Location: Contaminant Fate and Transport ResearchTitle: A glimpse of Escherichia coli O157:H7 survival in soils from eastern China Author
|Ibekwe, Abasiofiok - Mark|
Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/2/2014
Publication Date: 1/21/2014
Citation: Wang, H., Ibekwe, A.M., Ma, J., Wu, L., Lou, J., Wu, Z., Liu, R., Xu, J., Yates, S.R. 2014. A glimpse of Escherichia coli O157:H7 survival in soils from eastern China. Science of the Total Environment. 476-477:49-56. Interpretive Summary: Escherichia coli O157:H7 (E. coli O157:H7) is a food-borne pathogen that can cause watery diarrhea and various hemorrhagic illnesses. The infectious threshold of E. coli O157:H7 is very low and ingestion of as few as 10 cells may be sufficient to cause severe gastrointestinal illness. There have been numerous outbreaks and reported throughout the world, including China, with several hundred severe outbreaks with mortality as high as 5-10%. A study was conducted to provide novel insights into the survival of E. coli O157:H7 in the 14 Chinese soils. It was found that the survival of E. coli O157:H7 in these soils was controlled by multiple factors, with the type and population of indigenous microorganisms as the most important factors. Significantly longer E. coli O157:H7 survival was observed in the north-eastern Chinese soils than in south-eastern Chinese soils, indicating higher potential environmental risk of E. coli O157:H7 in north-eastern China. It was also found difficult to control the pathogen once they were introduced into soil. Therefore, it is critical to enhance the management of treating and storing farm waste to control E. coli O157:H7 dissemination into the environment. To our knowledge, this research is the first to report E. coli O157:H7 survival in Chinese soils and the findings will provide needed information to reduce its negative environmental impacts and ensuring food-safety and public health. This information will be of value to academia, regulatory, and grower communities.
Technical Abstract: Escherichia coli O157:H7 (E. coli O157:H7) is an important food-borne pathogen, which continues to be a major public health concern worldwide. It is known that E. coli O157:H7 survive in soil environment might result in the contamination of fresh produce or water source. To investigate how the soils and their properties affect E. coli O157:H7 survival, we studied E. coli O157:H7 survival dynamics in 14 soils collected in eastern China from the warm-temperate zone to subtropical zone. Results showed that E. coli O157:H7 survival as a function of time can be well described by the Weibull model. The calculated td values (survival time to reach the detection limit, 100 colony forming units per gram oven-dried weight of soil) for the test soils were between 1.4 and 25.8 days. A significantly longer survival time (td) was observed in neutral or alkaline soils from north-eastern China (the warm-temperate zone) than that in acidic soils from south-eastern China (the subtropical zone). Distinct E. coli O157:H7 survival dynamics was related to soil properties. Stepwise multiple regression analysis revealed that the td values were significantly enhanced by soil microbial biomass carbon and total nitrogen, but were significantly reduced by amorphous Al2O3 and relative abundance of Chloroflexi. It should pay more attention to E. coli O157:H7 long survival in soils and its potential environmental contamination risk.