Monitoring Dairy Silage for Five Bacterial Groups with Potential for Human Pathogenesis

Abstract

Two types of silage routinely used at a dairy research facility were monitored over a 20 month period for five bacterial groups which have been associated with human pathogenesis. Those monitored were Listeria monocytogenes, Yersinia enterocolitica (motile), motile aeromonads, Campylobacter sp., and enterohemorrhagic Escherichia coli. Of 46 total silage samples, 8.7% were positive for L monocytogenes, 6.5% for Y. enterocolitica, and 10.9% for motile aeromonads. Campylobacter spp. and enterohemorrhagic E. coli were not isolated. The presence of pathogens was associated with elevated pH in silage samples.