Naslov
Manure fertilization increases resident antibiotic-resistant bacteria in soil

Autori
Udikovic-Kolic, Nikolina ; Wichmann, Fabienne ; Handelsmann, Jo

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
3rd International Symposium on the Environmental Dimension of Antibiotic Resistance

Mjesto i datum
Wernigerode, Njemačka, 17.05.2015. - 21.05.2015

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
antibiotic resistance; manure; beta-lactam; soil; bacterial community

Sažetak
Introduction: The increasing prevalence of antibiotic resistant bacteria is a serious public health threat. There is growing evidence that agricultural use of antibiotics contributes to the spread of antibiotic resistance genes in the environment, including to human pathogens. Manures from farm animals are commonly used as soil fertilizers, and they are also important reservoirs of antibiotic resistance genes. However, we know very little about the mechanisms by which manure fertilization influences the behavior of resistance genes in the environment. Objectives: The objective of this study was to assess the impact of cow manure on the ß-lactam resistance profile and composition of bacterial communities in soil. Materials & Methods: We treated soil with either inorganic fertilizer (NPK) or manure from dairy cows with no history of antibiotic treatment. Total and beta-lactam resistant bacteria in soil before and after fertilization were monitored by culturing. Functional metagenomics was used to identify resistance genes in soil and manure and quantitative PCR (qPCR) to quantify these genes in soil over time. 454 sequencing was used to assess overall changes in community structure in soil by manure treatment. Results: Culturing showed that the soil treated with manure contained a higher abundance of β- lactam resistant bacteria than soil treated with NPK. Functional metagenomics indicated that the higher levels of resistant bacteria in manure-amended soil was attributable to an enrichment of resident soil bacteria that harbor β-lactamases. qPCR showed that manure treatment enriched the bla(CEP-04) gene, which is highly similar (96%) to a gene found previously in a Pseudomonas sp. Analysis of 16S rRNA genes indicated that the abundance of Pseudomonas spp. increased in manure-amended soil. Populations of other soil bacteria that commonly harbor β-lactamases, including Janthinobacterium sp. and Psychrobacter pulmonis, also increased in response to manure treatment. Conclusion: Our results indicate that manure fertilization may lead to blooms of certain antibiotic resistant subpopulation of the soil community, even when the manure comes from cows that have not been treated with antibiotics. These data demonstrate the importance of nonintuitive impacts of agricultural practices on the intrinsic resistance of soil microbial communities.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Biotehnologija

POVEZANOST RADA