Journal of Applied Microbiology, Vol.117, No.2, 417-429, 2014
Run-off studies demonstrate parallel transport behaviour for a marker of poultry fecal contamination and Staphylococcus aureus
Aims: To determine whether poultry litter marker gene LA35 is correlated with pathogens and fecal indicator bacteria (FIB) in run-off from poultry litter-amended plots. Methods and Results: A rainfall simulator with various vegetative filter strip lengths was employed to evaluate the correlation of a microbial source tracking (MST) marker for poultry feces/litter (the 16S rRNA gene of Brevibacterium sp. LA35 [LA35] measured by quantitative PCR) with pathogens and FIB in runoff. LA35 was correlated with Staphylococcus aureus, Escherichia coli, Enterococcus spp. and Bacteroidales levels. Salmonella was present at low concentration in litter, but became undetectable by qPCR in run-off. Escherichia coli, LA35 and Staph. aureus exhibited mass-based first flush behaviour in the run-off. Conclusions: Correlation of LA35 with FIB and pathogens in run-off from poultry litter-amended fields suggest comparable transport mechanisms and that LA35 is a useful tracer for harmful bacteria in the environment released from poultry litter. Significance and Impact of the Study: To protect human health, an effective marker for poultry fecal contamination should exhibit similar fate and transport characteristics compared to pathogens. This study is among the first to demonstrate such a relationship in run-off for a MST marker.
Keywords:Brevibacterium;microbial source tracking;nonpoint source pollution;poultry feces;vegetated filter strips;water quality