scholarly journals Effects of Plant Age and Root Damage on Internalization of Shiga Toxin-Producing Escherichia coli in Leafy Vegetables and Herbs

Horticulturae ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 68
Author(s):  
Yi-Ju Wang ◽  
Amanda J. Deering ◽  
Hye-Ji Kim
Keyword(s):  
Escherichia Coli ◽  
Plant Species ◽  
Shiga Toxin ◽  
Production Systems ◽  
Plant Age ◽  
Leafy Vegetables ◽  
Root Damage ◽  
Hygiene Practices ◽  
Hydroponic Systems ◽  
Stx1 Gene

Our previous study reported that fresh produce grown in aquaponic and hydroponic systems can pose potential food safety hazards due to an accidental introduction of contaminated fish and cross-contamination between the systems. In this study, we examined the effects of plant species and age on the likelihood and level of internalization of Shiga toxin-producing Escherichia coli (STEC) in aquaponic and hydroponic systems. Four plant species, basil (Ocimum basilicum L. cv. Genovese), cilantro (Coriandrum Sativum L.), lettuce (Lactuca sativa cv. Cherokee), and kale (Brassica oleracea var. sabellica), received root damage treatment as seedlings before transplanting or mature plants at three weeks after transplanting by cutting off 1-cm tips of one-third of the roots. Enrichments and selective media were used for the isolation, and presumptive positive colonies were confirmed by PCR for the presence of stx1 gene in plant tissues, recirculating water, and fish feces collected at four weeks after transplanting. In hydroponic systems, STEC was found neither in the solution nor in the roots and leaves of all four plant species, possibly through improved sanitation and hygiene practices. However, consistent with our previous findings, STEC was found in the water, on the plant roots, and in the fish feces in aquaponic systems, even after thorough sanitation prior to the study. Regardless of plant age, STEC was internalized in the roots of all plant species when the roots were damaged, but there was no difference in the degree of internalization with STEC among plant species. STEC was present in the leaves only when seedlings received root damage treatment and were grown to maturity, indicating that root damage allows STEC to internalize in the roots within a week, but a longer period is required for STEC to internalize into the leaves. We concluded that root damage on seedlings can cause the internalization of E. coli O157:H7 in the edible parts of leafy vegetables and herbs in soilless production systems.

scholarly journals Detection of virulence factors and antimicrobial resistance patterns in shiga toxin-producing Escherichia coli isolates from sheep

2015 ◽  
Vol 35 (9) ◽  
pp. 775-780 ◽  
Author(s):  
Marcos R.A. Ferreira ◽  
Talícia dos S. Silva ◽  
Ariel E. Stella ◽  
Fabricio R. Conceição ◽  
Edésio F. dos Reis ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Virulence Factors ◽  
Shiga Toxin ◽  
Resistance Profile ◽  
Antimicrobial Resistance Profile ◽  
Healthy Sheep ◽  
Resistance Patterns ◽  
Group A ◽  
Stx1 Gene

Abstract: In order to detect virulence factors in Shiga toxin-producing Escherichia coli (STEC) isolates and investigate the antimicrobial resistance profile, rectal swabs were collected from healthy sheep of the races Santa Inês and Dorper. Of the 115 E. coli isolates obtained, 78.3% (90/115) were characterized as STEC, of which 52.2% (47/90) carried stx1 gene, 33.3% (30/90) stx2 and 14.5% (13/90) both genes. In search of virulence factors, 47.7% and 32.2% of the isolates carried the genes saa and cnf1. According to the analysis of the antimicrobial resistance profile, 83.3% (75/90) were resistant to at least one of the antibiotics tested. In phylogenetic classification grouped 24.4% (22/90) in group D (pathogenic), 32.2% (29/90) in group B1 (commensal) and 43.3% (39/90) in group A (commensal). The presence of several virulence factors as well as the high number of multiresistant isolates found in this study support the statement that sheep are potential carriers of pathogens threatening public health.

scholarly journals Outbreaks attributed to fresh leafy vegetables, United States, 1973–2012

2015 ◽  
Vol 143 (14) ◽  
pp. 3011-3021 ◽  
Author(s):  
K. M. HERMAN ◽  
A. J. HALL ◽  
L. H. GOULD
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
Disease Control ◽  
Shiga Toxin ◽  
Federal Agencies ◽  
Local State ◽  
Leafy Vegetable ◽  
Leafy Vegetables ◽  
High Profile ◽  
Control And Prevention

SUMMARYLeafy vegetables are an essential component of a healthy diet; however, they have been associated with high-profile outbreaks causing severe illnesses. We reviewed leafy vegetable-associated outbreaks reported to the Centers for Disease Control and Prevention between 1973 and 2012. During the study period, 606 leafy vegetable-associated outbreaks, with 20 003 associated illnesses, 1030 hospitalizations, and 19 deaths were reported. On average, leafy vegetable-associated outbreaks were larger than those attributed to other food types. The pathogens that most often caused leafy vegetable-associated outbreaks were norovirus (55% of outbreaks with confirmed aetiology), Shiga toxin-producing Escherichia coli (STEC) (18%), and Salmonella (11%). Most outbreaks were attributed to food prepared in a restaurant or catering facility (85%). An ill food worker was implicated as the source of contamination in 31% of outbreaks. Efforts by local, state, and federal agencies to control leafy vegetable contamination and outbreaks should span from the point of harvest to the point of preparation.

scholarly journals Isolation of Shiga toxin-producing strains of Escherichia coli from beef and swine carcasses and the characterization of their genes

2018 ◽  
Vol 9 (2) ◽  
pp. 275-780 ◽  
Author(s):  
O. М. Berhilevych ◽  
V. V. Kasianchuk ◽  
O. M. Deriabin ◽  
M. D. Kukhtyn
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Raw Material ◽  
Animal Origin ◽  
E Coli ◽  
Food Of Animal Origin ◽  
Beef Carcasses ◽  
Positive Isolate ◽  
Stx1 Gene ◽  
Beef Carcass

Escherichia coli is part of the normal microflora of the intestinal tract of humans and warm-blooded animals, but its presence in raw material and food of animal origin is considered as fecal contamination and can be very dangerous for consumers. The determination of the number of E. coli in raw material and food is important because among them can be pathogenic strains. The most dangerous strains are considered enterohemorrhagic E. coli as a causative agent of severe bloody diarrhea and hemorrhagic uremic syndrome in humans through the production of Shiga-toxin, which is the main virulence factor, responsible for disease. The aim of this study was to identify the prevalence of Shiga toxin-producing strains of E. coli (STEC) from swabs of beef and swine carcass in slaughterhouses in Ukraine and characterize their genes, which are responsible for pathogenic properties. A total of 230 samples of swabs from beef (130) and swine (100) carcasses were obtained from 5 slaughterhouses in Ukraine between 2012 and 2015. Samples of swabs from carcasses were randomly selected at the final point of the process after the final washing of the carcass from the following areas: distal hind limb, abdomen (lateral and medial) from swine carcasses, brisket, flank and flank groin areas from beef carcasses. All samples were examined by culture-dependent method, after that each positive isolate of STEC was analyzed by multiplex PCR to detect the stx1, stx2, and eae genes. Out of 230 collected samples, seven (7.2%) were contaminated with STEC. The highest prevalence of STEC was found in swabs from beef carcasses (8.1%) in comparison to swabs from swine carcasses (5.7%). The stx1 gene was the predominant gene detected in all STEC positive samples. The eae gene was found in one of the examined isolates from beef carcass. Three isolates from swabs of beef carcass carried both stx1 and stx2 genes, one isolate showed association between stx1 and eae genes, one isolate was positive for stx1 gene only. In swabs from swine carcasses (2 isolates) stx1 and stx2 genes were presented simultaneously. The results of this study suggested that fresh raw meat could be a potential vehicle for transmission of the Shiga toxin-producing strain of E. coli to humans. This is the first report of STEC prevalence in beef and swine carcasses in Ukraine and these data will be valuable for microbiological risk assessment and help the appropriate services to develop strategies to mitigate health risk.

scholarly journals Reply to Comment on “The Occurrence of Shiga Toxin-Producing E. coli in Aquaponic and Hydroponic Systems”

Horticulturae ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 37
Author(s):  
Yi-Ju Wang ◽  
Amanda J. Deering ◽  
Hye-Ji Kim
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Cross Contamination ◽  
E Coli ◽  
Hydroponic Systems

Recently, the Aquaponic Association (AA) published a statement through multiple outlets in response to our article entitled “The Occurrence of Shiga Toxin-Producing E. coli in Aquaponic and Hydroponic Systems.” In this paper, we reported that Shiga toxin-producing Escherichia coli (STEC) was found in fish feces, in the water of both aquaponic and hydroponic systems, and on the surface of the roots of lettuce, basil, and tomato regardless of the system, but not in the edible portions of the plants. Our results demonstrated that the presence of STEC in aquaponics was due to the introduction of contaminated fish that were brought into the system and that cross-contamination might have occurred in the adjacent hydroponic systems during handling events. [...]

scholarly journals The Occurrence of Shiga Toxin-Producing E. coli in Aquaponic and Hydroponic Systems

Horticulturae ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 1 ◽  
Author(s):  
Yi-Ju Wang ◽  
Amanda J. Deering ◽  
Hye-Ji Kim
Keyword(s):  
Food Safety ◽  
Foodborne Pathogens ◽  
Shiga Toxin ◽  
Production Systems ◽  
Salmonella Spp ◽  
Safety Hazards ◽  
E Coli ◽  
Hydroponic Systems ◽  
Microbiological Analyses ◽  
Potential Food

Food safety concerns have been raised over vegetables and herbs grown in aquaponics and hydroponics due to the reuse of wastewater and spent nutrient solutions. This study was conducted to determine the occurrence of foodborne pathogens in greenhouse-based aquaponic and hydroponic systems. Fish feces, recirculating water, roots, and the edible portions of lettuce, basil, and tomato were collected at harvest, and microbiological analyses were conducted for the bacterial pathogens Shiga toxin-producing Escherichia coli (STEC), Listeria monocytogenes, and Salmonella spp. Enrichments and selective media were used for the isolation, and presumptive positive colonies were confirmed by PCR. STEC was found in fish feces, in the water of both systems, and on the surface of the roots of lettuce, basil, and tomato regardless of the system. However, contaminated water did not lead to the internalization of STEC into the roots, leaves, and/or fruit of the plants. Meanwhile, L. monocytogenes and Salmonella spp. were not present in any samples examined. Our results demonstrated that there are potential food safety hazards for fresh produce grown in aquaponic and hydroponic production systems.

Testing of Swine Feces Obtained through the National Animal Health Monitoring System's Swine 2000 Study for the Presence of Escherichia coli O157:H7†

2007 ◽  
Vol 70 (6) ◽  
pp. 1489-1492 ◽  
Author(s):  
INGRID FEDER ◽  
JEFFREY T. GRAY ◽  
RACHEL A. PEARCE ◽  
PINA M. FRATAMICO ◽  
ERIC BUSH ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Health Monitoring ◽  
Shiga Toxin ◽  
Animal Health ◽  
Escherichia Coli O157 ◽  
Fecal Samples ◽  
Hemolysin Gene ◽  
Shiga Toxin 2 ◽  
Swine Feces ◽  
Stx1 Gene

Fecal samples collected from healthy pigs from 13 of the top 17 swine-producing states were tested for Escherichia coli O157:H7 as part of the National Animal Health Monitoring System Swine 2000 study. Serogroup O157 strains were isolated from 106 of 2,526 fecal samples. None of the isolates were positive by PCR for the fliC h7 (H7 flagellin) gene or for the hly933 (hemolysin) gene; however, one isolate was positive for the stx1 gene (Shiga toxin 1), an additional four isolates were positive for the stx2 gene (Shiga toxin 2), and three isolates possessed the eae gene (intimin).

scholarly journals Risk Factors for Positivity to Shiga Toxin-Producing Escherichia coli and Salmonella enterica in Backyard Production Systems Animals from Metropolitana Region, Chile: A Threat to Public Health?

2021 ◽  
Vol 18 (20) ◽  
pp. 10730
Author(s):  
Erika Pavez-Muñoz ◽  
Bastián Fernández-Sanhueza ◽  
Constanza Urzúa-Encina ◽  
Nicolás Galarce ◽  
Raúl Alegría-Morán
Keyword(s):  
Public Health ◽  
Risk Factors ◽  
Escherichia Coli ◽  
Shiga Toxin ◽  
Salmonella Enterica ◽  
Production Systems ◽  
Epidemiological Surveillance ◽  
Small Scale ◽  
Simpson Index ◽  
Potential Threat

In the Metropolitana region of Chile there are 3836 backyard production systems (BPS), characterized as small-scale systems. They act as a source of zoonotic pathogens, such as Salmonella enterica and Shiga toxin-producing Escherichia coli (STEC), whose prevalence in BPS has not been fully described. The objective of this study was to determine the positivity for both agents in BPS and to establish the risk factors related to their presence. In each BPS, an epidemiological survey was undertaken, and stool samples were collected to detect these pathogens via bacteriological culture and conventional PCR techniques. Subsequently, multivariable logistic regression models were applied to establish the risk factors associated with their presence. BPS positivity rates of 11.76% for STEC and 4.7% for S. enterica were observed. The systems showed poor welfare standards and a lack of biosecurity measures. The risk factor analysis concluded that the Gini–Simpson index (p = 0.030; OR = 1.717) and the presence of neighboring intensive poultry or swine production systems (p = 0.019; OR = 20.645) act as factors that increased the risk of positivity with respect to STEC. In the case of S. enterica, exchanging embryonated eggs (p = 0.021; OR = 39) and the presence of debeaked chickens (p = 0.001; OR = 156) were determined as factors that increased the risk of positivity for this agent. For positivity with respect to both pathogens, the Gini–Simpson index (p = 0.030; OR = 1.544) and being INDAP/PRODESAL users (p = 0.023; OR = 15.026) were determined as factors that increased the risk, whereas the type of confinement (p = 0.002; OR = 0.019) decreased it. Epidemiological surveillance of these neglected populations is lacking, highlighting the fact that STEC and S. enterica maintenance on BPS represents a potential threat to public health.

scholarly journals Antimicrobial Usage Factors and Resistance Profiles of Shiga Toxin-Producing Escherichia coli in Backyard Production Systems From Central Chile

2021 ◽  
Vol 7 ◽  
Author(s):  
Erika Pavez-Muñoz ◽  
Camilo González ◽  
Bastián Fernández-Sanhueza ◽  
Fernando Sánchez ◽  
Beatriz Escobar ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Shiga Toxin ◽  
Animal Species ◽  
Production Systems ◽  
Close Contact ◽  
Principal Component ◽  
Antimicrobial Usage ◽  
Size Number ◽  
Multivariable Regression

Shiga toxin-producing Escherichia coli (STEC) is a zoonotic pathogen and important cause of foodborne disease worldwide. Many animal species in backyard production systems (BPS) harbor STEC, systems characterized by low biosecurity and technification. No information is reported on STEC circulation, antimicrobial resistance (AMR) and potential drivers of antimicrobial usage in Chilean BPS, increasing the risk of maintenance and transmission of zoonotic pathogens and AMR generation. Thus, the aim of this study was to characterize phenotypic and genotypic AMR and to study the epidemiology of STEC isolated in BPS from Metropolitana region, Chile. A total of 85 BPS were sampled. Minimal inhibitory concentration and whole genome sequencing was assessed in 10 STEC strain isolated from BPS. All strains were cephalexin-resistant (100%, n = 10), and five strains were resistant to chloramphenicol (50%). The most frequent serotype was O113:H21 (40%), followed by O76:H19 (40%), O91:H14 (10%), and O130:H11 (10%). The stx1 type was detected in all isolated strains, while stx2 was only detected in two strains. The Stx subtype most frequently detected was stx1c (80%), followed by stx1a (20%), stx2b (10%), and stx2d (10%). All strains harbored chromosomal blaAmpC. Principal component analysis shows that BPS size, number of cattle, pet and horse, and elevation act as driver of antimicrobial usage. Logistic multivariable regression shows that recognition of diseases in animals (p = 0.038; OR = 9.382; 95% CI: 1.138–77.345), neighboring poultry and/or swine BPS (p = 0.006; OR = 10.564; 95% CI: 1.996–55.894), visit of Veterinary Officials (p = 0.010; OR = 76.178; 95% CI: 2.860–2029.315) and close contact between animal species in the BPS (p = 0.021; OR = 9.030; 95% CI: 1.385–58.888) increase significantly the risk of antimicrobial use in BPS. This is the first evidence of STEC strains circulating in BPS in Chile, exhibiting phenotypic AMR, representing a threat for animal and public health. Additionally, we identified factors acting as drivers for antimicrobial usage in BPS, highlighting the importance of integration of these populations into surveillance and education programs to tackle the potential development of antimicrobial resistance and therefore the risk for ecosystemic health.

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