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Why are we interested in pathogens associated with AFOs?

Why are we interested in pathogens associated with AFOs?. AFOs house a large number of animals in a small area => large amount of fecal waste Swine may produce 5 to 10 times the amount of fecal waste as an equal number of humans

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Why are we interested in pathogens associated with AFOs?

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  1. Why are we interested in pathogens associated with AFOs? AFOs house a large number of animals in a small area => large amount of fecal waste • Swine may produce 5 to 10 times the amount of fecal waste as an equal number of humans Fecal waste from AFOs can contain high numbers of microbial pathogens • These can be zoonotic (capable of infecting both humans and animals) • Ex. E. coli 0157, Salmonella, Campylobacter, Hepatitis E (?), Cryptosporidium AFOs are largely unregulated for pathogens • New CAFO regulations > no provisions for regulation of pathogens

  2. Other Considerations for Environmental Monitoring Programs for AFO Pathogens: Type and efficiency of AFO waste treatment system • Conventional system • anaerobic lagoon systems followed by land application (swine – cattle) • land application of solid waste/litter (turkey – poultry) • Alternative systems (other treatment technologies) • “Smithfield Foods/PSF/NC Attorney General” Agreement Microbial Methods: • Initial sampling, concentration, or recovery methods • Pathogen detection and isolation methods • Pathogen confirmation and further characterization • Where did the fecal waste come from?? (source tracking)

  3. Considerations for Pathogen Detection Associated with AFOs: Salmonella Hepatitis E Virus Cryptosporidium • Use of indicator organisms? • Pathogens • Class of pathogen • Environmental Media • Water and wastewater • Biosolids and litter • Soils and vegetation • Air • Vectors

  4. Pathogen Analysis, Monitoring, and Surveillance • Pathogen detection from environmental samples is technically demanding, often tedious, slow to produce results, sometimes unreliable, and expensive • Done routinely in the health care field (clinical diagnostic microbiology): • often essential to patient treatment and care • provides national surveillance of infectious disease epidemiology • Regularly for some pathogens in some foods (meat & poultry) • Sometimes for human (municipal) biosolids • Rarely for monitoring or managing environmental waters • pathogen occurrence surveys: • ICR (Information Collection Rule): survey (18 months) for Giardia, Cryptosporidium and enteric viruses in larger drinking water supplies using surface water sources • GWDR (Ground Water Disinfection Rule): enteric virus survey in ground water sources of drinking water

  5. Microbial Indicators of Fecal Contamination • Traditional approach to assess the "sanitary" quality of water with respect to fecal contamination. • Quantify bacteria commonly present in intestines of warm blooded animals: • high numbers • easy to measure • surrogates for pathogens, especially bacterial pathogens. • May not be reliable indicators of • viruses and parasites

  6. Bacterial Indicators of Fecal Contamination in Water Total coliforms: standards for drinking waters; not feces‑specific (environmental sources). Fecal ("thermotolerant") coliforms: standards for wastewater effluents and biosolids, ambient surface waters and shellfish harvest waters; not feces-specific. E. coli: the "fecal" coliform; may occur naturally in tropics. Enterococci:Streptococcus faecalis and S. faecium; a sub‑set of the fecal streptococci considered more feces‑specific; EPA standards for bathing water quality. Clostridium perfringens: anaerobe; feces‑specific?; very (too?) resistant spores; candidate indicator for protozoan cysts.

  7. E. coli Famp F+ F+ Coliphage Viral Indicators of Fecal Contamination in Water • Coliphages: viruses (bacteriophages) infecting E. coli or other coliforms; attach directly to cell wall (somatic) • heterogeneous group • may not be feces-specific • host-dependent detection • Male-specific (F+) coliphages: coliphages infecting "male" strains of E. coli (posses pili) • may be feces-specific • may distinguish human from animal fecal contamination by group classification • II & III human; I & IV animal • PROBLEM: swine may harbor groups II & III also E. coli C Somatic Coliphage F+ Coliphage Somatic Coliphage

  8. USEPA 503 Regulations/Methods for Biosolids • Fecal Coliform (FC) bacteria (< 1,000 / g) and Salmonella (< 3 / 4g) • FC: Multiple fermentation tube method (MPN) • Salmonella: broth enrich, isolate colony, biochemical tests • Total Culturable Viruses (< 1 / 4g) • Elute biosolids with beef extract • Acid precipitation > raise pH to neutral • Cell culture plaque assay method on “Buffalo Green monkey Kidney cells” (BGMK) • Helminthova (< 1 / 4g) • elute with buffered water (+ surfactant) • zinc sulfate flotation method • acid-alcohol/solvent extraction • embryonate with (0.1 N) sulfuric acid or formaldehyde water at RT (26oC) • Microscopic evaluation for viability

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