Efficacy of NH3 as a secondary barrier treatment for inactivation of Salmonella Typhimurium and methicillin-resistant Staphylococcus aureus in digestate of animal carcasses: Proof-of-concept

PLoS One. 2017 May 5;12(5):e0176825. doi: 10.1371/journal.pone.0176825. eCollection 2017.

Abstract

Managing the disposal of infectious animal carcasses from routine and catastrophic disease outbreaks is a global concern. Recent research suggests that burial in lined and aerated trenches provides the rapid pathogen containment provided by burial, while reducing air and water pollution potential and the length of time that land is taken out of agricultural production. Survival of pathogens in the digestate remains a concern, however. A potential answer is a 'dual'-barrier approach in which ammonia is used as a secondary barrier treatment to reduce the risk of pathogen contamination when trench liners ultimately leak. Results of this study showed that the minimum inhibitory concentration (MIC) of NH3 is 0.1 M (~1,468 NH3-N mg/L), and 0.5 M NH3 (~7,340 NH3-N mg/L) for ST4232 & MRSA43300, respectively at 24 h and pH = 9±0.1 and inactivation was increased by increasing NH3 concentration and/or treatment time. Results for digestate treated with NH3 were consistent with the MICs, and both pathogens were completely inactivated within 24 h.

MeSH terms

  • Ammonia / pharmacology*
  • Animals
  • Communicable Diseases / epidemiology
  • Digestion
  • Disease Outbreaks
  • Meat / microbiology*
  • Methicillin-Resistant Staphylococcus aureus / drug effects*
  • Salmonella typhimurium / drug effects*

Substances

  • Ammonia

Grants and funding

This work was supported by Republic of Korea Rural Development Administration through a grant from the National Institute of Animal Science (Project title: Development of environmentally friendly livestock mortality disposal system using aerobic digestion. Project no.: PJ90713006). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.