Hydroponic cultivation of lettuce (Lactuca sativa) using effluents from primary, secondary and tertiary +UV treatments

2005 ◽  
Vol 5 (1) ◽  
pp. 95-100
Author(s):  
R. Keller ◽  
K. Perim ◽  
S. Semionato ◽  
E. Zandonade ◽  
S. Cassini ◽  
...  

The aim of this study was to evaluate the potential cultivation of lettuce (Lactuca sativa) with domestic wastewater effluents with different levels of treatment from a compact WWTP in Brazil. Vegetables were grown in five treatments: nutrient solution (control), secondary effluent diluted 50%, secondary effluent not diluted, tertiary effluent UV irradiated, and UASB effluent. Microbiological analyses from leaves showed low levels of contamination with E. coli, thermotolerant coliforms and total coliforms. Salmonella spp. and helminth eggs were not detected. However, roots showed hardly any concentration of these microorganisms. These results shows that it is possible to cultivate leafy vegetables in a hydroponic system with treated effluents, taking care at the moment of harvesting vegetables.

2004 ◽  
Vol 50 (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. Keller ◽  
R.F. Passamani-Franca ◽  
F. Passamani ◽  
L. Vaz ◽  
S.T. Cassini ◽  
...  

The aim of this study was to verify the efficiency of removal of microorganisms in effluents of a Wastewater Treatment Plant (WWTP) comprising an association of a UASB reactor followed by three submerged aerated biofilters (BAF) and one tertiary filter. The WWTP designed to treat domestic wastewater from a population of 1,000 inhabitants showed high removal efficiency for organic matter and suspended solids. Helminth eggs were also efficiently removed from the tertiary effluent and were found in the sludge from the UASB reactor; however, removal of bacteria in this system was very low. To enhance the efficiency of the system, the effluent from tertiary filters was submitted to UV disinfection in a real scale reactor. Our results showed that UV irradiation was very effective at lowering the concentrations of E. coli, thermotolerant coliforms and coliphages to acceptable levels for agricultural reuse. Salmonella spp. and helminth eggs were seeded into the tertiary effluent before passing through the UV reactor. Salmonella was not found in the final effluent, but helminth eggs were not completely inactivated by UV irradiation and viable eggs were detected after 28 d of incubation.


2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Dayawatee Goburdhun ◽  
Mahima D. Beeharry ◽  
Keshnee Reega ◽  
Arvind Ruggoo ◽  
Hudaa Neetoo

This study was carried out to assess the microbiological status of three hot meals served in eight selected school canteens of Mauritius, with two schools randomly selected from each of the four school zones of the island. Three individual samples of farata, panini, or fried noodles were collected at each school during two independent visits. The three individual samples of each food type collected during each visit were then pooled before being subjected to microbiological analyses. A total of 48 composite samples were analyzed. The parameters tested were Total Viable Count (TVC), Escherichia coli, Salmonella spp., Clostridium perfringens, Staphylococcus aureus, and Listeria spp. The microbiological analyses revealed that paninis were deemed as generally acceptable with TVC falling in the range of 3.0-5.7 Log CFU/g and undetectable levels of S. aureus and E. coli. In contrast, fried noodles and faratas harboured a moderately high level of TVC (4.4-6.7 Log CFU/g) and objectionably high levels S. aureus (3.1 to 5.0 Log CFU/g) and E. coli (3.1-5.1 Log CFU/g) for seven out of the eight schools.


2018 ◽  
Vol 48 (4) ◽  
Author(s):  
Maxsueli Aparecida Moura Machado ◽  
Barbara Müller ◽  
Ricardo César Tavares Carvalho ◽  
Eduardo Eustáquio de Souza Figueiredo

ABSTRACT: Brazil is the largest exporter of beef of the world and Mato Grosso State is the highest beef producer in this country. To maintain product competitiveness and market expansion, sanitary hygienic control of the entire process is indispensable to ensure the attainment of harmless beef and quality. The objective of this study was to evaluate the hygienic sanitary conditions of vacuum-packed beef produced by establishments qualified for export in the state of Mato Grosso, Brazil. A total of 60 samples were submitted to coliforms counts at 35°C and at 45°C and E. coli. The mean contamination by at 35°C and coliforms at 45°C were 3,1 x 102MPN/g and 7.7MPN/g respectively. The presence of E. coli was verified in five samples, representing an occurrence of 8.3% (5/60), and Salmonella spp. in 5% (03/60) of the analyzed samples. The MPN (Most Probable Number) average of coliforms at 35°C and 45°C are in accordance to national and international legislation; however, the presence of Samonella spp., E. coli in some sample indicates a low risk of occurrence of salmonellosis and colibacillosis transmitted by the evaluated beef. However, transmission risk of these diseases cannot be ruled out, since the presence of E. coli does not depend on the amount of coliforms and national legal standards established for the group of thermotolerant coliforms.


1996 ◽  
Vol 59 (7) ◽  
pp. 778-780 ◽  
Author(s):  
KELLY J. KARR ◽  
ELIZABETH A. E. BOYLE ◽  
CURTIS L. KASTNER ◽  
JAMES L. MARSDEN ◽  
RANDALL K. PHEBUS ◽  
...  

Standardized microbiological sampling and testing procedures were developed that can be used throughout the beef slaughter and processing industry to facilitate the collection and any desired compilation of comparative data. Twenty samples each from carcasses (brisket, flank, and rump areas combined); subprimal cuts (clods); lean trim; and cutting and/or conveyor surfaces were collected in three slaughter and processing operations, with the first operation being a preliminary trial and resulting in no reported data. Microbiological analyses for Clostridium perfringens, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, Campylobacter jejuni/coli, total coliforms, E. coli Biotype I, and aerobic mesophilic bacteria (aerobic plate count, APC) were performed on all samples by an outside laboratory. The procedures developed were effective in allowing samples to be collected, shipped, and analyzed in the same manner for all operations. From a logistical standpoint, approximately 20 samples each of carcasses, clods, lean trim, and surfaces could be taken within 4 to 6 h by five people. Forty samples each of carcass, clod, lean trim, and conveyor surfaces from two plants tested negative for E. coli O157:H7, Salmonella spp., and Listeria spp., with the exception of L. monocytogenes being isolated from one carcass and one clod sample. APCs and total coliform counts were between 103 to 105 and 102 to 103 CFU/cm2 or CFU/g, respectively, for the 40 samples each of carcasses, clods, and lean trim. APCs for surface swab counts ranged from ≤ 10 to 103 CFU/cm2.


2020 ◽  
Vol 9 (8) ◽  
pp. e334985750
Author(s):  
Marília Rodrigues Serra ◽  
Gustavo Oliveira Everton ◽  
Amanda Mara Teles ◽  
Adenilde Nascimento Mouchrek

This article aims to evaluate the hygienic and sanitary quality of 60 samples of vegetables (Lactuca sativa and Nasturtium officinale) of conventional and hydroponic cultivation commercialized in São Luís (MA) and to evaluate the efficiency of conventional sanitizers. Microbiological analyses were performed based on the methodology described in the Compendium of Methods for the Microbiological Examination of Foods - APHA. Of the 60 samples analyzed, 95.00% (n=57) were in disagreement with the current legislation for coliforms at 45°C, and the presence of Escherichia coli was identified in both vegetables. All sanitizers presented inhibitory potential. Therefore, the satisfactory results obtained in this study ensure the use of sanitizers, emphasizing their viable cost, efficient and fast application.


Agriculture ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 14
Author(s):  
Jennifer Ekman ◽  
Adam Goldwater ◽  
Mark Bradbury ◽  
Jim Matthews ◽  
Gordon Rogers

Incorporation of manures into soil can add nutrients, improve soil structure and enhance biodiversity, thereby improving the sustainability of vegetable production systems. Unfortunately, manures can also potentially contain human enteric pathogens. To reduce the risk of contamination, Australian guidelines recommend a withholding period of 90 days between manure application and harvest for high-risk products such as leafy salad greens. Our study examined the appropriateness of these guidelines under conditions replicating those on a commercial vegetable farm. Cow manure and poultry litter with/without addition of non-pathogenic strains of Escherichia coli (E. coli), Listeriainnocua and Salmonella sv. sofia were added to sandy and clay loam soils typical of those used to grow vegetables. Bacterial populations were monitored in the soil and on crops of cos lettuce during spring (A), summer (B) and autumn (C) trials, with testing conducted by a commercial laboratory. Significant declines in E. coli occurred within 6 to 16 days in all trials. Modelling indicated that E. coli populations would be at or close to the limit of detection within 50 days for all of the combinations tested. A 2–3 log die-off of Salmonella spp. occurred within three weeks. However, occasional detections continued throughout trial A. As a result, the probability of detection after 50 days fell from 1.0 to 0.1 and 0.02 in trials B and C, respectively, but remained at 0.44 in trial A. Listeria spp. was the most persistent in soil but was not detected on lettuce at commercial maturity. While this study was limited in scope, the results suggest that a 90 day withholding period between application of manure and harvest significantly reduces risk from enteric pathogens under Australian field conditions.


Horticulturae ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 1 ◽  
Author(s):  
Yi-Ju Wang ◽  
Amanda J. Deering ◽  
Hye-Ji Kim

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.


2018 ◽  
Vol 69 (5) ◽  
pp. 1240-1243
Author(s):  
Manuela Arbune ◽  
Mioara Decusara ◽  
Luana Andreea Macovei ◽  
Aurelia Romila ◽  
Alina Viorica Iancu ◽  
...  

The aim of the present study was to characterize the antibiotic resistance profile of enterobacteriaceae strains isolated in Infectious Diseases Hospital Galati, Romania, during 2016, in order to guide the local antibiotic stewardship strategy. There are 597 biological samples with positive cultures for enterobacteriaceae, related to invasive and non-invasive infections. The main bacterial genus were E. coli 62%, Klebsiella spp 15%, Proteus spp 11% and Salmonella spp 6%. Over a half of isolated strains have one or more antibiotic resistance. The resistance level depends on bacterial genus, with highest level found among the rare isolates: Enterobacter spp, Citrobacter spp, Morganella spp and Serratia spp. The rate of MDR was 17.,6% for E. coli, 40.9% for Klebsiella spp and 50.7% for Proteus spp. while the rate of strains producing Extended Spectrum of Beta Lactamase are 7.2% for E. coli, 28.4% for Klebsiella spp and 12.3% for Proteus spp. The carbapenem resistant strains were found in 1.1% cases.


1995 ◽  
Vol 31 (5-6) ◽  
pp. 19-26 ◽  
Author(s):  
G. J. Medema ◽  
I. A. van Asperen ◽  
J. M. Klokman-Houweling ◽  
A. Nooitgedagt ◽  
M. J. W. van de Laar ◽  
...  

This pilot study was carried out to determine the relationship between microbiological water quality parameters and the occurrence of health complaints among triathletes. Data were collected at an Olympic distance triathlon (n=314) and a run-bike-run (n=81; controls for exposure to fresh water). At the time of the triathlon, the concentrations of Escherichia coli , thermotolerant coliforms, faecal streptococci, entero- and reoviruses, F-specific RNA phages, Salmonella, Campylobacter, Aeromonas, Plesiomonas shigelloides, Pseudomonas aeruginosa and Staphylococcus aureus were examined over the swimming course. Information on the occurrence of health complaints during the competition and in the week thereafter was collected through a written questionnaire. The results show that triathletes and run-bike-runners are comparable with respect to factors other than water exposure (age, sex, training history, physical stress, lower intestinal health complaints during the competition) that may influence the occurrence of health complaints in the week after the competition. Triathletes and run-bike-runners reported gastro-intestinal (7.7% vs 2.5%), respiratory (5.5% vs 3.7%), skin/mucosal (2.6% vs 1.2%), general (3.5% vs 1.2%) and total symptoms (14.8% vs 7.4%) in the week after the event. The health risks for triathletes for all symptom groups are not significantly higher than for run-bike-runners. The geometric mean concentration of faecal indicator bacteria is relatively low: E. coli 170/100 ml; faecal streptococci 13/100 ml, enteroviruses were present at concentrations of 0.1/l. The group of triathletes was homogeneusly and relatively intensely exposed to water; they all swam in the same body of water at the same time and 75% reported to have swallowed freshwater. It was concluded that this study design is suitable to study the relationship between health complaints and microbiological water quality. In the summers of 1993 and 1994, a study will be carried out concerning several run-bike-runs and triathlons in freshwaters of different quality.


1997 ◽  
Vol 35 (11-12) ◽  
pp. 157-163 ◽  
Author(s):  
G. J. Medema ◽  
I. A. van Asperen ◽  
A. H. Havelaar

As part of a prospective cohort study among triathletes to determine a relationship between the microbiological quality of fresh bathing water and the risk of acquiring an intestinal infection, the exposure of the triathletes to microbiological contaminants was assessed. Waters were collected at seven triathlons (swimming course 1–1.5km) held in the summer of 1993 and 1994 to have a range of water qualities. All were influenced by sewage effluents, most also by agricultural run-off. Samples were collected several weeks before the event to establish a sampling programme (1993) and during the actual exposure of the triathletes (1993 and 1994) and examined for thermotolerant coliforms alone (samples preceding the event) and for E. coli, faecal enterococci, Staphylococcus aureus, F-specific RNAphages, enteroviruses (1993 and 1994) and for thermophilic Campylobacter, Salmonella, Aeromonas, Plesiomonas shigelloides and Pseudomonas aeruginosa (1993). The samples taken in the weeks before the exposure showed significant differences in thermotolerant coliform concentration between locations, depths and times. Also during swimmer exposure, significant differences occurred in microorganism levels at the different sampling points over the swimming course. As the triathletes swam as a group, they were exposed to approximately the same water at the same time. The geometric mean concentration was used to characterise each site. In the epidemiological study, the risk of an intestinal infection correlated with the concentration of thermotolerant coliforms and E. coli but not with the other parameters. The geometric mean concentration of thermotolerant coliforms at the triathlons ranged from 11–330/100mL and 54–1,200/100mL E. coli. Ranking of the seven sites by faecal pollution level, based on the geometric mean concentration of a faecal indicator, resulted in a different ranking for each indicator. At the fresh water sites studied, only the ratio between the geometric mean density of E. coli and thermotolerant coliforms was constant. The ratio between the other parameters related to faecal pollution (faecal enterococci, F-specific RNA phages, enteroviruses) varied considerably. Water quality standards relating to faecal pollution can only be based on parameters that show a significant correlation with risk of intestinal illness.


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