scholarly journals Evaluation of the Effectiveness of the Activated Sludge Process in the Elimination Both ATB-Resistant and ATB-Susceptible E. coli Strains

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5868
Author(s):  
Iwona Beata Paśmionka ◽  
Karol Bulski ◽  
Piotr Herbut ◽  
Elżbieta Boligłowa ◽  
Frederico Márcio C. Vieira ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Activated Sludge ◽  
Fecal Coliform ◽  
Antimicrobial Agents ◽  
Treated Wastewater ◽  
Coliform Bacteria ◽  
Diffusion Method ◽  
Activated Sludge Process ◽  
E Coli ◽  
Fecal Coliform Bacteria

Water reuse is now becoming a global necessity. However, one of the drawbacks in releasing wastewater into the environment is some persistent pollutants that are not completely removed in wastewater treatment plant. Residual bacteria and antibiotics in the inflowing wastewater can contribute to the antibiotic resistance spread in the aquatic environment. This study determined the effectiveness of activated sludge process for fecal coliform bacteria elimination, and also the Escherichia coli resistance to antimicrobial agents as erythromycin, azithromycin, clarithromycin, ofloxacin, ciprofloxacin, trimethoprim, and metronidazole in treated wastewater. The research was carried out using the membrane filtration technique, and the susceptibility of isolates to antimicrobial agents was tested by the disc diffusion method. The concentrations of fecal coliform bacteria and Escherichia coli differed significantly depending on the seasonal period in which it was carried out. Despite up to 99% reduction in the number of sanitary indicators in biologically treated wastewater, 89% of E. coli isolates resistant to the tested antibiotics was found, while 100% of the isolates were susceptible to metronidazole. Most of the isolates showed resistance to trimethoprim, and the fewest isolates were resistant to ofloxacin, indicating that some strains may react differently to antibiotics.

scholarly journals Fate and seasonal change of Escherichia coli resistant to different antibiotic classes at each stage of conventional activated sludge process

2020 ◽  
Vol 18 (6) ◽  
pp. 879-889 ◽  
Author(s):  
Ryo Honda ◽  
Chihiro Tachi ◽  
Mana Noguchi ◽  
Ryoko Yamamoto-Ikemoto ◽  
Toru Watanabe
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Activated Sludge ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Secondary Treatment ◽  
Activated Sludge Process ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Influent Wastewater

Abstract This study investigated the impact of each treatment stage of the activated sludge process on the fate of antibiotic resistant bacteria (ARB) in wastewater treatment plants (WWTPs). Wastewater and sludge samples were collected monthly at each stage of a commercial-scale WWTP. After 20–25 strains of indicator Escherichia coli were isolated from each sample on Chromocult Coliform Agar, antibiotic resistance of the isolates to amoxicillin (AMX), ciprofloxacin (CIP), norfloxacin (NFX), kanamycin (KM), sulfamethoxazole/trimethoprim (ST) and tetracycline (TC) were tested with the Kirby–Bauer disk diffusion method. As a result, activated sludge in the aeration tank and return sludge had higher abundance of antibiotic resistant E. coli than influent wastewater and secondary treatment effluent. AMX resistant E. coli was enriched in return sludge at the secondary clarifier. Higher temperature was also likely to cause an increase of AMX resistant E. coli in sludge. The antibiotic resistance profile of E. coli in secondary treatment effluent was more dependent on activated sludge than influent wastewater. These results suggested that activated sludge in WWTP possibly serves as a reservoir of ARB, and that behavior of ARB in WWTP differs by antibiotic classes.

scholarly journals Fethiye Bölgesinde Açıkta Satılan Tüketime Hazır Bazı Gıdalarda Koliform Bakteri Sayısının Belirlenmesi

2022 ◽  
Vol 9 (sp) ◽  
pp. 2552-2559
Author(s):  
Mehtap Çiftçi ◽  
Nilgün Öncül
Keyword(s):  
Escherichia Coli ◽  
Fecal Coliform ◽  
Food Industry ◽  
Ice Cream ◽  
Raw Milk ◽  
Coliform Bacteria ◽  
E Coli ◽  
Fecal Coliform Bacteria ◽  
Hygienic Measures ◽  
Intestinal Pathogens

Since coliform bacteria are common both in the intestine and in nature (soil, plant, etc.), they are considered as a sanitation indicator in the food industry. It is known that the majority of bacteria defined as fecal coliform in the coliform group are Escherichia coli. The presence of E. coli or fecal coliform bacteria in any sample is an indication that the necessary hygienic measures are not taken during production, storage, and sale. That means the sample is directly or indirectly contaminated with faeces, and/or other intestinal pathogens may also exist. In this study, raw milk, freshly squeezed fruit juices, unpackaged ice cream, shaved ice, and ice-cold samples were purchased from the famous touristic destination Fethiye and analyzed for coliform bacteria. For this purpose, the samples were purchased from local marketplaces, buffets, cafes, patisseries, restaurants, and roadsides at Fethiye. In total 60 samples were analyzed using Violet Red Bile (VRB) Agar. The results of coliform bacteria ranged

scholarly journals Occurrence of toxigenic Escherichia coli in raw milk cheese in Brazil

2007 ◽  
Vol 59 (2) ◽  
pp. 508-512 ◽  
Author(s):  
B.R. Paneto ◽  
R.P. Schocken-Iturrino ◽  
C. Macedo ◽  
E. Santo ◽  
J.M. Marin
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Antimicrobial Agents ◽  
Raw Milk ◽  
Diffusion Method ◽  
Chain Reaction ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Polymerase Chain ◽  
Raw Milk Cheese

The occurrence of toxigenic Escherichia coli in raw milk cheese was surveyed in Middle Western Brazil. Fifty samples of cheese from different supermarkets were analyzed for E.coli. The isolates were serotyped and screened for the presence of verotoxigenic E. coli (VTEC) and enterotoxigenic E. coli (ETEC) by Polymerase Chain Reaction (PCR). The susceptibility to thirteen antimicrobial agents was evaluated by the disk diffusion method. E.coli were recovered from 48 (96.0%) of the samples. The serogroups identified were O125 (6.0%), O111 (4.0%), O55 (2.0%) and O119 (2.0%). Three (6.0%) and 1(2.0%) of the E.coli isolates were VTEC and ETEC, respectively. Most frequent resistance was observed to the following antimicrobials: cephalothin (60.0%), nalidixic acid (40.0%), doxycyclin (33.0%), tetracycline (31.0%) and ampicillin (29.0%).

scholarly journals Molecular characterisation of antimicrobial resistance and virulence genes in Escherichia coli strains isolated from diarrhoeic and healthy rabbits in Tunisia

2020 ◽  
Vol 28 (2) ◽  
pp. 81
Author(s):  
Raouia Ben Rhouma ◽  
Ahlem Jouini ◽  
Amira Klibi ◽  
Safa Hamrouni ◽  
Aziza Boubaker ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Virulence Genes ◽  
Antimicrobial Agents ◽  
Antibiotic Resistance Genes ◽  
Virulence Gene ◽  
Diffusion Method ◽  
Class 1 Integron ◽  
E Coli ◽  
Class 1

The purpose of this study was to identify <em>Escherichia coli</em> isolates in diarrhoeic and healthy rabbits in Tunisia and characterise their virulence and antibiotic resistance genes. In the 2014-2015 period, 60 faecal samples from diarrhoeic and healthy rabbits were collected from different breeding farms in Tunisia. Susceptibility to 14 antimicrobial agents was tested by disc diffusion method and the mechanisms of gene resistance were evaluated using polymerase chain reaction and sequencing methods. Forty <em>E. coli</em> isolates were recovered in selective media. High frequency of resistance to tetracycline (95%) was detected, followed by different levels of resistance to sulphonamide (72.5%), streptomycin (62.5%), trimethoprim-sulfamethoxazole (60%), nalidixic acid (32.5%), ampicillin (37.5%) and ticarcillin (35%). <em>E. coli</em> strains were susceptible to cefotaxime, ceftazidime and imipenem. Different variants of bla<sub>TEM</sub>, <em>tet</em>, <em>sul</em> genes were detected in most of the strains resistant to ampicillin, tetracycline and sulphonamide, respectively. The presence of class 1 integron was studied in 29 sulphonamide-resistant <em>E. coli</em> strains from which 15 harboured class 1 integron with four different arrangements of gene cassettes, <em>dfrA17</em>+<em>aadA5</em> (n=9), <em>dfrA1</em> + <em>aadA1</em> (n=4), <em>dfrA12</em> + <em>addA2</em> (n=1), <em>dfrA12</em>+<em>orf</em>+<em>addA2</em> (n=1). The <em>qnrB</em> gene was detected in six strains out of 13 quinolone-resistant <em>E. coli</em> strains. Seventeen <em>E. coli</em> isolates from diarrhoeic rabbits harboured the enteropathogenic eae genes associated with different virulence genes tested (<em>fimA</em>, <em>cnf1</em>, <em>aer</em>), and affiliated to B2 (n=8) and D (n=9) phylogroups. Isolated <em>E. coli</em> strains from healthy rabbit were harbouring <em>fim A</em> and/or <em>cnf1</em> genes and affiliated to A and B1 phylogroups. This study showed that <em>E. coli</em> strains from the intestinal tract of rabbits are resistant to the widely prescribed antibiotics in medicine. Therefore, they constitute a reservoir of antimicrobial-resistant genes, which may play a significant role in the spread of antimicrobial resistance. In addition, the eae virulence gene seemed to be implicated in diarrhoea in breeder rabbits in Tunisia.

scholarly journals Detection of virulence genes and antimicrobial resistance profiles of Escherichia coli isolates from raw milk and artisanal cheese in Southern Brazil

2019 ◽  
Vol 40 (1) ◽  
pp. 163 ◽  
Author(s):  
Leandro Parussolo ◽  
Ricardo Antônio Pilegi Sfaciotte ◽  
Karine Andrezza Dalmina ◽  
Fernanda Danielle Melo ◽  
Ubirajara Maciel Costa ◽  
...  
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Antimicrobial Susceptibility ◽  
Virulence Genes ◽  
Antimicrobial Agents ◽  
Raw Milk ◽  
Diffusion Method ◽  
Public Health Issue ◽  
Southern Brazil ◽  
E Coli

The serrano artisanal cheese is a typical product from South region of Brazil, which is produced by skilled cheesemakers using raw milk. The contamination of this food by Escherichia coli has a great impact on public health, since it could threat the consumers’ health. The study evaluated the presence of virulence genes, antimicrobial susceptibility profiles and bofilm-production ability of Escherichia coli isolates obtained from raw milk and artisanal cheese produced in Southern Brazil. A total of 117 isolates of E. coli were characterized by multiplex PCR to detect the following virulence genes: eae for enteropatogenic E. coli (EPEC), lt and st for enterotoxigenic E. coli (ETEC), stx for shiga toxin-producing E. coli (STEC), stx and eae for enterohemorrhagic E. coli (EHEC), ipaH for enteroinvasive E. coli (EIEC) and aggR for enteroaggregative E. coli (EAEC). In addition, antimicrobial susceptibility profile to 22 antimicrobial agents was also performed by disk diffusion method, and we searched for extended-spectrum beta-lactamases (ESBL) and/or carbapenemase- producing isolates. Isolates that were positive for ESBL and carbapenemase were further investigated for the presence of the genes: blaTEM, blaSHV, blaOXA, blaCTX-M, for ESBL and blaOXA-48 for carbapenemase. Further, isolates had their ability to form biofilms investigated by the red Congo agar method. Virulence genes of E. coli were identified in 21.37% of the tested isolates, which were classified as EPEC (the most prevalent pathotype) and ETEC or EAEC. Ten (8.55%) of the total studied E. coli isolates revealed a multidrug-resistant profile, since they were resistant to three or more antimicrobial classes; whereas four isolates (3.42%) were classified as ESBL-producers and showed the presence of blaTEM gene. None of the isolates exhibited carbapenemase activity nor did they carry carbapenemase genes. From the total of E. coli isolates, 79 (67.52%) were considered potential biofilm producers. These results address a serious public health issue, since artisanal cheeses pose a risk to consumers’ health, since may be sources of dissemination of diarrheogenic E. coli, that can cause from subclinical to severe and fatal infections in children and adults, and also emphasize the need to improve adaptations/adjustments in the manufacturing processes of these products.

scholarly journals Presence and Sources of Fecal Coliform Bacteria in Epilithic Periphyton Communities of Lake Superior

2007 ◽  
Vol 73 (12) ◽  
pp. 3771-3778 ◽  
Author(s):  
Winfried B. Ksoll ◽  
Satoshi Ishii ◽  
Michael J. Sadowsky ◽  
Randall E. Hicks
Keyword(s):  
Fecal Coliform ◽  
Lake Superior ◽  
Early Summer ◽  
Dna Fingerprint ◽  
Fecal Coliforms ◽  
Coliform Bacteria ◽  
Overlying Water ◽  
E Coli ◽  
Fecal Coliform Bacteria ◽  
Animal Hosts

ABSTRACT Epilithic periphyton communities were sampled at three sites on the Minnesota shoreline of Lake Superior from June 2004 to August 2005 to determine if fecal coliforms and Escherichia coli were present throughout the ice-free season. Fecal coliform densities increased up to 4 orders of magnitude in early summer, reached peaks of up to 1.4 � 105 CFU cm−2 by late July, and decreased during autumn. Horizontal, fluorophore-enhanced repetitive-PCR DNA fingerprint analyses indicated that the source for 2% to 44% of the E. coli bacteria isolated from these periphyton communities could be identified when compared with a library of E. coli fingerprints from animal hosts and sewage. Waterfowl were the major source (68 to 99%) of periphyton E. coli strains that could be identified. Several periphyton E. coli isolates were genotypically identical (≥92% similarity), repeatedly isolated over time, and unidentified when compared to the source library, suggesting that these strains were naturalized members of periphyton communities. If the unidentified E. coli strains from periphyton were added to the known source library, then 57% to 81% of E. coli strains from overlying waters could be identified, with waterfowl (15 to 67%), periphyton (6 to 28%), and sewage effluent (8 to 28%) being the major potential sources. Inoculated E. coli rapidly colonized natural periphyton in laboratory microcosms and persisted for several weeks, and some cells were released to the overlying water. Our results indicate that E. coli from periphyton released into waterways confounds the use of this bacterium as a reliable indicator of recent fecal pollution.

scholarly journals Antibiotic resistance and virulence genes of extraintestinal pathogenic Escherichia coli from tropical estuary, south India

2015 ◽  
Vol 9 (05) ◽  
pp. 496-504 ◽  
Author(s):  
Divya Sukumaran ◽  
Abdulla A Mohamed Hatha
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Virulence Factor ◽  
Virulence Genes ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Virulence Factor Genes

Introduction: Escherichia coli strains can cause a variety of intestinal and extraintestinal diseases. Extraintestinal pathogenic E. coli (ExPEC) strains have the ability to cause severe extraintestinal infections. Multidrug resistance among ExPEC could complicate human infections. Methodology: Escherichia coli strains were isolated during the period of January 2010 to December 2012 from five different stations set at Cochin estuary. Susceptibility testing was determined by the disk-diffusion method using nine different antimicrobial agents. A total of 155 strains of Escherichia coli were screened for the presence of virulence factor genes including papAH, papC, sfa/focDE, iutA,and kpsMT II associated with ExPEC. Results: Among the 155 E. coli isolates, 26 (16.77%), carried two or more virulence genes typical of ExPEC. Furthermore, 19.23% of the ExPEC isolates with multidrug resistance were identified to belong to phylogenetic groups B2 and D. Statistically significant association of iutA gene in ExPEC was found with papC (p < 0.001) and kpsMT II (p < 0.001) genes. ExPEC isolates were mainly resistant to ampicillin (23.07%), tetracycline (19.23%), co-trimoxazole (15.38%), and cefotaxime (15.38%). The adhesion genes papAH and sfa/focDE were positively associated with resistance to gentamicin, chloramphenicol, and cefotaxime (p < 0.05). Conclusions: Co-occurrence of virulence factor genes with antibiotic resistance among ExPEC poses considerable threat to those who use this aquatic system for a living and for recreation.

scholarly journals MOLECULAR DETECTION AND ANTIBIOGRAM OF SHIGA TOXIN PRODUCING ESCHERICHIA COLI (STEC) ISOLATED FROM DIARRHEIC CHILDREN

2017 ◽  
Vol 14 (2) ◽  
pp. 289-295
Author(s):  
M. M. Islam ◽  
S. Ahamed ◽  
M. Y. Arafat ◽  
I. Hasan ◽  
M. Rahman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Molecular Detection ◽  
Antimicrobial Agents ◽  
Antibiotic Sensitivity ◽  
Biochemical Properties ◽  
Diffusion Method ◽  
College Hospital ◽  
E Coli ◽  
Antimicrobial Susceptibility Pattern

This study was designed to determine the shiga toxin producing genes and to investigate antibiotic sensitivity or resistant patterns of the Escherichia coli isolated from diarrheic children at Mymensingh Medical College Hospital, Bangladesh. A total of 83 stool samples were collected and screened for the detection of E. coli on the basis of cultural, staining and biochemical properties followed by molecular detection by Polymerase Chain Reaction (PCR) using genus specific 16SrRNA primers. Antimicrobial susceptibility pattern of E. coli was determined by disc diffusion method against 9 antimicrobial agents. In this study, 27 (32.53%) out of 83 samples, were confirmed as E. coli. Overall prevalence of shiga toxin producing E. coli (STEC) among the examined children was 1.20% (n=1/83).  Further, 27 E. coli isolates were analyzed for the presence of Stx-1 and Stx-2 genes by duplex-PCR.  The STEC isolate was confirmed to be positive for the presence of the Stx-2 gene only. Highest susceptibility of the E. coli isolates was found against Gentamicin (92.59%), followed by Ciprofloxacin (48.14%) and Moxifloxacin (33.33%). More than 77.78% of the isolates were resistant to more than three antibiotics thus defined as multi-drug resistant (MDR). In conclusion, Gentamicin and Ciprofloxacin can be recommended as the effective drugs successful treatment of STEC infections in children.

scholarly journals Research of Associated Resistance to Antimicrobial Agents of Extended Spectrum Beta-Lactamases Escherichia Coli and Klebsiella pneumoniae Strains Isolated in Senegal

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Ngom B ◽  
◽  
Wade SF ◽  
Diop TA ◽  
Diagne R ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Drug Resistant ◽  
Beta Lactamases ◽  
E Coli ◽  
Sick People ◽  
Extended Spectrum ◽  
Extended Spectrum Beta Lactamases

Introduction: Some strains of Escherichia coli and Klebsiella pneumoniae produce Extended Spectrum Beta-Lactamases (ESBL) may be responsible for various infections such as urinary infections. These Sick people are treated in the very serious cases by association antibiotics to class to betalactamins, aminosids and quinolons. But proliferation of multi-drug resistant strains involves decreasing therapeutic success. That’s why epidemiological study must be done in all laboratories of bacteriology. Purpose: The aim of the study was to research the resistance phenotypes of our E. coli and K. pneumoniae ESBL strains compared to others families of antibiotics. Material and methods: Thirty two (32) Extended Spectrum betalactamases E. coli and K. pneumoniae strains isolated from either hospitalized patients or sick people who came for consultation were studied. Susceptibility to antimicrobial agents was determined using an antibiotic disk (Bio-Rad) diffusion method on Mueller-Hinton agar (Bio-Rad). The results were interpreted according to the Standards of the French Antibiogram Committee (CA-SFM). Results: The study showed that most of these strains were multi-drug resistant. They were resistant to many beta-lactamines antibiotics. E. coli strains were also resistant at 70,34% to aminosids, at 96,72% to quinolons, at 58,3% to cotrimoxazol, at 26,1% to chloramphénicol and at 21,4% to colistin ; about K. pneumoniae, they were resistant at 72,6% to aminosids, at 88,95% to quinolons, at 86,7% to cotrimoxazol, at 44,4% to chloramphénicol and at 25% to colistin. But all these strains were sensitive at 100% to l’imipenem.

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