Skip to main content
ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Produce Safety and Microbiology Research » Research » Publications at this Location » Publication #310094
Title: Survival of Salmonella enterica in aerated and nonaerated wastewaters from dairy lagoons

Author
item Ravva, Subbarao
item Sarreal, Chester

Submitted to: International Journal of Environmental Research and Public Health
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/21/2014
Publication Date: 10/29/2014
Citation: Ravva, S.V., Sarreal, C.Z. 2014. Survival of Salmonella enterica in aerated and nonaerated wastewaters from dairy lagoons. International Journal of Environmental Research and Public Health. 11:11249-11260.

Interpretive Summary: An estimated 1.3 million cases of foodborne illnesses, resulting in over 15,000 hospitalizations and 550 deaths in the USA, are linked annually to infections caused by non-typhoidal Salmonella. The largest multi-state outbreak of the decade that sickened 1535 people in 42 states in 2008 resulted from the consumption of jalapeno and Serrano peppers contaminated with Salmonella Typhimurium. Outbreaks are frequently associated with consumption of contaminated food or drinking water that was exposed to pathogen-laden animal manure or irrigation water tainted with manure. Designing effective and sustainable intervention strategies requires an understanding of pathogen prevalence and survival dynamics in farm environments. We evaluated earlier the influence of aeration on the survival of pathogenic Escherichia coli O157:H7 and observed that aeration did not enhance the destruction of the pathogen under both aerated and nonaerated conditions. Thus, we determined the fate of outbreak strains of Salmonella in wastewater from dairy manure flush holding lagoons with and without circulating aerators to examine the impact of aeration. Salmonellae decreased significantly from aerated microcosms prepared from wastewaters from lagoons equipped with circulating aerators in comparison to nonaerated microcosms.

Technical Abstract: Salmonella is the most commonly identified foodborne pathogen in produce, meat and poultry. Cattle are known reservoirs of Salmonella and the pathogen excreted in feces end up in manure flush lagoons. Salmonella enterica survival was monitored in wastewater from on-site holding lagoons equipped with or without circulating aerators at two dairies. All strains had poor survival rates and none proliferated in waters from aerated or settling lagoons. Populations of all three Salmonella serovars declined rapidly with decimal reduction times (D) of < 2 days in aerated microcosms prepared from lagoon equipped with circulators. Populations of Salmonella decreased significantly in aerated microcosms (D = 4.2 d) compared to nonaerated waters (D = 7.4 d) and in summer months (D = 3.4 d) compared to winter (D = 9.0 d). We propose holding the wastewater for sufficient decimal reduction cycles in lagoons to yield pathogen-free nutrient-rich water for crop irrigations and fertilization.