Manure Source and Age Affect Survival of Zoonotic Pathogens during Aerobic Composting at Sublethal Temperatures

2015 ◽  
Vol 78 (2) ◽  
pp. 302-310 ◽  
Author(s):  
MARILYN C. ERICKSON ◽  
CHRIS SMITH ◽  
XIUPING JIANG ◽  
IAN D. FLITCROFT ◽  
MICHAEL P. DOYLE
Keyword(s):  
C:N Ratio ◽  
Animal Manure ◽  
Escherichia Coli O157 ◽  
Pathogen Inactivation ◽  
Aerobic Composting ◽  
E Coli ◽  
Initial Carbon ◽  
Nitrogen Amendment ◽  
Chicken Litter ◽  
Different Sources

Heat is the primary mechanism by which aerobic composting inactivates zoonotic bacterial pathogens residing within animal manures, but at sublethal temperatures, the time necessary to hold the compost materials to ensure pathogen inactivation is uncertain. To determine the influence of the type of nitrogen amendment on inactivation of Salmonella, Listeria monocytogenes, and Escherichia coli O157:H7 in compost mixtures stored at sublethal temperatures, specific variables investigated in these studies included the animal source of the manure, the initial carbon/nitrogen (C:N) ratio of the compost mixture, and the age of the manure. Salmonella and L. monocytogenes were both inactivated more rapidly in chicken and swine compost mixtures stored at 20°C when formulated to an initial C:N ratio of 20:1 compared with 40:1, whereas a C:N ratio did not have an effect on inactivation of these pathogens in cow compost mixtures. Pathogen inactivation was related to the elevated pH of the samples that likely arises from ammonia produced by the indigenous microflora in the compost mixtures. Indigenous microbial activity was reduced when compost mixtures were stored at 30°C and drier conditions (<10% moisture level) were prevalent. Furthermore, under these drier conditions, Salmonella persisted to a greater extent than L. monocytogenes, and the desiccation resistance of Salmonella appeared to convey cross-protection to ammonia. Salmonella persisted longer in compost mixtures prepared with aged chicken litter compared with fresh chicken litter, whereas E. coli O157:H7 survived to similar extents in compost mixtures prepared with either fresh or aged cow manure. The different responses observed when different sources of manure were used in compost mixtures reveal that guidelines with times required for pathogen inactivation in compost mixtures stored at sublethal temperatures should be dependent on the source of nitrogen, i.e., type of animal manure, present.

Inactivation of Escherichia coli O157:H7 in Nonintact Beefsteaks of Different Thicknesses Cooked by Pan Broiling, Double Pan Broiling,or Roasting by Using Five Types of Cooking Appliances

2010 ◽  
Vol 73 (3) ◽  
pp. 461-469 ◽  
Author(s):  
CANGLIANG SHEN ◽  
JEREMY M. ADLER ◽  
IFIGENIA GEORNARAS ◽  
KEITH E. BELK ◽  
GARY C. SMITH ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Thermal Inactivation ◽  
Sodium Tripolyphosphate ◽  
Cooking Methods ◽  
Escherichia Coli O157 ◽  
Target Temperature ◽  
Pathogen Inactivation ◽  
Total Water ◽  
E Coli ◽  
George Foreman

This study compared thermal inactivation of Escherichia coli O157:H7 in nonintact beefsteaks of different thicknesses by different cooking methods and appliances. Coarsely ground beef was inoculated with rifampin-resistant E. coli O157:H7 (eight-strain composite, 6 to 7 log CFU/g) and then mixed with sodium chloride (0.45%) plus sodium tripolyphosphate (0.23%); the total water added was 10%. The meat was stuffed into bags (10-cm diameter), semifrozen (−20°C, 6 h), and cut into 1.5-, 2.5-, and 4.0-cm-thick steaks. Samples were then individually vacuum packaged, frozen (−20°C, 42 h), and tempered (4°C, 2.5 h) before cooking. Partially thawed (−2 ± 1°C) steaks were pan broiled (Presto electric skillet and Sanyo grill), double pan broiled (George Foreman grill), or roasted (Oster toaster oven and Magic Chef standard kitchen oven) to a geometric center temperature of 65°C. Extent of pathogen inactivation decreased in order of roasting (2.0 to 4.2 log CFU/g) > pan broiling (1.6 to 2.8 log CFU/g) ≥ double pan broiling (1.1 to 2.3 log CFU/g). Cooking of 4.0-cm-thick steaks required a longer time (19.8 to 65.0 min; variation was due to different cooking appliances), and caused greater reductions in counts (2.3 to 4.2 log CFU/g) than it did in thinner samples (1.1 to 2.9 log CFU/g). The time to reach the target temperature increased in order of George Foreman grill (3.9 to 19.8 min) < Oster toaster oven (11.3 to 45.0 min) < Presto electric skillet (16.3 to 55.0 min) < Sanyo grill (14.3 to 65.0 min) < standard kitchen oven (20.0 to 63.0 min); variation was due to steak thickness. Results indicated that increased steak thickness allowed greater inactivation of E. coli O157:H7, as time to reach the target internal temperature increased. Roasting in a kitchen oven was most effective for pathogen inactivation.

Thermal and Nonthermal Factors Affecting Survival of Salmonella and Listeria monocytogenes in Animal Manure–Based Compost Mixtures

2014 ◽  
Vol 77 (9) ◽  
pp. 1512-1518 ◽  
Author(s):  
M. C. ERICKSON ◽  
J. LIAO ◽  
L. MA ◽  
X. JIANG ◽  
M. P. DOYLE
Keyword(s):  
Listeria Monocytogenes ◽  
Fluorescent Protein ◽  
C:N Ratio ◽  
Initial Moisture Content ◽  
Swine Manure ◽  
Field Application ◽  
Potential Contribution ◽  
Pathogen Inactivation ◽  
Aerobic Composting ◽  
Pathogen Populations

Reduction of enteric pathogens in animal manures before field application is essential for mitigating the risk of foodborne illness associated with produce. Aerobic composting of manures has been advocated as an effective treatment for reducing pathogen populations, and heat is a major factor contributing to pathogen inactivation. This study was initiated to determine the potential contribution of both thermal and nonthermal (pH, volatile acids, and ammonia) factors to pathogen inactivation during aerobic composting in bioreactors for mixtures containing manure from various sources (dairy, chicken, and swine). The test mixtures were formulated with an initial moisture content of 60% and a C:N ratio of 20:1, using straw and cottonseed meal as amendments. Mixtures were then inoculated with Salmonella and Listeria monocytogenes labeled with green fluorescent protein at initial populations of ca. 107 CFU/g. Three replicate trials of each treatment were conducted. Temperatures within the bioreactors were recorded at 30-min intervals, and duplicate samples were withdrawn daily from two sampling locations within the bioreactor. Significant regression models were derived relating decreases in pathogen populations to the degree of heat generated in the mixture (cumulative heat) and the pH of the mixture on the day before the pathogen losses were calculated (P < 0.0002). Although pathogens in swine manure compost mixtures were inactivated by the third day of composting, very little heat was generated in these mixtures, which were characterized by significantly higher levels of volatile acids compared with the other two compost mixtures. Therefore, volatile acids could help achieve pathogen inactivation when temperatures are too low such as when heat is lost too quickly at the surface of static compost piles or during winter composting.

scholarly journals A Predictive Model for Survival of Escherichia coli O157:H7 and Generic E. coli in Soil Amended with Untreated Animal Manure

Risk Analysis ◽  
2020 ◽  
Vol 40 (7) ◽  
pp. 1367-1382 ◽  
Author(s):  
Hao Pang ◽  
Amir Mokhtari ◽  
Yuhuan Chen ◽  
David Oryang ◽  
David T. Ingram ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Predictive Model ◽  
Animal Manure ◽  
Escherichia Coli O157 ◽  
Untreated Animal ◽  
E Coli

Ammonia sanitization of blackwater for safe use as fertilizer

2015 ◽  
Vol 71 (5) ◽  
pp. 795-800 ◽  
Author(s):  
Jörgen Fidjeland ◽  
Sven-Erik Svensson ◽  
Björn Vinnerås
Keyword(s):  
Escherichia Coli ◽  
Treatment Time ◽  
Escherichia Coli O157 ◽  
Storage Facility ◽  
Egg Viability ◽  
Pathogen Inactivation ◽  
E Coli ◽  
Available Nutrients ◽  
Manure Slurry ◽  
The Impact

Source-separated blackwater from low-flush toilets contains plant-available nutrients and can be used as a fertilizer. The aim of the study was to evaluate the impact on pathogen inactivation when treating blackwater with urea and/or lime. Blackwater was spiked with Salmonella typhimurium, Escherichia coli O157, Enterococcus faecalis, and Ascaris suum eggs, and treated with urea and/or lime in concentrations up to 0.1% w/w. The bottles were kept in a storage facility (manure slurry tank) for 102 days while monitoring the pathogen concentrations. The treatment time needed to meet the requirement for Salmonella and E. coli reduction could be reduced at least six-fold. The enterococci were more persistent, and only the highest treatment doses had a significantly higher inactivation than the controls. The Ascaris egg viability was only reduced by around 50%, so higher urea/lime doses and/or longer treatment times are required to fulfill the treatment requirements of 3 log10 reductions of parasite eggs.

Dynamic Effects of Free Chlorine Concentration, Organic Load, and Exposure Time on the Inactivation of Salmonella, Escherichia coli O157:H7, and Non-O157 Shiga Toxin–Producing E. coli†

2013 ◽  
Vol 76 (3) ◽  
pp. 386-393 ◽  
Author(s):  
CANGLIANG SHEN ◽  
YAGUANG LUO ◽  
XIANGWU NOU ◽  
QIN WANG ◽  
PATRICIA MILLNER
Keyword(s):  
Escherichia Coli ◽  
Organic Matter ◽  
Exposure Time ◽  
Shiga Toxin ◽  
Contact Time ◽  
Organic Load ◽  
Escherichia Coli O157 ◽  
Pathogen Inactivation ◽  
Dynamic Effects ◽  
E Coli

This study evaluated the dynamic effects of free-chlorine (FC) concentration, contact time, and organic load on the inactivation of Salmonella, Escherichia coli O157:H7, and non-O157 Shiga toxin–producing E. coli (STEC) in suspension. Bacterial cells from four strains each of Salmonella, E. coli O157:H7, and non-O157 STEC were inoculated separately or as a multistrain cocktail into solutions with varying FC concentrations. Lettuce or tomato extract was used to simulate the organic matter present during commercial fresh and fresh-cut produce wash operations. After exposure to FC for various lengths of time, the bacterial survival and water-quality changes were determined. In the absence of organic matter in a wash solution, pathogen inactivation is primarily a function of initial FC concentration (P < 0.0001), exposure time (P < 0.0001), and pathogen strains (P < 0.0001). In general, an over 4.5-log CFU/ml pathogen reduction was found after exposure to >0.5 mg/liter FC for over 30 s, or to >1.0 mg/liter FC for over 5 s. When the combination of FC concentration and contact time were less than or equal to the above conditions, survival of pathogens was strain dependant and ranked as: Salmonella > E. coli O157:H7 > non-O157 STEC. When organic matter was present in the wash solution, pathogen inactivation efficacy was specifically dependent on the residual FC concentration, which directly relates to both the initial FC concentration and the organic load. Prevention of pathogen survival in chlorinated produce wash solutions can be achieved by maintaining sufficient FC concentration and reducing the accumulation of organic matter.

Inactivation of Pathogens during Aerobic Composting of Fresh and Aged Dairy Manure and Different Carbon Amendments

2014 ◽  
Vol 77 (11) ◽  
pp. 1911-1918 ◽  
Author(s):  
MARILYN C. ERICKSON ◽  
JEAN LIAO ◽  
XIUPING JIANG ◽  
MICHAEL P. DOYLE
Keyword(s):  
C:N Ratio ◽  
Heat Exposure ◽  
Ammonia Concentration ◽  
Dairy Manure ◽  
Physical Parameters ◽  
Pathogen Inactivation ◽  
Factors Affecting ◽  
Initial Carbon ◽  
Peanut Hulls ◽  
Pathogen Reduction

Two separate studies were conducted to address the condition and the type of feedstocks used during composting of dairy manure. In each study, physical (temperature), chemical (ammonia, volatile acids, and pH), and biological (Salmonella, Listeria monocytogenes, and Escherichia coli O157:H7) parameters were monitored during composting in bioreactors to assess the degree to which they were affected by the experimental variables and, ultimately, the ability of the chemical and physical parameters to predict the fate of pathogens during composting. Compost mixtures that contained either aged dairy manure or pine needles had reduced heat generation; therefore, pathogen reduction took longer than if fresh manure or carbon amendments of wheat straw or peanut hulls were used. Based on regression models derived from these results, ammonia concentration, in addition to heat, were the primary factors affecting the degree of pathogen inactivation in compost mixtures formulated to an initial carbon-nitrogen (C:N) ratio of 40:1, whereas, the pH of the compost mixture along with the amount of heat exposure were most influential in compost mixtures formulated to an initial C:N ratio of 30:1. Further studies are needed to validate these models so that additional criteria in addition to time and temperature can be used to evaluate the microbiological safety of composted manures.

A Model Study of Escherichia coli O157:H7 Survival in Fermented Dry Sausages—Influence of Inoculum Preparation, Inoculation Procedure, and Selected Process Parameters

2003 ◽  
Vol 66 (12) ◽  
pp. 2267-2275 ◽  
Author(s):  
FADIA NAIM ◽  
SERGE MESSIER ◽  
LINDA SAUCIER ◽  
GABRIEL PIETTE
Keyword(s):  
Escherichia Coli ◽  
Escherichia Coli O157 ◽  
Pathogen Inactivation ◽  
Fermented Sausage ◽  
E Coli ◽  
Fermentation Temperature ◽  
Model Study ◽  
Inoculation Procedure ◽  
Acidic Conditions ◽  
Inoculum Preparation

The influence of inoculum preparation, inoculation level, and inoculation procedure on Escherichia coli O157:H7 inactivation during the manufacture of fermented sausage was evaluated in a model study. Prior growth in glucose-enrichedtryptone soya broth, which provided exposure to mildly acidic conditions (pH 4.8), had no effect on the later survival of E. coli O157: H7 strains 5-1 and ATCC 43894 under extremely acidic conditions (pH 2), but the same strains became sensitive to acidity after 7 days of incubation on the surface of refrigerated beef (as per the normal contamination route from slaughter to further processing). In subsequent sausage production trials, the extent of destruction observed for E. coli O157:H7 strains F-90, 5-1, and ATCC 43894 inoculated directly into the meat batter was unchanged when the inoculation level was decreased from 7.3 to 4.7 log CFU/g, but the level of inactivation was ca. 1 log higher when the surfaces of beef cuts, rather than the batter, were inoculated 7 days prior to processing. Regardless of processing conditions (fermentation to a pH of ≤5.0 at 24 or 37°C, drying at 14°C to a water activity [aw] value of 0.91 or 0.79), strains F-90, 5-1, and ATCC 43894 showed similar survival capacities during the manufacture of sausage. A ~2-log reduction in pathogen numbers was generally obtained after samples were dried to an aw of 0.91, irrespective of fermentation temperature. The addition of a 5-day predrying holding stage at the fermentation temperature significantly (P < 0.05) increased pathogen inactivation when fermentation was carried out at 37°C (but not when it was carried out at 24°C). However, significant pathogen reductions (4 to 5 log CFU/g) were achieved only for extensively dried products (aw = 0.79).

Reduction of Escherichia coli O157:H7 and Salmonella enterica Serovar Enteritidis in Chicken Manure by Larvae of the Black Soldier Fly

2004 ◽  
Vol 67 (4) ◽  
pp. 685-690 ◽  
Author(s):  
MARILYN C. ERICKSON ◽  
MAHBUB ISLAM ◽  
CRAIG SHEPPARD ◽  
JEAN LIAO ◽  
MICHAEL P. DOYLE
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Salmonella Enteritidis ◽  
Feeding Activity ◽  
Chicken Manure ◽  
Escherichia Coli O157 ◽  
Pathogen Inactivation ◽  
Salmonella Enterica Serovar Enteritidis ◽  
E Coli ◽  
Fly Larvae

Green fluorescent protein–labeled Escherichia coli O157:H7 and Salmonella enterica serovar Enteritidis were inoculated at 107 CFU/g into cow, hog, or chicken manure. Ten- or 11-day-old soldier fly larvae ( Hermetia illucens L.) (7 to 10 g) were added to the manure and held at 23, 27, or 32°C for 3 to 6 days. Soldier fly larvae accelerated inactivation of E. coli O157: H7 in chicken manure but had no effect in cow manure and enhanced survival in hog manure. The initial pH values of the hog and chicken manure were 6.0 to 6.2 and 7.4 to 8.2, respectively, and it is surmised that these conditions affected the stability of the larval antimicrobial system. Reductions of E. coli O157:H7 populations in chicken manure by larvae were affected by storage temperature, with greater reductions in samples held for 3 days at 27 or 32°C than at 23°C. Pathogen inactivation in chicken manure by larvae was not affected by the indigenous microflora of chicken manure, because Salmonella Enteritidis populations in larvae-treated samples were approximately 2.5 log lower than control samples without larvae when either autoclaved or nonautoclaved chicken manure was used as the contaminated medium during 3 days of storage. Extending the storage time to 6 days, larvae again accelerated the reduction in Salmonella Enteritidis populations in chicken manure during the first 4 days of storage; however, larvae became contaminated with the pathogen. After 2 days of feeding on contaminated manure, Salmonella Enteritidis populations in larvae averaged 3.3 log CFU/g. Populations decreased to 1.9 log CFU/g after 6 days of exposure to contaminated chicken manure; however, the absence of feeding activity by the maggots in later stages of storage may be responsible for the continued presence of Salmonella Enteritidis in larvae. Transfer of contaminated larvae to fresh chicken manure restored feeding activity but led to cross-contamination of the fresh manure.

Survival and Persistence of Nonpathogenic Escherichia coli and Attenuated Escherichia coli O157:H7 in Soils Amended with Animal Manure in a Greenhouse Environment

2016 ◽  
Vol 79 (6) ◽  
pp. 913-921 ◽  
Author(s):  
MANAN SHARMA ◽  
PATRICIA D. MILLNER ◽  
FAWZY HASHEM ◽  
MARY CAMP ◽  
CELIA WHYTE ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Sandy Loam ◽  
Dry Weight ◽  
Animal Manure ◽  
Dairy Manure ◽  
Escherichia Coli O157 ◽  
Silt Loam ◽  
Amended Soils ◽  
Factors Affecting ◽  
E Coli

ABSTRACT Animal manure provides benefits to agriculture but may contain pathogens that contaminate ready-to-eat produce. U.S. Food and Drug Administration standards include 90- or 120-day intervals between application of manure and harvest of crop to minimize risks of pathogen contamination of fresh produce. Data on factors affecting survival of Escherichia coli in soils under greenhouse conditions are needed. Three separate studies were conducted to evaluate survival of nonpathogenic E. coli (gEc) and attenuated E. coli O157:H7 (attO157) inoculated at either low (4 log CFU/ml) or high (6 log CFU/ml) populations over 56 days. Studies involved two pot sizes (small, 398 cm3; large, 89 liters), three soil types (sandy loam, SL; clay loam, CL; silt loam, SIL), and four amendments (poultry litter, PL; dairy manure liquids, DML; horse manure, HM; unamended). Amendments were applied to the surface of the soil in either small or large containers. Study 1, conducted in regularly irrigated small containers, showed that populations of gEc and attO157 (2.84 to 2.88 log CFU/g) in PL-amended soils were significantly (P < 0.05) greater than those in DML-amended (0.29 to 0.32 log CFU/g [dry weight] [gdw]) or unamended (0.25 to 0.28 log CFU/gdw) soils; soil type did not affect E. coli survival. Results from study 2, in large pots with CL and SIL, showed that PL-amended soils supported significantly higher attO157 and gEc populations compared with HM-amended or unamended soils. Study 3 compared results from small and large containers that received high inoculum simultaneously. Overall, in both small and large containers, PL-amended soils supported higher gEc and attO157 populations compared with HM-amended and unamended soils. Populations of attO157 were significantly greater in small containers (1.83 log CFU/gdw) than in large containers (0.65 log CFU/gdw) at week 8, perhaps because small containers received more regular irrigation than large pots. Regular irrigation of small pots may have affected E. coli persistence in manure-amended soils. Overall, PL-amended soils in both small and large containers supported E. coli survival at higher populations compared with DML-, HM-, or unamended soils.

Inactivation of Escherichia coli O157:H7 and Salmonella by Gamma Irradiation of Alfalfa Seed Intended for Production of Food Sprouts†

2003 ◽  
Vol 66 (2) ◽  
pp. 175-181 ◽  
Author(s):  
DONALD W. THAYER ◽  
KATHLEEN T. RAJKOWSKI ◽  
GLENN BOYD ◽  
PETER H. COOKE ◽  
DOUGLAS S. SOROKA
Keyword(s):  
Escherichia Coli ◽  
Moisture Content ◽  
Water Activity ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Alfalfa Seed ◽  
D Values ◽  
Different Sources ◽  
D Value ◽  
Alfalfa Seeds

Inonizing irradiation was determined to be a suitable method for the inactivation of Salmonella and Escherichia coli O157:H7 on alfalfa seed to be used in the production of food sprouts. The radiation D (dose resulting in a 90% reduction of viable CFU) values for the inactivation of Salmonella and E. coli O157:H7 on alfalfa seeds were higher than the D-values for their inactivation on meat or poultry. The average D-value for the inactivation of Salmonella on alfalfa seeds was 0.97 ± 0.03 kGy; the D-values for cocktails of meat isolates and for vegetable-associated isolates were not significantly different. The D-values for nonoutbreak and outbreak isolates of E. coli O157:H7 on alfalfa seeds were 0.55 ± 0.01 and 0.60 ± 0.01 kGy, respectively. It was determined that the relatively high D-values were not due to the low moisture content or the low water activity of the seed. The D-values for Salmonella on alfalfa seeds from two different sources did not differ significantly, even though there were significant differences in seed size and water activity. The increased moisture content of the seed after artificial inoculation did not significantly alter the D-value for the inactivation of Salmonella. The results of this study demonstrate that 3.3- and 2-log inactivations can be achieved with a 2-kGy dose of ionizing radiation, which will permit satisfactory commercial yields of sprouts from alfalfa seed contaminated with E. coli O157:H7 and Salmonella, respectively.

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