Impact of UV disinfection on the virulence and antibiotic resistance gene profile of Escherichia coli in municipal wastewater and its receiving waters
Bibliographic record
Abstract
Fecal water contaminations have been known to cause severe disease outbreaks throughout the world, thus proper wastewater treatment can help to avoid them. Escherichia coli (E. coli) is a well-known microorganism that flourishes in the gut of warm-blooded animals and can cause disease, such as diarrhoea, urinary tract infection, dysentery-like illness, haemorrhagic colitis and neonatal meningitis. Previous studies have shown that the virulence gene profile of E. coli can accurately predict its in vivo pathogenicity in animal models. E. coli in municipal wastewaters was therefore used in this study as a model pathogenic microorganism to examine the effects of activated sludge and UV disinfection on its virulence and its antibiotic resistance gene profile. DNA microarrays were used to conduct genotyping. The virulence and antibiotic resistance gene profile of E. coli in the receiving waters impacted by the treatment plant were also investigated.E. coli isolates (540 in total) were collected in May 2011 from 6 locations at the Skyway Wastewater Treatment Plant (Burlington, Ontario) and the Hamilton Harbour, which is the receiving water body for the treatment plant's effluent. Samples were also collected from an avian-contaminated area to investigate a possible relationship between the pollution in the harbour and the pollution by wild birds and municipal effluents. Results showed that although UV disinfection decreased the E. coli counts by more than 2 logs, the percentage of E. coli with a pathogenic genotype in the surviving population had increased by almost 10%. The activated sludge system proliferated virulence and antibiotic resistance genes. 22.5% of all isolates were uropathogenic E. coli 6.7% incomplete extraintestinal pathogenic E. coli and 1.7% shiga-toxin associated E. coli. No strong correlation was found between the genotypes found in the treatment plant's effluent and the harbour samples. 40% of the treatment plant's isolates carried some antibiotic resistance genes with a higher proportion of isolates carrying multiple antibiotic resistance genes. The majority of the isolates (70%) did not carry any antibiotic resistance (AMR) genes. Most of the AMR genes detected corresponded to beta-lactams (20%), aminoglycosides (19.6%), tetracyclines (19.1%), phenicols (12.6%) and trimethoprim (11.5%). Also, results demonstrated that UV decreased (by 9%) the percentage of isolates that had multiple antibiotic resistance genes, while activated sludge increased this percentage (by 5%). No statistically significant difference was found in the distribution of the antibiotic resistance genes in the harbour samples or between the pathotypes and the presence of antibiotic resistance genes in any samples.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".