Publikationsdatenbank

Effects of C/N ratio and moisture content on the survival of ESBL-producing Escherichia Coli during chicken manure composting (2019)

Art

Vortrag

Autoren

Thomas, C.

Idler, C.

Ammon, C.

Amon, T. (WE 10)

Kongress

71. Jahrestagung der Deutschen Gesellschaft für Hygiene und Mikrobiologie (DGHM)

Göttingen, 25. – 27.02.2019

Quelle

ABSTRACTBAND 71. Jahrestagung der Deutschen Gesellschaft für Hygiene und Mikrobiologie (DGHM) e. V. — Deutsche Gesellschaft für Hygiene und Mikrobiologie (DGHM) e. V. (Hrsg.)

Jena: Conventus Congressmanagement & Marketing GmbH, 2019 — S. 94

ISBN: 978-3-948023-01-0

Verweise

URL (Volltext): https://www.dghm-vaam.de/

Kontakt

Institut für Tier- und Umwelthygiene

Robert-von-Ostertag-Str. 7-13
14169 Berlin
+49 30 838 51845
tierhygiene@vetmed.fu-berlin.de

Abstract / Zusammenfassung

The high prevalence of extended-spectrum-ß-lactamase (ESBL)-producing Escherichia (E.) coliin European broiler farms leads to the possible dissemination of antibiotic-resistant strains into the environment using contaminated feces as organic fertilizer. The aim of the present study was to determine the effects of the carbon/nitrogen (C/N) ratio and the moisture content on the reduction kinetics of an artificially added ESBL-producing E. colistrain during lab-scale composting of chicken manure in bioreactors.Four bioreactors were filled with four different compost mixtures consisting of chicken manure, wheat straw and water. The two initial C/N ratios of 10:1 and 40:1 were each combined with an initial dry matter content (DM) of 40 % and 80 %. The compost mixtures were spiked with a commensal ESBL-producing E. colistrain that was isolated from chicken feces and carries the blaCTX-M15 gene. Initial levels of 107 colony forming units (cfu)/g in the mixtures were achieved. The bioreactors were then incubated at 40°C and the number of E. coliwas determined daily for ten consecutive days. In addition, the temperature profile within each bioreactor was recorded. All samples were also analyzed for total ammoniacal nitrogen, volatile fatty acids and pH. The experiment was conducted twice.The fastest reduction of E. colinumbers occurred for both compost mixtures with a C/N ratio of 10:1. After 48hours, the number of E. coliwas below the detection limit (< 102 cfu/ml). Additionally, the dry mixtures led to a faster reduction compared to the moist mixtures despite lower maximum temperatures. The temperatures within the bioreactors were lower in mixtures with a C/N ratio of 40:1 compared to the mixtures with a C/N ratio of 10:1. After 10 days, E. coliwere only still detectable in the mixture with a C/N ratio of 40:1 and 40 % DM.In conclusion, composting of chicken manure is a suitable method to reduce antibiotic-resistant E. coliin chicken manure. Especially mixtures typical for chicken manure with a low C/N ratio and a high DM content lead to the rapid reduction of ESBL-producing E. coli.