibiotics. A similar situation has been found in previous studies [28,29], which also reported the presence of background resistances in the absence of any antibiotic selective pressure. In our study, resistance gene copy numbers were higher in the pigs as in the sows (unpublished results) but decreased with time which might reflect age related differences in the microbiota.…”