scholarly journals Evaluation of subsurface irrigation on microorganism contamination of romaine lettuce

2020 ◽  
Vol 187 ◽  
pp. 04009
Author(s):  
Rocio G. Reyes Esteves ◽  
Charles P. Gerba ◽  
Donald C. Slack
Keyword(s):  
Drip Irrigation ◽  
Gastrointestinal Disease ◽  
Microbial Pathogens ◽  
Health Concern ◽  
Contaminated Water ◽  
Romaine Lettuce ◽  
Ms2 Bacteriophage ◽  
E Coli ◽  
Significant Public Health ◽  
Subsurface Drip

The use of contaminated water to irrigate crops by surface, sprinkler, or conventional drip irrigation represents a significant public health concern due to the presence of multiple microbial pathogens associated with gastrointestinal disease. In this study, Escherichia coli and MS2 bacteriophage were used as microbial surrogates to evaluate the contamination of romaine lettuce (Lactuca sativa L. var. longifolia) using bottom watering pots simulating a subsurface drip irrigation (SDI) system in a greenhouse. The primary goal was to determine whether the exposure of lettuce plants to E. coli and MS2 would result in detectable levels of these microorganisms associated with the edible portions of plants. Plants were grown in bottom watering pots and were irrigated the last twelve days before harvesting with contaminated water containing E. coli and MS2 phage at 109 CFU/ml and 1011 PFU/ml, respectively. Harvested plants were processed to determine if E. coli or MS2 was associated with the plant surfaces or within the plant tissues. None of the samples was positive for either E. coli or MS2 bacteriophage, suggesting that subsurface irrigation systems effectively reduce the risk of produce-contamination with bacterial and viral pathogens.

scholarly journals Characterization of a New and Efficient Polyvalent Phage Infecting E. coli O157:H7, Salmonella spp., and Shigella sonnei

2021 ◽  
Vol 9 (10) ◽  
pp. 2105
Author(s):  
Su-Hyeon Kim ◽  
Damilare Adeyemi ◽  
Mi-Kyung Park
Keyword(s):  
Burst Size ◽  
Genomic Analysis ◽  
Cesium Chloride ◽  
Shigella Sonnei ◽  
Health Concern ◽  
Lytic Phage ◽  
Salmonella Spp ◽  
E Coli ◽  
Significant Public Health ◽  
Ph Range

Ongoing outbreaks of foodborne diseases remain a significant public health concern. Lytic phages provide promising attributes as biocontrol agents. This study characterized KFS-EC3, a polyvalent and lytic phage, which was isolated from slaughterhouse sewage and purified by cesium chloride density centrifugation. Host range and efficiency of plating analyses revealed that KFS-EC3 is polyvalent and can efficiently infect E. coli O157:H7, Salmonella spp., and Shigella sonnei. KFS-EC3 had a latent time of 20 min and burst size of ~71 phages/infected cell. KFS-EC3 was stable and infectious following storage at a pH range of 3 to 11 and a temperature range of −70°C to 60°C. KFS-EC3 could inhibit E. coli O157:H7 growth by 2 logs up to 52 h even at the lowest MOI of 0.001. Genomic analysis of KFS-EC3 revealed that it consisted of 167,440 bp and 273 ORFs identified as functional genes, without any genes associated with antibiotic resistance, virulence, allergenicity, and lysogenicity. This phage was finally classified into the Tequatrovirus genus of the Myoviridae family. In conclusion, KFS-EC3 could simultaneously infect E. coli O157:H7, S. sonnei, and Salmonella spp. with the lowest MOI values over long periods, suggesting its suitability for simultaneous pathogen control in foods.

Transfer of Escherichia coli O157:H7 to Romaine Lettuce due to Contact Water from Melting Ice

2008 ◽  
Vol 71 (2) ◽  
pp. 252-256 ◽  
Author(s):  
JIN KYUNG KIM ◽  
MARK A. HARRISON
Keyword(s):  
Escherichia Coli ◽  
Tap Water ◽  
Sampling Site ◽  
Contaminated Water ◽  
Escherichia Coli O157 ◽  
Romaine Lettuce ◽  
E Coli ◽  
Ice Melt ◽  
Leaf Surfaces ◽  
Shipping Containers

Ice can be used to chill romaine lettuce and maintain relative humidity during transportation. Escherichia coli O157:H7 may contaminate water used for ice. The objective of this study was to determine the potential for E. coli O157:H7 contamination of romaine lettuce from either ice contaminated with the pathogen or by transfer from lettuce surfaces via melting ice. In experiment 1, lettuce was spot inoculated with E. coli O157:H7 and chilled with ice prepared from uncontaminated tap water. In experiment 2, water inoculated with this pathogen was frozen and used to ice lettuce. Three heads of lettuce were stacked in each container and stored at 4 or 20°C. After the ice melted, E. coli O157:H7 attachment to and recovery from the lettuce leaves were determined. For experiment 1, the population of E. coli O157:H7 attached to inoculated sites averaged 3.8 and 5.5 CFU/cm2 at 4 and 20°C, respectively. Most of the uninoculated sites became contaminated with the pathogen due to ice melt. For experiment 2, 3.5 to 3.8 log CFU E. coli O157:H7 per cm2 was attached to the top leaf on the first head. After rinsing with chlorinated water (200 μg/ml), E. coli O157:H7 remained on the surface of the top head (1.8 to 2.0 log CFU/cm2). There was no difference in numbers of E. coli O157:H7 recovered from each sampling site at 4 and 20°C. Results show that E. coli O157:H7 can be transferred onto other produce layers in shipping containers from melted ice made of contaminated water and from contaminated to uncontaminated leaf surfaces.

scholarly journals Escherichia coli Survival on Strawberries and Unpacked Romaine Lettuce Washed Using Contaminated Water

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1390
Author(s):  
Manreet Bhullar ◽  
Bridget Perry ◽  
Ana Monge ◽  
Lillian Nabwiire ◽  
Angela Shaw
Keyword(s):  
Public Health ◽  
Microbial Contamination ◽  
Wash Water ◽  
Contaminated Water ◽  
Initial Population ◽  
Agricultural Water ◽  
Romaine Lettuce ◽  
E Coli ◽  
The Past ◽  
Foodborne Outbreaks

A number of foodborne outbreaks have occurred in the past decade, with higher incidences associated with romaine lettuce and strawberries. Contaminated agricultural water has been reported as the source of microbial contamination in most of these outbreaks. Maintaining the adequate and sanitary quality (0 E. coli/100 mL) of agricultural water can be challenging during post-harvest operations such as washing. The study focused on the attachment of generic E. coli (Rifampicin resistant) onto romaine lettuce and strawberries, mimicking the produce wash step. The produce was washed with contaminated water, air-dried, and stored in display units for 7 days. The produce was sampled randomly each day and analyzed for the surviving E. coli count. The results indicated that E. coli can survive in both lettuce and strawberries over extended periods. A survival population of 2.3 log CFU/cm2 (day 8) was observed on lettuce with an initial population of 2.8 log CFU/cm2 (day 0). On strawberries, the population reduced from 3.0 (day 0) to 1.7 log CFU/cm2 (day 7), with an initial E. coli concentration of approx. 6 log CFU/mL in the wash water. Strawberry leaves had a higher attachment of E. coli than the fruit (p < 0.05). In conclusion, romaine lettuce and strawberries washed with contaminated water can cause an outbreak affecting consumers and public health.

scholarly journals Preponderance of blaKPC-Carrying Carbapenem-Resistant Enterobacterales Among Fecal Isolates From Community Food Handlers in Kuwait

2021 ◽  
Vol 12 ◽  
Author(s):  
Ola H. Moghnia ◽  
Vincent O. Rotimi ◽  
Noura A. Al-Sweih
Keyword(s):  
Health Concern ◽  
Food Handlers ◽  
Gene Characterization ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Significant Public Health Concern ◽  
The Family ◽  
Significant Public Health ◽  
Molecular Mode ◽  
Sequence Types

Carbapenem-resistant Enterobacterales (CRE) are pathogens that have been found in several countries, with a significant public health concern. Characterizing the mode of resistance and determining the prevailing clones are vital to the epidemiology of CRE in our community. This study was conducted to characterize the molecular mode of resistance and to determine the clonality of the CRE fecal isolates among community food handlers (FHs) vs. infected control patients (ICPs) in Kuwait. Fecal CRE isolates obtained from FHs and ICPs from September 2016 to September 2018 were analyzed for their resistance genes. Gene characterization was carried out by polymerase chain reaction (PCR) assays and sequencing. Clonality of isolates was established by multilocus sequence typing (MLST). Of the 681 and 95 isolates of the family Enterobacterales isolated from FHs and ICPs, 425 (62.4%) and 16 (16.8%) were Escherichia coli, and 18 (2.6%) and 69 (72.6%) were Klebsiella pneumoniae, respectively. A total of 36 isolates were CRE with a prevalence of 5.3% among FH isolates and 87 (91.6%) among the ICPs. Of these, carbapenemase genes were detected in 22 (61.1%) and 65 (74.7%) isolates, respectively (p &lt; 0.05). The detected specific genes among FHs and ICPs were positive for blaKPC 19 (86.4%) and 35 (40.2%), and blaOXA 10 (45.5%) and 59 (67.8%), in addition to blaNDM 2 (9.1%) and 32 (36.8%), respectively. MLST assays of the E. coli and K. pneumoniae isolates revealed considerable genetic diversity and polyclonality as well as demonstrated multiple known ST types and eight novel sequence types. The study revealed a relatively high number of CRE harboring predominantly blaKPC-mediated CRE among the community FH isolates vs. predominant blaOXA genes among the ICPs. Those heterogeneous CRE isolates raise concerns and mandate more efforts toward molecular surveillance. A multinational study is recommended to monitor the spread of genes mediating CRE in the community of Arabian Peninsula countries.

scholarly journals Multidrug Resistant CTX-M-ProducingEscherichia coli: A Growing Threat among HIV Patients in India

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Kesavaram Padmavathy ◽  
Krishnan Padma ◽  
Sikhamani Rajasekaran
Keyword(s):  
Multidrug Resistance ◽  
Multidrug Resistant ◽  
Health Concern ◽  
Hiv Patients ◽  
E Coli ◽  
Significant Public Health Concern ◽  
Significant Public Health ◽  
Third Generation Cephalosporins ◽  
Highly Virulent ◽  
Esbl Producers

Extended Spectrumβ-Lactamases (ESBLs) confer resistance to third-generation cephalosporins and CTX-M types have emerged as the most prominent ESBLs worldwide. This study was designed to determine the prevalence of CTX-M positive ESBL-producing urinaryE. coliisolates from HIV patients and to establish the association of multidrug resistance, phylogeny, and virulence profile with CTX-M production. A total of 57 ESBL producers identified among 76E. colistrains isolated from HIV patients from South India were screened forblaCTX-M, AmpC production, multidrug resistance, and nine virulence associated genes (VAGs),fimH,pap,afa/dra,sfa/foc,iutA,fyuA,iroN,usp,andkpsMII.The majority (70.2%) of the ESBL producers harboredblaCTX-Mand were AmpC coproducers. Among the CTX-M producers, 47.5% were found to be UPEC, 10% harbored as many as 7 VAGs, and 45% possessedkpsMII. Multidrug resistance (CIPRSXTRGENR) was significantly more common among the CTX-M producers compared to the nonproducers (70% versus 41.2%). However, 71.4% of the multidrug resistant CTX-M producers exhibited susceptibility to nitrofurantoin thereby making it an effective alternative to cephalosporins/fluoroquinolones. The emergence of CTX-M-producing highly virulent, multidrug resistant uropathogenicE. coliis of significant public health concern in countries like India with a high burden of HIV/AIDS.

Transfer of Escherichia coli O157:H7 from Equipment Surfaces to Fresh-Cut Leafy Greens during Processing in a Model Pilot-Plant Production Line with Sanitizer-Free Water

2012 ◽  
Vol 75 (11) ◽  
pp. 1920-1929 ◽  
Author(s):  
ANNEMARIE L. BUCHHOLZ ◽  
GORDON R. DAVIDSON ◽  
BRADLEY P. MARKS ◽  
EWEN C. D. TODD ◽  
ELLIOT T. RYSER
Keyword(s):  
Escherichia Coli ◽  
Membrane Filtration ◽  
Tap Water ◽  
Plant Production ◽  
Health Concern ◽  
Escherichia Coli O157 ◽  
Romaine Lettuce ◽  
E Coli ◽  
Leafy Greens ◽  
Fresh Cut

Escherichia coli O157:H7 contamination of fresh-cut leafy greens has become a public health concern as a result of several large outbreaks. The goal of this study was to generate baseline data for E. coli O157:H7 transfer from product-inoculated equipment surfaces to uninoculated lettuce during pilot-scale processing without a sanitizer. Uninoculated cored heads of iceberg and romaine lettuce (22.7 kg) were processed using a commercial shredder, step conveyor, 3.3-m flume tank with sanitizer-free tap water, shaker table, and centrifugal dryer, followed by 22.7 kg of product that had been dip inoculated to contain ~106, 104, or 102 CFU/g of a four-strain avirulent, green fluorescent protein–labeled, ampicillin-resistant E. coli O157:H7 cocktail. After draining the flume tank and refilling the holding tank with tap water, 90.8 kg of uninoculated product was similarly processed and collected in ~5-kg aliquots. After processing, 42 equipment surface samples and 46 iceberg or 36 romaine lettuce samples (25 g each) from the collection baskets were quantitatively examined for E. coli O157:H7 by direct plating or membrane filtration using tryptic soy agar containing 0.6% yeast extract and 100 ppm of ampicillin. Initially, the greatest E. coli O157:H7 transfer was seen from inoculated lettuce to the shredder and conveyor belt, with all equipment surface populations decreasing 90 to 99% after processing 90.8 kg of uncontaminated product. After processing lettuce containing 106 or 104 E. coli O157:H7 CFU/g followed by uninoculated lettuce, E. coli O157:H7 was quantifiable throughout the entire 90.8 kg of product. At an inoculation level of 102 CFU/g, E. coli O157:H7 was consistently detected in the first 21.2 kg of previously uninoculated lettuce at 2 to 3 log CFU/100 g and transferred to 78 kg of product. These baseline E. coli O157:H7 transfer results will help determine the degree of sanitizer efficacy required to better ensure the safety of fresh-cut leafy greens.

DISINFECTION OF E. coli CONTAMINATED WATER USING TUNGSTEN TRIOXIDE-BASED PHOTOELECTROCATALYSIS

2016 ◽  
Vol 15 (4) ◽  
pp. 899-903 ◽  
Author(s):  
Donald E. Macphee ◽  
Efetobor Scott-Emuakpor ◽  
Graeme I. Paton ◽  
Malcolm J. Todd
Keyword(s):  
Tungsten Trioxide ◽  
Contaminated Water ◽  
E Coli

Subsurface Drip Irrigation and Fertigation of Broccoli

2002 ◽  
Vol 66 (1) ◽  
pp. 178 ◽  
Author(s):  
Thomas L. Thompson ◽  
Thomas A. Doerge ◽  
Ronald E. Godin
Keyword(s):  
Drip Irrigation ◽  
Subsurface Drip Irrigation ◽  
Subsurface Drip

Behaviour of the fecal pollution indicators in a soil irrigated with treated wastewater under onsurface and subsurface drip irrigation

2000 ◽  
Vol 42 (1-2) ◽  
pp. 75-79 ◽  
Author(s):  
C. Campos ◽  
G. Oron ◽  
M. Salgot ◽  
L. Gillerman
Keyword(s):  
Organic Matter ◽  
Drip Irrigation ◽  
Organic Matter Content ◽  
Fecal Pollution ◽  
Fecal Coliforms ◽  
Subsurface Drip Irrigation ◽  
Treated Wastewater ◽  
Reclaimed Wastewater ◽  
Pollution Indicators ◽  
Subsurface Drip

A critical objective for any wastewater reuse programme is to minimise health and environmental hazard. When applying wastewater to soil–plant systems, it is to be noted that the passage of water through the soil considerably reduces the number of microorganisms carried by the reclaimed wastewater. Factors that affect survival include number and type of microorganisms, soil organic matter content, temperature, moisture, pH, rainfall, sunlight, protection provided by foliage and antagonism by soil microflora. The purpose of this work was to examine the behaviour of fecal pollution indicators in a soil irrigated with treated wastewater under onsurface and subsurface drip irrigation. The experiment was conducted in a vineyard located at a commercial farm near the City of Arad (Israel). Wastewater and soil samples were monitored during the irrigation period and examined for fecal coliforms, somatic and F+ coliphages and helminth eggs. Physico-chemical parameters were controlled in order to determine their relationship with removal of microorganisms. The results showed high reduction of the concentration of microorganisms when wastewater moves through the soil; and a good correlation between the reduction of fecal pollution indicators and moisture content, organic matter concentration and pH. The application of secondary treated domestic wastewater in this specific soil and under these irrigation systems affect the survival of microorganisms, thus reducing the health and environmental risk.

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