Tailoring Cytotoxicity of Antimicrobial Peptidomimetics with High Activity against Multidrug-Resistant Escherichia coli

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Jahnsen, Rasmus D; Sandberg-Schaal, Anne; Vissing, Karina Juul

2014-01-01

Infections with multidrug-resistant pathogens are an increasing concern for public health. Recently, subtypes of peptide-peptoid hybrids were demonstrated to display potent activity against multidrug-resistant Gram-negative bacteria. Here, structural variation of these antibacterial peptidomimetics...... cells. Thus, lead compounds with a high selectivity toward killing of clinically important multidrug-resistant E. coli were identified....

Isolation, Identification And Screening Antibacterial Activity from Marine Sponge-Associated Fungi Against Multidrug-Resistant (MDR) Escherichia coli

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Triandala Sibero, Mada; Sabdaningsih, Aninditia; Cristianawati, Olvi; Nuryadi, Handung; Karna Radjasa, Ocky; Sabdono, Agus; Trianto, Agus

2017-02-01

Irrational used of antibiotic in several decades ago causing resistant in bacteria and decreasing the cure rate of infectious diseases. Multidrug-resistant (MDR) Escherichia coli is known to cause various of infectious diseases such as urinary tract infection, nosocomial bloodstream infection, meningitis, bacteraemia, and gastrointestinal disease. Marine sponge-associated fungi have potential as source of new compound to combat MDR E. coli. The aims of this research were to isolate marine sponge-assosiated fungi, to screen potential fungi against MDR E. coli, to identify the potential fungi and its host sponge. There were 29 marine sponge-associated fungi successfully isolated from 9 sponges. Among 29 sponge-associated fungi screened, there were 7 isolates showed antibacterial activity against MDR E. coli. The best inhibition zone produced by MPS 14.1/MT 02 and MPS 14.3/MT 04 from sponge PP.SP.16.14. According to fungi identification result fungus MPS 14.1/MT 02 was identified as Trichoderma asperellum while MPS 14.3/MT 04 was identified as Trichoderma reesei. Sponge identification leaded the PP.SP.16.14 as Cinachyrella sp.

Phenotypic Characterization of Multidrug-resistant Escherichia Coli with Special Reference to Extended-spectrum-beta-lactamases and Metallo-beta-lactamases in a Tertiary Care Center.

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Shrestha, B; Shrestha, S; Mishra, S K; Kattel, H P; Tada, T; Ohara, H; Kirikae, T; Rijal, B P; Sherchand, J B; Pokhrel, B M

2015-01-01

The increasing reports on extended-spectrum-beta-lactamase and metallo-beta-lactamase producing Escherichia coli have addressed a potential threat to global health since it is found to be highly resistance to most of the currently available antibiotics including carbapenems. The present study was aimed to determine the antibiogram of extended-spectrum-beta-lactamase and metallo-beta-lactamase producing MDR E. coli isolates from various clinical samples. This was a cross-sectional study conducted over a period of seven months from December 2013 to July 2014 at bacteriology laboratory of Tribhuvan University Teaching Hospital. A total of 250 clinical specimens (urine, pus, sputum, blood, body fluid, bile, tissue and central venous pressure line tip) were processed from inpatients, with multidrug-resistant Escherichia coli infections. Standard microbiological techniques were used for isolation and identification of the isolates. The presence of extended-spectrum-beta-lactamase was detected by phenotypic confirmatory test recommended by Clinical and Laboratory Standards Institute and imipenem (IMP) /EDTA combined disc method was performed to detect metallo-beta-lactamase mediated resistance mechanism. We found high level of beta lactamase mediated resistance mechanism as part of multidrug resistance. Among 250 MDR isolates, 60% isolates were extended-spectrum-beta-lactamase producers and 17.2% isolates were metallo-beta-lactamase producers. Co-existence of extended-spectrum-beta-lactamase and metallo-beta-lactamase identified in 6.8% isolates. Beta-lactamase mediated resistance mechanisms are accounting very high in the multidrug resistant isolates of E. coli. Therefore, early detection of beta lactamase mediated resistant strains and their current antibiotic susceptibility pattern is necessary to avoid treatment failure and prevent the spread of MDR.

Photoinactivation of mcr-1 positive Escherichia coli

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Caires, C. S. A.; Leal, C. R. B.; Rodrigues, A. C. S.; Lima, A. R.; Silva, C. M.; Ramos, C. A. N.; Chang, M. R.; Arruda, E. J.; Oliveira, S. L.; Nascimento, V. A.; Caires, A. R. L.

2018-01-01

The emergence of plasmid-mediated colistin resistance in Enterobacteriaceae, mostly in Escherichia coli due to the mcr-1 gene, has revealed the need to develop alternative approaches in treating mcr-1 positive bacterial infections. This is because colistin is a broad-spectrum antibiotic and one of the ‘last-resort’ antibiotics for multidrug resistant bacteria. The present study evaluated for the first time, to the best of our knowledge, the efficacy of photoinactivation processes to kill a known mcr-1 positive E. coli strain. Eosin methylene-blue (EMB) was investigated as a photoantimicrobial agent for inhibiting the growth of a mcr-1 positive E. coli strain obtained from a patient with a diabetic foot infection. The photoantimicrobial activity of EMB was also tested in a non-multidrug resistant E. coli strain. The photoinactivation process was tested using light doses in the 30-45 J cm-2 range provided by a LED device emitting at 625 nm. Our findings demonstrate that a mcr-1 positive E. coli strain is susceptible to photoinactivation. The results show that the EMB was successfully photoactivated, regardless of the bacterial multidrug resistance; inactivating the bacterial growth by oxidizing the cells in accordance with the generation of the oxygen reactive species. Our results suggest that bacterial photoinactivation is an alternative and effective approach to kill mcr-1 positive bacteria.

Detection of multi-drug resistant Escherichia coli in the urban waterways of Milwaukee, WI

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Anthony D. Kappell

2015-04-01

Full Text Available Urban waterways represent a natural reservoir of antibiotic resistance which may provide a source of transferable genetic elements to human commensal bacteria and pathogens. The objective of this study was to evaluate antibiotic resistance of Escherichia coli isolated from the urban waterways of Milwaukee, WI compared to those from Milwaukee sewage and a clinical setting in Milwaukee. Antibiotics covering 10 different families were utilized to determine the phenotypic antibiotic resistance for all 259 E. coli isolates. All obtained isolates were determined to be multi-drug resistant. The E. coli isolates were also screened for the presence of the genetic determinants of resistance including ermB (macrolide resistance, tet(M (tetracycline resistance, and β-lactamases (blaOXA, blaSHV, and blaPSE. E. coli from urban waterways showed a greater incidence of antibiotic resistance to 8 of 17 antibiotics tested compared to human derived sources. These E. coli isolates also demonstrated a greater incidence of resistance to higher numbers of antibiotics compared to the human derived isolates. The urban waterways demonstrated a greater abundance of isolates with co-occurrence of antibiotic resistance than human derived sources. When screened for 5 different antibiotic resistance genes conferring macrolide, tetracycline, and β-lactam resistance, clinical E. coli isolates were more likely to harbor ermB and blaOXA than isolates from urban waterway. These results indicate that Milwaukee’s urban waterways may select for a greater incidence of multiple antibiotic resistance organisms and likely harbor a different antibiotic resistance gene pool than clinical sources. The implications of this study are significant to understanding the presence of resistance in urban freshwater environments by supporting the idea that sediment from urban waterways serves as a reservoir of antibiotic resistance.

Oral Fosfomycin for the Treatment of Acute and Chronic Bacterial Prostatitis Caused by Multidrug-Resistant Escherichia coli

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George G. Zhanel

2018-01-01

Full Text Available Acute and chronic bacterial prostatitis in outpatients is commonly treated with oral fluoroquinolones; however, the worldwide dissemination of multidrug-resistant (MDR Escherichia coli has resulted in therapeutic failures with fluoroquinolones. We reviewed the literature regarding the use of oral fosfomycin in the treatment of acute and chronic prostatitis caused by MDR E. coli. All English-language references on PubMed from 1986 to June 2017, inclusive, were reviewed from the search “fosfomycin prostatitis.” Fosfomycin demonstrates potent in vitro activity against a variety of antimicrobial-resistant E. coli genotypes/phenotypes including ciprofloxacin-resistant, trimethoprim-sulfamethoxazole-resistant, extended-spectrum β-lactamase- (ESBL- producing, and MDR isolates. Fosfomycin attains therapeutic concentrations (≥4 μg/g in uninflamed prostatic tissue and maintains a high prostate/plasma ratio up to 17 hours after oral administration. Oral fosfomycin’s clinical cure rates in the treatment of bacterial prostatitis caused by antimicrobial-resistant E. coli ranged from 50 to 77% with microbiological eradication rates of >50%. An oral regimen of fosfomycin tromethamine of 3 g·q 24 h for one week followed by 3 g·q 48 h for a total treatment duration of 6–12 weeks appeared to be effective. Oral fosfomycin may represent an efficacious and safe treatment for acute and chronic prostatitis caused by MDR E. coli.

Surveillance of ESBL producing multidrug resistant Escherichia coli in a teaching hospital in India

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Shakti Rath

2014-04-01

Full Text Available Objective: To record nosocomial and community-acquired accounts of antibiotic resistance in Escherichia coli (E. coli strains, isolated from clinical samples of a teaching hospital by surveillance, over a period of 39 months (November 2009-January 2013. Methods: Clinical samples from nosocomial sources, i.e., wards and cabins, intensive care unit (ICU and neonatal intensive care unit (NICU, and community (outpatient department, OPD sources of the hospital, were used for isolating strains of E. coli, which were subjected for testing for production of ‘extended spectrum beta-lactamase’-(ESBL enzyme as well as determining antibiotic sensitivity pattern with 23 antibiotics. Results: Of the total 1642 (100% isolates, 810 (49.33% strains were from OPD and 832 (50.66% were from hospital settings. Occurrence of infectious E. coli strains increased in a mathematical progression in community sources, but in nosocomial infections, such values remained almost constant in each quarter. A total of 395 (24.05% ESBL strains were isolated from the total 810 isolates of community; of the total of 464 (28.25% isolates of wards and cabins, 199 (12.11% were ESBL strains; and among the total of 368 (22.41% isolates of ICU and NICU, ESBLs were 170 (10.35%; the total nosocomial ESBL isolates, 369 (22.47% were from the nosocomial total of 832 (50.66% isolates. Statistically, it was confirmed that ESBL strains were equally distributed in community or hospital units. Antibiogram of 23 antibiotics revealed progressive increases of drug-resistance against each antibiotic with the maximum resistance values were recorded against gentamicin: 92% and 79%, oxacillin: 94% and 69%, ceftriaxone: 85% and 58%, and norfloxacin 97% and 69% resistance, in nosocomial and community isolates, respectively. Conclusions: This study revealed the daunting state of occurrence of multidrug resistant E. coli and its infection dynamics in both community and hospital settings.

Integrons in Escherichia coli from food-producing animals in The Netherlands

NARCIS (Netherlands)

Box, A.T.; Mevius, D.J.; Schellen, P.; Verhoef, J.; Fluit, A.C.

2005-01-01

The presence and character of class 1 integrons in multidrug-resistant Escherichia coli from slaughter animals and meat was determined by integrase-specific PCR and conserved segment PCR-restriction fragment length polymorphism (RFLP). At least five different class 1 integron types were found and

Seagulls and beaches as reservoirs for multidrug-resistant Escherichia coli.

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Simões, Roméo Rocha; Poirel, Laurent; Da Costa, Paulo Martins; Nordmann, Patrice

2010-01-01

A variety of extended-spectrum Beta-lactamase-producing Escherichia coli isolates, with a high rate of cefotaximase-15 resistance, were identified in seagull feces from Porto, Portugal, beaches. Beaches may therefore present a risk to public health because of the potential pathogen-spreading capacity of migratory birds.

Seagulls and Beaches as Reservoirs for Multidrug-Resistant Escherichia coli

OpenAIRE

Simões, Roméo Rocha; Poirel, Laurent; Da Costa, Paulo Martins; Nordmann, Patrice

2009-01-01

A variety of extended-spectrum ?-lactamase?producing Escherichia coli isolates, with a high rate of cefotaximase-15 resistance, were identified in seagull feces from Porto, Portugal, beaches. Beaches may therefore present a risk to public health because of the potential pathogen-spreading capacity of migratory birds.

Resistência a antimicrobianos dependente do sistema de efluxo multidrogas em Escherichia coli isoladas de leite mastítico Antimicrobial resistance dependent on multidrugs efflux in Escherichia coli isolated from the mastitic milk

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M.A.S. Moreira

2008-12-01

Full Text Available Identificaram-se e caracterizaram-se a resistência e a multirresistência aos principais antimicrobianos usados no tratamento de mastite bovina causada por Escherichia coli. A concentração inibitória mínima (MIC e o sistema de efluxo foram detectados pelas curvas de crescimento, com base na densidade óptica, em diferentes concentrações da droga e na presença e na ausência do desacoplador da força próton-motora (PMF. E. coli 1 foi resistente à neomicina e à gentamicina; E. coli 3 e 4, à tetraciclina e à estreptomicina; e E. coli 2 e 6 à gentamicina. E. coli 5 apresentou modelo de sensibilidade. Observou-se que MICs de todos os antimicrobianos dos multirresistentes (E. coli 1, 3 e 4 diminuíram na presença do desacoplador, o que sugere sistema de efluxo multidrogas. Após cura, apenas E. coli 1 apresentou modelo de sensibilidade, porém não houve alterações das MICs, antes e após adição do desacoplador. Os resultados indicam possível presença de mecanismo de resistência dependente da PMF codificado, ou parte dele, em plasmídeo.Resistance and multiresistance to main antimicrobials used for treating bovine mastitis caused by Escherichia coli were identified and characterized. The minimal inhibitory concentration (MIC and efflux systems were detected by the use of growth curves based on optical density at different drug concentrations and both presence and absence of uncoupler of the proton-motive force (PMF. E. coli 1 was resistant to neomycin and gentamycin, E. coli 3 and 4 were resistant to tetracycline and streptomycin, whereas E. coli 2 and 6 were resistant to gentamycin. E. coli 5 showed sensibility model. MICs of all antimicrobials of the multiresistant samples (E. coli 1, 3, and 4 were decreased in presence of the uncoupler, therefore suggesting the presence of the multidrug efflux system. After healing, only E. coli 1 showed sensibility model, however no alteration occurred in MIC(s before and after adding the

The Prevalence of the OqxAB Multidrug Efflux Pump amongst Olaquindox-Resistant Escherichia coli in Pigs

DEFF Research Database (Denmark)

Hansen, Lars Hestbjerg; Sørensen, Søren Johannes; Jørgensen, Helle S.

2005-01-01

The quinoxaline olaquindox has been used extensively as a growth promoter for pigs. Recently, we isolated a plasmid (pOLA52) conferring resistance to olaquindox from swine manure. On this plasmid, the oqxA and oqxB genes encode an RND-family multidrug efflux pump, OqxAB. It facilitates resistance...... to olaquindox as well as resistance to other antimicrobials like chloramphenicol. In this study, 10 of the 556 (1.8%) previously isolated Escherichia coli strains were shown to have an MIC = 64 µg/ml olaquindox. In nine of the ten strains, the oqxA gene was detected. Sequencing of an internal fragment of oqx......A from the oqxA-positive strains showed no variation, indicating highly conserved oqxA genes. All of the oqxA-positive strains contain plasmids with replicons similar to that of pOLA52. It was verified by Southern hybridization that the oqxAB operon was situated on plasmids in most, if not all, resistant...

The prevalence of the OqxAB amongst olaquindox-resistant multidrug efflux pump Escherichia coli in pigs

DEFF Research Database (Denmark)

Hansen, L.H.; Sørensen, S.J.; Jørgensen, H.S.

2005-01-01

The quinoxaline olaquindox has been used extensively as a growth promoter for pigs. Recently, we isolated a plasmid (pOLA52) conferring resistance to olaquindox from swine manure. On this plasmid, the oqxA and oqxB genes encode an RND-family multidrug efflux pump, OqxAB. It facilitates resistance...... to olaquindox as well as resistance to other antimicrobials like chloramphenicol. In this study, 10 of the 556 (1.8%) previously isolated Escherichia coli strains were shown to have an MIC >= 64 mu g/ml olaquindox. In nine of the ten strains, the oqxA gene was detected. Sequencing of an internal fragment of oqx......A from the oqxA-positive strains showed no variation, indicating highly conserved oqxA genes. All of the oqxA-positive strains contain plasmids with replicons similar to that of pOLA52. It was verified by Southern hybridization that the oqxAB operon was situated on plasmids in most, if not all, resistant...

Multidrug-Resistant and Extended Spectrum Beta-Lactamase-Producing Escherichia coli in Dutch Surface Water and Wastewater.

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Hetty Blaak

Full Text Available The goal of the current study was to gain insight into the prevalence and concentrations of antimicrobial resistant (AMR Escherichia coli in Dutch surface water, and to explore the role of wastewater as AMR contamination source.The prevalence of AMR E. coli was determined in 113 surface water samples obtained from 30 different water bodies, and in 33 wastewater samples obtained at five health care institutions (HCIs, seven municipal wastewater treatment plants (mWWTPs, and an airport WWTP. Overall, 846 surface water and 313 wastewater E. coli isolates were analysed with respect to susceptibility to eight antimicrobials (representing seven different classes: ampicillin, cefotaxime, tetracycline, ciprofloxacin, streptomycin, sulfamethoxazole, trimethoprim, and chloramphenicol.Among surface water isolates, 26% were resistant to at least one class of antimicrobials, and 11% were multidrug-resistant (MDR. In wastewater, the proportions of AMR/MDR E. coli were 76%/62% at HCIs, 69%/19% at the airport WWTP, and 37%/27% and 31%/20% in mWWTP influents and effluents, respectively. Median concentrations of MDR E. coli were 2.2×10(2, 4.0×10(4, 1.8×10(7, and 4.1×10(7 cfu/l in surface water, WWTP effluents, WWTP influents and HCI wastewater, respectively. The different resistance types occurred with similar frequencies among E. coli from surface water and E. coli from municipal wastewater. By contrast, among E. coli from HCI wastewater, resistance to cefotaxime and resistance to ciprofloxacin were significantly overrepresented compared to E. coli from municipal wastewater and surface water. Most cefotaxime-resistant E. coliisolates produced ESBL. In two of the mWWTP, ESBL-producing variants were detected that were identical with respect to phylogenetic group, sequence type, AMR-profile, and ESBL-genotype to variants from HCI wastewater discharged onto the same sewer and sampled on the same day (A1/ST23/CTX-M-1, B23/ST131/CTX-M-15, D2/ST405/CTX-M-15.In

Population pharmacokinetics and pharmacodynamics of fosfomycin in non-critically ill patients with bacteremic urinary infection caused by multidrug-resistant Escherichia coli.

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Merino-Bohórquez, V; Docobo-Pérez, F; Sojo, J; Morales, I; Lupión, C; Martín, D; Cameán, M; Hope, W; Pascual, Á; Rodríguez-Baño, J

2018-04-10

To describe the population pharmacokinetics of fosfomycin for patients with bacteraemic urinary tract infection (BUTI). The analysis identified optimal regimens on the basis of pharmacodynamic targets and assessed the adequacy of Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) susceptibility breakpoints for Escherichia coli. Data of 16 patients with BUTI caused by multidrug-resistant E. coli (FOREST clinical trial) received intravenous fosfomycin (4 g every 6 hours) were analysed. A population pharmacokinetic analysis was performed, and Monte Carlo simulations were undertaken using 4 g every 6 hours and 8 g every 8 hours. The probability of pharmacodynamic target attainment was assessed using pharmacodynamic targets for E. coli for static effect, 1-log drop in bacterial burden and resistance suppression. Sixty-four plasma samples were collected over a single dosing interval (day 2 or 3 after starting fosfomycin treatment). Fosfomycin concentrations were highly variable. Pharmacodynamic target attainment analysis showed mild improvement by increasing fosfomycin dosing (4 g every 6 hours vs. every 8 hours). These dosages showed success for decreasing 1-log bacterial burden in 89% to 96% (EUCAST breakpoints) and 33% to 54% (CLSI breakpoints) of patients, but they were unable to reach bacterial resistance suppression targets. Fosfomycin concentrations are highly variable-a fact partially explained by renal impairment. The present work supports the use of 4 g every 6 hours as an effective regimen for the treatment of non-critically ill patients with BUTI caused by multidrug-resistant E. coli, as higher dosages might increase toxicity but may not significantly increase efficacy. The current information may suggest that fosfomycin susceptibility breakpoints need to be reappraised. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by

Isolation and evaluation of cocktail phages for the control of multidrug-resistant Escherichia coli serotype O104: H4 and E. coli O157: H7 isolates causing diarrhea.

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Safwat Mohamed, Doaa; Farouk Ahmed, Eman; Mohamed Mahmoud, Abobakr; Abd El-Baky, Rehab Mahmoud; John, James

2018-02-01

Escherichia coli serotype O157: H7 and E. coli O104: H4 are well known foodborne pathogens causing sever enteric illness. Using bacteriophages as biocontrol agents of some foodborne pathogens and multidrug-resistant (MDR) bacteria has a great attention nowadays. This study aims to test the effect of cocktail phages on the growth of some foodborne pathogens and MDR E. coli. Routine conventional PCR was used to confirm the identification of E. coli isolates. Double-layered culture technique was used to isolate phages from sewage water. Morphology of bacteriophage was described using transmission electron microscopy, and spot test was performed to determine host range of the phage cocktail. Phage cocktail of Siphoviridae and Podoviridae family infecting E. coli O157: H7, E. coli O104: H4 and untypeable E. coli (neither O157 nor O104) has been isolated from sewage water. Phage cocktail showed both lytic and lysogenic activity. Lytic activity was observed against E. coli O157: H7, E. coli O104: H4 isolates, Staphylococcus. aureus ATCC6538 and Pseudomonas aeruginosa ATCC 10145, while the lysogenic activity was observed against the untypeable strain. The tested phage cocktail showed a promising inhibitory action on E. coli O157: H7 and O104: H4, S. aureus ATCC6538 and P. aeruginosa ATCC 10145, suggesting the possibility of its use as a biocontrol tool or as natural food preservatives for many food products. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Escherichia coli pathotypes

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Escherichia coli strains are important commensals of the intestinal tract of humans and animals; however, pathogenic strains, including diarrhea-inducing E. coli and extraintestinal pathogenic E. coli. Intestinal E. coli pathotypes may cause a dehydrating watery diarrhea, or more severe diseases su...

Characterization of novel bacteriophage phiC119 capable of lysing multidrug-resistant Shiga toxin-producing Escherichia coli O157:H7

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Luis Amarillas

2016-09-01

Full Text Available Background Shiga toxin-producing Escherichia coli (STEC is one of the most common and widely distributed foodborne pathogens that has been frequently implicated in gastrointestinal and urinary tract infections. Moreover, high rates of multiple antibiotic-resistant E. coli strains have been reported worldwide. Due to the emergence of antibiotic-resistant strains, bacteriophages are considered an attractive alternative to biocontrol pathogenic bacteria. Characterization is a preliminary step towards designing a phage for biocontrol. Methods In this study, we describe the characterization of a bacteriophage designated phiC119, which can infect and lyse several multidrug-resistant STEC strains and some Salmonella strains. The phage genome was screened to detect the stx-genes using PCR, morphological analysis, host range was determined, and genome sequencing were carried out, as well as an analysis of the cohesive ends and identification of the type of genetic material through enzymatic digestion of the genome. Results Analysis of the bacteriophage particles by transmission electron microscopy showed that it had an icosahedral head and a long tail, characteristic of the family Siphoviridae. The phage exhibits broad host range against multidrug-resistant and highly virulent E. coli isolates. One-step growth experiments revealed that the phiC119 phage presented a large burst size (210 PFU/cell and a latent period of 20 min. Based on genomic analysis, the phage contains a linear double-stranded DNA genome with a size of 47,319 bp. The phage encodes 75 putative proteins, but lysogeny and virulence genes were not found in the phiC119 genome. Conclusion These results suggest that phage phiC119 may be a good biological control agent. However, further studies are required to ensure its control of STEC and to confirm the safety of phage use.

An In Vitro Chicken Gut Model Demonstrates Transfer of a Multidrug Resistance Plasmid from Salmonella to Commensal Escherichia coli.

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Card, Roderick M; Cawthraw, Shaun A; Nunez-Garcia, Javier; Ellis, Richard J; Kay, Gemma; Pallen, Mark J; Woodward, Martin J; Anjum, Muna F

2017-07-18

The chicken gastrointestinal tract is richly populated by commensal bacteria that fulfill various beneficial roles for the host, including helping to resist colonization by pathogens. It can also facilitate the conjugative transfer of multidrug resistance (MDR) plasmids between commensal and pathogenic bacteria which is a significant public and animal health concern as it may affect our ability to treat bacterial infections. We used an in vitro chemostat system to approximate the chicken cecal microbiota, simulate colonization by an MDR Salmonella pathogen, and examine the dynamics of transfer of its MDR plasmid harboring several genes, including the extended-spectrum beta-lactamase bla CTX-M1 We also evaluated the impact of cefotaxime administration on plasmid transfer and microbial diversity. Bacterial community profiles obtained by culture-independent methods showed that Salmonella inoculation resulted in no significant changes to bacterial community alpha diversity and beta diversity, whereas administration of cefotaxime caused significant alterations to both measures of diversity, which largely recovered. MDR plasmid transfer from Salmonella to commensal Escherichia coli was demonstrated by PCR and whole-genome sequencing of isolates purified from agar plates containing cefotaxime. Transfer occurred to seven E. coli sequence types at high rates, even in the absence of cefotaxime, with resistant strains isolated within 3 days. Our chemostat system provides a good representation of bacterial interactions, including antibiotic resistance transfer in vivo It can be used as an ethical and relatively inexpensive approach to model dissemination of antibiotic resistance within the gut of any animal or human and refine interventions that mitigate its spread before employing in vivo studies. IMPORTANCE The spread of antimicrobial resistance presents a grave threat to public health and animal health and is affecting our ability to respond to bacterial infections

Contribution of AcrAB-ToIC to multidrug resistance in an Escherichia coli sequence type 131 isolate

NARCIS (Netherlands)

Schuster, Sabine; Vavra, Martina; Schweigger, Tobias M.; Rossen, John W. A.; Matsumura, Yasufumi; Kern, Winfried V.

Drug efflux by resistance-nodulation-cell division (RND)-type transporters, such as AcrAB-ToIC of Escherichia can, is an important resistance mechanism in Gram-negative bacteria; however, its contribution to multidrug resistance (MDR) in clinical isolates is poorly defined. We inactivated acrB of a

Multidrug resistant commensal Escherichia coli in animals and its impact for public health

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Ama eSzmolka

2013-09-01

Full Text Available After the era of plentiful antibiotics we are alarmed by the increasing number of antibiotic resistant strains. The genetic flexibility and adaptability of E. coli to constantly changing environments allows to acquire a great number of antimicrobial resistance mechanisms. Commensal strains of E. coli as versatile residents of the lower intestine are also repeatedly challenged by antimicrobial pressures during the lifetime of their host. As a consequence, commensal strains acquire the respective resistance genes, and/or develop resistant mutants in order to survive and maintain microbial homeostasis in the lower intestinal tract. Thus, commensal E. coli strains are regarded as indicators of antimicrobial load on their hosts. This chapter provides a short historic background of the appearance and presumed origin and transfer of antimicrobial resistance genes in commensal intestinal E. coli of animals with comparative information on their pathogenic counterparts. The dynamics, development and ways of evolution of resistance in the E. coli populations differ according to hosts, resistance mechanisms and antimicrobial classes used. The most frequent tools of E. coli against a variety of antimicrobials are the efflux pumps and mobile resistance mechanisms carried by plasmids and/or other transferable elements. The emergence of hybrid plasmids (both resistance and virulence among E. coli is of further concern. Co-existence and co-transfer of these bad genes in this huge and most versatile in vivo compartment may represent an increased public health risk in the future. Significance of multidrug resistant (MDR commensal E. coli seem to be highest in the food animal industry, acting as reservoir for intra- and interspecific exchange and a source for spread of MDR determinants through contaminated food to humans. Thus, public health potential of MDR commensal E. coli of food animals can be a concern and needs monitoring and more molecular analysis in the

Diversity of Multi-Drug Resistant Avian Pathogenic Escherichia coli (APEC) Causing Outbreaks of Colibacillosis in Broilers during 2012 in Spain.

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Solà-Ginés, Marc; Cameron-Veas, Karla; Badiola, Ignacio; Dolz, Roser; Majó, Natalia; Dahbi, Ghizlane; Viso, Susana; Mora, Azucena; Blanco, Jorge; Piedra-Carrasco, Nuria; González-López, Juan José; Migura-Garcia, Lourdes

2015-01-01

Avian pathogenic Escherichia coli (APEC) are the major cause of colibacillosis in poultry production. In this study, a total of 22 E. coli isolated from colibacillosis field cases and 10 avian faecal E. coli (AFEC) were analysed. All strains were characterised phenotypically by susceptibility testing and molecular typing methods such as pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). The presence of 29 virulence genes associated to APEC and human extraintestinal pathogenic E. coli (ExPEC) was also evaluated. For cephalosporin resistant isolates, cephalosporin resistance genes, plasmid location and replicon typing was assessed. Avian isolates belonged to 26 O:H serotypes and 24 sequence types. Out of 22 APEC isolates, 91% contained the virulence genes predictors of APEC; iutA, hlyF, iss, iroN and ompT. Of all strains, 34% were considered ExPEC. PFGE analysis demonstrated a high degree of genetic polymorphism. All strains were multi-resistant, including those isolated from healthy animals. Eleven strains were resistant to cephalosporins; six contained blaCTX-M-14, two blaSHV-12, two blaCMY-2 and one blaSHV-2. Two strains harboured qnrA, and two qnrA together with aac(6')-Ib-cr. Additionally, the emergent clone O25b:H4-B2-ST131 was isolated from a healthy animal which harboured blaCMY-2 and qnrS genes. Cephalosporin resistant genes were mainly associated to the presence of IncK replicons. This study demonstrates a very diverse population of multi-drug resistant E. coli containing a high number of virulent genes. The E. coli population among broilers is a reservoir of resistance and virulence-associated genes that could be transmitted into the community through the food chain. More epidemiological studies are necessary to identify clonal groups and resistance mechanisms with potential relevance to public health.

Diversity of Multi-Drug Resistant Avian Pathogenic Escherichia coli (APEC Causing Outbreaks of Colibacillosis in Broilers during 2012 in Spain.

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Marc Solà-Ginés

Full Text Available Avian pathogenic Escherichia coli (APEC are the major cause of colibacillosis in poultry production. In this study, a total of 22 E. coli isolated from colibacillosis field cases and 10 avian faecal E. coli (AFEC were analysed. All strains were characterised phenotypically by susceptibility testing and molecular typing methods such as pulsed-field gel electrophoresis (PFGE and multi-locus sequence typing (MLST. The presence of 29 virulence genes associated to APEC and human extraintestinal pathogenic E. coli (ExPEC was also evaluated. For cephalosporin resistant isolates, cephalosporin resistance genes, plasmid location and replicon typing was assessed. Avian isolates belonged to 26 O:H serotypes and 24 sequence types. Out of 22 APEC isolates, 91% contained the virulence genes predictors of APEC; iutA, hlyF, iss, iroN and ompT. Of all strains, 34% were considered ExPEC. PFGE analysis demonstrated a high degree of genetic polymorphism. All strains were multi-resistant, including those isolated from healthy animals. Eleven strains were resistant to cephalosporins; six contained blaCTX-M-14, two blaSHV-12, two blaCMY-2 and one blaSHV-2. Two strains harboured qnrA, and two qnrA together with aac(6'-Ib-cr. Additionally, the emergent clone O25b:H4-B2-ST131 was isolated from a healthy animal which harboured blaCMY-2 and qnrS genes. Cephalosporin resistant genes were mainly associated to the presence of IncK replicons. This study demonstrates a very diverse population of multi-drug resistant E. coli containing a high number of virulent genes. The E. coli population among broilers is a reservoir of resistance and virulence-associated genes that could be transmitted into the community through the food chain. More epidemiological studies are necessary to identify clonal groups and resistance mechanisms with potential relevance to public health.

Phenotypic Characterization of Multidrug-resistant Escherichia Coli with Special Reference to Extended-spectrum-beta-lactamases and Metallo-beta-lactamases in a Tertiary Care Center

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Basudha Shrestha

2015-06-01

Conclusions: Beta-lactamase mediated resistance mechanisms are accounting very high in the multidrug resistant isolates of E. coli. Therefore, early detection of beta lactamase mediated resistant strains and their current antibiotic susceptibility pattern is necessary to avoid treatment failure and prevent the spread of MDR. Keywords: e. coli; extended-spectrum-β-lactamase; metallo-β-lactamase; multidrug-resistance.

Genetic Structure and Antimicrobial Resistance of Escherichia coli and Cryptic Clades in Birds with Diverse Human Associations.

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Blyton, Michaela D J; Pi, Hongfei; Vangchhia, Belinda; Abraham, Sam; Trott, Darren J; Johnson, James R; Gordon, David M

2015-08-01

The manner and extent to which birds associate with humans may influence the genetic attributes and antimicrobial resistance of their commensal Escherichia communities through strain transmission and altered selection pressures. In this study, we determined whether the distribution of the different Escherichia coli phylogenetic groups and cryptic clades, the occurrence of 49 virulence associated genes, and/or the prevalence of resistance to 12 antimicrobials differed between four groups of birds from Australia with contrasting types of human association. We found that birds sampled in suburban and wilderness areas had similar Escherichia communities. The Escherichia communities of backyard domestic poultry were phylogenetically distinct from the Escherichia communities sourced from all other birds, with a large proportion (46%) of poultry strains belonging to phylogenetic group A and a significant minority (17%) belonging to the cryptic clades. Wild birds sampled from veterinary and wildlife rehabilitation centers (in-care birds) carried Escherichia isolates that possessed particular virulence-associated genes more often than Escherichia isolates from birds sampled in suburban and wilderness areas. The Escherichia isolates from both the backyard poultry and in-care birds were more likely to be multidrug resistant than the Escherichia isolates from wild birds. We also detected a multidrug-resistant E. coli strain circulating in a wildlife rehabilitation center, reinforcing the importance of adequate hygiene practices when handling and caring for wildlife. We suggest that the relatively high frequency of antimicrobial resistance in the in-care birds and backyard poultry is due primarily to the use of antimicrobials in these animals, and we recommend that the treatment protocols used for these birds be reviewed. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Conjugation in Escherichia coli

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Boyer, Herbert

1966-01-01

Boyer, Herbert (Yale University, New Haven, Conn.). Conjugation in Escherichia coli. J. Bacteriol. 91:1767–1772. 1966.—The sex factor of Escherichia coli K-12 was introduced into an E. coli B/r strain by circumventing the host-controlled modification and restriction incompatibilities known to exist between these closely related strains. The sexual properties of the constructed F+ B strain and its Hfr derivatives were examined. These studies showed that the E. coli strain B/r F+ and Hfr derivatives are similar to the E. coli strain K-12 F+ and Hfr derivatives. However, the site of sex factor integration was found to be dependent on the host genome. PMID:5327905

Occurance and characteristics of class 1, 2 and 3 integrons in Escherichia coli, Salmonella and Campylobacter spp. in the Netherlands

NARCIS (Netherlands)

Essen-Zandbergen, van A.; Smith, H.E.; Veldman, K.T.; Mevius, D.J.

2007-01-01

Objectives: To determine the occurrence and transmission of class 1, 2 and 3 integrons in multidrug-resistant or sulfamethoxazole-resistant Salmonella from human and animal sources and in Campylobacter spp. and Escherichia coli from broilers isolated in the Netherlands in 2004. Methods: PCR,

Determination Pattern of Antibiotic Resistance in Entropathogenic Escherichia coli Strains Isolated from Children with Diarrhea

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P. Karami

2012-04-01

Full Text Available Introduction & Objective: Diarrheal diseases are considered a major health problem, especially in children. Enteropathogenic Escherichia coli (EPEC strains are the common cause of diarrhea in children especially in developing countries. Because of undesirable effects of diarrhea and its interference with children's growth, in some cases antibiotic treatment is recommended. In recent years, resistance toward common and effective antibiotics in the treatment of infectious diseases became one of the most important challenges in medical society, for this purpose, antibiotic sensitivity and resistance of strains in every geographical zone must be determined. So in this study, of antibiotic patterns of these bacteria were examined.Materials & Methods: This cross-sectional study was performed on 192 strains of Enteropathogen Escherichia coli isolated from children who were suffering from diarrhea in 1389-1390 in the microbiology laboratory of Hamadan University of medical sciences. To identify these strains, standard biochemical and serology tests were used. The antibiotic sensitivity test of these isolates was carried out with disc diffusion agar method according to the CLSI standards for 14 different antibiotics disc. Resistance toward 3 or more than 3 classes of antibiotics were defined as multidrug resistance.Results: The result of this study shows EPEC strains had the highest resistance to cefpodoxime (97%, trimethoprim (60.7%, tetracycline (58.4% and ampicillin (45.8%. Multidrug resistance was 68.7 percent. These strains also showed the highest sensitivity against imipenem, ceftriaxone, and ciprofloxacin antibiotics.Conclusion: EPEC strains that were studied with resistance to ampicillin, tetracycline and convenient sensitivity against fluoroquinolones are one of the major factors in children’s diarrhea. A result of this research suggests that antimicrobial resistance in Escherichia coli strains are high and prescribing and antibiotic is not

21 CFR 866.3255 - Escherichia coli serological reagents.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Escherichia coli serological reagents. 866.3255... coli serological reagents. (a) Identification. Escherichia coli serological reagents are devices that consist of antigens and antisera used in serological tests to identify Escherichia coli from cultured...

pH-induced conformational changes of AcrA, the membrane fusion protein of Escherichia coli multidrug efflux system.

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Ip, Hermia; Stratton, Kelly; Zgurskaya, Helen; Liu, Jun

2003-12-12

The multidrug efflux system AcrA-AcrB-TolC of Escherichia coli expels a wide range of drugs directly into the external medium from the bacterial cell. The mechanism of the efflux process is not fully understood. Of an elongated shape, AcrA is thought to span the periplasmic space coordinating the concerted operation of the inner and outer membrane proteins AcrB and TolC. In this study, we used site-directed spin labeling (SDSL) EPR (electron paramagnetic resonance) spectroscopy to investigate the molecular conformations of AcrA in solution. Ten AcrA mutants, each with an alanine to cysteine substitution, were engineered, purified, and labeled with a nitroxide spin label. EPR analysis of spin-labeled AcrA variants indicates that the side chain mobilities are consistent with the predicted secondary structure of AcrA. We further demonstrated that acidic pH induces oligomerization and conformational change of AcrA, and that the structural changes are reversible. These results suggest that the mechanism of action of AcrA in drug efflux is similar to the viral membrane fusion proteins, and that AcrA actively mediates the efflux of substrates.

Risk of Transmission of Antimicrobial Resistant Escherichia coli from Commercial Broiler and Free-Range Retail Chicken in India.

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Hussain, Arif; Shaik, Sabiha; Ranjan, Amit; Nandanwar, Nishant; Tiwari, Sumeet K; Majid, Mohammad; Baddam, Ramani; Qureshi, Insaf A; Semmler, Torsten; Wieler, Lothar H; Islam, Mohammad A; Chakravortty, Dipshikha; Ahmed, Niyaz

2017-01-01

Multidrug-resistant Escherichia coli infections are a growing public health concern. This study analyzed the possibility of contamination of commercial poultry meat (broiler and free-range) with pathogenic and or multi-resistant E. coli in retail chain poultry meat markets in India. We analyzed 168 E. coli isolates from broiler and free-range retail poultry (meat/ceca) sampled over a wide geographical area, for their antimicrobial sensitivity, phylogenetic groupings, virulence determinants, extended-spectrum-β-lactamase (ESBL) genotypes, fingerprinting by Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR and genetic relatedness to human pathogenic E. coli using whole genome sequencing (WGS). The prevalence rates of ESBL producing E. coli among broiler chicken were: meat 46%; ceca 40%. Whereas, those for free range chicken were: meat 15%; ceca 30%. E. coli from broiler and free-range chicken exhibited varied prevalence rates for multi-drug resistance (meat 68%; ceca 64% and meat 8%; ceca 26%, respectively) and extraintestinal pathogenic E. coli (ExPEC) contamination (5 and 0%, respectively). WGS analysis confirmed two globally emergent human pathogenic lineages of E. coli , namely the ST131 ( H 30-Rx subclone) and ST117 among our poultry E. coli isolates. These results suggest that commercial poultry meat is not only an indirect public health risk by being a possible carrier of non-pathogenic multi-drug resistant (MDR)- E. coli , but could as well be the carrier of human E. coli pathotypes. Further, the free-range chicken appears to carry low risk of contamination with antimicrobial resistant and extraintestinal pathogenic E. coli (ExPEC). Overall, these observations reinforce the understanding that poultry meat in the retail chain could possibly be contaminated by MDR and/or pathogenic E. coli.

Heterologously expressed bacterial and human multidrug resistance proteins confer cadmium resistance to Escherichia coli

NARCIS (Netherlands)

Achard-Joris, M; van Saparoea, HBV; Driessen, AJM; Bourdineaud, JP; Bourdineaud, Jean-Paul

2005-01-01

The human MDR1 gene is induced by cadmium exposure although no resistance to this metal is observed in human cells overexpressing hMDR1. To access the role of MDR proteins in cadmium resistance, human MDR1, Lactococcus lactis lmrA, and Oenococcus oeni omrA were expressed in an Escherichia coli tolC

The complete genome sequence of Escherichia coli EC958: a high quality reference sequence for the globally disseminated multidrug resistant E. coli O25b:H4-ST131 clone.

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Brian M Forde

Full Text Available Escherichia coli ST131 is now recognised as a leading contributor to urinary tract and bloodstream infections in both community and clinical settings. Here we present the complete, annotated genome of E. coli EC958, which was isolated from the urine of a patient presenting with a urinary tract infection in the Northwest region of England and represents the most well characterised ST131 strain. Sequencing was carried out using the Pacific Biosciences platform, which provided sufficient depth and read-length to produce a complete genome without the need for other technologies. The discovery of spurious contigs within the assembly that correspond to site-specific inversions in the tail fibre regions of prophages demonstrates the potential for this technology to reveal dynamic evolutionary mechanisms. E. coli EC958 belongs to the major subgroup of ST131 strains that produce the CTX-M-15 extended spectrum β-lactamase, are fluoroquinolone resistant and encode the fimH30 type 1 fimbrial adhesin. This subgroup includes the Indian strain NA114 and the North American strain JJ1886. A comparison of the genomes of EC958, JJ1886 and NA114 revealed that differences in the arrangement of genomic islands, prophages and other repetitive elements in the NA114 genome are not biologically relevant and are due to misassembly. The availability of a high quality uropathogenic E. coli ST131 genome provides a reference for understanding this multidrug resistant pathogen and will facilitate novel functional, comparative and clinical studies of the E. coli ST131 clonal lineage.

Gallic acid-based indanone derivative interacts synergistically with tetracycline by inhibiting efflux pump in multidrug resistant E. coli.

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Dwivedi, Gaurav Raj; Tiwari, Nimisha; Singh, Aastha; Kumar, Akhil; Roy, Sudeep; Negi, Arvind Singh; Pal, Anirban; Chanda, Debabrata; Sharma, Ashok; Darokar, Mahendra P

2016-03-01

The purpose of the present study was to study the synergy potential of gallic acid-based derivatives in combination with conventional antibiotics using multidrug resistant cultures of Escherichia coli. Gallic acid-based derivatives significantly reduced the MIC of tetracycline against multidrug resistant clinical isolate of E. coli. The best representative, 3-(3',4,'5'-trimethoxyphenyl)-4,5,6-trimethoxyindanone-1, an indanone derivative of gallic acid, was observed to inhibit ethidium bromide efflux and ATPase which was also supported by in silico docking. This derivative extended the post-antibiotic effect and decreased the mutation prevention concentration of tetracycline. This derivative in combination with TET was able to reduce the concentration of TNFα up to 18-fold in Swiss albino mice. This derivative was nontoxic and well tolerated up to 300 mg/kg dose in subacute oral toxicity study in mice. This is the first report of gallic acid-based indanone derivative as drug resistance reversal agent acting through ATP-dependent efflux pump inhibition.

Risk of Transmission of Antimicrobial Resistant Escherichia coli from Commercial Broiler and Free-Range Retail Chicken in India

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Arif Hussain

2017-11-01

Full Text Available Multidrug-resistant Escherichia coli infections are a growing public health concern. This study analyzed the possibility of contamination of commercial poultry meat (broiler and free-range with pathogenic and or multi-resistant E. coli in retail chain poultry meat markets in India. We analyzed 168 E. coli isolates from broiler and free-range retail poultry (meat/ceca sampled over a wide geographical area, for their antimicrobial sensitivity, phylogenetic groupings, virulence determinants, extended-spectrum-β-lactamase (ESBL genotypes, fingerprinting by Enterobacterial Repetitive Intergenic Consensus (ERIC PCR and genetic relatedness to human pathogenic E. coli using whole genome sequencing (WGS. The prevalence rates of ESBL producing E. coli among broiler chicken were: meat 46%; ceca 40%. Whereas, those for free range chicken were: meat 15%; ceca 30%. E. coli from broiler and free-range chicken exhibited varied prevalence rates for multi-drug resistance (meat 68%; ceca 64% and meat 8%; ceca 26%, respectively and extraintestinal pathogenic E. coli (ExPEC contamination (5 and 0%, respectively. WGS analysis confirmed two globally emergent human pathogenic lineages of E. coli, namely the ST131 (H30-Rx subclone and ST117 among our poultry E. coli isolates. These results suggest that commercial poultry meat is not only an indirect public health risk by being a possible carrier of non-pathogenic multi-drug resistant (MDR-E. coli, but could as well be the carrier of human E. coli pathotypes. Further, the free-range chicken appears to carry low risk of contamination with antimicrobial resistant and extraintestinal pathogenic E. coli (ExPEC. Overall, these observations reinforce the understanding that poultry meat in the retail chain could possibly be contaminated by MDR and/or pathogenic E. coli.

PATHOGENIC POTENTIALS OF ESCHERICHIA COLI ISOLATED ...

African Journals Online (AJOL)

Electrolyte and haematological parameters in rabbits infected with pathogenic isolates of Escherichia coli from rural water supplies in Rivers State, Nigeria, where monitored. Rabbits were orally infected with suspension containing 3x107 cfu /ml of Escherichia coli to induce diarrhoea, and the electrolyte (sodium, potassium ...

77 FR 9888 - Shiga Toxin-Producing Escherichia coli

Science.gov (United States)

2012-02-21

... Toxin-Producing Escherichia coli in Certain Raw Beef Products AGENCY: Food Safety and Inspection Service... toxin-producing Escherichia coli (STEC) serogroups (O26, O45, O103, O111, O121, and O145). This new date..., that are contaminated with Shiga toxin-producing Escherichia coli (STEC) O26, O45, O103, O111, O121...

Cloacael Carriage and Multidrug Resistance Escherichia coli O157:H7 from Poultry Farms, Eastern Ethiopia.

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Shecho, Mude; Thomas, Naod; Kemal, Jelalu; Muktar, Yimer

2017-01-01

A cross-sectional study was carried out to determine antimicrobial drug resistance patterns of E. coli O157:H7 isolates and estimate the level of the pathogen. A total of 194 cloacae swab samples were collected randomly in two poultry farms. Standard cultural, biochemical, and serological (latex agglutination) methods were used to isolate E. coli O157:H7. The isolates were subjected to antimicrobial susceptibility testing using disc diffusion method. Out of 194 cloacae samples examined, 13.4% ( n = 26) were found to be positive for E. coli O157:H7. The finding indicated differences in E. coli O157:H7 infection among the different risk factors. Chicken from Adele Poultry Farm showed higher E. coli O157:H7 infection (OR = 3.89) than Haramaya University poultry farm and young birds had more infection (OR = 4.62) than adult birds. Of the total 14 antimicrobials included in the panel of study, the susceptibility results were varied with 96.15% and 0% E. coli O157:H7 isolates expressing resistance to erythromycin, clindamycin, spectinomycin, and ciprofloxacin, respectively. Multidrug resistance to more than two antimicrobial agents was detected in 24 (92.30%) of the isolates. The study showed high presence of antimicrobial resistant isolates of E. coli O157:H7. Further study is required to better understand the ecology and evolution of bacterial resistance to antimicrobial agents.

Cloacael Carriage and Multidrug Resistance Escherichia coli O157:H7 from Poultry Farms, Eastern Ethiopia

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Mude Shecho

2017-01-01

Full Text Available A cross-sectional study was carried out to determine antimicrobial drug resistance patterns of E. coli O157:H7 isolates and estimate the level of the pathogen. A total of 194 cloacae swab samples were collected randomly in two poultry farms. Standard cultural, biochemical, and serological (latex agglutination methods were used to isolate E. coli O157:H7. The isolates were subjected to antimicrobial susceptibility testing using disc diffusion method. Out of 194 cloacae samples examined, 13.4% (n=26 were found to be positive for E. coli O157:H7. The finding indicated differences in E. coli O157:H7 infection among the different risk factors. Chicken from Adele Poultry Farm showed higher E. coli O157:H7 infection (OR = 3.89 than Haramaya University poultry farm and young birds had more infection (OR = 4.62 than adult birds. Of the total 14 antimicrobials included in the panel of study, the susceptibility results were varied with 96.15% and 0% E. coli O157:H7 isolates expressing resistance to erythromycin, clindamycin, spectinomycin, and ciprofloxacin, respectively. Multidrug resistance to more than two antimicrobial agents was detected in 24 (92.30% of the isolates. The study showed high presence of antimicrobial resistant isolates of E. coli O157:H7. Further study is required to better understand the ecology and evolution of bacterial resistance to antimicrobial agents.

Detection of Class I and II integrons for the assessment of antibiotic and multidrug resistance among Escherichia coli isolates from agricultural irrigation waters in Bulacan, Philippines.

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Paraoan, Cielo Emar M; Rivera, Windell L; Vital, Pierangeli G

2017-05-04

Contaminated irrigation water may greatly affect not only the quality of produce but also the people exposed to it. In this study, agricultural irrigation waters in Bulacan, Philippines were assessed and found to be contaminated with Escherichia coli (E. coli) ranging from 0.58 to 4.51 log 10 CFU/mL. A total of 79 isolates of E. coli were confirmed through polymerase chain reaction (PCR) amplifying the uidA gene and were tested for phenotypic resistance using 10 antimicrobials through the Kirby-Bauer disc diffusion method. Forty-six isolates (58.22%) were noted to be multidrug resistant (MDR) with high resistance rate to cephalothin, tetracycline, streptomycin, ampicillin, trimethoprim, nalidixic acid, and chloramphenicol. Moreover, this study also examined the prevalence of Class I and II integrons accounting to 67.39% and 17.39%, respectively, of the MDR E. coli strains using multiplex PCR. The results imply that the agricultural water used in Bulacan is contaminated with the fecal material of man or other animals present in the area, and the presence of MDR bacteria, which pose a potential threat to individuals in these areas, is alarming. In addition, detection of integrons could be a good marker for the identification of MDR isolates. Lastly, this study could develop strategies for the proper management of farming sites leading to the detection of food-borne pathogens and prevention of infectious diseases.

Presence of Type I-F CRISPR/Cas systems is associated with antimicrobial susceptibility in Escherichia coli.

OpenAIRE

Aydin, Seyid; Personne, Yoann; Newire, Enas; Laverick, Rebecca; Russell, Oliver; Roberts, Adam; Enne, Virve I

2017-01-01

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and their associated cas genes are sequence-specific DNA nuclease systems found in bacteria and archaea. CRISPR/Cas systems use RNA transcripts of previously acquired DNA (spacers) to target invading genetic elements with the same sequence, including plasmids. In this research we studied the relationship between CRISPR/Cas systems and multidrug resistance in Escherichia coli . The presence of Type I-E and Type I-F CRISPR syste...

Escherichia coli Sequence Type 131 H30 Is the Main Driver of Emerging Extended-Spectrum-β-Lactamase-Producing E. coli at a Tertiary Care Center.

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Johnson, James R; Johnston, Brian; Thuras, Paul; Launer, Bryn; Sokurenko, Evgeni V; Miller, Loren G

2016-01-01

The H 30 strain of Escherichia coli sequence type 131 (ST131- H 30) is a recently emerged, globally disseminated lineage associated with fluoroquinolone resistance and, via its H 30Rx subclone, the CTX-M-15 extended-spectrum beta-lactamase (ESBL). Here, we studied the clonal background and resistance characteristics of 109 consecutive recent E. coli clinical isolates (2015) and 41 historical ESBL-producing E. coli blood isolates (2004 to 2011) from a public tertiary care center in California with a rising prevalence of ESBL-producing E. coli isolates. Among the 2015 isolates, ST131, which was represented mainly by ST131- H 30, was the most common clonal lineage (23% overall). ST131- H 30 accounted for 47% (8/17) of ESBL-producing, 47% (14/30) of fluoroquinolone-resistant, and 33% (11/33) of multidrug-resistant isolates. ST131- H 30 also accounted for 53% (8/14) of dually fluoroquinolone-resistant, ESBL-producing isolates, with the remaining 47% comprised of diverse clonal groups that contributed a single isolate each. ST131- H 30Rx, with CTX-M-15, was the major ESBL producer (6/8) among ST131- H 30 isolates. ST131- H 30 and H 30Rx also dominated (46% and 37%, respectively) among the historical ESBL-producing isolates (2004 to 2011), without significant temporal shifts in relative prevalence. Thus, this medical center's recently emerging ESBL-producing E. coli strains, although multiclonal, are dominated by ST131- H 30 and H 30Rx, which are the only clonally expanded fluoroquinolone-resistant, ESBL-producing lineages. Measures to rapidly and effectively detect, treat, and control these highly successful lineages are needed. IMPORTANCE The ever-rising prevalence of resistance to first-line antibiotics among clinical Escherichia coli isolates leads to worse clinical outcomes and higher health care costs, thereby creating a need to discover its basis so that effective interventions can be developed. We found that the H 30 subset within E. coli sequence type 131

Dynamics of extended-spectrum cephalosporin resistance in pathogenic Escherichia coli isolated from diseased pigs in Quebec, Canada.

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Jahanbakhsh, Seyedehameneh; Smith, Matthew G; Kohan-Ghadr, Hamid-Reza; Letellier, Ann; Abraham, Sam; Trott, Darren J; Fairbrother, John Morris

2016-08-01

The aim of this study was to investigate the evolution with time of ceftiofur-resistant Escherichia coli clinical isolates from pigs in Québec, Canada, between 1997 and 2012 with respect to pathotypes, clones and antimicrobial resistance. Eighty-five ceftiofur-resistant E. coli isolates were obtained from the OIE (World Organisation for Animal Health) Reference Laboratory for Escherichia coli. The most prevalent pathovirotypes were enterotoxigenic E. coli (ETEC):F4 (40%), extraintestinal pathogenic E. coli (ExPEC) (16.5%) and Shiga toxin-producing E. coli (STEC):F18 (8.2%). Susceptibility testing to 15 antimicrobial agents revealed a high prevalence of resistance to 13 antimicrobials, with all isolates being multidrug-resistant. blaCMY-2 (96.5%) was the most frequently detected β-lactamase gene, followed by blaTEM (49.4%) and blaCTX-M (3.5%). Pulsed-field gel electrophoresis (PFGE) applied to 45 representative E. coli isolates revealed that resistance to ceftiofur is spread both horizontally and clonally. In addition, the emergence of extended-spectrum β-lactamase-producing E. coli isolates carrying blaCTX-M was observed in 2011 and 2012 in distinct clones. The most predominant plasmid incompatibility (Inc) groups were IncFIB, IncI1, IncA/C and IncFIC. Resistance to gentamicin, kanamycin and chloramphenicol as well as the frequency of blaTEM and IncA/C significantly decreased over the study period, whereas the frequency of IncI1 and multidrug resistance to seven antimicrobial categories significantly increased. These findings reveal that extended-spectrum cephalosporin-resistant porcine E. coli isolates in Québec belong to several different clones with diverse antimicrobial resistance patterns and plasmids. Furthermore, blaCMY-2 was the major β-lactamase gene in these isolates. From 2011, we report the emergence of blaCTX-M in distinct clones. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Prevalence of Class D Carbapenemases among Extended-Spectrum β-Lactamases Producing Escherichia coli Isolates from Educational Hospitals in Shahrekord

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Damavandi, Mohammad-Sadegh; Latif Pour, Mohammad

2016-01-01

Introduction Extended-spectrum β-lactamases (ESBLs) are a set of plasmid-borne, various and quickly evolving enzymes that are a main therapeutic issue now-a-days for inpatient and outpatient treatment. Aim The aim of this study was to determine multi-drug resistance (MDR) and ESBLs producing E. coli strains, prevalence of class D Carbapenemases among ESBLs producing Escherichia coli isolates from educational hospitals in Shahrekord, Iran. Materials and Methods Uropathogenic Escherichia coli strains were isolated from patients with Urinary Tract Infections (UTIs). The agar disc diffusion test was used to characterize the antimicrobial sensitivity of the E. coli isolates. The ESBL positive strains were identified by phenotypic double-disk synergy test, by third-generation cephalosporin in combination with or without clavulanic acid. Multiplex PCR was carried out for detection of the three families of OXA-type carbapenamases including OXA-23, OXA-24, and OXA-48 in E. coli strains. Results All bacterial isolates were susceptible to meropenem. Ninety isolates produced ESBL, 55 E. coli isolates from inpatients, and 35 isolates from outpatients, with a significant association (presistance in E. coli isolates. PMID:27462579

Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of the regulator AcrR from Escherichia coli

International Nuclear Information System (INIS)

Li, Ming; Qiu, Xi; Su, Chih-Chia; Long, Feng; Gu, Ruoyu; McDermott, Gerry; Yu, Edward W.

2006-01-01

The transcriptional regulator AcrR from Escherichia coli has been cloned, overexpressed, purified and crystallized and X-ray diffraction data have been collected to a resolution of 2.5 Å. This paper describes the cloning, expression, purification and preliminary X-ray data analysis of the AcrR regulatory protein. The Escherichia coli AcrR is a member of the TetR family of transcriptional regulators. It regulates the expression of the AcrAB multidrug transporter. Recombinant AcrR with a 6×His tag at the C-terminus was expressed in E. coli and purified by metal-affinity chromatography. The protein was crystallized using hanging-drop vapor diffusion. X-ray diffraction data were collected from cryocooled crystals at a synchrotron light source. The best crystal diffracted to 2.5 Å. The space group was determined to be P3 2 , with unit-cell parameters a = b = 46.61, c = 166.16 Å

MarA-like regulator of multidrug resistance in Yersinia pestis.

Science.gov (United States)

Udani, Rupa A; Levy, Stuart B

2006-09-01

MarA47(Yp) from Yersinia pestis, showing 47% identity to Escherichia coli MarA in its N terminus, caused resistance to antibiotics and to organic solvents when expressed in both E. coli and Y. pestis. Resistance was linked to increased expression of the AcrAB multidrug efflux pump. In four of five spontaneous multidrug-resistant mutants of Y. pestis independently selected by growth on tetracycline, the marA47(Yp) gene was overexpressed. The findings suggest that marA47(Yp) is a marA ortholog in Y. pestis.

Identification and Prevalence of Escherichia coli and Escherichia coli O157: H7 in Foods

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Ancuta Mihaela Rotar

2013-11-01

Full Text Available The objective of this study is to investigate the incidence of Escherichia coli in animal and non-animal foods, and mainly the incidence of the serotype O157: H7 producing verotoxin. The presence of common Escherichia coli and Escherichia coli O157: H7 in various foods (of animal and non animal origin was performed in Transylvania area. We analyzed a total of one hundred forty-one samples of minced meat, one hundred twenty-six samples of meat , twenty six samples of meat products, five samples of alcoholic beverages, three samples of seafood, one hundred samples of cheese from pasteurized milk, seventeen samples of butter, four samples of vegetables and one sample of milk powder, using the standard cultural method and Vidas Eco method for E. coli O157: H7 strains. E. coli was identified in 50 samples of minced meat, 55 samples of meat prepared, 4 samples of meat products, 2 samples of alcoholic beverages, 25 samples of cheese from pasteurized milk, 6 samples of butter and 1 sample of vegetables. In this study were not been identified any foods contaminated with the E. coli O157: H7 serotype. The results of this reasearch have demostrated that E. coli wich represents a hygienic indicator of recent food contamination, can be destroyed with heat treatment and hygienic handling of foods. Our country over the years has been among the few countries where the incidence of the E. coli O157: H7 serotype has been minimal.

Multidrug efflux systems in Escherichia coli and Enterobacter cloacae obtained from wholesome broiler carcasses Sistemas de efluxo multidroga em Escherichia coli e Enterobacter cloacae obtidas de carcaças de frangos sadios

Directory of Open Access Journals (Sweden)

Maria Aparecida S. Moreira

2009-06-01

Full Text Available Members of the Enterobacteriaceae family are present in the intestines of man and animals as commensals or are important disease causing agents. Bacteria bearing multidrug efflux systems (MDR are able to survive adverse ecological niches. Multiresistant Escherichia coli and Enterobacter cloacae isolates from wholesome broiler carcasses were investigated for the presence of MDR. Lowering of Minimal Inhibitory Concentration for antimicrobials in the presence of a proton-motive force (PMF uncoupler was tested as a potential display of the MDR phenotype. PCR amplification of the genes encoding AcrA and AcrB, components of a MDR system was performed. Diversity of each species was ascertained by Pulsed-Field Gel Electrophoresis (PFGE of DNA digested with endonuclease XbaI. For all the isolates, except E. coli 1 and E. cloacae 9, lowering of MIC or of the growth rate in the presence of antimicrobials was observed, indicating a PMF dependent resistance mechanism. Expected products of DNA amplification with acrAB derived primers was obtained with all E. coli strains and with two of the five E. cloacae strains. Dendrogram generated shows diverse pulsetypes, confirming the genetic diversity among the strains. An important issue and related public health is the fact that different models and mechanisms of antimicrobial resistance are present in a small number of non-pathogenic strains and isolated from the same origin. These may be sources of resistance genes to others microorganisms, among them, pathogenic strains.Os membros da família Enterobacteriaceae estão presentes no intestino do homem e dos animais como comensais ou agentes causadores de doença importantes. Bactérias multirresistentes podem possuir sistemas de efluxo multidrogas (MDR sendo capazes de sobreviver em nichos ecológicos adversos. Escherichia coli e Enterobacter cloacae, multirresistentes, isoladas de frangos sadios foram investigadas quanto à presença de MDR. A diminuição da

Escherichia Coli

Science.gov (United States)

Goodsell, David S.

2009-01-01

Diverse biological data may be used to create illustrations of molecules in their cellular context. I describe the scientific results that support a recent textbook illustration of an "Escherichia coli cell". The image magnifies a portion of the bacterium at one million times, showing the location and form of individual macromolecules. Results…

Gene encoding virulence markers among Escherichia coli isolates ...

African Journals Online (AJOL)

River water sources and diarrhoeic stools of residents in the Venda Region, Limpopo Province of South Africa were analysed for the prevalence of Escherichia coli (E. coli) and the presence of virulence genes among the isolates. A control group of 100 nondiarrhoeic stool samples was included. Escherichia coli was ...

escherichia coli serotypes confirmed in experimental mammary ...

African Journals Online (AJOL)

DJFLEX

VARIATIONS IN VIRULENCE OF THREE (3) ESCHERICHIA COLI. SEROTYPES CONFIRMED IN ... ows are susceptible to E. coli infection because. E. coli exist in the .... Coli infections in mice: A laboratory animal model for research in.

Antibacterial activity of herbal extracts against multi-drug resistant Escherichia coli recovered from retail chicken meat.

Science.gov (United States)

Shaheen, Arfat Yousaf; Sheikh, Ali Ahmad; Rabbani, Masood; Aslam, Asim; Bibi, Tasra; Liaqat, Fakhra; Muhammad, Javed; Rehmani, Shafqat Fatima

2015-07-01

Increasing incidence rate of multiple drug resistance in Escherichia coli (E. coli) due to extensive uses of antibiotics is a serious challenge to disease treatment. Contaminated retail chicken meat is one of the major sources of spread of multi drug resistant (MDR) E. coli. Current study has been conducted to study the prevalence of MDR E. coli in retail chicken meat samples from Lahore city of Pakistan and it was found that 73.86% of E. coli isolates have MDR pattern. In vitro evaluation of antibacterial activity of crude ethanolic extracts of six herbs against MDR E. coli phenotypes has revealed that clove and cinnamon have maximum zones of inhibition as compared to other herbal extracts. Mint and coriander gave the intermediate results while garlic and kalonji showed the least antibacterial activity against the MDR E. coli phenotypes using the agar well diffusion technique. Average Minimum Inhibitory Concentrations (MICs) for clove, mint, cinnamon, coriander, kalonji and garlic extracts were 1.15, 1.38, 0.5, 1.99, 2.41, 8.60 mg/mL respectively using the broth micro dilution method. The results obtained in present study were revealed that crude ethanol extracts of selected herbs have had significant antibacterial activity. Hence they can be used as promising alternatives of antimicrobials against MDR E. coli species and can be used for cooked food preservation.

Isolation of a conjugative F-like plasmid from a multidrug-resistant Escherichia coli strain CM6 using tandem shock wave-mediated transformation.

Science.gov (United States)

Soto-Alonso, G; Cruz-Medina, J A; Caballero-Pérez, J; Arvizu-Hernández, I; Ávalos-Esparza, L M; Cruz-Hernández, A; Romero-Gómez, S; Rodríguez, A L; Pastrana-Martínez, X; Fernández, F; Loske, A M; Campos-Guillén, J

2015-07-01

Genetic characterization of plasmids from bacterial strains provides insight about multidrug resistance. Ten wild type Escherichia coli (E. coli) strains isolated from cow fecal samples were characterized by their antibiotic resistance profile, plasmid patterns and three different identification methods. From one of the strains, a fertility factor-like plasmid was replicated using tandem shock wave-mediated transformation. Underwater shock waves with a positive pressure peak of up to approximately 40 MPa, followed by a pressure trough of approximately -19 MPa were generated using an experimental piezoelectric shock wave source. Three different shock wave energies and a fixed delay of 750 μs were used to study the relationship between energy and transformation efficiency (TE), as well as the influence of shock wave energy on the integrity of the plasmid. Our results showed that the mean shock wave-mediated TE and the integrity of the large plasmid (~70 kb) were reduced significantly at the energy levels tested. The sequencing analysis of the plasmid revealed a high identity to the pHK17a plasmid, including the replication system, which was similar to the plasmid incompatibility group FII. It also showed that it carried an extended spectrum beta-lactamase gene, ctx-m-14. Furthermore, diverse genes for the conjugative mechanism were identified. Our results may be helpful in improving methodologies for conjugative plasmid transfer and directly selecting the most interesting plasmids from environmental samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Chromatin architecture and gene expression in Escherichia coli

DEFF Research Database (Denmark)

Willenbrock, Hanni; Ussery, David

2004-01-01

Two recent genome-scale analyses underscore the importance of DNA topology and chromatin structure in regulating transcription in Escherichia coli.......Two recent genome-scale analyses underscore the importance of DNA topology and chromatin structure in regulating transcription in Escherichia coli....

Multidrug Resistance in Infants and Children

Directory of Open Access Journals (Sweden)

Gian Maria Pacifici

2018-02-01

Full Text Available Bacterial infections may cause disease and death. Infants and children are often subject to bacterial infections. Antimicrobials kill bacteria protecting the infected patients andreducing the risk of morbidity and mortality caused by bacteria. The antibiotics may lose their antibacterial activity when they become resistant to a bacteria. The resistance to different antibiotics in a bacteria is named multidrug-resistance. Gram-negative bacilli, especially Escherichia coli, Klebsiella, Enterobacter, Salmonella, Shigella, Pseudomonas, Streptococcus, and Haemophilus influenzae type b, may become resistant. Amikacin ampicillin, amoxicillin, amoxiclav, cefuroxime, cefotaxime, ceftazidime, cefoperazone tetracycline, chloramphenicol, ciprofloxacin, and gentamicin may cause bacterial-resistance. Resistance to bacteria for several pathogens makes complications in the treatment of infections caused by them. Salmonella strains may become resistant to ampicillin, cephalotin, ceftriaxone, gentamicin, amikacin, trimethoprim-sulfamethoxazole, chloramphenicol, and tetracycline. Shigella strains may become resistant to ampicillin, cotrimoxazole, chloramphenicol, and streptomycin. Multidrug-resistance of Streptococcus pneumoniae may be due to β-lactams, macrolides, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole. Multidrug-resistance of Pseudomonas aeruginosa may become resistant to β-lactams, chloramphenicol, trimethoprim-sulfamethoxazole, and tetracycline. The antibacterial activity against Haemophilus strains may occur with ampicillin, sulbactam-ampicillin, trimethoprim-sulfamethoxazole, gentamicin, chloramphenicol, and ciprofloxacin. Multidrug-resistance of the Klebsiella species may be due with ampicillin, cefotaxime, cefuroxime, co-amxilav, mezlocillin, chloramphenicol, gentamicin, and ceftazidime. Multidrug-resistance of Escherichia coli may be caused by ampicillin, cotrimoxazole, chloramphenicol, ceftriaxone, and ceftazidime. Vibrio

Enterohemorrhagic Escherichia coli (EHEC

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Abdullah Kilic

2011-08-01

Full Text Available Escherichia coli is a bacterium that is commonly found in the gut of humans and warm-blooded animals. Most strains of E. coli are harmless for human. E. coli O157:H7 is the most common member of a group of pathogenic E. coli strains known variously as enterohaemorrhagic, verocytotoxin-producing, or Shiga-toxin-producing organisms. EHEC bacterium is the major cause of haemorrhagic colitis and haemolytic uraemic syndrome. The reservoir of this pathogen appears to be mainly cattle and other ruminants such as camels. It is transmitted to humans primarily through consumption of contaminated foods. [TAF Prev Med Bull 2011; 10(4.000: 387-388

Comparative genomics of multidrug resistance-encoding IncA/C plasmids from commensal and pathogenic Escherichia coli from multiple animal sources.

Science.gov (United States)

Fernández-Alarcón, Claudia; Singer, Randall S; Johnson, Timothy J

2011-01-01

Incompatibility group A/C (IncA/C) plasmids have received recent attention for their broad host range and ability to confer resistance to multiple antimicrobial agents. Due to the potential spread of multidrug resistance (MDR) phenotypes from foodborne pathogens to human pathogens, the dissemination of these plasmids represents a public health risk. In this study, four animal-source IncA/C plasmids isolated from Escherichia coli were sequenced and analyzed, including isolates from commercial dairy cows, pigs and turkeys in the U.S. and Chile. These plasmids were initially selected because they either contained the floR and tetA genes encoding for florfenicol and tetracycline resistance, respectively, and/or the bla(CMY-2) gene encoding for extended spectrum β-lactamase resistance. Overall, sequence analysis revealed that each of the four plasmids retained a remarkably stable and conserved backbone sequence, with differences observed primarily within their accessory regions, which presumably have evolved via horizontal gene transfer events involving multiple modules. Comparison of these plasmids with other available IncA/C plasmid sequences further defined the core and accessory elements of these plasmids in E. coli and Salmonella. Our results suggest that the bla(CMY-2) plasmid lineage appears to have derived from an ancestral IncA/C plasmid type harboring floR-tetAR-strAB and Tn21-like accessory modules. Evidence is mounting that IncA/C plasmids are widespread among enteric bacteria of production animals and these emergent plasmids have flexibility in their acquisition of MDR-encoding modules, necessitating further study to understand the evolutionary mechanisms involved in their dissemination and stability in bacterial populations.

Comparative genomics of multidrug resistance-encoding IncA/C plasmids from commensal and pathogenic Escherichia coli from multiple animal sources.

Directory of Open Access Journals (Sweden)

Claudia Fernández-Alarcón

Full Text Available Incompatibility group A/C (IncA/C plasmids have received recent attention for their broad host range and ability to confer resistance to multiple antimicrobial agents. Due to the potential spread of multidrug resistance (MDR phenotypes from foodborne pathogens to human pathogens, the dissemination of these plasmids represents a public health risk. In this study, four animal-source IncA/C plasmids isolated from Escherichia coli were sequenced and analyzed, including isolates from commercial dairy cows, pigs and turkeys in the U.S. and Chile. These plasmids were initially selected because they either contained the floR and tetA genes encoding for florfenicol and tetracycline resistance, respectively, and/or the bla(CMY-2 gene encoding for extended spectrum β-lactamase resistance. Overall, sequence analysis revealed that each of the four plasmids retained a remarkably stable and conserved backbone sequence, with differences observed primarily within their accessory regions, which presumably have evolved via horizontal gene transfer events involving multiple modules. Comparison of these plasmids with other available IncA/C plasmid sequences further defined the core and accessory elements of these plasmids in E. coli and Salmonella. Our results suggest that the bla(CMY-2 plasmid lineage appears to have derived from an ancestral IncA/C plasmid type harboring floR-tetAR-strAB and Tn21-like accessory modules. Evidence is mounting that IncA/C plasmids are widespread among enteric bacteria of production animals and these emergent plasmids have flexibility in their acquisition of MDR-encoding modules, necessitating further study to understand the evolutionary mechanisms involved in their dissemination and stability in bacterial populations.

Emissions of Escherichia coli Carrying Extended-Spectrum β-Lactamase Resistance from Pig Farms to the Surrounding Environment

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Lili Gao

2015-04-01

Full Text Available The dissemination of extended-spectrum β-lactamase (ESBL-producing Escherichia coli (E. coli from food-producing animals to the surrounding environment has attracted much attention. To determine the emissions of ESBL-producing E. coli from pig farms to the surrounding environment, fecal and environmental samples from six pig farms were collected. In total, 119 ESBL-producing E. coli were isolated from feces, air samples, water, sludge and soil samples. Antibiotic susceptibility testing showed that the ESBL-producing isolates were resistant to multiple antibiotics and isolates of different origin within the same farm showed similar resistance phenotypes. Both CTX-M and TEM ESBL-encoding genes were detected in these isolates. CTX-M-14 and CTX-M-15 were the predominant ESBL genes identified. ESBL producers from feces and environmental samples within the same farm carried similar CTX-M types. The results indicated that the ESBL-producing E. coli carrying multidrug resistance could readily disseminate to the surrounding environment.

Cefoxitin resistance mediated by loss of a porin in clinical strains of Klebsiella pneumoniae and Escherichia coli

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Ananthan S

2005-01-01

Full Text Available PURPOSE: Porins are outer membrane protein (OMP that form water filled channels that permit the diffusion of small hydrophilic solutes like -lactam antibiotics across the outer membrane. Two major porins that facilitate diffusion of antimicrobials have been described in Klebsiella spp. and Escherichia coli. The present study was carried out to examine the role of porins among Extended Spectrum -Lactamase (ESBL and AmpC -Lactamase positive strains of Klebsiella spp. and E.coli. METHODS: Preparation of OMP from phenotypically characterized clinical isolates K.pneumoniae and E.coli and the separation of the proteins by sodium dodecyl sulfate - polyacrylamide gel electrophoresis were performed as per a previously described procedure. RESULTS: OMP analysis revealed that cefoxitin and ceftazidime resistance was mediated by loss of a porin Omp K35 in the isolates of K.pneumoniae and E.coli. CONCLUSIONS: Loss of porin mediated resistance mechanism against cefoxitin was observed among the multidrug resistant K.pneumoniae and E.coli.

Antimicrobial activity of peptidomimetics against multidrug-resistant Escherichia coli

DEFF Research Database (Denmark)

Jahnsen, Rasmus D; Frimodt-Møller, Niels; Franzyk, Henrik

2012-01-01

Novel remedies in the battle against multidrug-resistant bacterial strains are urgently needed, and one obvious approach involves antimicrobial peptides and mimics hereof. The impact of a- and ß-peptoid as well as ß(3)-amino acid modifications on the activity profile against ß-lactamase-producing...

Antibiotic resistant Salmonella and Escherichia coli isolated from ...

African Journals Online (AJOL)

Results: A hundred and four indigenous chicken rectal swabs were analysed, of which 67.3% were contaminated with Escherichia coli and 12.5% with Salmonella typhimurium. Seventy Escherichia coli isolates showed resistance phenotypes to one, two or more antibiotics. The most common antimicrobial resistance pattern ...

Identification, characterization and molecular epidemiology of Escherichia coli isolated from lamb and goat kids with diarrhoea

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Süheyla Türkyılmaz

2013-01-01

Full Text Available Neonatal diarrhoea is a serious health problem on commercial farms. Enterovirulent Escherichia coli is a significant aetiological agent of neonatal diarrhoea. In this work, identification and classification of E. coli isolates obtained from lambs and goat kids with diarrhoea were studied along with antibiotic resistance and clonal relationships of enterovirulent strains. A total of 107 E. coli strains isolated from animals on 43 farms were investigated. Specific virulence genes were determined by multiplex and uniplex polymerase chain reaction. Testing of antibiotic susceptibility was carried out by the Vitek II compact system. The relationship of E. coli isolates was determined by enterobacterial repetitive intergenic consensus polymerase chain reaction. A total of 39 (36.4% enterovirulent E. coli strains were identified and of this 19 (48.7% were shiga toxigenic, 12 (30.8% enterotoxigenic and 8 (20.5% enteropathogenic. Three isolates (7.7% were found to be positive for extended spectrum beta lactamase; 10 (25.6% isolates showed multi-drug resistance to antimicrobials. A total of 28 types were detected by enterobacterial repetitive intergenic consensus polymerase chain reaction. Twenty strains had distinct types while 5 types were common for 2 strains and 3 types were common for 3 strains. This is the first current determination of types, clonality and antibiotic resistance of enterovirulent E. coli isolated from small ruminants with diarrhoea. The results of this study showed that the rates of shiga toxigenic, enterotoxigenic and enteropathogenic isolates of E. coli are high in the western part of Turkey. Although these isolates were not clonal, presence of multidrug resistant isolates may cause public health problems.

Isolation and Characterization of phiLLS, a Novel Phage with Potential Biocontrol Agent against Multidrug-Resistant Escherichia coli

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Luis Amarillas

2017-07-01

Full Text Available Foodborne diseases are a serious and growing problem, and the incidence and prevalence of antimicrobial resistance among foodborne pathogens is reported to have increased. The emergence of antibiotic-resistant bacterial strains demands novel strategies to counteract this epidemic. In this regard, lytic bacteriophages have reemerged as an alternative for the control of pathogenic bacteria. However, the effective use of phages relies on appropriate biological and genomic characterization. In this study, we present the isolation and characterization of a novel bacteriophage named phiLLS, which has shown strong lytic activity against generic and multidrug-resistant Escherichia coli strains. Transmission electron microscopy of phiLLS morphology revealed that it belongs to the Siphoviridae family. Furthermore, this phage exhibited a relatively large burst size of 176 plaque-forming units per infected cell. Phage phiLLS significantly reduced the growth of E. coli under laboratory conditions. Analyses of restriction profiles showed the presence of submolar fragments, confirming that phiLLS is a pac-type phage. Phylogenetic analysis based on the amino acid sequence of large terminase subunits confirmed that this phage uses a headful packaging strategy to package their genome. Genomic sequencing and bioinformatic analysis showed that phiLLS is a novel bacteriophage that is most closely related to T5-like phages. In silico analysis indicated that the phiLLS genome consists of 107,263 bp (39.0 % GC content encoding 160 putative ORFs, 16 tRNAs, several potential promoters and transcriptional terminators. Genome analysis suggests that the phage phiLLS is strictly lytic without carrying genes associated with virulence factors and/or potential immunoreactive allergen proteins. The bacteriophage isolated in this study has shown promising results in the biocontrol of bacterial growth under in vitro conditions, suggesting that it may prove useful as an alternative

Effect of biocides on biofilms of some multidrug resistant clinical ...

African Journals Online (AJOL)

The ability of Escherichia coli and Klebsiella aerogenes to form biofilms was most affected. There was little inhibition of biofilm formation by the biocides on Staphylococcus aureus. This study has shown a relationship between biocide and multidrug resistance. Keywords: Biocides, Multi drug resistance, sodium hypochlorite, ...

Fimbrial adhesins from extraintestinal Escherichia coli

DEFF Research Database (Denmark)

Klemm, Per; Hancock, Viktoria; Schembri, Mark A.

2010-01-01

Extraintestinal pathogenic Escherichia coli (ExPEC) represent an important subclass of E. coli that cause a wide spectrum of diseases in human and animal hosts. Fimbriae are key virulence factors of ExPEC strains. These long surface located rod-shaped organelles mediate receptor-specific attachment...

Multidrug-Resistant Escherichia fergusonii: a Case of Acute Cystitis▿

Science.gov (United States)

Savini, Vincenzo; Catavitello, Chiara; Talia, Marzia; Manna, Assunta; Pompetti, Franca; Favaro, Marco; Fontana, Carla; Febbo, Fabio; Balbinot, Andrea; Di Berardino, Fabio; Di Bonaventura, Giovanni; Di Zacomo, Silvia; Esattore, Francesca; D'Antonio, Domenico

2008-01-01

We report a case in which Escherichia fergusonii, an emerging pathogen in various types of infections, was associated with cystitis in a 52-year-old woman. The offending strain was found to be multidrug resistant. Despite in vitro activity, beta-lactam treatment failed because of a lack of patient compliance with therapy. The work confirms the pathogenic potential of E. fergusonii. PMID:18256229

Complete Genome Sequence of Escherichia coli Strain WG5

DEFF Research Database (Denmark)

Imamovic, Lejla; Misiakou, Maria-Anna; van der Helm, Eric

2018-01-01

Escherichia coli strain WG5 is a widely used host for phage detection, including somatic coliphages employed as standard ISO method 10705-1 (2000). Here, we present the complete genome sequence of a commercial E. coli WG5 strain.......Escherichia coli strain WG5 is a widely used host for phage detection, including somatic coliphages employed as standard ISO method 10705-1 (2000). Here, we present the complete genome sequence of a commercial E. coli WG5 strain....

99mTechnetium labelled Escherichia coli

International Nuclear Information System (INIS)

Diniz, S.O.F.; Cardoso, V.N.; Resende, B.M.; Nunan, E.A.; Simal, C.J.R.

1999-01-01

Samples of a culture of unlabeled Escherichia coli were incubated with different concentrations of stannous chloride for various time periods. 99m Tc (26.0 MBq) was added to each preparation and the results showed a labelling yield of 98% for E. coli. Since the bacterial viability of 99m Tc-E. coli and E. coli did not show any statistical differences, these results demonstrate that labelling of E. coli with 99m Tc does not modify the bacterial viability, and the radiolabelled bacteria may be a good model to study bacterial translocation

Whole genome sequencing of ESBL-producing Escherichia coli isolated from patients, farm waste and canals in Thailand.

Science.gov (United States)

Runcharoen, Chakkaphan; Raven, Kathy E; Reuter, Sandra; Kallonen, Teemu; Paksanont, Suporn; Thammachote, Jeeranan; Anun, Suthatip; Blane, Beth; Parkhill, Julian; Peacock, Sharon J; Chantratita, Narisara

2017-09-06

Tackling multidrug-resistant Escherichia coli requires evidence from One Health studies that capture numerous potential reservoirs in circumscribed geographic areas. We conducted a survey of extended β-lactamase (ESBL)-producing E. coli isolated from patients, canals and livestock wastewater in eastern Thailand between 2014 and 2015, and analyzed isolates using whole genome sequencing. The bacterial collection of 149 isolates consisted of 84 isolates from a single hospital and 65 from the hospital sewer, canals and farm wastewater within a 20 km radius. E. coli ST131 predominated the clinical collection (28.6%), but was uncommon in the environment. Genome-based comparison of E. coli from infected patients and their immediate environment indicated low genetic similarity overall between the two, although three clinical-environmental isolate pairs differed by ≤ 5 single nucleotide polymorphisms. Thai E. coli isolates were dispersed throughout a phylogenetic tree containing a global E. coli collection. All Thai ESBL-positive E. coli isolates were multidrug resistant, including high rates of resistance to tobramycin (77.2%), gentamicin (77.2%), ciprofloxacin (67.8%) and trimethoprim (68.5%). ESBL was encoded by six different CTX-M elements and SHV-12. Three isolates from clinical samples (n = 2) or a hospital sewer (n = 1) were resistant to the carbapenem drugs (encoded by NDM-1, NDM-5 or GES-5), and three isolates (clinical (n = 1) and canal water (n = 2)) were resistant to colistin (encoded by mcr-1); no isolates were resistant to both carbapenems and colistin. Tackling ESBL-producing E. coli in this setting will be challenging based on widespread distribution, but the low prevalence of resistance to carbapenems and colistin suggests that efforts are now required to prevent these from becoming ubiquitous.

Comparative Genomics of Escherichia coli Isolated from Skin and Soft Tissue and Other Extraintestinal Infections.

Science.gov (United States)

Ranjan, Amit; Shaik, Sabiha; Nandanwar, Nishant; Hussain, Arif; Tiwari, Sumeet K; Semmler, Torsten; Jadhav, Savita; Wieler, Lothar H; Alam, Munirul; Colwell, Rita R; Ahmed, Niyaz

2017-08-15

Escherichia coli , an intestinal Gram-negative bacterium, has been shown to be associated with a variety of diseases in addition to intestinal infections, such as urinary tract infections (UTIs), meningitis in neonates, septicemia, skin and soft tissue infections (SSTIs), and colisepticemia. Thus, for nonintestinal infections, it is categorized as extraintestinal pathogenic E. coli (ExPEC). It is also an opportunistic pathogen, causing cross infections, notably as an agent of zoonotic diseases. However, comparative genomic data providing functional and genetic coordinates for ExPEC strains associated with these different types of infections have not proven conclusive. In the study reported here, ExPEC E. coli isolated from SSTIs was characterized, including virulence and drug resistance profiles, and compared with isolates from patients suffering either pyelonephritis or septicemia. Results revealed that the majority of the isolates belonged to two pathogenic phylogroups, B2 and D. Approximately 67% of the isolates were multidrug resistant (MDR), with 85% producing extended-spectrum beta-lactamase (ESBL) and 6% producing metallo-beta-lactamase (MBL). The bla CTX-M-15 genotype was observed in at least 70% of the E. coli isolates in each category, conferring resistance to an extended range of beta-lactam antibiotics. Whole-genome sequencing and comparative genomics of the ExPEC isolates revealed that two of the four isolates from SSTIs, NA633 and NA643, belong to pandemic sequence type ST131, whereas functional characteristics of three of the ExPEC pathotypes revealed that they had equal capabilities to form biofilm and were resistant to human serum. Overall, the isolates from a variety of ExPEC infections demonstrated similar resistomes and virulomes and did not display any disease-specific functional or genetic coordinates. IMPORTANCE Infections caused by extraintestinal pathogenic E. coli (ExPEC) are of global concern as they result in significant costs to

Response of Escherichia coli to Prolonged Berberine Exposure.

Science.gov (United States)

Budeyri Gokgoz, Nilay; Avci, Fatma Gizem; Yoneten, Kubra Karaosmanoglu; Alaybeyoglu, Begum; Ozkirimli, Elif; Sayar, Nihat Alpagu; Kazan, Dilek; Sariyar Akbulut, Berna

2017-07-01

Berberine is a plant-derived alkaloid possessing antimicrobial activity; unfortunately, its efflux through multidrug resistance pumps reduces its efficacy. Cellular life span of Escherichia coli is generally shorter with prolonged berberine exposure; nevertheless, about 30% of the cells still remain robust following this treatment. To elucidate its mechanism of action and to identify proteins that could be involved in development of antimicrobial resistance, protein profiles of E. coli cells treated with berberine for 4.5 and 8 hours were compared with control cells. A total of 42 proteins were differentially expressed in cells treated with berberine for 8 hours when compared to control cells. In both 4.5 and 8 hours of berberine-treated cells, carbohydrate and peptide uptake regimens remained unchanged, although amino acid maintenance regimen switched from transport to synthesis. Defect in cell division persisted and this condition was confirmed by images obtained from scanning electron microscopy. Universal stress proteins were not involved in stress response. The significant increase in the abundance of elongation factors could suggest the involvement of these proteins in protection by exhibiting chaperone activities. Furthermore, the involvement of the outer membrane protein OmpW could receive special attention as a protein involved in response to antimicrobial agents, since the expression of only this porin protein was upregulated after 8 hours of exposure.

Antimicrobial resistance, virulence, and phylogenetic characteristics of Escherichia coli isolates from clinically healthy swine.

Science.gov (United States)

Lay, Khin Khin; Koowattananukul, Chailai; Chansong, Nisit; Chuanchuen, Rungtip

2012-11-01

A total of 344 commensal Escherichia coli isolates from clinically healthy pigs were examined for antimicrobial resistance phenotypes, class 1 integrons, resistance genes, virulence gene profile, and phylogenetic groups. The majority of E. coli isolates were resistant to tetracycline (96.2%) and ampicillin (91.6%). Up to 98% were multidrug resistant. Seventy-three percent of the isolates carried class 1 integrons. Inserted-gene cassette arrays in variable regions included incomplete sat, aadA22, aadA1, dfrA12-aadA2, and sat-psp-aadA2, of which the aadA2 gene cassette was most prevalent (42.9%). Horizontal transfer was detected in eight E. coli isolates carrying class 1 integrons with dfrA12-aadA2 gene cassette array. Sixteen resistance genes were identified among the E. coli isolates with corresponding resistance phenotype. Ten virulence genes (including elt, estA, estB, astA, faeG, fasA, fedA, eaeA, paa, and sepA) were detected, of which fasA was most commonly found (98.3%). Most of the E. coli isolates belonged to phylogenetic group B1. Significantly positive associations were observed between some virulence genes and some resistance phenotypes and genotypes (p antimicrobial resistance-encoding genes and virulence determinants.

Asymptomatic bacteriuria Escherichia coli strains

DEFF Research Database (Denmark)

Hancock, Viktoria; Nielsen, E.M.; Klemm, Per

2006-01-01

Urinary tract infections (UTIs) affect millions of people each year. Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU) in humans. Persons affected by ABU may carry a particular E. coli strain for extended periods of time without any symptoms. In contrast...... to uropathogenic E. coli (UPEC) that cause symptomatic UTI, very little is known about the mechanisms by which these strains colonize the urinary tract. Here, we have investigated the growth characteristics in human urine as well as adhesin repertoire of nine ABU strains; the ability of ABU strains to compete...

Prevalence and Antibiotic Susceptibility Patterns of Extended-Spectrum ß-Lactamase and Metallo-ß-Lactamase-Producing Uropathogenic Escherichia coli Isolates.

Science.gov (United States)

Ghadiri, Hamed; Vaez, Hamid; Razavi-Azarkhiavi, Kamal; Rezaee, Ramin; Haji-Noormohammadi, Mehdi; Rahimi, Ali Asghar; Vaez, Vahid; Kalantar, Enayatollah

2014-01-01

Healthcare professionals worldwide have expressed concern over infections by extended-spectrum ß-lactamase (ESBL) and metallo-ß-lactamase (MBL)-producing bacteria. We evaluated the prevalence of ESBL- and MBL-producing Escherichia coli (E. coli) isolated from community-acquired urinary tract infections (UTIs) and their antibiotic-resistance profiles at 3 private laboratories in Tehran, Iran. E. coli isolates were mostly susceptible to meropenem (90.4%) and imipenem (90.0%), followed by amikacin (89.0%) and gentamicin (84.7%). Moreover, we detected that, of the E. coli isolates, 67 (22.3%) were ESBL producers and 21 (7.0%) of E. coli isolates were MBL positive via the imipenem-ethylenediaminetetraacetic acid (EDTA) combined disc test. This report is the first, to our knowledge, on the prevalence of MBL-producing uropathogenic E. coli (UPEC) strains in Iran. The antibiotic resistance of E. coli isolates revealed that 122 (40.7%) were multidrug resistant. The high number of antibiotic-resistant and ß-lactamase-producing UPEC strains necessitates further attention and consideration, particularly MBL-producing strains. Copyright© by the American Society for Clinical Pathology (ASCP).

Colonization of Enteroaggregative Escherichia coli and Shiga toxin-producing Escherichia coli in chickens and humans in southern Vietnam

NARCIS (Netherlands)

Trung, Nguyen Vinh; Nhung, Hoang Ngoc; Carrique-Mas, Juan J.; Mai, Ho Huynh; Tuyen, Ha Thanh; Campbell, James; Nhung, Nguyen Thi; van Minh, Pham; Wagenaar, Jaap A.; Mai, Nguyen Thi Nhu; Hieu, Thai Quoc; Schultsz, Constance; Hoa, Ngo Thi

2016-01-01

Enteroaggregative (EAEC) and Shiga-toxin producing Escherichia coli (STEC) are a major cause of diarrhea worldwide. E. coli carrying both virulence factors characteristic for EAEC and STEC and producing extended-spectrum beta-lactamase caused severe and protracted disease during an outbreak of E.

Antimicrobial susceptibility of Escherichia coli isolated from feces of wild cranes migrating to Kagoshima, Japan.

Science.gov (United States)

Kitadai, Noriyuki; Obi, Takeshi; Yamashita, Shogo; Murase, Toshiyuki; Takase, Kozo

2012-03-01

Susceptibility to 13 antimicrobial agents was examined for 138 Escherichia coli isolates obtained from 192 fecal samples of wild cranes that migrated for wintering to the Izumi plain, Kagoshima prefecture in Japan. The numbers of isolates that were resistant to the antimicrobials used in this study are as follows: oxytetracycline (OTC), 22 isolates; minocycline, 7 isolates; ampicillin (ABPC), 4 isolates; nalidixic acid, 4 isolates; enrofloxacin, 2 isolates; kanamycin, one isolate. Multidrug resistant isolates exhibiting 2-4 drug resistances were obtained. All of the OTC-resistant isolates carried either the tet (A) or tet(B) gene. The bla(TEM) gene was found in all of the ABPC-resistant isolates.

[Virulence markers of Escherichia coli O1 strains].

Science.gov (United States)

Makarova, M A; Kaftyreva, L A; Grigor'eva, N S; Kicha, E V; Lipatova, L A

2011-01-01

To detect virulence genes in clinical isolates of Escherichia coli O1 using polymerase chain reaction (PCR). One hundred and twenty strains of E.coli O1 strains isolated from faeces of patients with acute diarrhea (n = 45) and healthy persons (n = 75) were studied. PCR with primers for rfb and fliC genes, which control synthesis of O- and H- antigens respectively, was used. Fourteen virulence genes (pap, aaf, sfa, afa, eaeA, bfpA, ial, hly, cnf, stx1, stx2, lt, st, and aer) were detected by PCR primers. K1-antigen was determined by Pastorex Meningo B/E. coli O1 kit (Bio-Rad). rfb gene controlling O-antigen synthesis in serogroup O1 as well as fliC gene controlling synthesis of H7 and K1 antigens were detected in all strains. Thus all E. coli strains had antigenic structure O1:K1 :H-:F7. Virulence genes aafl, sfa, afa, eaeA, bfpA, ial, hly, cnf, stx1, stx2, lt, and st were not detected. All strains owned pap and aer genes regardless of the presence of acute diarrhea symptoms. It was shown that E. coli O1:KI:H-:F7 strains do not have virulence genes which are characteristic for diarrhea-causing Escherichia. In accordance with the presence of pap and aer genes they could be attributed to uropathogenic Escherichia (UPEC) or avian-pathogenic Escherichia (APEC). It is necessary to detect virulence factors in order to determine E. coli as a cause of intestinal infection.

Characterization of Escherichia coli Phylogenetic Groups ...

African Journals Online (AJOL)

Background: Escherichia coli strains mainly fall into four phylogenetic groups (A, B1, B2, and D) and that virulent extra‑intestinal strains mainly belong to groups B2 and D. Aim: The aim was to determine the association between phylogenetic groups of E. coli causing extraintestinal infections (ExPEC) regarding the site of ...

Transport of Escherichia coli phage through saturated porous media considering managed aquifer recharge.

Science.gov (United States)

Zhang, Wenjing; Li, Shuo; Wang, Shuang; Lei, Liancheng; Yu, Xipeng; Ma, Tianyi

2018-03-01

Virus is one of the most potentially harmful microorganisms in groundwater. In this paper, the effects of hydrodynamic and hydrogeochemical conditions on the transportation of the colloidal virus considering managed aquifer recharge were systematically investigated. Escherichia coli phage, vB_EcoM-ep3, has a broad host range and was able to lyse pathogenic Escherichia coli. Bacteriophage with low risk to infect human has been found extensively in the groundwater environment, so it is considered as a representative model of groundwater viruses. Laboratory studies were carried out to analyze the transport of the Escherichia coli phage under varying conditions of pH, ionic strength, cation valence, flow rate, porous media, and phosphate buffer concentration. The results indicated that decreasing the pH will increase the adsorption of Escherichia coli phage. Increasing the ionic strength, either Na + or Ca 2+ , will form negative condition for the migration of Escherichia coli phage. A comparison of different cation valence tests indicated that changes in transport and deposition were more pronounced with divalent Ca 2+ than monovalent Na + . As the flow rate increases, the release of Escherichia coli phage increases and the retention of Escherichia coli phage in the aquifer medium reduces. Changes in porous media had a significant effect on Escherichia coli phage migration. With increase of phosphate buffer concentration, the suspension stability and migration ability of Escherichia coli phage are both increased. Based on laboratory-scale column experiments, a one-dimensional transport model was established to quantitatively describe the virus transport in saturated porous medium.

ELECTROPHORETIC MOBILITIES OF ESCHERICHIA COLI 0157:H7 AND WILD-TYPE ESCHERICHIA COLI STRAINS

Science.gov (United States)

The electrophoretic mobility (EPM) of a number of human-virulent and "wild-type" Escherichia coli strains in phosphate buffered water was measured. The impact of pH, ionic strength, cation type (valence) and concentration, and bacterial strain on the EPM was investigated. Resul...

Escherichia coli survival in waters: Temperature dependence

Science.gov (United States)

Knowing the survival rates of water-borne Escherichia coli is important in evaluating microbial contamination and making appropriate management decisions. E. coli survival rates are dependent on temperature, a dependency that is routinely expressed using an analogue of the Q10 mo...

Genomic Analysis of Multidrug-Resistant Escherichia coli from North Carolina Community Hospitals: Ongoing Circulation of CTX-M-Producing ST131-H30Rx and ST131-H30R1 Strains.

Science.gov (United States)

Kanamori, Hajime; Parobek, Christian M; Juliano, Jonathan J; Johnson, James R; Johnston, Brian D; Johnson, Timothy J; Weber, David J; Rutala, William A; Anderson, Deverick J

2017-08-01

Escherichia coli sequence type 131 (ST131) predominates globally among multidrug-resistant (MDR) E. coli strains. We used whole-genome sequencing (WGS) to investigate 63 MDR E. coli isolates from 7 North Carolina community hospitals (2010 to 2015). Of these, 39 (62%) represented ST131, including 37 (95%) from the ST131- H 30R subclone: 10 (27%) from its H 30R1 subset and 27 (69%) from its H 30Rx subset. ST131 core genomes differed by a median of 15 (range, 0 to 490) single-nucleotide variants (SNVs) overall versus only 7 within H 30R1 (range, 3 to 12 SNVs) and 11 within H 30Rx (range, 0 to 21). The four isolates with identical core genomes were all H 30Rx. Epidemiological and clinical characteristics did not vary significantly by strain type, but many patients with MDR E. coli or H 30Rx infection were critically ill and had poor outcomes. H 30Rx isolates characteristically exhibited fluoroquinolone resistance and CTX-M-15 production, had a high prevalence of trimethoprim-sulfamethoxazole resistance (89%), sul1 (89%), and dfrA17 (85%), and were enriched for specific virulence traits, and all qualified as extraintestinal pathogenic E. coli The high overall prevalence of CTX-M-15 appeared to be possibly attributable to its association with the ST131- H 30Rx subclone and IncF[F2:A1:B-] plasmids. Some phylogenetically clustered non-ST131 MDR E. coli isolates also had distinctive serotypes/ fimH types, fluoroquinolone mutations, CTX-M variants, and IncF types. Thus, WGS analysis of our community hospital source MDR E. coli isolates suggested ongoing circulation and differentiation of E. coli ST131 subclones, with clonal segregation of CTX-M variants, other resistance genes, Inc-type plasmids, and virulence genes. Copyright © 2017 American Society for Microbiology.

Synergistic effect of eugenol with Colistin against clinical isolated Colistin-resistant Escherichia coli strains

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Yi-ming Wang

2018-01-01

Full Text Available Abstract Background Bacterial infections have become more challenging to treat due to the emergence of multidrug-resistant pathogenic bacteria. Combined antibiotics prove to be a relatively effective method to control such resistant strains. This study aim to investigate synergistic activity of eugenol combined with colistin against a collection of clinical isolated Escherichia coli (E.coli strains, and to evaluate potential interaction. Methods Antimicrobial susceptibility, minimum inhibitory concentration (MIC and fractional inhibitory concentration index (FICI of the bacteria were determined by disk diffusion assay, broth microdilution method and checkerboard assay, respectively. The mcr-1 mRNA expression was measured by Real-time PCR. To predict possible interactions between eugenol and MCR-1, molecular docking assay was taken. Results For total fourteen strains including eight colistin-resistant strains, eugenol was determined with MIC values of 4 to 8 μg/mL. Checkerboard dilution test suggested that eugenol exhibited synergistic activity when combined with colistin (FICI ranging from 0.375 to 0.625. Comparison analysis of Real-time PCR showed that synergy could significantly down-regulate expression of mcr-1 gene. A metal ion coordination bond with catalytic zinc atom and a hydrogen bond with crucial amino acid residue Ser284 of MCR-1 were observed after molecular docking, indicating antibacterial activity and direct molecular interactions of eugenol with MCR-1 protein. Conclusions Our results demonstrated that eugenol exhibited synergistic effect with colistin and enhanced its antimicrobial activity. This might further contribute to the antibacterial actions against colistin-resistant E.coli strains. Graphical abstract Synergistic effect of eugenol with colistin against colistin-resistant Escherichia coli isolates.

Virulence, resistance, and genetic relatedness of Escherichia coli and Klebsiella sp. isolated from mule foals

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V.C. Carneiro

Full Text Available ABSTRACT Respiratory diseases are common in young horses but little is known about such infections in mule foals. This study aimed to characterize Escherichia coli and Klebsiella sp. isolated from tracheal wash (TW and fecal samples (FS of mule foals, with or without cytological evidence of respiratory disease. Strains were analyzed against 13 antimicrobials, for presence of Extended spectrum beta-lactamase (ESBL, and virulence genes. Phylogrouping and Randomic (RAPD-PCR profiles were used to evaluate their genetic relatedness. E. coli strains from TW and FS showed greatest resistance to tetracycline, while Klebsiella strains were mainly resistant to ampicillin; multidrug resistance and ESBL production were also detected. The blaCTX gene prevailed among the E. coli isolates, while the blaSHV gene was more frequently found in K. pneumoniae. The fimH gene was detected in most of the isolates and multiple virulence factors were identified in three E. coli isolates. Most of the E. coli isolates belonged to the B1 phylogroup, but B2 strains displayed more virulence genes. The RAPD assay revealed genetic diversity among strains and was able to distinguish FS isolates from TW isolates. Knowledge of the bacteria associated with the respiratory tract of mule foals is important in the treatment of sick animals.

Chromosomal features of Escherichia coli serotype O2:K2, an avian pathogenic E. coli

DEFF Research Database (Denmark)

Jørgensen, Steffen L; Kudirkiene, Egle; Li, Lili

2017-01-01

Escherichia coli causing infection outside the gastrointestinal system are referred to as extra-intestinal pathogenic E. coli. Avian pathogenic E. coli is a subgroup of extra-intestinal pathogenic E. coli and infections due to avian pathogenic E. coli have major impact on poultry production econo...

Comparison of 61 Sequenced Escherichia coli Genomes

DEFF Research Database (Denmark)

Lukjancenko, Oksana; Wassenaar, T. M.; Ussery, David

2010-01-01

Escherichia coli is an important component of the biosphere and is an ideal model for studies of processes involved in bacterial genome evolution. Sixty-one publically available E. coli and Shigella spp. sequenced genomes are compared, using basic methods to produce phylogenetic and proteomics...

lactamase in clinical isolates of Escherichia coli

African Journals Online (AJOL)

Jane

2011-08-22

Aug 22, 2011 ... The beta lactamase enzyme producing E. coli, resistant to β-lactam antibiotics, created many problems ... Key words: Escherichia coli, β-lactamase enzymes, TEM-type extended spectrum ... difficulties in treatment using antibiotics that are currently ... and chloramphenicol (30 µg) (Mast Diagnostics Ltd., UK).

Escherichia coli and urinary tract infections: the role of poultry-meat.

Science.gov (United States)

Manges, A R

2016-02-01

Extraintestinal pathogenic Escherichia coli (ExPEC) is the most common cause of community-acquired and hospital-acquired extraintestinal infections. The hypothesis that human ExPEC may have a food animal reservoir has been a topic of investigation by multiple groups around the world. Experimental studies showing the shared pathogenic potential of human ExPEC and avian pathogenic E. coli suggest that these extraintestinal E. coli may be derived from the same bacterial lineages or share common evolutionary roots. The consistent observation of specific human ExPEC lineages in poultry or poultry products, and rarely in other meat commodities, supports the hypothesis that there may be a poultry reservoir for human ExPEC. The time lag between human ExPEC acquisition (in the intestine) and infection is the fundamental challenge facing studies attempting to attribute ExPEC transmission to poultry or other environmental sources. Even whole genome sequencing efforts to address attribution will struggle with defining meaningful genetic relationships outside of a discrete food-borne outbreak setting. However, if even a fraction of all human ExPEC infections, especially antimicrobial-resistant ExPEC infections, is attributable to the introduction of multidrug-resistant ExPEC lineages through contaminated food product(s), the relevance to public health, food animal production and food safety will be significant. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Characterization of Multidrug Resistant Extended-Spectrum Beta-Lactamase-Producing Escherichia coli among Uropathogens of Pediatrics in North of Iran

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Mohammad Sadegh Rezai

2015-01-01

Full Text Available Escherichia coli remains as one of the most important bacteria causing infections in pediatrics and producing extended-spectrum beta-lactamases (ESBLs making them resistant to beta-lactam antibiotics. In this study we aimed to genotype ESBL-producing E. coli isolates from pediatric patients for ESBL genes and determine their association with antimicrobial resistance. One hundred of the E. coli isolates were initially considered ESBL producing based on their MIC results. These isolates were then tested by polymerase chain reaction (PCR for the presence or absence of CTX, TEM, SHV, GES, and VEB beta-lactamase genes. About 30.5% of isolated E. coli was ESBL-producing strain. The TEM gene was the most prevalent (49% followed by SHV (44%, CTX (28%, VEB (8%, and GES (0% genes. The ESBL-producing E. coli isolates were susceptible to carbapenems (66% and amikacin (58% and showed high resistance to cefixime (99%, colistin (82%, and ciprofloxacin (76%. In conclusion, carbapenems were the most effective antibiotics against ESBl-producing E. coli in urinary tract infection in North of Iran. The most prevalent gene is the TEM-type, but the other resistant genes and their antimicrobial resistance are on the rise.

Characterization of Escherichia coli Phylogenetic Groups ...

African Journals Online (AJOL)

tract infection (UTI), bacteremia, pneumonia, soft-tissue infection, and ... Keywords: Drug resistance, Escherichia coli, Extraintestinal infections, Polymerase chain reaction, .... gynecology, 12 from orthopedics and 5 from pediatrics units.

Plasmid-Mediated Quinolone Resistance Genes in Escherichia coli ...

African Journals Online (AJOL)

Erah

PMQR) genes and the prevalence of extended spectrum β-lactamase (ESBL) types in Escherichia coli clinical isolates. Methods: Sixty-one ESBL-producing urinary E. coli isolates were studied. An antibiotic susceptibility test was performed ...

The Relationship Between Class I and II Integrons and Antibiotic Resistance Among Escherichia coli Isolates From Urinary Tract Infections

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Farshad Nojoomi

2018-05-01

Full Text Available Objective: the aim of this study was determination of antibiotic resistance profile, investigation of class I and II integrons among Escherichia coli (E. coli isolates from urinary tract infections. This study was conducted for the investigation of the prevalence of class I and II Integrons among E. coli Isolates from urinary tract infections. Materials and Methods: A total of 100 E. coli clinical isolates were collected from urinary tract infections in Borujerd city, Iran, from… to …. All the isolates were identified with standard laboratory procedures as described everywhere. The antibiotic susceptibility profile was conducted against adopted antibiotic disks following CLSI 2016 guidelines. All the isolates were enrolled in the PCR technique for the presence of class I and II integrons. Results: the highest resistance was against amoxicillin (72%, ciprofloxacin (69%, nalidixic acid (55% and tetracycline (51%. The prevalence of class I and II integrons was 31% and 21%, respectively. A significant relation was observed between resistance to trimethoprim-sulfamethoxazole (p<0.001, nalidixic acid (p<0.01 and tetracycline (p<0.005 with the presence of class I integron. The rate of class I integron in the E. coli isolates was high, possibly playing a role in the spread of multidrug resistant isolates. Conclusion: considering the significant relation observed between the presence of class I integron among multidrug-resistant isolates, establishment implementation of proper procedures to control and suitable treatment strategies in hospitals seems essential for the prevention of more spread of these isolates.

Antimicrobial resistance among commensal Escherichia coli from ...

African Journals Online (AJOL)

Commensal bacteria contribute to the distribution and persistence of antimicrobial resistance in the environment. This study monitored antimicrobial resistance in commensal Escherichia coli from the faeces of on-farm and slaughter cattle and beef. A total of 342 (89.5%) E. coli isolates were obtained from 382 samples.

Antimicrobial resistance among commensal Escherichia coli from ...

African Journals Online (AJOL)

user1

2012-07-19

Jul 19, 2012 ... Commensal bacteria contribute to the distribution and persistence of antimicrobial resistance in the environment. This study monitored antimicrobial resistance in commensal Escherichia coli from the faeces of on-farm and slaughter cattle and beef. A total of 342 (89.5%) E. coli isolates were obtained.

Fecal Microbiota Transfer for Multidrug-Resistant Gram-Negatives: A Clinical Success Combined With Microbiological Failure.

Science.gov (United States)

Stalenhoef, Janneke E; Terveer, Elisabeth M; Knetsch, Cornelis W; Van't Hof, Peter J; Vlasveld, Imro N; Keller, Josbert J; Visser, Leo G; Kuijper, Eduard J

2017-01-01

Combined fecal microbiota transfer and antibiotic treatment prevented recurrences of urinary tract infections with multidrug-resistant (MDR) Pseudomonas aeruginosa , but it failed to eradicate intestinal colonization with MDR Escherichia coli . Based on microbiota analysis, failure was not associated with distinct diminished microbiota diversity.

Strategies for Protein Overproduction in Escherichia coli.

Science.gov (United States)

Mott, John E.

1984-01-01

Examines heterologous expression in Escherichia coli and the role of regulatory sequences which control gene expression at transcription resulting in abundant production of messenger RNA and regulatory sequences in mRNA which promote efficient translation. Also examines the role of E. coli cells in stabilizing mRNA and protein that is…

Cancerous patients and outbreak of Escherichia coli: an important issue in oncology

OpenAIRE

Joob, Beuy; Wiwanitkit, Viroj

2014-01-01

The widespread of the Escherichia coli outbreak in Europe becomes an important public concern at global level. The infection can be serious and might result in death. The retrospective literature review on this specific topic is performed. In this specific brief article, the author presented and discussed on the problem of Escherichia coli infection in the cancerous patients. This is an actual important issue in medical oncology for the scenario of Escherichia coli epidemic.

Infectious endocarditis caused by Escherichia coli

DEFF Research Database (Denmark)

Lauridsen, Trine Kiilerich; Arpi, Magnus; Fritz-Hansen, Thomas

2011-01-01

Although Escherichia coli is among the most common causes of Gram-negative bacteraemia, infectious endocarditis (IE) due to this pathogen is rare. A 67-y-old male without a previous medical history presented with a new mitral regurgitation murmur and persisting E. coli bacteraemia in spite of broad......-spectrum intravenous antibiotics. Transthoracic and transoesophageal echocardiography revealed a severe mitral endocarditis. E. coli DNA was identified from the mitral valve and the vegetation, and no other pathogen was found. The case was further complicated by spondylodiscitis and bilateral endophthalmitis. Extra...

Translational coupling in Escherichia coli of a heterologous Bacillus subtilis-Escherichia coli gene fusion.

OpenAIRE

Zaghloul, T I; Doi, R H

1986-01-01

The efficient expression in Escherichia coli of the Tn9-derived chloramphenicol acetyltransferase (EC 2.3.1.28) gene fused distal to the promoter and N terminus of the Bacillus subtilis aprA gene was dependent on the initiation of translation from the ribosome-binding site in the aprA gene.

ANTIMICROBIAL DRUG RESISTANCE IN STRAINS OF Escherichia coli ISOLATED FROM FOOD SOURCES

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Mohammed Uddin Rasheed

2014-07-01

Full Text Available A variety of foods and environmental sources harbor bacteria that are resistant to one or more antimicrobial drugs used in medicine and agriculture. Antibiotic resistance in Escherichia coli is of particular concern because it is the most common Gram-negative pathogen in humans. Hence this study was conducted to determine the antibiotic sensitivity pattern of E. coli isolated from different types of food items collected randomly from twelve localities of Hyderabad, India. A total of 150 samples comprising; vegetable salad, raw egg-surface, raw chicken, unpasteurized milk, and raw meat were processed microbiologically to isolate E. coli and to study their antibiotic susceptibility pattern by the Kirby-Bauer method. The highest percentages of drug resistance in isolates of E. coli were detected from raw chicken (23.3% followed by vegetable salad (20%, raw meat (13.3%, raw egg-surface (10% and unpasteurized milk (6.7%. The overall incidence of drug resistant E. coli was 14.7%. A total of six (4% Extended Spectrum β-Lactamase (ESBL producers were detected, two each from vegetable salads and raw chicken, and one each from raw egg-surface and raw meat. Multidrug resistant strains of E. coli are a matter of concern as resistance genes are easily transferable to other strains. Pathogen cycling through food is very common and might pose a potential health risk to the consumer. Therefore, in order to avoid this, good hygienic practices are necessary in the abattoirs to prevent contamination of cattle and poultry products with intestinal content as well as forbidding the use of untreated sewage in irrigating vegetables.

The Escherichia coli transcriptome linked to growth fitness

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Bei-Wen Ying

2016-03-01

Full Text Available A series of Escherichia coli strains with varied genomic sequences were subjected to high-density microarray analyses to elucidate the fitness-correlated transcriptomes. Fitness, which is commonly evaluated by the growth rate during the exponential phase, is not only determined by the genome but is also linked to growth conditions, e.g., temperature. We previously reported genetic and environmental contributions to E. coli transcriptomes and evolutionary transcriptome changes in thermal adaptation. Here, we describe experimental details on how to prepare microarray samples that truly represent the growth fitness of the E. coli cells. A step-by-step record of sample preparation procedures that correspond to growing cells and transcriptome data sets that are deposited at the GEO database (GSE33212, GSE52770, GSE61739 are also provided for reference. Keywords: Transcriptome, Growth fitness, Escherichia coli, Microarray

Antibiotic resistance of Verotoxigenic Escherichia coli isolated from vegetables

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mojtaba boniadian

2017-01-01

Full Text Available Introduction: Human gastrointestinal disease caused by verotoxigenic Escherichia coli has been diagnosed for recent decades. Escherichia coli O157:H7 is the most important serotype of verotoxigenic Escherichia coli that cause hemolytic uremic syndrome and hemorrhagic colitis in humans. This study was conducted to determine the occurrence of verotoxigenic E. coli and antibiotic resistance of the isolates from vegetables. Materials and methods: A total of 500 fresh vegetable samples were collected randomly from retail shops in Shahrekord, Iran. E. coli was isolated and identified using bacteriological and biochemical tests. PCR method was used to identify the rbfE, stx1, stx2 and eae genes. Also, antibiotic resistance of the isolates was determined by disk diffusion method. Results: The results represented that among 25 isolates possess virulence genes, 40, 12 and 4% of the isolates contained eaeA, STx2, and both genes, respectively. But none of them contained H7, STx1, and rfbE genes. The antibiotic resistance pattern demonstrated that the isolates were highly resistant to Gentamycin and cefotoxime. Discussion and conclusion: The results of this study showed that the presence of verotoxigenic E.coli in vegetables; and high resistance of the isolates to antibiotics could be hazardous for public health.

The propagation of Escherichia Coli and of conservative tracers. A comparison

International Nuclear Information System (INIS)

Alexander, I.; Seiler, K.P.

1982-01-01

The propagation of Escherichia Coli (ATCC 11229, Gelsenkirchen) is compared with that of conservative tracers in groundwater. The experiments were performed with injection quantities of 10 7 , 10 8 , 10 10 and 10 11 of Escherichia Coli. Both, bacteria and conservative tracers pass their maximum at the same instant in the observation gauges. With injection quantities of more than 10 8 , the propagation of the Escherichia Coli sets in at the same time as it begins with the dyes. When the quantities range below 10 8 , the propagation begins after that of conservative tracers, because Coli bacteria were measured with a lower degree of detecting sensitivity than the tracers. With Coli injection quantities ranging above 10 10 , an increased filtering of these bacteria can be observed. Coli bacteria propagate more laterally than conservative tracers, however it could not be proved that this lateral propagation depends on the bacteria concentration. (orig.) [de

76 FR 20542 - Escherichia coli

Science.gov (United States)

2011-04-13

... beef, Escherichia coli and coliphages were found in chicken, fresh pork, fresh oyster, fresh mushrooms, lettuce, chicken pot pie, biscuit dough, deli loaf, deli roasted turkey, and package roasted chicken... surfaces, and in foods such as ground beef, pork sausage, chicken, oysters, cheese, fresh mushrooms, and...

Multiplex polymerase chain reaction for identification of Escherichia coli, Escherichia albertii and Escherichia fergusonii.

Science.gov (United States)

Lindsey, Rebecca L; Garcia-Toledo, L; Fasulo, D; Gladney, L M; Strockbine, N

2017-09-01

Escherichia coli, Escherichia albertii, and Escherichia fergusonii are closely related bacteria that can cause illness in humans, such as bacteremia, urinary tract infections and diarrhea. Current identification strategies for these three species vary in complexity and typically rely on the use of multiple phenotypic and genetic tests. To facilitate their rapid identification, we developed a multiplex PCR assay targeting conserved, species-specific genes. We used the Daydreamer™ (Pattern Genomics, USA) software platform to concurrently analyze whole genome sequence assemblies (WGS) from 150 Enterobacteriaceae genomes (107 E. coli, 5 Shigella spp., 21 E. albertii, 12 E. fergusonii and 5 other species) and design primers for the following species-specific regions: a 212bp region of the cyclic di-GMP regulator gene (cdgR, AW869_22935 from genome K-12 MG1655, CP014225) for E. coli/Shigella; a 393bp region of the DNA-binding transcriptional activator of cysteine biosynthesis gene (EAKF1_ch4033 from genome KF1, CP007025) for E. albertii; and a 575bp region of the palmitoleoyl-acyl carrier protein (ACP)-dependent acyltransferase (EFER_0790 from genome ATCC 35469, CU928158) for E. fergusonii. We incorporated the species-specific primers into a conventional multiplex PCR assay and assessed its performance with a collection of 97 Enterobacteriaceae strains. The assay was 100% sensitive and specific for detecting the expected species and offers a quick and accurate strategy for identifying E. coli, E. albertii, and E. fergusonii in either a single reaction or by in silico PCR with sequence assemblies. Published by Elsevier B.V.

Epidemiology and clinical manifestations of enteroaggregative Escherichia coli

DEFF Research Database (Denmark)

Hebbelstrup Jensen, Betina; Olsen, Katharina E P; Struve, Carsten

2014-01-01

Enteroaggregative Escherichia coli (EAEC) represents a heterogeneous group of E. coli strains. The pathogenicity and clinical relevance of these bacteria are still controversial. In this review, we describe the clinical significance of EAEC regarding patterns of infection in humans, transmission...

Photoreactivable sector of lethal damage in ultraviolet-irradiated Escherichia coli cells

International Nuclear Information System (INIS)

Balgavy, P.

1976-01-01

The photoreactivable sector of lethal damage in Escherichia coli Bsub(s-1), Escherichia coli B/r Hcr - and Escherichia coli B/r Hcr + cells after ultraviolet irradiation at 254 nm is 0.823 +- 0.004, 0.70 +- 0.01 and 0.53 +- 0.06, respectively, at 99% confidence limits. For the low values of the photoreactivable sector in the B/r Hcr - and B/r Hcr + strains are likely to be responsible dark repair processes which eliminate lethal damage, brought about by pyrimidine dimers, preferably in comparison with lethal damage caused by photoproducts of another type. (author)

Escherichia coli as a probiotic?

NARCIS (Netherlands)

Jansen, GJ; Wildeboer-Veloo, ACM; van der Waaij, D; Degener, JE

1998-01-01

The influence of oral treatment with a suspension of non-pathogenic Escherichia coli cells (commercially available as: Symbioflor II(R)) on the morphological composition of the gut microflora and on the systemic humoral immune response (the IgG-, IgA- and IgM-isotype) against the bacterial cells in

The ins and outs of RND efflux pumps in Escherichia coli.

Science.gov (United States)

Anes, João; McCusker, Matthew P; Fanning, Séamus; Martins, Marta

2015-01-01

Infectious diseases remain one of the principal causes of morbidity and mortality in the world. Relevant authorities including the WHO and CDC have expressed serious concern regarding the continued increase in the development of multidrug resistance among bacteria. They have also reaffirmed the urgent need for investment in the discovery and development of new antibiotics and therapeutic approaches to treat multidrug resistant (MDR) bacteria. The extensive use of antimicrobial compounds in diverse environments, including farming and healthcare, has been identified as one of the main causes for the emergence of MDR bacteria. Induced selective pressure has led bacteria to develop new strategies of defense against these chemicals. Bacteria can accomplish this by several mechanisms, including enzymatic inactivation of the target compound; decreased cell permeability; target protection and/or overproduction; altered target site/enzyme and increased efflux due to over-expression of efflux pumps. Efflux pumps can be specific for a single substrate or can confer resistance to multiple antimicrobials by facilitating the extrusion of a broad range of compounds including antibiotics, heavy metals, biocides and others, from the bacterial cell. To overcome antimicrobial resistance caused by active efflux, efforts are required to better understand the fundamentals of drug efflux mechanisms. There is also a need to elucidate how these mechanisms are regulated and how they respond upon exposure to antimicrobials. Understanding these will allow the development of combined therapies using efflux inhibitors together with antibiotics to act on Gram-negative bacteria, such as the emerging globally disseminated MDR pathogen Escherichia coli ST131 (O25:H4). This review will summarize the current knowledge on resistance-nodulation-cell division efflux mechanisms in E. coli, a bacteria responsible for community and hospital-acquired infections, as well as foodborne outbreaks worldwide.

The Ins and Outs of RND Efflux Pumps in Escherichia coli

Directory of Open Access Journals (Sweden)

João eAnes

2015-06-01

Full Text Available Infectious diseases remain one of the principal causes of morbidity and mortality in the world. Relevant authorities including the WHO and CDC have expressed serious concern regarding the continued increase in the development of multidrug resistance among bacteria. They have also reaffirmed the urgent need for investment in the discovery and development of new antibiotics and therapeutic approaches to treat multidrug resistant (MDR bacteria.The extensive use of antimicrobial compounds in diverse environments, including farming and healthcare, has been identified as one of the main causes for the emergence of MDR bacteria. Induced selective pressure has led bacteria to develop new strategies of defence against these chemicals. Bacteria can accomplish this by several mechanisms, including enzymatic inactivation of the target compound; decreased cell permeability; target protection and/or overproduction; altered target site/enzyme and increased efflux due to over-expression of efflux pumps.Efflux pumps can be specific for a single substrate or can confer resistance to multiple antimicrobials by facilitating the extrusion of a broad range of compounds including antibiotics, heavy metals, biocides and others, from the bacterial cell. To overcome antimicrobial resistance caused by active efflux, efforts are required to better understand the fundamentals of drug efflux mechanisms. There is also a need to elucidate how these mechanisms are regulated and how they respond upon exposure to antimicrobials. Understanding these will allow the development of combined therapies using efflux inhibitors together with antibiotics to act on Gram-negative bacteria, such as the emerging globally disseminated MDR pathogen Escherichia coli ST131 (O25:H4. This review will summarise the current knowledge on resistance-nodulation-cell division efflux mechanisms in E. coli, a bacteria responsible for community and hospital-acquired infections, as well as foodborne

The ins and outs of RND efflux pumps in Escherichia coli

Science.gov (United States)

Anes, João; McCusker, Matthew P.; Fanning, Séamus; Martins, Marta

2015-01-01

Infectious diseases remain one of the principal causes of morbidity and mortality in the world. Relevant authorities including the WHO and CDC have expressed serious concern regarding the continued increase in the development of multidrug resistance among bacteria. They have also reaffirmed the urgent need for investment in the discovery and development of new antibiotics and therapeutic approaches to treat multidrug resistant (MDR) bacteria. The extensive use of antimicrobial compounds in diverse environments, including farming and healthcare, has been identified as one of the main causes for the emergence of MDR bacteria. Induced selective pressure has led bacteria to develop new strategies of defense against these chemicals. Bacteria can accomplish this by several mechanisms, including enzymatic inactivation of the target compound; decreased cell permeability; target protection and/or overproduction; altered target site/enzyme and increased efflux due to over-expression of efflux pumps. Efflux pumps can be specific for a single substrate or can confer resistance to multiple antimicrobials by facilitating the extrusion of a broad range of compounds including antibiotics, heavy metals, biocides and others, from the bacterial cell. To overcome antimicrobial resistance caused by active efflux, efforts are required to better understand the fundamentals of drug efflux mechanisms. There is also a need to elucidate how these mechanisms are regulated and how they respond upon exposure to antimicrobials. Understanding these will allow the development of combined therapies using efflux inhibitors together with antibiotics to act on Gram-negative bacteria, such as the emerging globally disseminated MDR pathogen Escherichia coli ST131 (O25:H4). This review will summarize the current knowledge on resistance-nodulation-cell division efflux mechanisms in E. coli, a bacteria responsible for community and hospital-acquired infections, as well as foodborne outbreaks worldwide

PENGARUH PERASAN DAUN BELIMBING WULUH (Averrhoa bilimbi TERHADAP PERTUMBUHAN BAKTERI Escherichia coli PATOGEN

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Fitrotin Azizah

2017-12-01

abstract  (Averrhoa bilimbi is one of the plants that can be used as an antibacterial, good flowers, stems, leaves and stems have benefits and efficacy. Chemical constituents of the leaves starfruit are tannins, flavonoids, saponins. The active ingredient in the leaves starfruit is tannin. Escherichia coli is a bacterium that causes diarrhea. From the above discussion, the authors raised the theme of Influence starfruit juice of the leaves on the growth of pathogenic E. coli bacteria. Formulation of the problem researchers is whether there is influence starfruit juice of the leaves on the growth of Escherichia coli pathogens. This study aims to determine the concentration that could inhibit and kill Esherichia coli Escherichia coli. This research is experimental. The sample used is leaf green starfruit not so young in a fresh state taken in the area around the boarding author Sutorejo 11B stay. In this study, the sample size for each treatment as much as 3 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10% and C (control. Independent variables are starfruit juice of the leaves, while the dependent variable growth of Escherichia coli. When the study carried out in January and July 2012. Data on the effect of starfruit juice of the leaves on the growth of Escherichia coli tested by laboratory examination and data collection techniques using Chi-Square 0:05. Based on the results it appears that at a concentration of 100% and 90% were able to kill the bacteria Escherichia coli, whereas the inhibitory power ranging from a concentration of 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%. From Chi-Square test was obtained λ2 count Escherichia coli pathogenic bacteria. Keyword : Leaves starfruit, E. Coli

Fosfomycin Resistance in Escherichia coli, Pennsylvania, USA.

Science.gov (United States)

Alrowais, Hind; McElheny, Christi L; Spychala, Caressa N; Sastry, Sangeeta; Guo, Qinglan; Butt, Adeel A; Doi, Yohei

2015-11-01

Fosfomycin resistance in Escherichia coli is rare in the United States. An extended-spectrum β-lactamase-producing E. coli clinical strain identified in Pennsylvania, USA, showed high-level fosfomycin resistance caused by the fosA3 gene. The IncFII plasmid carrying this gene had a structure similar to those found in China, where fosfomycin resistance is commonly described.

Neonatal infections caused by Escherichia coli at the National ...

African Journals Online (AJOL)

Background: Escherichia coli (E.coli) has been implicated as a common cause of both early and late onset neonatal infections. The emergence of different strains of E.coli that are multiply resistant to commonly used antibiotics has made continuous antibiotics surveillance relevant. Knowledge about common infections ...

neonatal infections caused by escherichia coli at the national

African Journals Online (AJOL)

boaz

Background: Escherichia coli (E.coli) has been implicated as a common cause of both early and late onset neonatal infections. The emergence of different strains of E.coli that are multiply resistant to commonly used antibiotics has made continuous antibiotics surveillance relevant. Knowledge about common infections ...

the occurrence of escherichia coli o157:h7 in market and abattoir

African Journals Online (AJOL)

user

Escherichia coli O157:H7 is a newly emerging pathogen frequently associated with the consumption of foods of ... KEY WORDS: E. coli O157:H7, Pathogen, Abattoir, Market, and Infections ..... pathogen. Escherichia coli O157:H7 as a model of.

Molecular Characterization of Multidrug Resistant Uropathogenic E. Coli Isolates from Jordanian Patients.

Science.gov (United States)

Nairoukh, Yacoub R; Mahafzah, Azmi M; Irshaid, Amal; Shehabi, Asem A

2018-01-01

Emergence of multi-drug resistant uropathogenic E. coli strains is an increasing problem to empirical treatment of urinary tract infections in many countries. This study investigated the magnitude of this problem in Jordan. A total of 262 E. coli isolates were recovered from urine samples of Jordanian patients which were suspected to have urinary tract infections (UTIs). All isolates were primarily identified by routine biochemical tests and tested for antimicrobial susceptibility by disc diffusion method. Fifty representative Multidrug Resistance (MDR) E. coli isolates to 3 or more antibiotic classes were tested for the presence of resistance genes of blaCTX-M- 1, 9 and 15, carbapenemase ( blaIMP, blaVIM, blaNDM-1, blaOXA-48 ), fluoroquinolones mutated genes ( parC and gyrA ) and clone of ST131 type using PCR methods. A total of 150/262 (57.3%) of E. coli isolates were MDR. Urine samples of hospitalized patients showed significantly more MDR isolates than outpatients. Fifty representative MDR E. coli isolates indicated the following molecular characteristics: All were positive for mutated parC gene and gyrA and for ST131 clone, and 78% were positive for genes of CTX-M-15 , 76% for CTX-M-I and for 8% CTX-M-9 , respectively. Additionally, all 50 MDR E. coli isolates were negative for carbapenemase genes ( blaIMP, blaVIM, blaNDM-1, blaOXA-48 ), except of one isolate was positive for blaKPC-2 . This study indicates alarming high rates recovery of MDR uropathogenic E. coli from Jordanian patients associated with high rates of positive ST131 clone, fluoroquinolone resistant and important types of blaCTX-M.

ESCHERICHIA COLI AND STAPHYLOCOCCUS AUREUS

African Journals Online (AJOL)

DR. AMINU

ABSTRACT. The bio-effects of the ethanol extracts from the leaf and stem of Momordica charantia were studied with the view to ascertain the medical usefulness ascribed to the plant by the locals. The plant parts, stem and leaf, revealed remarkable activity against Escherichia coli and Staphlococcus aureus. The leaves ...

Conjugal Pairing in Escherichia Coli

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 8. Conjugal Pairing in Escherichia Coli. Joshua Lederberg. Classics Volume 13 Issue 8 August 2008 pp 793-794. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/013/08/0793-0794 ...

Resistencia a los antimicrobianos de aislamientos de Escherichia coli obtenidos de cerdos de la República Argentina Antimicrobial resistance of Escherichia coli isolated from pigs in Argentina

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F.A. Moredo

2007-12-01

Full Text Available Se estudiaron 69 aislamientos de Escherichia coli provenientes de cerdos clínicamente sanos o con signología clínica no compatible con diarreas causadas por este microorganismo, con el objetivo de determinar el patrón de resistencia a los antimicrobianos frecuentemente utilizados en medicina veterinaria y humana. Se empleó el método de difusión en agar. Se observaron elevados porcentajes de resistencia frente a ampicilina, estreptomicina y tetraciclina, antimicrobianos utilizados en las explotaciones porcinas, y frente a trimetoprima-sulfametoxazol y cloranfenicol, compuestos que han dejado de utilizarse hace varios años. El 62% de los aislamientos mostró multirresistencia. Los resultados obtenidos en el presente trabajo corroboran la hipótesis de que la distribución fenotípica de la resistencia y, posiblemente, la de sus determinantes genéticos están directamente influenciadas por los tratamientos antimicrobianos utilizados.Sixty-nine Escherichia coli isolates from healthy pigs or with clinical signs non-compatible with diarrhea caused by this microorganism, were studied. The purpose was to determine the resistance profile against antimicrobials frequently used in veterinary and human medicine. The agar diffusion method was used. High resistance percentages against antimicrobials used in swine farms such as ampicillin, streptomycin and tetracycline were observed, as well as against trimetoprim-sulfametoxazole and chloramphenicol, compounds that were stopped being used several years ago. Sixty two percent of isolates showed multidrug-resistance. The results obtained in this work corroborate the hypothesis that the phenotypic distribution of resistance and possibly that of its genetic determinants, are directly influenced by the antimicrobial treatments used.

Microarray Evaluation of Antimicrobial Resistance and Virulence of Escherichia coli Isolates from Portuguese Poultry

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Nuno Mendonça

2016-01-01

Full Text Available The presence of antimicrobial resistance and virulence factors of 174 Escherichia coli strains isolated from healthy Portuguese Gallus gallus was evaluated. Resistance profiles were determined against 33 antimicrobials by microbroth dilution. Resistance was prevalent for tetracycline (70% and ampicillin (63%. Extended-spectrum beta-lactamase (ESBL phenotype was observed in 18% of the isolates. Multidrug resistance was found in 56% of isolates. A subset of 74 isolates were screened by DNA microarrays for the carriage of 88 antibiotic resistance genes and 62 virulence genes. Overall, 37 different resistance genes were detected. The most common were tet(A (72%, blaTEM (68%, and sul1 (47%, while 21% isolates harbored an ESBL gene (blaCTX-M group 1, group 2, or group 9. Of these, 96% carried the increased serum survival (iss virulence gene, while 89% presented the enterobactin siderophore receptor protein (iroN, 70% the temperature-sensitive hemagglutinin (tsh, and 68% the long polar fimbriae (lpfA virulence genes associated with extraintestinal pathogenic E. coli. In conclusion, prevalence of antibiotic resistant E. coli from the microbiota of Portuguese chickens was high, including to extended spectrum cephalosporins. The majority of isolates seems to have the potential to trigger extraintestinal human infection due to the presence of some virulence genes. However, the absence of genes specific for enteropathogenic E. coli reduces the risk for human intestinal infection.

Antibiotic resistance profile and virulence genes of uropathogenic Escherichia coli isolates in relation to phylogeny.

Science.gov (United States)

Adib, N; Ghanbarpour, R; Solatzadeh, H; Alizade, H

2014-03-01

Escherichia coli (E. coli) strains are the major cause of urinary tract infections (UTI) and belong to the large group of extra-intestinal pathogenic E. coli. The purposes of this study were to determine the antibiotic resistance profile, virulence genes and phylogenetic background of E. coli isolates from UTI cases. A total of 137 E. coli isolates were obtained from UTI samples. The antimicrobial susceptibility of confirmed isolates was determined by disk diffusion method against eight antibiotics. The isolates were examined to determine the presence and prevalence of selected virulence genes including iucD, sfa/focDE, papEF and hly. ECOR phylo-groups of isolates were determined by detection of yjaA and chuA genes and fragment TspE4.C2. The antibiogram results showed that 71% of the isolates were resistant to cefazolin, 60.42% to co-trimoxazole, 54.16% to nalidixic acid, 36.45% to gentamicin, 29.18% to ciprofloxacin, 14.58% to cefepime, 6.25% to nitrofurantoin and 0.00% to imipenem. Twenty-two antibiotic resistance patterns were observed among the isolates. Virulence genotyping of isolates revealed that 58.39% isolates had at least one of the four virulence genes. The iucD gene was the most prevalent gene (43.06%). The other genes including sfa/focDE, papEF and hly genes were detected in 35.76%, 18.97% and 2.18% isolates, respectively. Nine combination patterns of the virulence genes were detected in isolates. Phylotyping of 137 isolates revealed that the isolates fell into A (45.99%), B1 (13.14%), B2 (19.71%) and D (21.16%) groups. Phylotyping of multidrug resistant isolates indicated that these isolates are mostly in A (60.34%) and D (20.38%) groups. In conclusion, the isolates that possessed the iucD, sfa/focDE, papEF and hly virulence genes mostly belonged to A and B2 groups, whereas antibiotic resistant isolates were in groups A and D. Escherichia coli strains carrying virulence factors and antibiotic resistance are distributed in specific phylogenetic

Comparative analysis of antimicrobial resistance in enterotoxigenic Escherichia coli isolates from two paediatric cohort studies in Lima, Peru.

Science.gov (United States)

Medina, Anicia M; Rivera, Fulton P; Pons, Maria J; Riveros, Maribel; Gomes, Cláudia; Bernal, María; Meza, Rina; Maves, Ryan C; Huicho, Luis; Chea-Woo, Elsa; Lanata, Claudio F; Gil, Ana I; Ochoa, Theresa J; Ruiz, Joaquim

2015-08-01

Antibiotic resistance is increasing worldwide, being of special concern in low- and middle-income countries. The aim of this study was to determine the antimicrobial susceptibility and mechanisms of resistance in 205 enterotoxigenic Escherichia coli (ETEC) isolates from two cohort studies in children Peru. ETEC were identified by an in-house multiplex real-time PCR. Susceptibility to 13 antimicrobial agents was tested by disk diffusion; mechanisms of resistance were evaluated by PCR. ETEC isolates were resistant to ampicillin (64%), cotrimoxazole (52%), tetracycline (37%); 39% of the isolates were multidrug-resistant. Heat-stable toxin producing (ETEC-st) (48%) and heat-labile toxin producing ETEC (ETEC-lt) (40%) had higher rates of multidrug resistance than isolates producing both toxins (ETEC-lt-st) (21%), pPeru. However, further development of resistance should be closely monitored. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Research on killing Escherichia Coli by reactive oxygen species based on strong ionization discharging plasma

International Nuclear Information System (INIS)

Li, Y J; Tian, Y P; Zhang, Z T; Li, R H; Cai, L J; Gao, J Y

2013-01-01

Reactive oxygen species solution produced by strong ionization discharging plasma was used to kill Escherichia coli by spraying. Several effect factors such as pH value, solution temperature, spraying time and exposure time were observed in this study, and their effects on killing rate of Escherichia coli were discussed and analysed. Results show that the treating efficiency of ROS solution for Escherichia coli is higher in alkaline solution than that in acid solution. The killing rate of Escherichia coli increases while the spraying time and exposure time are longer and the temperature is lower. The effects of different factors on killing rate of Escherichia coli are as follows: spraying time > pH value > exposure time > solution temperature.

Photoexcited quantum dots for killing multidrug-resistant bacteria

Science.gov (United States)

Courtney, Colleen M.; Goodman, Samuel M.; McDaniel, Jessica A.; Madinger, Nancy E.; Chatterjee, Anushree; Nagpal, Prashant

2016-05-01

Multidrug-resistant bacterial infections are an ever-growing threat because of the shrinking arsenal of efficacious antibiotics. Metal nanoparticles can induce cell death, yet the toxicity effect is typically nonspecific. Here, we show that photoexcited quantum dots (QDs) can kill a wide range of multidrug-resistant bacterial clinical isolates, including methicillin-resistant Staphylococcus aureus, carbapenem-resistant Escherichia coli, and extended-spectrum β-lactamase-producing Klebsiella pneumoniae and Salmonella typhimurium. The killing effect is independent of material and controlled by the redox potentials of the photogenerated charge carriers, which selectively alter the cellular redox state. We also show that the QDs can be tailored to kill 92% of bacterial cells in a monoculture, and in a co-culture of E. coli and HEK 293T cells, while leaving the mammalian cells intact, or to increase bacterial proliferation. Photoexcited QDs could be used in the study of the effect of redox states on living systems, and lead to clinical phototherapy for the treatment of infections.

ESBL-Producing Escherichia coli

DEFF Research Database (Denmark)

Hertz, Frederik Boetius

Urinary tract infection (UTI) is one the most common bacterial infections and is regularly treated in primary health care. The most common cause of UTI is extraintestinal pathogenic Escherichia coli (ExPEC) already present in the intestinal microflora, often as the dominating strain. Resistance...... in E.coli is increasing and especially isolates producing Extended-Spectrum Beta-Lactamases (ESBL) have been reported worldwide. Treatment of UTI is usually initiated by the general practitioners and a significant proportion of clinical isolates are now resistant to first line antibiotics. The global...... to investigate (i) antibiotics involved in selection of ESBL-producing E.coli, in an experimental mouse model in vivo, (ii) risk factors for UTI with ESBL-producing E.coli and (iii) to describe the phylogenetic composition of E.coli populations with different resistance patterns. We found that different...

Multiplex PCR Assay for Identification of Human Diarrheagenic Escherichia coli

OpenAIRE

Toma, Claudia; Lu, Yan; Higa, Naomi; Nakasone, Noboru; Chinen, Isabel; Baschkier, Ariela; Rivas, Marta; Iwanaga, Masaaki

2003-01-01

A multiplex PCR assay for the identification of human diarrheagenic Escherichia coli was developed. The targets selected for each category were eae for enteropathogenic E. coli, stx for Shiga toxin-producing E. coli, elt and est for enterotoxigenic E. coli, ipaH for enteroinvasive E. coli, and aggR for enteroaggregative E. coli. This assay allowed the categorization of a diarrheagenic E. coli strain in a single reaction tube.

lactamases genes among0 Escherichia coli from patients with ...

African Journals Online (AJOL)

-lactamases (ESBLs) that mediate resistance to b-lactam drugs among Escherichia coli and other uropathogens have been reported worldwide. However, there is little information on the detection of ESBLs genes in E. coli from patients with ...

Human Intestinal Cells Modulate Conjugational Transfer of Multidrug Resistance Plasmids between Clinical Escherichia coli Isolates

DEFF Research Database (Denmark)

Machado, Ana Manuel; Sommer, Morten

2014-01-01

Bacterial conjugation in the human gut microbiota is believed to play a major role in the dissemination of antibiotic resistance genes and virulence plasmids. However, the modulation of bacterial conjugation by the human host remains poorly understood and there is a need for controlled systems...... to study this process. We established an in vitro co-culture system to study the interaction between human intestinal cells and bacteria. We show that the conjugation efficiency of a plasmid encoding an extended spectrum beta-lactamase is reduced when clinical isolates of Escherichia coli are co...... of the intestinal cells exposed to bacteria leading to a two-fold reduction in conjugation efficiency. These results show that human gut epithelial cells can modulate bacterial conjugation and may have relevance to gene exchange in the gut....

Resistance trends and risk factors of extended spectrum β-lactamases in Escherichia coli infections in Aleppo, Syria.

Science.gov (United States)

Al-Assil, Bodour; Mahfoud, Maysa; Hamzeh, Abdul Rezzak

2013-07-01

Recently, there has been a notable surge in urinary tract infections (UTIs) by extended spectrum β-lactamase (ESBL)-producing Escherichia coli, which considerably limits treatment options. This study aimed to determine prevalence, phenotypic patterns, and ESBL-production status of E coli in isolates from UTI patients along with uncovering locally relevant risk factors for contracting ESBL-producing E coli infections. One hundred four nonrepetitive urine samples were collected from 3 major hospitals in Aleppo, Syria. Antibiotic susceptibility and ESBL production were studied by disc diffusion and double disk synergy tests according to Clinical Laboratory Standards Institute guidelines. Epidemiologic analysis was done using χ(2) and multivariate logistic regression tests. This study revealed high prevalence of multidrug-resistant (MDR) E coli reaching 63%, whereas ESBL-producing E coli exceeded 52%. The latter exhibited alarmingly elevated levels of coresistance to non-β-lactam antibiotics leading to vast increase in MDR rates in comparison with non-ESBL-producing E coli (83.6% vs 12.2%, respectively). We found previous exposure to third-generation cephalosporins and fluoroquinolones to be a significant risk factor for ESBL-producing E coli infections, in addition to other known factors such as hospitalization and catheterization. Tigecycline and carbapenems demonstrated near perfect efficacy against tested E coli, so they rank high among treatment options. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Diarrheagenic Escherichia coli Markers and Phenotypes among Fecal E. coli Isolates Collected from Nicaraguan Infants ▿

OpenAIRE

Reyes, Daniel; Vilchez, Samuel; Paniagua, Margarita; Colque-Navarro, Patricia; Weintraub, Andrej; Möllby, Roland; Kühn, Inger

2010-01-01

We analyzed the prevalence of diarrheagenic Escherichia coli (DEC) markers and common phenotypes in 2,164 E. coli isolates from 282 DEC-positive samples. Enteropathogenic E. coli (EPEC) and enteroaggregative E. coli (EAEC) were very diverse and were not correlated with diarrhea. Enterotoxigenic E. coli (ETEC) estA and enterohemorrhagic E. coli (EHEC) belonged to a few phenotypes and were significantly correlated with diarrhea.

Colonization, resistance to bile, and virulence properties of Escherichia coli strains: Unusual characteristics associated with biliary tract diseases.

Science.gov (United States)

Razaghi, Maryam; Tajeddin, Elahe; Ganji, Leila; Alebouyeh, Masoud; Alizadeh, Amir Houshang Mohammad; Sadeghi, Amir; Zali, Mohammad Reza

2017-10-01

Escherichia coli is the species that is most frequently isolated from bile of patients with biliary tract diseases. This study was aimed to investigate any association between resistance and virulence properties of these isolates with occurrence of the diseases. A total of 102 bile samples were obtained from patients subjected to endoscopic retrograde cholangiopancreatography for different biliary diseases. Clinical data were collected and culture of the bile samples was done on selective media. Resistance of characterized Escherichia coli isolates to deoxycholate sodium (0-7%) and nineteen antibiotics was determined and PCR using 16 pairs of primers targeting stx1, stx2, exhA, eae, bfp, agg, pcvd432, lt, st, ipaH, pic, pet, ast, set, sen, and cdtB genes was done. Our results showed a statistically significant association between E. coli colonization and existence of common bile duct and gallbladder stones (p value 0.028). Out of the 22 E. coli strains (22/102) multidrug resistance phenotype was present in 95.45%. None of the strains belonged to common E. coli pathotypes. However, bfp + EhxA-hly, bfp + astA, bfp + EhxA-hly + pic, and EhxA-hly + pic + astA, bfp, and astA genotypes were detected in these strains. bfp (7/22, 31.8%) and astA (5/22, 22.7%) were among most frequent virulence factors in these strains. Results of this study showed significant association between colonization of E. coli and choledocholithiasis. Unusual existence of virulence gene combinations in these strains and their resistance to DOC and multiple classes of antibiotics could be considered as possible causes of their persistence in this harsh microenvironment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Escherichia coli growth modeling using neural network | Shamsudin ...

African Journals Online (AJOL)

technique that has the ability to predict with efficient and good performance. Using NARX, a highly accurate model was developed to predict the growth of Escherichia coli (E. coli) based on pH water parameter. The multiparameter portable sensor and spectrophotometer data were used to build and train the neural network.

FTIR nanobiosensors for Escherichia coli detection

Directory of Open Access Journals (Sweden)

Stefania Mura

2012-07-01

Full Text Available Infections due to enterohaemorrhagic E. coli (Escherichia coli have a low incidence but can have severe and sometimes fatal health consequences, and thus represent some of the most serious diseases due to the contamination of water and food. New, fast and simple devices that monitor these pathogens are necessary to improve the safety of our food supply chain. In this work we report on mesoporous titania thin-film substrates as sensors to detect E. coli O157:H7. Titania films treated with APTES ((3-aminopropyltriethoxysilane and GA (glutaraldehyde were functionalized with specific antibodies and the absorption properties monitored. The film-based biosensors showed a detection limit for E. coli of 1 × 102 CFU/mL, constituting a simple and selective method for the effective screening of water samples.

Hemolytic porcine intestinal Escherichia coli without virulence-associated genes typical of intestinal pathogenic E. coli.

Science.gov (United States)

Schierack, Peter; Weinreich, Joerg; Ewers, Christa; Tachu, Babila; Nicholson, Bryon; Barth, Stefanie

2011-12-01

Testing 1,666 fecal or intestinal samples from healthy and diarrheic pigs, we obtained hemolytic Escherichia coli isolates from 593 samples. Focusing on hemolytic E. coli isolates without virulence-associated genes (VAGs) typical for enteropathogens, we found that such isolates carried a broad variety of VAGs typical for extraintestinal pathogenic E. coli.

Annual Surveillance Summary: Escherichia coli (E. coli) Infections in the Military Health System (MHS), 2015

Science.gov (United States)

2017-03-01

Annual Surveillance Summary: Escherichia coli ( E . coli ) Infections in the Military Health System (MHS...or position of the Department of the Navy, Department of Defense, nor the U.S. Government. i i E . coli in the MHS: Annual Summary 2015 Prepared...March 2017 EpiData Center Department NMCPHC-EDC-TR-187-2017 ii ii E . coli in the MHS: Annual Summary 2015 Prepared March 2017 EpiData

Escherichia coli in broiler chickens with airsacculitis

Directory of Open Access Journals (Sweden)

Leandro S. Machado

2014-09-01

Full Text Available ABSTRACT. Machado L.S., do Nascimento E.R., Pereira V.L.A., Abreu D.L.C., Gouvea R. & Santos L.M.M. 2014. [Escherichia coli in broiler chickens with airsacculitis.] Escherichia coli em frangos de corte com aerossaculite. Revista Brasileira de Medicina Veterinária, 36(3:261-265, 2014. Departamento de Medicina Veterinária Preventiva e Saúde Pública, Faculdade de Veterinária, Universidade Federal Fluminense, Rua Dr. Vital Brazil Filho 64, Vital Brazil, Niterói, RJ 24230-340, Brazil. E-mail: leandromachadovet@yahoo.com.br The Brazilian poultry industry grows each year and becomes increasingly representative in the production and export of products. The health care with poultry have accompanied and favored this evolution, however, respiratory agents that affect the weight and carcass quality, continue to cause great damage to the poultry industry. Airsacculitis is considered the main cause of total and partial condemnation of carcasses of broilers, and has been attributed to Mycoplasmosis mostly caused by Mycoplasma gallisepticum (MG and Mycoplasma synoviae (MS and Escherichia coli. The aim of this study was to relate the positivity of MG / MS and E. coli detected by PCR as a risk factor for airsacculitis in condemnation of broilers in Health Inspection Service. We studied 30 broiler poultry slaughtered in a slaughterhouse under Federal Sanitary Inspection, located in the State of Rio de Janeiro. 30 chickens were randomly collected from different lots and tracheas obtained in each PCR. DNA was extracted by phenol-chloroform method and amplified using pairs of “primer”specific for MG, MS and E. coli. Of the 30 chickens analyzed by PCR, 30% (9/30 had lesions in air sacs. None of the birds showed infection with MG and/or MS PCR, however 33.3% (3/9 birds were positive for airsacculitis iss gene from E.coli. E.coli found in broiler chickens that were negative for mycoplasma airsacculitis, implying the presence of such bacteria may be sufficient

Thioredoxin from Escherichia coli

International Nuclear Information System (INIS)

Holmgren, A.; Ohlsson, I.; Grankvist, M.L.

1978-01-01

A competition radioimmunoassay for Escherichia coli thioredoxin using 125 I-labeled thioredoxin-S 2 and a double antibody technique was developed. The method permits determination of picomole amounts of thioredoxin in crude cell extracts and was used to study the localization of thioredoxin cell fractions. E. coli B was calculated to have approximately 10,000 copies of thioredoxin per cell mainly located in the soluble fraction after separation of the membrane and soluble fractions by gentle lysis and centrifugation. E. coli B tsnC mutants which are defective in the replication of phage T7 DNA in vivo and in vitro were examined for their content of thioredoxin. E. coli B tsnC 7004 contained no detectable level of thioredoxin in cell-free extracts examined under a variety of conditions. The results strongly suggest that tsnC 7004 is a nonsense or deletion mutant. Two other E. coli tsnC mutants, 7007 and 7008, contained detectable levels of thioredoxin in crude extracts as measured by thioredoxin reductase and gave similar immunoprecipitation reactions as the parent strain B/1. By radioimmunoassay incompletely cross-reacting material was present in both strains. These results show that tsnC 7007 and 7008 belong to a type of thioredoxin mutants with missence mutations in the thioredoxin gene affecting the function of thioredoxin as subunit in phage T7 DNA polymerase

ANTIMICIROBIAL SUSCEPTIBILITY PATTERNS OF Escherichia coli ...

African Journals Online (AJOL)

DR. AMINU

A total of 56 and 24 strains of E. coli and Shigella sp. isolated from children less than five years with diarrhoea attending 3 ... parasitic infections, as well as food intolerance, reaction to ..... Escherichia coil 0157:H7 as a model of entry of a new.

Distribution of Diverse Escherichia coli between Cattle and Pasture

OpenAIRE

NandaKafle, Gitanjali; Seale, Tarren; Flint, Toby; Nepal, Madhav; Venter, Stephanus N.; Brözel, Volker S.

2017-01-01

Escherichia coli is widely considered to not survive for extended periods outside the intestines of warm-blooded animals; however, recent studies demonstrated that E. coli strains maintain populations in soil and water without any known fecal contamination. The objective of this study was to investigate whether the niche partitioning of E. coli occurs between cattle and their pasture. We attempted to clarify whether E. coli from bovine feces differs phenotypically and genotypically from isola...

Frequency of escherichia coli in patients with community acquired urinary tract infection and their resistance pattern against some commonly used anti bacterials

International Nuclear Information System (INIS)

Ahmad, W.; Jamshed, F.; Ahmad, W.

2015-01-01

Urinary tract infection (UTI) is a very common health problem and Escherichia coli (E coli) are the most common organisms associated with community acquired UTI. Unfortunately these bacteria have developed extensive resistance against most of the commonly used anti-bacterials. The objective of this study was to determine the frequency and resistance pattern of E coli in patients of community acquired UTI in an area in northern part of Pakistan. Methods: Urine specimens were collected from patients who were clinically diagnosed as community acquired UTI. Urine routine examination (Urine RE) was done and samples positive for UTI (Pus cells >10/High Power Field) were included in the study. These samples were inoculated on Eosin Methylene Blue (EMB) agar plates and incubated at 37 degree C for 36 hours. Suspected colonies were then inoculated further on EMB plates for pure cultures of E coli characterized by certain morphological characteristics. IMViC was applied for the confirmation of E coli. In vitro antibiotic susceptibility tests of E coli were performed with standardized commercial susceptibility discs (OXOID). Results: Out of 50 specimens, positive for UTI by urine RE, 20 showed pure growth of E coli on culture (40%). The majority of the isolates (28%; n=14) were from women while only 12% (n=6) were from men. Escherichia coli showed a high rate of resistance towards Ampicillin (90%), Tetracycline (70%), Erythromycin (70%) and Trimethoprim-Sulfamethoxazole (55%). Sparfloxacin showed better results (45%) than ciprofloxacin (50%). Out of 20 E coli isolates, two (10%) were resistant to all the antibacterials except chloramphenicol, eight isolates (40%) showed resistance to six or more than six while 14 (70%) were resistant to four or more than four drugs. Conclusion: Rate of resistance of E coli against commonly used antibacterials was quite high and majority of the strains showed multidrug resistance. (author)

(ESBL) producing Escherichia coli and Klebsiella pneumoniae

African Journals Online (AJOL)

use

2011-11-21

Nov 21, 2011 ... the most common serious bacterial infections in infants ... UTI is a common cause of morbidity .... of ESBL and non-ESBL producing Escherichia coli and Klebsiella pneumonia. ... in hospital and community acquired infections.

Antimicrobial resistance in equine faecal Escherichia coli isolates from North West England

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Williams Nicola J

2010-04-01

Full Text Available Abstract Background Escherichia coli isolates of equine faecal origin were investigated for antibiotic resistance, resistance genes and their ability to perform horizontal transfer. Methods In total, 264 faecal samples were collected from 138 horses in hospital and community livery premises in northwest England, yielding 296 resistant E. coli isolates. Isolates were tested for susceptibility to antimicrobial drugs by disc diffusion and agar dilution methods in order to determine minimum inhibitory concentrations (MIC. PCR amplification was used to detect genes conferring resistance to: ampicillin (TEM and SHV beta-lactamase, chloramphenicol (catI, catII, catIII and cml, tetracycline (tetA, tetB, tetC, tetD, tet E and tetG, and trimethoprim (dfrA1, dfrA9, dfrA12, dfrA13, dfr7, and dfr17. Results The proportion of antibiotic resistant isolates, and multidrug resistant isolates (MDR was significantly higher in hospital samples compared to livery samples (MDR: 48% of hospital isolates; 12% of livery isolates, p dfr, TEM beta-lactamase, tet and cat, conferring resistance to trimethoprim, ampicillin, tetracycline and chloramphenicol, respectively. Within each antimicrobial resistance group, these genes occurred at frequencies of 93% (260/279, 91%, 86.8% and 73.5%, respectively; with 115/296 (38.8% found to be MDR isolates. Conjugation experiments were performed on selected isolates and MDR phenotypes were readily transferred. Conclusions Our findings demonstrate that E. coli of equine faecal origin are commonly resistant to antibiotics used in human and veterinary medicine. Furthermore, our results suggest that most antibiotic resistance observed in equine E. coli is encoded by well-known and well-characterized resistant genes common to E. coli from man and domestic animals. These data support the ongoing concern about antimicrobial resistance, MDR, antimicrobial use in veterinary medicine and the zoonotic risk that horses could potentially pose to

Antimicrobial susceptibilities of avian Escherichia coli isolates in ...

African Journals Online (AJOL)

Colibacillosis is a poultry disease of economic importance in Iran and all around the world. The aim of this study is to test the antibiotic sensitivity of Escherichia coli strains which were isolated in Tabriz. A total of 100 E. coli strains isolated from avian colibacillosis of 50 farms from 2008 to 2009 in Tabriz, were investigated for ...

PART I. ESCHERICHIA COLI

Directory of Open Access Journals (Sweden)

Sanaa Mahdi Oraibi

2016-11-01

Full Text Available The presence of Escherichia coli in the air of facilities involved in management and composting of post-slaughter poultry wastes in selected plants of West Western Pomerania region was studied. Measurements were made on four dates in a variety of weather conditions during the year. The study was conducted at 5 objects that differ in the type of waste and the degree of preparation for composting. These were: chemical treatment and preliminary processing plant, liquid wastes reservoir, platform for preparation of materials for composting, storage of biological sediments, and composting facility. Measurement of bacteria count was carried out in accordance with the applicable procedures on selective chromogenic TBX medium. The assays revealed the presence of E. coli at all test objects, but not always on all measurement dates. It has been shown that the presence of E. coli was from 20 to 3047 CFU∙m-3 of air, although the largest quantities were most frequently detected in the air of the building for post-slaughter waste pre-treatment in chemical treatment plant.

Findings of Escherichia coli and Enterococcus spp. in homemade cheese

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Tambur Zoran

2007-01-01

Full Text Available During the period from February until March 2004, 108 samples of soft cheese originating from markets of Pancevo, Subotica and Belgrade were examined. Microbiological analyses of the cheese samples to the presence of Escherichia coli was performed using methods described in the Regulations on methods for performing microbiological analyses and super analyses of consumer articles, while the presence of bacteria Enteroccocus spp. was performed on the dexter agar. From 108 samples of soft cheese from the territories of Pancevo, Belgrade and Subotica were isolated: Enterococcus spp. from 96% and Escherichia coli from 69%, cheese samples. Verocytotoxic E.coli was not isolated from any of the taken cheese samples.

Escherichia coli pyomyositis in an immunocompromised host.

Science.gov (United States)

Sharma, Umesh; Schwan, William R; Agger, William A

2011-08-01

Pyomyositis due to Escherichia coli (E. coil) is rarely reported in immunocompromised patients with hematological malignancy. We present a case report of a 34-year-old man who developed E. coli pyomyositis as a complication of acute myelogenous leukemia (AML). Magnetic resonance imaging (MRI) of the right hip suggested myofascial infection of the gluteal muscles, and a needle muscle aspiration grew E. coli phylogenetic group B2. The patient responded to intravenous piperacillin/tazobactam followed by prolonged oral levofloxacin. Pyomyositis should be suspected in all immunocompromised patients complaining of muscle pain and may exhibit signs of localized muscle infection. Appropriate antibiotic therapy targeting fluoroquinolone-resistant E. coli should be considered for initial empiric therapy of pyomyositis in immunocompromised patients.

Infectious endocarditis caused by Escherichia coli

DEFF Research Database (Denmark)

Lauridsen, Trine Kiilerich; Arpi, Magnus; Fritz-Hansen, Thomas

2011-01-01

Although Escherichia coli is among the most common causes of Gram-negative bacteraemia, infectious endocarditis (IE) due to this pathogen is rare. A 67-y-old male without a previous medical history presented with a new mitral regurgitation murmur and persisting E. coli bacteraemia in spite of broad......-spectrum intravenous antibiotics. Transthoracic and transoesophageal echocardiography revealed a severe mitral endocarditis. E. coli DNA was identified from the mitral valve and the vegetation, and no other pathogen was found. The case was further complicated by spondylodiscitis and bilateral endophthalmitis. Extra......-intestinal pathogenic E. coli (ExPEC) are able to colonize tissue outside the gastrointestinal tract and contain a variety of virulence factors that may enable the pathogens to invade and induce infections in the cardiac endothelia. In these cases echocardiography as the imaging technology is of paramount importance...

Mutagenic DNA repair in Escherichia coli

International Nuclear Information System (INIS)

Bridges, B.A.; Sharif, Firdaus

1986-01-01

The authors report a study of the misincorporation step in excision proficient umuC Escherichia coli as revealed by delayed photoreversal and show that it parallels the loss of photoreversibility of mutations induced in isogenic umu + bacteria; in both cases the end-point was mutation to streptomycin resistance. (author)

Molecular characterization and antimicrobial resistance of faecal and urinary Escherichia coli isolated from dogs and humans in Italy

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Clara Tramuta

2014-03-01

Full Text Available During this study, 109 faecal Escherichia coli samples isolated from 61 dogs and 48 humans were characterised according to phylogenetic group, extraintestinal virulence factors and antibiotic resistance. The isolates from dogs were predominantly distributed within phylogroup B1 (36%, while the majority of human strains belonged to phylogroup B2 (54%. The prevalence of cnf1, hlyA, papC and sfa virulence genes was significantly associated with the group B2. Canine isolates showed multidrug resistance (MDR more frequently than human strains. Since group B2 contains most of the strains that cause extraintestinal infections, all 46 B2 faecal strains were confronted against an addition population of 57 urinary E. coli strains belonging to the same phylogroup. The comparison shows that there was no significant difference in the occurrence of virulence factors or in the distribution of antibiotic resistance between faecal and urinary E. coli isolates fromd dogs. At the same time, a highly significant association was detected between multiple resistence and the source of the strains and between MDR and E. coli isolated from urine in human. This study highlighted similar features of E. coli isolated across sources and hosts. The data suggest a high prevalence of antibiotic resistance in faecal strains, which may represent a serious health risk since these strains can function as a reservoir for uropathogenic E. coli.

Geraniol Restores Antibiotic Activities against Multidrug-Resistant Isolates from Gram-Negative Species▿ †

Science.gov (United States)

Lorenzi, Vannina; Muselli, Alain; Bernardini, Antoine François; Berti, Liliane; Pagès, Jean-Marie; Amaral, Leonard; Bolla, Jean-Michel

2009-01-01

The essential oil of Helichrysum italicum significantly reduces the multidrug resistance of Enterobacter aerogenes, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. Combinations of the two most active fractions of the essential oil with each other or with phenylalanine arginine β-naphthylamide yield synergistic activity. Geraniol, a component of one fraction, significantly increased the efficacy of β-lactams, quinolones, and chloramphenicol. PMID:19258278

Effect of high pressurized carbon dioxide on Escherichia coli ...

African Journals Online (AJOL)

Carbon dioxide at high pressure can retard microbial growth and sometimes kill microorganisms depending on values of applied pressure, temperature and exposure time. In this study the effect of high pressurised carbon dioxide (HPCD) on Escherichia coli was investigated. Culture of E. coli was subjected to high ...

Prevalence of Aeromonas species and Escherichia coli in stool ...

African Journals Online (AJOL)

Background: Diarrhoea is one of the main causes of mortality and morbidity in childhood. Bacterial diarrhoea is a common disorder. Aeromonas species and Escherichia coli (E. coli) are some of the aetiological agents associated with diarrhoea in children. Objective: To determine the prevalence of Aeromonas species and ...

Detection of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Market-Ready Chickens in Zambia.

Science.gov (United States)

Chishimba, K; Hang'ombe, B M; Muzandu, K; Mshana, S E; Matee, M I; Nakajima, C; Suzuki, Y

2016-01-01

The frequent administering of antibiotics in the treatment of poultry diseases may contribute to emergence of antimicrobial-resistant strains. The objective of this study was to detect the presence of extended-spectrum β-lactamase- (ESBL-) producing Escherichia coli in poultry in Zambia. A total of 384 poultry samples were collected and analyzed for ESBL-producing Escherichia coli. The cultured E. coli isolates were subjected to antimicrobial susceptibility tests and the polymerase chain reaction for detection of bla CTX-M, bla SHV, and bla TEM genes. Overall 20.1%, 77/384, (95% CI; 43.2-65.5%) of total samples analyzed contained ESBL-producing Escherichia coli. The antimicrobial sensitivity test revealed that 85.7% (66/77; CI: 75.7-92) of ESBL-producing E. coli isolates conferred resistance to beta-lactam and other antimicrobial agents. These results indicate that poultry is a potential reservoir for ESBL-producing Escherichia coli. The presence of ESBL-producing Escherichia coli in poultry destined for human consumption requires strengthening of the antibiotic administering policy. This is important as antibiotic administration in food animals is gaining momentum for improved animal productivity in developing countries such as Zambia.

Detection of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Market-Ready Chickens in Zambia

Directory of Open Access Journals (Sweden)

K. Chishimba

2016-01-01

Full Text Available The frequent administering of antibiotics in the treatment of poultry diseases may contribute to emergence of antimicrobial-resistant strains. The objective of this study was to detect the presence of extended-spectrum β-lactamase- (ESBL- producing Escherichia coli in poultry in Zambia. A total of 384 poultry samples were collected and analyzed for ESBL-producing Escherichia coli. The cultured E. coli isolates were subjected to antimicrobial susceptibility tests and the polymerase chain reaction for detection of blaCTX-M, blaSHV, and blaTEM genes. Overall 20.1%, 77/384, (95% CI; 43.2–65.5% of total samples analyzed contained ESBL-producing Escherichia coli. The antimicrobial sensitivity test revealed that 85.7% (66/77; CI: 75.7–92 of ESBL-producing E. coli isolates conferred resistance to beta-lactam and other antimicrobial agents. These results indicate that poultry is a potential reservoir for ESBL-producing Escherichia coli. The presence of ESBL-producing Escherichia coli in poultry destined for human consumption requires strengthening of the antibiotic administering policy. This is important as antibiotic administration in food animals is gaining momentum for improved animal productivity in developing countries such as Zambia.

Comparative Genomic Analysis of Globally Dominant ST131 Clone with Other Epidemiologically Successful Extraintestinal Pathogenic Escherichia coli (ExPEC Lineages

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Sabiha Shaik

2017-10-01

Full Text Available Escherichia coli sequence type 131 (ST131, a pandemic clone responsible for the high incidence of extraintestinal pathogenic E. coli (ExPEC infections, has been known widely for its contribution to the worldwide dissemination of multidrug resistance. Although other ExPEC-associated and extended-spectrum-β-lactamase (ESBL-producing E. coli clones, such as ST38, ST405, and ST648 have been studied widely, no comparative genomic data with respect to other genotypes exist for ST131. In this study, comparative genomic analysis was performed for 99 ST131 E. coli strains with 40 genomes from three other STs, including ST38 (n = 12, ST405 (n = 10, and ST648 (n = 18, and functional studies were performed on five in-house strains corresponding to the four STs. Phylogenomic analysis results from this study corroborated with the sequence type-specific clonality. Results from the genome-wide resistance profiling confirmed that all strains were inherently multidrug resistant. ST131 genomes showed unique virulence profiles, and analysis of mobile genetic elements and their associated methyltransferases (MTases has revealed that several of them were missing from the majority of the non-ST131 strains. Despite the fact that non-ST131 strains lacked few essential genes belonging to the serum resistome, the in-house strains representing all four STs demonstrated similar resistance levels to serum antibactericidal activity. Core genome analysis data revealed that non-ST131 strains usually lacked several ST131-defined genomic coordinates, and a significant number of genes were missing from the core of the ST131 genomes. Data from this study reinforce adaptive diversification of E. coli strains belonging to the ST131 lineage and provide new insights into the molecular mechanisms underlying clonal diversification of the ST131 lineage.

Identification of natural compound inhibitors for multidrug efflux pumps of Escherichia coli and Pseudomonas aeruginosa using in silico high-throughput virtual screening and in vitro validation.

Science.gov (United States)

Aparna, Vasudevan; Dineshkumar, Kesavan; Mohanalakshmi, Narasumani; Velmurugan, Devadasan; Hopper, Waheeta

2014-01-01

Pseudomonas aeruginosa and Escherichia coli are resistant to wide range of antibiotics rendering the treatment of infections very difficult. A main mechanism attributed to the resistance is the function of efflux pumps. MexAB-OprM and AcrAB-TolC are the tripartite efflux pump assemblies, responsible for multidrug resistance in P. aeruginosa and E. coli respectively. Substrates that are more susceptible for efflux are predicted to have a common pharmacophore feature map. In this study, a new criterion of excluding compounds with efflux substrate-like features was used, thereby refining the selection process and enriching the inhibitor identification process. An in-house database of phytochemicals was created and screened using high-throughput virtual screening against AcrB and MexB proteins and filtered by matching with the common pharmacophore models (AADHR, ADHNR, AAHNR, AADHN, AADNR, AAADN, AAADR, AAANR, AAAHN, AAADD and AAADH) generated using known efflux substrates. Phytochemical hits that matched with any one or more of the efflux substrate models were excluded from the study. Hits that do not have features similar to the efflux substrate models were docked using XP docking against the AcrB and MexB proteins. The best hits of the XP docking were validated by checkerboard synergy assay and ethidium bromide accumulation assay for their efflux inhibition potency. Lanatoside C and diadzein were filtered based on the synergistic potential and validated for their efflux inhibition potency using ethidium bromide accumulation study. These compounds exhibited the ability to increase the accumulation of ethidium bromide inside the bacterial cell as evidenced by these increase in fluorescence in the presence of the compounds. With this good correlation between in silico screening and positive efflux inhibitory activity in vitro, the two compounds, lanatoside C and diadzein could be promising efflux pump inhibitors and effective to use in combination therapy against drug

Identification of natural compound inhibitors for multidrug efflux pumps of Escherichia coli and Pseudomonas aeruginosa using in silico high-throughput virtual screening and in vitro validation.

Directory of Open Access Journals (Sweden)

Vasudevan Aparna

Full Text Available Pseudomonas aeruginosa and Escherichia coli are resistant to wide range of antibiotics rendering the treatment of infections very difficult. A main mechanism attributed to the resistance is the function of efflux pumps. MexAB-OprM and AcrAB-TolC are the tripartite efflux pump assemblies, responsible for multidrug resistance in P. aeruginosa and E. coli respectively. Substrates that are more susceptible for efflux are predicted to have a common pharmacophore feature map. In this study, a new criterion of excluding compounds with efflux substrate-like features was used, thereby refining the selection process and enriching the inhibitor identification process. An in-house database of phytochemicals was created and screened using high-throughput virtual screening against AcrB and MexB proteins and filtered by matching with the common pharmacophore models (AADHR, ADHNR, AAHNR, AADHN, AADNR, AAADN, AAADR, AAANR, AAAHN, AAADD and AAADH generated using known efflux substrates. Phytochemical hits that matched with any one or more of the efflux substrate models were excluded from the study. Hits that do not have features similar to the efflux substrate models were docked using XP docking against the AcrB and MexB proteins. The best hits of the XP docking were validated by checkerboard synergy assay and ethidium bromide accumulation assay for their efflux inhibition potency. Lanatoside C and diadzein were filtered based on the synergistic potential and validated for their efflux inhibition potency using ethidium bromide accumulation study. These compounds exhibited the ability to increase the accumulation of ethidium bromide inside the bacterial cell as evidenced by these increase in fluorescence in the presence of the compounds. With this good correlation between in silico screening and positive efflux inhibitory activity in vitro, the two compounds, lanatoside C and diadzein could be promising efflux pump inhibitors and effective to use in combination

Synergistic effects in mixed Escherichia coli biofilms

DEFF Research Database (Denmark)

Reisner, A.; Holler, B.M.; Molin, Søren

2006-01-01

Bacterial biofilms, often composed of multiple species and genetically distinct strains, develop under complex influences of cell-cell interactions. Although detailed knowledge about the mechanisms underlying formation of single-species laboratory biofilms has emerged, little is known about...... the pathways governing development of more complex heterogeneous communities. In this study, we established a laboratory model where biofilm-stimulating effects due to interactions between genetically diverse strains of Escherichia coli were monitored. Synergistic induction of biofilm formation resulting from...... the cocultivation of 403 undomesticated E. coli strains with a characterized E. coli K-12 strain was detected at a significant frequency. The survey suggests that different mechanisms underlie the observed stimulation, yet synergistic development of biofilm within the subset of E. coli isolates (n = 56) exhibiting...

Multiple-Resistant Commensal Escherichia Coli from Nigerian ...

African Journals Online (AJOL)

Purpose: The antimicrobial susceptibility and virulence traits of 150 strains of Escherichia coli ... and ethical approval was obtained from the Health .... persist in the guts by virtue of the ability of such ... cases of diarrhoea in Ile-Ife and environs.

Synthesis and processing of escherichia-coli tem-beta-lactamase and bacillus-licheniformis alpha-amylase in escherichia-coli : The role of signal peptidase-i

NARCIS (Netherlands)

van Dijl, J M; Smith, H; Bron, Sierd; Venema, Gerard

A mutant of Escherichia coli, in which signal peptidase I synthesis can be regulated, was constructed. The mutant was used to study the effects of signal peptidase I limitation on the synthesis and efficiency of processing of two proteins: the periplasmic E. coli TEM-beta-lactamase and Bacillus

SYNTHESIS AND PROCESSING OF ESCHERICHIA-COLI TEM-BETA-LACTAMASE AND BACILLUS-LICHENIFORMIS ALPHA-AMYLASE IN ESCHERICHIA-COLI : THE ROLE OF SIGNAL PEPTIDASE-I

NARCIS (Netherlands)

van Dijl, J M; SMITH, H; BRON, S; VENEMA, G

A mutant of Escherichia coli, in which signal peptidase I synthesis can be regulated, was constructed. The mutant was used to study the effects of signal peptidase I limitation on the synthesis and efficiency of processing of two proteins: the periplasmic E. coli TEM-beta-lactamase and Bacillus

Changes in Escherichia coli resistance to co-trimoxazole in ...

African Journals Online (AJOL)

In Thyolo district, Malawi, an operational research study is being conducted on the efficacy and feasibility of co-trimoxazole prophylaxis in preventing deaths in HIV-positive patients with tuberculosis (TB). A series of cross-sectional studies were carried out to determine i) whether faecal Escherichia coli (E.coli) resistance to ...

Fecal Microbiota Transplantation Inhibits Multidrug-Resistant Gut Pathogens: Preliminary Report Performed in an Immunocompromised Host.

Science.gov (United States)

Biliński, Jarosław; Grzesiowski, Paweł; Muszyński, Jacek; Wróblewska, Marta; Mądry, Krzysztof; Robak, Katarzyna; Dzieciątkowski, Tomasz; Wiktor-Jedrzejczak, Wiesław; Basak, Grzegorz W

2016-06-01

Colonization of the gastrointestinal tract with multidrug-resistant (MDR) bacteria is a consequence of gut dysbiosis. We describe the successful utilization of fecal microbiota transplantation to inhibit Klebsiella pneumoniae MBL(+) and Escherichia coli ESBL(+) gut colonization in the immunocompromised host as a novel tool in the battle against MDR microorganisms. ClinicalTrials.gov identifier NCT02461199.

Potential public health significance of faecal contamination and multidrug-resistant Escherichia coli and Salmonella serotypes in a lake in India.

Science.gov (United States)

Abhirosh, C; Sherin, V; Thomas, A P; Hatha, A A M; Mazumder, A

2011-06-01

To assess the prevalence of faecal coliform bacteria and multiple drug resistance among Escherichia coli and Salmonella serotypes from Vembanadu Lake. Systematic microbiological testing. Monthly collection of water samples were made from ten stations on the southern and northern parts of a salt water regulator constructed in Vembanadu Lake in order to prevent incursion of seawater during certain periods of the year. Density of faecal colifrom bacteria was estimated. E. coli and Salmonella were isolated and their different serotypes were identified. Antibiotic resistance analysis of E. coli and Salmonella serotypes was done and the MAR index of individual isolates was calculated. Density of faecal coliform bacteria ranged from mean MPN value 2900 -7100/100ml. Results showed multiple drug resistance pattern among the bacterial isolates. E. coli showed more than 50% resistance to amickacin, oxytetracycline, streptomycin, tetracycline and kanamycin while Salmonella showed high resistance to oxytetracycline, streptomycin, tetracycline and ampicillin. The MAR indexing of the isolates showed that they have originated from high risk source such as humans, poultry and dairy cows. The high density of faecal coliform bacteria and prevalence of multi drug resistant E. coli and Salmonella serotypes in the lake may pose severe public health risk through related water borne and food borne outbreaks. Copyright © 2011 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Isolation and genomic characterization of Escherichia coli O157:NM ...

African Journals Online (AJOL)

Human diseases caused by Escherichia coli O157:NM and E. coli O157:H7 strains have been reported throughout the world. In developed countries, serotype O157:H7 represents the major cause of human diseases; however, there have been increasing reports of non-O157 Shiga toxin (Stx)-producing E. coli strains ...

Escherichia coli. A sanitary methodology for faecal water pollution tests; Escherichia coli nelle acque. Significato sanitario e metodologie di analisi

Energy Technology Data Exchange (ETDEWEB)

Bonadonna, L. [Istituto Superiore di Sanita' , Rome (Italy)

2001-02-01

Among the traditional indictors of faecal water pollution, Escherichia coli has shown to fit better with the definition of indicator organism. Till now its recovery has been time-consuming and needs confirmation tests. In this report more rapid and direct methods, based on enzymatic reactions, are presented. [Italian] Per talune peculiari caratteristiche, Escherichia coli sembra meglio soddisfare i requisiti insiti nella definizione di organismo indicatore, rispetto ai tradizionali indicatori di contaminazione fecale dell'acqua. Finora, i substrati disponibili per il suo rilevamento necessitano tutti di almeno una prova di conferma. Di qui l'esigenza di indicare metodi di rilevamento a riposta piu' rapida, anche in relazione all'inserimento, nelle piu' recenti normative nazionali ed europee, del microrganismo tra i parametri microbiologici da ricercare.

Predictors Of Non-Escherichia Coli Urinary Tract Infection.

Science.gov (United States)

Shaikh, Nader; Wald, Ellen R; Keren, Ron; Gotman, Nathan; Ivanova, Anastasia; Carpenter, Myra A; Moxey-Mims, Marva; Hoberman, Alejandro

2016-11-01

We aimed to determine which children are prone to non-Escherichia coli urinary tract infection (UTIs). We included 769 children with UTI. We found that circumcised males, Hispanic children, children without fever and children with grades 3 and 4 vesicoureteral reflux were more likely to have a UTI caused by organisms other than E. coli. This information may guide clinicians in their choice of antimicrobial therapy.

Photoreactivating enzyme from Escherichia coli

International Nuclear Information System (INIS)

Snapka, R.M.; Fuselier, C.O.

1977-01-01

Escherichia coli photoreactivating enzyme (PRE) has been purified in large amounts from an E.coli strain lysogenic for a defective lambda bacteriophage carrying the phr gene. The resulting enzyme had a pH optimum of 7.2 and an ionic strength optimum of 0.18. It consisted of an apoprotein and cofactor, both of which were necessary for catalytic activity. The apoprotein had a monomer molecular weight of 35,200 and showed stable aggregates under denaturing conditions. The amino acid analysis of the E.coli enzyme was very similar to that of the photoreactivating enzyme from orchid seedlings (Cattelya aurantiaca). Both had arginine at the amino terminus. The cofactor, like the holoenzyme, showed absorption, magnetic circular dichroism, and emission properties indicative of an adenine moiety. Although the isolated enzyme had an action spectrum which peaked at about 360 nm, neither the cofactor, apoenzyme nor holoenzyme showed any detectable absorption between 300 and 400 nm. (author)

Photoreactivating enzyme from Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Snapka, R M; Fuselier, C O [California Univ., Irvine (USA)

1977-05-01

Escherichia coli photoreactivating enzyme (PRE) has been purified in large amounts from an E.coli strain lysogenic for a defective lambda bacteriophage carrying the phr gene. The resulting enzyme had a pH optimum of 7.2 and an ionic strength optimum of 0.18. It consisted of an apoprotein and cofactor, both of which were necessary for catalytic activity. The apoprotein had a monomer molecular weight of 35,200 and showed stable aggregates under denaturing conditions. The amino acid analysis of the E.coli enzyme was very similar to that of the photoreactivating enzyme from orchid seedlings (Cattelya aurantiaca). Both had arginine at the amino terminus. The cofactor, like the holoenzyme, showed absorption, magnetic circular dichroism, and emission properties indicative of an adenine moiety. Although the isolated enzyme had an action spectrum which peaked at about 360 nm, neither the cofactor, apoenzyme nor holoenzyme showed any detectable absorption between 300 and 400 nm.

Multidrug resistance in pediatric urinary tract infections.

Science.gov (United States)

Gaspari, Romolo J; Dickson, Eric; Karlowsky, James; Doern, Gary

2006-01-01

Urinary tract infections (UTIs) represent a common infection in the pediatric population. Escherichia coli is the most common uropathogen in children, and antimicrobial resistance in this species complicates the treatment of pediatric UTIs. Despite the impact of resistance on empiric antibiotic choice, there is little data on multidrug resistance in pediatric patients. In this paper, we describe characteristics of multidrug-resistant E. coli in pediatric patients using a large national database of uropathogens antimicrobial sensitivities. Antimicrobial susceptibility patterns to commonly prescribed antibiotics were performed on uropathogens isolated from children presenting to participating hospitals between 1999 and 2001. Data were analyzed separately for four pediatric age groups. Single and multidrug resistance to ampicillin, amoxicillin-clavulanate, cefazolin, ciprofloxacin, nitrofurantoin, and trimethoprim-sulfamethoxazole (TMP-SMX) were performed on all specimens. There were a total of 11,341 E. coli urine cultures from 343 infants (0-4 weeks), 1,801 toddlers (5 weeks-24 months), 6,742 preteens (2-12 years), and 2,455 teens (13-17 years). E. coli resistance to ampicillin peaked in toddlers (52.8%) but was high in preteens (52.1%), infants (50.4%), and teens (40.6%). Resistance to two or more antibiotics varied across age groups, with toddlers (27%) leading preteens (23.1%), infants (21%), and teens (15.9%). Resistance to three or more antibiotics was low in all age groups (range 3.1-5.2%). The most common co-resistance in all age groups was ampicillin/TMP-SMZ. In conclusion, less than half of all pediatric UTIs are susceptible to all commonly used antibiotics. In some age groups, there is a significant percentage of co-resistance between the two most commonly used antibiotics (ampicillin and TMP-SMZ).

Vaginal Lactobacillus isolates inhibit uropathogenic Escherichia coli.

OpenAIRE

Atassi , Fabrice; Brassart , Dominique; Grob , Philipp; Graf , Federico; Servin , Alain ,

2006-01-01

The purpose of this study was to investigate the antibacterial activities of Lactobacillus jensenii KS119.1 and KS121.1, and Lactobacillus gasserii KS120.1 and KS124.3 strains isolated from the vaginal microflora of healthy women, against uropathogenic, diffusely adhering Afa/Dr Escherichia coli (Afa/Dr DAEC) strains IH11128 and 7372 involved in recurrent cystitis. We observed that some of the Lactobacillus isolates inhibited the growth and decreased the viability of E. coli IH11128 and 7372....

Growth modeling of uropathogenic Escherichia coli in ground chicken meat

Science.gov (United States)

Extraintestinal Pathogenic Escherichia coli (ExPEC), including Uropathogenic E. coli (UPEC), are common contaminants in poultry meat, and are a major pathogen associated with inflammatory bowel disease, ulcerative colitis, sepsis, and urinary tract infections. The purpose of this study was to determ...

Complete sequences of IncHI1 plasmids carrying bla_CTX-M-1 and qnrS1 in equine Escherichia coli provide new insights into plasmid evolution

DEFF Research Database (Denmark)

Dolejska, Monika; Villa, Laura; Minoia, Marco

2014-01-01

OBJECTIVES: To determine the structure of two multidrug-resistant IncHI1 plasmids carrying blaCTX-M-1 in Escherichia coli isolates disseminated in an equine clinic in the Czech Republic. METHODS: A complete nucleotide sequencing of 239 kb IncHI1 (pEQ1) and 287 kb IncHI1/X1 (pEQ2) plasmids was per...... highlight the structure and evolution of IncHI1 from equine E. coli. A plasmid-mediated sugar metabolic element could play a key role in strain fitness, contributing to the successful dissemination and maintenance of these plasmids in the intestinal microflora of horses....

(ESBL) producing Escherichia coli and Klebsiella pneumoniae

African Journals Online (AJOL)

Emerging antibiotic resistance due to extended spectrum β-lactamase (ESBL) production limited the use of β-lactam antibiotics against Escherichia coli and Klebsiella pneumoniae. This observational study was conducted at the Microbiology department of the Children's Hospital, Lahore Pakistan, from June, 2009 to ...

Antibiotic resistance properties of uropathogenic Escherichia coli ...

African Journals Online (AJOL)

Purpose: To investigate the antibiotic resistance pattern of uropathogenic Escherichia coli (UPEC) strains isolated from pregnant women with history of recurrent urinary tract infections (RUTIs) and healthy pregnant women. Methods: A total of 485 high vaginal swab specimens were collected from pregnant women with ...

Diarrheagenic Escherichia coli and acute and persistent diarrhea in returned travelers

NARCIS (Netherlands)

Schultsz, C.; van den Ende, J.; Cobelens, F.; Vervoort, T.; van Gompel, A.; Wetsteyn, J. C.; Dankert, J.

2000-01-01

To determine the role of diarrheagenic Escherichia coli in acute and persistent diarrhea in returned travelers, a case control study was performed. Enterotoxigenic E. coli (ETEC) was detected in stool samples from 18 (10.7%) of 169 patients and 4 (3.7%) of 108 controls. Enteroaggregative E. coli

Hydrogen production by recombinant Escherichia coli strains

Science.gov (United States)

Maeda, Toshinari; Sanchez‐Torres, Viviana; Wood, Thomas K.

2012-01-01

Summary The production of hydrogen via microbial biotechnology is an active field of research. Given its ease of manipulation, the best‐studied bacterium Escherichia coli has become a workhorse for enhanced hydrogen production through metabolic engineering, heterologous gene expression, adaptive evolution, and protein engineering. Herein, the utility of E. coli strains to produce hydrogen, via native hydrogenases or heterologous ones, is reviewed. In addition, potential strategies for increasing hydrogen production are outlined and whole‐cell systems and cell‐free systems are compared. PMID:21895995

Identification and characterization of mcr mediated colistin resistance in extraintestinal Escherichia coli from poultry and livestock in China.

Science.gov (United States)

Yassin, Afrah Kamal; Zhang, Jilei; Wang, Jiawei; Chen, Li; Kelly, Patrick; Butaye, Patrick; Lu, Guangwu; Gong, Jiansen; Li, Min; Wei, Lanjing; Wang, Yaoyao; Qi, Kezong; Han, Xiangan; Price, Stuart; Hathcock, Terri; Wang, Chengming

2017-12-29

Antimicrobial resistance to colistin has emerged worldwide threatening the efficacy of one of the last-resort antimicrobials used for the treatment of multidrug-resistant Enterobacteriaceae infection in humans. In this study, we investigated the presence of colistin resistance genes (mcr-1, mcr-2, mcr-3) in Escherichia coli strains isolated from poultry and livestock collected between 2004 and 2012 in China. Furthermore, we studied the maintenance and transfer of the mcr-1 gene in E. coli after serial passages. Overall, 2.7% (17/624) of the E. coli isolates were positive for the mcr-1 gene while none were positive for the mcr-2 and mcr-3 genes. The prevalences of mcr-1 were similar in E. coli isolates from chickens (3.2%; 13/404), pigs (0.9%; 1/113) and ducks (6.8%; 3/44) but were absent in isolates from cattle (0/63). The mcr-1 gene was maintained in the E. coli after six passages (equivalent to 60 generations). In vitro transfer of mcr-1 was evident even without colistin selection. Our data indicate the presence of mcr-1 in extraintestinal E. coli from food-producing animals in China, and suggest that high numbers of the mcr-1-positive bacteria in poultry and livestock do not appear to be readily lost after withdrawal of colistin as a food additive. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Prevalence of Antibiotic Resistance in Escherichia coli Isolated from Poultry Meat Supply in Isfahan

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Farhad Safarpordehkordi

2014-08-01

Conclusions: Despite the high contamination rate of chicken meat with Escherichia coli, majority of isolates had high resistance to common antibiotics. Complete cooking of meat and avoid indiscriminate prescribing of antibiotics, preventing the occurrence of food poisoning due to resistant Escherichia coli.

Difference in melting profiles of gamma irradiated DNA from chicken erythrocytes and from Escherichia coli B/r

International Nuclear Information System (INIS)

Kopff, J.; Miller, G.; Leyko, W.

1977-01-01

Effects of gamma irradiation on melting curves of DNA from chicken erythrocytes and Escherichia coli B/r were compared. Considerable changes, following gamma irradiation in the case of chicken erythrocytes DNA and no changes in the case of DNA from Escherichia coli B/r were observed. To explain the lack of changes in gamma irradiated samples of DNA from Escherichia coli B/r it was assumed that the original effects of irradiation were obscured by the process of renaturation of DNA. To exclude the above mentioned effect, examination of gamma irradiated DNA from Escherichia coli B/r was carried out with the addition of formaldehyde immediately after irradiation of the sample. Using this procedure changes of melting profiles of DNA from Escherichia coli B/r were demonstrated. (author)

Expression of green fluorescent protein (GFPuv) in Escherichia coli ...

African Journals Online (AJOL)

Administrator

The recombinant green fluorescent protein (GFPuv) was expressed by transformed cells of Escherichia coli DH5-α grown in LB/amp broth at 37oC, for 8 h and 24 h. To evaluate the effectiveness of different parameters to improve the expression of GFPuv by E. coli, four variable culturing conditions were set up for assays by ...

Optimization of plasmid electrotransformation into Escherichia coli ...

African Journals Online (AJOL)

In order to improve electroporation, optical density of bacteria, recovery time and electrical parameter (field strength and capacitance) were optimized using the Taguchi statistical method. ANOVA of obtained data indicated that the optimal conditions of electrotransformation of pET-28a (+) plasmid into Escherichia coli ...

Feeding of waste milk to Holstein calves affects antimicrobial resistance of Escherichia coli and Pasteurella multocida isolated from fecal and nasal swabs.

Science.gov (United States)

Maynou, G; Bach, A; Terré, M

2017-04-01

The use of milk containing antimicrobial residues in calf feeding programs has been shown to select for resistant fecal Escherichia coli in dairy calves. However, information is scarce about the effects of feeding calves waste milk (WM) on the prevalence of multidrug-resistant bacteria. The objective of this study was to determine the antimicrobial resistance patterns of fecal E. coli and nasal Pasteurella multocida isolates from calves fed either milk replacer (MR) or WM in 8 commercial dairy farms (4 farms per feeding program). Fecal and nasal swabs were collected from 20 ± 5 dairy calves at 42 ± 3.2 d of age, and from 10 of these at approximately 1 yr of age in each study farm to isolate the targeted bacteria. Furthermore, resistance of E. coli isolates from calf-environment and from 5 calves at birth and their dams was also evaluated in each study farm. Resistances were tested against the following antimicrobial agents: amoxicillin-clavulanic acid, ceftiofur, colistin, doxycycline (DO), enrofloxacin (ENR), erythromycin, florfenicol, imipenem, and streptomycin. A greater number of fecal E. coli resistant to ENR, florfenicol, and streptomycin and more multidrug-resistant E. coli phenotypes were isolated in feces of calves fed WM than in those fed MR. However, the prevalence of fecal-resistant E. coli was also influenced by calf age, as it increased from birth to 6 wk of age for ENR and DO and decreased from 6 wk to 1 yr of age for DO regardless of the feeding program. From nasal samples, an increase in the prevalence of colistin-resistant P. multocida was observed in calves fed WM compared with those fed MR. The resistance patterns of E. coli isolates from calves and their dams tended to differ, whereas similar resistance profiles among E. coli isolates from farm environment and calves were observed. The findings of this study suggest that feeding calves WM fosters the presence of resistant bacteria in the lower gut and respiratory tracts of dairy calves

Hemolytic Porcine Intestinal Escherichia coli without Virulence-Associated Genes Typical of Intestinal Pathogenic E. coli ▿ †

Science.gov (United States)

Schierack, Peter; Weinreich, Joerg; Ewers, Christa; Tachu, Babila; Nicholson, Bryon; Barth, Stefanie

2011-01-01

Testing 1,666 fecal or intestinal samples from healthy and diarrheic pigs, we obtained hemolytic Escherichia coli isolates from 593 samples. Focusing on hemolytic E. coli isolates without virulence-associated genes (VAGs) typical for enteropathogens, we found that such isolates carried a broad variety of VAGs typical for extraintestinal pathogenic E. coli. PMID:21965399

PERFIL DE SENSIBILIDADE MICROBIANA IN VITRO DE LINHAGENS PATOGÊNICAS DE Escherichia coli ISOLADAS DE CARNE BOVINA

Directory of Open Access Journals (Sweden)

Samira Pirola Santos Mantilla

2012-06-01

Full Text Available This study aimed to analyze the antimicrobial resistance of Escherichia coli strains (EPEC A, EPEC B, EPEC C, EIEC A e EIEC B isolated from bovine meat. The antimicrobial susceptibility test was evaluated using the technique described by the National Committee for Clinical Laboratory Standards. The strains were resistant to most antibiotics tested, and gentamicin showed the best efficiency, with 84.9% of the strains showing sensitivity. In addition, cefoxitin was the least effective antimicrobial agent, have a higher percentage of resistant strains. The multidrug resistance to antimicrobials is a finding of great importance to public health, as resistant pathogens may be conveyed to consumers by the ingestion of animal products, making difficult the treatment of bacterial infections and increasing the occurrence of bacteria resistant to antibiotics.

Environmental Escherichia coli: Ecology and public health implications - A review

Science.gov (United States)

Jang, Jeonghwan; Hur, Hor-Gil; Sadowsky, Michael J.; Byappanahalli, Muruleedhara; Yan, Tao; Ishii, Satoshi

2017-01-01

Escherichia coli is classified as a rod-shaped, Gram-negative bacterium in the family Enterobacteriaceae. The bacterium mainly inhabits the lower intestinal tract of warm-blooded animals, including humans, and is often discharged into the environment through feces or wastewater effluent. The presence of E. coli in environmental waters has long been considered as an indicator of recent fecal pollution. However, numerous recent studies have reported that some specific strains of E. coli can survive for long periods of time, and potentially reproduce, in extra-intestinal environments. This indicates that E. coli can be integrated into indigenous microbial communities in the environment. This naturalization phenomenon calls into question the reliability of E. coli as a fecal indicator bacterium (FIB). Recently, many studies reported that E. coli populations in the environment are affected by ambient environmental conditions affecting their long-term survival. Large-scale studies of population genetics provide the diversity and complexity of E. coli strains in various environments, affected by multiple environmental factors. This review examines the current knowledge on the ecology of E. coli strains in various environments in regards to its role as a FIB and as a naturalized member of indigenous microbial communities. Special emphasis is given on the growth of pathogenic E. coli in the environment, and the population genetics of environmental members of the genus Escherichia. The impact of environmental E. coli on water quality and public health is also discussed.

FimH-mediated autoaggregation of Escherichia coli

DEFF Research Database (Denmark)

Schembri, Mark; Christiansen, G.; Klemm, Per

2001-01-01

Autoaggregation is a phenomenon thought to contribute to colonization of mammalian hosts by pathogenic bacteria. Type 1 fimbriae are surface organelles of Escherichia coli that mediate D-mannose-sensitive binding to various host surfaces. This binding is conferred by the minor fimbrial component...... FimH. In this study, we have used random mutagenesis to identify variants of the FimH adhesin that confer the ability of E. coli to autoaggregate and settle from liquid cultures. Three separate autoaggregating clones were identified, all of which contained multiple amino acid changes located within...

Inhibition of Escherichia Coli, Salmonella and Staphylococcus ...

African Journals Online (AJOL)

Escherichia coli O157:H7, Salmonella typhimurium and Staphylococcus. aureus are of great concern to the food industry, especially in foods stored under refrigerated conditions where, unlike most food-borne pathogens are able to multiply. This investigation was conducted to study the inhibitory effect of some spice ...

Prevalence of Arcobacter, Escherichia coli, Staphylococcus aureus ...

African Journals Online (AJOL)

In this study, varying level of resistance of Escherichia coli 66(84.6%), Salmonella 6(100%) and Arcobacter 57(100%) to amoxicillin was observed. The susceptibility pattern indicates that the bacterial isolates exhibited a varying level of resistance to two or more antimicrobial agents with maximum resistance to amoxicillin.

Leaner and meaner genomes in Escherichia coli

DEFF Research Database (Denmark)

Ussery, David

2006-01-01

A 'better' Escherichia coli K-12 genome has recently been engineered in which about 15% of the genome has been removed by planned deletions. Comparison with related bacterial genomes that have undergone a natural reduction in size suggests that there is plenty of scope for yet more deletions....

Multidrug resistance Escherichia coli in pig's farm from Argentina

OpenAIRE

Moredo, Fabiana; Colello, R.; Sanz, Marcelo E.; Cappuccio, Javier A.; Carriquiriborde, Martín; Etcheverría, A.; Perfumo, Carlos J.; Padola, Nora Lía; Leotta, Gerardo Aníbal

2013-01-01

Los objetivos del presente trabajo fueron: i) monitorear la resistencia de E. coli frente a diversos antimicrobianos frecuentemente utilizados con fines terapéuticos y profilácticos en explotaciones porcinas; ii) aislar y caracterizar fenotípica y genotípicamente E. coli toxigénicos provenientes de cerdos con diarrea pre y posdestete; iii) determinar la presencia de integrones clase 1 y 2 como posible mecanismo de diseminación de resistencia. Se procesaron 216 hisopados rectales de cerdos clí...

Profiling of Escherichia coli Chromosome database.

Science.gov (United States)

Yamazaki, Yukiko; Niki, Hironori; Kato, Jun-ichi

2008-01-01

The Profiling of Escherichia coli Chromosome (PEC) database (http://www.shigen.nig.ac.jp/ecoli/pec/) is designed to allow E. coli researchers to efficiently access information from functional genomics studies. The database contains two principal types of data: gene essentiality and a large collection of E. coli genetic research resources. The essentiality data are based on data compilation from published single-gene essentiality studies and on cell growth studies of large-deletion mutants. Using the circular and linear viewers for both whole genomes and the minimal genome, users can not only gain an overview of the genome structure but also retrieve information on contigs, gene products, mutants, deletions, and so forth. In particular, genome-wide exhaustive mutants are an essential resource for studying E. coli gene functions. Although the genomic database was constructed independently from the genetic resources database, users may seamlessly access both types of data. In addition to these data, the PEC database also provides a summary of homologous genes of other bacterial genomes and of protein structure information, with a comprehensive interface. The PEC is thus a convenient and useful platform for contemporary E. coli researchers.

Adsorption of Escherichia coli Using Bone Char | Rezaee | Journal ...

African Journals Online (AJOL)

The aim of study was providing a novel adsorbent for the removal of Escherichia coli (E.coli) as a microbial model from contaminated air especially in hospital units using bone char (BC). The BC was prepared from cattle animal bone by pyrolysis in a furnace at 450°C for 2 h. The characteristics of BC have been determined ...

In vitro susceptibility to mecillinam of Escherichia coli strains isolated from the urine of pregnant women.

Science.gov (United States)

Duployez, C; Loiez, C; Cattoen, C; Descamps, D; Wallet, F; Vachée, A

2016-12-01

Pivmecillinam is a safe beta-lactam for use in pregnancy. It has been widely used for the treatment of lower urinary tract infections (UTIs) in the Nordic countries where its efficacy, minor impact on the microbiota, and low level of resistance among the Escherichia coli strains have been proven. However, susceptibility data related to E. coli involved in asymptomatic bacteriuria and lower UTIs in pregnant women is lacking. We aimed to support the 2015 recommendations issued by the French Infectious Diseases Society (SPILF) on gestational UTI, with a particular focus on pivmecillinam. Antimicrobial susceptibility testing was performed by 12 hospitals with a maternity department on 235 E. coli strains isolated from the urine of pregnant women. Susceptibility to mecillinam was tested by disk diffusion method using the 2015 recommendations of the antibiogram committee of the French microbiology society (CA-SFM). Global susceptibility to mecillinam was 86.4%. Susceptibility to mecillinam was 96.5% for strains susceptible to amoxicillin-clavulanic acid and 38.7% for resistant strains. All six extended-spectrum beta-lactamase-producing E. coli strains were susceptible to mecillinam. Given the efficacy and safety of pivmecillinam during pregnancy, it may be used for the documented treatment of asymptomatic bacteriuria and acute cystitis in pregnant women. It also represents an alternative for the treatment of multidrug-resistant bacterial infections. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Large IncHI2-plasmids encode extended-spectrum β-lactamases (ESBLs) in Enterobacter spp. bloodstream isolates, and support ESBL-transfer to Escherichia coli.

Science.gov (United States)

Nilsen, E; Haldorsen, B C; Sundsfjord, A; Simonsen, G S; Ingebretsen, A; Naseer, U; Samuelsen, O

2013-11-01

We investigated the prevalence of extended-spectrum β-lactamases (ESBLs) in Enterobacter spp. bloodstream isolates from 19 hospital laboratories in Norway during 2011. A total of 62/230 (27%) isolates were resistant to third-generation cephalosporins and four (1.7%) were ESBL-positive; blaCTX -M-15 (n = 3) and blaSHV -12 (n = 1). This is comparable to the prevalence of ESBLs in clinical isolates of Escherichia coli and Klebsiella pneumoniae in Norway during the same period. All ESBL-positive isolates were multidrug resistant (MDR) and harboured plasmid-mediated quinolone resistance. Three isolates supported transfer of large IncHI2-plasmids harbouring ESBL- and MDR-encoding genes to E. coli recipients by in vitro conjugation. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

prevalence of escherichia coli 0157:h7 in fresh and roasted beef

African Journals Online (AJOL)

DR. AMINU

The prevalence of Enterohemorrhagic Escherichia coli 0157:H7 in 300 fresh beef and 150 roasted beef samples from ... likely cause of E. coli O157:H7 infection is undercooked ground beef. ..... coli O157:H7 in a sheep model. Appl. Environ.

Cloning of the nptII gene of Escherichia coli and construction of a recombinant strain harboring functional recA and nptII antibiotic resistance.

Science.gov (United States)

Ghanem, S

2011-01-01

In an attempt to clone the ORF of the nptII gene of Escherichia coli K12 (ATCC 10798), two degenerate primers were designed based on the nptII sequence of its Tn5 transposon. The nptII ORF was placed under the control of the E. coli hybrid trc promoter, in the pKK388-1 vector, transformed into E. coli DH5α ΔrecA (recombinant, deficient strain). Transferred cells were tested for ampicillin, tetracycline, kanamycin, neomycin, geneticin, paromomycin, penicillin, and UV resistance. The neomycin phosphotransferase gene of E. coli was cloned successfully and conferred kanamycin, neomycin, geneticin, and paromomycin resistance to recombinant DH5α; this did not inhibit insertion of additional antibiotic resistance against ampicillin and tetracycline, meaning the trc promoter can express two different genes carried by two different plasmids harbored in the same cell. This resistance conferral process could be considered as an emulation of horizontal gene transfer occurring in nature and would be a useful tool for understanding mechanisms of evolution of multidrug-resistant strains.

Escherichia coli enteroagregativa como agente provocador de diarreia persistente: modelo experimental utilizando microscopia óptica de luz Escherichia coli enteroagregativa como agente provocador de diarrea persistente: modelo experimental utilizando microscopia óptica de luz Enteroaggregative Escherichia coli as a cause of persistent diarrhea: an experimental model using light microscopy

Directory of Open Access Journals (Sweden)

Jacy Alves B. de Andrade

2011-03-01

Full Text Available OBJETIVO: Avaliar interações de amostras de Escherichia coli enteroagregativa com tecido intestinal humano, a fim de documentar potenciais alterações em diferentes regiões do trato digestivo. MÉTODOS: Amostras de Escherichia coli enteroagregativa isoladas das fezes de crianças com diarreia persistente e a amostra protótipo 042, isolada de uma criança com diarreia em Lima, no Peru (controle positivo, foram analisadas por microscopia óptica de luz após semeadura em cultura de orgão in vitro de fragmentos de mucosa ileal e colônica. Foram analisadas as interações entre as diferentes cepas de Escherichia coli enteroagregativa e as mucosas ileal e colônica. RESULTADOS: A análise por microscopia óptica de luz indicou associação destes micro-organismos com o epitélio, provocando alterações. As cepas estudadas aderiram a ambas as regiões avaliadas (intestino delgado distal e grosso e causaram alterações, especialmente naquelas áreas onde interagiram diretamente com o epitélio. No íleo, algumas regiões mostraram internalização secundária. CONCLUSÕES: Esses agentes podem causar diarreia persistente por meio de alterações no intestino delgado, no qual ocorrem as funções digestivo-absortivas. As lesões inflamatórias descritas na mucosa colônica poderiam explicar a colite mostrada em algumas crianças infectadas por Escherichia coli enteroagregativa.OBJETIVO: Evaluar interacciones de muestras de Escherichia coli enteroagregativa (EAEC con tejido intestinal humano, a fin de documentar potenciales alteraciones en distintas regiones del tracto digestivo (intestino delgado distal e intestino grueso y definir, con eso, su rol en la persistencia del proceso diarreico. MÉTODOS: Muestras de EAEC aislada de las heces de niños con diarrea persistente y la muestra prototipo 042, aislada de un niño con diarrea en Lima, Perú (control positivo fueron analizadas por microscopía óptica de luz (ML después de siembra en cultura

Investigation of antimicrobial resistance in Escherichia coli and enterococci isolated from Tibetan pigs.

Directory of Open Access Journals (Sweden)

Peng Li

Full Text Available OBJECTIVES: This study investigated the antimicrobial resistance of Escherichia coli and enterococci isolated from free-ranging Tibetan pigs in Tibet, China, and analyzed the influence of free-ranging husbandry on antimicrobial resistance. METHODS: A total of 232 fecal samples were collected from Tibetan pigs, and the disk diffusion method was used to examine their antimicrobial resistance. Broth microdilution and agar dilution methods were used to determine minimum inhibitory concentrations for antimicrobial agents for which disks were not commercially available. RESULTS: A total of 129 E. coli isolates and 84 Enterococcus isolates were recovered from the fecal samples. All E. coli isolates were susceptible to amoxicillin/clavulanic acid, and 40.4% were resistant to tetracycline. A small number of isolates were resistant to florfenicol (27.9%, ampicillin (27.9%, sulfamethoxazole/trimethoprim (19.4%, nalidixic acid (19.4%, streptomycin (16.2% and ceftiofur (10.9%, and very low resistance rates to ciprofloxacin (7.8%, gentamicin (6.9%, and spectinomycin (2.3% were observed in E. coli. All Enterococcus isolates, including E. faecium, E. faecalis, E. hirae, and E. mundtii, were susceptible to amoxicillin/clavulanic acid and vancomycin, but showed high frequencies of resistance to oxacillin (92.8%, clindamycin (82.1%, tetracycline (64.3%, and erythromycin (48.8%. Resistance rates to florfenicol (17.9%, penicillin (6.0%, ciprofloxacin (3.6%, levofloxacin (1.2%, and ampicillin (1.2% were low. Only one high-level streptomycin resistant E. faecium isolate and one high-level gentamicin resistant E. faecium isolate were observed. Approximately 20% and 70% of E. coli and Enterococcus isolates, respectively, were defined as multidrug-resistant. CONCLUSIONS: In this study, E. coli and Enterococcus isolated from free-ranging Tibetan pigs showed relatively lower resistance rates than those in other areas of China, where more intensive farming practices are

GLYCOSYLATED YGHJ POLYPEPTIDES FROM ENTEROTOXIGENIC ESCHERICHIA COLI (ETEC)

DEFF Research Database (Denmark)

2017-01-01

The present invention relates to glycosylated YghJ polypeptides from or derived from enterotoxigenic Escherichia coli (ETEC) that are immunogenic. In particular, the present invention relates to compositions or vaccines comprising the polypeptides and their application in immunization, vaccination...

Presence and Antimicrobial Resistance of Escherichia coli in Ready-to-Eat Foods in Shaanxi, China.

Science.gov (United States)

Baloch, Allah Bux; Yang, Hua; Feng, Yuqing; Xi, Meili; Wu, Qian; Yang, Qinhao; Tang, Jingsi; He, Xiangxiang; Xiao, Yingping; Xia, Xiaodong

2017-03-01

The aim of this study was to determine the presence and characteristics of Escherichia coli in ready-to-eat (RTE) foods. A total of 300 RTE foods samples were collected in Shaanxi Province, People's Republic of China: 50 samples of cooked meat, 165 samples of vegetable salad, 50 samples of cold noodles, and 35 samples of salted boiled peanuts. All samples were collected during summer (in July to October) 2011 and 2012 and surveyed for the presence of E. coli . E. coli isolates recovered were classified by phylogenetic typing using a PCR assay. The presence of Shiga toxin genes 1 (stx 1 ) and 2 (stx 2 ) was determined for these E. coli isolates by PCR, and all isolates were analyzed for antimicrobial susceptibility and the presence of class 1 integrons. Overall, 267 (89.0%) RTE food samples were positive for E. coli : 49 cold noodle, 46 cooked meat, 150 salad vegetable, and 22 salted boiled peanut samples. Of the 267 E. coli isolates, 73.0% belong to phylogenetic group A, 12.4% to group B1, 6.4% to group B2, and 8.2% to group D. All isolates were negative for both Shiga toxin genes. Among the isolates, 74.2% were resistant to at least one antimicrobial agent, and 17.6% were resistant to three or more antimicrobial agents. Resistance to ampicillin (75.6% of isolates) and tetracycline (73.1% of isolates) was most frequently detected; 26.2% of E. coli isolates and 68.8% of multidrug-resistant E. coli isolates were positive for class 1 integrons. All isolates were sensitive to amikacin. Our findings indicate that RTE foods in Shaanxi were commonly contaminated with antibiotic-resistant E. coli , which may pose a risk for consumer health and for transmission of antibiotic resistance. Future research is warranted to track the contamination sources and develop appropriate steps that should be taken by government, industry, and retailers to reduce microbial contamination in RTE foods.

Purification and Characterization of Recombinant Vaccinia L1R Protein from Escherichia coli

Science.gov (United States)

2016-08-01

RECOMBINANT VACCINIA L1R PROTEIN FROM ESCHERICHIA COLI 1. INTRODUCTION 1.1 Background Vaccinia virus (VACV) is the active component of the...the preparation of the recombinant VACV L1R protein fragment by denaturing , refolding, and purifying material expressed into inclusion bodies in...PURIFICATION AND CHARACTERIZATION OF RECOMBINANT VACCINIA L1R PROTEIN FROM ESCHERICHIA COLI ECBC-TR-1370

Genes and proteins of Escherichia coli K-12.

Science.gov (United States)

Riley, M

1998-01-01

GenProtEC is a database of Escherichia coli genes and their gene products, classified by type of function and physiological role and with citations to the literature for each. Also present are data on sequence similarities among E.coli proteins, representing groups of paralogous genes, with PAM values, percent identity of amino acids, length of alignment and percent aligned. GenProtEC can be accessed at the URL http://www.mbl.edu/html/ecoli.html

Deuterium incorporation into Escherichia-coli proteins

DEFF Research Database (Denmark)

Lederer, H.; May, R. P.; Kjems, Jørgen

1986-01-01

Neutron small-angle scattering studies of single protein subunits in a protein-DNA complex require the adjustment of the neutron scattering-length densities of protein and DNA, which is attainable by specific deuteration of the protein. The neutron scattering densities of unlabelled DNA and DNA......-dependent RNA polymerase of Escherichia coli match when RNA polymerase is isolated from cells grown in a medium containing 46% D2O and unlabelled glucose as carbon source. Their contrasts vanish simultaneously in a dialysis buffer containing 65% D2O. An expression was evaluated which allows the calculation...... of the degree of deuteration and match point of any E. coli protein from the D2O content of the growth medium, taking the 2H incorporation into RNA polymerase amino acids to be representative for all amino acids in E. coli proteins. The small-angle scattering results, on which the calculation of the degree...

Environmental Escherichia coli: ecology and public health implications-a review.

Science.gov (United States)

Jang, J; Hur, H-G; Sadowsky, M J; Byappanahalli, M N; Yan, T; Ishii, S

2017-09-01

Escherichia coli is classified as a rod-shaped, Gram-negative bacterium in the family Enterobacteriaceae. The bacterium mainly inhabits the lower intestinal tract of warm-blooded animals, including humans, and is often discharged into the environment through faeces or wastewater effluent. The presence of E. coli in environmental waters has long been considered as an indicator of recent faecal pollution. However, numerous recent studies have reported that some specific strains of E. coli can survive for long periods of time, and potentially reproduce, in extraintestinal environments. This indicates that E. coli can be integrated into indigenous microbial communities in the environment. This naturalization phenomenon calls into question the reliability of E. coli as a faecal indicator bacterium (FIB). Recently, many studies reported that E. coli populations in the environment are affected by ambient environmental conditions affecting their long-term survival. Large-scale studies of population genetics revealed the diversity and complexity of E. coli strains in various environments, which are affected by multiple environmental factors. This review examines the current knowledge on the ecology of E. coli strains in various environments with regard to its role as a FIB and as a naturalized member of indigenous microbial communities. Special emphasis is given on the growth of pathogenic E. coli in the environment, and the population genetics of environmental members of the genus Escherichia. The impact of environmental E. coli on water quality and public health is also discussed. © 2017 The Society for Applied Microbiology.

The Prevalence of Enterhaemorrhagic Escherichia Coli in children ...

African Journals Online (AJOL)

EHEC), the pathogenicity of other strains of Escherichia coli and other organisms in children presenting with and without diarrhoea in the hospital. Subjects and Methods: A total of 247 stool samples collected from children aged 1 month to 7 ...

Genetic Transfer of Salmonella typhimurium and Escherichia coli Lipopolysaccharide Antigens to Escherichia coli K-12

Science.gov (United States)

Jones, Randall T.; Koeltzow, Donald E.; Stocker, B. A. D.

1972-01-01

Escherichia coli K-12 ϰ971 was crossed with a smooth Salmonella typhimurium donor, HfrK6, which transfers early the ilv-linked rfa region determining lipopolysaccharide (LPS) core structure. Two ilv+ hybrids differing in their response to the LPS-specific phages FO and C21 were then crossed with S. typhimurium HfrK9, which transfers early the rfb gene cluster determining O repeat unit structure. Most recombinants selected for his+ (near rfb) were agglutinated by Salmonella factor 4 antiserum. Transfer of an F′ factor (FS400) carrying the rfb–his region of S. typhimurium to the same two ilv+ hybrids gave similar results. LPS extracted from two ilv+,his+, factor 4-positive hybrids contained abequose, the immunodominant sugar for factor 4 specificity. By contrast, his+ hybrids obtained from ϰ971 itself by similar HfrK9 and F′FS400 crosses were not agglutinated by factor 4 antiserum, indicating that the parental E. coli ϰ971 does not have the capacity to attach Salmonella O repeat units to its LPS core. It is concluded that the Salmonella rfb genes are expressed only in E. coli ϰ971 hybrids which have also acquired ilv-linked genes (presumably rfa genes affecting core structure or O-translocase ability, or both) from a S. typhimurium donor. When E. coli ϰ971 was crossed with a smooth E. coli donor, Hfr59, of serotype O8, which transfers his early, most his+ recombinants were agglutinated by E. coli O8 antiserum and lysed by the O8-specific phage, Ω8. This suggests that, although the parental E. coli K-12 strain ϰ971 cannot attach Salmonella-specific repeat units to its LPS core, it does have the capacity to attach E. coli O8-specific repeat units. PMID:4559827

Escherichia coli O157:H7 - An Emerging Pathogen in foods of Animal Origin

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Ch. Bindu Kiranmayi

Full Text Available Escherichia coli O157:H7 is an emerging public health concern in most countries of the world. E. coli O157:H7 was known to be a human pathogen for nearly 24 years. EHEC O157 infection is estimated to be the fourth most costly food borne disease in Canada and USA, not counting the cost of possible litigation. E. coli O157:H7 and Salmonella are the leading causes of produce related outbreaks, accounting for 20 and 30% respectively. The authority of the Federal Meat Inspection Act, FSIS (Food Safety and Inspection Service declared Escherichia coli O157:H7, an adulterant in raw ground beef and enforced “zero tolerance” (USDA-FSIS, 17 December 1998. Because of the severity of these illnesses and the apparent low infective dose (less than 10 cells, Escherichia coli O157:H7 is considered one of the most serious of known food borne pathogens. Escherichia coli O157:H7 is mainly pathogenic to human but in cattle and other animals, it did not induce any clinical disease except diarrhea. So, these animals act as carriers to Escherichia coli O157:H7. The majority transmission is through eating of undercooked contaminated ground meat and consumption of raw milk, raw vegetables, fruits contaminated by water, cheese, curd and also through consumption of sprouts, lettuce and juice. The conventional isolation procedure includes growth in enrichment broth like modified EC (E. coli broth or modified tryptic soy broth (mTSB Since the infection primarily occurs via faeco-oral route, the preventive measures include food hygiene measures like proper cooking of meat, consumption of pasteurized milk, washing fruits and vegetables especially those to be eaten raw and drinking chlorine treated water and personnel hygiene measures like washing hands after toilet visits. [Veterinary World 2010; 3(8.000: 382-389

Mechanisms of antibiotic resistance to enrofloxacin in uropathogenic Escherichia coli in dog

Science.gov (United States)

Escherichia coli (E. coli) urinary tract infections (UTIs) are becoming a serious problem both for pets and humans (zoonosis) due to the close contact and to the increasing resistance to antibiotics. Canine E. coli represents a good experimental model useful to study this pathology. Moreover, as des...

Spontaneous Escherichia coli Meningitis Associated with Hemophagocytic Lymphohistiocytosis

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Kuo-Hsuan Chang

2006-01-01

Full Text Available Spontaneous Escherichia coli meningitis has not been previously reported in association with hemophago-cytic lymphohistiocytosis (HLH. A previously healthy 72-year-old woman was admitted due to fever, nuchal rigidity, disturbed consciousness and splenomegaly. Anemia, thrombocytopenia and hyperfer-ritinemia developed on the 8th day of hospitalization. Cultures of cerebrospinal fluid and blood grew E. coli. Abundant macrophages overwhelmed erythrocytes in the bone marrow aspirate, confirming the presence of hemophagocytosis. E. coli meningitis was managed with a 40-day course of antibiotic treatment. However, the severity of anemia and thrombocytopenia progressed despite intensive transfusion therapy. The patient died of HLH on the 60th day of hospitalization.

The antibacterial effect of four mouthwashes against streptococcus mutans and escherichia coli.

Science.gov (United States)

Ghapanchi, Janan; Lavaee, Fatemeh; Moattari, Afagh; Shakib, Mahmood

2015-04-01

To evaluate the antimicrobial properties of several mouthwash concentrations on oral Streptococcus mutans and Escherichia coli. The study was conducted at Shiraz Medicine School in 2011. Serial dilutions of Chlorohexidin, Oral B and Persica and Irsha (2,4,8,16,64,128) were prepared in Muller-Hinton media. Minimum inhibitory concentration was visually determined and defined as the lowest concentration of each oral washing which inhibited > 95% growth reduction compared to the growth control well. Chlorhexidine, Oral B and Irsha mouthwash inhibited Streptococcus mutans even with diluted concentrations. Also, Chlorhexidine and Oral B prohibited Escherichia coli with different potencies. But Persica had no antimicrobial activity against either Escherichia coli or Streptococcus mutans. Chlorhexidine, Irsha, and Oral B mouthwashes can be used for antimicrobial effects, especially on Streptococcus mutans. This chemical activity of mouthwashes is an adjuvant for mechanical removing of plaque. However, the antimicrobial effect of Persicaremains controversial.

Escherichia coli Contamination of Lettuce Grown in Soils Amended with Animal Slurry

DEFF Research Database (Denmark)

Jensen, Annette Nygaard; Storm, Christina; Forslund, Anita

2013-01-01

A pilot study was conducted to assess the transfer of Escherichia coli from animal slurry fertilizer to lettuce, with E. coli serving as an indicator of fecal contamination and as an indicator for potential bacterial enteric pathogens. Animal slurry was applied as fertilizer to three Danish agric...... types between slurry, soil, and lettuce. The frequent finding of fecal-contaminated lettuce indicates that human pathogens such as Salmonella and Campylobacter can be present and represent food safety hazards.......A pilot study was conducted to assess the transfer of Escherichia coli from animal slurry fertilizer to lettuce, with E. coli serving as an indicator of fecal contamination and as an indicator for potential bacterial enteric pathogens. Animal slurry was applied as fertilizer to three Danish....... coli. A relatively higher frequency of E. coli in lettuce compared with the soil samples at harvest suggests environmental sources of fecal contamination, e.g., wildlife. The higher frequency was supported by the finding of 21 different PFGE types among the E. coli isolates, with only a few common PFGE...

MOLECULAR DYNAMICS COMPUTER SIMULATIONS OF MULTIDRUG RND EFFLUX PUMPS

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Paolo Ruggerone

2013-02-01

Full Text Available Over-expression of multidrug efflux pumps of the Resistance Nodulation Division (RND protein super family counts among the main causes for microbial resistance against pharmaceuticals. Understanding the molecular basis of this process is one of the major challenges of modern biomedical research, involving a broad range of experimental and computational techniques. Here we review the current state of RND transporter investigation employing molecular dynamics simulations providing conformational samples of transporter components to obtain insights into the functional mechanism underlying efflux pump-mediated antibiotics resistance in Escherichia coli and Pseudomonas aeruginosa.

Molecular Dynamics Computer Simulations of Multidrug RND Efflux Pumps

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Paolo Ruggerone

2013-02-01

Full Text Available Over-expression of multidrug efflux pumps of the Resistance Nodulation Division (RND protein super family counts among the main causes for microbial resistance against pharmaceuticals. Understanding the molecular basis of this process is one of the major challenges of modern biomedical research, involving a broad range of experimental and computational techniques. Here we review the current state of RND transporter investigation employing molecular dynamics simulations providing conformational samples of transporter components to obtain insights into the functional mechanism underlying efflux pump-mediated antibiotics resistance in Escherichia coli and Pseudomonas aeruginosa.

Characterization of diarrhoeagenic Escherichia coli isolates in Jordanian children.

Science.gov (United States)

Shehabi, Asem A; Bulos, Najawa-Kuri; Hajjaj, Kamal G

2003-01-01

In a prospective study carried out among Jordanian children in Amman, a total of 73/250 (29.2%) stool specimens were positive for 1 or more diarrhoeagenic Escherichia coli strains using a multiplex polymerase chain reaction method. This study indicated that diarrhoeagenic E. coli isolates were found frequently more in stools of children with diarrhoea (34%) than without diarrhoea (23.1%), but without any significant difference (p > 0.05). The predominant diarrhoeagenic E. coli strains associated with diarrhoea were enteropathogenic E. coli (11.3%), followed by enterotoxigenic E. coli (9.8%) and enteroaggrative E. coli (9%), whereas in the control group these were 4.3%, 11.1% and 6%, respectively. Enteroinvasive E. coli strains (2.9%) were found only in stools of children with diarrhoea. This study revealed the absence of enterohaemorrhagic E. coli in both diarrhoeal and control stools, and found that diarrhoeagenic E. coli isolates were highly resistance to tetracycline (55%), co-trimoxazole (60%) and ampicillin (89%), which are commonly used antibiotics in Jordan.

Vanillin production by recombinant strains of Escherichia coli Produção de vanilina por linhagens recombinantes de Escherichia coli

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Attilio Converti

2003-11-01

Full Text Available Vanillin production from ferulate was studied using different recombinant strains of Escherichia coli. To prevent the occurrence of aerobic conditions and then possible product oxidation, tests were performed in Erlenmeyer flasks under mild mixing (150 rpm. Among other transformants, E. coli JM109(pBB1 appeared to be the best vanillin producer, being able to convert no less than 95% of starting ferulate to the product within 1h. This yield decreased down to 72% after 72h, likely because of a non-specific oxidase activity responsible for vanillin oxidation to vanillate.A produção de vanilina a partir de ácido ferúlico foi estudada utilizando-se diferentes linhagens recombinantes de Escherichia coli. Para prevenir a ocorrência de condições de aerobiose e a possível oxidação do produto, os ensaios foram realizados em frascos Erlenmeyer sob agitação moderada (150 rpm. E. coli JM109 (pBBI mostrou-se o melhor produtor de vanilina entre os demais agentes transformantes, sendo capaz de converter 95% do ácido ferúlico inicial em produto após 1h, rendimento este que decresceu para 72% após 72h, provavelmente devido à atividade de uma oxidase não-específica responsável pela oxidação de vanilina a ácido vanílico.

Identification of Genes Important for Growth of Asymptomatic Bacteriuria Escherichia coli in Urine

DEFF Research Database (Denmark)

Vejborg, Rebecca Munk; de Evgrafov, Mari Cristina Rodriguez; Phan, Minh Duy

2012-01-01

Escherichia coli is the most important etiological agent of urinary tract infections (UTIs). Unlike uropathogenic E. coli, which causes symptomatic infections, asymptomatic bacteriuria (ABU) E. coli strains typically lack essential virulence factors and colonize the bladder in the absence...

Prevalence and characterization of Escherichia coli isolated from the Upper Oconee Watershed in Northeast Georgia.

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Sohyun Cho

Full Text Available Surface waters are important sources of water for drinking, industrial, agricultural, and recreational uses; hence, contamination of water by fecal, pathogenic, or antimicrobial resistant (AR bacteria is a major environmental and public health concern. However, very little data is available on prevalence of these bacteria in surface water throughout a watershed. This study aimed to characterize Escherichia coli present in the Upper Oconee Watershed, a mixed-use watershed in Athens, GA, USA for potential pathogenicity and AR. E. coli were enumerated by colony counts, cultured by enrichment and direct plating, and characterized by phylo-groups, diarrheagenic pathotypes, and antimicrobial susceptibility. From the analysis, 99.3% (455/458 of the total samples were positive for E. coli resulting in 496 isolates. E. coli counts were as high as 1.2×104 CFU/100 ml, which is above the United States Environmental Protection Agency (U.S. EPA threshold for recreational water (235 CFU/100 ml based on a one-time measurement. Phylo-groups B2 (31.7%; 157/496 and B1 (30.8%; 153/496 were the most prevalent among the isolates. Enteropathogenic E. coli (EPEC (19/496 and Shiga toxin-producing E. coli (STEC (1/496 were the only diarrheagenic pathotypes detected. AR was observed in 6.9% (34/496 of the isolates, 15 of which were multidrug resistant (MDR; resistance to two or more classes of antimicrobials. Tetracycline resistance was most often detected (76.5%; 26/34, followed by ampicillin (32.4%; 11/34, streptomycin (23.5%; 8/34, sulfisoxazole (23.5%; 8/34, and nalidixic acid (14.7%; 5/34. Results from this study showed that E. coli is prevalent in high levels in the Upper Oconee Watershed, suggesting possible widespread fecal contamination. The presence of pathogenic, AR E. coli in the watershed indicates that environmental water can serve as a reservoir of resistant bacteria that may be transferred to humans through drinking and recreational activities.

Prevalence and characterization of Escherichia coli isolated from the Upper Oconee Watershed in Northeast Georgia.

Science.gov (United States)

Cho, Sohyun; Hiott, Lari M; Barrett, John B; McMillan, Elizabeth A; House, Sandra L; Humayoun, Shaheen B; Adams, Eric S; Jackson, Charlene R; Frye, Jonathan G

2018-01-01

Surface waters are important sources of water for drinking, industrial, agricultural, and recreational uses; hence, contamination of water by fecal, pathogenic, or antimicrobial resistant (AR) bacteria is a major environmental and public health concern. However, very little data is available on prevalence of these bacteria in surface water throughout a watershed. This study aimed to characterize Escherichia coli present in the Upper Oconee Watershed, a mixed-use watershed in Athens, GA, USA for potential pathogenicity and AR. E. coli were enumerated by colony counts, cultured by enrichment and direct plating, and characterized by phylo-groups, diarrheagenic pathotypes, and antimicrobial susceptibility. From the analysis, 99.3% (455/458) of the total samples were positive for E. coli resulting in 496 isolates. E. coli counts were as high as 1.2×104 CFU/100 ml, which is above the United States Environmental Protection Agency (U.S. EPA) threshold for recreational water (235 CFU/100 ml based on a one-time measurement). Phylo-groups B2 (31.7%; 157/496) and B1 (30.8%; 153/496) were the most prevalent among the isolates. Enteropathogenic E. coli (EPEC) (19/496) and Shiga toxin-producing E. coli (STEC) (1/496) were the only diarrheagenic pathotypes detected. AR was observed in 6.9% (34/496) of the isolates, 15 of which were multidrug resistant (MDR; resistance to two or more classes of antimicrobials). Tetracycline resistance was most often detected (76.5%; 26/34), followed by ampicillin (32.4%; 11/34), streptomycin (23.5%; 8/34), sulfisoxazole (23.5%; 8/34), and nalidixic acid (14.7%; 5/34). Results from this study showed that E. coli is prevalent in high levels in the Upper Oconee Watershed, suggesting possible widespread fecal contamination. The presence of pathogenic, AR E. coli in the watershed indicates that environmental water can serve as a reservoir of resistant bacteria that may be transferred to humans through drinking and recreational activities.

Enteroaggregative Escherichia coli in Daycare

DEFF Research Database (Denmark)

Hebbelstrup Jensen, Betina; Stensvold, Christen R.; Struve, Carsten

2016-01-01

Enteroaggregative Escherichia coli (EAEC) has been associated with persistent diarrhea, reduced growth acceleration, and failure to thrive in children living in developing countries and with childhood diarrhea in general in industrialized countries. The clinical implications of an EAEC carrier...... and answered a questionnaire regarding gastrointestinal symptoms and exposures. Exposures included foreign travel, consumption of antibiotics, and contact with a diseased animal. In the capital area of Denmark, a total of 179 children aged 0-6 years were followed in a cohort study, in the period between 2009...

Antibacterial Activities and Possible Modes of Action of Acacia nilotica (L. Del. against Multidrug-Resistant Escherichia coli and Salmonella

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Muhammad Bilal Sadiq

2017-01-01

Full Text Available Medicinal plants are frequently used for the treatment of various infectious diseases. The objective of this study was to evaluate the antibacterial activity and mode of action of Acacia nilotica and the antibiogram patterns of foodborne and clinical strains of Escherichia coli and Salmonella. The mechanism of action of acacia extracts against E. coli and Salmonella was elucidated by observing morphological damages including cell integrity and cell membrane permeability, as well as changes in cell structures and growth patterns in kill-time experiments. The clinical isolates of E. coli and Salmonella were found resistant to more of the tested antibiotics, compared to food isolates. Minimum inhibitory concentration and minimum bactericidal concentration of acacia leaf extracts were in the ranges of 1.56–3.12 mg/mL and 3.12–6.25 mg/mL, respectively, whereas pods and bark extracts showed somewhat higher values of 3.12–6.25 mg/mL and 6.25–12.5 mg/mL, respectively, against all tested pathogens. The release of electrolytes and essential cellular constituents (proteins and nucleic acids indicated that acacia extracts damaged the cellular membrane of the pathogens. These changes corresponded to simultaneous reduction in the growth of viable bacteria. This study indicates that A. nilotica can be a potential source of new antimicrobials, effective against antibiotic-resistant strains of pathogens.

Action of sodium deoxycholate on Escherichia coli

International Nuclear Information System (INIS)

D'Mello, A.; Yotis, W.W.

1987-01-01

Sodium deoxycholate is used in a number of bacteriological media for the isolation and classification of gram-negative bacteria from food and the environment. Initial experiments to study the effect of deoxycholate on the growth parameters of Escherichia coli showed an increase in the lag time constant and generation time and a decrease in the growth rate constant total cell yield of this microorganisms. Cell fractionation studies indicated that sodium deoxycholate at levels used in bacteriological media interferes with the incorporation of [U- 14 C]glucose into the cold-trichloroacetic acid-soluble, ethanol-soluble, and trypsin-soluble cellular fractions of E. coli. Finally, sodium deoxycholate interfered with the flagellation and motility of Proteus mirabilis and E. coli. It would appear then that further improvement of the deoxycholate medium may be in order

Action of sodium deoxycholate on Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

D' Mello, A.; Yotis, W.W.

1987-08-01

Sodium deoxycholate is used in a number of bacteriological media for the isolation and classification of gram-negative bacteria from food and the environment. Initial experiments to study the effect of deoxycholate on the growth parameters of Escherichia coli showed an increase in the lag time constant and generation time and a decrease in the growth rate constant total cell yield of this microorganisms. Cell fractionation studies indicated that sodium deoxycholate at levels used in bacteriological media interferes with the incorporation of (U-/sup 14/C)glucose into the cold-trichloroacetic acid-soluble, ethanol-soluble, and trypsin-soluble cellular fractions of E. coli. Finally, sodium deoxycholate interfered with the flagellation and motility of Proteus mirabilis and E. coli. It would appear then that further improvement of the deoxycholate medium may be in order.

Multidrug resistant enterohaemorrhagic Escherichia coli O157:H7 in ...

African Journals Online (AJOL)

Pigeons are commonly seen around human dwellings and in city centres. The movement of these birds from place to place makes them a veritable vehicle for environmental dissemination of pathogens. Enterohaemorrhagic E. coli (EHEC) O157:H7 can cause severe and sometimes fatal gastroenteritis in humans. This study ...

Biofilm Formation Potential of Heat-Resistant Escherichia coli Dairy Isolates and the Complete Genome of Multidrug-Resistant, Heat-Resistant Strain FAM21845.

Science.gov (United States)

Marti, Roger; Schmid, Michael; Kulli, Sandra; Schneeberger, Kerstin; Naskova, Javorka; Knøchel, Susanne; Ahrens, Christian H; Hummerjohann, Jörg

2017-08-01

We tested the biofilm formation potential of 30 heat-resistant and 6 heat-sensitive Escherichia coli dairy isolates. Production of curli and cellulose, static biofilm formation on polystyrene (PS) and stainless steel surfaces, biofilm formation under dynamic conditions (Bioflux), and initial adhesion rates (IAR) were evaluated. Biofilm formation varied greatly between strains, media, and assays. Our results highlight the importance of the experimental setup in determining biofilm formation under conditions of interest, as correlation between different assays was often not a given. The heat-resistant, multidrug-resistant (MDR) strain FAM21845 showed the strongest biofilm formation on PS and the highest IAR and was the only strain that formed significant biofilms on stainless steel under conditions relevant to the dairy industry, and it was therefore fully sequenced. Its chromosome is 4.9 Mb long, and it harbors a total of five plasmids (147.2, 54.2, 5.8, 2.5, and 1.9 kb). The strain carries a broad range of genes relevant to antimicrobial resistance and biofilm formation, including some on its two large conjugative plasmids, as demonstrated in plate mating assays. IMPORTANCE In biofilms, cells are embedded in an extracellular matrix that protects them from stresses, such as UV radiation, osmotic shock, desiccation, antibiotics, and predation. Biofilm formation is a major bacterial persistence factor of great concern in the clinic and the food industry. Many tested strains formed strong biofilms, and especially strains such as the heat-resistant, MDR strain FAM21845 may pose a serious issue for food production. Strong biofilm formation combined with diverse resistances (some encoded on conjugative plasmids) may allow for increased persistence, coselection, and possible transfer of these resistance factors. Horizontal gene transfer may conceivably occur in the food production setting or the gastrointestinal tract after consumption. Copyright © 2017 Marti et al.

Draft Genome Sequence of Escherichia coli K-12 (ATCC 10798)

OpenAIRE

Dimitrova, Daniela; Engelbrecht, Kathleen C.; Putonti, Catherine; Koenig, David W.; Wolfe, Alan J.

2017-01-01

ABSTRACT Here, we present the draft genome sequence of Escherichia coli ATCC 10798. E.?coli ATCC 10798 is a K-12 strain, one of the most well-studied model microorganisms. The size of the genome was 4,685,496?bp, with a G+C content of 50.70%. This assembly consists of 62 contigs and the F plasmid.

Protein export in bacillus subtilis and escherichia coli

NARCIS (Netherlands)

Dijl, Jan Maarten van

1990-01-01

The export of heterologous proteins in Bacillus subtilis and Escherichia coli is often inefficient. Frequently observed problems are: 1) accumulation of the precursor form of the exported protein in the cytoplasm or in the membrane; 2), inefficient or incorrect processing of the precursor; 3),

Production of caffeoylmalic acid from glucose in engineered Escherichia coli.

Science.gov (United States)

Li, Tianzhen; Zhou, Wei; Bi, Huiping; Zhuang, Yibin; Zhang, Tongcun; Liu, Tao

2018-07-01

To achieve biosynthesis of caffeoylmalic acid from glucose in engineered Escherichia coli. We constructed the biosynthetic pathway of caffeoylmalic acid in E. coli by co-expression of heterologous genes RgTAL, HpaBC, At4CL2 and HCT2. To enhance the production of caffeoylmalic acid, we optimized the tyrosine metabolic pathway of E. coli to increase the supply of the substrate caffeic acid. Consequently, an E. coli-E. coli co-culture system was used for the efficient production of caffeoylmalic acid. The final titer of caffeoylmalic acid reached 570.1 mg/L. Microbial production of caffeoylmalic acid using glucose has application potential. In addition, microbial co-culture is an efficient tool for producing caffeic acid esters.

in vitro effectiveness of commercial bacteriophage cocktails on diverse extended spectrum beta-lactamase (ESBL producing Escherichia coli strains

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Aycan Gundogdu

2016-11-01

Full Text Available The objective of this study is to determine the in vitro susceptibility of Georgian bacteriophage cocktails on multi-drug resistant extended-spectrum β-lactamase producing Escherichia coli (ESBL-EC isolated from patients' blood and urine cultures. 615 E. coli isolates were included in this study. PhP-typing and phylogenetic grouping were used for the typing. Antimicrobial resistance profiles and ESBL production of all isolates were confirmed according to CLSI criteria. The activities of four bacteriophage cocktails (Enko-phage, SES-bacteriophage, Pyo-bacteriophage and Intesti-bacteriophage were determined against 142 ESBL- EC using in vitro spot tests. According to this, Enko-phage were active against 87.3% of the tested strains while that ratio was 81.7% for intesti-bacteriophage, 81.7% for Pyo-bacteriophage and 59.2% for SES-bacteriophage cocktails. Based on the contingency tests, the phage cocktails were observed to be statistically significantly (p<0.001 more effective on ESBL-EC strains belonging to phylogenetic groups D and B2. The employed phage cocktails were found to be affective against all tested resistant types. These results are promising especially for the infections that are caused by multi-drug resistant pathogens that are difficult to treat. As this is a preliminary step to the potential clinical trials to be designed for the country, in vitro confirmation of their success on a multi-drug-resistant ESBL-EC collection should be accepted as an initial action, which is encouraging to consider clinical trials of phage therapy especially in countries which are not introduce phage therapy.

A sustainable route to produce the scytonemin precursor using Escherichia coli

DEFF Research Database (Denmark)

Malla, Sailesh; Sommer, Morten O. A.

2014-01-01

moiety of scytonemin from tryptophan and tyrosine in Escherichia coli. We heterologously expressed the biosynthetic pathway from Nostoc punctiforme and discovered that only three enzymes from N. punctiforme are required for the in vivo production of the monomer moiety of scytonemin in E. coli. We also...

Fluorometric determination of ethidium bromide efflux kinetics in Escherichia coli

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Monteiro Gabriel A

2009-10-01

Full Text Available Abstract Background Efflux pump activity has been associated with multidrug resistance phenotypes in bacteria, compromising the effectiveness of antimicrobial therapy. The development of methods for the early detection and quantification of drug transport across the bacterial cell wall is a tool essential to understand and overcome this type of drug resistance mechanism. This approach was developed to study the transport of the efflux pump substrate ethidium bromide (EtBr across the cell envelope of Escherichia coli K-12 and derivatives, differing in the expression of their efflux systems. Results EtBr transport across the cell envelope of E. coli K-12 and derivatives was analysed by a semi-automated fluorometric method. Accumulation and efflux of EtBr was studied under limiting energy supply (absence of glucose and low temperature and in the presence and absence of the efflux pump inhibitor, chlorpromazine. The bulk fluorescence variations were also observed by single-cell flow cytometry analysis, revealing that once inside the cells, leakage of EtBr does not occur and that efflux is mediated by active transport. The importance of AcrAB-TolC, the main efflux system of E. coli, in the extrusion of EtBr was evidenced by comparing strains with different levels of AcrAB expression. An experimental model was developed to describe the transport kinetics in the three strains. The model integrates passive entry (influx and active efflux of EtBr, and discriminates different degrees of efflux between the studied strains that vary in the activity of their efflux systems, as evident from the calculated efflux rates: = 0.0173 ± 0.0057 min-1; = 0.0106 ± 0.0033 min-1; and = 0.0230 ± 0.0075 min-1. Conclusion The combined use of a semi-automated fluorometric method and an experimental model allowed quantifying EtBr transport in E. coli strains that differ in their overall efflux activity. This methodology can be used for the early detection of differences in

Antimicrobial use and antimicrobial susceptibility in Escherichia coli on small- and medium-scale pig farms in north-eastern Thailand

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G. Ström

2017-07-01

Full Text Available Abstract Background Intensification of livestock production seen in many low- and middle-income countries is often believed to be associated with increased use of antimicrobials, and may hence contribute to the emergence of antimicrobial resistance. The aim of this study was to map antimicrobial use on small- (n = 25 and medium-scale (n = 27 pig farms in north-eastern Thailand, and to compare antimicrobial susceptibility of commensal Escherichia coli isolated from sows on these farms. Methods Information regarding pig husbandry and antimicrobial treatment regimens was obtained by the use of semi-structured questionnaires. Faecal samples were collected from three healthy sows at each farm, and Escherichia coli was cultured and analysed for antimicrobial susceptibility using the broth microdilution method. Multilevel regression models were used to compare antimicrobial susceptibility between isolates from small- and medium-scale farms. Results All farms included in the study administered antimicrobials to their sows. Small-scale farmers most commonly (64% decided themselves when to give antimicrobials and the majority (60% bought the medicines at the local store or pharmacy, whereas farmers on medium-scale farms always discussed antimicrobial treatment with a veterinarian. Medium-scale farms used a greater diversity of antimicrobials than small-scale farms and did also administer antimicrobials in feed to a higher extent. High levels of antimicrobial resistance to several critically important antimicrobials for human medicine (including ciprofloxacin, streptomycin and ampicillin were found in isolates from both small- and medium-scale farms. Resistance levels were significantly (P < 0.05 higher in isolates from medium-scale farms for several of the antimicrobials tested, as well as the level of multidrug-resistance (P = 0.026. Conclusion The routines regarding access and administration of antimicrobials differed between the small- and

Establishing Streptomycin Epidemiological Cut-Off Values for Salmonella and Escherichia coli

DEFF Research Database (Denmark)

Migura, Lourdes Garcia; Sunde, Marianne; Karlsmose, Susanne

2011-01-01

This study was conducted to elucidate the accuracy of the current streptomycin epidemiological cut-off value (ECOFF) for Escherichia coli and Salmonella spp. A total of 236 Salmonella enterica and 208 E. coli isolates exhibiting MICs between 4 and 32 mg/L were selected from 12 countries. Isolates...

TEM-145 and TEM-146 β-lactamases produced by Escherichia coli ...

African Journals Online (AJOL)

GREGO

2007-03-05

Mar 5, 2007 ... Key words: Escherichia coli, plasmid-mediated, TEM β-lactamase. ... Enterobacteriaceae, the most prevalent mechanism of resistance to ... the production of a relatively inhibitor-resistant OXA-type β-lactamase .... and 8.6 as transcripts of the E. coli chromosomal AmpC .... Mode of action and mechanisms of.

Serotyping and Antimicrobial Susceptibility Pattern of Escherichia coli Isolates from Urinary Tract Infections in Pediatric Population in a Tertiary Care Hospital

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Shweta Sharma

2016-01-01

Full Text Available Urinary tract infections (UTIs in pediatric population are associated with high morbidity and long term complications. In recent years, there is increased prevalence of Escherichia coli (E. coli strains producing extended spectrum β-lactamase, Amp C, and Metallo β-lactamase, making the clinical management even more difficult. This study was aimed to detect the serotypes and to determine antimicrobial susceptibility profile of E. coli isolates from urine samples of children <10 yrs old. A total of 75 pure E. coli strains isolated from patients with symptoms of UTI and colony count ≥105 organisms/mL were included in the study. Antibiotic sensitivity pattern showed maximum resistance to nalidixic acid (98.7%, followed by ampicillin (97.3%, amoxi-clavulanate (96%, and fluoroquinolones (92% while most of the isolates were found sensitive to piperacillin-tazobactam (13.3%, nitrofurantoin (5.3%, and meropenem (1.3%. 48% of the strains were ESBL producer (extended spectrum beta lactamase. 44% strains were typable withantisera used in our study and the most common serogroup was O6 (33.3% followed by O1 (15.1% and O15 (15.1%. To conclude, judicious use of antibiotics according to hospital antibiotic policy and infection control measures should be implemented to prevent spread of multidrug resistant organisms.

Multidrug-resistant opportunistic pathogens challenging veterinary infection control.

Science.gov (United States)

Walther, Birgit; Tedin, Karsten; Lübke-Becker, Antina

2017-02-01

Although the problems associated with healthcare-associated infections (HAI) and the emergence of zoonotic and multidrug-resistant pathogens in companion animal (dogs, cats and horses) medicine have been well-known for decades, current progress with respect to practical implementation of infection control programs in veterinary clinics has been limited. Clinical outbreak events reported for methicillin-resistant Staphylooccus aureus (MRSA) and Staphylococcus pseudintermedius (MRSP), extended spectrum beta-lactamase (ESBL)-producing Escherichia coli and multidrug-resistant (MDR) Salmonella Serovars indicate the necessity of infection control strategies for protecting animal patients at risk as well as veterinary personnel. The close bond between humans and their companion animals provides opportunities for exchange of microorganisms, including MDR pathogens. This particular aspect of the "One Health" idea requires more representative surveillance efforts and infection control strategies with respect to animal-species specific characters. Copyright © 2016 Elsevier B.V. All rights reserved.

Reconstitution of active mycobacterial binuclear iron monooxygenase complex in Escherichia coli.

Science.gov (United States)

Furuya, Toshiki; Hayashi, Mika; Kino, Kuniki

2013-10-01

Bacterial binuclear iron monooxygenases play numerous physiological roles in oxidative metabolism. Monooxygenases of this type found in actinomycetes also catalyze various useful reactions and have attracted much attention as oxidation biocatalysts. However, difficulties in expressing these multicomponent monooxygenases in heterologous hosts, particularly in Escherichia coli, have hampered the development of engineered oxidation biocatalysts. Here, we describe a strategy to functionally express the mycobacterial binuclear iron monooxygenase MimABCD in Escherichia coli. Sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of the mimABCD gene expression in E. coli revealed that the oxygenase components MimA and MimC were insoluble. Furthermore, although the reductase MimB was expressed at a low level in the soluble fraction of E. coli cells, a band corresponding to the coupling protein MimD was not evident. This situation rendered the transformed E. coli cells inactive. We found that the following factors are important for functional expression of MimABCD in E. coli: coexpression of the specific chaperonin MimG, which caused MimA and MimC to be soluble in E. coli cells, and the optimization of the mimD nucleotide sequence, which led to efficient expression of this gene product. These two remedies enabled this multicomponent monooxygenase to be actively expressed in E. coli. The strategy described here should be generally applicable to the E. coli expression of other actinomycetous binuclear iron monooxygenases and related enzymes and will accelerate the development of engineered oxidation biocatalysts for industrial processes.

Coating of silicone with mannoside-PAMAM dendrimers to enhance formation of non-pathogenic Escherichia coli biofilms against colonization of uropathogens.

Science.gov (United States)

Zhu, Zhiling; Yu, Fei; Chen, Haoqing; Wang, Jun; Lopez, Analette I; Chen, Quan; Li, Siheng; Long, Yuyu; Darouiche, Rabih O; Hull, Richard A; Zhang, Lijuan; Cai, Chengzhi

2017-12-01

Bacterial interference using non-pathogenic Escherichia coli 83972 is a novel strategy for preventing catheter-associated urinary tract infection (CAUTI). Crucial to the success of this strategy is to establish a high coverage and stable biofilm of the non-pathogenic bacteria on the catheter surface. However, this non-pathogenic strain is sluggish to form biofilms on silicone as the most widely used material for urinary catheters. We have addressed this issue by modifying the silicone catheter surfaces with mannosides that promote the biofilm formation, but the stability of the non-pathogenic biofilms challenged by uropathogens over long-term remains a concern. Herein, we report our study on the stability of the non-pathogenic biofilms grown on propynylphenyl mannoside-modified silicone. The result shows that 94% non-pathogenic bacteria were retained on the modified silicone under >0.5 Pa shear stress. After being challenged by three multidrug-resistant uropathogenic isolates in artificial urine for 11 days, large amounts (>4 × 10 6  CFU cm -2 ) of the non-pathogenic bacteria remained on the surfaces. These non-pathogenic biofilms reduced the colonization of the uropathogens by >3.2-log. In bacterial interference, the non-pathogenic Escherichia coli strains are sluggish to form biofilms on the catheter surfaces, due to rapid removal by urine flow. We have demonstrated a solution to this bottleneck by pre-functionalization of mannosides on the silicone surfaces to promote E. coli biofilm formation. A pre-conjugated high affinity propynylphenyl mannoside ligand tethered to the nanometric amino-terminated poly(amido amine) (PAMAM) dendrimer is used for binding to a major E. coli adhesin FimH. It greatly improves the efficiency for the catheter modification, the non-pathogenic biofilm coverage, as well as the (long-term) stability for prevention of uropathogen infections. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Pulsed-Plasma Disinfection of Water Containing Escherichia coli

Science.gov (United States)

Satoh, Kohki; MacGregor, Scott J.; Anderson, John G.; Woolsey, Gerry A.; Fouracre, R. Anthony

2007-03-01

The disinfection of water containing the microorganism, Escherichia coli (E. coli) by exposure to a pulsed-discharge plasma generated above the water using a multineedle electrode (plasma-exposure treatment), and by sparging the off-gas of the pulsed plasma into the water (off-gas-sparging treatment), is performed in the ambient gases of air, oxygen, and nitrogen. For the off-gas-sparging treatment, bactericidal action is observed only when oxygen is used as the ambient gas, and ozone is found to generate the bactericidal action. For the plasma-exposure treatment, the density of E. coli bacteria decreases exponentially with plasma-exposure time for all the ambient gases. It may be concluded that the main contributors to E. coli inactivation are particle species produced by the pulsed plasma. For the ambient gases of air and nitrogen, the influence of acidification of the water in the system, as a result of pulsed-plasma exposure, may also contribute to the decay of E. coli density.

ANALISIS KANDUNGAN BORAKS DAN Escherichia coli PADA JAJANAN BAKSO SAPI YANG DIPERDAGANGKAN DI KOTA BANJARBARU

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Nur Rahmi

2016-09-01

Full Text Available This study aims to determine how the content of borax and Escherichia coli on meatballs snacks and the factors that affect the food security of meatballs snacks by using Easy Method of Borax Test and Method of Most Probable Number (MPN for Escherichia coli bacteria contamination. This research was conducted in Banjarbaru on 5 villages, and sampling technique used is stratified sampling. The results of the study showed that from 32 samples taken from five village location, it was not identified any borax based on PERMENKES No. 033 of 2012, while for the examination of Escherichia coli, there are 14 samples of meatballs (43.75% which were eligible, and 18 samples of meatballs (56.25% which containEscherichia coli ranges from 3.6 to 62 CFU /g or not meeting the criteria of ISO 7388: 2009. The factor that might not trigger the addition of borax is that the traders have a good knowledge and attitude toward borax which regarded as a toxic substance and can be harmful to health. Factors that cause microbial contamination of Escherichia coli on meatballs snacks is the lack of food hygiene and sanitation in the food processing, cooked food storage, transport, serving, sanitation facilities, and personnel handlers compared with the good supply of foodstuffs and food ingredients storage.

Escherichia coli O104 associated with human diarrhea, South Africa, 2004-2011.

Science.gov (United States)

Tau, Nomsa P; Meidany, Parastu; Smith, Anthony M; Sooka, Arvinda; Keddy, Karen H

2012-08-01

To determine the origin of >4,000 suspected diarrheagenic Escherichia coli strains isolated during 2004-2011 in South Africa, we identified 7 isolates as serotype O104; 5 as enteroaggregative E. coli O104:H4, and 2 as enteropathogenic E. coli O104:non-H4. Pulsed-field gel electrophoresis showed that these isolates were unrelated to the 2011 E. coli O104:H4 outbreak strain from Germany.

The Development of a Portable SPR Bioanalyzer for Sensitive Detection of Escherichia coli O157:H7

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Shun Wang

2016-11-01

Full Text Available The purpose of this study was to develop a portable surface plasmon resonance (SPR bioanalyzer for the sensitive detection of Escherichia coli O157:H7 in comparison with an enzyme-linked immunosorbent assay (ELISA. The experimental setup mainly consisted of an integrated biosensor and a homemade microfluidic cell with a three-way solenoid valve. In order to detect Escherichia coli O157:H7 using the SPR immunoassay, 3-mercaptopropionic acid (3-MPA was chemisorbed onto a gold surface via covalent bond for the immobilization of biological species. 1-ethyl-3-(3-dimethylaminopropyl carbodiimide hydrochloride (EDC and N-hydroxysuccinimide (NHS were used as crosslinker reagents to enable the reaction between 3-MPA and Escherichia coli O157:H7 antibodies by covalent –CO–NH– amide bonding. The experimental results were obtained from the Escherichia coli O157:H7 positive samples prepared by 10-, 20-, 40-, 80-, and 160-fold dilution respectively, which show that a good linear relationship with the correlation coefficient R of 0.982 existed between the response units from the portable SPR bioanalyzer and the concentration of Escherichia coli O157:H7 positive samples. Moreover, the theoretical detection limit of 1.87 × 103 cfu/mL was calculated from the positive control samples. Compared with the Escherichia coli O157:H7 ELISA kit, the sensitivity of this portable SPR bioanalyzer is four orders of magnitude higher than the ELISA kit. The results demonstrate that the portable SPR bioanalyzer could provide an alternative method for the quantitative and sensitive determination of Escherichia coli O157:H7 in field.

Comparative genomics of an IncA/C multidrug resistance plasmid from Escherichia coli and Klebsiella isolates from intensive care unit patients and the utility of whole-genome sequencing in health care settings.

Science.gov (United States)

Hazen, Tracy H; Zhao, LiCheng; Boutin, Mallory A; Stancil, Angela; Robinson, Gwen; Harris, Anthony D; Rasko, David A; Johnson, J Kristie

2014-08-01

The IncA/C plasmids have been implicated for their role in the dissemination of β-lactamases, including gene variants that confer resistance to expanded-spectrum cephalosporins, which are often the treatment of last resort against multidrug-resistant, hospital-associated pathogens. A bla(FOX-5) gene was detected in 14 Escherichia coli and 16 Klebsiella isolates that were cultured from perianal swabs of patients admitted to an intensive care unit (ICU) of the University of Maryland Medical Center (UMMC) in Baltimore, MD, over a span of 3 years. Four of the FOX-encoding isolates were obtained from subsequent samples of patients that were initially negative for an AmpC β-lactamase upon admission to the ICU, suggesting that the AmpC β-lactamase-encoding plasmid was acquired while the patient was in the ICU. The genomes of five E. coli isolates and six Klebsiella isolates containing bla(FOX-5) were selected for sequencing based on their plasmid profiles. An ∼ 167-kb IncA/C plasmid encoding the FOX-5 β-lactamase, a CARB-2 β-lactamase, additional antimicrobial resistance genes, and heavy metal resistance genes was identified. Another FOX-5-encoding IncA/C plasmid that was nearly identical except for a variable region associated with the resistance genes was also identified. To our knowledge, these plasmids represent the first FOX-5-encoding plasmids sequenced. We used comparative genomics to describe the genetic diversity of a plasmid encoding a FOX-5 β-lactamase relative to the whole-genome diversity of 11 E. coli and Klebsiella isolates that carry this plasmid. Our findings demonstrate the utility of whole-genome sequencing for tracking of plasmid and antibiotic resistance gene distribution in health care settings. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Cytokine response to Escherichia coli in gnotobiotic pigs

Czech Academy of Sciences Publication Activity Database

Šplíchal, Igor; Šplíchalová, Alla; Trebichavský, Ilja

2008-01-01

Roč. 53, č. 2 (2008), s. 161-164 ISSN 0015-5632 R&D Projects: GA ČR GA523/05/0249 Institutional research plan: CEZ:AV0Z50200510 Keywords : germ-free pigs * escherichia coli * cytokine response Subject RIV: EE - Microbiology, Virology Impact factor: 1.172, year: 2008

Escherichia coli and virus isolated from ''sticky kits''

DEFF Research Database (Denmark)

Jørgensen, M.; Scheutz, F.; Strandbygaard, Bertel

1996-01-01

A total of 121 Escherichia coli strains isolated from 3-week-old mink kits were serotyped and examined for virulence factors. 56 strains were isolated from healthy kits while 65 were from ''sticky kits''. Among these, 34 different serotypes were detected. No difference in serotypes or the presenc...

TiO2 Photocatalysis Damages Lipids and Proteins in Escherichia coli

NARCIS (Netherlands)

Carre, Gaelle; Hamon, Erwann; Ennahar, Said; Estner, Maxime; Lett, Marie-Claire; Horvatovich, Peter; Gies, Jean-Pierre; Keller, Valerie; Keller, Nicolas; Andre, Philippe

This study investigates the mechanisms of UV-A (315 to 400 nm) photocatalysis with titanium dioxide (TiO2) applied to the degradation of Escherichia coli and their effects on two key cellular components: lipids and proteins. The impact of TiO2 photocatalysis on E. coli survival was monitored by

Genetic and molecular analyses of Escherichia coli N-acetylneuraminate lyase gene.

OpenAIRE

Kawakami, B; Kudo, T; Narahashi, Y; Horikoshi, K

1986-01-01

Two plasmids containing the N-acetylneuraminate lyase (NALase) gene (nanA) of Escherichia coli, pNL1 and pNL4, were constructed. Immunoprecipitation analysis indicated that the 35,000-dalton protein encoded in pNL4 was NALase. The synthesis of NALase in E. coli carrying these plasmids was constitutive.

Multiple Antibiotic Resistance Patterns of Escherichia coli Isolates from Swine Farms

OpenAIRE

Mathew, A. G.; Saxton, A. M.; Upchurch, W. G.; Chattin, S. E.

1999-01-01

Antibiotic resistance of Escherichia coli from sows and pigs was determined to compare patterns between pigs of various ages and degrees of antibiotic use. Resistance patterns differed between farm types and pigs of differing ages, indicating that pig age and degree of antibiotic use affect resistance of fecal E. coli.

Simultaneous virtual prediction of anti-Escherichia coli activities and ADMET profiles: A chemoinformatic complementary approach for high-throughput screening.

Science.gov (United States)

Speck-Planche, Alejandro; Cordeiro, M N D S

2014-02-10

Escherichia coli remains one of the principal pathogens that cause nosocomial infections, medical conditions that are increasingly common in healthcare facilities. E. coli is intrinsically resistant to many antibiotics, and multidrug-resistant strains have emerged recently. Chemoinformatics has been a great ally of experimental methodologies such as high-throughput screening, playing an important role in the discovery of effective antibacterial agents. However, there is no approach that can design safer anti-E. coli agents, because of the multifactorial nature and complexity of bacterial diseases and the lack of desirable ADMET (absorption, distribution, metabolism, elimination, and toxicity) profiles as a major cause of disapproval of drugs. In this work, we introduce the first multitasking model based on quantitative-structure biological effect relationships (mtk-QSBER) for simultaneous virtual prediction of anti-E. coli activities and ADMET properties of drugs and/or chemicals under many experimental conditions. The mtk-QSBER model was developed from a large and heterogeneous data set of more than 37800 cases, exhibiting overall accuracies of >95% in both training and prediction (validation) sets. The utility of our mtk-QSBER model was demonstrated by performing virtual prediction of properties for the investigational drug avarofloxacin (AVX) under 260 different experimental conditions. Results converged with the experimental evidence, confirming the remarkable anti-E. coli activities and safety of AVX. Predictions also showed that our mtk-QSBER model can be a promising computational tool for virtual screening of desirable anti-E. coli agents, and this chemoinformatic approach could be extended to the search for safer drugs with defined pharmacological activities.

Escherichia coli: a brief review of diarrheagenic pathotypes and their role in diarrheal diseases in Iran

Science.gov (United States)

Jafari, A; Aslani, MM; Bouzari, S

2012-01-01

Diarrheagenic Escherichia coli have developed different strategies for establishment of infection in their host. Understanding these pathogenic mechanisms has led to the development of specific diagnostic tools for identification and categorization of E. coli strains into different pathotypes. This review aims to provide an overview of the various categories of diarrheagenic Escherichia coli and the data obtained in Iran pertaining to these pathotypes. PMID:23066484

Effect of bile on growth, peritoneal absorption, and blood clearance of Escherichia coli in E coli peritonitis

International Nuclear Information System (INIS)

Andersson, R.; Schalen, C.; Tranberg, K.G.

1991-01-01

The effect of intraperitoneal bile on growth, peritoneal absorption, and clearance of Escherichia coli was determined in E coli peritonitis in the rat. In E coli peritonitis, intraperitoneal bacterial counts gradually decreased, whereas they increased (after 2 hours) with subsequent development of bacteremia in E coli plus bile peritonitis. After an intraperitoneal injection of labeled bacteria, blood radioactivity was only initially lower in E coli plus bile peritonitis compared with E coli peritonitis. Clearance from blood was lower in E coli plus bile peritonitis than in E coli peritonitis. Organ localization was similar in E coli peritonitis and E coli plus bile peritonitis with decreased splenic, increased pulmonary, and unchanged hepatic uptakes compared with controls. Impaired peritoneal absorption of bacteria, together with impaired local host defense, is likely to enhance the noxious effect of bile in E coli peritonitis

Emergence and mechanism of carbapenem-resistant Escherichia coli in Henan, China, 2014

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Wen-juan Liang

2018-05-01

Full Text Available The emergence and dissemination of carbapenem-resistant Escherichia coli (E. coli strains is a main risk for global public health, but little is known of carbapenemase producing E. coli in Henan, China. The study was undertaken to investigate the prevalence and mechanism of carbapenem-resistant E. coli strains in a hospital in Xinxiang, Henan, China, 2014. A total of 5 carbapenemase-producing E. coli strains were screened from 1014 isolates. We found that they were all resistant to meropenem and imipenem. Amikacin showed the best sensitivity, with gentamicin coming up next. The positive rate of blaNDM was 80% (4/5. The sequencing results showed that two isolates belonged to blaNDM-1 whereas other 2 isolates carried the blaNDM-5. Other carbapenemase genes including blaIMP, blaVIM, blaKPC and blaOXA-48 were not detected. The blaCTX-M-15, blaTEM-1, sul2, aad, and aac(6”–Ib–cr were also detected. MLST analysis showed that NDM-producing E. coli were sporadic. Conjugation test indicated blaNDM could be transferred. In conclusion, the blaNDM was the principal resistance mechanism of carbapenem-resistant E. coli in the hospital, Henan, China. Keywords: blaNDM, Carbapenem-resistant, Escherichia coli

TRIMETHOPRIM-SULFAMETHOXAZOLE RESISTANCE IN SEWAGE ISOLATES OF ESCHERICHIA COLI

Science.gov (United States)

Sewage samples from seven locations in the United States were analyzed for Escherichia coli isolates which were resistant to trimethoprim-sulfamethoxazole (SXT). The prevalence rate of SXT resistant organisms varied between the different geographical locales. The majority of th...

Antibiotic Resistance, RAPD- PCR Typing of Multiple Drug Resistant Strains of Escherichia Coli From Urinary Tract Infection (UTI).

Science.gov (United States)

Marialouis, Xavier Alexander; Santhanam, Amutha

2016-03-01

Global spreading of multidrug resistant strains of Escherichia coli is responsible for Urinary Tract Infection (UTI) which is a major health problem in of concern. Among the gram negative bacteria, the major contributors for UTI belongs to the family Enterobacteriaceae, which includes E. coli, Klebsiella, Citrobacter and Proteus. However, E. coli accounts for the major cause of Urinary tract infections (UTIs) and accounts for 75% to 90% of UTI isolates. The main aim of this study is to analyse the phylogenetic grouping of clinical isolates of UTI E. coli. In this study nearly 58 E. coli strains were isolated and confirmed through microbiological, biochemical characterization. The urine samples were collected from outpatients having symptoms of UTI, irrespective of age and sex in Tamil Nadu, India. The isolates were subjected to analyse for ESBL and AmpC β-lactamase production. To understand its genetic correlation, molecular typing was carried out using RAPD-PCR method. Here we noted phenotypically twenty seven isolates were positive for ESBL and seven for AmpC β-lactamase production. However, among the ESBL isolates higher sensitivity was noted for Nitrofurantoin and Cefoxitin. It is worth to note that the prevalence of UTIs was more common among female and elderly male. Phylogenetic grouping revealed the presence of 24 isolates belonged to B2 group followed by 19 isolates to group A, eight isolates to group B1 and Seven isolates to group D. Phenotypically most of the strains were positive for ESBL and showed high sensitivity for Nitrofurantoin and cefoxitin.

Antibiofilm Effects of Lactobacilli against Ciprofloxacin-Resistant Uropathogenic Escherichia coli strains in Pasteurized Milk

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Mahsa Yeganeh

2017-11-01

Full Text Available  Background and Objective: Uropathogenic Escherichia coli-induced urinary tract infections are the most common uropathogenic Escherichia coli etiological agent. In addition, most of biofilms created by these bacteria can be regarded as a serious problem in the food industry. Foodborne diseases have always been considered an emerging public health concern throughout the world. Many outbreaks have been found to be associated with biofilms. Thus, the aim of the present study is to investigate the anti-adhesive effects of lactic acid bacteria against strains of Ciprofloxacin-Resistant Uropathogenic Escherichia coli using microbial techniques in pasteurized milk.Material and Methods: In this study, strains of Lactobacillus plantarum, Lactobacillus casei and Lactobacillus acidophilus were provided from Pasteur Institute of Iran. Twenty strains of Uropathogenic Escherichia coli-Induced Urinary Tract Infections were isolated from patients with urinary tract infection in Shahid Labbafinejad hospital of Iran. Eight strains with ability of biofilm formation were selected for microbial tests. All of these eight strains were resistant to ciprofloxacin. Disk diffusion method was used to assess the susceptibility of all isolates to the ten common antibiotics. Eight samples of Uropathogenic Escherichia coli were inoculated in pasteurized milk. The microtitre plate 100 method was used to detect anti-adhesive activity of lactobacilli supernatant.Results and Conclusion: Results showed that the eight human isolates were resistant to antibiotics. Isolate of number 4 was the most susceptible strains to antibiofilm effects of lactobacilli in the pasteurized milk. The anti-adhesive effects of lactobacilli on Uropathogenic were confirmed in all microbial tests. In this study, Lactobacillus plantarum revealed the highest inhibitory activity against Uropathogenic Escherichia coli 4 strain with inhibition zones of 42 mm. This strain was reported as a proper probiotic

Escherichia coli can be transformed by a liposome-mediated lipofection method.

Science.gov (United States)

Kawata, Yoshikazu; Yano, Shin-ichi; Kojima, Hiroyuki

2003-05-01

Transformation of Escherichia coli is a basic technique for genetic engineering. We used a liposome-mediated lipofection method to transform electrocompetent E. coli cells which has little natural competence of foreign DNA without electroporation treatment, and got transformants with simple and quick treatment by a plasmid or a transposon and transposase complex.

Tranformasi Fragmen Dna Kromosom Xanthomonas Campestris ke dalam Escherichia Coli

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Wibowo Mangunwardoyo

2002-04-01

Full Text Available Research on DNA transformation of Xanthomonas campestris into Escherichia coli DH5αα using plasmid vector Escherichia coli (pUC19. was carried out. DNA chromosome was isolated using CTAB method, alkali lysis method was used to isolate DNA plasmid. Both of DNA plasmid and chromosome were digested using restriction enzyme EcoRI. Competent cell was prepared with CaCl2 and heat shock method for transformation procedure. The result revealed transformation obtain 5 white colonies, with transformation frequency was 1,22 x 10-8 colony/competent cell. Electrophoresis analysis showed the DNA fragment (insert in range 0.5 – 7,5 kb. Further research should be carried out to prepare the genomic library to obtain better result of transformant.

Draft Genome Sequence of Escherichia coli K-12 (ATCC 10798).

Science.gov (United States)

Dimitrova, Daniela; Engelbrecht, Kathleen C; Putonti, Catherine; Koenig, David W; Wolfe, Alan J

2017-07-06

Here, we present the draft genome sequence of Escherichia coli ATCC 10798. E. coli ATCC 10798 is a K-12 strain, one of the most well-studied model microorganisms. The size of the genome was 4,685,496 bp, with a G+C content of 50.70%. This assembly consists of 62 contigs and the F plasmid. Copyright © 2017 Dimitrova et al.

Antibiotic-resistance of Escherichia coli isolates from stored pig slurry

OpenAIRE

Silva, F.F.P.; Santos, M.; Schmidt, Veronica

2008-01-01

The antimicrobial resistance of 96 Escherichia coli strains isolated from a stabilization pond system on a pig-breeding farm was evaluated. Strains were tested for their resistance against 14 antimicrobial using the agar diffusion method. E. coli strains showed resistance to tetracycline (82.3%), nalidixic acid (64%), ampicilin (41%), sulfamethoxazole/trimethoprin (36%), sulfonamide (34%), cloranphenicol (274%), ciprofloxacin (19%), cefaclor (16%), streptomicyn (7.3%), neomicyn (1%), amoxacil...

Metabolic and Transcriptional Response to Cofactor Perturbations in Escherichia coli

DEFF Research Database (Denmark)

Holm, Anders Koefoed; Blank, L.M.; Oldiges, M.

2010-01-01

Metabolic cofactors such as NADH and ATP play important roles in a large number of cellular reactions, and it is of great interest to dissect the role of these cofactors in different aspects of metabolism. Toward this goal, we overexpressed NADH oxidase and the soluble F1-ATPase in Escherichia coli...... of redox and energy metabolism and should help in developing metabolic engineering strategies in E. coli....

Cephalosporin-resistant Escherichia coli isolated from farm-workers and pigs in northern Vietnam

DEFF Research Database (Denmark)

Dang, Son T T; Bortolaia, Valeria; Thi, Nhat T

2018-01-01

OBJECTIVE Antimicrobial-resistant bacteria may be transmitted between farm workers and livestock. This study aimed to determine and compare the prevalence and the genetic determinants of cefotaxime-resistant and ESBL-producing Escherichia coli in faecal isolates from workers and pigs at 100 farms...... in northern Vietnam. METHODS Farmers were interviewed about antimicrobial usage in livestock. Escherichia coli isolated on MacConkey agar containing 2 mg/L of cefotaxime (CTX) were tested for susceptibility to different cephalosporins by disk diffusion and screened for occurrence of ESBL-encoding genes by PCR......% in pigs. In 76% of farms, CTX-resistant E. coli were shared by pigs and farm workers. ESBL-producing E. coli were detected from pigs and workers at 66 and 69 farms, respectively. The ESBL phenotype was mainly mediated by CTX-M and to a lesser extent by TEM. Occurrence of blaCTX-M was similar in E. coli...

In Vivo Transmission of an IncA/C Plasmid in Escherichia coli Depends on Tetracycline Concentration, and Acquisition of the Plasmid Results in a Variable Cost of Fitness.

Science.gov (United States)

Johnson, Timothy J; Singer, Randall S; Isaacson, Richard E; Danzeisen, Jessica L; Lang, Kevin; Kobluk, Kristi; Rivet, Bernadette; Borewicz, Klaudyna; Frye, Jonathan G; Englen, Mark; Anderson, Janet; Davies, Peter R

2015-05-15

IncA/C plasmids are broad-host-range plasmids enabling multidrug resistance that have emerged worldwide among bacterial pathogens of humans and animals. Although antibiotic usage is suspected to be a driving force in the emergence of such strains, few studies have examined the impact of different types of antibiotic administration on the selection of plasmid-containing multidrug resistant isolates. In this study, chlortetracycline treatment at different concentrations in pig feed was examined for its impact on selection and dissemination of an IncA/C plasmid introduced orally via a commensal Escherichia coli host. Continuous low-dose administration of chlortetracycline at 50 g per ton had no observable impact on the proportions of IncA/C plasmid-containing E. coli from pig feces over the course of 35 days. In contrast, high-dose administration of chlortetracycline at 350 g per ton significantly increased IncA/C plasmid-containing E. coli in pig feces (P IncA/C plasmid to other indigenous E. coli hosts. There was no evidence of conjugal transfer of the IncA/C plasmid to bacterial species other than E. coli. In vitro competition assays demonstrated that bacterial host background substantially impacted the cost of IncA/C plasmid carriage in E. coli and Salmonella. In vitro transfer and selection experiments demonstrated that tetracycline at 32 μg/ml was necessary to enhance IncA/C plasmid conjugative transfer, while subinhibitory concentrations of tetracycline in vitro strongly selected for IncA/C plasmid-containing E. coli. Together, these experiments improve our knowledge on the impact of differing concentrations of tetracycline on the selection of IncA/C-type plasmids. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

ANIMAL ENTEROTOXIGENIC ESCHERICHIA COLI

Science.gov (United States)

Dubreuil, J. Daniel; Isaacson, Richard E.; Schifferli, Dieter M.

2016-01-01

Enterotoxigenic Escherichia coli (ETEC) is the most common cause of E. coli diarrhea in farm animals. ETEC are characterized by the ability to produce two types of virulence factors; adhesins that promote binding to specific enterocyte receptors for intestinal colonization and enterotoxins responsible for fluid secretion. The best-characterized adhesins are expressed in the context of fimbriae, such as the F4 (also designated K88), F5 (K99), F6 (987P), F17 and F18 fimbriae. Once established in the animal small intestine, ETEC produces enterotoxin(s) that lead to diarrhea. The enterotoxins belong to two major classes; heat-labile toxin that consist of one active and five binding subunits (LT), and heat-stable toxins that are small polypeptides (STa, STb, and EAST1). This chapter describes the disease and pathogenesis of animal ETEC, the corresponding virulence genes and protein products of these bacteria, their regulation and targets in animal hosts, as well as mechanisms of action. Furthermore, vaccines, inhibitors, probiotics and the identification of potential new targets identified by genomics are presented in the context of animal ETEC. PMID:27735786

Presence of multi-drug resistant pathogenic Escherichia coli in the San Pedro River located in the State of Aguascalientes, Mexico.

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Flor Yazmin Ramirez Castillo

2013-06-01

Full Text Available Contamination of surface waters in developing countries is a great concern. Treated and untreated wastewaters have been discharged into rivers and streams, leading to possible waterborne infection outbreaks and may represent a significant dissemination mechanism of antibiotic resistance genes. In this study, the water quality of San Pedro River, the main river and pluvial collector of the Aguascalientes State, Mexico was assessed. Thirty sample locations were tested throughout the River. The main physicochemical parameters of water were evaluated. Results showed high levels of fecal pollution as well as inorganic and organic matter abundant enough to support the heterotrophic growth of microorganisms. These results indicate poor water quality in samples from different locations. One hundred and fifty Escherichia coli were collected and screened by PCR for several virulence genes. Isolates were classified as either pathogenic (n = 91 or commensal (n = 59. The disc diffusion method was used to determine antimicrobial susceptibility to 13 antibiotics. Fifty-two percent of the isolates were resistant to at least one antimicrobial agent and 30.6% were multi-resistant. Eighteen E. coli strains were quinolone resistant of which 16 were multi-resistant. Plasmid-mediated quinolone resistance genes were detected in 12 isolates. Mutations at the Ser-83→Leu and/or Asp-87→Asn in the gyrA gene were detected as well as mutations at the Ser-80→Ile in parC. An E. coli microarray (Maxivirulence V 3.1 was used to characterize the virulence and antimicrobial resistance genes profiles of the fluoroquinolone-resistant isolates. Antimicrobial resistance genes such as blaTEM, sulI, sulII, dhfrIX, aph3 (strA and tet (B as well as integrons were found in fluoroquinolone resistance E. coli strains. The presence of potential pathogenic E. coli and antibiotic resistance in San Pedro River such as fluoroquinolone resistant E. coli could pose a potential threat to human

In vitro antimicrobial activity of five essential oils on multi-drug resistant Gram-negative clinical isolates

OpenAIRE

Hercules Sakkas; Panagiota Gousia; Vangelis Economou; Vassilios Sakkas; Stefanos Petsios; Chrissanthy Papadopoulou

2016-01-01

Aim/Background: The emergence of drug-resistant pathogens has drawn attention on medicinal plants for potential antimicrobial properties. The objective of the present study was the investigation of the antimicrobial activity of five plant essential oils on multidrug resistant Gram-negative bacteria. Materials and Methods: Basil, chamomile blue, origanum, thyme, and tea tree oil were tested against clinical isolates of Acinetobacter baumannii (n = 6), Escherichia coli (n = 4), Klebsiella pneum...

Attaching and effacing Escherichia coli isolates from Danish children: clinical significance and microbiological characteristics

DEFF Research Database (Denmark)

Jensen, C; Ethelberg, S; Olesen, B

2007-01-01

This study describes the prevalence, clinical manifestations and microbiological characteristics of attaching and effacing Escherichia coli isolates, i.e., enteropathogenic E. coli (EPEC) belonging to the classical EPEC serotypes, non-EPEC attaching and effacing E. coli (A/EEC) and verocytotoxin...

Anti-Escherichia coli effect of Hibiscus sabdariffa L. in a meat model

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Marcelo Pinto PAIM

Full Text Available Abstract Hibiscus sabdariffa L. is used in traditional medicine because of its bioactive properties, such as antioxidant and antibacterial. Escherichia coli is a Gram-negative bacteria and as an indicator of contamination in food. The aim of this work was to evaluate the anti-Escherichia coli effect and the change in pH on the control of aerobic mesophilic microorganisms, using hydroethanolic extract of H. sabdariffa L. in different concentrations in a meat model, verifying its potential as food additive for microbiological stability on ground beef during cooling storage. For the preparation of the treatments, the meat experimental units were elaborated with different concentrations of the vegetal extract (5, 10, 15 and 20%, ground beef and contaminated with E. coli. For pH evaluation, the meat experimental units were added different percentages of hydroethanolic extract. The H. sabdariffa L. antibacterial action reduced two logarithmic levels in practically all treatments. The best pH result was obtained in the meat containing 30% of the extract. The hydroethanolic extracts of Hibiscus sabdariffa L. showed anti-Escherichia coli activity in the presence of refrigerated ground beef. Analyzing the pH results and the count of aerobic mesophilic bacteria, it is possible this extract to be used as a natural food additive.

Prodigiosin - A Multifaceted Escherichia coli Antimicrobial Agent.

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Tjaša Danevčič

Full Text Available Despite a considerable interest in prodigiosin, the mechanism of its antibacterial activity is still poorly understood. In this work, Escherichia coli cells were treated with prodigiosin to determine its antimicrobial effect on bacterial physiology. The effect of prodigiosin was concentration dependent. In prodigiosin treated cells above MIC value no significant DNA damage or cytoplasmic membrane disintegration was observed. The outer membrane, however, becomes leaky. Cells had severely decreased respiration activity. In prodigiosin treated cells protein and RNA synthesis were inhibited, cells were elongated but could not divide. Pre-treatment with prodigiosin improved E. coli survival rate in media containing ampicillin, kanamycin and erythromycin but not phleomycin. The results suggest that prodigiosin acts as a bacteriostatic agent in E. coli cells. If prodigiosin was diluted, cells resumed growth. The results indicate that prodigiosin has distinct mode of antibacterial action in different bacteria.

Viabilidad de Escherichia coli en presencia de diferentes contaminantes

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Antonio Rivera T

2006-04-01

Full Text Available La contaminación en ríos condiciona la presencia de microorganismos adaptados al ecosistema entre ellos a patógenos de importancia en salud pública. Objetivo: Determinar la viabilidad de Escherichia coli en presencia de nitrato de plata, carbonato de amonio, fenol y formaldehído. Materiales y métodos: Se tomaron muestras de agua del río Alseseca, que luego se sembró en medios de cultivo selectivos para enterobacterias, seleccionándose las colonias del género Escherichia, las cuales fueron sembradas en el medio de orientación CHROMagar ECC. Las muestras de E. coli se evaluaron en presencia de nitrato de plata, carbonato de amonio, fenol y formaldehído. Resultados: El grupo experimental presentó viabilidad en presencia de los cuatro compuestos, el grupo control positivo presentó nula viabilidad, la comparación entre los grupos mostró diferencia significativa (p< 0,05. Conclusión: Los aislamientos de E. coli mostraron viabilidad, implicando riesgos para el ecosistemas y la salud, ya que el río Alseseca atraviesa por el municipio de Puebla donde existen núcleos poblacionales importantes.

in Escherichia coli with native cholesterol oxidase expressed

African Journals Online (AJOL)

The structure and bio-activity of an endogenous cholesterol oxidase from Brevibacterium sp. was compared to the same enzyme exogenously expressed in Escherichia coli BL21 (DE3) with and without N- or C-terminal his-tags. The different proteins were purified with affinity and subtractive protocols. The specific activity of ...

Transport proteins promoting Escherichia coli pathogenesis

Science.gov (United States)

Tang, Fengyi; Saier, Milton H.

2014-01-01

Escherichia coli is a genetically diverse species infecting hundreds of millions of people worldwide annually. We examined seven well-characterized E. coli pathogens causing urinary tract infections, gastroenteritis, pyelonephritis and haemorrhagic colitis. Their transport proteins were identified and compared with each other and a non-pathogenic E. coli K12 strain to identify transport proteins related to pathogenesis. Each pathogen possesses a unique set of protein secretion systems for export to the cell surface or for injecting effector proteins into host cells. Pathogens have increased numbers of iron siderophore receptors and ABC iron uptake transporters, but the numbers and types of low-affinity secondary iron carriers were uniform in all strains. The presence of outer membrane iron complex receptors and high-affinity ABC iron uptake systems correlated, suggesting co-evolution. Each pathovar encodes a different set of pore-forming toxins and virulence-related outer membrane proteins lacking in K12. Intracellular pathogens proved to have a characteristically distinctive set of nutrient uptake porters, different from those of extracellular pathogens. The results presented in this report provide information about transport systems relevant to various types of E. coli pathogenesis that can be exploited in future basic and applied studies. PMID:24747185

Transport proteins promoting Escherichia coli pathogenesis.

Science.gov (United States)

Tang, Fengyi; Saier, Milton H

2014-01-01

Escherichia coli is a genetically diverse species infecting hundreds of millions of people worldwide annually. We examined seven well-characterized E. coli pathogens causing urinary tract infections, gastroenteritis, pyelonephritis and haemorrhagic colitis. Their transport proteins were identified and compared with each other and a non-pathogenic E. coli K12 strain to identify transport proteins related to pathogenesis. Each pathogen possesses a unique set of protein secretion systems for export to the cell surface or for injecting effector proteins into host cells. Pathogens have increased numbers of iron siderophore receptors and ABC iron uptake transporters, but the numbers and types of low-affinity secondary iron carriers were uniform in all strains. The presence of outer membrane iron complex receptors and high-affinity ABC iron uptake systems correlated, suggesting co-evolution. Each pathovar encodes a different set of pore-forming toxins and virulence-related outer membrane proteins lacking in K12. Intracellular pathogens proved to have a characteristically distinctive set of nutrient uptake porters, different from those of extracellular pathogens. The results presented in this report provide information about transport systems relevant to various types of E. coli pathogenesis that can be exploited in future basic and applied studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

HUBUNGAN PERSONAL HYGIENE DENGAN KEBERADAAN ESCHERICHIA COLI PADA MAKANAN DI TEMPAT PENGOLAHAN MAKANAN (TPM BUFFER AREA BANDARA ADI SOEMARMO SURAKARTA

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Fitka Romanda

2017-01-01

Full Text Available Keberadaan Escherichia coli dalam sumber air atau makanan merupakan indikasi pasti terjadinya  kontaminasi tinja manusia. Kontaminasi ini dapat berdampak pada Kejadian Luar Biasa keracunan makanan di negara berkembang, termasuk di Indonesia. Adanya kontaminasi Escherichia coli pada makanan dapat disebabkan faktor personal hygiene penjamah makanan yang kurang baik. Penelitian ini bertujuan untuk mengetahui adanya hubungan personal hygiene penjamah makanan dengan Escherichia coli. Penelitian ini menggunakan metode observasional dengan pendekatan cross sectional. Subyek penelitian adalah 65 penjamah makanan dan 65 sampel makanan di 22 tempat pengolahan makanan buffer area Bandara Adi Soemarmo Surakarta. Hasil penelitian menunjukan adanya hubungan personal hygiene dengan keberadaan Escherichia coli pada makanan di Tempat Pengolahan Makanan Buffer Area Bandara Adi Soemarmo Surakarta dengan uji statistik dengan Chi Square didapatkan p value (0,000 dan kekuatan hubungan sedang dengan nilai C (0,477. Berdasarkan hasil penelitian, disimpulkan terdapat hubungan personal hygiene penjamah makanan dengan keberadaan Escherichia coli pada makanan di tempat pengolahan makanan (TPM buffer area Bandara Adi Soemarmo Surakarta.   Kata kunci. Personal Hygiene, Escherichia coli, Buffer Area

Genome Sequences of Two Copper-Resistant Escherichia coli Strains Isolated from Copper-Fed Pigs

DEFF Research Database (Denmark)

Lüthje, Freja L.; Hasman, Henrik; Aarestrup, Frank Møller

2014-01-01

The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances.......The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances....

Molecular epidemiology of extended-spectrum β-lactamase-producing Escherichia coli in the community and hospital in Korea: emergence of ST131 producing CTX-M-15

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Park Sun

2012-06-01

Full Text Available Abstract Background The prevalence of extended-spectrum β-lactamase (ESBL-producing Escherichia coli has been increased not only in the hospital but also in the community worldwide. This study was aimed to characterize ESBL- producing E. coli isolates and to investigate the molecular epidemiology of community isolates in comparison with hospital isolates at a single center in Korea. Methods A total of 142 ESBL-producing E. coli isolates were collected at Daejeon St Mary’s Hospital in Korea from January 2008 to September 2009. The ESBLs were characterized by PCR sequencing using specific primers. The genetic relatedness was determined by pulsed field gel electrophoresis (PFGE and multilocus sequence typing (MLST. Results Of 142 isolates, 139 were positive for CTX-M type ESBLs; CTX-M-14 (n = 69, 49.6 %, CTX-M-15 (n = 53, 38.1 % and both CTX-M-14 and -15 (n = 17, 12.2 %. CTX-M-14 and CTX-M-15 were detected in both community and hospital isolates whereas isolates producing both CTX-M14 and-15 were mainly identified in the hospital. CTX-M producing E. coli isolates were genetically heterogeneous, revealing 75 distinct PFGE types. By MLST, 21 distinctive STs including 5 major STs (ST131, ST405, ST38, ST10, and ST648 were identified. Major STs were distributed in both community and hospital isolates, and ST131 was the predominant clone regardless of the locations of acquisition. No specific major STs were confined to a single type of ESBLs. However, ST131 clones were significantly associated with CTX-M-15 and the majority of them were multidrug-resistant. Distinctively, we identified a hospital epidemic caused by the dissemination of an epidemic strain, ST131-PFGE type 10, characterized by multidrug resistance and co-producing both CTX-Ms with OXA-1 or TEM-1b. Conclusions The epidemiology of ESBL-producing E. coli is a complex and evolving phenomenon attributed to the horizontal transfer of genetic elements and clonal spread of

Biomolecular Mechanisms of Pseudomonas aeruginosa and Escherichia coli Biofilm Formation

Science.gov (United States)

Laverty, Garry; Gorman, Sean P.; Gilmore, Brendan F.

2014-01-01

Pseudomonas aeruginosa and Escherichia coli are the most prevalent Gram-negative biofilm forming medical device associated pathogens, particularly with respect to catheter associated urinary tract infections. In a similar manner to Gram-positive bacteria, Gram-negative biofilm formation is fundamentally determined by a series of steps outlined more fully in this review, namely adhesion, cellular aggregation, and the production of an extracellular polymeric matrix. More specifically this review will explore the biosynthesis and role of pili and flagella in Gram-negative adhesion and accumulation on surfaces in Pseudomonas aeruginosa and Escherichia coli. The process of biofilm maturation is compared and contrasted in both species, namely the production of the exopolysaccharides via the polysaccharide synthesis locus (Psl), pellicle Formation (Pel) and alginic acid synthesis in Pseudomonas aeruginosa, and UDP-4-amino-4-deoxy-l-arabinose and colonic acid synthesis in Escherichia coli. An emphasis is placed on the importance of the LuxR homologue sdiA; the luxS/autoinducer-II; an autoinducer-III/epinephrine/norepinephrine and indole mediated Quorum sensing systems in enabling Gram-negative bacteria to adapt to their environments. The majority of Gram-negative biofilms consist of polysaccharides of a simple sugar structure (either homo- or heteropolysaccharides) that provide an optimum environment for the survival and maturation of bacteria, allowing them to display increased resistance to antibiotics and predation. PMID:25438014

Biomolecular Mechanisms of Pseudomonas aeruginosa and Escherichia coli Biofilm Formation

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Garry Laverty

2014-07-01

Full Text Available Pseudomonas aeruginosa and Escherichia coli are the most prevalent Gram-negative biofilm forming medical device associated pathogens, particularly with respect to catheter associated urinary tract infections. In a similar manner to Gram-positive bacteria, Gram-negative biofilm formation is fundamentally determined by a series of steps outlined more fully in this review, namely adhesion, cellular aggregation, and the production of an extracellular polymeric matrix. More specifically this review will explore the biosynthesis and role of pili and flagella in Gram-negative adhesion and accumulation on surfaces in Pseudomonas aeruginosa and Escherichia coli. The process of biofilm maturation is compared and contrasted in both species, namely the production of the exopolysaccharides via the polysaccharide synthesis locus (Psl, pellicle Formation (Pel and alginic acid synthesis in Pseudomonas aeruginosa, and UDP-4-amino-4-deoxy-l-arabinose and colonic acid synthesis in Escherichia coli. An emphasis is placed on the importance of the LuxR homologue sdiA; the luxS/autoinducer-II; an autoinducer-III/epinephrine/norepinephrine and indole mediated Quorum sensing systems in enabling Gram-negative bacteria to adapt to their environments. The majority of Gram-negative biofilms consist of polysaccharides of a simple sugar structure (either homo- or heteropolysaccharides that provide an optimum environment for the survival and maturation of bacteria, allowing them to display increased resistance to antibiotics and predation.

Incidence and antimicrobial susceptibility of Escherichia coli O157:H7 isolates recovered from dairy farms in Amathole District Municipality, Eastern Cape, South Africa

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Asive Myataza

2017-11-01

Full Text Available Objective: To assess the incidence of Escherichia coli (E. coli O157:H7 in water and cattle rectal samples from three commercial dairy farms in Amathole District Municipalities in the Eastern Cape Province of South Africa. Methods: Samples were collected bimonthly from cattle rectum and dairy water sources including irrigation water, drinking water troughs and wastewater between June and November 2014. Standard culture-based methods were applied for the microbial analyses, the disc diffusion method was employed for the antibiotic susceptibility test and PCR approach was utilized for identification of the isolates. Results: A total of 252 presumptive E. coli O157:H7 were isolated and subjected to molecular confirmation by PCR. About 18.7% (47/252 of these were confirmed as E. coli O157:H7. The antimicrobial susceptibility profile of these confirmed isolates revealed high-level resistance against penicillin G (81%, tetracycline (43%, oxytetracycline (62%, erythromycin (68%, sulphamethoxazole (57%, chloramphenicol (55%, doxycycline (51% and trimethoprimsulphamethoxazole (45%. Conclusions: This is the first report of multi-drug resistance E. coli O157:H7 in commercial dairy farms in the province and suggests the possibility of same in other provinces of the country, and this is the subject of the intensive investigation in our group.

Effect of visible range electromagnetic radiations on Escherichia coli ...

African Journals Online (AJOL)

Background: Escherichia coli is the agent responsible for a range of clinical diseases. With emerging antimicrobial resistance, other treatment options including solar/photo-therapy are becoming increasingly common. Visible Range Radiation Therapy/Colour Therapy is an emerging technique in the field of ...

Expression and purification of recombinant hemoglobin in Escherichia coli

DEFF Research Database (Denmark)

Natarajan, Chandrasekhar; Jiang, Xiaoben; Fago, Angela

2011-01-01

BACKGROUND: Recombinant DNA technologies have played a pivotal role in the elucidation of structure-function relationships in hemoglobin (Hb) and other globin proteins. Here we describe the development of a plasmid expression system to synthesize recombinant Hbs in Escherichia coli, and we describe...

Inactivation of Escherichia coli by titanium dioxide photocatalytic oxidation.

Science.gov (United States)

Titanium dioxide in the anatase crystalline form was used as a photocatalyst to generate hydroxyl radicals in a flowthrough water reactor. Experiments were performed on pure cultures of Escherichia coli in dechlorinated tap water and a surface water sample to evaluate the disinfe...

In vitro antibacterial activity of methanol and water extracts of adiantum capillus veneris and tagetes patula against multidrug resistant bacterial strains

International Nuclear Information System (INIS)

Hussain, M.M.; Ahmad, B.; Bashid, E.; Hashim, S.

2014-01-01

The aim of present study was to screen the antimicrobial activities of extracts of leaves and stems of Adiantum capillus veneris and Tagetes patula against multidrug-resistant (MDR) bacterial strains. Extracts from the leaves and stems of these plants were extracted with methanol and water and tested for their antibacterial activity by disc diffusion method against ten MDR bacterial strains i.e., Citrobacter freundii, Escherichia coli, Providencia, Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae, Proteus vulgaris, Salmonella typhi, Shigella and Vibrio cholerae. Leaves methanol extract (LME) of Adiantum showed maximum Zone of Inhibition (ZI) against Providencia, Klebsiella pneumoniae, Shigella, Vibrio cholerae, Staphylococcus aureus, Proteus vulgaris and Salmonella typhi, whereas its stem methanol extract (SME) was very active against Escherichia coli, Klebsiella pneumoniae and Salmonella typhi. Similarly LME of Tagetes showed highest ZI against Escherichia coli and Vibrio cholerae while SME showed highest ZI to Escherichia coli, Vibrio cholerae, Providencia, Shigella and Klebsiella pneumoniae. Leaves water extract (LWE) of Adiantum was very active against all ten bacterial strains while its stem water extract (SWE) showed maximum ZI against Escherichia coli, Klebsiella pneumoniae and Salmonella typhi, Shigella, Proteus vulgaris and Providencia. LWE of Tagetes was only active against Vibrio cholerae whereas SWE was very active against Salmonella typhi and active against P. vulgaris, Citrobacter freundii and Vibrio cholerae. It was concluded from this study that extracts of both Adiantum and Tagetes have prominent activities against most of the MDR bacterial strains and needs further studies for utmost benefits. (author)

Characterization of putative multidrug resistance transporters of the major facilitator-superfamily expressed in Salmonella Typhi

DEFF Research Database (Denmark)

Shaheen, Aqsa; Ismat, Fouzia; Iqbal, Mazhar

2015-01-01

Multidrug resistance mediated by efflux pumps is a well-known phenomenon in infectious bacteria. Although much work has been carried out to characterize multidrug efflux pumps in Gram-negative and Gram-positive bacteria, such information is still lacking for many deadly pathogens. The aim...... of this study was to gain insight into the substrate specificity of previously uncharacterized transporters of Salmonella Typhi to identify their role in the development of multidrug resistance. S. Typhi genes encoding putative members of the major facilitator superfamily were cloned and expressed in the drug......-hypersensitive Escherichia coli strain KAM42, and tested for transport of 25 antibacterial compounds, including representative antibiotics of various classes, antiseptics, dyes and detergents. Of the 15 tested putative transporters, STY0901, STY2458 and STY4874 exhibited a drug-resistance phenotype. Among these, STY4874...

Effect of enrofloxacin treatment on plasma endotoxin during bovine Escherichia coli mastitis

NARCIS (Netherlands)

Dosogne, H.; Meyer, E.; Sturk, A.; van Loon, J.; Massart-Leën, A. M.; Burvenich, C.

2002-01-01

OBJECTIVE AND DESIGN: To investigate the effect of enrofloxacin on endotoxin resorption during bovine Escherichia coli mastitis. ANIMALS: 12 healthy early post partum Holstein cows. TREATMENT: Mastitis was induced by intramammary infusion of 10(4) cfu E. coli P4:032. Six cows were treated twice

Urothelial CD44 facilitates Escherichia coli infection of the murine urinary tract

NARCIS (Netherlands)

Rouschop, Kasper M. A.; Sylva, Marc; Teske, Gwendoline J. D.; Hoedemaeker, Inge; Pals, Steven T.; Weening, Jan J.; van der Poll, Tom; Florquin, Sandrine

2006-01-01

Escherichia coli is the most common pathogen found in urinary tract infections (UTIs), mainly affecting children and women. We report that CD44, a hyaluronic acid (HA) binding protein that mediates cell-cell and cell-matrix interactions, facilitates the interaction of E. coli with urothelial cells

Sos - response induction by gamma radiation in Escherichia coli strains with different repair capacities

International Nuclear Information System (INIS)

Serment Guerrero, J.H.

1992-01-01

The Sos - response in Escherichia coli is formed by several genes involved in mechanisms of tolerance and/or repair, and only activates when a DNA - damage appears. It is controlled by recA and lexA genes. In normal circumstances, LexA protein is linked in every Sos operators, blocking the transcription. When a DNA damage occurs, a Sos signal is generated, Rec A protein changes its normal functions, starts acting as a protease and cleaves Lex A, allowing the transcription of all Sos genes. This response can be quantified by means of Sos Chromo test, performed by Quillardet and Ofnung (1985). In using the Chromo test, it has been observed that the DNA damage made by gamma radiation in Escherichia coli depends on both the doses and the doses rate. It has been shown that the exposure of Escherichia coli PQ37 strain (uvrA) to low doses at low dose rate appears to retard the response, suggesting the action of a repair mechanism. (Brena 1990). In this work, we compare the response in Escherichia coli strains deficient in different mechanisms of repair and/or tolerance. It is observed the importance of rec N gene in the repair of DNA damage produced by gamma radiation. (Author)

An engineered non-oxidative glycolysis pathway for acetone production in Escherichia coli.

Science.gov (United States)

Yang, Xiaoyan; Yuan, Qianqian; Zheng, Yangyang; Ma, Hongwu; Chen, Tao; Zhao, Xueming

2016-08-01

To find new metabolic engineering strategies to improve the yield of acetone in Escherichia coli. Results of flux balance analysis from a modified Escherichia coli genome-scale metabolic network suggested that the introduction of a non-oxidative glycolysis (NOG) pathway would improve the theoretical acetone yield from 1 to 1.5 mol acetone/mol glucose. By inserting the fxpk gene encoding phosphoketolase from Bifidobacterium adolescentis into the genome, we constructed a NOG pathway in E.coli. The resulting strain produced 47 mM acetone from glucose under aerobic conditions in shake-flasks. The yield of acetone was improved from 0.38 to 0.47 mol acetone/mol glucose which is a significant over the parent strain. Guided by computational analysis of metabolic networks, we introduced a NOG pathway into E. coli and increased the yield of acetone, which demonstrates the importance of modeling analysis for the novel metabolic engineering strategies.

Inactivation of Escherichia coli in soil by solarization

International Nuclear Information System (INIS)

Wu, S.; Nishihara, M.; Kawasaki, Y.; Yokoyama, A.; Matsuura, K.; Koga, T.; Ueno, D.; Inoue, K.; Someya, T.

2009-01-01

Contamination of agricultural soil by fecal pathogenic bacteria poses a potential risk of infection to humans. For the biosafety control of field soil, soil solarization in an upland field was examined to determine the efficiency of solarization on the inactivation of Escherichia coli inoculated into soil as a model microorganism for human pathogenic bacteria. Soil solarization, carried out by sprinkling water and covering the soil surface with thin plastic sheets, greatly increased the soil temperature. The daily average temperature of the solarized soil was 4–10°C higher than that of the non-solarized soil and fluctuated between 31 and 38°C. The daily highest temperature reached more than 40°C for 8 days in total in the solarized soil during the second and third weeks of the experiment. Escherichia coli in the solarized soil became undetectable (< 0.08 c.f.u. g −1 dry soil) within 4 weeks as a result, whereas E. coli survived for more than 6 weeks in the non-solarized soil. Soil solarization, however, had little influence on the total direct count and total viable count of bacteria in the soil. These results indicate that soil solarization would be useful for the biosafety control of soil contaminated by human pathogens via immature compost or animal feces. (author)

Effect of methylglyoxal on multidrug-resistant Pseudomonas aeruginosa

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Katsuhiko eHayashi

2014-04-01

Full Text Available Honey has a complex chemistry, and its broad-spectrum antimicrobial activity varies with floral source, climate, and harvesting conditions. Methylglyoxal was identified as the dominant antibacterial component of manuka honey. Although it has been known that methylglyoxal has antibacterial activity against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus, there is not much information describing its activity against gram-negative bacteria. In this study, we report the effect of methylglyoxal against multidrug-resistant Pseudomonas aeruginosa (MDRP using 53 clinically isolated strains. We also assessed the effect of deleting the five multidrug efflux systems in P. aeruginosa, as well as the efflux systems in Escherichia coli and Salmonella enterica serovar Typhimurium, on MICs of methylglyoxal. Our results indicate that methylglyoxal inhibits the growth of MDRP at concentrations of 128–512 µg/ml (1.7–7.1 mM and is not recognized by drug efflux systems.

Development of a Web Tool for Escherichia coli Subtyping Based on fimH Alleles.

Science.gov (United States)

Roer, Louise; Tchesnokova, Veronika; Allesøe, Rosa; Muradova, Mariya; Chattopadhyay, Sujay; Ahrenfeldt, Johanne; Thomsen, Martin C F; Lund, Ole; Hansen, Frank; Hammerum, Anette M; Sokurenko, Evgeni; Hasman, Henrik

2017-08-01

The aim of this study was to construct a valid publicly available method for in silico fimH subtyping of Escherichia coli particularly suitable for differentiation of fine-resolution subgroups within clonal groups defined by standard multilocus sequence typing (MLST). FimTyper was constructed as a FASTA database containing all currently known fimH alleles. The software source code is publicly available at https://bitbucket.org/genomicepidemiology/fimtyper, the database is freely available at https://bitbucket.org/genomicepidemiology/fimtyper_db, and a service implementing the software is available at https://cge.cbs.dtu.dk/services/FimTyper FimTyper was validated on three data sets: one containing Sanger sequences of fimH alleles of 42 E. coli isolates generated prior to the current study (data set 1), one containing whole-genome sequence (WGS) data of 243 third-generation-cephalosporin-resistant E. coli isolates (data set 2), and one containing a randomly chosen subset of 40 E. coli isolates from data set 2 that were subjected to conventional fimH subtyping (data set 3). The combination of the three data sets enabled an evaluation and comparison of FimTyper on both Sanger sequences and WGS data. FimTyper correctly predicted all 42 fimH subtypes from the Sanger sequences from data set 1 and successfully analyzed all 243 draft genomes from data set 2. FimTyper subtyping of the Sanger sequences and WGS data from data set 3 were in complete agreement. Additionally, fimH subtyping was evaluated on a phylogenetic network of 122 sequence type 131 (ST131) E. coli isolates. There was perfect concordance between the typology and fimH -based subclones within ST131, with accurate identification of the pandemic multidrug-resistant clonal subgroup ST131- H 30. FimTyper provides a standardized tool, as a rapid alternative to conventional fimH subtyping, highly suitable for surveillance and outbreak detection. Copyright © 2017 American Society for Microbiology.

The asymptomatic bacteriuria Escherichia coli strain 83972 outcompetes uropathogenic E. coli strains in human urine

DEFF Research Database (Denmark)

Hancock, Viktoria; Ulett, G.C.; Schembri, M.A.

2006-01-01

Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU). In contrast to uropathogenic E. coli (UPEC), which causes symptomatic urinary tract infections (UTI), very little is known about the mechanisms by which these strains colonize the human urinary tract....... The prototype ABU E. coli strain 83972 was originally isolated from a girl who had carried it asymptomatically for 3 years. Deliberate colonization of UTI-susceptible individuals with E. coli 83972 has been used successfully as an alternative approach for the treatment of patients who are refractory...... to conventional therapy. Colonization with strain 83972 appears to prevent infection with UPEC strains in such patients despite the fact that this strain is unable to express the primary adhesins involved in UTI, viz. P and type 1 fimbriae. Here we investigated the growth characteristics of E. coli 83972 in human...

Multidrug Efflux Pumps from Enterobacteriaceae, Vibrio cholerae and Staphylococcus aureus Bacterial Food Pathogens

Directory of Open Access Journals (Sweden)

Jody L. Andersen

2015-01-01

Full Text Available Foodborne illnesses caused by bacterial microorganisms are common worldwide and constitute a serious public health concern. In particular, microorganisms belonging to the Enterobacteriaceae and Vibrionaceae families of Gram-negative bacteria, and to the Staphylococcus genus of Gram-positive bacteria are important causative agents of food poisoning and infection in the gastrointestinal tract of humans. Recently, variants of these bacteria have developed resistance to medically important chemotherapeutic agents. Multidrug resistant Escherichia coli, Salmonella enterica, Vibrio cholerae, Enterobacter spp., and Staphylococcus aureus are becoming increasingly recalcitrant to clinical treatment in human patients. Of the various bacterial resistance mechanisms against antimicrobial agents, multidrug efflux pumps comprise a major cause of multiple drug resistance. These multidrug efflux pump systems reside in the biological membrane of the bacteria and actively extrude antimicrobial agents from bacterial cells. This review article summarizes the evolution of these bacterial drug efflux pump systems from a molecular biological standpoint and provides a framework for future work aimed at reducing the conditions that foster dissemination of these multidrug resistant causative agents through human populations.

Multidrug Efflux Pumps from Enterobacteriaceae, Vibrio cholerae and Staphylococcus aureus Bacterial Food Pathogens

Science.gov (United States)

Andersen, Jody L.; He, Gui-Xin; Kakarla, Prathusha; KC, Ranjana; Kumar, Sanath; Lakra, Wazir Singh; Mukherjee, Mun Mun; Ranaweera, Indrika; Shrestha, Ugina; Tran, Thuy; Varela, Manuel F.

2015-01-01

Foodborne illnesses caused by bacterial microorganisms are common worldwide and constitute a serious public health concern. In particular, microorganisms belonging to the Enterobacteriaceae and Vibrionaceae families of Gram-negative bacteria, and to the Staphylococcus genus of Gram-positive bacteria are important causative agents of food poisoning and infection in the gastrointestinal tract of humans. Recently, variants of these bacteria have developed resistance to medically important chemotherapeutic agents. Multidrug resistant Escherichia coli, Salmonella enterica, Vibrio cholerae, Enterobacter spp., and Staphylococcus aureus are becoming increasingly recalcitrant to clinical treatment in human patients. Of the various bacterial resistance mechanisms against antimicrobial agents, multidrug efflux pumps comprise a major cause of multiple drug resistance. These multidrug efflux pump systems reside in the biological membrane of the bacteria and actively extrude antimicrobial agents from bacterial cells. This review article summarizes the evolution of these bacterial drug efflux pump systems from a molecular biological standpoint and provides a framework for future work aimed at reducing the conditions that foster dissemination of these multidrug resistant causative agents through human populations. PMID:25635914

Protein disulfide bond generation in Escherichia coli DsbB–DsbA

International Nuclear Information System (INIS)

Inaba, Kenji

2008-01-01

The crystal structure of the DsbB–DsbA–ubiquinone ternary complex has revealed a mechanism of protein disulfide bond generation in Escherichia coli. Protein disulfide bond formation is catalyzed by a series of Dsb enzymes present in the periplasm of Escherichia coli. The crystal structure of the DsbB–DsbA–ubiquinone ternary complex provided important insights into mechanisms of the de novo disulfide bond generation cooperated by DsbB and ubiquinone and of the disulfide bond shuttle from DsbB to DsbA. The structural basis for prevention of the crosstalk between the DsbA–DsbB oxidative and the DsbC–DsbD reductive pathways has also been proposed

Antibiotic Resistance and Antibiotic Resistance Genes in Escherichia coli Isolates from Hospital Wastewater in Vietnam.

Science.gov (United States)

Lien, La Thi Quynh; Lan, Pham Thi; Chuc, Nguyen Thi Kim; Hoa, Nguyen Quynh; Nhung, Pham Hong; Thoa, Nguyen Thi Minh; Diwan, Vishal; Tamhankar, Ashok J; Stålsby Lundborg, Cecilia

2017-06-29

The environmental spread of antibiotic-resistant bacteria has been recognised as a growing public health threat for which hospitals play a significant role. The aims of this study were to investigate the prevalence of antibiotic resistance and antibiotic resistance genes (ARGs) in Escherichia coli isolates from hospital wastewater in Vietnam. Wastewater samples before and after treatment were collected using continuous sampling every month over a year. Standard disk diffusion and E-test were used for antibiotic susceptibility testing. Extended-spectrum beta-lactamase (ESBL) production was tested using combined disk diffusion. ARGs were detected by polymerase chain reactions. Resistance to at least one antibiotic was detected in 83% of isolates; multidrug resistance was found in 32%. The highest resistance prevalence was found for co-trimoxazole (70%) and the lowest for imipenem (1%). Forty-three percent of isolates were ESBL-producing, with the bla TEM gene being more common than bla CTX-M . Co-harbouring of the bla CTX-M , bla TEM and qepA genes was found in 46% of isolates resistant to ciprofloxacin. The large presence of antibiotic-resistant E. coli isolates combined with ARGs in hospital wastewater, even post-treatment, poses a threat to public health. It highlights the need to develop effective processes for hospital wastewater treatment plants to eliminate antibiotic resistant bacteria and ARGs.

Epidemiology of 3rd generation cephalosporin-resistant Escherichia coli on dairy farms

Science.gov (United States)

Dairy cattle have been identified as a reservoir for 3rd generation cephalosporin (3GC)-resistant Escherichia coli. We previously identified 3GC-resistant E. coli from manure composite samples of calves and cows in a survey of 80 farms in Pennsylvania. Resistant strains were most frequently isolated...

UV irradiation alters deoxynucleoside triphosphate pools in Escherichia coli

International Nuclear Information System (INIS)

Das, S.K.; Loeb, L.A.

1984-01-01

UV irradiation of exponentially growing Escherichia coli increased intracellular concentration of dATP and dTTP without significantly changing the concentrations of dGTP and dCTP. These selective increases in dATP and dTTP pools are seen in wild-type E. coli K12 and AB1157, as well as in recA and umuC strains, and are proportional to UV dose. The possible significance of these findings with respect to induction of the SOS response and nontargeted mutagenesis are discussed. (orig.)

Current pathogenic Escherichia coli foodborne outbreak cases and therapy development.

Science.gov (United States)

Yang, Shih-Chun; Lin, Chih-Hung; Aljuffali, Ibrahim A; Fang, Jia-You

2017-08-01

Food contamination by pathogenic microorganisms has been a serious public health problem and a cause of huge economic losses worldwide. Foodborne pathogenic Escherichia coli (E. coli) contamination, such as that with E. coli O157 and O104, is very common, even in developed countries. Bacterial contamination may occur during any of the steps in the farm-to-table continuum from environmental, animal, or human sources and cause foodborne illness. To understand the causes of the foodborne outbreaks by E. coli and food-contamination prevention measures, we collected and investigated the past 10 years' worldwide reports of foodborne E. coli contamination cases. In the first half of this review article, we introduce the infection and symptoms of five major foodborne diarrheagenic E. coli pathotypes: enteropathogenic E. coli (EPEC), Shiga toxin-producing E. coli/enterohemorrhagic E. coli (STEC/EHEC), Shigella/enteroinvasive E. coli (EIEC), enteroaggregative E. coli (EAEC), and enterotoxigenic E. coli (ETEC). In the second half of this review article, we introduce the foodborne outbreak cases caused by E. coli in natural foods and food products. Finally, we discuss current developments that can be applied to control and prevent bacterial food contamination.

Zoonotic Potential and Antibiotic Resistance of Escherichia coli in Neonatal Calves in Uruguay.

Science.gov (United States)

Umpiérrez, Ana; Bado, Inés; Oliver, Martín; Acquistapace, Sofía; Etcheverría, Analía; Padola, Nora Lía; Vignoli, Rafael; Zunino, Pablo

2017-09-27

Escherichia coli is one of the main etiological agents of neonatal calf diarrhea (NCD). The objective of this study was to assess the presence of virulence genes, genetic diversity, and antibiotic resistance mechanisms in E. coli associated with NCD in Uruguay. PCR was used to assess the presence of intimin, Shiga-like toxin, and stable and labile enterotoxin genes. Resistance to fluoroquinolones and oxyimino-cephalosporins was estimated on Müller-Hinton agar plates. Further antibiotic disc-diffusion tests were performed to assess bacterial multi-resistance. The presence of PMQR, ESBL, MCR-1, and integron genes was evaluated. Isolates were typed using ERIC-PCR, and 20 were selected for MLST, adhesion to Hep-2 cells, in vitro biofilm formation, and eukaryotic cytotoxicity. The prevalence of ETEC genes was lower than 3% in each case (estA and elt). Six isolates were EPEC (eae+) and 2 were EHEC/STEC (eae+/stx1+). The results of a diversity analysis showed high genetic heterogenicity among isolates. Additionally, different sequence types, including ST10, ST21, and ST69, were assigned to selected isolates. Thirty-six percent (96/264) of the isolates were fluoroquinolone-resistant, with 61/96 (63.5%) being multidrug-resistant. Additionally, 6 were oxyimino-cephalosporin-resistant. The qnrB, qnrS1, and bla CTX-M-14 genes were detected, whereas no isolates carried the mcr-1 gene. Isolates had the ability to adhere to Hep-2 cells and form biofilms. Only 1 isolate expressed toxins in vitro. E. coli from NCD cases in Uruguay are very diverse, potentially virulent, and may interact with eukaryotic cells. Zoonotic potential, together with resistance traits and the presence of horizontal transfer mechanisms, may play a significant role in infections caused by these microorganisms.

The Escherichia coli antiterminator protein BglG stabilizes the 5 ...

Indian Academy of Sciences (India)

Unknown

Keywords. Antitermination; mRNA stability; RNA binding protein ... factor, Rho, and the pBR322 copy number protein, Rop, have been .... Transcription analysis using the oligo- ..... Retarded RNA turnover in Escherichia coli a means of main-.

Increasing the permeability of Escherichia coli using MAC13243

DEFF Research Database (Denmark)

Muheim, Claudio; Götzke, Hansjörg; Eriksson, Anna U.

2017-01-01

molecules that make the outer membrane of Escherichia coli more permeable. We identified MAC13243, an inhibitor of the periplasmic chaperone LolA that traffics lipoproteins from the inner to the outer membrane. We observed that cells were (1) more permeable to the fluorescent probe 1-N...

Co-occurrence of colistin-resistance genes mcr-1 and mcr-3 among multidrug-resistant Escherichia coli isolated from cattle, Spain, September 2015.

Science.gov (United States)

Hernández, Marta; Iglesias, M Rocío; Rodríguez-Lázaro, David; Gallardo, Alejandro; Quijada, Narciso; Miguela-Villoldo, Pedro; Campos, Maria Jorge; Píriz, Segundo; López-Orozco, Gema; de Frutos, Cristina; Sáez, José Luis; Ugarte-Ruiz, María; Domínguez, Lucas; Quesada, Alberto

2017-08-03

Colistin resistance genes mcr-3 and mcr-1 have been detected in an Escherichia coli isolate from cattle faeces in a Spanish slaughterhouse in 2015. The sequences of both genes hybridised to same plasmid band of ca 250 kb, although colistin resistance was non-mobilisable. The isolate was producing extended-spectrum beta-lactamases and belonged to serotype O9:H10 and sequence type ST533. Here we report an mcr-3 gene detected in Europe following earlier reports from Asia and the United States. This article is copyright of The Authors, 2017.

Escherichia coli O26 IN RAW BUFFALO MILK: PRELIMINARY RESULTS

Directory of Open Access Journals (Sweden)

A. Rella

2013-02-01

Full Text Available Escherichia coli O26 is considered to be one of the most important food-borne pathogen. In this study, 120 buffalo milk samples collected in Lazio and in Apulia regions were tested for the presence of E. coli O26. One buffalo milk sample (0,8% tested positive for E. coli O26; the isolate was positive at the verocytotoxicity test and it showed resistance properties to different antimicrobial classes. These preliminary results highlight the need to monitor the foods of animal origin used for production and eaten by a wide range of persons, respect VTEC organism.

Effect of solar radiation on multidrug resistant E. coli strains and antibiotic mixture photodegradation in wastewater polluted stream.

Science.gov (United States)

Rizzo, L; Fiorentino, A; Anselmo, A

2012-06-15

The effect of solar radiation on the inactivation of multidrug resistant Escherichia coli (MDR) strains selected from an urban wastewater treatment plant (UWWTP) effluent and the change of their resistance to a mixture of three antibiotics (evaluated in terms of minimum inhibit concentration (MIC)) in wastewater polluted stream were investigated. The solar photodegradation of the mixture of the three target antibiotics (amoxicillin (AMX), ciprofloxacin (CPX), and sulfamethoxazole (SMZ)) was also evaluated. Additionally, since UWWTP effluents are possible sources of antibiotics and antibiotic resistant bacteria, the disinfection by conventional chlorination process of the UWWTP effluent inoculated with MDR strains was investigated too. Solar radiation poorly affected the inactivation of the two selected antibiotic resistant E. coli strains (40 and 60% after 180 min irradiation). Moreover, solar radiation did not affect strain resistance to AMX (MIC>256 μg/mL) and SMZ (MIC>1024 μg/mL), but affected resistance of the lower resistance strain to CPX (MIC decreased by 33% but only after 180 min of irradiation). Chlorination of wastewater sample strongly decreased the number of the two selected antibiotic resistant E. coli strains (99.667 and 99.999%), after 60 min of contact time at 2.0 mg/L initial chlorine concentration, but the resistance of survived colonies to antibiotics was unchanged. Finally, the solar photodegradation rate of the antibiotic mixture (1mg/L initial concentration respectively) resulted in the following order (half-life time): CPX (t(1/2)=24 min)risk of the development of resistance to SMZ in surface water is significantly higher compared to CPX and AMX. Copyright © 2012 Elsevier B.V. All rights reserved.

Diarrhea, Urosepsis and Hemolytic Uremic Syndrome Caused by the Same Heteropathogenic Escherichia coli Strain

NARCIS (Netherlands)

Ang, C. Wim; Bouts, Antonia H. M.; Rossen, John W. A.; van der Kuip, Martijn; van Heerde, Marc; Bökenkamp, Arend

2016-01-01

We describe an 8-month-old girl with diarrhea, urosepsis and hemolytic uremic syndrome caused by Escherichia coli. Typing of cultured E. coli strains from urine and blood revealed the presence of virulence factors from multiple pathotypes of E. coli. This case exemplifies the genome plasticity of E.

Detection of CTX-M-15 Among Uropathogenic Escherichia coli Isolated from Five Major Hospitals in Tripoli, Libya.

Science.gov (United States)

Zorgani, Abdulaziz; Almagatef, Asma; Sufya, Najib; Bashein, Abdulla; Tubbal, Abdullatif

2017-07-01

Multidrug resistance (MDR) and emergence of extended-spectrum β-lactamases (ESBLs) among uropathogenic Escherichia coli have been reported worldwide, but there was no information on the detection of bla CTX-M-15 in major teaching hospitals in Libya. The aim of the study was to investigate the occurrence of CTX-M-15 β-lactamases producers isolated from five teaching hospitals in Tripoli, Libya. A total of 346 urine samples were collected from hospitalized patients in five teaching hospitals with a diagnosis of urinary tract infection (UTI). Phenotypic confirmation of ESBLs was confirmed by E-test strip; all ESBL-producing E. coli isolates were screened for the bla CTX-M-15 gene. The distribution of ESBL-producing E. coli varied among the five hospitals. The highest proportion was identified in Tripoli Medical Centre (67.6%). There were extremely high proportions of isolates resistant to ceftriaxone, cefepime, and ceftazidime (93.0-100.0%) among ESBL producers compared to non-ESBL producers (2.2-4.7%). MDR was detected in 22.2% of isolates. The majority of isolates (85.9%) in which bla CTX-M-15 was identified were ESBL producers. There was a correlation ( p < 0.001) between expression of CTX-M-15 and resistance to ceftazidime. The isolation of MDR ESBL-producing uropathogens expressing the CTX-M-15 gene will limit the choices clinicians have to treat their patients with UTIs. Continued surveillance and implementation of efficient infection control measures are required.

Global transcriptional response of Escherichia coli MG1655 cells exposed to the oxygenated monoterpenes citral and carvacrol.

Science.gov (United States)

Chueca, Beatriz; Pérez-Sáez, Elisa; Pagán, Rafael; García-Gonzalo, Diego

2017-09-18

DNA microarrays were used to study the mechanism of bacterial inactivation by carvacrol and citral. After 10-min treatments of Escherichia coli MG1655 cells with 100 and 50ppm of carvacrol and citral, 76 and 156 genes demonstrated significant transcriptional differences (p≤0.05), respectively. Among the up-regulated genes after carvacrol treatment, we found gene coding for multidrug efflux pumps (acrA, mdtM), genes related to phage shock response (pspA, pspB, pspC, pspD, pspF and pspG), biosynthesis of arginine (argC, argG, artJ), and purine nucleotides (purC, purM). In citral-treated cells, transcription of purH and pyrB and pyrI was 2 times higher. Deletion of several differentially expressed genes confirmed the role of ygaV, yjbO, pspC, sdhA, yejG and ygaV in the mechanisms of E. coli inactivation by carvacrol and citral. These results would indicate that citral and carvacrol treatments cause membrane damage and activate metabolism through the production of nucleotides required for DNA and RNA synthesis and metabolic processes. Comparative transcriptomics of the response of E. coli to a heat treatment, which caused a significant change of the transcription of 1422 genes, revealed a much weaker response to both individual constituents of essential oils (ICs).·Thus, inactivation by citral or carvacrol was not multitarget in nature. Copyright © 2017 Elsevier B.V. All rights reserved.

Bactericidal effect of bovine lactoferrin, LFcin, LFampin and LFchimera on antibiotic-resistant Staphylococcus aureus and Escherichia coli.

Science.gov (United States)

Flores-Villaseñor, Héctor; Canizalez-Román, Adrian; Reyes-Lopez, Magda; Nazmi, Kamram; de la Garza, Mireya; Zazueta-Beltrán, Jorge; León-Sicairos, Nidia; Bolscher, Jan G M

2010-06-01

Increased prevalence of antibiotic-resistant bacteria has become a major threat to the health sector worldwide due to their virulence, limited therapeutic options and distribution in both hospital and community settings. Discovery and development of new agents to combat antibiotic-resistant bacteria is thus needed. This study therefore aimed to evaluate the ability of bovine lactoferrin (LF), peptides from two antimicrobial domains lactoferricin B (LFcin17-30) and lactoferrampin (LFampin265-284) and a chimeric construct (LFchimera) containing both peptides, as potential bactericidal agents against clinical isolates of antibiotic-resistant Staphylococcus aureus and Escherichia coli. Results in kinetics of growth show that LF chimera and peptides inhibited the growth of both bacterial species. By confocal microscopy and flow cytometry it was observed that LF and FITC-labeled peptides are able to interact with these bacteria and cause membrane permeabilization, as monitored by propidium iodide staining, these effects were decreased by preincubation with lipopolysaccharide in E. coli. By electron microscopy, a clear cellular damage was observed in bacteria after treatments with LFchimera and peptides, suggesting that interaction and membrane disruption are probably involved as a mechanism of action. In conclusion, results show that LFchimera, LF and peptides have potential as bactericidal agents in the antibiotic-resistant strains of S. aureus and E. coli and also the work strongly suggest that LFcin17-30 and LFampin265-284 acts synergistically with antibiotics against multidrug resistant EPEC and MRSA in vitro.

Temporal stability of Escherichia coli concentration patterns in two irrigation ponds in Maryland

Science.gov (United States)

Fecal contamination of water sources is an important water quality issue for agricultural irrigation ponds. Escherichia coli is a common microbial indicator used to evaluate recreational and irrigation water quality. We hypothesized that there is a temporally stable pattern of E.coli concentrations ...

Influence of bromouracil density labelling on viability of UV irradiated Escherichia coli cells

Energy Technology Data Exchange (ETDEWEB)

Brozmanova, J [Slovenska Akademia Vied, Bratislava (Czechoslovakia). Vyskumny Ustav Onkologicky

1976-01-01

Influence of 5-bromouracil cultivation on cell viability and DNA synthesis in the Escherichia coli B/r thy/sup -/ trp/sup -/ Hcr/sup +/ and Escherichia coli C thy-321 strains was followed. It was found that a 120 min cultivation in the bromouracil medium (unirradiated cells) does not essentially influence the viability of the two investigated strains but has an inhibitory effect on DNA synthesis in cells of the E. coli B/r Hcr/sup +/ strain. However, cultivation with bromouracil after ultraviolet irradiation leads to a decreased surviving ability of the irradiated cells of both investigated strains. Repair of damage induced by ultraviolet radiation probably exhausts a considerable proportion of repair activity, so that additional injury produced by bromouracil cultivation cannot be liquidated immediately.

Phylogenetic analysis of Escherichia coli isolates from healthy and diarrhoeic calves in Mashhad, Iran

Directory of Open Access Journals (Sweden)

M. Barzan

2017-03-01

Full Text Available Escherichia coli is a normal inhabitant of the gastrointestinal tract of vertebrates. Certain Escherichia coli strains have been associated with neonatal diarrhoea in ruminants. These strains can be assigned to one of the four main phylogenetic groups, A, B1, B2 and D. Several studies have shown the rela-tionship between phylogeny and pathogenicity of E. coli, a great deal can be obtained by determining the phylogroup of unknown E. coli strains. In this study, we aimed to evaluate the influence of diar-rhoea on the genetic composition of E. coli populations isolated from calves. A total of 80 Es-cherichia coli isolates were obtained from healthy and diarrhoeic calves. Phylogenetic grouping was done based on the Clermont triplex PCR method using primers targeted at three genetic markers, chuA, yjaA and TspE4.C2. According to our results, phylogenetic group A strains was the most prevalent in both healthy (37.5% and diarrhoeic calves (55%. Group B1 contained 27.5% of isolates in healthy calves, followed by group B2 (17.5%, and group D (7.5%. Also, four isolates from healthy calves were not included in the major phylogenetic groups or subgroups. A total of 14% and 4% of isolates from diarrhoeic calves beloned to phylogroups B2 and D respectively. Although no isolate from diarrhoeic calves was found to belong to group B1, there was no significant difference between healthy and diarrhoeic calves for other phylogroups. There was not a dramatic shift in E. coli phylogroup/subgroup due to occurrence of diarrhoea in calves, except for phylogroup B1 which was higher in healthy calves. This can be due to the difference in secretions of digestive system in diarrhoeic calves which can prevent the conditions for instability of Escherichia coli isolates of phy-logroup B1. The majority of isolates from both healthy and diarrhoeic calves belonged to non-pathogenic phylogentic group A and B1.

DNA microarray analysis of fim mutations in Escherichia coli

DEFF Research Database (Denmark)

Schembri, Mark; Ussery, David; Workman, Christopher

2002-01-01

Bacterial adhesion is often mediated by complex polymeric surface structures referred to as fimbriae. Type I fimbriae of Escherichia coli represent the archetypical and best characterised fimbrial system. These adhesive organelles mediate binding to D-mannose and are directly associated...... we have used DNA microarray analysis to examine the molecular events involved in response to fimbrial gene expression in E. coli K-12. Observed differential expression levels of the fim genes were in good agreement with our current knowledge of the stoichiometry of type I fimbriae. Changes in fim...

Alterations induced in Escherichia Coli cells by gamma radiation

International Nuclear Information System (INIS)

Kappke, J.; Schelin, H.R.; Paschuk, S.A.; Denyak, V.; Silva, E.R. da; Jesus, E.F.O. de; Lopes, R.T.; Carlin, N.; Toledo, E.S.

2007-01-01

Modifications occurred in Escherichia coli cells exposed to gamma radiation ( 60 Co source) were investigated. The irradiations were done at the LIN-COPPE laboratory of the UFRJ and the analysis at the Biology Department of the UTFPR. The E. coli cells were irradiated with 30, 60, 90, 120, 150, 180, 210, 240, 300, 480, 600 e 750 Gy doses. The samples were analyzed with Gram-stain, biochemical tests in EPM, MIO and Lysine Broth, Simmons Cytrate Medium and Rhamnose Broth, antibiogram and isolation of auxotrophic mutants. It was observed that for the received doses the E. coli did not show morphological alterations in the tests. Some E. Coli cells showed to be able to deaminade the L-tryptophan or they changed their sensibility for amoxillin and cephaloonine after the irradiation. The existence of aauxotrophic mutants after irradiation was also verified. (author)

Lon gene and photoprotection in Escherichia coli K-12

Energy Technology Data Exchange (ETDEWEB)

Waksman, G.; Thomas, G.; Favre, A. (Institut de Recherche en Biologie Moleculaire, Group de Photobiologie Moleculaire, Paris (France))

1984-03-01

Photoprotection, i.e. the increased resistance of the cells preilluminated with near ultraviolet light (300-380 nm) to the lethal action of 254nm radiations requires either an integrated prophage or a recA mutation in Escherichia coli K12 strains. Significant photoprotection occurs in an Escherichia coli K12 recA/sup +/ cell containing the lon allele responsible for filamentous growth after 254nm irradiation. The Fil phenotype can be suppressed by the sfiA or sfiB suppressor genes. Since the E. coli K12 recA/sup +/ lon sfiB strain exhibits no more photoprotection, it is concluded that in lon strains photoprotection is due to the abolition of the 254nm induced filamentation by the near ultraviolet treatment. In addition, near ultraviolet illumination of the cells leads to a severe restriction of the bulk protein synthesis. This effect is observed only in nuv/sup +/ cells that contain 4-thiouridine the chromophore responsible for photoprotection. It is proposed that in lon (lysogenic strains) photoprotection is due to prevention of the SOS response. During the growth lag, the low residual level of protein synthesis does not allow the induction of the SOS response and accordingly prevents filamentation (the lytic cycle).

Multiple Antimicrobial Resistance of Escherichia coli Isolated from Chickens in Iran.

Science.gov (United States)

Talebiyan, Reza; Kheradmand, Mehdi; Khamesipour, Faham; Rabiee-Faradonbeh, Mohammad

2014-01-01

Antimicrobial agents are used extremely in order to reduce the great losses caused by Escherichia coli infections in poultry industry. In this study, 318 pathogenic Escherichia coli (APEC) strains isolated from commercial broiler flocks with coli-septicemia were examined for antimicrobials of both veterinary and human significance by disc diffusion method. Multiple resistances to antimicrobial agents were observed in all the isolates. Resistance to the antibiotics was as follows: Tylosin (88.68%), Erythromycin (71.70%), Oxytetracycline (43.40%), Sulfadimethoxine-Trimethoprim (39.62%), Enrofloxacin (37.74%), Florfenicol (35.85%), Chlortetracycline (33.96%), Doxycycline (16.98%), Difloxacin (32.08%), Danofloxacin (28.30%), Chloramphenicol (20.75%), Ciprofloxacin (7.55%), and Gentamicin (5.66%). This study showed resistance against the antimicrobial agents that are commonly applied in poultry, although resistance against the antibiotics that are only applied in humans or less frequently used in poultry was significantly low. This study emphasizes on the occurrence of multiple drug resistant E. coli among diseased broiler chickens in Iran. The data revealed the relative risks of using antimicrobials in poultry industry. It also concluded that use of antibiotics must be limited in poultry farms in order to reduce the antibiotic resistances.

Multiple Antimicrobial Resistance of Escherichia coli Isolated from Chickens in Iran

Directory of Open Access Journals (Sweden)

Reza Talebiyan

2014-01-01

Full Text Available Antimicrobial agents are used extremely in order to reduce the great losses caused by Escherichia coli infections in poultry industry. In this study, 318 pathogenic Escherichia coli (APEC strains isolated from commercial broiler flocks with coli-septicemia were examined for antimicrobials of both veterinary and human significance by disc diffusion method. Multiple resistances to antimicrobial agents were observed in all the isolates. Resistance to the antibiotics was as follows: Tylosin (88.68%, Erythromycin (71.70%, Oxytetracycline (43.40%, Sulfadimethoxine-Trimethoprim (39.62%, Enrofloxacin (37.74%, Florfenicol (35.85%, Chlortetracycline (33.96%, Doxycycline (16.98%, Difloxacin (32.08%, Danofloxacin (28.30%, Chloramphenicol (20.75%, Ciprofloxacin (7.55%, and Gentamicin (5.66%. This study showed resistance against the antimicrobial agents that are commonly applied in poultry, although resistance against the antibiotics that are only applied in humans or less frequently used in poultry was significantly low. This study emphasizes on the occurrence of multiple drug resistant E. coli among diseased broiler chickens in Iran. The data revealed the relative risks of using antimicrobials in poultry industry. It also concluded that use of antibiotics must be limited in poultry farms in order to reduce the antibiotic resistances.

Energetics of sodium efflux from Escherichia coli

International Nuclear Information System (INIS)

Borbolla, M.G.; Rosen, B.P.

1984-01-01

When energy-starved cells of Escherichia coli were passively loaded with 22 Na+, efflux of sodium could be initiated by addition of a source of metabolic energy. Conditions were established where the source of energy was phosphate bond energy, an electrochemical proton gradient, or both. Only an electrochemical proton gradient was required for efflux from intact cells. These results are consistent with secondary exchange of Na+ for H+ catalyzed by a sodium/proton antiporter

Antibiotic resistance profile of Escherichia coli isolated from five ...

African Journals Online (AJOL)

Information on the resistance profiles of clinical and non clinical human bacteria isolates in the developing countries can serve as important means of understanding the human pathogens drug resistance interactions in the zone. Escherichia coli isolated from five geopolitical zones of Nigeria were screened for anti-microbial ...

Occurrence of Escherichia coli in Brassica rapa L. chinensis ...

African Journals Online (AJOL)

Low quality water has become valuable resource with restricted or unrestricted use in food production depending on its quality. This study has quantified the occurrence of Escherichia coli in Brassica rapa L. chinensis (Chinese cabbage) vegetables and low quality irrigation water. A total of 106 samples including Chinese ...

Prevalence of Escherichia coli virulence genes in patients with ...

African Journals Online (AJOL)

In this study, we investigated the prevalence of the virulence genes specific for five major pathogroups of diarrheagenic Escherichia coli (DEC) in primary cultures from diarrhoeagenic patients in Burkina Faso. Methodology: From September 2016 to Mars 2017, a total of 211 faecal samples from diarrhoeagenic patients from ...

THE WIDESPREAD OCCURRENCE OF THE ENTEROHEMOLYSIN GENE EHLYA AMONG ENVIRONMENTAL STRAINS OF ESCHERICHIA COLI

Science.gov (United States)

The putative virulence factor enterohemolysin, encoded for by the ehlyA gene, has been closely associated with the pathogenic enterohemorrhagic Escherichia coli (EHEC) group. E. coli isolates from effluents from seven geographically dispersed municipal ...

Screening for virulence genes in Escherichia coli O157:H7 obtained ...

African Journals Online (AJOL)

Eighty (80) sources of drinking water comprising boreholes (24), streams (3), wells (29), pipe-borne (5) and 19 sachet water samples were collected between March 2014 and February 2015. Escherichia coli (E.coli) O157:H7 was isolated by enrichment in Tryptone soy broth at elevated temperature and streaking on Eosin ...

beta-Chloro-L-alanine inhibition of the Escherichia coli alanine-valine transaminase.

OpenAIRE

Whalen, W A; Wang, M D; Berg, C M

1985-01-01

beta-Chloro-L-alanine, an amino acid analog which inhibits a number of enzymes, reversibly inhibited the Escherichia coli K-12 alanine-valine transaminase, transaminase C. This inhibition, along with the inhibition of transaminase B, accounted for the isoleucine-plus-valine requirement of E. coli in the presence of beta-chloro-L-alanine.

Formate detection by potassium permanganate for enhanced hydrogen production in Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Maeda, Toshinari [Artie McFerrin Department of Chemical Engineering, 220 Jack E. Brown Building, Texas A and M University, College Station, TX 77843-3122 (United States); Wood, Thomas K. [Artie McFerrin Department of Chemical Engineering, 220 Jack E. Brown Building, Texas A and M University, College Station, TX 77843-3122 (United States); Department of Biology, Texas A and M University, College Station, TX 77843-3258 (United States); Zachry Department of Civil and Environmental Engineering, Texas A and M University, College Station, TX 77843-3136 (United States)

2008-05-15

Mutagenesis of Escherichia coli for hydrogen production is difficult since there is no high-throughput screen. Here we describe a method for rapid detection of enhanced hydrogen production by engineered strains by detecting formate via potassium permanganate; in E. coli, hydrogen is synthesized from formate using the formate hydrogen lyase system. (author)

Fluoroquinolone-resistant Escherichia coli carriage in long-term care facility.

Science.gov (United States)

Maslow, Joel N; Lee, Betsy; Lautenbach, Ebbing

2005-06-01

We conducted a cross-sectional study to determine the prevalence of, and risk factors for, colonization with fluoroquinolone (FQ)-resistant Escherichia coli in residents in a long-term care facility. FQ-resistant E. coli were identified from rectal swabs for 25 (51%) of 49 participants at study entry. On multivariable analyses, prior FQ use was the only independent risk factor for FQ-resistant E. coli carriage and was consistent for FQ exposures in the previous 3, 6, 9, or 12 months. Pulsed-field gel electrophoresis of FQ-resistant E. coli identified clonal spread of 1 strain among 16 residents. Loss (6 residents) or acquisition (7 residents) of FQ-resistant E. coli was documented and was associated with de novo colonization with genetically distinct strains. Unlike the case in the hospital setting, FQ-resistant E. coli carriage in long-term care facilities is associated with clonal spread.

Is Escherichia coli urinary tract infection a zoonosis?

DEFF Research Database (Denmark)

Jacobsen, L.; Garneau, P.; Bruant, G.

2012-01-01

Recently, it has been suggested that the Escherichia coli causing urinary tract infection (UTI) may come from meat and animals. The purpose was to investigate if a clonal link existed between E. coli from animals, meat and UTI patients. Twenty-two geographically and temporally matched B2 E. coli...... from UTI patients, community-dwelling humans, broiler chicken meat, pork, and broiler chicken, previously identified to exhibit eight virulence genotypes by microarraydetection of approximately 300 genes, were investigated for clonal relatedness by PFGE. Nine isolates were selected and tested...... for in vivo virulence in the mouse model of ascending UTI. UTI and community-dwelling human strains were closely clonally related to meat strains. Several human derived strains were also clonally interrelated. All nine isolates regardless of origin were virulent in the UTI model with positive urine, bladder...

Multiplex Genome Editing in Escherichia coli

DEFF Research Database (Denmark)

Ingemann Jensen, Sheila; Nielsen, Alex Toftgaard

2018-01-01

Lambda Red recombineering is an easy and efficient method for generating genetic modifications in Escherichia coli. For gene deletions, lambda Red recombineering is combined with the use of selectable markers, which are removed through the action of, e.g., flippase (Flp) recombinase. This PCR......-based engineering method has also been applied to a number of other bacteria. In this chapter, we describe a recently developed one plasmid-based method as well as the use of a strain with genomically integrated recombineering genes, which significantly speeds up the engineering of strains with multiple genomic...

Recombinant protein production data after expression in the bacterium Escherichia coli

Directory of Open Access Journals (Sweden)

J. Enrique Cantu-Bustos

2016-06-01

Full Text Available Fusion proteins have become essential for the expression and purification of recombinant proteins in Escherichia coli. The metal-binding protein CusF has shown several features that make it an attractive fusion protein and affinity tag: "Expression and purification of recombinant proteins in Escherichia coli tagged with the metal-binding protein CusF" (Cantu-Bustos et al., 2016 [1]. Here we present accompanying data from protein expression experiments; we tested different protein tags, temperatures, expression times, cellular compartments, and concentrations of inducer in order to obtain soluble protein and low formation of inclusion bodies. Additionally, we present data from the purification of the green fluorescent protein (GFP tagged with CusF, using Ag(I metal affinity chromatography.

Optimizing the feeding operation of recombinant Escherichia coli ...

African Journals Online (AJOL)

Recombinant Escherichia coli BL21 was used to produce human-like collagen in fed-batch culture. After building and analyzing the kinetic models of fed-batch cultures, the maximum specific growth rate, Yx/s and Yp/s were 0.411 h-1 , 0.428 g·g-1 and 0.0716 g/g, respectively. The square error of cell growth models, glucose ...

ANALISIS CEMARAN BAKTERI Escherichia coli ANALISIS CEMARAN BAKTERI Escherichia coli ANALISIS CEMARAN BAKTERI Escherichia coli

OpenAIRE

ANGGREINI, RAHAYU

2015-01-01

2015 RAHAYU ANGGREINI coli Penelitian ini bertujuan untuk melakukan identifikasi cemaran bakteri E. coli O157:H7 pada daging sapi di kota Makassar. Sampel pada penelitian ini sebanyak 72 sampel Kata Kunci : Daging sapi, pasar tradisional, E. coli, E. coli O157:H7, kontaminasi bakteri, identifikasi E. coli O157:H7.

Sequencing of Escherichia coli that cause persistent and transient Mastitis

Science.gov (United States)

The genomes of two strains of Escherichia coli that cause bovine mastitis were sequenced. These strains are known to be associated with persistent and transient mastitis: strain ECA-B causes a transient infection, and ECC-M leads to a persistent infection....

Escherichia coli and other Enterobacteriaceae: Food poisoning and health effects

Science.gov (United States)

The family Enterobactericeae consists of rod-shaped, Gram-negative, facultatively anaerobic, non-spore forming bacteria and also includes the food-borne pathogens, Cronobacter spp., Escherichia coli, Salmonella enterica, Shigella spp., and Yersinia spp. Illness caused by these pathogens is acquired...

Presence of Type I-F CRISPR/Cas systems is associated with antimicrobial susceptibility in Escherichia coli.

Science.gov (United States)

Aydin, Seyid; Personne, Yoann; Newire, Enas; Laverick, Rebecca; Russell, Oliver; Roberts, Adam P; Enne, Virve I

2017-08-01

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and their associated cas genes are sequence-specific DNA nuclease systems found in bacteria and archaea. CRISPR/Cas systems use RNA transcripts of previously acquired DNA (spacers) to target invading genetic elements with the same sequence, including plasmids. In this research we studied the relationship between CRISPR/Cas systems and multidrug resistance in Escherichia coli . The presence of Type I-E and Type I-F CRISPR systems was investigated among 82 antimicrobial-susceptible and 96 MDR clinical E. coli isolates by PCR and DNA sequencing. Phylogrouping and MLST were performed to determine relatedness of isolates. RT-PCR was performed to ascertain the expression of associated cas genes. Type I-F CRISPR was associated with the B2 phylogroup and was significantly overrepresented in the susceptible group (22.0%) compared with the MDR group (2.1%). The majority of CRISPR I-F-containing isolates had spacer sequences that matched IncF and IncI plasmids. RT-PCR demonstrated that Type I-F cas genes were expressed and therefore potentially functional. The CRISPR I-F system is more likely to be found in antimicrobial-susceptible E. coli . Given that the Type I-F system is expressed in WT isolates, we suggest that this difference could be due to the CRISPR system potentially interfering with the acquisition of antimicrobial resistance plasmids, maintaining susceptibility in these isolates. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of chlortetracycline and copper supplementation on antimicrobial resistance of fecal Escherichia coli from weaned pigs.

Science.gov (United States)

Agga, G E; Scott, H M; Amachawadi, R G; Nagaraja, T G; Vinasco, J; Bai, J; Norby, B; Renter, D G; Dritz, S S; Nelssen, J L; Tokach, M D

2014-06-01

Feed-grade chlortetracycline (CTC) and copper are both widely utilized in U.S. pig production. Cluster randomized experiment was conducted to evaluate the effects of CTC and copper supplementation in weaned pigs on antimicrobial resistance (AMR) among fecal Escherichia coli. Four treatment groups: control, copper, CTC, or copper plus CTC were randomly allocated to 32 pens with five pigs per pen. Fecal samples were collected weekly from three pigs per pen for six weeks. Two E. coli isolates per fecal sample were tested for phenotypic and genotypic resistance against antibiotics and copper. Data were analyzed with multilevel mixed effects logistic regression, multivariate probit analysis and discrete time survival analysis. CTC-supplementation was significantly (99% [95% CI=98-100%]) associated with increased tetracycline resistance compared to the control group (95% [95% CI=94-97%]). Copper supplementation was associated with decreased resistance to most of the antibiotics tested, including cephalosporins, over the treatment period. Overall, 91% of the E. coli isolates were multidrug resistant (MDR) (resistant to ≥3 antimicrobial classes). tetA and blaCMY-2 genes were positively associated (PpcoD were negatively associated with MDR. tetA and blaCMY-2 were positively associated with each other and in turn, these were negatively associated with both tetB and pcoD genes; which were also positively associated with one another. Copper minimum inhibitory concentration was not affected by copper supplementation or by pcoD gene carriage. CTC supplementation was significantly associated with increased susceptibilities of E. coli to copper (HR=7 [95% CI=2.5-19.5]) during treatment period. In conclusion, E. coli isolates from the nursery pigs exhibited high levels of antibiotic resistance, with diverse multi-resistant phenotypic profiles. The roles of copper supplementation in pig production, and pco-mediated copper resistance among E. coli in particular, need to be further

Analysis of early-onset bloodstream infection due to Escherichia coli infection in premature babies

OpenAIRE

Chen, I-Lun; Huang, Hsin-Chun; Wu, Chih-Te; Ou-Yang, Mei-Chen; Chung, Mei-Yung; Chen, Chih-Cheng; Suen, Jau-Ling; Hung, Chih-Hsing

2017-01-01

Abstract In early-onset bacteremia among preterm neonates, Escherichia coli (E. coli) is the main pathogen and can cause a high mortality rate. Thus, the predictive factors of mortality and extended-spectrum ?-lactamase (ESBL)-producing E. coli in preterm babies with E. coli early-onset bacteremia were reported. We retrospectively reviewed preterm neonates who had E. coli bacteremia occurring within 3 days after birth between 2004 and 2015. Maternal and perinatal information were collected fr...

Recent Advances in Understanding Enteric Pathogenic Escherichia coli

Science.gov (United States)

Croxen, Matthew A.; Law, Robyn J.; Scholz, Roland; Keeney, Kristie M.; Wlodarska, Marta

2013-01-01

SUMMARY Although Escherichia coli can be an innocuous resident of the gastrointestinal tract, it also has the pathogenic capacity to cause significant diarrheal and extraintestinal diseases. Pathogenic variants of E. coli (pathovars or pathotypes) cause much morbidity and mortality worldwide. Consequently, pathogenic E. coli is widely studied in humans, animals, food, and the environment. While there are many common features that these pathotypes employ to colonize the intestinal mucosa and cause disease, the course, onset, and complications vary significantly. Outbreaks are common in developed and developing countries, and they sometimes have fatal consequences. Many of these pathotypes are a major public health concern as they have low infectious doses and are transmitted through ubiquitous mediums, including food and water. The seriousness of pathogenic E. coli is exemplified by dedicated national and international surveillance programs that monitor and track outbreaks; unfortunately, this surveillance is often lacking in developing countries. While not all pathotypes carry the same public health profile, they all carry an enormous potential to cause disease and continue to present challenges to human health. This comprehensive review highlights recent advances in our understanding of the intestinal pathotypes of E. coli. PMID:24092857

Transcriptome Changes of Escherichia coli, Enterococcus faecalis, and Escherichia coli O157:H7 Laboratory Strains in Response to Photo-Degraded DOM

Directory of Open Access Journals (Sweden)

Adelumola Oladeinde

2018-05-01

Full Text Available In this study, we investigated gene expression changes in three bacterial strains (Escherichia coli C3000, Escherichia coli O157:H7 B6914, and Enterococcus faecalis ATCC 29212, commonly used as indicators of water quality and as control strains in clinical, food, and water microbiology laboratories. Bacterial transcriptome responses from pure cultures were monitored in microcosms containing water amended with manure-derived dissolved organic matter (DOM, previously exposed to simulated sunlight for 12 h. We used RNA sequencing (RNA-seq and quantitative real-time reverse transcriptase (qRT-PCR to compare differentially expressed temporal transcripts between bacteria incubated in microcosms containing sunlight irradiated and non-irradiated DOM, for up to 24 h. In addition, we used whole genome sequencing simultaneously with RNA-seq to identify single nucleotide variants (SNV acquired in bacterial populations during incubation. These results indicate that E. coli and E. faecalis have different mechanisms for removal of reactive oxygen species (ROS produced from irradiated DOM. They are also able to produce micromolar concentrations of H2O2 from non-irradiated DOM, that should be detrimental to other bacteria present in the environment. Notably, this study provides an assessment of the role of two conjugative plasmids carried by the E. faecalis and highlights the differences in the overall survival dynamics of environmentally-relevant bacteria in the presence of naturally-produced ROS.

D10 value determination for Escherichia coli O157:H7 in different cultivations

International Nuclear Information System (INIS)

Oliveira, Sergio Eduardo M. de; Pires, Luis Fernando G.; Vital, Helio de C.

2002-01-01

Escherichia coli serum type O157:H7 is a highly pathogenic bacterium. Inside the human body, that microorganism causes a disease that leads to bloody diarrhea, stoppage of kidney functions and clots in the brain. That type of infection has been related to the consumption of different varieties of foods, mainly meat and other products of animal origin. Irradiation is an efficient method for elimination of pathogenic and spoiling microorganisms in foods. Thus, this work investigates the use of gamma irradiation for elimination of Escherichia coli O157:H7. For that purpose, inoculated samples in trypticase soy broth and saline solution 0,85% media were exposed to several gamma radiation doses. Counting the number of surviving bacteria yielded the following D 10 values for Escherichia coli O157:H7: 98±7 Gy, in trypticase soy broth and 49±4 Gy in saline solution 0,85% medium. (author)

Genomic Comparative Study of Bovine Mastitis Escherichia coli.

Science.gov (United States)

Kempf, Florent; Slugocki, Cindy; Blum, Shlomo E; Leitner, Gabriel; Germon, Pierre

2016-01-01

Escherichia coli, one of the main causative agents of bovine mastitis, is responsible for significant losses on dairy farms. In order to better understand the pathogenicity of E. coli mastitis, an accurate characterization of E. coli strains isolated from mastitis cases is required. By using phylogenetic analyses and whole genome comparison of 5 currently available mastitis E. coli genome sequences, we searched for genotypic traits specific for mastitis isolates. Our data confirm that there is a bias in the distribution of mastitis isolates in the different phylogenetic groups of the E. coli species, with the majority of strains belonging to phylogenetic groups A and B1. An interesting feature is that clustering of strains based on their accessory genome is very similar to that obtained using the core genome. This finding illustrates the fact that phenotypic properties of strains from different phylogroups are likely to be different. As a consequence, it is possible that different strategies could be used by mastitis isolates of different phylogroups to trigger mastitis. Our results indicate that mastitis E. coli isolates analyzed in this study carry very few of the virulence genes described in other pathogenic E. coli strains. A more detailed analysis of the presence/absence of genes involved in LPS synthesis, iron acquisition and type 6 secretion systems did not uncover specific properties of mastitis isolates. Altogether, these results indicate that mastitis E. coli isolates are rather characterized by a lack of bona fide currently described virulence genes.

Effect of solar radiation on multidrug resistant E. coli strains and antibiotic mixture photodegradation in wastewater polluted stream

International Nuclear Information System (INIS)

Rizzo, L.; Fiorentino, A.; Anselmo, A.

2012-01-01

The effect of solar radiation on the inactivation of multidrug resistant Escherichia coli (MDR) strains selected from an urban wastewater treatment plant (UWWTP) effluent and the change of their resistance to a mixture of three antibiotics (evaluated in terms of minimum inhibit concentration (MIC)) in wastewater polluted stream were investigated. The solar photodegradation of the mixture of the three target antibiotics (amoxicillin (AMX), ciprofloxacin (CPX), and sulfamethoxazole (SMZ)) was also evaluated. Additionally, since UWWTP effluents are possible sources of antibiotics and antibiotic resistant bacteria, the disinfection by conventional chlorination process of the UWWTP effluent inoculated with MDR strains was investigated too. Solar radiation poorly affected the inactivation of the two selected antibiotic resistant E. coli strains (40 and 60% after 180 min irradiation). Moreover, solar radiation did not affect strain resistance to AMX (MIC > 256 μg/mL) and SMZ (MIC > 1024 μg/mL), but affected resistance of the lower resistance strain to CPX (MIC decreased by 33% but only after 180 min of irradiation). Chlorination of wastewater sample strongly decreased the number of the two selected antibiotic resistant E. coli strains (99.667 and 99.999%), after 60 min of contact time at 2.0 mg/L initial chlorine concentration, but the resistance of survived colonies to antibiotics was unchanged. Finally, the solar photodegradation rate of the antibiotic mixture (1 mg/L initial concentration respectively) resulted in the following order (half-life time): CPX (t 1/2 = 24 min) 1/2 = 99 min) 1/2 = 577 min). Accordingly, the risk of the development of resistance to SMZ in surface water is significantly higher compared to CPX and AMX. - Highlights: ► Solar radiation did not affect E. coli strain resistance to AMX and SMZ. ► Solar radiation affected the resistance of one E. coli strain to CPX. ► MIC for CPX decreased by 33% after 180 min of solar irradiation. �

Effect of solar radiation on multidrug resistant E. coli strains and antibiotic mixture photodegradation in wastewater polluted stream

Energy Technology Data Exchange (ETDEWEB)

Rizzo, L., E-mail: l.rizzo@unisa.it [Department of Civil Engineering, University of Salerno, via Ponte don Melillo, 1-84084 Fisciano (Italy); Fiorentino, A. [Department of Civil Engineering, University of Salerno, via Ponte don Melillo, 1-84084 Fisciano (Italy); Anselmo, A. [Pluriacque, via Alento, 84060 Prignano Cilento (Italy)

2012-06-15

The effect of solar radiation on the inactivation of multidrug resistant Escherichia coli (MDR) strains selected from an urban wastewater treatment plant (UWWTP) effluent and the change of their resistance to a mixture of three antibiotics (evaluated in terms of minimum inhibit concentration (MIC)) in wastewater polluted stream were investigated. The solar photodegradation of the mixture of the three target antibiotics (amoxicillin (AMX), ciprofloxacin (CPX), and sulfamethoxazole (SMZ)) was also evaluated. Additionally, since UWWTP effluents are possible sources of antibiotics and antibiotic resistant bacteria, the disinfection by conventional chlorination process of the UWWTP effluent inoculated with MDR strains was investigated too. Solar radiation poorly affected the inactivation of the two selected antibiotic resistant E. coli strains (40 and 60% after 180 min irradiation). Moreover, solar radiation did not affect strain resistance to AMX (MIC > 256 {mu}g/mL) and SMZ (MIC > 1024 {mu}g/mL), but affected resistance of the lower resistance strain to CPX (MIC decreased by 33% but only after 180 min of irradiation). Chlorination of wastewater sample strongly decreased the number of the two selected antibiotic resistant E. coli strains (99.667 and 99.999%), after 60 min of contact time at 2.0 mg/L initial chlorine concentration, but the resistance of survived colonies to antibiotics was unchanged. Finally, the solar photodegradation rate of the antibiotic mixture (1 mg/L initial concentration respectively) resulted in the following order (half-life time): CPX (t{sub 1/2} = 24 min) < AMX (t{sub 1/2} = 99 min) < SMZ (t{sub 1/2} = 577 min). Accordingly, the risk of the development of resistance to SMZ in surface water is significantly higher compared to CPX and AMX. - Highlights: Black-Right-Pointing-Pointer Solar radiation did not affect E. coli strain resistance to AMX and SMZ. Black-Right-Pointing-Pointer Solar radiation affected the resistance of one E. coli strain

Modeling the inactivation of Escherichia coli 0157:H7 and uropathogenic E.coli in ground chicken by high pressure processing and thymol

Science.gov (United States)

Disease causing Escherichia coli commonly found in meat and poultry include intestinal pathogenic E. coli (iPEC) as well as extraintestinal types such as the Uropathogenic E. coli (UPEC). In this study we compare the resistance of iPEC (O157:H7) to UPEC in chicken meat using High Pressure Processing...

Modeling the inactivatin of Escherichia coli 0157:H7 and uropathogenic E. coli in ground beef by high pressure processing and citral

Science.gov (United States)

Disease causing Escherichia coli commonly found in meat and poultry include intestinal pathogenic E. coli (iPEC) as well as extraintestinal types such as the Uropathogenic E. coli (UPEC). In this study we compared the resistance of iPEC (O157:H7) to UPEC in ground beef using High Pressure Processing...

Genetic analysis of an Escherichia coli urease locus: evidence of DNA rearrangement.

OpenAIRE

Collins, C M; Falkow, S

1988-01-01

Ureolytic Escherichia coli strains are uncommon clinical isolates. The urease phenotype in a large percentage of these isolates is unstable and lost upon storage. We examined two urease-positive uropathogenic E. coli isolates that give off urease-negative segregants and determined that the urease phenotype was chromosomally encoded. The urease phenotype was cloned from E. coli 1021 and found to be encoded on a 9.4-kilobase HindIII restriction fragment. Transposon mutagenesis indicated that at...

Peptide nucleic acid (PNA) antisense effects in Escherichia coli

DEFF Research Database (Denmark)

Good, L; Nielsen, P E

1999-01-01

Antisense peptide nucleic acid (PNA) can be used to control cell growth, gene expression and growth phenotypes in the bacteria Escherichia coli. PNAs targeted to the RNA components of the ribosome can inhibit translation and cell growth, and PNAs targeted to mRNA can limit gene expression with gene...... and sequence specificity. In an E. coli cell extract, efficient inhibition is observed when using PNA concentrations in the nanomolar range, whereas micromolar concentrations are required for inhibition in growing cells. A mutant strain of E. coli that is more permeable to antibiotics also is more susceptible...... to antisense PNAs than the wild type. This chapter details methods for testing the antisense activities of PNA in E. coli. As an example of the specific antisense inhibition possible, we show the effects of an anti-beta-galactosidase PNA in comparison to control PNAs. With improvements in cell uptake...

Escherichia coli bacteraemia in patients with and without haematological malignancies

DEFF Research Database (Denmark)

Olesen, B; Kolmos, H J; Orskov, F

1998-01-01

We compared serotypes, virulence factors and susceptibility to antibiotics of Escherichia coli strains isolated from 282 patients with bacteraemia. Thirty-five of these were neutropenic patients with haematological malignancy and 247 were patients with a normal or raised total white blood cell co...

The complete sequence and comparative analysis of a multidrug- resistance and virulence multireplicon IncFII plasmid pEC302/04 from an extraintestinal pathogenic Escherichia coli EC302/04 indicate extensive diversity of IncFII plasmids

Directory of Open Access Journals (Sweden)

Wing Sze eHo

2016-01-01

Full Text Available Extraintestinal pathogenic Escherichia coli (ExPEC that causes extraintestinal infections often harbor plasmids encoding fitness traits such as resistance and virulence determinants that are of clinical importance. We determined the complete nucleotide sequence of plasmid pEC302/04 from a multidrug-resistant E. coli EC302/04 which was isolated from the tracheal aspirate of a patient in Malaysia. In addition, we also performed comparative sequence analyses of 18 related IncFIIA plasmids to determine the phylogenetic relationship and diversity of these plasmids. The 140,232 bp pEC302/04 is a multireplicon plasmid that bears three replication systems (FII, FIA and FIB with subtype of F2:A1:B1. The plasmid is self-transmissible with a complete transfer region. pEC302/04 also carries antibiotic resistance genes such as blaTEM-1 and a class I integron containing sul1, cml and aadA resistance genes, conferring multidrug resistance (MDR to its host, E. coli EC302/04. Besides, two iron acquisition systems (SitABCD and IutA-IucABCD which are the conserved virulence determinants of ExPEC-colicin V or B and M (ColV/ColBM-producing plasmids were identified in pEC302/04. Multiple toxin-antitoxin (TA-based addiction systems (i.e., PemI/PemK, VagC/VagD, CcdA/CcdB, and Hok/Sok and a plasmid partitioning system, ParAB and PsiAB, which are important for plasmid maintenance were also found.Comparative plasmid analysis revealed only one conserved gene, the repA1 as the core genome, showing that there is an extensive diversity among the IncFIIA plasmids. The phylogenetic relationship of 18 IncF plasmids based on the core regions revealed that ColV/ColBM-plasmids and non-ColV/ColBM plasmids were separated into two distinct groups. These plasmids, which carry highly diverse genetic contents, are also mosaic in nature. The atypical combination of genetic materials, i.e., the MDR- and ColV/ColBM-plasmid-virulence encoding regions in a single ExPEC plasmid is rare but of

The Complete Sequence and Comparative Analysis of a Multidrug-Resistance and Virulence Multireplicon IncFII Plasmid pEC302/04 from an Extraintestinal Pathogenic Escherichia coli EC302/04 Indicate Extensive Diversity of IncFII Plasmids.

Science.gov (United States)

Ho, Wing Sze; Yap, Kien-Pong; Yeo, Chew Chieng; Rajasekaram, Ganeswrie; Thong, Kwai Lin

2015-01-01

Extraintestinal pathogenic Escherichia coli (ExPEC) that causes extraintestinal infections often harbor plasmids encoding fitness traits such as resistance and virulence determinants that are of clinical importance. We determined the complete nucleotide sequence of plasmid pEC302/04 from a multidrug-resistant E. coli EC302/04 which was isolated from the tracheal aspirate of a patient in Malaysia. In addition, we also performed comparative sequence analyses of 18 related IncFIIA plasmids to determine the phylogenetic relationship and diversity of these plasmids. The 140,232 bp pEC302/04 is a multireplicon plasmid that bears three replication systems (FII, FIA, and FIB) with subtype of F2:A1:B1. The plasmid is self-transmissible with a complete transfer region. pEC302/04 also carries antibiotic resistance genes such as bla TEM-1 and a class I integron containing sul1, cml and aadA resistance genes, conferring multidrug resistance (MDR) to its host, E. coli EC302/04. Besides, two iron acquisition systems (SitABCD and IutA-IucABCD) which are the conserved virulence determinants of ExPEC-colicin V or B and M (ColV/ColBM)-producing plasmids were identified in pEC302/04. Multiple toxin-antitoxin (TA)-based addiction systems (i.e., PemI/PemK, VagC/VagD, CcdA/CcdB, and Hok/Sok) and a plasmid partitioning system, ParAB, and PsiAB, which are important for plasmid maintenance were also found. Comparative plasmid analysis revealed only one conserved gene, the repA1 as the core genome, showing that there is an extensive diversity among the IncFIIA plasmids. The phylogenetic relationship of 18 IncF plasmids based on the core regions revealed that ColV/ColBM-plasmids and non-ColV/ColBM plasmids were separated into two distinct groups. These plasmids, which carry highly diverse genetic contents, are also mosaic in nature. The atypical combination of genetic materials, i.e., the MDR- and ColV/ColBM-plasmid-virulence encoding regions in a single ExPEC plasmid is rare but of clinical

Properties of in situ Escherichia coli -D-glucuronidase (GUS ...

African Journals Online (AJOL)

A study of the activity of Escherichia coli -D-glucuronidase (GUS) in polluted stagnant and running water samples was performed with an objective of assessing the viability of a direct marker enzyme assay as a suitable alternative to membrane filtration for the indication of faecal pollution in water intended for drinking ...

Physiological responses of Escherichia coli to far-ultraviolet radiation

International Nuclear Information System (INIS)

Swenson, P.A.

1976-01-01

The following topics are reviewed: photochemical damage to DNA; measurement of cell survival; DNA repair processes and genetics of radiation sensitivity; degradation of DNA and RNA; biochemical and physiological consequences; reactivation of bacteriophage in Escherichia coli cells; filament formation; influence of growth phase on survival after uv irradiation; and post-uv-irradiation treatment

Novel roles for the AIDA adhesin from diarrheagenic Escherichia coli:

DEFF Research Database (Denmark)

Sherlock, Orla; Schembri, Mark; Reisner, A.

2004-01-01

Diarrhea-causing Escherichia coli strains are responsible for numerous cases of gastrointestinal disease and constitute a serious health problem throughout the world. The ability to recognize and attach to host intestinal surfaces is an essential step in the pathogenesis of such strains. AIDA...... binds to mammalian cells. Here, we show that AIDA possesses self-association characteristics and can mediate autoaggregation of E. coli cells. We demonstrate that intercellular AIDA-AIDA interaction is responsible for bacterial autoaggregation. Interestingly, AIDA-expressing cells can interact...

Escherichia coli : host interactions in the pathogenesis of canine pyometra

OpenAIRE

Henriques, Sofia Correia Rosa de Barros

2016-01-01

Tese de Doutoramento em Ciências Veterinárias na Especialidade de Ciências Biológicas e Biomédicas Canine pyometra develops as a result of a complex interaction of etiological and physiopathological factors, such as the virulence and type of the bacteria and the individual host defence mechanisms. Since Escherichia coli is the most common bacterium isolated from uterus of bitches with pyometra, one main objective of this work was to characterize E. coli virulence potential, and...

Distinct inflammatory and cytopathic characteristics of Escherichia coli isolates from inflammatory bowel disease patients

DEFF Research Database (Denmark)

Jensen, Stina Rikke; Mirsepasi-Lauridsen, Hengameh Chloé; Thysen, Anna Hammerich

2015-01-01

Escherichia coli (E. coli) may be implicated in the pathogenesis of inflammatory bowel disease (IBD), as implied from a higher prevalence of mucosa-associated E. coli in the gut of IBD-affected individuals. However, it is unclear whether different non-diarrheagenic E. coli spp. segregate from eac...

Dark fermentative hydrogen and ethanol production from biodiesel waste glycerol using a co-culture of Escherichia coli and Enterobacter sp.

NARCIS (Netherlands)

Maru, B.T.; López, F.; Kengen, S.W.M.; Constantí, M.; Medina, F.

2016-01-01

In previous comparative studies, Enterobacter spH1 was selected as the best hydrogen and ethanol producer (Knothe, 2010). Here, glycerol fermentation was compared between three other strains: Escherichia coli CECT432, Escherichia coli CECT434 and Enterobacter cloacae MCM2/1. E. coli CECT432 was

Incidence of Escherichia coli in black walnut meats.

Science.gov (United States)

Meyer, M T; Vaughn, R H

1969-11-01

Examination of commercially shelled black walnut meats showed inconsistent numbers of total aerobic bacteria, coliforms, and Escherichia coli; variation occurred among different meat sizes and within each meat size. The incidence of E. coli on meats of commercially hulled black walnuts depended on the physical condition of the nuts. Apparently tightly sealed ones contained only a few or none, whereas those with visibly separated sutures and spoiled meats yielded the most. This contamination was in part correlated to a hulling operation. Large numbers of E. coli on the husk of the walnuts contaminated the hulling water, subsequently also contaminating the meats by way of separated sutures. Chlorination of the hulling wash water was ineffective. Attempts were made to decontaminate the walnut meats without subsequent deleterious changes in flavor or texture. A treatment in coconut oil at 100 C followed by removal of excess surface oil by centrifugation was best.

THE ANTIBACTERIAL ACTIVITY OF WATER APPLE LEAVES ACTIVE COMPOUND (Syzygium zeylanicum AGAINST Escherichia coli AND Staphylococcus aureus

Directory of Open Access Journals (Sweden)

- Hamidah

2017-07-01

Full Text Available Escherichia coli is one of the bacteria that cause infections in the human digestive tract such as diarrhea, while Staphylococcus aureus is one of the bacteria that cause infections in the skin injury such as boils and pimples. This study used Syzygium zeylanicum leaves because it has potential as a antibacterial because it contains active compounds. This study aimed was determine the antibacterial activity of the fraction and the active compound in Syzygium zeylanicum leaves against Escherichia coli and Staphylococcus aureus. Research conducted on November 2015 to January 2016. The method used in this research were extraction by maceration, fractionation by liquid fractionation, antibacterial activity test, and determination of minimum inhibitory concentration with the diffusion method and isolation of active compounds by column chromatography method. The bacteria used in this test are Escherichia coli and Staphylococcus aureus. Data are presented in tabular form based on the average value of the inhibition diameter and deviation standard. The results of this research showed the water methanol active fraction against the bacteria that used in this test. The methanol water fraction had obtained one antibacterial compound in bottle 1,3,5 which shows the value of tannin Rf 0,416. The minimum inhibitory concentration of water methanol of water apple leaves is 1000 µg/mL for Escherichia coli and 500 µg/mL for  Staphylococcus aureus. The minimum  inhibitory concentration of the active  compound  to  Escherichia  coli  and  Staphylococcus  aureus  in  500  µg/mL.  The fraction and the active compound of water apple leaves have an antibacterial activity with Escherichia coli and Staphylococcus aureus and the active compound is tannin.

77 FR 58091 - Risk-Based Sampling of Beef Manufacturing Trimmings for Escherichia coli (E. coli) O157:H7 and...

Science.gov (United States)

2012-09-19

... for exposure of carcasses and parts to any contamination or food safety hazard during the removal of... DEPARTMENT OF AGRICULTURE Food Safety and Inspection Service [Docket No. FSIS-2012-0020] Risk-Based Sampling of Beef Manufacturing Trimmings for Escherichia coli (E. coli) O157:H7 and Plans for Beef...

Engineering Escherichia coli for methanol conversion.

Science.gov (United States)

Müller, Jonas E N; Meyer, Fabian; Litsanov, Boris; Kiefer, Patrick; Potthoff, Eva; Heux, Stéphanie; Quax, Wim J; Wendisch, Volker F; Brautaset, Trygve; Portais, Jean-Charles; Vorholt, Julia A

2015-03-01

Methylotrophic bacteria utilize methanol and other reduced one-carbon compounds as their sole source of carbon and energy. For this purpose, these bacteria evolved a number of specialized enzymes and pathways. Here, we used a synthetic biology approach to select and introduce a set of "methylotrophy genes" into Escherichia coli based on in silico considerations and flux balance analysis to enable methanol dissimilation and assimilation. We determined that the most promising approach allowing the utilization of methanol was the implementation of NAD-dependent methanol dehydrogenase and the establishment of the ribulose monophosphate cycle by expressing the genes for hexulose-6-phosphate synthase (Hps) and 6-phospho-3-hexuloisomerase (Phi). To test for the best-performing enzymes in the heterologous host, a number of enzyme candidates from different donor organisms were selected and systematically analyzed for their in vitro and in vivo activities in E. coli. Among these, Mdh2, Hps and Phi originating from Bacillus methanolicus were found to be the most effective. Labeling experiments using (13)C methanol with E. coli producing these enzymes showed up to 40% incorporation of methanol into central metabolites. The presence of the endogenous glutathione-dependent formaldehyde oxidation pathway of E. coli did not adversely affect the methanol conversion rate. Taken together, the results of this study represent a major advancement towards establishing synthetic methylotrophs by gene transfer. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Genes and proteins of Escherichia coli (GenProtEc).

Science.gov (United States)

Riley, M; Space, D B

1996-01-01

GenProtEc is a database of Escherichia coli genes and their gene products, classified by type of function and physiological role and with citations to the literature for each. Also present are data on sequence similarities among E.coli proteins with PAM values, percent identity of amino acids, length of alignment and percent aligned. The database is available as a PKZip file by ftp from mbl.edu/pub/ecoli.exe. The program runs under MS-DOS on IMB-compatible machines. GenProtEc can also be accessed through the World Wide Web at URL http://mbl.edu/html/ecoli.html.

The green alga, Cladophora, promotes Escherichia coli growth and contamination of recreational waters in Lake Michigan.

Science.gov (United States)

Vanden Heuvel, Amy; McDermott, Colleen; Pillsbury, Robert; Sandrin, Todd; Kinzelman, Julie; Ferguson, John; Sadowsky, Michael; Byappanahalli, Muruleedhara; Whitman, Richard; Kleinheinz, Gregory T

2010-01-01

A linkage between Cladophora mats and exceedances of recreational water quality criteria has been suggested, but not directly studied. This study investigates the spatial and temporal association between Escherichia coli concentrations within and near Cladophora mats at two northwestern Lake Michigan beaches in Door County, Wisconsin. Escherichia coli concentrations in water underlying mats were significantly greater than surrounding water (p Cladophora mats had lower E. coli concentrations, but surpassed EPA swimming criteria the majority of sampling days. A significant positive association was found between E. coli concentrations attached to Cladophora and in underlying water (p Cladophora mats from beach areas may improve aesthetic and microbial water quality at affected beaches. These associations and potential natural growth of E. coli in bathing waters call into question the efficacy of using E. coli as a recreational water quality indicator of fecal contaminations.

Escherichia coli clearance after splenic autotransplants

International Nuclear Information System (INIS)

Marques, R.G.; Petroianu, A.; Oliveira, M.B.N.; Bernardo-Filho, M.; Portela, M.C.

2002-01-01

Background: Splenic autotransplantation seems to be the only alternative for preservation of splenic tissue, after total splenectomy. The present study was carried out to analyze Escherichia coli depuration by mononuclear phagocyte system organs after total splenectomy and splenic autotransplantation. Methods: We utilized an experimental model including young and adult Wistar rats, of both sexes, submitted to total splenectomy and splenic autotransplantation. The evaluation method was intravenous inoculation of a suspension of Escherichia coli labeled with technetium-99m. We analyzed bacteria uptake by mononuclear phagocyte system organs and bacteria remnant in the bloodstream. Results: There was no difference between young and adult animals in bacteria uptake by mononuclear phagocyte system organs. In the comparison of groups, it was found out that the mean percent uptake by spleen and liver of animals in the control group was higher than that observed for animals with splenic implants. However, bacteria uptake in the lung was higher in the splenic implant group than in the control group. Although spleen bacteria uptake in the control group animals has been higher than that of animals in the splenic implant group, the remnant bacteria in the bloodstream was similar. Animals submitted to isolated total splenectomy showed higher bacteria remnant in the bloodstream than animals of the control group or the group submitted to total splenectomy combined with splenic autotransplantation. Conclusion: Our results indicate that autogenous splenic implant is efficacious in bacteria depuration in rats, by means of their macrophages phagocytosis. In addition, it does not modify bacteria removal function of liver and lung

Antibiotic Sensitivity Profile of Escherichia coli Isolated from Poultry ...

African Journals Online (AJOL)

A cross sectional study involving 300 cloaca swabs from apparently healthy birds from 8 small-medium scale poultry farms in Ibadan Oyo State was carried out. A total of 201 (67%) Escherichia coli isolates were recovered from the birds and they were subjected to in-vitro antibiotic sensitivity test by agar gel diffusion method.

Complete Genome Sequence of Enterotoxigenic Escherichia coli Siphophage Seurat.

Science.gov (United States)

Doan, Dung P; Lessor, Lauren E; Hernandez, Adriana C; Kuty Everett, Gabriel F

2015-02-26

Enterotoxigenic Escherichia coli (ETEC) is one of the leading causes of diarrhea in developing countries. Bacteriophage therapy has the potential to aid in the prevention and treatment of ETEC-related illness. To that end, we present here the complete genome of ETEC siphophage Seurat and describe its major features. Copyright © 2015 Doan et al.

Effects of substitutions at position 180 in the Escherichia coli RNA ...

Indian Academy of Sciences (India)

Escherichia coli RNA polymerase, two mutant variants of the protein with substitutions for either alanine or glutamic .... promoter signals utilized for in vitro transcription assays and ..... free recombinant protein using a self-cleavable affinity tag.

Escherichia coli as other Enterobacteriaceae: food poisoning and health effects

Science.gov (United States)

Many Escherichia coli strains are harmless, and they are an important commensal in the intestinal microflora; however, pathogenic strains also exist. The pathogenic strains can be divided into diarrhea-inducing strains and strains that reside in the intestines but only cause disease in bodily sites...

Production of jet fuel precursor monoterpenoids from engineered Escherichia coli

DEFF Research Database (Denmark)

Mendez-Perez, Daniel; Alonso-Gutierrez, Jorge; Hu, Qijun

2017-01-01

). FPP biosynthesis diverts the carbon flux from monoterpene production to C15 products and quinone biosynthesis. In this study, we tested a chromosomal mutation of Escherichia coli's native FPP synthase (IspA) to improve GPP availability for the production of monoterpenes using a heterologous mevalonate...

Nature of transforming deoxyribonucleic acid in calcium-treated Escherichia coli

International Nuclear Information System (INIS)

Strike, P.; Humphreys, G.O.; Roberts, R.J.

1979-01-01

A study of the reactivation of ultraviolet-irradiated plasmid and phage deoxyribonucleic acid molecules after transformation into Escherichia coli strains indicated that, when double-stranded deoxyribonucleic acid was used as the donor species, it was taken up without conversion to the single-stranded form

Comparative Genomics of Escherichia coli Strains Causing Urinary Tract Infections

DEFF Research Database (Denmark)

Vejborg, Rebecca Munk; Hancock, Viktoria; Schembri, Mark A.

2011-01-01

The virulence determinants of uropathogenic Escherichia coli have been studied extensively over the years, but relatively little is known about what differentiates isolates causing various types of urinary tract infections. In this study, we compared the genomic profiles of 45 strains from a range...

Effect of phytoplankton on Escherichia coli survival in laboratory microcosms

Science.gov (United States)

Fecal contamination of water sources is an important water quality issue for agricultural irrigation ponds. Escherichia coli is a common microbial indicator used to evaluate recreational and irrigation water quality. Nuisance algae commonly grow in low- or no-flow irrigation water source The objecti...

Kwantitatief gevoeligheidsonderzoek met intra- en extramurale isolaten van Escherichia coli

NARCIS (Netherlands)

de Neeling AJ; de Jong J; Overbeek BP; de Bruin RW; Dessens-Kroon M; van Klingeren B

1990-01-01

Three Dutch laboratories for medical microbiology collected a total number of 1432 strains of Escherichia coli. Of these 995 were obtained from routine samples taken in clinic and policlinic, 290 had been sent spontaneously by general practitioners for microbiological examination and 147 had been

Isolation and epidemiology of multidrug resistant Escherichia coli from goats in Cox's Bazar, Bangladesh

Directory of Open Access Journals (Sweden)

Kamrul Islam

2016-06-01

Conclusion: Presence of MDR E. coli in the studied goats suggest the probable acquisition, development and transmission of MDR E. coli through a number of influencing factors to other animals and potentially to human. [J Adv Vet Anim Res 2016; 3(2.000: 166-172

Emergence of colistin-resistant Escherichia coli clinical isolates harboring mcr-1 in Vietnam.

Science.gov (United States)

Tada, Tatsuya; Nhung, Pham Hong; Shimada, Kayo; Tsuchiya, Mitsuhiro; Phuong, Doan Mai; Anh, Nguyen Quoc; Ohmagari, Norio; Kirikae, Teruo

2017-10-01

The mcr-1 was first detected on a plasmid in colistin-resistant Escherichia coli from livestock and patients in China. We described here the emergence of colistin-resistant E. coli clinical isolates harboring mcr-1 on the chromosomes in Vietnam. To our knowledge, this is the first report of hospital-acquired E. coli isolates harboring mcr-1 in a medical setting in Vietnam. Copyright © 2017. Published by Elsevier Ltd.

Dynamics of Escherichia coli Chromosome Segregation during Multifork Replication

DEFF Research Database (Denmark)

Nielsen, Henrik Jørck; Youngren, Brenda; Hansen, Flemming G.

2007-01-01

Slowly growing Escherichia coli cells have a simple cell cycle, with replication and progressive segregation of the chromosome completed before cell division. In rapidly growing cells, initiation of replication occurs before the previous replication rounds are complete. At cell division, the chro......Slowly growing Escherichia coli cells have a simple cell cycle, with replication and progressive segregation of the chromosome completed before cell division. In rapidly growing cells, initiation of replication occurs before the previous replication rounds are complete. At cell division......, the chromosomes contain multiple replication forks and must be segregated while this complex pattern of replication is still ongoing. Here, we show that replication and segregation continue in step, starting at the origin and progressing to the replication terminus. Thus, early-replicated markers on the multiple......-branched chromosomes continue to separate soon after replication to form separate protonucleoids, even though they are not segregated into different daughter cells until later generations. The segregation pattern follows the pattern of chromosome replication and does not follow the cell division cycle. No extensive...

Complete genome sequences of Escherichia coli strains 1303 and ECC-1470 isolated from bovine mastitis

NARCIS (Netherlands)

Leimbach, Andreas; Poehlein, Anja; Witten, Anika; Scheutz, Flemming; Schukken, Ynte|info:eu-repo/dai/nl/075051907; Daniel, Rolf; Dobrindt, Ulrich

2016-01-01

Escherichia coli is the leading causative agent of acute bovine mastitis. Here, we report the complete genome sequence of E. coli O70:H32 strain 1303, isolated from an acute case of bovine mastitis, and E. coli Ont:Hnt strain ECC-1470, isolated from a persistent infection.

Radiosensitization of Escherichia coli and Salmonella typhi in presence of active compounds

International Nuclear Information System (INIS)

Lacroix, M.; Chiasson, F.; Borsa, J.; Ouattara, B.

2004-01-01

The radiosensitization of Escherichia coli and Salmonella typhi in ground beef was evaluated in the presence of 18 active compounds. Medium fat ground beef (23% fat) was inoculated with E. coli or S. typhi and each active compound was added separately at various concentrations. For E. coli, the most efficient compounds were trans-cinnamaldehyde, thymol and thyme. For S. typhi, the most efficient compounds was trans-cinnamaldehyde, carvacrol and thymol. The addition of tetrasodium pyrophosphate, carvacrol and ascorbic acid had no effect on the irradiation sensitivity of E. coli. For S. typhi, only ascorbic acid had no effect

Radiosensitization of Escherichia coli and Salmonella typhi in presence of active compounds

Energy Technology Data Exchange (ETDEWEB)

Lacroix, M. E-mail: monique.lacroix@inrs-iaf.uquebec.ca; Chiasson, F.; Borsa, J.; Ouattara, B

2004-10-01

The radiosensitization of Escherichia coli and Salmonella typhi in ground beef was evaluated in the presence of 18 active compounds. Medium fat ground beef (23% fat) was inoculated with E. coli or S. typhi and each active compound was added separately at various concentrations. For E. coli, the most efficient compounds were trans-cinnamaldehyde, thymol and thyme. For S. typhi, the most efficient compounds was trans-cinnamaldehyde, carvacrol and thymol. The addition of tetrasodium pyrophosphate, carvacrol and ascorbic acid had no effect on the irradiation sensitivity of E. coli. For S. typhi, only ascorbic acid had no effect.

Toxin production and antibiotic resistances in Escherichia coli isolated from bathing areas along the coastline of the Oslo fjord.

Science.gov (United States)

Charnock, Colin; Nordlie, Anne-Lise; Hjeltnes, Bjarne

2014-09-01

The presence of enterovirulent and/or antibiotic resistant strains of Escherichia coli in recreational bathing waters would represent a clear health issue. In total, 144 E. coli isolated from 26 beaches along the inner Oslo fjord were examined for virulence determinants and resistance to clinically important antibiotics. No isolates possessed the genetic determinants associated with enterotoxigenic strains and none showed the prototypic sorbitol negative, O157:H7 phenotype. A small number (∼1 %) produced alpha-hemolysin. Occurrences and patterns of antibiotic resistances were similar to those of E. coli isolated previously from environmental samples. In total, 6 % of the strains showed one or more clinically relevant resistances and 1.4 % were multi-drug resistant. Microarray analyses suggested that the resistance determinants were generally associated with mobile genetic elements. Resistant strains were not clonally related, and were, furthermore not concentrated at one or a few beach sites. This suggests that these strains are entering the waters at a low rate but in a widespread manner. The study demonstrates that resistant E. coli are present in coastal bathing waters where they can come into contact with bathers, and that the resistance determinants are potentially transferable. Some of the resistances registered in the study are to important antibiotics used in human medicine such as fluoroquinolones. The spread of antibiotic resistant genes, from the clinical setting to the environment, has clear implications with respect to the current management of bacterial infections and the long term value of antimicrobial therapy. The present study is the first of its kind in Norway.

Diarrhoeagenic Escherichia coli are not a significant cause of diarrhoea in hospitalised children in Kuwait

Directory of Open Access Journals (Sweden)

Pacsa Alexander S

2009-03-01

Full Text Available Abstract Background The importance of diarrhoeagenic Escherichia coli (DEC infections in the Arabian Gulf including Kuwait is not known. The prevalence of DEC (enterotoxigenic [ETEC], enteropathogenic [EPEC], enteroinvasive [EIEC], enterohemorrhagic [EHEC] and enteroaggregative [EAEC] was studied in 537 children ≤ 5 years old hospitalised with acute diarrhoea and 113 matched controls from two hospitals during 2005–07 by PCR assays using E. coli colony pools. Results The prevalence of DEC varied from 0.75% for EHEC to 8.4% for EPEC (mostly atypical variety in diarrhoeal children with no significant differences compared to that in control children (P values 0.15 to 1.00. Twenty-seven EPEC isolates studied mostly belonged to non-traditional serotypes and possessed β and θ intimin subtypes. A total of 54 DEC isolates from diarrhoeal children and 4 from controls studied for antimicrobial susceptibility showed resistance for older antimicrobials, ampicillin (0 to 100%, tetracycline (33 to 100% and trimethoprim (22.2 to 100%; 43.1% of the isolates were multidrug-resistant (resistant to 3 or more agents. Six (10.4% DEC isolates produced extended spectrum β-lactamases and possessed genetic elements (blaCTX-M, blaTEM and ISEcp1 associated with them. Conclusion We speculate that the lack of significant association of DEC with diarrhoea in children in Kuwait compared to countries surrounding the Arabian Gulf Region may be attributable to high environmental and food hygiene due to high disposable income in Kuwait.

Molecular prophage typing of avian pathogenic Escherichia coli.

Science.gov (United States)

Kwon, Hyuk-Joon; Seong, Won-Jin; Kim, Jae-Hong

2013-03-23

Escherichia coli prophages confer virulence and resistance to physico-chemical, nutritional, and antibiotic stresses on their hosts, and they enhance the evolution of E. coli. Thus, studies on profiles of E. coli prophages are valuable to understand the population structure and evolution of E. coli pathogenicity. Large terminase genes participate in phage genome packaging and are one of the cornerstones for the identification of prophages. Thus, we designed primers to detect 16 types of large terminase genes and analyzed the genomes of 48 E. coli and Shigella reference strains for the prophage markers. We also investigated the distribution of the 16 prophage markers among 92 avian pathogenic E. coli (APEC) strains. APEC strains were classified into 61 prophage types (PPTs). Each strain was different from the reference strains as measured by the PPTs and from the frequency of each prophage marker. Investigation of the distribution of prophage-related serum resistance (bor), toxin (stx1 and cdtI), and T3SS effector (lom, espK, sopE, nleB, and ospG) genes revealed the presence of bor (44.1%), lom (95.5%) and cdtI (9.1%) in APEC strains with related prophages. Therefore, the molecular prophage typing method may be useful to understand population structure and evolution of E. coli pathogenicity, and further studies on the mobility of the prophages and the roles of virulence genes in APEC pathogenicity may be valuable. Copyright © 2012 Elsevier B.V. All rights reserved.

The enhanced UV-sensitivity of Escherichia coli uvr A crp strain

International Nuclear Information System (INIS)

Skavronskaya, A.G.; Aleshkin, G.I.

1979-01-01

Mutations in genes cya and crp do not affect the UV cell sensitivity of Escherichia coli of wild type in relation to repairs of UV-injuries and UV induced mutations yield. Mutations in gene crp (protein defect of catabolitic activator - cap) result in UV sensitivity decrease of E. coli uvrA strain, imperfect as to the first stage of excision repairs not decreasing the quantity of revertants, induced by the UV-light

Prevalence of Avian Pathogenic Escherichia coli (APEC Clone Harboring sfa Gene in Brazil

Directory of Open Access Journals (Sweden)

Terezinha Knöbl

2012-01-01

Full Text Available Escherichia coli sfa+ strains isolated from poultry were serotyped and characterized by polymerase chain reaction (PCR and amplified fragment length polymorphism (AFLP. Isolates collected from 12 Brazilian poultry farms mostly belonged to serogroup O6, followed by serogroups O2, O8, O21, O46, O78, O88, O106, O111, and O143. Virulence genes associated were: iuc 90%, fim 86% neuS 60%, hly 34%, tsh 28%, crl/csg 26%, iss 26%, pap 18%, and 14% cnf. Strains from the same farm presented more than one genotypic pattern belonging to different profiles in AFLP. AFLP showed a clonal relation between Escherichia coli sfa+ serogroup O6. The virulence genes found in these strains reveal some similarity with extraintestinal E. coli (ExPEC, thus alerting for potential zoonotic risk.

Free water surface constructed wetlands limit the dissemination of extended-spectrum beta-lactamase producing Escherichia coli in the natural environment.

Science.gov (United States)

Vivant, Anne-Laure; Boutin, Catherine; Prost-Boucle, Stéphanie; Papias, Sandrine; Hartmann, Alain; Depret, Géraldine; Ziebal, Christine; Le Roux, Sophie; Pourcher, Anne-Marie

2016-11-01

The fates of Escherichia coli and extended-spectrum beta-lactamase-producing E. coli (ESBL E. coli) were studied over a period of one year in a free water surface constructed wetland (FWS CW) with a succession of open water zones and vegetation ponds (Typha or Phragmites), that received the effluent from a wastewater treatment plant. ESBL E. coli were detected and isolated from all sampling areas of the FWS CW throughout the study period. They represented 1‰ of the total E. coli population regardless of the origin of samples. Two main factors affected the log removal of E. coli and of ESBL E. coli: the season and the presence of vegetation. Between the inlet and the outlet of the FWS CW, the log removal of E. coli ranged from 1.5 in the warmer season (summer and fall) to 3.0 in the colder season (winter and spring). The concentrations of E. coli decreased significantly in the vegetated areas during the colder season, but increased in the warmer season, suggesting an effect of the plant growth stage on the survival of E. coli. Among the 369 ESBL E. coli isolates collected during our study, 84% harbored the CTX-M-ESBL type and 55.3% carried bla genes on plasmid DNA. Furthermore, 93% of the ESBL E. coli isolates were multidrug resistant but the proportion of resistant strains did not change significantly along the FWS CW. ESBL E. coli were characterized by MLST analysis using the 7 genes based Achtman Scheme. ESBL E. coli isolated from water, sediments, roots and feces of myocastors collected in the FWS CW and in the recipient river were genotypically related, suggesting persistence and circulation of the ESBL producing E. coli throughout the FWS CW and in the receiving river. Overall, these observations show that FWS CW could be an efficient treatment for ESBL E. coli disinfection of wastewater and could limit their dissemination in the aquatic environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modeling base excision repair in Escherichia coli bacterial cells

International Nuclear Information System (INIS)

Belov, O.V.

2011-01-01

A model describing the key processes in Escherichia coli bacterial cells during base excision repair is developed. The mechanism is modeled of damaged base elimination involving formamidopyrimidine DNA glycosylase (the Fpg protein), which possesses several types of activities. The modeling of the transitions between DNA states is based on a stochastic approach to the chemical reaction description

Prevalence of Antibiotic-Resistant Strains of Escherichia coli in ...

African Journals Online (AJOL)

A total of six bacteria species Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, Klebsiella pneumonia, Staphylococcus aureus, Enterobacter aerogenes were ... Énumération de nombre de plaque standard a été effectuée par la méthode de la plaque de propagation sur des échantillons d'eau dilués en série.

Genes under positive selection in Escherichia coli

DEFF Research Database (Denmark)

Petersen, Lise; Bollback, Jonathan P; Dimmic, Matt

2007-01-01

We used a comparative genomics approach to identify genes that are under positive selection in six strains of Escherichia coli and Shigella flexneri, including five strains that are human pathogens. We find that positive selection targets a wide range of different functions in the E. coli genome......, including cell surface proteins such as beta barrel porins, presumably because of the involvement of these genes in evolutionary arms races with other bacteria, phages, and/or the host immune system. Structural mapping of positively selected sites on trans-membrane beta barrel porins reveals...... that the residues under positive selection occur almost exclusively in the extracellular region of the proteins that are enriched with sites known to be targets of phages, colicins, or the host immune system. More surprisingly, we also find a number of other categories of genes that show very strong evidence...

Control analysis of the dependence of Escherichia coli physiology on the H⁺ -ATPase

DEFF Research Database (Denmark)

Jensen, Peter Ruhdal; Michelsen, Ole; Westerhoff, Hans V.

1993-01-01

The H+-ATPase plays a central role in Escherichia coli free-energy transduction and hence in E. coli physiology. We here investigate the extent to which this enzyme also controls the growth rate, growth yield, and respiratory rate of E. coli. We modulate the expression of the atp operon and deter...

DNA supercoiling depends on the phosphorylation potential in Escherichia coli

DEFF Research Database (Denmark)

Van Workum, M.; van Dooren, S.J.M; Oldenburg, N

1996-01-01

ATP/ADP ratios were varied in different ways and the degree of negative supercoiling was determined in Escherichia coli. Independent of whether the ATP/ADP ratio was reduced by a shift to anaerobic conditions, by addition of protonophore (dinitrophenol) or by potassium cyanide addition, DNA super...

Differential expression of the Escherichia coli autoaggregation factor antigen 43

DEFF Research Database (Denmark)

Schembri, Mark; Hjerrild, Louise; Gjermansen, Morten

2003-01-01

Antigen 43 (Ag43) is a self-recognizing surface adhesin found in most Escherichia coli strains. Due to its excellent cell-to-cell aggregation characteristics, Ag43 expression confers clumping and fluffing of cells and promotes biofilm formation. Ag43 expression is repressed by the cellular redox...

iML1515, a knowledgebase that computes Escherichia coli traits

DEFF Research Database (Denmark)

Monk, Jonathan M.; Lloyd, Colton J.; Brunk, Elizabeth

2017-01-01

To the Editor: Extracting knowledge from the many types of big data produced by high-throughput methods remains a challenge, even when data are from Escherichia coli, the best characterized bacterial species. Here, we present iML1515, the most complete genome-scale reconstruction of the metabolic...

Decolorization of dyes by recombinase CotA from Escherichia coli ...

African Journals Online (AJOL)

The CotA laccase could efficiently decolorize anthraquinone and azo dyes in 24 h. The decolourization capacity of this recombinant laccase suggested that it could be a useful biocatalyst for the treatment of dye-containing effluents. Key words: Recombinant CotA laccase, Escherichia coli, purification, dye decolorization.

Search for Enterohaemorrhagic Escherichia coli O157:H7 and ...

African Journals Online (AJOL)

Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 and Salmonella enterica are important zoonotic bacteria responsible for enteric infections in humans. The present study investigated the possible role of kittens in the zoonotic transmission of antimicrobial resistant EHEC O157 and Salmonella enterica to human using ...

Molecular characterization of the Escherichia coli asymptomatic bacteriuria strain 83972

DEFF Research Database (Denmark)

Klemm, Per; Hancock, Viktoria; Ulett, G.C.

2006-01-01

Escherichia coli 83972 is a clinical asymptomatia bacteriuric isolate that is able to colonize the human urinary bladder without inducing an immune response. Here we demonstrate that one of the mechanisms by which this strain has become attenuated is through the mutation of its genes encoding type...

Detection of Escherichia Coli O157:H7 in Fecal Samples in Meat Goats

Science.gov (United States)

Mobley, Ray; Madden, Uford; Brooks-Walter, Alexis

2004-01-01

Studies have reported the isolation of Escherichia coli (E. coli)O157:H7 from pork, lamb and poultry products, and from other animals including deer, horses, dogs, birds and humans. There is limited or no information on the presence of the organism in goats. The objectives of this study were to determine if E. coli O157:H7 was naturally occurring…

Loop-mediated isothermal amplification assay for rapid detection of common strains of Escherichia coli.

Science.gov (United States)

Hill, Joshua; Beriwal, Shilpa; Chandra, Ishwad; Paul, Vinod K; Kapil, Aarti; Singh, Tripti; Wadowsky, Robert M; Singh, Vinita; Goyal, Ankur; Jahnukainen, Timo; Johnson, James R; Tarr, Phillip I; Vats, Abhay

2008-08-01

We developed a highly sensitive and specific LAMP assay for Escherichia coli. It does not require DNA extraction and can detect as few as 10 copies. It detected all 36 of 36 E. coli isolates and all 22 urine samples (out of 89 samples tested) that had E. coli. This assay is rapid, low in cost, and simple to perform.

Escherichia coli ST131, an Intriguing Clonal Group

Science.gov (United States)

Bertrand, Xavier; Madec, Jean-Yves

2014-01-01

SUMMARY In 2008, a previously unknown Escherichia coli clonal group, sequence type 131 (ST131), was identified on three continents. Today, ST131 is the predominant E. coli lineage among extraintestinal pathogenic E. coli (ExPEC) isolates worldwide. Retrospective studies have suggested that it may originally have risen to prominence as early as 2003. Unlike other classical group B2 ExPEC isolates, ST131 isolates are commonly reported to produce extended-spectrum β-lactamases, such as CTX-M-15, and almost all are resistant to fluoroquinolones. Moreover, ST131 E. coli isolates are considered to be truly pathogenic, due to the spectrum of infections they cause in both community and hospital settings and the large number of virulence-associated genes they contain. ST131 isolates therefore seem to contradict the widely held view that high levels of antimicrobial resistance are necessarily associated with a fitness cost leading to a decrease in pathogenesis. Six years after the first description of E. coli ST131, this review outlines the principal traits of ST131 clonal group isolates, based on the growing body of published data, and highlights what is currently known and what we need to find out to provide public health authorities with better information to help combat ST131. PMID:24982321

Lethality prediction for Escherichia coli 0157:H7 and Uropathogenic E. coli in ground chicken treated with high pressure processing and trans-cinnamaldehyde

Science.gov (United States)

Pathogenic Escherichia coli, intestinal (O157:H7) as well as extraintestinal types (Uropathogenic E. coli (UPEC)) are commonly found in many foods including chicken meat. In this study we compared the resistance of E. coli O157:H7 to UPEC in chicken meat under the stresses of high hydrostatic pressu...

Application of swine manure on agricultural fields contributes to extended-spectrum β-lactamase-producing Escherichia coli spread in Tai’an, China

Directory of Open Access Journals (Sweden)

Lili eGao

2015-04-01

Full Text Available The prevalence of extended-spectrum beta-lactamase (ESBL-producing Escherichia coli (E. coli is increasing rapidly in both hospital environments and animal farms. A lot of animal manure has been directly applied into arable fields in the developing countries. But the impact of ESBL-positive bacteria from animal manure on the agricultural fields is sparse, especially in the rural regions of Tai’an, China. Here, we collected 29, 3, and 10 ESBL-producing E. coli from pig manure, compost, and soil samples, respectively. To track ESBL-harboring E. coli from agricultural soil, these isolates of different sources were analyzed with regard to antibiotic resistance profiles, ESBL genes, plasmid replicons, and enterobacterial repetitive intergenic consensus (ERIC-polymerase chain reaction (PCR typing. The results showed that all the isolates exhibited multi-drug resistance. CTX-M gene was the predominant ESBL gene in the isolates from pig farm samples (30/32, 93.8% and soil samples (7/10, 70.0%, but no SHV gene was detected. 25 isolates contained the IncF-type replicon of plasmid, including 18 strains (18/32, 56.3% from the pig farm and 7 (7/10, 70.0% from the soil samples. ERIC-PCR demonstrated that 3 isolates from the soil had above 90% genetic similarity with strains from pig farm samples. In conclusion, application of animal manure carrying drug-resistant bacteria on agricultural fields is a likely contributor to antibiotic resistance gene spread.

Detection of CTX-M-15 Among Uropathogenic Escherichia coli Isolated from Five Major Hospitals in Tripoli, Libya

Directory of Open Access Journals (Sweden)

Abdulaziz Zorgani1*,

2017-07-01

Full Text Available Objectives: Multidrug resistance (MDR and emergence of extended-spectrum β-lactamases (ESBLs among uropathogenic Escherichia coli have been reported worldwide, but there was no information on the detection of blaCTX-M-15 in major teaching hospitals in Libya. The aim of the study was to investigate the occurrence of CTX-M-15 β-lactamases producers isolated from five teaching hospitals in Tripoli, Libya. Methods: A total of 346 urine samples were collected from hospitalized patients in five teaching hospitals with a diagnosis of urinary tract infection (UTI. Phenotypic confirmation of ESBLs was confirmed by E-test strip; all ESBL-producing E. coli isolates were screened for the blaCTX-M-15 gene. Results: The distribution of ESBL-producing E. coli varied among the five hospitals. The highest proportion was identified in Tripoli Medical Centre (67.6%. There were extremely high proportions of isolates resistant to ceftriaxone, cefepime, and ceftazidime (93.0–100.0% among ESBL producers compared to non-ESBL producers (2.2–4.7%. MDR was detected in 22.2% of isolates. The majority of isolates (85.9% in which blaCTX-M-15 was identified were ESBL producers. There was a correlation (p < 0.001 between expression of CTX-M-15 and resistance to ceftazidime. Conclusions: The isolation of MDR ESBL-producing uropathogens expressing the CTX-M-15 gene will limit the choices clinicians have to treat their patients with UTIs. Continued surveillance and implementation of efficient infection control measures are required.

Interaction of Escherichia coli with growing salad spinach plants.

Science.gov (United States)

Warriner, Keith; Ibrahim, Faozia; Dickinson, Matthew; Wright, Charles; Waites, William M

2003-10-01

In this study, the interaction of a bioluminescence-labeled Escherichia coli strain with growing spinach plants was assessed. Through bioluminescence profiles, the direct visualization of E. coli growing around the roots of developing seedlings was accomplished. Subsequent in situ glucuronidase (GUS) staining of seedlings confirmed that E. coli had become internalized within root tissue and, to a limited extent, within hypocotyls. When inoculated seeds were sown in soil microcosms and cultivated for 42 days, E. coli was recovered from the external surfaces of spinach roots and leaves as well as from surface-sterilized roots. When 20-day-old spinach seedlings (from uninoculated seeds) were transferred to soil inoculated with E. coli, the bacterium became established on the plant surface, but internalization into the inner root tissue was restricted. However, for seedlings transferred to a hydroponic system containing 10(2) or 10(3) CFU of E. coli per ml of the circulating nutrient solution, the bacterium was recovered from surface-sterilized roots, indicating that it had been internalized. Differences between E. coli interactions in the soil and those in the hydroponic system may be attributed to greater accessibility of the roots in the latter model. Alternatively, the presence of a competitive microflora in soil may have restricted root colonization by E. coli. The implications of this study's findings with regard to the microbiological safety of minimally processed vegetables are discussed.

Volunteer Challenge With Enterotoxigenic Escherichia coli That Express Intestinal Colonization Factor Fimbriae CS17 and CS19

Science.gov (United States)

2011-07-01

Serotype was determined by classic serological methods at the Universidad Nacional Aut6noma de Mexico [UNAMl. H- indrcates non-motility. b CF...Levine MM, Merson MM. Serologic differentiation between antitoxin responses to infection with Vibrio cholerae and enterotoxin-producing Escherichia coli...prototype cholera B subunit-colonization factor antigen cnterotoxigenic Escherichia coli vaccine. Vaccine 1993; 1[:929-34. 15. Levine MM, Nalin DR

Resistência a antimicrobianos de Escherichia coli isolada de dejetos suínos em esterqueiras Antibiotic-resistance of Escherichia coli isolates from stored pig slurry

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F.F.P. Silva

2008-06-01

Full Text Available The antimicrobial resistance of 96 Escherichia coli strains isolated from a stabilization pond system on a pig-breeding farm was evaluated. Strains were tested for their resistance against 14 antimicrobial using the agar diffusion method. E. coli strains showed resistance to tetracycline (82.3%, nalidixic acid (64%, ampicilin (41%, sulfamethoxazole/trimethoprin (36%, sulfonamide (34%, cloranphenicol (274%, ciprofloxacin (19%, cefaclor (16%, streptomicyn (7.3%, neomicyn (1%, amoxacilin/ clavulanic acid (1%, and amikacin (1%. No resistance was observed to gentamicin and tobramycin, and 37.5% of E. coli strains were resistant to four or more antimicrobials. The multiresistance pattern was found in strains isolated during all sampled period. Strains showed a high variability in the antimicrobial resistance pattern.

Ciprofloxacin causes persister formation by inducing the TisB toxin in Escherichia coli.

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Tobias Dörr

2010-02-01

Full Text Available Bacteria induce stress responses that protect the cell from lethal factors such as DNA-damaging agents. Bacterial populations also form persisters, dormant cells that are highly tolerant to antibiotics and play an important role in recalcitrance of biofilm infections. Stress response and dormancy appear to represent alternative strategies of cell survival. The mechanism of persister formation is unknown, but isolated persisters show increased levels of toxin/antitoxin (TA transcripts. We have found previously that one or more components of the SOS response induce persister formation after exposure to a DNA-damaging antibiotic. The SOS response induces several TA genes in Escherichia coli. Here, we show that a knockout of a particular SOS-TA locus, tisAB/istR, had a sharply decreased level of persisters tolerant to ciprofloxacin, an antibiotic that causes DNA damage. Step-wise administration of ciprofloxacin induced persister formation in a tisAB-dependent manner, and cells producing TisB toxin were tolerant to multiple antibiotics. TisB is a membrane peptide that was shown to decrease proton motive force and ATP levels, consistent with its role in forming dormant cells. These results suggest that a DNA damage-induced toxin controls production of multidrug tolerant cells and thus provide a model of persister formation.

Extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae in local and imported poultry meat in Ghana.

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Eibach, Daniel; Dekker, Denise; Gyau Boahen, Kennedy; Wiafe Akenten, Charity; Sarpong, Nimako; Belmar Campos, Cristina; Berneking, Laura; Aepfelbacher, Martin; Krumkamp, Ralf; Owusu-Dabo, Ellis; May, Jürgen

2018-04-01

Antibiotic use in animal husbandry has raised concerns on the spread of resistant bacteria. Currently animal products are traded globally with unprecedented ease, which has been challenging the control of antimicrobial resistance. This study aims to detect and characterize extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae from imported and locally produced poultry products sold in Ghana. Local and imported chicken meat was collected from 94 stores and markets throughout Kumasi (Ghana) and cultured on selective ESBL screening agar. Phenotypic ESBL-producing E. coli and K. pneumoniae isolates were confirmed by combined disc test and further characterized by antibiotic susceptibility testing, amplification of the bla CTX-M , bla TEM and bla SHV genes as well as multilocus sequence typing (MLST) and linked to the country of origin. Out of 200 meat samples, 71 (36%) samples revealed 81 ESBL-producing isolates (46 E. coli and 35 K. pneumoniae), with 44% (30/68) of local poultry and 31% (41/132) of imported products being contaminated. Most ESBL-producing isolates harboured the bla CTX-M-15 gene (61/81, 75%) and the dominant Sequence Types (ST) were ST2570 (7/35, 20%) among K. pneumoniae and ST10 (5/46, 11%) among E. coli. High numbers of ESBL-producing bacteria, particularly on local but also imported poultry meat, represent a potential source for human colonization and infection as well as spread within the community. Surveillance along the poultry production-food-consumer chain would be a valuable tool to identify sources of emerging multidrug resistant pathogens in Ghana. Copyright © 2018 Elsevier B.V. All rights reserved.

GENETIC CONTROL OF RESTRICTION AND MODIFICATION IN ESCHERICHIA COLI1

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Boyer, Herbert

1964-01-01

Boyer, Herbert (Yale University, New Haven, Conn.). Genetic control of restriction and modification in Escherichia coli. J. Bacteriol. 88:1652–1660. 1964.—Bacterial crosses with K-12 strains of Escherichia coli as Hfr donors (Hfr Hayes, Hfr Cavalli, and Hfr P4X-6) and B/r strains of E. coli as F− recipients were found to differ from crosses between K-12 Hfr donors and K-12 F− recipients in two ways: (i) recombinants (leu, pro, lac, and gal) did not appear at discrete time intervals but did appear simultaneously 30 min after matings were initiated, and (ii) the linkage of unselected markers to selected markers was reduced. Integration of a genetic region linked to the threonine locus of K-12 into the B/r genome resulted in a hybrid which no longer gave anomalous results in conjugation experiments. A similar region of the B strain was introduced into the K-12 strain, which then behaved as a typical B F− recipient. These observations are interpreted as the manifestation of host-controlled modification and restriction on the E. coli chromosome. This was verified by experiments on the restriction and modification of the bacteriophage lambda, F-lac, F-gal, and sex-factor, F1. It was found that the genetic region that controlled the mating responses of the K-12 and B/r strains also controlled the modification and restriction properties of these two strains. The genes responsible for the restricting and modifying properties of the K-12 and B strains of E. coli were found to be allelic, linked to each other, and linked to the threonine locus. PMID:14240953

Surface display of Salmonella epitopes in Escherichia coli and Staphylococcus carnosus.

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Nhan, Nguyen Thanh; Gonzalez de Valdivia, Ernesto; Gustavsson, Martin; Hai, Truong Nam; Larsson, Gen

2011-04-11

Salmonella enterica serotype Enteritidis (SE) is considered to be one of the most potent pathogenic Salmonella serotypes causing food-borne disease in humans. Since a live bacterial vaccine based on surface display of antigens has many advantages over traditional vaccines, we have studied the surface display of the SE antigenic proteins, H:gm and SefA in Escherichia coli by the β-autotransporter system, AIDA. This procedure was compared to protein translocation in Staphylococcus carnosus, using a staphylococci hybrid vector earlier developed for surface display of other vaccine epitopes. Both SefA and H:gm were translocated to the outer membrane in Escherichia coli. SefA was expressed to full length but H:gm was shorter than expected, probably due to a proteolytic cleavage of the N-terminal during passage either through the periplasm or over the membrane. FACS analysis confirmed that SefA was facing the extracellular environment, but this could not be conclusively established for H:gm since the N-terminal detection tag (His6) was cleaved off. Polyclonal salmonella antibodies confirmed the sustained antibody-antigen binding towards both proteins. The surface expression data from Staphylococcus carnosus suggested that the H:gm and SefA proteins were transported to the cell wall since the detection marker was displayed by FACS analysis. Apart from the accumulated knowledge and the existence of a wealth of equipment and techniques, the results indicate the selection of E. coli for further studies for surface expression of salmonella antigens. Surface expression of the full length protein facing the cell environment was positively proven by standard analysis, and the FACS signal comparison to expression in Staphylococcus carnosus shows that the distribution of the surface protein on each cell was comparatively very narrow in E. coli, the E. coli outer membrane molecules can serve as an adjuvant for the surface antigenic proteins and multimeric forms of the SefA protein

The lon gene and photoprotection in Escherichia coli K-12

International Nuclear Information System (INIS)

Waksman, G.; Thomas, G.; Favre, A.

1984-01-01

Photoprotection, i.e. the increased resistance of the cells preilluminated with near ultraviolet light (300-380 nm) to the lethal action of 254nm radiations requires either an integrated prophage or a recA mutation in Escherichia coli K12 strains. Significant photoprotection occurs in an Escherichia coli K12 recA + cell containing the lon allele responsible for filamentous growth after 254nm irradiation. The Fil phenotype can be suppressed by the sfiA or sfiB suppressor genes. Since the E. coli K12 recA + lon sfiB strain exhibits no more photoprotection, it is concluded that in lon strains photoprotection is due to the abolition of the 254nm induced filamentation by the near ultraviolet treatment. In addition, near ultraviolet illumination of the cells leads to a severe restriction of the bulk protein synthesis. This effect is observed only in nuv + cells that contain 4-thiouridine the chromophore responsible for photoprotection. It is proposed that in lon (lysogenic strains) photoprotection is due to prevention of the SOS response. During the growth lag, the low residual level of protein synthesis does not allow the induction of the SOS response and accordingly prevents filamentation (the lytic cycle). (author)

Efficient Extracellular Expression of Phospholipase D in Escherichia Coli with an Optimized Signal Peptide

Science.gov (United States)

Yang, Leyun; Xu, Yu; Chen, Yong; Ying, Hanjie

2018-01-01

New secretion vectors containing the synthetic signal sequence (OmpA’) was constructed for the secretory production of recombinant proteins in Escherichia coli. The E. coli Phospholipase D structural gene (Accession number:NC_018658) fused to various signal sequence were expressed from the Lac promoter in E. coli Rosetta strains by induction with 0.4mM IPTG at 28°C for 48h. SDS-PaGe analysis of expression and subcellular fractions of recombinant constructs revealed the translocation of Phospholipase D (PLD) not only to the medium but also remained in periplasm of E. coli with OmpA’ signal sequence at the N-terminus of PLD. Thus the study on the effects of various surfactants on PLD extracellular production in Escherichia coli in shake flasks revealed that optimal PLD extracellular production could be achieved by adding 0.4% Triton X-100 into the medium. The maximal extracellular PLD production and extracellular enzyme activity were 0.23mg ml-1 and 16U ml-1, respectively. These results demonstrate the possibility of efficient secretory production of recombinant PLD in E. coli should be a potential industrial applications.

Postgenomics Characterization of an Essential Genetic Determinant of Mammary Pathogenic Escherichia coli.

Science.gov (United States)

Blum, Shlomo E; Goldstone, Robert J; Connolly, James P R; Répérant-Ferter, Maryline; Germon, Pierre; Inglis, Neil F; Krifucks, Oleg; Mathur, Shubham; Manson, Erin; Mclean, Kevin; Rainard, Pascal; Roe, Andrew J; Leitner, Gabriel; Smith, David G E

2018-04-03

Escherichia coli are major bacterial pathogens causing bovine mastitis, a disease of great economic impact on dairy production worldwide. This work aimed to study the virulence determinants of mammary pathogenic E. coli (MPEC). By whole-genome sequencing analysis of 40 MPEC and 22 environmental ("dairy-farm" E. coli [DFEC]) strains, we found that only the fec locus ( fecIRABCDE ) for ferric dicitrate uptake was present in the core genome of MPEC and that it was absent in DFEC genomes ( P price of dairy products on supermarket shelves and the financial hardships suffered by dairy farmers. Mastitis is also the leading reason for the use of antibiotics in dairy farms. Good farm management practices in many countries have dramatically reduced the incidence of contagious mastitis; however, the problems associated with the incidence of environmental mastitis caused by bacteria such as Escherichia coli have proven intractable. E. coli bacteria cause acute mastitis, which affects the health and welfare of cows and in extreme cases may be fatal. Here we show for the first time that the pathogenicity of E. coli causing mastitis in cows is highly dependent on the fecIRABCDE ferric citrate uptake system that allows the bacterium to capture iron from citrate. The Fec system is highly expressed during infection in the bovine udder and is ubiquitous in and necessary for the E. coli bacteria that cause mammary infections in cattle. These results have far-reaching implications, raising the possibility that mastitis may be controllable by targeting this system. Copyright © 2018 Blum et al.

DNA turnover and strand breaks in Escherichia coli