scholarly journals Resistance of Escherichia coli and Enterococcus spp. to selected antimicrobial agents present in municipal wastewater

2013 ◽  
Vol 11 (4) ◽  
pp. 600-612 ◽  
Author(s):  
Aneta Luczkiewicz ◽  
Ewa Felis ◽  
Aleksandra Ziembinska ◽  
Anna Gnida ◽  
Ewa Kotlarska ◽  
...  

In this study, the susceptibility to erythromycin (E) and to trimethoprim/sulfamethoxazole (SXT) among isolates of Enterococcus spp. and Escherichia coli was tested, respectively. Both fecal indicators were detected and isolated from raw (RW) and treated wastewater (TW) as well as from samples of activated sludge (AS) collected in a local wastewater treatment plant (WWTP). Biodiversity of bacterial community in AS was also monitored using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Additionally, distribution of sul1–3 genes conferring sulfonamide resistance was tested among SXT-resistant E. coli. Simultaneously, basic physicochemical parameters and concentrations of eight antimicrobial compounds (belonging to folate pathway inhibitors and macrolides class) were analyzed in RW and TW samples. Six of the selected antimicrobial agents, namely: erythromycin, clarithromycin, trimethoprim, roxithromycin, sulfamethoxazole, and N-acetyl-sulfamethoxazole were detected in the wastewater samples. Bacterial biodiversity of AS samples were comparable with no relevant differences. Among tested Enterococcus spp., E-resistant isolates constituted 41%. SXT resistance was less prevalent in E. coli with 11% of isolates. The genes conferring resistance to sulfonamides (sul1–3) were detected in SXT-resistant E. coli of wastewater origin with similar frequencies as in other environmental compartments, including clinical ones.

2021 ◽  
Vol 12 ◽  
Author(s):  
Harvey N. Summerlin ◽  
Cícero C. Pola ◽  
Eric S. McLamore ◽  
Terry Gentry ◽  
Raghupathy Karthikeyan ◽  
...  

High demand for food and water encourages the exploration of new water reuse programs, including treated municipal wastewater usage. However, these sources could contain high contaminant levels posing risks to public health. The objective of this study was to grow and irrigate a leafy green (romaine lettuce) with treated wastewater from a municipal wastewater treatment plant to track Escherichia coli and antibiotic-resistant microorganisms through cultivation and post-harvest storage to assess their fate and prevalence. Contamination levels found in the foliage, leachate, and soil were directly (p < 0.05) related to E. coli concentrations in the irrigation water. Wastewater concentrations from 177 to 423 CFU ml−1 resulted in 15–25% retention in the foliage. Leachate and soil presented means of 231 and 116% retention, respectively. E. coli accumulation on the foliage was observed (p < 0.05) and increased by over 400% during 14-day storage (4°C). From randomly selected E. coli colonies, in all four biomass types, 81 and 34% showed resistance to ampicillin and cephalothin, respectively. Reclaimed wastewater usage for leafy greens cultivation could pose potential health risks, especially considering the bacteria found have a high probability of being antibiotic resistance. Successful reuse of wastewater in agriculture will depend on appropriate mitigation and management strategies to guarantee an inexpensive, efficient, and safe water supply.


2005 ◽  
Vol 3 (3) ◽  
pp. 297-304 ◽  
Author(s):  
Clarivel Lasalde ◽  
Roberto Rodriguez ◽  
Gary A. Toranzos ◽  
Henry H. Smith

Previous studies have shown that Escherichia coli can be isolated from non-polluted rivers and from bromeliad axilae in pristine areas of tropical rain forests. Finding E. coli in pristine environments is unusual because this bacterium is thought to only survive in the gut of warm-blooded animals and thus its presence should indicate recent fecal contamination. The aims of this study were 1) to determine if E. coli is part of the native soil microbiota in tropical rain forests and 2) to determine if genetic heterogeneity exists among E. coli populations. High concentrations of total coliforms (104–105 cells per 10 g of soil dry weight) and low concentrations of thermotolerant coliforms (101–102 cells per 10 g dry soil, the majority of these were found to be E. coli) were detected. PCR using uidA-specific primers was done on DNA purified from E. coli isolates and the resulting amplicons analysed by denaturing-gradient gel electrophoresis (DGGE). Out of several hundred isolates, mixtures of nine different amplicons were consistently observed. The different patterns of DGGE observed indicate that the E. coli populations in these pristine soils are genetically heterogeneous. Fecal and environmental E. coli isolates were also analysed by pulsed-field gel electrophoresis (PFGE) which showed high DNA sequence variation among the E. coli isolates. Because of these differences in the genomes, PFGE did not allow grouping of environmental versus human isolates of E. coli when compared side to side. The apparent genetic polymorphisms, as a result of genetic heterogeneity, observed in isolates from the same pristine site indicate that source tracking may be difficult to carry out using E. coli as the target organism.


2020 ◽  
Author(s):  
Chinyere B. Chigor ◽  
Ini-Abasi I. Ibangha ◽  
Nkechinyere O. Nweze ◽  
Chizoba A. Ozochi ◽  
Valentino C. Onuora ◽  
...  

AbstractIn spite of treated wastewater presenting itself as an attractive alternative to scarce quality water in the developing countries, the associated contamination of fresh produce by irrigation waters leading to outbreak of foodborne illnesses is on the rise. Horizontal transfer of integrons play important role in the spread and maintenance of antimicrobial resistance among strains of Escherichia coli. This study assessed the effluents from the University of Nigeria, Nsukka Wastewater Treatment Plant (UNN-WWTP) as well as vegetables irrigated with the effluent, and vegetables sold in selected markets from Nsukka and Enugu cities for the presence of E. coli and determined the prevalence integrons in multidrug-resistant isolates. Isolation of E. coli was done using eosin methylene blue agar and isolates subjected to Gram staining for identification of presumptive colonies. Confirmation of E. coli was achieved by polymerase chain reaction (PCR) technique, targeting beta-glucuronidase (uidA). Resistance to antibiotics was determined using the Bauer-Kirby disk diffusion assay and the Clinical and Laboratory Standard Institute criteria. Integrons were detected by multiplex PCR using primers specific for class 1 and 2 integrons. A total of 178 E. coli isolates were obtained from WWTP effluent (41), and vegetables from greenhouse (46), farms (55) and market (36). Multi-drug resistance was detected in all the isolates, ranging from five-drug resistance in a single isolate to 16-drug resistance patterns in two different isolates. Of the total isolates, class 1 integrons were abundantly detected in 175 (98.3%) and class 2 in 5 (2.8%). All the class 2 integrons were found in isolates that were positive for class 1. The high detection of E. coli in the studied effluent and vegetables pose potential public health hazards heightened by observed multidrug resistance in all the isolates and the high prevalence of class 1 integron. It is concluded that the vegetable samples are significant reservoirs for potentially pathogenic E. coli. Therefore, vegetable irrigation farming with unsafe water should be discontinued, while appropriate improvement strategies to ensure compliance should be facilitated without further delay.


2019 ◽  
Vol 100 ◽  
pp. 00061 ◽  
Author(s):  
Adriana Osińska ◽  
Ewa Korzeniewska ◽  
Monika Harnisz ◽  
Sebastian Niestępski ◽  
Piotr Jachimowicz

Wastewater treatment plants (WWTPs) are major reservoirs of antibiotic-resistant bacteria (ARB) which are transported to the natural environment with discharged effluents. Samples of untreated wastewater (UWW) and treated wastewater (TWW) from four municipal WWTPs and samples of river water collected upstream (URW) and downstream (DRW) from the effluent discharge point were analyzed in the study. The total counts of bacteria resistant to β-lactams and tetracyclines and the counts of antibiotic-resistant Escherichia coli were determined. Antibiotic-resistant bacteria, including antibiotic-resistant E. coli, were removed with up to 99.9% efficiency in the evaluated WWTPs. Despite the above, ARB counts in TWW samples were high at up to 1.25x105 CFU/mL in winter and 1.25x103 CFU/mL in summer. Antibiotic-resistant bacteria were also abundant (up to 103 CFU/ml) in URW and DRW samples collected in winter and summer. In both UWW and TWW samples, the counts of ARB and antibiotic-resistant E. coli were at least one order of magnitude lower in summer than in winter. The study revealed that despite the high efficiency of bacterial removal in the wastewater treatment processes, considerable amounts of ARB are released into the environment with TWW and that the percentage of ARB in total bacterial counts increases after wastewater treatment.


2016 ◽  
Vol 74 (11) ◽  
pp. 2727-2735 ◽  
Author(s):  
Yixuan Yang ◽  
Fei Tang ◽  
Xiaoling Su ◽  
Hua Yin ◽  
Fei Ge

To access better removal of nutrients with algae-based techniques, a dominant alga from real municipal wastewater was identified and its capacity in removing low concentrations of nitrogen (NH+4 or NO−3) and phosphorus (PO3−4) was evaluated. Results showed that Oedogonium brevicingulatum, a filamentous green alga, was confirmed as the dominant alga in the secondary effluent of a municipal wastewater treatment plant by polymerase chain reaction-denaturing gradient gel electrophoresis. Low concentrations of NH+4 or NO−3 (≤5 mg N L−1) and PO3−4 (≤0.5 mg P L−1) were 100% removed by the algae in a 7-d test. The maximum nutrient removal rate (Vmax) and the half-saturation constant (Km) for NH+4 (10.03 ± 0.95 mg g−1d−1 and 0.19 ± 0.03 mg L−1) and NO−3 (8.43 ± 0.21 mg g−1 d−1 and 0.27 ± 0.11 mg L−1) indicated the uptake capability for NH+4 is higher than that for NO−3. Meanwhile, it showed higher affinity for PO3−4 (Vmax: 1.42 ± 0.02 mg g−1 d−1; Km: 0.02 ± 0.00 mg L−1) with NH+4 as nitrogen source than that (Vmax: 1.24 ± 0.15 mg g−1 d−1; Km: 0.06 ± 0.03 mg L−1) with NO−3 as nitrogen source. Moreover, nutrient removal efficiencies were observed steady when nitrogen/phosphorus ratio ranged from 5:1 to 20:1. These results suggest that the dominant algae from municipal wastewater have potentials to be applied in nutrient removal.


2016 ◽  
Vol 82 (18) ◽  
pp. 5505-5518 ◽  
Author(s):  
Shuai Zhi ◽  
Graham Banting ◽  
Qiaozhi Li ◽  
Thomas A. Edge ◽  
Edward Topp ◽  
...  

ABSTRACTEscherichia colihas been proposed to have two habitats—the intestines of mammals/birds and the nonhost environment. Our goal was to assess whether certain strains ofE. colihave evolved toward adaptation and survival in wastewater. Raw sewage samples from different treatment plants were subjected to chlorine stress, and ∼59% of the survivingE. colistrains were found to contain a genetic insertion element (IS30) located within theuspC-flhDCintergenic region. The positional location of the IS30element was not observed across a library of 845E. coliisolates collected from various animal hosts or within GenBank or whole-genome reference databases for human and animalE. coliisolates (n= 1,177). Phylogenetics clustered the IS30element-containing wastewaterE. coliisolates into a distinct clade, and biomarker analysis revealed that these wastewater isolates contained a single nucleotide polymorphism (SNP) biomarker pattern that was specific for wastewater. These isolates belonged to phylogroup A, possessed generalized stress response (RpoS) activity, and carried the locus of heat resistance, features likely relevant to nonhost environmental survival. Isolates were screened for 28 virulence genes but carried only thefimHmarker. Our data suggest that wastewater contains a naturalized resident population ofE. coli. We developed an endpoint PCR targeting the IS30element within theuspC-flhDCintergenic region, and all raw sewage samples (n= 21) were positive for this marker. Conversely, the prevalence of this marker inE. coli-positive surface and groundwater samples was low (≤5%). This simple PCR assay may represent a convenient microbial source-tracking tool for identification of water samples affected by municipal wastewater.IMPORTANCEThe results of this study demonstrate that some strains ofE. coliappear to have evolved to become naturalized populations in the wastewater environment and possess a number of stress-related genetic elements likely important for survival in this nonhost environment. The presence of non-host-adapted strains in wastewater challenges our understanding of usingE. colias a microbial indicator of wastewater treatment performance, suggesting that theE. colistrains present in human and animal feces may be very different from those found in treated wastewater.


2007 ◽  
Vol 53 (10) ◽  
pp. 1174-1184 ◽  
Author(s):  
Thomas V. D’Elia ◽  
Chester R. Cooper ◽  
Carl G. Johnston

This research validates a novel approach for source tracking based on denaturing gradient gel electrophoresis (DGGE) analysis of DNA extracted from Escherichia coli isolates. Escherichia coli from different animal sources and from river samples upstream from, at, and downstream of a combined sewer overflow were subjected to DGGE to determine sequence variations within the 16S–23S intergenic spacer region (ISR) of the rrnB ribosomal operon. The ISR was analyzed to determine if E. coli isolates from various animal sources could be differentiated from each other. DNA isolated from the E. coli animal sources was PCR amplified to isolate the rrnB operon. To prevent amplification of all 7 E. coli ribosomal operons by PCR amplification using universal primers, sequence-specific primers were utilized for the rrnB operon. Another primer set was then used to prepare samples of the 16S–23S ISR for DGGE. Comparison of PCR–DGGE results between human and animal sources revealed differences in the distribution and frequency of the DGGE bands produced. Human and Canada Goose isolates had the most unique distribution patterns and the highest percent of unique isolates and were grouped separately from all other animal sources. Method validation suggests that there are enough host specificity and genetic differences for use in the field. Field results at and around a combined sewer overflow indicate that this method can be used for microbial source tracking.


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.


2015 ◽  
Vol 64 (2) ◽  
pp. 143-148 ◽  
Author(s):  
MAŁGORZATA KACPRZAK ◽  
KRZYSZTOF FIJAŁKOWSKI ◽  
ANNA GROBELAK ◽  
KAROLINA ROSIKOŃ ◽  
AGNIESZKA RORAT

Numerous studies have recently shown that molecular biology tools can allow for early diagnosis of pathogens and can substitute existing cost and time-taking traditional methods. One of them, the qPCR, is successfully used in microbiology and its utility has been assessed for many different biological materials. The aim of this study was to: 1) determine, optimize and apply qPCR as a method to detect Escherichia coli and Salmonella spp. in primary influents and final effluents from municipal wastewater treatment plant 2) define if addition of ethidium bromide monoazide (EMA) before DNA extraction can allow to distinguish between alive and dead bacteria, 3) quantify E. coli and Salmonella spp. in wastewater during four seasons by qPCR and traditional spread plate method and determine the correlation between the indicator and pathogenic microorganisms. The obtained results has shown that qPCR can be used as a quantitative method in the diagnosis of investigated bacteria in wastewater with EMA pretreatment as a crucial step for a proper quantitative analysis of the presence of these bacteria in wastewater. Both E. coli and Salmonella spp. bacteria species were present in all samples of primary influents and final effluents. Our study shown that the quantity of investigated bacteria is strictly correlated with the season that they were obtained in.


2019 ◽  
Vol 54 (3) ◽  
Author(s):  
Isaías De la Rosa-Gómez ◽  
María Teresa Olguín ◽  
David Alcántara

Water disinfection was performed using Mexican clinoptilolite-rich tuffs from Oaxaca and Sonora with different particle sizes exchanged with silver ions. Samples of Escherichia coli (ATCC 8739) suspended in distilled water (wastewater-like) and municipal wastewater containing coliforms (E. coli as a representative microorganisms from the coliform consortium), were treated in this investigation. E. coli is considered an indicator of microbiological contamination of water, so levels of this microorganism after zeolite treatment indicate how well the disinfection process worked. It was found that particle size, the amount of silver in the modified zeolitic rocks, the origin of the zeolitic material and the type of aqueous media containing E. coli all play important roles in the wastewater disinfection process.  


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