General Suppression of Escherichia coli O157:H7 in Sand-Based Dairy Livestock Bedding

Department of Plant Pathology, The Ohio State University, OARDC, 1680 Madison Avenue, Wooster, OH 44691, USA.
Applied and Environmental Microbiology (Impact Factor: 3.67). 03/2011; 77(6):2113-21. DOI: 10.1128/AEM.01655-10
Source: PubMed


Sand bedding material is frequently used in dairy operations to reduce the occurrence of mastitis and enhance cow comfort. One objective of this work was to determine if sand-based bedding also supported the microbiologically based suppression of an introduced bacterial pathogen. Bedding samples were collected in summer, fall, and winter from various locations within a dairy operation and tested for their ability to suppress introduced populations of Escherichia coli O157:H7. All sources of bedding displayed a heat-sensitive suppressiveness to the pathogen. Differences in suppressiveness were also noted between different samples at room temperature. At just 1 day postinoculation (dpi), the recycled sand bedding catalyzed up to a 1,000-fold reduction in E. coli counts, typically 10-fold greater than the reduction achieved with other substrates, depending on the sampling date. All bedding substrates were able to reduce E. coli populations by over 10,000-fold within 7 to 15 dpi, regardless of sampling date. Terminal restriction fragment length polymorphism (T-RFLP) analysis was used to identify bacterial populations potentially associated with the noted suppression of E. coli O157:H7 in sand bedding. Eleven terminal restriction fragments (TRFs) were overrepresented in paired comparisons of suppressive and nonsuppressive specimens at multiple sampling points, indicating that they may represent environmentally stable populations of pathogen-suppressing bacteria. Cloning and sequencing of these TRFs indicated that they represent a diverse subset of bacteria, belonging to the Cytophaga-Flexibacter-Bacteroidetes, Gammaproteobacteria, and Firmicutes, only a few of which have previously been identified in livestock manure. Such data indicate that microbial suppression may be harnessed to develop new options for mitigating the risk and dispersal of zoonotic bacterial pathogens on dairy farms.

Download full-text


Available from: Michele L Williams
  • Source
    • "However, most of the reports indicated that fungi (Takahashi et al., 2008; van Elsas et al., 2012), actinomycetes (Kim et al., 2011; van Elsas et al., 2012), Firmicutes (Westphal et al., 2011), Bacteroidetes, β-and γ-Proteobacteria (Westphal et al., 2011; Ma et al., 2013) can inhibit E. coli O157:H7 survival. Westphal et al. (2011) proposed that microbial suppression may be harnessed to develop new options for mitigating the risk and dispersal of zoonotic bacterial pathogens in the environment. Thus, further study to assess the impact of indigenous microorganisms on the survival of E. coli O157:H7 in soils would provide support information for reducing the negative environmental risk by the pathogen. "
    [Show abstract] [Hide abstract]
    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.
    Full-text · Article · Apr 2014 · Science of The Total Environment
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Shiga toxin-producing E. coli O157:H7 has been implicated in many foodborne illnesses caused by the consumption of contaminated fresh produce. However, data on the role of microbial communities on its persistence in major fresh produce-growing soils are limited. In this study, survival of E. coli O157:H7 in 32 soils (16 organically and 16 conventionally managed soils) from California (CA) and Arizona (AZ) was investigated. Our goal was to correlate the survival time of E. coli O157:H7 in soils with 16S rRNA 454-pyrosequencing based bacterial community composition. Results showed that the longest survival time (ttd, detection limit of 100 CFU g(-1) dry soil) of E. coli O157:H7 was observed in the soils from Salinas Valley area, CA and in organic soils from Yuma, AZ. Kohonen self-organizing map of E. coli survival and associated soil chemical, physical and biological variables using artificial neural network analysis showed that survival of E. coli O157:H7 in soils was negatively correlated with salinity (EC), but positively correlated with total nitrogen (TN) and water soluble organic carbon (WSOC). Bacterial diversity as determined by the Shannon diversity index had no significant (P = 0.635) effect on ttd, but individual bacterial phyla had different effects. The survival of E. coli O157:H7 was positively correlated with the abundances of Actinobacteria (P < 0.001) and Acidobacteria (P < 0.05), and negatively correlated with those of Proteobacteria and Bacteroidetes (P < 0.05). Our data showed that specific groups of bacteria correlate with the persistence of E. coli O157:H7 in soils thus opening new ways to study the influence of certain bacterial phyla on persistence of this pathogen and other related pathogens in complex environments. © 2013 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.
    Full-text · Article · Jan 2013 · FEMS Microbiology Ecology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: ABSTRACT The dairy industry is changing on a global scale with larger, more efficient operations. The impact of this change on worker health and safety, specifically, associations between occupational lung disease and inhalation exposures, has yet to be reported in a comprehensive review of the scientific literature. Therefore, a three-tier process was used to identify information using a keyword search of online databases of scientific literature. Of the 147 citations reviewed, 52 met initial screening criteria, and 30 were included in this review. Dairy workers experience lung conditions such as asthma, chronic obstructive pulmonary disease, hypersensitivity pneumonitis, chronic bronchitis, and cancer. Recent pulmonary function studies have identified obstructive lung changes among dairy farm workers. The increased scale of dairy production with significant changes in technology and work practices has altered inhalation exposure patterns among dairy workers. The inhalation exposure in the dairy work environment may elicit differing inflammatory responses in relation to timing of initial exposure as well as to repeated exposures. Few studies have measured inhalation exposure while simultaneously assessing the impact of the exposure on lung function of dairy farm workers. Even fewer studies have been implemented to assess the impact of aerosol control technology to reduce inhalation exposure. Future research should evaluate worker exposure to aerosols through a task-based approach while utilizing novel methods to assess inhalation exposure and associated inflammatory responses. Finally, potential solutions should be developed and tested to reduce inhalation exposure to inflammatory agents and respiratory diseases in the dairy farm work environment.
    Full-text · Article · Jul 2013 · Journal of Agromedicine
Show more