scholarly journals Survival and Persistence of Foodborne Pathogens in Manure-Amended Soils and Prevalence on Fresh Produce in Certified Organic Farms: A Multi-Regional Baseline Analysis

2021 ◽  
Vol 5 ◽  
Author(s):  
Thais De Melo Ramos ◽  
Michele T. Jay-Russell ◽  
Patricia D. Millner ◽  
Jerome Nicholas Baron ◽  
James Stover ◽  
...  

Biological soil amendments of animal origin (BSAAOs), including untreated (e.g., raw or aged manure, or incompletely composted manure) and treated animal products (e.g., compost), are used for crop production and as part of soil health management. Application of BSAAO's must be done cautiously, as raw manure commonly contains enteric foodborne pathogens that can potentially contaminate edible produce that may be consumed without cooking. USDA National Organic Program (NOP) certified production systems follow the 90-or 120-day interval standards between applications of untreated BSAAOs and crop harvest, depending on whether the edible portions of the crops are in indirect or direct contact with the soil, respectively. This study was conducted to evaluate the survival of four foodborne pathogens in soils amended with BSAAOs and to examine the potential for bacterial transfer to fresh produce harvested from USDA NOP certified organic farms (19) from four states. Only 0.4% (2/527) of produce samples were positive for L. monocytogenes. Among the untreated manure and compost samples, 18.0% (42/233) were positive for at least one of the tested and culturable bacterial foodborne pathogens. The prevalence of non-O157 STEC and Salmonella in untreated manure was substantially > that of E. coli O157:H7 and L. monocytogenes. Of the 2,461 soil samples analyzed in this study, 12.9% (318) were positive for at least one pathogen. In soil amended with untreated manure, the prevalence of non-O157 STEC [7.7% (190) and L. monocytogenes (5.0% (122), was > that of Salmonella (1.1% (26)] or E. coli O157 [0.04% (1)]. Foodborne pathogen prevalence in the soil peaked after manure application and decreased significantly 30 days post-application (dpa). However, non-O157 STEC and L. monocytogenes were recovered from soil samples after 90 and 120 dpa. Results indicate that produce contamination by tested foodborne pathogens was infrequent, but these data should not be generalized outside of the specific wait-time regulations for organic crop production and the farms studied. Moreover, other sources of contamination, e.g., irrigation, wildlife, environmental conditions, cropping and management practices, should be considered. This study also provides multi-regional baseline data relating to current NOP application intervals and development of potential risk mitigation strategies to reduce pathogen persistence in soils amended with BSAAOs. These findings contribute to filling critical data gaps concerning occurrence of fecal pathogens in NOP-certified farming systems used for production of fresh produce in different US regions.

Author(s):  
Marie Limoges ◽  
Deborah A. Neher ◽  
Thomas R. Weicht ◽  
Patricia D. Millner ◽  
Manan Sharma ◽  
...  

Composted or heat-treated Biological Soil Amendments of Animal Origin (BSAAO) can be added to soils to provide nutrients for fresh produce. These products lower the risk of pathogen contamination of fresh produce when compared with use of untreated BSAAO; however, meteorological conditions, geographic location, and soil properties can influence the presence of pathogenic bacteria, or their indicators (e.g., generic E. coli) and allow potential for produce contamination. Replicated field plots of loamy or sandy soils were tilled and amended with dairy manure compost (DMC), poultry litter compost (PLC), or no compost (NoC) over two different field seasons, and non-composted heat-treated poultry pellets (HTPP) during the second field season. Plots were inoculated with a three-strain cocktail of rifampicin-resistant E. coli (rE.coli) at levels of 8.7 log CFU/m2. Direct plating and most probable number (MPN) methods measured the persistence of rE.coli and Listeria spp. in plots through 104 days post-inoculation. Greater survival of rE. coli was observed in PLC plots in comparison to DMC plots and NoC plots during year 1 (P < 0.05). Similar trends were observed for year 2, where rE. coli survival was also greater in HTPP amended plots (P < 0.05). Survival of rE. coli was dependent on soil type, where water potential and temperature were significant covariables. Listeria spp. were found in NoC plots, but not in plots amended with HTPP, PLC or DMC. Radish data demonstrate that PLC treatment promoted the greatest level of rE.coli translocation when compared to DMC and NoC treatments (P  < 0.05). These results are consistent with findings from studies conducted in other regions of the US and informs Northeast produce growers that composted and non-composted poultry-based BSAAO supports greater survival of rE. coli in field soils. This result has the potential to impact the food safety risk of edible produce grown in BSAAO amended soils as a result of pathogen contamination.


2020 ◽  
Vol 367 (1) ◽  
Author(s):  
Bernhard Merget ◽  
Ulrich Dobrindt ◽  
Ken J Forbes ◽  
Norval J C Strachan ◽  
Fiona Brennan ◽  
...  

ABSTRACT Foods of plant origin are recognised as a major source of foodborne pathogens, in particular for Shigatoxigenic Escherichia coli (STEC). Most work for STEC and plant-based fresh produce has focused on the most prevalent outbreak serogroup, O157. However, non-O157 STEC is an emerging hazard, and as such it is important to characterise aspects within this group that reflect their ability to colonise alternative hosts and habitats relevant to horticultural production. Growth kinetics were quantified for a diverse set of clinical enterohaemorrhagic E. coli isolates in extracts made from different tissues of spinach, lettuce or sprouted seeds, or from soil, to represent association with ready-to-eat fresh produce production. For leafy vegetables, spinach apoplast supported the fastest rates of growth and lettuce root extracts generated the slowest growth rates. Growth rates were similar for the majority of isolates in fenugreek or alfalfa sprouted seed extracts. Monosaccharides were the major driver of bacterial growth. No correlations were found for growth rates between different serotypes or for Shigatoxin gene carriage. Thus, growth rates varied in a plant-dependent and isolate-dependent manner, for all plant or soil extracts tested, indicative of isolate-specific differences in metabolic flexibility. These findings are relevant for risk assessment of non-O157 STEC.


2020 ◽  
Vol 83 (11) ◽  
pp. 1934-1940
Author(s):  
ALDA F. A. PIRES ◽  
JAMES STOVER ◽  
ESTHER KUKIELKA ◽  
VIKTORIA HAGHANI ◽  
PEIMAN AMINABADI ◽  
...  

ABSTRACT As the number of farmers' markets and other direct-to-consumer marketing channels increases, it is crucial to understand the potential risks associated with consuming directly marketed animal products and fresh produce. The overall aim of this project was to assess the prevalence of Salmonella and Escherichia coli in animal products and produce sold at farmers' markets in Northern California and to evaluate the food safety risks associated with consuming meat (e.g., beef, pork, and poultry) and fresh produce purchased from farmers' markets. Animal products and produce were purchased from a total of 44 certified farmers' markets in Northern California. Salmonella was found in 6 (1.8%) of 338 animal products and in 0 (0%) of 128 produce samples; E. coli was found in 40 (31.3%) of 128 fresh produce samples. E. coli concentration in produce ranged from 0 to 2.96, with an overall average of 0.13 log (most probable number + 1)/100 mL. Salmonella isolates were resistant to nalidixic acid and tetracycline. The results from this study highlight the need for further training on mitigation strategies to reduce contamination of animal products and fresh produce by foodborne pathogens. HIGHLIGHTS


2007 ◽  
Vol 70 (4) ◽  
pp. 828-834 ◽  
Author(s):  
D. T. INGRAM ◽  
P. D. MILLNER

Compost tea (CT) is an unheated on-farm infusion of compost used as a spray or soil drench to promote plant growth and control foliar and root diseases. Because food safety involves all aspects from farm to fork, CT should meet basic microbiological criteria for water quality. This report describes the effects of two CT production processes, aerated and nonaerated, on growth and survival of foodborne pathogens and fecal coliforms. Seven commercially available nutrients used to supplement CT were tested individually and in combination for their effects on the growth of Escherichia coli and Salmonella. Compost containing 101 to 103 CFU/g initial concentrations of E. coli O157:H7 and Salmonella Enteritidis were used to assess growth and survival responses to aerated CT (36-h preparations) and nonaerated CT (8.5-day preparations). Pathogen and fecal coliform populations were undetectable by 8.5 days in nonaerated CT without nutrient supplements. E. coli O157:H7 decreased to below detection levels in aerated CT at 36 h without the use of supplements. In contrast, the addition of commercially formulated mixtures or combinations of nutrient supplements resulted in growth of E. coli O157: H7, Salmonella, and fecal coliforms by 1 to 4 log CFU/g in both aerated and nonaerated CT. When nutrient supplements were added, aerated CT sustained higher concentrations of E. coli O157:H7, Salmonella, and fecal coliforms than did nonaerated CT. Thus, addition of supplements supports growth of human pathogens from very low initial concentrations in both aerated and nonaerated CT and should be avoided when CT is used on fresh produce.


Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1391
Author(s):  
Rebecca L. Bell ◽  
Julie A. Kase ◽  
Lisa M. Harrison ◽  
Kannan V. Balan ◽  
Uma Babu ◽  
...  

Water is vital to agriculture. It is essential that the water used for the production of fresh produce commodities be safe. Microbial pathogens are able to survive for extended periods of time in water. It is critical to understand their biology and ecology in this ecosystem in order to develop better mitigation strategies for farmers who grow these food crops. In this review the prevalence, persistence and ecology of four major foodborne pathogens, Shiga toxin-producing Escherichia coli (STEC), Salmonella, Campylobacter and closely related Arcobacter, and Listeria monocytogenes, in water are discussed. These pathogens have been linked to fresh produce outbreaks, some with devastating consequences, where, in a few cases, the contamination event has been traced to water used for crop production or post-harvest activities. In addition, antimicrobial resistance, methods improvements, including the role of genomics in aiding in the understanding of these pathogens, are discussed. Finally, global initiatives to improve our knowledge base of these pathogens around the world are touched upon.


2009 ◽  
Vol 72 (2) ◽  
pp. 415-420 ◽  
Author(s):  
V. M. BOHAYCHUK ◽  
R. W. BRADBURY ◽  
R. DIMOCK ◽  
M. FEHR ◽  
G. E. GENSLER ◽  
...  

Previously there was no available information on the levels of indicator bacteria and the prevalence of pathogens in fresh produce grown in Alberta, Canada. Baseline information on the occurrence and levels of Escherichia coli and the prevalence of foodborne pathogens in selected produce items available to consumers from farmers' and public markets in two large urban centers and surrounding areas in Alberta was obtained. A total of 10 large markets with between 1 and 12 produce vendors and 26 small markets with between 1 and 6 produce vendors were sampled from 21 June to 7 October 2007. Lettuce (128 samples), spinach (59 samples), tomatoes (120 samples), carrots (206 samples), green onions (129 samples), and strawberries (31 samples) were analyzed for E. coli, Salmonella, E. coli O157:H7, and Campylobacter spp. Lettuce, spinach, green onion, and strawberry samples were also tested for the presence of Cryptosporidium spp. Information on whether produce was grown using organic or conventional practices was obtained from the produce vendors. E. coli was isolated from 8.2% of the samples that included lettuce, spinach, carrots, and green onions. The bacterial counts ranged from <0.48 to >3.04 Log most probable number per g. E. coli was not isolated from tomatoes or strawberries. The percentage of positive samples ranged from 4.4% for carrots to 27.1% for spinach. Salmonella, E. coli O157:H7, and Campylobacter spp. were not isolated from any of the samples. Cryptosporidium was identified by PCR in one sample of spinach (0.6% of the samples).


2004 ◽  
Vol 67 (5) ◽  
pp. 894-900 ◽  
Author(s):  
AVIK MUKHERJEE ◽  
DORINDA SPEH ◽  
ELIZABETH DYCK ◽  
FRANCISCO DIEZ-GONZALEZ

Microbiological analyses of fresh fruits and vegetables produced by organic and conventional farmers in Minnesota were conducted to determine the coliform count and the prevalence of Escherichia coli, Salmonella, and E. coli O157:H7. A total of 476 and 129 produce samples were collected from 32 organic and 8 conventional farms, respectively. The samples included tomatoes, leafy greens, lettuce, green peppers, cabbage, cucumbers, broccoli, strawberries, apples, and seven other types of produce. The numbers of fruits and vegetables was influenced by their availability at participating farms and varied from 11 strawberry samples to 108 tomato samples. Among the organic farms, eight were certified by accredited agencies and the rest reported the use of organic practices. All organic farms used aged or composted animal manure as fertilizer. The average coliform counts in both organic and conventional produce were 2.9 log most probable number per g. The percentages of E. coli–positive samples in conventional and organic produce were 1.6 and 9.7%, respectively. However, the E. coli prevalence in certified organic produce was 4.3%, a level not statistically different from that in conventional samples. Organic lettuce had the largest prevalence of E. coli (22.4%) compared with other produce types. Organic samples from farms that used manure or compost aged less than 12 months had a prevalence of E. coli 19 times greater than that of farms that used older materials. Serotype O157:H7 was not detected in any produce samples, but Salmonella was isolated from one organic lettuce and one organic green pepper. These results provide the first microbiological assessment of organic fruits and vegetables at the farm level.


Author(s):  
Seungjun Lee ◽  
Chulkyoon Mok ◽  
Jiyoung Lee

Once pathogens are internalized in fresh produce, they pose a challenging food safety issue since they are not effectively inactivated by conventional rinsing or sanitization. To protect food safety and public health, the objectives were to examine internalized levels of foodborne pathogens in different types of fresh produce and to investigate the effectiveness of photocatalytically enhanced inactivation of internalized pathogens in fresh produce using UV irradiation with titanium dioxide (TiO 2 ). For this, green fluorescent protein-labeled S. Typhimurium and E. coli O157:H7 were inoculated on the leaf surface of four types of fresh produce (~10 8 CFU (colony-forming unit)/leaf) and varying concentrations of TiO 2 suspension (0.50, 0.75, 1.00, 1.25, and 1.50 µg/ml)) were applied to the surface of contaminated leaves. Depending on the nature of each vegetable, the internalized bacterial level differed (log 2 – 5 CFU/g of leaf). When UV irradiation (6,000 J/m 2 ) was applied, the internalized S. Typhimurium and E. coli levels were reduced by 0.8 – 2.4 log CFU/leaf and was with TiO 2 , the reduction was 1.1 – 3.7 log CFU/leaf. The inactivation efficiency increased as the TiO 2 concentration (up to 1.50 μg/leaf). These results indicate that the TiO 2 application enhanced the photocatalytic inactivation of internalized foodborne pathogens. The application of TiO2 would be most practical before UV irradiation and before distributing the produce. This study established a platform for future research on the inactivation of various internalized pathogens for protecting public health and scaling up fresh produce treatments by the food industry.


1997 ◽  
Vol 35 (11-12) ◽  
pp. 351-357 ◽  
Author(s):  
R. Rothmaier ◽  
A. Weidenmann ◽  
K. Botzenhart

Isolates (50) of E. coli obtained from liquid manure (20 bovine, 20 porcine) were genotyped using random amplified polymorphic DNA (RAPD). Typing revealed 9 and 14 different strains in bovine and porcine liquid manure respectively with no strains in common. One porcine strain, showing a simple RAPD pattern, was subcultured and spread on a test field (1.5l/m2 at 1010 cfu/l) in a drinking water protection zone with loamy to sandy sediments in the Donauried area, Baden-Wurttemberg. Soil samples and groundwaters were collected at monthly intervals October 1994 – June 1995 during which 114 E. coli isolates were recovered. The first occurrence and maximum concentration of E. coli in soil samples taken from more than 20cm depth was in January 1995, declining rapidly with depth and time. All isolates from soil and only one from groundwater showed the RAPD pattern of the spread E. coli strain. The results could not demonstrate a severe negative impact of the spreading of liquid manure on the bacteriological quality of the groundwater in the given geological situation. The distinct strain patterns found in different kinds of liquid manure suggest that genotyping of E. coli by RAPD may be an adequate tool for tracing sources of faecal contamination.


2017 ◽  
Vol 4 (04) ◽  
Author(s):  
ABDUR RAZZAK ◽  
PARSA SANJANA ◽  
BELAL HOSSAIN ◽  
DEBJIT ROY ◽  
BIDHAN CHANDRA NATH

The study was conducted at Ashuganj-Polash agro-irrigation project (APAIP), Brahmanbaria,aim to determine the chemical properties of power plant disposal water and to assess its suitability for irrigation. Initial soil samples (before irrigating crop field) and final soil samples (after crop harvesting) were collected. During irrigation ten water samples (six from crop field and four from irrigation canals) were collected for analysis. All soil samples were analyzed in Humboldt soil testing laboratory and water samples in bio-chemistry laboratory of Bangladesh Agricultural University and compared to FAO irrigation standard. Results show thatthe sodium absorption ratio (SAR) (0.53 to 0.88), residual sodium bi-carbonate (0.8 to 1.3meq L-1), Kelly’s ratio (0.31 to 0.6) and total hardness (85 to 150) found in normal range and largely suitable for irrigation. Soluble sodium percentage values found in satisfactory (20.26 to 41.1) level and magnesium absorption (57.1 to 76.4) found unsuitable for irrigation. Statistically similar value of pH, EC, total nitrogen, organic carbon, calcium, magnesium and phosphorus in initial and final soil sample were observed. But potassium and sulfur value reduced in final soil sample from initial soil. The water samples fall within the permissible limit and found suitable for crop production


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