scholarly journals Performance of three pilot-scale hybrid constructed wetlands for total coliforms and Escherichia coli removal from primary effluent – a 2-year study in a subtropical climate

2014 ◽  
Vol 13 (2) ◽  
pp. 446-458 ◽  
Author(s):  
Florentina Zurita ◽  
Alejandra Carreón-Álvarez
Keyword(s):  
Escherichia Coli ◽  
Constructed Wetlands ◽  
Pilot Scale ◽  
World Health ◽  
First Year ◽  
Subtropical Climate ◽  
Total Coliforms ◽  
E Coli ◽  
Stage System ◽  
Health Organization

Three pilot-scale two-stage hybrid constructed wetlands were evaluated in order to compare their efficiency for total coliforms (TCol) and Escherichia coli removal and to analyze their performances in two 1-year periods of experimentation. System I consisted of a horizontal flow (HF) constructed wetland (CW) followed by a stabilization pond. System II was also configured with a HF CW as a first stage which was then followed by a vertical flow (VF) CW as a second stage. System III was configured with a VF CW followed by a HF CW. In the first year of evaluation, the HF–VF system was the most effective for TCol removal (p < 0.05) and achieved a reduction of 2.2 log units. With regard to E. coli removal, the HF–VF and VF–HF systems were the most effective (p < 0.05) with average reductions of 3.2 and 3.8 log units, respectively. In the second year, the most effective were those with a VF component for both TCol and E. coli which underwent average reductions of 2.34–2.44 and 3.44–3.74 log units, respectively. The reduction achieved in E. coli densities, in both years, satisfy the World Health Organization guidelines that require a 3–4 log unit pathogen reduction in wastewater treatment systems.

Study of constructed wetlands effluent disinfected with ozone

2014 ◽  
Vol 70 (1) ◽  
pp. 108-113 ◽  
Author(s):  
N. D. Miranda ◽  
E. L. Oliveira ◽  
G. H. R. Silva
Keyword(s):  
Constructed Wetlands ◽  
World Health ◽  
Constant Flow ◽  
Total Coliforms ◽  
E Coli ◽  
Complete Inactivation ◽  
Batch System ◽  
Health Organization ◽  
Almost All ◽  
Concentration Levels

The purpose of this research was to study the disinfection of sanitary effluent from constructed wetlands, evaluating the oxidation of organic matter, the formation of formaldehyde, as well as the efficiency of total coliforms and Escherichia coli inactivation. A constant flow of ozone was applied to the batch system in 5 and 10 mg.O3 L−1 doses with contact times of 5 and 10 min. This study revealed that the average values of formaldehyde formation ranged between 259.00 and 379.00 μg L−1, which means that the values are within World Health Organization recommended values. The total coliforms and E. coli showed complete inactivation in almost all tests. The dose of ozone 5 mg.O3 L−1 and contact time of 5 min were sufficient for a significant reduction of the concentration levels of pathogens in constructed wetlands effluent with similar characteristics, thus allowing for its agricultural reuse.

scholarly journals Effects of Water Quality and Post-Harvest Handling on Microbiological Contamination of Lettuce at Urban and Peri-Urban Locations of Ouagadougou, Burkina Faso

Foods ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 206 ◽  
Author(s):  
Juliane Dao ◽  
Kathrin Stenchly ◽  
Oumar Traoré ◽  
Philip Amoah ◽  
Andreas Buerkert
Keyword(s):  
Water Quality ◽  
Irrigation Water ◽  
World Health ◽  
Vegetable Production ◽  
Salmonella Spp ◽  
Total Coliforms ◽  
E Coli ◽  
Post Harvest ◽  
Health Organization ◽  
Production Areas

Vegetable production in urban gardens of Ouagadougou contributes to food security, but water for irrigation is often of low quality. This is particularly acute if irrigation water is taken from wastewater polluted channels. This study aimed at (i) verifying to what degree irrigation water quality is correlated with contamination of lettuce with Escherichia coli, total coliforms, and Salmonella spp., and (ii) assessing effects of post-harvest handling on pathogen development during the trade chain. We tested pathogen removal efficiency on lettuce by applying post-harvest washing. Irrigation water of production areas in Ouagadougou (n = 10) showed a mean E. coli load of 2.1 × 105 CFU 100 mL−1. In 60% of the cases, irrigation water did not meet the standards of the World Health Organization (WHO) for safe irrigation water, and in 30% of the cases, irrigation water was contaminated with Salmonella spp. Loads of total coliforms on lettuce leaves ranged from 2.9 × 103 CFU g−1 to 1.3 × 106 CFU g−1, while E. coli averaged 1.1 × 102 CFU g−1. Results on post-harvest handling revealed that microbial loads increased along the trade chain. Overall, half of all lettuce samples (n = 60) were tested positively for Salmonella spp. The experiment showed that appropriate post-harvest handling could prevent the increase of total coliforms.

scholarly journals The implementation of the five keys to safer food in campus cafeterias and the effects on Escherichia coli contamination

2020 ◽  
Vol 9 (3) ◽  
Author(s):  
Dewi Susanna ◽  
Aria Kusuma ◽  
Tiara Mairani ◽  
Lassie Fitria
Keyword(s):  
Escherichia Coli ◽  
Cross Sectional Study ◽  
World Health ◽  
Food Handlers ◽  
Cross Sectional ◽  
E Coli ◽  
Two Factors ◽  
Health Organization ◽  
And Behavior ◽  
Attitudes And Behavior

The World Health Organization developed five keys to safer food’s guidelines. This study aimed to determine the relationships between food handlers’ knowledge, attitudes, and behavior to the guideline and Escherichia coli (E. coli) contamination of food served at campus cafeterias. This cross-sectional study was carried out by interviewing 98 food handlers selling food and by testing samples for E. coli. The dependent variable was E. coli contamination, while the independent variables were the knowledge, attitudes, and behavior of food handlers based on the guideline. Each independent variable had five sub-variables that corresponded to the guideline. The data were analyzed using chisquare and logistic regression tests. The results showed that food handlers’ knowledge of cooking food thoroughly was significantly related to E. coli contamination (P=0.54 [P<0.05]; OR=2.990;95%CI:1.093– 8.180). Furthermore, the food handlers’ attitudes toward cooking food thoroughly were related to E. coli contamination (P=0.58 [P<0.05]; OR=0.385;95%CI:0.157– 0.944). There were two factors related to E. coli contamination: the food handlers’ knowledge of and attitudes toward the third key of the five keys to food safety.

scholarly journals Aktivitas Triterpenoid Kulit Batang Waru Jawa (Hibiscus tiliaceus L.) Terhadap Bakteri Escherichia coli

2020 ◽  
Vol 7 (1) ◽  
pp. 41-50
Author(s):  
Lisa Savitri ◽  
Kharisul Ihsan
Keyword(s):  
Escherichia Coli ◽  
World Health Organization ◽  
World Health ◽  
Disc Diffusion ◽  
E Coli ◽  
Ft Ir ◽  
Health Organization

Penyakit infeksi merupakan salah satu masalah kesehatan yang serius, khususnya di negara berkembang. Adanya resistensi antimikroba menyebabkan bahaya penyakit infeksi semakin parah, sehingga menjadi perhatian terbesar bagi kesehatan manusia. World Health Organization (WHO) memperkirakan bahwa pada tahun 2050, septikemia yang disebabkan oleh bakteri resisten antimikroba dapat mengakibatkan 10 juta kematian selama satu tahun. Tujuan penelitian ini adalah untuk melakukan isolasi senyawa triterpenoid yang terkandung dalam tanaman waru jawa (Hibiscus tiliaceus L.) serta melakukan identifikasi terhadap senyawa triterpenoid, dan melakukan pengujian aktivitas antibakteri Escherichia coli. Isolasi triterpenoid dari tanaman waru jawa diawali dengan maserasi menggunakan n-heksana, identifikasi triterpenoid, dan melakukan pengujian untuk aktivitas antibakteri. Hasil penelitian menunjukkan maserasi 3,2 kg serbuk kering kulit batang waru jawa menghasilkan ekstrak kental n-heksana sebesar 13,06 g. Hasil uji fitokimia menggunakan pereaksi Liebermann-Burchard menunjukkan ekstrak kental n-heksana positif mengandung triterpenoid. Pemisahan ekstrak kental n-heksana dengan kromatografi kolom menghasilkan isolat positif mengandung triterpenoid sebanyak 6 fraksi. Hasil identifikasi menggunakan spektrofotometer UV-Vis menunjukkan adanya serapan maksimum untuk fraksi 1, 2, dan 3 pada panjang gelombang 216,50 nm, 217 nm, dan 228,50 nm. Berdasarkan spektrogram FT-IR menunjukkan adanya gugus C-C, C=O,-C-H, -CH3, -CH2, dan C-O. Hasil aktivitas antibakteri dengan metode disc diffusion dan pengenceran dalam tabung menunjukkan bahwa fraksi 1, 3, 5, dan crude n-heksana mampu menghambat pertumbuhan bakteri Eschericia coli. MIC terhadap E. coli fraksi 1 sebesar 0,2 mg/mL.

scholarly journals A comparison of different O-antigen serogroups of Escherichia coli in semen samples of fertile and infertile men

2021 ◽  
Author(s):  
Ali Nabi ◽  
Mohammad Bagher Khalili ◽  
Gilda Eslami ◽  
Mahmood Vakili ◽  
Fatemeh Anbari ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
World Health ◽  
Semen Parameters ◽  
E Coli ◽  
O Antigen ◽  
Infertile Men ◽  
Significant Difference ◽  
Genital Tract Infections ◽  
Health Organization ◽  
Tract Infections

Objective: Male genital tract infections have been associated with infertility, and Escherichia coli has drawn increasing attention as an important bacterium in this context. This investigation aimed to characterize and compare the distributions of O-antigen serogroups of E. coli in the semen samples of fertile and infertile men. Methods: In this case-control study, semen samples were collected from 618 fertile and 1,535 infertile men. The E. coli-positive samples were evaluated in terms of concentration, morphology, viability, and motility parameters according to the World Health Organization 2010 guidelines. Finally, different serogroups of E. coli were identified by multiplex polymerase chain reaction targeting the O-antigen variations of the bacterium.Results: The prevalence of E. coli among fertile men was significantly higher than among infertile men (p<0.001). The sperm morphology, viability, and motility in the E. coli-positive fertile group were significantly higher than in the E. coli-positive infertile group (p<0.001). E. coli O6 was the most prevalent serogroup found in both groups. However, there was no significant difference in the frequency of different serogroups of E. coil between the two groups (p=0.55). Conclusion: Despite the higher prevalence of E. coli among fertile men, E. coli had more detrimental effects on semen parameters in infertile men. There was no significant difference in E. coli serogroups between the fertile and infertile groups.

scholarly journals A Syringe-Based Biosensor to Rapidly Detect Low Levels of Escherichia Coli (ECOR13) in Drinking Water Using Engineered Bacteriophages

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1953 ◽  
Author(s):  
Troy C. Hinkley ◽  
Spencer Garing ◽  
Paras Jain ◽  
John Williford ◽  
Anne-Laure M. Le Ny ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Membrane Filtration ◽  
Genetically Engineered ◽  
World Health ◽  
Selective Enrichment ◽  
E Coli ◽  
Detection Assay ◽  
Colony Forming Units ◽  
Health Organization

A sanitized drinking water supply is an unconditional requirement for public health and the overall prosperity of humanity. Potential microbial and chemical contaminants of drinking water have been identified by a joint effort between the World Health Organization (WHO) and the United Nations Children’s Fund (UNICEF), who together establish guidelines that define, in part, that the presence of Escherichia coli (E. coli) in drinking water is an indication of inadequate sanitation and a significant health risk. As E. coli is a nearly ubiquitous resident of mammalian gastrointestinal tracts, no detectable counts in 100 mL of drinking water is the standard used worldwide as an indicator of sanitation. The currently accepted EPA method relies on filtration, followed by growth on selective media, and requires 24–48 h from sample to results. In response, we developed a rapid bacteriophage-based detection assay with detection limit capabilities comparable to traditional methods in less than a quarter of the time. We coupled membrane filtration with selective enrichment using genetically engineered bacteriophages to identify less than 20 colony forming units (CFU) E. coli in 100 mL drinking water within 5 h. The combination of membrane filtration with phage infection produced a novel assay that demonstrated a rapid, selective, and sensitive detection of an indicator organism in large volumes of drinking water as recommended by the leading world regulatory authorities.

scholarly journals Effect of membrane fusion protein AdeT1 on the antimicrobial resistance of Escherichia coli

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Victoria L. Barlow ◽  
Shu-Jung Lai ◽  
Chia-Yu Chen ◽  
Cheng-Han Tsai ◽  
Shih-Hsiung Wu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Resistance Mechanism ◽  
Multidrug Resistant ◽  
World Health ◽  
Primary Resistance ◽  
E Coli ◽  
Membrane Fusion Protein ◽  
Wide Range ◽  
Health Organization

AbstractAcinetobacter baumannii is a prevalent pathogen that can rapidly acquire resistance to antibiotics. Indeed, multidrug-resistant A. baumannii is a major cause of hospital-acquired infections and has been recognised by the World Health Organization as one of the most threatening bacteria to our society. Resistance-nodulation-division (RND) type multidrug efflux pumps have been demonstrated to convey antibiotic resistance to a wide range of pathogens and are the primary resistance mechanism employed by A. baumannii. A component of an RND pump in A. baumannii, AdeT1, was previously demonstrated to enhance the antimicrobial resistance of Escherichia coli. Here, we report the results of experiments which demonstrate that wild-type AdeT1 does not confer antimicrobial resistance in E. coli, highlighting the importance of verifying protein production when determining minimum inhibitory concentrations (MICs) especially by broth dilution. Nevertheless, using an agar-based MIC assay, we found that propionylation of Lys280 on AdeT1 renders E. coli cells more resistant to erythromycin.

scholarly journals Emergence of Enteroaggregative Escherichia coli within the ST131 Lineage as a Cause of Extraintestinal Infections

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Erik J. Boll ◽  
Søren Overballe-Petersen ◽  
Henrik Hasman ◽  
Louise Roer ◽  
Kim Ng ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gastrointestinal Tract ◽  
Bloodstream Infections ◽  
The United States ◽  
World Health ◽  
Virulence Plasmid ◽  
Content Type ◽  
E Coli ◽  
Health Organization ◽  
Tract Infections

ABSTRACT Escherichia coli sequence type 131 (ST131) is a major cause of urinary and bloodstream infections. Its association with extended-spectrum β-lactamases (ESBLs) significantly complicates treatment. Its best-described component is the rapidly expanding H30Rx clade, containing allele 30 of the type 1 fimbrial adhesin gene fimH. This lineage appears to have emerged in the United States and spread around the world in part due to the acquisition of the ESBL-encoding blaCTX-M-15 gene and resistance to fluoroquinolones. However, non-H30 ST131 sublineages with other acquired CTX-M-type resistance genes are also emerging. Based on whole-genome analyses, we describe here the presence of an (fimH) H27 E. coli ST131 sublineage that has recently caused an outbreak of community-acquired bacteremia and recurrent urinary tract infections (UTIs) in Denmark. This sublineage has acquired both a virulence plasmid (pAA) that defines the enteroaggregative E. coli (EAEC) diarrheagenic pathotype and multiple genes associated with extraintestinal E. coli (ExPEC); combined, these traits have made this particular ST131 sublineage successful at colonizing its human host and causing recurrent UTI. Moreover, using a historic World Health Organization (WHO) E. coli collection and publicly available genome sequences, we identified a global H27 EAEC ST131 sublineage that dates back as far as 1998. Most H27 EAEC ST131 isolates harbor pAA or pAA-like plasmids, and our analysis strongly implies a single ancestral acquisition among these isolates. These findings illustrate both the profound plasticity of this important pathogenic E. coli ST131 H27 sublineage and genetic acquisitions of EAEC-specific virulence traits that likely confer an enhanced ability to cause intestinal colonization. IMPORTANCE E. coli ST131 is an important extraintestinal pathogenic lineage. A signature characteristic of ST131 is its ability to asymptomatically colonize the gastrointestinal tract and then opportunistically cause extraintestinal infections, such as cystitis, pyelonephritis, and urosepsis. In this study, we identified an ST131 H27 sublineage that has acquired the enteroaggregative diarrheagenic phenotype, spread across multiple continents, and caused multiple outbreaks of community-acquired ESBL-associated bloodstream infections in Denmark. The strain’s ability to both cause diarrhea and innocuously colonize the human gastrointestinal tract may facilitate its dissemination and establishment in the community.

scholarly journals A comparison of different O-antigen serogroups of Escherichia coli in semen samples of fertile and infertile men

2021 ◽  
Author(s):  
Ali Nabi ◽  
Mohammad Bagher Khalili ◽  
Gilda Eslami ◽  
Mahmood Vakili ◽  
Fatemeh Anbari ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
World Health ◽  
Semen Parameters ◽  
E Coli ◽  
O Antigen ◽  
Infertile Men ◽  
Significant Difference ◽  
Genital Tract Infections ◽  
Health Organization ◽  
Tract Infections

Objective: Male genital tract infections have been associated with infertility, and Escherichia coli has drawn increasing attention as an important bacterium in this context. This investigation aimed to characterize and compare the distributions of O-antigen serogroups of E. coli in the semen samples of fertile and infertile men. Methods: In this case-control study, semen samples were collected from 618 fertile and 1,535 infertile men. The E. coli-positive samples were evaluated in terms of concentration, morphology, viability, and motility parameters according to the World Health Organization 2010 guidelines. Finally, different serogroups of E. coli were identified by multiplex polymerase chain reaction targeting the O-antigen variations of the bacterium.Results: The prevalence of E. coli among fertile men was significantly higher than among infertile men (p<0.0001). The sperm morphology, viability, and motility in the E. coli-positive fertile group were significantly higher than in the E. coli-positive infertile group (p<0.0001). E. coli O6 was the most prevalent serogroup found in both groups. However, there was no significant difference in the frequency of different serogroups of E. coil between the two groups (p=0.55). Conclusion: Despite the higher prevalence of E. coli among fertile men, E. coli had more detrimental effects on semen parameters in infertile men. There was no significant difference in E. coli serogroups between the fertile and infertile groups.

Bacteriophages reduce Escherichia coli O157:H7 levels in experimentally inoculated sheep

2009 ◽  
Vol 89 (2) ◽  
pp. 285-293 ◽  
Author(s):  
S J Bach ◽  
R P Johnson ◽  
K. Stanford ◽  
T A McAllister
Keyword(s):  
Escherichia Coli ◽  
Oral Administration ◽  
Coliform Bacteria ◽  
Escherichia Coli O157 ◽  
Fecal Shedding ◽  
Total Coliforms ◽  
E Coli ◽  
Oral Inoculation ◽  
Experimental Treatments ◽  
And Control

Bacteriophage biocontrol has potential as a means of mitigating the prevalence of Escherichia coli O157:H7 in ruminants. The efficacy of oral administration of bacteriophages for reducing fecal shedding of E. coli O157:H7 by sheep was evaluated using 20 Canadian Arcott rams (50.0 ± 3.0) housed in four rooms (n = 5) in a contained facility. The rams had ad libitum access to drinking water and a pelleted barley-based total mixed ration, delivered once daily. Experimental treatments consisted of administration of E. coli O157:H7 (O157), E. coli O157:H7+bacteriophages (O157+phage), bacteriophages (phage), and control (CON). Oral inoculation of the rams with 109 CFU of a mixture of four nalidixic acid-resistant strains of E. coli O157:H7 was performed on day 0. A mixture of 1010 PFU of bacteriophages P5, P8 and P11 was administered on days -2, -1, 0, 6 and 7. Fecal samples collected on 14 occasions over 21 d were analyzed for E. coli O157:H7, total E. coli, total coliforms and bacteriophages. Sheep in treatment O157+phage shed fewer (P < 0.05) E. coli O157:H7 than did sheep in treatment O157. Populations of total coliforms and total E. coli were similar (P < 0.05) among treatments, implying that bacteriophage lysis of non-target E. coli and coliform bacteria in the gastrointestinal tract did not occur. Bacteriophage numbers declined rapidly over 21 d, which likely reduced the chance of collision between bacteria and bacteriophage. Oral administration of bacteriophages reduced shedding of E. coli O157:H7 by sheep, but a delivery system that would protect bacteriophages during passage through the intestine may increase the effectiveness of this strategy as well as allow phage to be administered in the feed.Key words: Escherichia coli O157:H7, bacteriophage, sheep, environment, coliforms

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