title: Short-term effects of amoxicillin on bacterial communities in manured soil.
abstract: Antibiotic-resistant bacteria, nutrients and antibiotics that enter the soil by means of manure may enhance the proportion of bacteria displaying antibiotic resistance among soil bacteria and may affect bacterial community structure and function. To investigate the effect of manure and amoxicillin added to manure on soil bacterial communities, microcosm experiments were performed with two soil types and the following treatments: (1) nontreated, (2) manure-treated, (3) treated with manure supplemented with 10 mg amoxicillin kg(-1) soil and (4) treated with manure supplemented with 100 mg amoxicillin kg(-1) soil, with four replicates per treatment. Manure significantly increased the total CFU count and the amoxicillin-resistant CFU count of both soil types. However, only the soil with a history of manure treatment showed a significant increase in the relative number of amoxicillin-resistant bacteria as a result of amoxicillin amendment. The majority of plasmids exogenously isolated from soil originated from soil treated with amoxicillin-supplemented manure. All 16 characterized plasmids carried the bla-TEM gene, and 10 of them belonged to the IncN group. The bla-TEM gene was detected in DNA directly extracted from soil by dot-blot hybridization of PCR amplicons and showed an increased abundance in soil samples treated with manure. Molecular fingerprint analysis of 16S rRNA gene fragments amplified from soil DNA revealed significant effects of manure and amoxicillin on the bacterial community of both soils.
authors.affiliation: Federal Biological Research Centre for Agriculture and Forestry, Braunschweig, Germany.
authors.forename: Chu Thi Thanh
authors.initials: CT
authors.lastname: Binh
authors.forename: Holger
authors.initials: H
authors.lastname: Heuer
authors.forename: Newton C Marcial
authors.initials: NC
authors.lastname: Gomes
authors.forename: Anja
authors.initials: A
authors.lastname: Kotzerke
authors.forename: Melanie
authors.initials: M
authors.lastname: Fulle
authors.forename: Bernd-Michael
authors.initials: BM
authors.lastname: Wilke
authors.forename: Michael
authors.initials: M
authors.lastname: Schloter
authors.forename: Kornelia
authors.initials: K
authors.lastname: Smalla
mesh_terms: D000658:Amoxicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001173:Arthrobacter / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D001419:Bacteria / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development*; D015169:Colony Count, Microbial; D003227:Conjugation, Genetic; D003470:Culture Media; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D020459:Genes, rRNA; D007778:Lactobacillus / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D008372:Manure / Q000382:microbiology*; D008969:Molecular Sequence Data; D010403:Penicillin Resistance / Q000235:genetics; D010957:Plasmids; D011549:Pseudomonas / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D008372:Manure; D012336:RNA, Ribosomal, 16S; D000658:Amoxicillin