High prevalence of multidrug-resistant Escherichia coli and Enterococcus spp. in river water, upstream and downstream of a wastewater treatment plant

2014 ◽  
Vol 12 (3) ◽  
pp. 426-435 ◽  
Author(s):  
Lucinda J. Bessa ◽  
Ana Barbosa-Vasconcelos ◽  
Ângelo Mendes ◽  
Paulo Vaz-Pires ◽  
Paulo Martins da Costa

In this study, microbial quality and antimicrobial resistance of faecal bacteria from a Portuguese river were assessed. River water samples collected upstream and downstream of a wastewater treatment plant, throughout a 3-month period, were used for the enumeration of Escherichia coli and Enterococcus spp. The highest numbers found for E. coli and enterococci were 1.1 × 104 and 1.2 × 104 colony forming units (CFU)/100 ml, respectively. In total, 144 isolates of E. coli and 144 of enterococci were recovered and tested for antimicrobial susceptibility; 104 E. coli and 78 Enterococcus spp. showed resistance to one or more antimicrobial drugs. Overall, 70 and 32 different resistance patterns were found for E. coli and enterococci, respectively. One E. coli showed resistance to imipenem and 29 isolates were extended spectrum β-lactamase-producers. Multidrug-resistant E. coli belonged mostly to groups A, B1 and group D. Enterococcus spp. were mostly resistant to rifampicin, tetracycline, azithromycin and erythromycin; six isolates showed resistance to vancomycin, presenting the VanA phenotype. The high levels of E. coli and enterococci and the remarkable variety of antimicrobial resistance profiles, reinforces the theory that these river waters can be a pool of antimicrobial resistance determinants, which can be easily spread among different bacteria and reach other environments and hosts.

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Joshua Mbanga ◽  
Akebe Luther King Abia ◽  
Daniel Gyamfi Amoako ◽  
Sabiha. Y. Essack

Abstract Background Access to safe water for drinking and domestic activities remains a challenge in emerging economies like South Africa, forcing resource-limited communities to use microbiologically polluted river water for personal and household purposes, posing a public health risk. This study quantified bacterial contamination and the potential health hazards that wastewater treatment plant (WWTP) workers and communities may face after exposure to waterborne pathogenic bacteria in a WWTP and its associated surface water, respectively. Results Escherichia coli (Colilert®-18/ Quanti-Tray® 2000) and enterococci (Enterolert®/ Quanti-Tray® 2000) were quantified and definitively identified by real-time polymerase chain reaction targeting the uidA and tuf genes, respectively. An approximate beta-Poisson dose-response model was used to estimate the probability of infection (Pi) with pathogenic E. coli. Mean E. coli concentration ranged from 2.60E+ 02/100 mL to 4.84E+ 06/100 mL; enterococci ranged from 2.60E+ 02/100 mL to 3.19E+ 06/100 mL across all sampled sites. Of the 580 E. coli isolates obtained from this study, 89.1% were intestinal, and 7.6% were extraintestinal pathogenic E. coli. The 579 enterococci obtained were 50.4% E. faecalis (50.4%), 31.4% E. faecium, 3.5%, E. casseliflavus and 0.7% E. gallinarum. The community health risk stemming from the use of the water for recreational and domestic purposes revealed a greater health risk (Pi) from the ingestion of 1 mL of river water from upstream (range, 55.1–92.9%) than downstream (range, 26.8–65.3%) sites. The occupational risk of infection with pathogenic E. coli for workers resulting from a once-off unintentional consumption of 1 mL of water was 0% (effluent) and 23.8% (raw influent). Multiple weekly exposures of 1 mL over a year could result in a Pi of 1.2 and 100% for the effluent and influent, respectively. Conclusion Our findings reveal that there is a potentially high risk of infection for WWTP workers and communities that use river water upstream and downstream of the investigated WWTP.


2021 ◽  
Vol 9 (4) ◽  
pp. 698
Author(s):  
Mykhailo Savin ◽  
Gabriele Bierbaum ◽  
Judith Kreyenschmidt ◽  
Ricarda Schmithausen ◽  
Esther Sib ◽  
...  

Escherichia coli is frequently associated with multiple antimicrobial resistances and a major cause of bacterial extraintestinal infections in livestock and humans. However, data on the epidemiology of (i) multidrug-resistant (MDR) and (ii) extraintestinal pathogenic E. coli (ExPEC) in poultry and pig slaughterhouses in Germany is currently lacking. Selected E. coli isolates (n = 71) with phenotypic resistance to cephalosporins from two poultry and two pig slaughterhouses expressing high MDR rates (combined resistance to piperacillin, cefotaxime and/or ceftazidime, and ciprofloxacin) of 51.4% and 58.3%, respectively, were analyzed by whole-genome sequencing. They constituted a reservoir for 53 different antimicrobial resistance determinants and were assigned various sequence types, including high-risk clones involved in human infections worldwide. An ExPEC pathotype was detected in 17.1% and 5.6% of the isolates from poultry and pig slaughterhouses, respectively. Worryingly, they were recovered from scalding water and eviscerators, indicating an increased risk for cross-contaminations. Uropathogenic E. coli (UPEC) were detected in the effluent of an in-house wastewater treatment plant (WWTP) of a poultry slaughterhouse, facilitating their further dissemination into surface waters. Our study provides important information on the molecular characteristics of (i) MDR, as well as (ii) ExPEC and UPEC regarding their clonal structure, antimicrobial resistance and virulence factors. Based on their clinical importance and pathogenic potential, the risk of slaughterhouse employees’ exposure cannot be ruled out. Through cross-contamination, these MDR E. coli pathotypes may be introduced into the food chain. Moreover, inadequate wastewater treatment may contribute to the dissemination of UPEC into surface waters, as shown for other WWTPs.


Author(s):  
Maria Clara V. M. Starling ◽  
Elizângela P. Costa ◽  
Felipe A. Souza ◽  
Elayne C. Machado ◽  
Juliana Calábria de Araujo ◽  
...  

AbstractThis work investigated an innovative alternative to improve municipal wastewater treatment plant effluent (MWWTP effluent) quality aiming at the removal of contaminants of emerging concern (caffeine, carbendazim, and losartan potassium), and antibiotic-resistant bacteria (ARB), as well as disinfection (E. coli). Persulfate was used as an alternative oxidant in the solar photo-Fenton process (solar/Fe/S2O82−) due to its greater stability in the presence of matrix components. The efficiency of solar/Fe/S2O82− at neutral pH using intermittent iron additions is unprecedented in the literature. At first, solar/Fe/S2O82− was performed in a solar simulator (30 W m−2) leading to more than 60% removal of CECs, and the intermittent iron addition strategy was proved effective. Then, solar/Fe/S2O82− and solar/Fe/H2O2 were compared in semi-pilot scale in a raceway pond reactor (RPR) and a cost analysis was performed. Solar/Fe/S2O82− showed higher efficiencies of removal of target CECs (55%), E. coli (3 log units), and ARB (3 to 4 log units) within 1.9 kJ L−1 of accumulated irradiation compared to solar/Fe/H2O2 (CECs, 49%; E. coli, 2 log units; ARB, 1 to 3 log units in 2.5 kJ L−1). None of the treatments generated acute toxicity upon Allivibrio fischeri. Lower total cost was obtained using S2O82− (0.6 € m−3) compared to H2O2 (1.2 € m−3). Therefore, the iron intermittent addition aligned to the use of persulfate is suitable for MWWTP effluent quality improvement at neutral pH.


2012 ◽  
Vol 65 (4) ◽  
pp. 589-595 ◽  
Author(s):  
A. Ouali ◽  
H. Jupsin ◽  
J. L. Vasel ◽  
L. Marouani ◽  
A. Ghrabi

Korba wastewater treatment plant is a conventional activated sludge followed by three maturation ponds (MP1, MP2, MP3) in series acting as a tertiary treatment. The first study of wastewater treatment plants showed that the effluent concentration of Escherichia coli and enterococci at the outlet of the (MP3) varies between 103 and 104CFU/100 ml. After the hydrodynamic study conducted by Rhodamine WT which showed short-circuiting in the MP1, two baffles were introduced in the first maturation pond (MP1) to improve the hydrodynamic and the sanitary performances. The second hydraulic study showed that the dispersion number ‘d’ was reduced from 1.45 to 0.43 by this engineering intervention and the Peclet number was raised from 0.69 to 2.32. The hydraulic retention time was increased by 14 h. Because of well-designed baffles, the removal efficiency of E. coli and enterococci was raised between 0.2 and 0.7 log units for the first maturation pond.


Author(s):  
José Roberto Guimarães ◽  
Regiane Aparecida Guadagnini ◽  
Regina Maura Bueno Franco ◽  
Luciana Urbano dos Santos

AbstractThis study evaluated the effectiveness of H


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