Should asymptomatic bacteriuria be screened in pregnancy?

PubMed

Uncu, Y; Uncu, G; Esmer, A; Bilgel, N

2002-01-01

The incidence of asymptomatic bacteriuria is reported as 2-14% during pregnancy. Fetal and maternal complications like acute pyelonephritis, hypertension, anemia, preterm labor, low-birth-weight infants and intrauterine growth retardation can be expected. The purpose of this study was to determine the incidence of asymptomatic bacteriuria during pregnancy and its relation to pregnancy complications. The study involved 270 pregnant women up to 32 gestational weeks during a 9-month period. At the initial visit, they were screened with urine culture in order to detect asymptomatic bacteriuria. A control group was formed in a retrospective manner from the first day of the study with 186 pregnant women who delivered in our clinic and who were not screened for asymptomatic bacteriuria. The incidence of asymptomatic bacteriuria was 9.31%. Escherichia coli accounted for 79%, which was the most frequent of the isolates. We observed recurrence and had to apply treatment again to 21.7% of the women. The sensitivity, specificity, positive predictive and negative predictive values of leucocyturia as a screening test for asymptomatic bacteriuria were 91.3%, 83.6%, 45.6% and 98.5%, respectively. We diagnosed preterm labor in six of 23 (26%) with asymptomatic bacteriuria and 16 in 163 (9.3%) women in the urine culture negative group. The ratio acute pyelonephritis in the group which was routinely screened and treated for asymtomatic bacteriuria was 0.5% while the prevalence was 2.1% in the nonscreened group. Considering the relatively high incidence of asymptomatic bacteriuria during pregnancy and the relevant complications, we propose to screen and treat asymptomatic bacteriuria routinely in all pregnant women.

Asymptomatic bacteriuria in puppies with canine parvovirus infection: a cohort study.

PubMed

Koutinas, A F; Heliadis, N; Saridomichelakis, M N; Leontides, L; Terpsidis, K; Christodoulou, C

1998-10-01

This study aimed to investigate the possible association between canine parvoviral enteritis and asymptomatic bacteriuria. Forty-three puppies that were admitted to the outpatient service of the Animal Medical Clinic with clinical signs compatible with parvoviral enteritis formed the exposed group. The clinical diagnosis was subsequently confirmed by a positive fecal ELISA test (CITE test: IDDEX Lab., Westbrook, ME). Twenty-three (53.5%) of these puppies were males and 20 (46.5%) were females. Their age ranged from 1.5 to 5.5 months. Forty-eight clinically normal and age-matched puppies, that had been admitted to the clinic for vaccinations and had a negative result in the aforementioned ELISA test, were randomly selected to form the unexposed group. Urine samples were collected by antebupic cystocentesis from all puppies and submitted for bacterial culture. In the parvovirus exposed group, 11 of 43 puppies had detectable bacteriuria. The isolates were Escherichia coli alone (8/11-72.7%) Staphylococcus aureus alone (1/11-9.1%) and mixed cultures of E. coli and S. epidermitis (2/11-18.2%). In the unexposed group there were three puppies with detectable bacteriuria, one isolate each of E. coli, Enterococcus durans and Corynebacterium spp. Puppies with parvoviral enteritis had five (95% CI: 1.3-19.8) times higher odds of developing asymptomatic bacteriuria than puppies without the disease. The observed increased risk of asymptomatic bacteriuria among puppies with parvoviral enteritis was probably due to the fecal contamination of the external genitalia and the neutropenia these puppies exhibited.

Comparison of Asymptomatic Bacteriuria Escherichia coli Isolates from Healthy Individuals versus Those from Hospital Patients Shows that Long-Term Bladder Colonization Selects for Attenuated Virulence Phenotypes

PubMed Central

Salvador, Ellaine; Wagenlehner, Florian; Köhler, Christian-Daniel; Mellmann, Alexander; Hacker, Jörg; Svanborg, Catharina

2012-01-01

Asymptomatic bacteriuria (ABU) is a condition where bacteria stably colonize the urinary tract, in a manner closely resembling commensalism at other mucosal sites. The patients carry >105 CFU/ml for extended periods of time and rarely develop symptoms. Contrasting the properties of ABU strains to those of uropathogenic isolates causing symptomatic infection is therefore highly relevant to understand mechanisms of bacterial adaptation. The prototype ABU strain Escherichia coli 83972 has a smaller genome than uropathogenic E. coli (UPEC) strains with deletions or point mutations in several virulence genes, suggesting that ABU strains undergo a programmed reductive evolution within human hosts. This study addressed if these observations can be generalized. Strains causing ABU in outpatients or hospitalized patients after catheterization or other invasive procedures were compared to commensal E. coli isolates from the intestinal flora of healthy individuals. Notably, clonal complex 73 (CC73) was a prominent phylogenetic lineage dominated by ABU isolates. ABU isolates from outpatients and hospitalized patients had a similar overall virulence gene repertoire, which distinguished them from many commensals, but typical UPEC virulence genes were less frequently attenuated in hospital strains than in outpatient strains or commensals. The decreased virulence potential of outpatient ABU isolates relative to that of ABU strains from hospitalized patients supports the hypothesis that loss of expression or decay of virulence genes facilitates long-term carriage and adaptation to host environments. PMID:22104113

Prevalence of asymptomatic bacteriuria among pregnant women in Benin City, Nigeria.

PubMed

Akerele, J; Abhulimen, P; Okonofua, F

2001-03-01

A semi-quantitative screening for asymptomatic bacteriuria was carried out in the first trimester of 500 consecutive pregnant women in Benin City. The purpose was to provide baseline data and rational therapy for asymptomatic bacteriuria in pregnant women. Of the 500 women screened, 433 clinical specimens showed significant bacteriuria, representing an incidence of 86.6%. Of this number, 38 (7.4%) were of mixed bacterial colonies while 395 (91%) were of single bacterial colonies. Staphylococcus aureus (29.8%), Escherichia coli (29.1%) and Klebsiella pneumoniae (21.5%) were the most frequently isolated pathogens. The high incidence of asymptomatic bacteriuria in pregnancy correlated significantly (P < 0.05) with the observed high proportion of pyuria. On average, sensitivity of the pathogens was ciprofloxacin 99.7%; ceftazidime 81.6%; co-trimoxazole 79.4%; augmentin 71.4%; nalidixic acid 61.7%; nitrofurantoin 61.%; gentamycin 56.9% and ampicillin 25.4%. S. aureus was most sensitive, while Proteus mirabilis was least sensitive among the pathogens. Rational therapy of asymptomatic bacteriuria in pregnant women may prevent associated risks such as pyelonephritis and pre-eclampsia.

Detection of bacteriuria and bacteremia in newborn calves by a catalase-based urine test.

PubMed

Raboisson, D; Clément, J; Queney, N; Lebreton, P; Schelcher, F

2010-01-01

Bacteremia occurs frequently in newborn calves. The predictive value of clinical signs is low, suggesting the use of calf-side diagnostic tests. To investigate testing of urine catalase activity (Uriscreen test) for bacteriuria and bacteremia detection. Five colostrum-free calves and 3 colostrum-fed control calves. Controlled experimental trial. Colostrum-free calves were inoculated PO with Escherichia coli O78+. A clinical score was established to define the onset of the illness. Blood and urine (cystocentesis) samplings and cultures, and Uriscreen tests, were performed 4-6 times from inoculation to death. Three control calves received the same management as 3 inoculated calves, but with colostrum and without inoculation. Bacteremia was demonstrated in all of the inoculated colostrum-free calves and in none of the control calves. The E. coli O78+ strain, E. coli, and Klebsiella spp. were recovered from 4/5, 5/5, and 2/5 inoculated colostrum-free calves, respectively. Urine cultures were negative for the 2 groups at the start of the experiment; 5/5 colostrum-deprived inoculated calves were positive for E. coli thereafter whereas 3/3 controls remained negative. Concordance of Uriscreen tests with bacteremia and bacteriuria was 0.86 and 0.88, respectively. Kappa value of agreement between Uriscreen and bacteremia and bacteriuria was 0.73 and 0.76, respectively. Sensitivity of Uriscreen for bacteremia and bacteriuria was 80.0 and 86.6%, respectively, and specificity was 92.8 and 88.8%, respectively. The results suggest that Uriscreen can be used for detection of bacteremia in neonatal calves in connection with a constant bacteriuria. Copyright © 2010 by the American College of Veterinary Internal Medicine.

A preliminary assessment of asymptomatic bacteriuria of pregnancy in brunei darussalam.

PubMed

Muharram, Siti Hanna; Ghazali, Siti Nur Bazilah; Yaakub, Hajah Roselina; Abiola, Oduola

2014-03-01

Asymptomatic bacteriuria describes a condition in which urine culture reveals a significant growth of pathogenic bacteria, specifically greater than 10(5) of colony-forming units per millilitre of urine. It has a direct bearing on the health of a pregnant woman, her pregnancy and consequently the foetus. Thus, this study investigated the prevalence of asymptomatic bacteriuria of pregnancy in Raja Isteri Pengiran Anak Saleha (RIPAS) Hospital, the premiere tertiary hospital in Brunei Darussalam. A total of 170 pregnant women who were visiting the Department of Obstetrics and Gynaecology at RIPAS Hospital for routine antenatal care between February and March 2011 volunteered for this cross-sectional study. They did not present with any clinical symptoms of bacteriuria or indeed any other illness. They were investigated for bacteriuria by urine microscopy, culture, and sensitivity. Urine samples from seven of the women produced significant bacterial growth, showing a prevalence of 4.1%. The organisms isolated were Klebsiella species (2.94%) and Escherichia coli (1.18%); these bacteria were both sensitive to amoxicillin, vancomycin, tetracycline, and erythromycin. Brunei has a similar prevalence of asymptomatic bacteriuria to other South-East Asian countries.

A Preliminary Assessment of Asymptomatic Bacteriuria of Pregnancy in Brunei Darussalam

PubMed Central

MUHARRAM, Siti Hanna; GHAZALI, Siti Nur Bazilah; YAAKUB, Hajah Roselina; ABIOLA, Oduola

2014-01-01

Background: Asymptomatic bacteriuria describes a condition in which urine culture reveals a significant growth of pathogenic bacteria, specifically greater than 105 of colony-forming units per millilitre of urine. It has a direct bearing on the health of a pregnant woman, her pregnancy and consequently the foetus. Thus, this study investigated the prevalence of asymptomatic bacteriuria of pregnancy in Raja Isteri Pengiran Anak Saleha (RIPAS) Hospital, the premiere tertiary hospital in Brunei Darussalam. Methods: A total of 170 pregnant women who were visiting the Department of Obstetrics and Gynaecology at RIPAS Hospital for routine antenatal care between February and March 2011 volunteered for this cross-sectional study. They did not present with any clinical symptoms of bacteriuria or indeed any other illness. They were investigated for bacteriuria by urine microscopy, culture, and sensitivity. Results: Urine samples from seven of the women produced significant bacterial growth, showing a prevalence of 4.1%. The organisms isolated were Klebsiella species (2.94%) and Escherichia coli (1.18%); these bacteria were both sensitive to amoxicillin, vancomycin, tetracycline, and erythromycin. Conclusion: Brunei has a similar prevalence of asymptomatic bacteriuria to other South-East Asian countries. PMID:24876805

Accuracy of diagnostic tests to detect asymptomatic bacteriuria during pregnancy.

PubMed

Mignini, Luciano; Carroli, Guillermo; Abalos, Edgardo; Widmer, Mariana; Amigot, Susana; Nardin, Juan Manuel; Giordano, Daniel; Merialdi, Mario; Arciero, Graciela; Del Carmen Hourquescos, Maria

2009-02-01

A dipslide is a plastic paddle coated with agar that is attached to a plastic cap that screws onto a sterile plastic vial. Our objective was to estimate the diagnostic accuracy of the dipslide culture technique to detect asymptomatic bacteriuria during pregnancy and to evaluate the accuracy of nitrate and leucocyte esterase dipslides for screening. This was an ancillary study within a trial comparing single-day with 7-day therapy in treating asymptomatic bacteriuria. Clean-catch midstream samples were collected from pregnant women seeking routine care. Positive and negative likelihood ratios and sensitivity and specificity for the culture-based dipslide to detect and chemical dipsticks (nitrites, leukocyte esterase, or both) to screen were estimated using traditional urine culture as the "gold standard." : A total of 3,048 eligible pregnant women were screened. The prevalence of asymptomatic bacteriuria was 15%, with Escherichia coli the most prevalent organism. The likelihood ratio for detecting asymptomatic bacteriuria with a positive dipslide test was 225 (95% confidence interval [CI] 113-449), increasing the probability of asymptomatic bacteriuria to 98%; the likelihood ratio for a negative dipslide test was 0.02 (95% CI 0.01-0.05), reducing the probability of bacteriuria to less than 1%. The positive likelihood ratio of leukocyte esterase and nitrite dipsticks (when both or either one was positive) was 6.95 (95% CI 5.80-8.33), increasing the probability of bacteriuria to only 54%; the negative likelihood ratio was 0.50 (95% CI 0.45-0.57), reducing the probability to 8%. A pregnant woman with a positive dipslide test is very likely to have a definitive diagnosis of asymptomatic bacteriuria, whereas a negative result effectively rules out the presence of bacteriuria. Dipsticks that measure nitrites and leukocyte esterase have low sensitivity for use in screening for asymptomatic bacteriuria during gestation. ISRCTN, isrctn.org, 1196608 II.

Escherichia coli pathotypes

USDA-ARS?s Scientific Manuscript database

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...

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

PubMed

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.

Pasteurella aerogenes as an Asymptomatic Bacteriuria Agent.

PubMed

Alaygut, Demet; Engin, Aynur

2018-02-01

'Asymptomatic bacteriuria' (ASB) is isolation of a specified quantitative count of bacteria in an appropriately collected urine specimen obtained from a person without symptoms or signs referable to urinary infection. Catheterized specimens are less likely to be contaminated compared with voided specimens; therefore, positive cultures of catheterized specimens are more likely to reflect true bladder bacteriuria even with low colony counts. The common pathogens for ASB are Escherichia coli, Klebsiella and Streptococcus spp. Pasteurella spp. was not previously reported as an ASB agent. ASB is important for pregnant women, children, individuals with obstructive uropathy, chronic renal failure and neutropenia, before the urologic procedures and after renal transplantation. Treatment of ASB is required for above situations. We report an 11-year-old-girl with neurogenic bladder who made clean intermittent catheterization and had Pasteurella aerogenes as an ASB agent. © The Author [2017]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Asymptomatic bacteriuria of pregnancy in Ibadan, Nigeria: a re-assessment.

PubMed

Akinloye, O; Ogbolu, D O; Akinloye, O M; Terry Alli, O A

2006-01-01

Asymptomatic bacteriuria in pregnancy is the major risk factor for developing symptomatic urinary tract infection during pregnancy. In the present study, 300 pregnant women are screened for significant asymptomatic bacteriuria in order to provide an insight into the prevalence in developing countries, reassessment of some predisposing factors and aetiological agents and their susceptibility tests. The mean age of the patients in the study is 26.8 years (SD: 5.8 years, range: 16-40 years). Using 10(3) organisms/mL as a significant level of bacteriuria, the prevalence was found to be 21.0%. One hundred and fifty-eight samples had no pus cells, with 25 showing significant bacteriuria, 116 samples contained 1-4 pus cells/high power field (hpf) with 25 showing significant bacteriuria, while 26 samples had > or = 5 pus cells/hpf with 13 showing significant bacteriuria. There was no particular trend associated with age and rate of infection. However, there was a decline in the rate of infection in the 26-30 age group, with a sharp increase as age increased. There was high incidence of bacteriuria during the third trimester of pregnancy (21.9%) compared with that in the first trimester (7.7%), while the level in the second trimester was 22.5%. Multiparity is associated with increased bacteriuria in pregnancy. Thirty-one (49.2%) isolates grew Gram-negative bacilli; 27 (42.9%) grew Gram-positive cocci and the remainder (7.9%) grew yeast-like cells. Staphylococcus aureus was the most frequent pathogen (41.3%), followed by Klebsiella species (33.3%) and Escherichia coli (11.1%). Bacterial isolates from this study were most sensitive to ceftazidime, followed by ceftriazone, and least susceptible to co-trimoxazole.

Comparative analysis of antibiotic resistance and phylogenetic group patterns in human and porcine urinary tract infectious Escherichia coli.

PubMed

Hancock, Viktoria; Nielsen, Eva Møller; Krag, Louise; Engberg, Jørgen; Klemm, Per

2009-11-01

Urinary tract infections (UTIs) are one of the most common infectious diseases in humans and domestic animals such as pigs. The most frequent infectious agent in such infections is Escherichia coli. Virulence characteristics of E. coli UTI strains range from highly virulent pyelonephritis strains to relatively benign asymptomatic bacteriuria strains. Here we analyse a spectrum of porcine and human UTI E. coli strains with respect to their antibiotic resistance patterns and their phylogenetic groups, determined by multiplex PCR. The clonal profiles of the strains differed profoundly; whereas human strains predominantly belonged to clonal types B2 and D, these were not seen among the porcine strains, which all belonged to the E. coli clonal groups A and B1. Contrary to the human strains, the majority of the porcine strains were multidrug resistant. The distinct profiles of the porcine strains suggest selective pressure due to extensive antibiotic use.

Rare emergence of symptoms during long-term asymptomatic Escherichia coli 83972 carriage without an altered virulence factor repertoire.

PubMed

Köves, Béla; Salvador, Ellaine; Grönberg-Hernández, Jenny; Zdziarski, Jaroslaw; Wullt, Björn; Svanborg, Catharina; Dobrindt, Ulrich

2014-02-01

Asymptomatic bacteriuria established by intravesical inoculation of Escherichia coli 83972 is protective in patients with recurrent urinary tract infections. In this randomized, controlled crossover study a total of 3 symptomatic urinary tract infection episodes developed in 2 patients while they carried E. coli 83972. We examined whether virulence reacquisition by symptom isolates may account for the switch from asymptomatic bacteriuria to symptomatic urinary tract infection. We used E. coli 83972 re-isolates from 2 patients in a prospective study and from another 2 in whom symptoms developed after study completion. We phylogenetically classified the re-isolates, and identified the genomic restriction patterns and gene expression profiles as well as virulence gene structure and phenotypes. In vivo virulence was examined in the murine urinary tract infection model. The fim, pap, foc, hlyA, fyuA, iuc, iroN, kpsMT K5 and malX genotypes of the symptomatic re-isolates remained unchanged. Bacterial gene expression profiles of flagellated symptomatic re-isolates were unique to each host, providing no evidence of common deregulation. Symptomatic isolates did not differ in virulence from the wild-type strain, as defined in the murine urinary tract infection model by persistence, symptoms or innate immune activation. The switch from asymptomatic E. coli 83972 carriage to symptomatic urinary tract infection was not explained by reversion to a functional virulence gene repertoire. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Conjugation in Escherichia coli

PubMed Central

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

Recombinant Protein Expression in Escherichia coli (E.coli): What We Need to Know.

PubMed

Hayat, Seyed Mohammad Gheibi; Farahani, Najmeh; Golichenari, Behrouz; Sahebkar, Amir Hosein

2018-01-31

Host, vector, and culture conditions (including cultivation media) are considered among the three main elements contributing to a successful production of recombinant proteins. Accordingly, one of the most common hosts to produce recombinant therapeutic proteins is Escherichia coli. A comprehensive literature review was performed to identify important factors affecting production of recombinant proteins in Escherichia coli. Escherichia coli is taken into account as the easiest, quickest, and cheapest host with a fully known genome. Thus, numerous modifications have been carried out on Escherichia coli to optimize it as a good candidate for protein expression and; as a result, several engineered strains of Escherichia coli have been designed. In general; host strain, vector, and cultivation parameters are recognized as crucial ones determining success of recombinant protein expression in Escherichia coli. In this review, the role of host, vector, and culture conditions along with current pros and cons of different types of these factors leading to success of recombinant protein expression in Escherichia coli were discussed. Successful protein expression in Escherichia coli necessitates a broad knowledge about physicochemical properties of recombinant proteins, selection among common strains of Escherichia coli and vectors, as well as factors related to media including time, temperature, and inducer. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

PATHOGENIC ESCHERICHIA COLI

EPA Science Inventory

Escherichia coli is a bacterial species which inhabits the gastrointestinal tract of man and warm-blooded animals. Because of the ubiquity of this bacterium in the intestinal flora, it serves as an important indicator organism of fecal contamination. E. coli, aside from serving a...

Evaluation of the Live Biotherapeutic Product, Asymptomatic Bacteriuria Escherichia coli 2-12, in Healthy Dogs and Dogs with Clinical Recurrent UTI.

PubMed

Segev, G; Sykes, J E; Klumpp, D J; Schaeffer, A J; Antaki, E M; Byrne, B A; Yaggie, R E; Westropp, J L

2018-01-01

Antimicrobial resistance is an emerging problem. To investigate the safety and efficacy of a live biotherapeutic product, ASB E. coli 2-12 for UTI treatment. Six healthy research dogs; nine client-owned dogs with recurrent UTI. Prospective noncontrolled clinical trial. For safety data, research dogs were sedated, a urinary catheter was inserted into the bladder; 10 10 CFU/mL of ASB E. coli 2-12 was instilled. Urine was cultured on days 1, 3, and 8 post-instillation and dogs were observed for lower urinary tract signs (LUTS). For client-owned dogs, ASB E. coli 2-12 was instilled similarly and urine cultures analyzed on days 1, 7, and 14 days postinstillation. No LUTS were noted in any of the 6 research dogs after ASB E. coli 2-12 infusion. Pulse field gel electrophoresis (PFGE) studies confirmed the bacterial strains isolated matched that ASB E. coli 2-12 strain. Four of the nine client-owned dogs had complete or nearly complete clinical cures by day 14. Of these four dogs, 3 also had microbiologic cures at day 14; one of these dogs had subclinical bacteriuria (in addition to ASB E. coli 2-12). Three of these four dogs had ASB E. coli 2-12 isolated from their urine at day 14. With the exception of mild, temporary, self-limiting, hyporexia in two dogs on the day of biotherapeutic administration, there were no major adverse effects. These results suggest ASB E. coli 2-12 is safe and should be investigated in a larger controlled study evaluating clinical UTI in dogs. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Asymptomatic bacteriuria and concomitant presence of other micro-organisms in urine of pregnant women in Dar es Salaam -- Tanzania.

PubMed

Mtimavalye, L A; Runyoro, D E; Massawe, F N; Mhalu, F S; Kanyawana, J Z

1983-09-01

This study was designed to determine the prevalence of significant bacteriuria in pregnancy in Dar es Salaam as well as attempt to find out whether bacteriuria has any effects on the mother and baby. Of 1007 pregnant women studied for asymptomatic bacteriuria, a significant bacteriuria rate of 6.3% was revealed. Escherichia coli was the predominant organism, making up 47.6% of the total organisms isolated. Schistosoma hematobium was present in 8.7%, T. vaginalis in 14%, yeast cells were found in the urine of 9.1% and the microfilariae of Wuchereria bancrofti were found in 1 specimen. 66.2% had no abnormality in their urine. It is recommended on the basis of this study that all women found to have significant bacteriuria in 1 cultured urine sample should be treated. There was a significant relationship noted between significant bacteriuria and the passing of S. hematobium in the urine. There was also a significant correlation between the presence of T. vaginalis and yeast cells in the urine. On the basis of laboratory sensitivity studies it was also found that the antimicrobial agents of choice for treating urinary tract infections in Dar es Salaam where E. coli and Klebsiella erogenes are the predominant organisms are nitrofurantoin, nalidixic acid and co-trimoxazole. The socioeconomic status of the bacteriuric and control group was divided into 4 groups according to take home pay; results show no significant increase of bacteriuria in any of the groups. It was not possible to follow up the effects of the presence of micro-organisms in urine during pregnancy because once a woman was found to have a positive culture she was treated.

Pathogenic Escherichia coli

USDA-ARS?s Scientific Manuscript database

Escherichia coli, a member of the Enterobacteriaceae family, is a part of the normal flora of the intestinal tract of humans and a variety of animals. E. coli strains are classified on the basis of antigenic differences in two surface components (serotyping), the somatic antigen (O) of the lipopoly...

Virulence factors in Escherichia coli urinary tract infection.

PubMed Central

Johnson, J R

1991-01-01

Uropathogenic strains of Escherichia coli are characterized by the expression of distinctive bacterial properties, products, or structures referred to as virulence factors because they help the organism overcome host defenses and colonize or invade the urinary tract. Virulence factors of recognized importance in the pathogenesis of urinary tract infection (UTI) include adhesins (P fimbriae, certain other mannose-resistant adhesins, and type 1 fimbriae), the aerobactin system, hemolysin, K capsule, and resistance to serum killing. This review summarizes the virtual explosion of information regarding the epidemiology, biochemistry, mechanisms of action, and genetic basis of these urovirulence factors that has occurred in the past decade and identifies areas in need of further study. Virulence factor expression is more common among certain genetically related groups of E. coli which constitute virulent clones within the larger E. coli population. In general, the more virulence factors a strain expresses, the more severe an infection it is able to cause. Certain virulence factors specifically favor the development of pyelonephritis, others favor cystitis, and others favor asymptomatic bacteriuria. The currently defined virulence factors clearly contribute to the virulence of wild-type strains but are usually insufficient in themselves to transform an avirulent organism into a pathogen, demonstrating that other as-yet-undefined virulence properties await discovery. Virulence factor testing is a useful epidemiological and research tool but as yet has no defined clinical role. Immunological and biochemical anti-virulence factor interventions are effective in animal models of UTI and hold promise for the prevention of UTI in humans. Images PMID:1672263

Asymptomatic bacteriuria and antimicrobial susceptibility pattern of the isolates among pregnant women attending Dessie referral hospital, Northeast Ethiopia: A hospital-based cross-sectional study.

PubMed

Ali, Ismail Ebrie; Gebrecherkos, Teklay; Gizachew, Mucheye; Menberu, Martha Alemayehu

2018-05-01

The aim of the current study was to find out the prevalence of asymptomatic bacteriuria, antimicrobial susceptibility pattern of the isolates and related risk factors among pregnant women. A hospital-based cross-sectional study was carried out from February 2017 to May 2017 among asymptomatic pregnant mothers attending Dessie Referral Hospital, Northeast Ethiopia. About 10-15 mL of freshly voided midstream urine samples were collected from each study participants, and analyzed at Dessie regional research microbiology laboratory with conventional antibiotic susceptibility, and biochemical tests. Isolates were tested against commonly used antimicrobials using Kirby Bauer disc diffusion method. Data were analyzed by SPSS version 20 software and in all cases, p-values below 0.05 was considered as statistically significant. Overall, 358 pregnant women were included in the study with a mean age of 26.5±4.6 years (range, 19-43 yrs). The overall prevalence of asymptomatic bacteriuria was 56% (15.6%). Isolated microorganisms were mainly Escherichia coli and Staphylococcus aureus (for each, n=18; 31%). Escherichia coli and Staphylococcus aureus were resistant to ampicillin (66.7%), and penicillin (94.44%). The prevalence of multidrug- resistant isolates was 72.4%. History of catheterization [AOR=2.28, 95% CI=(1.03-5.06)] and anemia [AOR=4.98, 95% CI=(2.395-10.34) were statistically significant regarding the prevalence of asymptomatic bacteriuria. The overall prevalence of asymptomatic bacteriuria among pregnant women in the study area was high. The presence of asymptomatic bacteriuria and their antibiotic susceptibility test results should be taken into consideration during the management of pregnant women who are visiting antenatal care clinic.

Asymptomatic bacteriuria and antimicrobial susceptibility pattern of the isolates among pregnant women attending Dessie referral hospital, Northeast Ethiopia: A hospital-based cross-sectional study

PubMed Central

Ali, Ismail Ebrie; Gebrecherkos, Teklay; Gizachew, Mucheye

2018-01-01

Objective The aim of the current study was to find out the prevalence of asymptomatic bacteriuria, antimicrobial susceptibility pattern of the isolates and related risk factors among pregnant women. Material and methods A hospital-based cross-sectional study was carried out from February 2017 to May 2017 among asymptomatic pregnant mothers attending Dessie Referral Hospital, Northeast Ethiopia. About 10–15 mL of freshly voided midstream urine samples were collected from each study participants, and analyzed at Dessie regional research microbiology laboratory with conventional antibiotic susceptibility, and biochemical tests. Isolates were tested against commonly used antimicrobials using Kirby Bauer disc diffusion method. Data were analyzed by SPSS version 20 software and in all cases, p-values below 0.05 was considered as statistically significant. Results Overall, 358 pregnant women were included in the study with a mean age of 26.5±4.6 years (range, 19–43 yrs). The overall prevalence of asymptomatic bacteriuria was 56% (15.6%). Isolated microorganisms were mainly Escherichia coli and Staphylococcus aureus (for each, n=18; 31%). Escherichia coli and Staphylococcus aureus were resistant to ampicillin (66.7%), and penicillin (94.44%). The prevalence of multidrug- resistant isolates was 72.4%. History of catheterization [AOR=2.28, 95% CI=(1.03–5.06)] and anemia [AOR=4.98, 95% CI=(2.395–10.34) were statistically significant regarding the prevalence of asymptomatic bacteriuria. Conclusion The overall prevalence of asymptomatic bacteriuria among pregnant women in the study area was high. The presence of asymptomatic bacteriuria and their antibiotic susceptibility test results should be taken into consideration during the management of pregnant women who are visiting antenatal care clinic. PMID:29733799

Postoperative bacteriuria, pyuria and urinary tract infection in patients with an orthotopic sigmoid colon neobladder replacement.

PubMed

Shigemura, Katsumi; Tanaka, Kazushi; Arakawa, Soichi; Miyake, Hideaki; Fujisawa, Masato

2014-02-01

The purpose of this study is to investigate the prevalence of postoperative bacteriuria, pyuria and urine culture in patients with an orthotopic sigmoid colon neobladder replacement. Urine samples for bacteriuria, pyuria and urine culture, if necessary, were collected at 1, 3, 6, 9 and 12 months after surgery and the presence of blood culture and antibiotic-resistant strains, and their treatments on positive urine culture cases were investigated. Of 209 for bacteriuria and 207 for pyuria urine samples with evaluable data, 95 (45.5%) were positive for bacteriuria and 76 (36.7%) had pyuria (10 or more white blood cells per high-power field). Totally, 30 bacteria were isolated from urine culture of urinary tract infection (UTI) and Klebisiella pneumoniae, Escherichia coli, Staphylococcos aureus and Enterococcus spp. strains were representatively isolated. The incidence of pyuria significantly decreased over time (P=0.041) but that of bacteriuria did not (P=0.107). In them, there were six bacteria (20.7%) with antibiotic-resistant strains. The antibiotics used for their treatments representatively were levofloxacin in five cases, tazobactam/piperacillin in three cases and sulfamethoxazole/trimethoprim and cefepime, meropenem in two cases, respectively. In conclusion, these findings suggest that physicians taking care of sigmoid colon neobladder patients need to be aware of these high ratios of bacteriuria, pyuria and UTI, including bacteremia.

Enterobacteria secrete an inhibitor of Pseudomonas virulence during clinical bacteriuria

PubMed Central

Ohlemacher, Shannon I.; Giblin, Daryl E.; d’Avignon, D. André; Stapleton, Ann E.; Trautner, Barbara W.; Henderson, Jeffrey P.

2017-01-01

Escherichia coli and other Enterobacteriaceae are among the most common pathogens of the human urinary tract. Among the genetic gains of function associated with urinary E. coli isolates is the Yersinia high pathogenicity island (HPI), which directs the biosynthesis of yersiniabactin (Ybt), a virulence-associated metallophore. Using a metabolomics approach, we found that E. coli and other Enterobacteriaceae expressing the Yersinia HPI also secrete escherichelin, a second metallophore whose chemical structure matches a known synthetic inhibitor of the virulence-associated pyochelin siderophore system in Pseudomonas aeruginosa. We detected escherichelin during clinical E. coli urinary tract infection (UTI) and experimental human colonization with a commensal, potentially probiotic E. coli bacteriuria strain. Escherichelin production by colonizing enterobacteria may help human hosts resist opportunistic infections by Pseudomonas and other pyochelin-expressing bacteria. This siderophore-based mechanism of microbial antagonism may be one of many elements contributing to the protective effects of the human microbiome. Future UTI-preventive probiotic strains may benefit by retaining the escherichelin biosynthetic capacity of the Yersinia HPI while eliminating the Ybt biosynthetic capacity. PMID:28945201

Performance of a New Rapid Immunoassay Test Kit for Point-of-Care Diagnosis of Significant Bacteriuria

PubMed Central

Cox, Marsha E.; DiNello, Robert K.; Geisberg, Mark; Abbott, April; Roberts, Pacita L.; Hooton, Thomas M.

2015-01-01

Urinary tract infections (UTIs) are frequently encountered in clinical practice and most commonly caused by Escherichia coli and other Gram-negative uropathogens. We tested RapidBac, a rapid immunoassay for bacteriuria developed by Silver Lake Research Corporation (SLRC), compared with standard bacterial culture using 966 clean-catch urine specimens submitted to a clinical microbiology laboratory in an urban academic medical center. RapidBac was performed in accordance with instructions, providing a positive or negative result in 20 min. RapidBac identified as positive 245/285 (sensitivity 86%) samples with significant bacteriuria, defined as the presence of a Gram-negative uropathogen or Staphylococcus saprophyticus at ≥103 CFU/ml. The sensitivities for Gram-negative bacteriuria at ≥104 CFU/ml and ≥105 CFU/ml were 96% and 99%, respectively. The specificity of the test, detecting the absence of significant bacteriuria, was 94%. The sensitivity and specificity of RapidBac were similar on samples from inpatient and outpatient settings, from male and female patients, and across age groups from 18 to 89 years old, although specificity was higher in men (100%) compared with that in women (92%). The RapidBac test for bacteriuria may be effective as an aid in the point-of-care diagnosis of UTIs especially in emergency and primary care settings. PMID:26063858

Asymptomatic bacteriuria during pregnancy.

PubMed

Sheiner, Eyal; Mazor-Drey, Efrat; Levy, Amalia

2009-05-01

The present study was aimed to test the association between asymptomatic bacteriuria during pregnancy, among patients in whom antibiotic treatment was recommended, and perinatal outcome. Our study was also designed to characterize common bacteria and risk factors associated with asymptomatic bacteriuria during pregnancy. A retrospective population-based study comparing all singleton pregnancies of women with and asymptomatic bacteriuria was conducted. Patients with urinary tract infection were excluded from the analysis. Multiple logistic regression model was used to control for confounders. Out of 199,093 deliveries, 2.5% (n = 4890) were in patients with asymptomatic bacteriuria. E. coli was the most common pathogen associated with asymptomatic bacteriuria, representing 78.6% of the cultures with specified growth. Patients with asymptomatic bacteriuria were more likely to deliver preterm (PTD, 13.3%vs. 7.6%, odd ratio (OR) = 1.9, 95% confidence interval CI 1.7-2.0; P < 0.001) and deliver low birth-weight neonates (<2500 g, 13.3%vs. 7.9%, OR = 1.8; 95% CI 1.6-2.0; P < 0.001). Asymptomatic bacteriuria was independently associated with PTD (adjusted OR = 1.6; 95% CI 1.5-1.7; P < 0.001), fertility treatments, hypertensive disorders, recurrent abortions, diabetes mellitus, intrauterine growth restriction, polyhydramnion and oligohydramnion, premature rupture of membranes and labour induction, in a multivariable analysis with backwards elimination. Perinatal mortality rates (1.5%vs. 1.4%; P = 0.707) as well as low 5 min Apgar scores (0.8%vs. 0.6%; P = 0.065) were comparable between the groups. Asymptomatic bacteriuria is an independent risk factor for preterm delivery.

Prevalence of Asymptomatic Bacteriuria and its Antibacterial Susceptibility Pattern Among Pregnant Women Attending the Antenatal Clinic at Kanpur, India

PubMed Central

Nawani, Manju

2014-01-01

Background: Symptomatic and asymptomatic bacteriuria (ASB) is common in pregnant women. Pregnancy enhances the progression from ASB to symptomatic bacteriuria, which if left untreated, could lead to acute pyelonephritis and other adverse outcomes such as prematurity, postpartum, hypertensive disease, anaemia, UTIs and higher foetal mortality rates. Aim: To identify the prevalence of ASB, the most common causative microorganisms and the antibacterial susceptibilities of the isolated microorganisms at a tertiary care centre at Kanpur, India. Materials and Methods: A total number of 300 asymptomatic pregnant women were screened for ASB by urine culture by using a semi quantitative culture method. Results: In this study, significant bacteriuria was found in only 22 cases (7.3%). Growth of contaminants was seen in 40 cases (13.3%). Among cases which showed positive cultures, 48.9% were primigravidae and 51.1% were multigravidae. Highest incidence was reported in age group of 21-30 years. The predominant organisms which were isolated were Escherichia coli, followed by Klebsiella pneumoniae, Enterococcus faecalis, Staphylococcus aureus and Proteus mirabilis. Escherichia coli, the most common isolate, was found to be only 61% and 70% sensitive to ampicillin and amoxicillin + clavulanate, respectively. Sensitivity to ceftriaxone and ciprofloxacin was 95%, and sensitivity to amikacin was 99%. Hundred percent sensitivity was found for the broad spectrum pencillins, imipenem, and meropenem. Klebsiella pneumoniae, the second most frequent organism which was grown on culture, was only 11% sensitive to ampicillin, while sensitivity to amoxicillin + clavulanate and cefuroxime was 86%. 100% sensitivity was found for cefepime, ceftriaxone, ciprofloxacin, imipenem and meropenem. Conclusion: Routine urine culture test should be carried out for all antenatal women, to detect asymptomatic bacteriuria, and every positive case should be treated with appropriate antibiotic therapy, to

Prevalence of asymptomatic bacteriuria and its antibacterial susceptibility pattern among pregnant women attending the antenatal clinic at kanpur, India.

PubMed

Sujatha, R; Nawani, Manju

2014-04-01

Symptomatic and asymptomatic bacteriuria (ASB) is common in pregnant women. Pregnancy enhances the progression from ASB to symptomatic bacteriuria, which if left untreated, could lead to acute pyelonephritis and other adverse outcomes such as prematurity, postpartum, hypertensive disease, anaemia, UTIs and higher foetal mortality rates. To identify the prevalence of ASB, the most common causative microorganisms and the antibacterial susceptibilities of the isolated microorganisms at a tertiary care centre at Kanpur, India. A total number of 300 asymptomatic pregnant women were screened for ASB by urine culture by using a semi quantitative culture method. In this study, significant bacteriuria was found in only 22 cases (7.3%). Growth of contaminants was seen in 40 cases (13.3%). Among cases which showed positive cultures, 48.9% were primigravidae and 51.1% were multigravidae. Highest incidence was reported in age group of 21-30 years. The predominant organisms which were isolated were Escherichia coli, followed by Klebsiella pneumoniae, Enterococcus faecalis, Staphylococcus aureus and Proteus mirabilis. Escherichia coli, the most common isolate, was found to be only 61% and 70% sensitive to ampicillin and amoxicillin + clavulanate, respectively. Sensitivity to ceftriaxone and ciprofloxacin was 95%, and sensitivity to amikacin was 99%. Hundred percent sensitivity was found for the broad spectrum pencillins, imipenem, and meropenem. Klebsiella pneumoniae, the second most frequent organism which was grown on culture, was only 11% sensitive to ampicillin, while sensitivity to amoxicillin + clavulanate and cefuroxime was 86%. 100% sensitivity was found for cefepime, ceftriaxone, ciprofloxacin, imipenem and meropenem. Routine urine culture test should be carried out for all antenatal women, to detect asymptomatic bacteriuria, and every positive case should be treated with appropriate antibiotic therapy, to prevent any obstetric complication which is associated with

Asymptomatic bacteriuria in pregnancy: epidemiological, clinical and microbiological approach.

PubMed

Gebre-Selassie, S

1998-07-01

Asymptomatic urinary tract infection is a risk factor for fetal and maternal morbidity including development of pyelonephritis, premature labor and impaired intra-uterine development. In this study, 326 pregnant and 100 non-pregnant control women were screened for significant asymptomatic bacteriuria from April 8 to July 25, 1997 to gain insight into the prevalence rate, clinical characteristics of the disease and microbiological assessments of the causative agents. All the subjects were clinically identified to have no signs and symptoms of urinary tract infection (UTI). The age ranges of the study and control groups were between 15-40 years for both groups with mean of 25.1 and 25.3 years, respectively. Bacteriological screening of mid-stream urine (MSU) revealed that 24/326 (7%) and 3/100 (3%) were positive for asymptomatic bacteriuria in the study group and controls, respectively (P < 0.05). Further biochemical species identification showed that Escherichia coli was found in 11/24 (46%) followed by coagulase-negative staphylococci (CNS) in 8/24 (33%) and Citrobacter freundii in 2/24 (8%). Others found in smaller number included Staphylococcus aureus, Enterobacter cloacae and Proteus rettgeri in 1/24 (4%) each. Antimicrobial susceptibility test revealed that 10/11 (91%) of the E. coli isolates were resistant to ampicillin and amoxicillin and 10/11 (91%) of them sensitive to nitrofurantoin.

Repeated Treatments with Chitosan in Combination with Antibiotics Completely Eradicate Uropathogenic Escherichia coli From Infected Mouse Urinary Bladders.

PubMed

Erman, Andreja; Hergouth, Veronika Križan; Blango, Matthew G; Kos, Mojca Kerec; Mulvey, Matthew A; Veranic, Peter

2017-08-01

Uropathogenic Escherichia coli (UPEC), the primary causative agents of urinary tract infections, colonize and invade the epithelial cells of the bladder urothelium. Infection of immature urothelial cells can result in the formation of persistent intracellular reservoirs that are refractory to antibiotic treatments. Previously, we defined a novel therapeutic strategy that used the bladder cell exfoliant chitosan to deplete UPEC reservoirs. However, although a single treatment of chitosan followed by ciprofloxacin administration had a marked effect on reducing UPEC titers within the bladder, this treatment failed to prevent relapsing bacteriuria. We show here that repeated use of chitosan in conjunction with the antibiotic ciprofloxacin completely eradicates UPEC from the urinary tract and prevents the development of relapsing bouts of bacteriuria. In addition, microscopy revealed rapid restoration of bladder integrity following chitosan treatment, indicating that chitosan can be used to effectively combat recalcitrant bladder infections without causing lasting harm to the urothelium. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Diarrheagenic Escherichia coli

PubMed Central

Nataro, James P.; Kaper, James B.

1998-01-01

Escherichia coli is the predominant nonpathogenic facultative flora of the human intestine. Some E. coli strains, however, have developed the ability to cause disease of the gastrointestinal, urinary, or central nervous system in even the most robust human hosts. Diarrheagenic strains of E. coli can be divided into at least six different categories with corresponding distinct pathogenic schemes. Taken together, these organisms probably represent the most common cause of pediatric diarrhea worldwide. Several distinct clinical syndromes accompany infection with diarrheagenic E. coli categories, including traveler’s diarrhea (enterotoxigenic E. coli), hemorrhagic colitis and hemolytic-uremic syndrome (enterohemorrhagic E. coli), persistent diarrhea (enteroaggregative E. coli), and watery diarrhea of infants (enteropathogenic E. coli). This review discusses the current level of understanding of the pathogenesis of the diarrheagenic E. coli strains and describes how their pathogenic schemes underlie the clinical manifestations, diagnostic approach, and epidemiologic investigation of these important pathogens. PMID:9457432

Prevention of renal scarring from pyelonephritis in nonhuman primates by vaccination with a synthetic Escherichia coli serotype O8 oligosaccharide-protein conjugate.

PubMed Central

Roberts, J A; Kaack, M B; Baskin, G; Svenson, S B

1993-01-01

Rhesus monkeys were vaccinated with a synthetic Escherichia coli serotype O8 oligosaccharide-protein conjugate. Using our experimental pyelonephritis monkey model, we tested whether such immunization was protective against the renal damage from inflammation following experimental infection with a P-fimbriated O-antigenically homologous E. coli strain. The vaccination did not significantly alter the duration of bacteriuria or interfere with the infection. However, the vaccine was efficient in renal protection, as vaccinated animals showed significantly less intratubular infiltration of neutrophils (P < 0.02) and the degree of renal scarring was also significantly less in these animals (P > 0.005) than in the control animals. Total kidney involvement in the vaccinated animals was 16.9%, compared with 32.5% in the control animals (P = 0.07). PMID:8225595

Bacteriuria amongst Pregnant Women in the Buea Health District, Cameroon: Prevalence, Predictors, Antibiotic Susceptibility Patterns and Diagnosis

PubMed Central

Mokube, Morike Ngoe; Atashili, Julius; Halle-Ekane, Gregory Edie; Ikomey, George M.; Ndumbe, Peter M.

2013-01-01

Background Bacteriuria is associated with significant maternal and foetal risks. However, its prevalence is not known in our community. Objectives This study was carried out to determine the prevalence and predictors of bacteriuria in pregnant women of the Buea Health District (BHD) as well as the antibiotic sensitivity patterns of bacterial isolates. It also sought to determine the diagnostic performance of the nitrite and leucocyte esterase tests in detecting bacteriuria in these women. Methods An observational analytic cross-sectional study was carried out amongst pregnant women attending selected antenatal care centres in Buea. We recruited 102 consenting pregnant women for the study. Demographic and clinical data were collected using structured questionnaires. Clean catch midstream urine was collected from each participant in sterile leak proof containers. Samples were examined biochemically, microscopically and by culture. Significant bacteriuria was defined as the presence of ≥108 bacteria/L of cultured urine. Identification and susceptibility of isolates was performed using API 20E and ATB UR EU (08) (BioMerieux, Marcy l'Etoile, France). Results Significant bacteriuria was found in the urine of 24 of the 102 women tested giving a bacteriuria prevalence of 23.5% in pregnant women of the BHD. Asymptomatic bacteriuria was detected in 8(7.8%) of the women. There was no statistically significant predictor of bacteriuria. Escherichia coli were the most isolated (33%) uropathogens and were 100% sensitive to cefixime, cefoxitin and cephalothin. The nitrite and leucocyte esterase tests for determining bacteriuria had sensitivities of 8%, 20.8% and specificities of 98.7% and 80.8% respectively. Conclusion Bacteriuria is frequent in pregnant women in the BHD suggesting the need for routine screening by urine culture. Empiric treatment with cefixime should be instituted until results of urine culture and sensitivity are available. Nitrite and leucocyte esterase tests

Bacteriuria amongst pregnant women in the Buea Health District, Cameroon: prevalence, predictors, antibiotic susceptibility patterns and diagnosis.

PubMed

Mokube, Morike Ngoe; Atashili, Julius; Halle-Ekane, Gregory Edie; Ikomey, George M; Ndumbe, Peter M

2013-01-01

Bacteriuria is associated with significant maternal and foetal risks. However, its prevalence is not known in our community. This study was carried out to determine the prevalence and predictors of bacteriuria in pregnant women of the Buea Health District (BHD) as well as the antibiotic sensitivity patterns of bacterial isolates. It also sought to determine the diagnostic performance of the nitrite and leucocyte esterase tests in detecting bacteriuria in these women. An observational analytic cross-sectional study was carried out amongst pregnant women attending selected antenatal care centres in Buea. We recruited 102 consenting pregnant women for the study. Demographic and clinical data were collected using structured questionnaires. Clean catch midstream urine was collected from each participant in sterile leak proof containers. Samples were examined biochemically, microscopically and by culture. Significant bacteriuria was defined as the presence of ≥10⁸ bacteria/L of cultured urine. Identification and susceptibility of isolates was performed using API 20E and ATB UR EU (08) (BioMerieux, Marcy l'Etoile, France). Significant bacteriuria was found in the urine of 24 of the 102 women tested giving a bacteriuria prevalence of 23.5% in pregnant women of the BHD. Asymptomatic bacteriuria was detected in 8(7.8%) of the women. There was no statistically significant predictor of bacteriuria. Escherichia coli were the most isolated (33%) uropathogens and were 100% sensitive to cefixime, cefoxitin and cephalothin. The nitrite and leucocyte esterase tests for determining bacteriuria had sensitivities of 8%, 20.8% and specificities of 98.7% and 80.8% respectively. Bacteriuria is frequent in pregnant women in the BHD suggesting the need for routine screening by urine culture. Empiric treatment with cefixime should be instituted until results of urine culture and sensitivity are available. Nitrite and leucocyte esterase tests were not sensitive enough to replace urine

Escherichia Coli

ERIC Educational Resources Information Center

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…

Prevalence of antimicrobial resistant Escherichia coli from patients with suspected urinary tract infection in primary care, Denmark.

PubMed

Córdoba, Gloria; Holm, Anne; Hansen, Frank; Hammerum, Anette M; Bjerrum, Lars

2017-10-10

Escherichia coli is the most common pathogen causing Urinary Tract Infections (UTI). Data from the current National Surveillance program in Denmark (DANMAP) may not accurately represent the prevalence of resistant E. coli in primary care, because only urine samples from complicated cases may be forwarded to the microbiological departments at hospitals for diagnostic examination. The aim of this study was to assess the prevalence of resistant E. coli to the most commonly used antimicrobial agents in primary care in a consecutive sample of patients from general practice. Observational study carried out from December 2014 to December 2015. Thirty-nine general practices from The Capital Region of Denmark included adult patients with urinary tract symptoms and suspected UTI. All urine samples were sent to the central laboratory Statens Serum Institut (SSI). Significant bacteriuria was interpreted according to the European Urinalysis Standards. Susceptibility testing was performed and interpreted according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) standards. From the 39 general practices 505 patients were recruited. Completed data were obtained from 485 (96%) patients. According to the European Urinalysis Standards, 261 (54%) patients had positive bacteriuria. The most common uropathogen in patients with uncomplicated (uUTI) and complicated (cUTI) urinary tract infection was E. coli 105 (69%) and 76 (70%), respectively. Eighty-two (45%) of 181 E. coli isolates were resistant to at least one of the tested antibiotics and 50 out of 82 isolates were resistant to two or more antimicrobial agents. The highest resistance-rate was found against ampicillin 34% (95% CI 24;42) in uUTI and 36% (24;46) in cUTI. There were no differences in the distribution of resistance between uncomplicated and complicated cases. The prevalence of resistance was similar to the one reported in DANMAP 2014. In E. coli from uUTI there is high resistance rates to

Deliberate Establishment of Asymptomatic Bacteriuria-A Novel Strategy to Prevent Recurrent UTI.

PubMed

Wullt, Björn; Svanborg, Catharina

2016-07-29

We have established a novel strategy to reduce the risk for recurrent urinary tract infection (UTI), where rapidly increasing antibiotic resistance poses a major threat. Epidemiologic studies have demonstrated that asymptomatic bacteriuria (ABU) protects the host against symptomatic infections with more virulent strains. To mimic this protective effect, we deliberately establish ABU in UTI-prone patients, who are refractory to conventional therapy. The patients are inoculated with Escherichia coli (E. coli) 83972, now widely used as a prototype ABU strain. Therapeutic efficacy has been demonstrated in a placebo-controlled trial, supporting the feasibility of using E. coli 83972 as a tool to prevent recurrent UTI and, potentially, to outcompete antibiotic-resistant strains from the human urinary tract. In addition, the human inoculation protocol offers unique opportunities to study host-parasite interaction in vivo in the human urinary tract. Here, we review the clinical evidence for protection using this approach as well as some molecular insights into the pathogenesis of UTI that have been gained during these studies.

Rapid Growth of Uropathogenic Escherichia coli during Human Urinary Tract Infection.

PubMed

Forsyth, Valerie S; Armbruster, Chelsie E; Smith, Sara N; Pirani, Ali; Springman, A Cody; Walters, Matthew S; Nielubowicz, Greta R; Himpsl, Stephanie D; Snitkin, Evan S; Mobley, Harry L T

2018-03-06

Uropathogenic Escherichia coli (UPEC) strains cause most uncomplicated urinary tract infections (UTIs). These strains are a subgroup of extraintestinal pathogenic E. coli (ExPEC) strains that infect extraintestinal sites, including urinary tract, meninges, bloodstream, lungs, and surgical sites. Here, we hypothesize that UPEC isolates adapt to and grow more rapidly within the urinary tract than other E. coli isolates and survive in that niche. To date, there has not been a reliable method available to measure their growth rate in vivo Here we used two methods: segregation of nonreplicating plasmid pGTR902, and peak-to-trough ratio (PTR), a sequencing-based method that enumerates bacterial chromosomal replication forks present during cell division. In the murine model of UTI, UPEC strain growth was robust in vivo , matching or exceeding in vitro growth rates and only slowing after reaching high CFU counts at 24 and 30 h postinoculation (hpi). In contrast, asymptomatic bacteriuria (ABU) strains tended to maintain high growth rates in vivo at 6, 24, and 30 hpi, and population densities did not increase, suggesting that host responses or elimination limited population growth. Fecal strains displayed moderate growth rates at 6 hpi but did not survive to later times. By PTR, E. coli in urine of human patients with UTIs displayed extraordinarily rapid growth during active infection, with a mean doubling time of 22.4 min. Thus, in addition to traditional virulence determinants, including adhesins, toxins, iron acquisition, and motility, very high growth rates in vivo and resistance to the innate immune response appear to be critical phenotypes of UPEC strains. IMPORTANCE Uropathogenic Escherichia coli (UPEC) strains cause most urinary tract infections in otherwise healthy women. While we understand numerous virulence factors are utilized by E. coli to colonize and persist within the urinary tract, these properties are inconsequential unless bacteria can divide

Characterization of subclinical bacteriuria, bacterial cystitis, and pyelonephritis in dogs with chronic kidney disease.

PubMed

Foster, Jonathan D; Krishnan, Harathi; Cole, Stephen

2018-05-15

OBJECTIVE To determine the prevalence of bacteriuria (ie, a positive microbial culture result for ≥ 1 urine sample) in dogs with chronic kidney disease (CKD) and characterize findings of subclinical bacteriuria (SBU), bacterial cystitis, or pyelonephritis in these patients. DESIGN Retrospective, observational study. ANIMALS 182 dogs. PROCEDURES Medical records from January 2010 through July 2015 were reviewed to identify dogs with CKD that underwent urinalysis and urine microbial culture. Signalment, clinicopathologic data, stage of CKD according to previously published guidelines, results of urinalysis and urine culture, and abdominal ultrasonographic findings were recorded. Dogs with positive urine culture results were categorized as having SBU, bacterial cystitis, or pyelonephritis on the basis of these data. Prevalence of bacteriuria was calculated. Associations between CKD stage, presence of bacteriuria, and diagnosis category were analyzed statistically. RESULTS 33 of 182 (18.1%) dogs (40/235 [17.0%] urine samples) had positive culture results. All dogs received antimicrobials on the basis of culture and susceptibility test findings. Most positive culture results (18/40 [45%] samples) were found for dogs with SBU, followed by dogs with pyelonephritis (16/40 [40%]) and cystitis (6/40 [15%]). Escherichia coli was the most frequently observed isolate (29/40 [73%] cultures from 25/33 dogs). The CKD stage was not associated with presence of bacteriuria or diagnosis category. CONCLUSIONS AND CLINICAL RELEVANCE The prevalence of positive urine culture results in dogs with CKD was lower than that reported for dogs with some systemic diseases that may predispose to infection. Prospective research is needed to assess the clinical importance of SBU in dogs with CKD.

Pathogenic Escherichia coli and food handlers in luxury hotels in Nairobi, Kenya.

PubMed

Onyango, Abel O; Kenya, Eucharia U; Mbithi, John J N; Ng'ayo, Musa O

2009-11-01

The epidemiology and virulence properties of pathogenic Escherichia coli among food handlers in tourist destination hotels in Kenya are largely uncharacterized. This cross-sectional study among consenting 885 food handlers working in nine luxurious tourist hotels in Nairobi, Kenya determined the epidemiology, virulence properties, antibiotics susceptibility profiles and conjugation abilities of pathogenic Escherichia coli. Pathogenic Escherichia coli was detected among 39 (4.4%) subjects, including 1.8% enteroaggregative Escherichia coli (EAEC) harboring aggR genes, 1.2% enterotoxigenic Escherichia coli (ETEC) expressing both LT and STp toxins, 1.1% enteropathogenic Escherichia coli (EPEC) and 0.2% Shiga-like Escherichia coli (EHEC) both harboring eaeA and stx2 genes respectively. All the pathotypes had increased surface hydrophobicity. Using multivariate analyses, food handlers with loose stools were more likely to be infected with pathogenic Escherichia coli. Majority 53.8% of the pathotypes were resistant to tetracycline with 40.2% being multi-drug resistant. About 85.7% pathotypes trans-conjugated with Escherichia coli K12 F(-) NA(r) LA. The carriage of multi-drug resistant, toxin expressing pathogenic Escherichia coli by this population is of public health concern because exposure to low doses can result in infection. Screening food handlers and implementing public awareness programs is recommended as an intervention to control transmission of enteric pathogens.

Diarrheagenic Escherichia coli.

PubMed

Gomes, Tânia A T; Elias, Waldir P; Scaletsky, Isabel C A; Guth, Beatriz E C; Rodrigues, Juliana F; Piazza, Roxane M F; Ferreira, Luís C S; Martinez, Marina B

2016-12-01

Most Escherichia coli strains live harmlessly in the intestines and rarely cause disease in healthy individuals. Nonetheless, a number of pathogenic strains can cause diarrhea or extraintestinal diseases both in healthy and immunocompromised individuals. Diarrheal illnesses are a severe public health problem and a major cause of morbidity and mortality in infants and young children, especially in developing countries. E. coli strains that cause diarrhea have evolved by acquiring, through horizontal gene transfer, a particular set of characteristics that have successfully persisted in the host. According to the group of virulence determinants acquired, specific combinations were formed determining the currently known E. coli pathotypes, which are collectively known as diarrheagenic E. coli. In this review, we have gathered information on current definitions, serotypes, lineages, virulence mechanisms, epidemiology, and diagnosis of the major diarrheagenic E. coli pathotypes. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Detection of Bacteriuria by Canine Olfaction

PubMed Central

Maurer, Maureen; McCulloch, Michael; Willey, Angel M.; Hirsch, Wendi; Dewey, Danielle

2016-01-01

Background. Urinary tract infections (UTIs) are a significant medical problem , particularly for patients with neurological conditions and the elderly. Detection is often difficult in these patients, resulting in delayed diagnoses and more serious infections such as pyelonephritis and life-threatening sepsis. Many patients have a higher risk of UTIs because of impaired bladder function, catheterization, and lack of symptoms. Urinary tract infections are the most common nosocomial infection; however, better strategies are needed to improve early detection of the disease. Methods. In this double-blinded, case-control, validation study, we obtained fresh urine samples daily in a consecutive case series over a period of 16 weeks. Dogs were trained to distinguish urine samples that were culture-positive for bacteriuria from those of culture-negative controls, using reward-based clicker and treat methods. Results. Samples were obtained from 687 individuals (from 3 months to 92 years of age; 86% female and 14% male; 34% culture-positive and 66% culture-negative controls). Dogs detected urine samples positive for 100 000 colony-forming units/mL Escherichia coli (N = 250 trials; sensitivity 99.6%, specificity 91.5%). Dilution of E coli urine with distilled water did not affect accuracy at 1% (sensitivity 100%, specificity 91.1%) or 0.1% (sensitivity 100%, specificity 93.6%) concentration. Diagnostic accuracy was similar to Enterococcus (n = 50; sensitivity 100%, specificity 93.9%), Klebsiella (n = 50; sensitivity 100%, specificity 95.1%), and Staphylococcus aureus (n = 50; sensitivity 100%, specificity 96.3%). All dogs performed with similarly high accuracy: overall sensitivity was at or near 100%, and specificity was above 90%. Conclusions. Canine scent detection is an accurate and feasible method for detection of bacteriuria. PMID:27186578

Asymptomatic bacteriuria among an obstetric population in Ibadan.

PubMed

Awonuga, D O; Dada-Adegbola, H O; Fawole, A O; Olala, F A; Onimisi-Smith, H O

2011-01-01

Asymptomatic bacteriuria in pregnancy is the major risk factor for symptomatic urinary tract infection during pregnancy. Screening and identification of bacteriuria during pregnancy have been recommended. To determine the prevalence and pattern of asymptomatic bacteriuria associated with pregnancy. The study was a descriptive, cross sectional survey of pattern of asymptomatic bacteriuria among consecutive patients presenting for the first antenatal visit at a University College Hospital, during a period of two months. Relevant information obtained from all the patients recruited for the study included age, parity, educational level, gestational age and occupation of participant. Haemoglobin electrophoresis patterns were also retrieved and recorded. Main outcome measures were prevalence of asymptomatic bacteriuria, bacterial isolates and their antibiotic sensitivities. There were 205 eligible participants with a mean age of 30.6 ± 4.3 years and a mean gestational age at booking of 20.9 ±7.0 weeks. The prevalence of asymptomatic bacteriuria was 22(10.7%). The isolated pathogens were predominantly coliforms (Klebsiella and E. coli) accounting for 45.5% and Staphylococcus saprophyticus (27.3%). Only gentamycin, nitrofurantoin and ofloxacin demonstrated high efficacy against these uropathogens with antibiotic sensitivity rates of 72.7%-81.8%. Prevalence of asymptomatic bacteriuria in this centre is relatively high. This underscores the need for routine screening of pregnant women for bacteriuria.

The prevalence and bacteriology of asymptomatic bacteriuria among antenatal patients in Nnamdi Azikiwe University Teaching Hospital Nnewi; South Eastern Nigeria.

PubMed

Oli, A N; Okafor, C I; Ibezim, E C; Akujiobi, C N; Onwunzo, M C

2010-12-01

Urinary tract infection in pregnancy leads to poor pregnancy outcome. Diagnosis and treatment of asymptomatic bacteriuria markedly improves pregnancy outcome as well as reduce the incidence of acute pyelonephritis. To determine the prevalence and bacteriology of asymptomatic bacteriuria among Antenatal patients in our centre, and to know if routine screening will be justifiable. This was a prospective study carried out between April and August 2008. Sample size was statistically determined. Women who consented were interviewed and mid stream urine samples were collected and processed in the microbiology laboratory, using standard microbiological methods. Out of 357 women studied, 65(18.21%) had significant bacteriuria. Escherichia coli was the commonest isolate (25.6%), while proteus mirabilis was the least frequent isolate (3.66%). Women in third trimester had the highest prevalence (25.68%) while those in the first trimester had the least (15.79%). Women that had only primary education had the highest prevalence (27.50%) while those that had tertiary education had the least prevalence (21.10%). The prevalence of significant asymptomatic bacteriuria among the women studied was high. Screening of all the pregnant women and treatment will reduce the incidence and complications of overt urinary tract infection in pregnancy among these women.

76 FR 20542 - Escherichia coli

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-13

... Escherichia coli O157:H7, sequence negative for shiga toxins I and II, and grown on atoxigenic host bacteria... host bacteria. The temporary tolerance exemption expires on April 1, 2013. [[Page 20543

Asymptomatic bacteriuria.

PubMed

Nicolle, Lindsay E

2014-02-01

Asymptomatic bacteriuria is a common finding. Inappropriate antimicrobial treatment of asymptomatic bacteriuria has been identified as a major issue for antimicrobial stewardship programs. This review summarizes and evaluates recent studies which extend our knowledge of the occurrence, management, and outcomes of bacteriuria. The reported prevalence of bacteriuria is higher in some developing countries than generally reported for developed countries, but reasons for this remain unclear. Clinical studies of young women, renal transplant patients, and patients undergoing minor nontraumatic urologic procedures confirm that treatment of asymptomatic bacteriuria for these populations is not beneficial, and may be harmful. There is also no benefit for treatment of asymptomatic bacteriuria prior to orthopedic surgery to decrease postoperative surgical site infection. Studies continue to report substantial inappropriate antimicrobial use for treatment of asymptomatic bacteriuria. Recent publications confirm that asymptomatic bacteriuria is benign in most patients. Management strategies for pregnant women with recurrent bacteriuria require further clarification. There is a continuing problem with inappropriate treatment of asymptomatic bacteriuria, and sustainable strategies to optimize antimicrobial use for this problem are needed.

[Virulence markers of Escherichia coli O1 strains].

PubMed

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.

WGS accurately predicts antimicrobial resistance in Escherichia coli

USDA-ARS?s Scientific Manuscript database

Objectives: To determine the effectiveness of whole-genome sequencing (WGS) in identifying resistance genotypes of multidrug-resistant Escherichia coli (E. coli) and whether these correlate with observed phenotypes. Methods: Seventy-six E. coli strains were isolated from farm cattle and measured f...

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

EPA Science Inventory

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

EPA Science Inventory

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...

Recurrent urinary tract infection and urinary Escherichia coli in women ingesting cranberry juice daily: a randomized controlled trial.

PubMed

Stapleton, Ann E; Dziura, James; Hooton, Thomas M; Cox, Marsha E; Yarova-Yarovaya, Yuliya; Chen, Shu; Gupta, Kalpana

2012-02-01

To compare the time to urinary tract infection (UTI) and the rates of asymptomatic bacteriuria and urinary P-fimbriated Escherichia coli during a 6-month period in women ingesting cranberry vs placebo juice daily. Premenopausal women with a history of recent UTI were enrolled from November 16, 2005, through December 31, 2008, at 2 centers and randomized to 1 of 3 arms: 4 oz of cranberry juice daily, 8 oz of cranberry juice daily, or placebo juice. Time to UTI (symptoms plus pyuria) was the main outcome. Asymptomatic bacteriuria, adherence, and adverse effects were assessed at monthly visits. A total of 176 participants were randomized (120 to cranberry juice and 56 to placebo) and followed up for a median of 168 days. The cumulative rate of UTI was 0.29 in the cranberry juice group and 0.37 in the placebo group (P=.82). The adjusted hazard ratio for UTI in the cranberry juice group vs the placebo group was 0.68 (95% confidence interval, 0.33-1.39; P=.29). The proportion of women with P-fimbriated urinary E coli isolates during the intervention phase was 10 of 23 (43.5%) in the cranberry juice group and 8 of 10 (80.0%) in the placebo group (P=.07). The mean dose adherence was 91.8% and 90.3% in the cranberry juice group vs the placebo group. Minor adverse effects were reported by 24.2% of those in the cranberry juice group and 12.5% in the placebo group (P=.07). Cranberry juice did not significantly reduce UTI risk compared with placebo. The potential protective effect we observed is consistent with previous studies and warrants confirmation in larger, well-powered studies of women with recurrent UTI. The concurrent reduction in urinary P-fimbriated E coli strains supports the biological plausibility of cranberry activity. clinicaltrials.gov Identifier: NCT00128128. Copyright © 2012 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

76 FR 72331 - Shiga Toxin-Producing Escherichia coli in Certain Raw Beef Products

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-23

... Escherichia coli in Certain Raw Beef Products AGENCY: Food Safety and Inspection Service, USDA. ACTION: Public...-O157 Shiga toxin-producing Escherichia coli in raw, intact and non-intact beef products and product... implementation plans and methods for controlling non-O157 Shiga toxin-producing Escherichia coli in raw, intact...

Secretome Biomarkers for the Identification and Differentiation of Enterohemorrhagic and Enteropathogenic Escherichia coli Strains

DTIC Science & Technology

2013-09-01

SbBS512_E4084 Shigella byodii /EC NC101 ND ND ND EC: E. coli ND: not determined 8 Table 2. Common Strain-Unique Proteins from Replicate...E24377A- Escherichia coli str. K-12 substr. MG1655- Escherichia coli SE11- Escherichia coli- W3110 Shigella boy dii CDC 3083-94- Shigella boy dii Sb227

Human Meningitis-Associated Escherichia coli.

PubMed

Kim, Kwang Sik

2016-05-01

Escherichia coli is the most common Gram-negative bacillary organism causing meningitis, and E. coli meningitis continues to be an important cause of mortality and morbidity throughout the world. Our incomplete knowledge of its pathogenesis contributes to such mortality and morbidity. Recent reports of E. coli strains producing CTX-M-type or TEM-type extended-spectrum β-lactamases create a challenge. Studies using in vitro and in vivo models of the blood-brain barrier have shown that E. coli meningitis follows a high degree of bacteremia and invasion of the blood-brain barrier. E. coli invasion of the blood-brain barrier, the essential step in the development of E. coli meningitis, requires specific microbial and host factors as well as microbe- and host-specific signaling molecules. Blockade of such microbial and host factors contributing to E. coli invasion of the blood-brain barrier is shown to be efficient in preventing E. coli penetration into the brain. The basis for requiring a high degree of bacteremia for E. coli penetration of the blood-brain barrier, however, remains unclear. Continued investigation on the microbial and host factors contributing to a high degree of bacteremia and E. coli invasion of the blood-brain barrier is likely to identify new targets for prevention and therapy of E. coli meningitis.

Strategies for Protein Overproduction in Escherichia coli.

ERIC Educational Resources Information Center

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…

Laboratory aspects of asymptomatic bacteriuria in pregnancy.

PubMed

Mohammad, Marlyn; Mahdy, Zaleha A; Omar, Jamil; Maan, Noorashikin; Jamil, M A

2002-09-01

A total of 1,661 pregnant women aged between 13 and 45 years were screened for bacteriuria by urine culture. Of the 1,661 culture results, 615 (37%) yielded no growth; 728 (43.8%) yielded no significant growth (presence of <10(5) organisms/ml urine of one or more types of bacteria); 286 (17.2%) yielded mixed growth (presence of >10(5) organisms/ml urine of more than one type of bacteria) and only 32 (1.9%) showed significant growth (presence of >10(5) organisms/ml urine of a single bacterium). Urine microscopy was also conducted. Two hundred and twenty-four (13.5%) specimens had >10 white blood cells/ml urine, of which 66 had >100 white blood cells; 13 were from the significant growth group. Three hundred and seventy-four (22.5%) specimens showed the presence of bacteria, 42 (2.5%) had red blood cells, 370 (22.3%) had epithelial cells, 58 (3.5%) had crystals, and 14 (0.8%) had yeasts. The most common bacterium isolated was Escherichia coli (12; 40%); the others included group B Streptococcus (5; 15%), Klebsiella spp (5; 15%), Diphtheroids (2), and Candida albicans (2). Fifty-two percent of tested strains were sensitive to ampicillin; 24 of 28 strains (85.7%) were sensitive to ciprofloxacin; all 7 strains tested were sensitive to nitrofurantoin and all 20 strains tested were sensitive to cotrimoxazole; 14/20 (70%) and 16/17 (94.1%) were sensitive to cephalexin and cefuroxime respectively. This study shows that asymptomatic bacteriuria does occur in pregnant women, albeit at a very low rate in an urban setting like Cheras. Urine microscopy is not specific and only serves as a guide to bacteriuria. The commonest causative organisms are those from the gastrointestinal tract and vagina. The antibiogram showed that cefuroxime and cephalexin are likely to be effective in treating bacteriuria: ampicillin must be reserved for Gram-negative organisms. For Gram-positive organisms, of which Group B Streptococcus is important, ampicillin is still effective in vitro

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

PubMed

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.

Insertion Sequence-Caused Large Scale-Rearrangements in the Genome of Escherichia coli

DTIC Science & Technology

2016-07-18

rearrangements in the genome of Escherichia coli Heewook Lee1,2, Thomas G. Doak3,4, Ellen Popodi3, Patricia L. Foster3 and Haixu Tang1,* 1School of...and excisions of IS elements and recombi- nation between homologous IS elements identified in a large collection of Escherichia coli mutation accu...scale rear- rangements arose in the Escherichia coli genome during a long-term evolution experiment in a recent study (8). Com- bining WGSS with

Growth and maintenance of Escherichia coli laboratory strains.

PubMed

Son, Mike S; Taylor, Ronald K

2012-11-01

Escherichia coli is a Gram-negative bacterium, commonly used in both teaching and research laboratories. This unit includes protocols for the growth and maintenance of E. coli in any teaching- or research-associated laboratory. © 2012 by John Wiley & Sons, Inc.

Prevalence of asymptomatic bacteriuria and its consequences in pregnancy in a rural community of Bangladesh.

PubMed

Ullah, M Anayet; Barman, A; Siddique, M A; Haque, A K M E

2007-08-01

This was a cross-sectional followed by cohort type of study conducted among the pregnant mothers of second trimester in the rural areas of Rajshahi district. Initially 1800 pregnant mothers ofsecond trimester were selected from 18 unions applying 2-stage random sampling. A total of 216 pregnant mothers with asymptomatic bacteriuria were paired among the rest of the healthy pregnant mothers (without bacteriuria) on the basis of age, gravida and economic status for cohort study to relate asymptomatic bacteriuria with the incidence of symptomatic bacteriuria, hypertensive disorders in pregnancy (HDP) and pre-term delivery. The matched paired pregnant mothers werefollowed monthly interval up to delivery. The prevalence of asymptomatic bacteriuria was 12% among the pregnant mothers in rural Rajshahi. E. Coli was the commonest causative agent of both asymptomatic and symptomatic bacteriuria. The results of this study suggest that asymptomatic bacteriuria were more prone to develop symptomatic bacteriuria, hypertensive disorders in pregnancy and pre-term delivery than that of the healthy mothers (without bacteriuria). Screening of bacteriuria in pregnancy and proper treatment must be considered as an essential part of antenatal care in this rural community.

Giant Cells of Escherichia coli

PubMed Central

Adler, Howard I.; Terry, Claude E.; Hardigree, Alice A.

1968-01-01

A mutant strain of Escherichia coli K-12 produced amorphous cells when grown in a variety of media. The lon− allele, known to increase the radiation sensitivity of the cytokinesis mechanism, was introduced into the mutant by means of conjugation. Cells of this recombinant strain grew, after exposure to radiation, into giant amorphous cells, approximately 500 to 1,000 times the volume of a normal E. coli cell. These giant cells are analogous to the filaments formed after the irradiation of lon− rod-shaped cells. Images PMID:4866096

Methane production from kitchen waste using Escherichia coli.

PubMed

Jayalakshmi, S; Joseph, Kurian; Sukumaran, V

2007-04-01

Escherichia coli (E. coli) strain isolated from biogas plant sludge was examined for its ability to enhance biogas from kitchen waste during solid phase anaerobic digestion. The laboratory experiments were conducted for total solid concentrations of 20% and 22%. Kitchen waste was characterized for physico-chemical parameters and laboratory experiments were conducted with and without E. coli strain. It was found that the reactor with E. coli produced 17% more biogas than the reactors that are operated without E. coli strain.

Fosfomycin Resistance in Escherichia coli, Pennsylvania, USA.

PubMed

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.

Infection strategies of enteric pathogenic Escherichia coli

PubMed Central

Clements, Abigail; Young, Joanna C.; Constantinou, Nicholas; Frankel, Gad

2012-01-01

Enteric Escherichia coli (E. coli) are both natural flora of humans and important pathogens causing significant morbidity and mortality worldwide. Traditionally enteric E. coli have been divided into 6 pathotypes, with further pathotypes often proposed. In this review we suggest expansion of the enteric E. coli into 8 pathotypes to include the emerging pathotypes of adherent invasive E. coli (AIEC) and Shiga-toxin producing enteroaggregative E. coli (STEAEC). The molecular mechanisms that allow enteric E. coli to colonize and cause disease in the human host are examined and for two of the pathotypes that express a type 3 secretion system (T3SS) we discuss the complex interplay between translocated effectors and manipulation of host cell signaling pathways that occurs during infection. PMID:22555463

PmrD is Required for Modifications to Escherichia Coli Endotoxin that Promote Antimicrobial Resistance

DTIC Science & Technology

2015-01-20

is unlimited. PmrD Is Required for Modifications to Escherichia coli Endotoxin That Promote Antimicrobial Resistance The views, opinions and/or...East 27th Street Suite 5.300 Austin, TX 78712 -1532 ABSTRACT PmrD Is Required for Modifications to Escherichia coli Endotoxin That Promote...PhoPQ and PmrAB in E. coli than previously understood. PmrD Is Required for Modifications to Escherichia coli Endotoxin That Promote Antimicrobial

21 CFR 866.3255 - Escherichia coli serological reagents.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Escherichia coli serological reagents. 866.3255 Section 866.3255 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3255 Escherichia...

21 CFR 866.3255 - Escherichia coli serological reagents.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Escherichia coli serological reagents. 866.3255 Section 866.3255 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3255 Escherichia...

21 CFR 866.3255 - Escherichia coli serological reagents.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Escherichia coli serological reagents. 866.3255 Section 866.3255 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3255 Escherichia...

21 CFR 866.3255 - Escherichia coli serological reagents.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Escherichia coli serological reagents. 866.3255 Section 866.3255 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3255 Escherichia...

21 CFR 866.3255 - Escherichia coli serological reagents.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Escherichia coli serological reagents. 866.3255 Section 866.3255 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3255 Escherichia...

Slugs: potential novel vectors of Escherichia coli O157.

PubMed

Sproston, Emma L; Macrae, M; Ogden, Iain D; Wilson, Michael J; Strachan, Norval J C

2006-01-01

Field and laboratory studies were performed to determine whether slugs could act as novel vectors for pathogen (e.g., Escherichia coli O157) transfer from animal feces to salad vegetables. Escherichia coli O157 was isolated from 0.21% of field slugs from an Aberdeenshire sheep farm. These isolates carried the verocytotoxin genes (vt1 and vt2) and the attaching and effacing gene (eae), suggesting that they are potentially pathogenic to humans. Strain typing using multilocus variable number tandem repeats analysis showed that slug and sheep isolates were indistinguishable. Laboratory experiments using an E. coli mutant resistant to nalidixic acid showed that the ubiquitous slug species Deroceras reticulatum could carry viable E. coli on its external surface for up to 14 days. Slugs that had been fed E. coli shed viable bacteria in their feces with numbers showing a short but statistically significant linear log decline. Further, it was found that E. coli persisted for up to 3 weeks in excreted slug feces, and hence, we conclude that slugs have the potential to act as novel vectors of E. coli O157.

Genome dynamics and its impact on evolution of Escherichia coli.

PubMed

Dobrindt, Ulrich; Chowdary, M Geddam; Krumbholz, G; Hacker, J

2010-08-01

The Escherichia coli genome consists of a conserved part, the so-called core genome, which encodes essential cellular functions and of a flexible, strain-specific part. Genes that belong to the flexible genome code for factors involved in bacterial fitness and adaptation to different environments. Adaptation includes increase in fitness and colonization capacity. Pathogenic as well as non-pathogenic bacteria carry mobile and accessory genetic elements such as plasmids, bacteriophages, genomic islands and others, which code for functions required for proper adaptation. Escherichia coli is a very good example to study the interdependency of genome architecture and lifestyle of bacteria. Thus, these species include pathogenic variants as well as commensal bacteria adapted to different host organisms. In Escherichia coli, various genetic elements encode for pathogenicity factors as well as factors, which increase the fitness of non-pathogenic bacteria. The processes of genome dynamics, such as gene transfer, genome reduction, rearrangements as well as point mutations contribute to the adaptation of the bacteria into particular environments. Using Escherichia coli model organisms, such as uropathogenic strain 536 or commensal strain Nissle 1917, we studied mechanisms of genome dynamics and discuss these processes in the light of the evolution of microbes.

Sterilization by Cooling in Isochoric Conditions: The Case of Escherichia coli

PubMed Central

Salinas-Almaguer, Samuel; Angulo-Sherman, Abril; Sierra-Valdez, Francisco Javier; Mercado-Uribe, Hilda

2015-01-01

High hydrostatic pressure (HHP) affects the structure, metabolism and survival of micro-organisms including bacteria. For this reason HHP is a promising treatment in the food industry. The aim of this work is to evaluate the effect of high pressure, under isochoric cooling conditions, on Escherichia coli, where such high pressure develops due to the fact water cannot expand. We combine survival curves obtained by spectrophotometry and images of atomic force microscopy in this study. Our results show that cooling at -20 and -30°C leads to a partial destruction of a Escherichia coli population. However, cooling at -15°C causes a total extermination of bacteria. This intriguing result is explained by the phase diagram of water. In the first case, the simultaneous formation of ice III and ice Ih crystals provides a safe environment for bacteria. In the second case (-15°C) Escherichia coli remains in a metastable and amorphous free-of-crystals liquid subjected to high pressure. Our work is the first experimental study carried out to inactivate Escherichia coli under isochoric cooling conditions. Unlike HHP, which is based on the application of an external load to augment the pressure, this technique only requires cooling. The method could be used for annihilation of other Escherichia coli strains and perhaps other micro-organisms. PMID:26480032

Risk Factors Analysis for Occurrence of Asymptomatic Bacteriuria After Endourological Procedures

PubMed Central

Junuzovic, Dzelaludin; Hasanbegovic, Munira

2014-01-01

Introduction: Endourological procedures are performed according to the principles of aseptic techniques, jet still in certain number of patients urinary tract infections may occur. Considering the risk of urinary tract infection, there is no unique opinion about the prophylactic use of antibiotics in endourological procedures. Goal: The objective of this study was to determine the connection between endourological procedures and occurrence of urinary infections and to analyze the risk factors of urinary infection for patients who were hospitalized at the Urology Clinic of the Clinical Center University of Sarajevo CCUS. Materials and Methods: The research was conducted as a prospective study on a sample of 208 patients of both genders, who were hospitalized at the Urology Clinic of the CCUS and to whom some endourological procedure was indicated for diagnostic or therapeutic purposes. We analyzed data from patient’s histories of illness, laboratory tests taken at admission and after endourological procedures, also surgical programs for endoscopic procedures. All patients were clinically examined prior to endoscopic procedures while after the treatment attention was focused to the symptoms of urinary tract infections. Results: Statistical analysis of the tested patients indicates that there is no significant difference in the presence of postoperative, compared to preoperative bacteriuria, which implies that the endourological procedures are safe procedures in terms of urinary tract infections. Preoperatively, the most commonly isolated bacteria was Escherichia coli (30.9%) and postoperatively, Enterococcus faecalis (25%). Statistically significant effect on the occurrence of postoperative bacteriuria has preoperative bacteriuria, duration of postoperative catheterization, and duration of hospitalization. Conclusion: In everyday urological practice, it is very important to identify and control risk factors for the development of urinary infection after

Escherichia coli gamma-glutamyltranspeptidase mutants deficient in processing to subunits.

PubMed

Hashimoto, W; Suzuki, H; Nohara, S; Kumagai, H

1992-11-30

Arginyl residues 513 and 571 of Escherichia coli K-12 gamma-glutamyl-transpeptidase (EC 2.3.2.2) were substituted with alanyl and glycyl residues, respectively, by oligonucleotide-directed in vitro mutagenesis. Both mutants were devoid of the enzymatic activity. On Western blot analysis, we found that both mutants accumulated a gamma-glutamyltranspeptidase precursor which was not processed into large and small subunits in the periplasmic space of Escherichia coli.

Slugs: Potential Novel Vectors of Escherichia coli O157

PubMed Central

Sproston, Emma L.; Macrae, M.; Ogden, Iain D.; Wilson, Michael J.; Strachan, Norval J. C.

2006-01-01

Field and laboratory studies were performed to determine whether slugs could act as novel vectors for pathogen (e.g., Escherichia coli O157) transfer from animal feces to salad vegetables. Escherichia coli O157 was isolated from 0.21% of field slugs from an Aberdeenshire sheep farm. These isolates carried the verocytotoxin genes (vt1 and vt2) and the attaching and effacing gene (eae), suggesting that they are potentially pathogenic to humans. Strain typing using multilocus variable number tandem repeats analysis showed that slug and sheep isolates were indistinguishable. Laboratory experiments using an E. coli mutant resistant to nalidixic acid showed that the ubiquitous slug species Deroceras reticulatum could carry viable E. coli on its external surface for up to 14 days. Slugs that had been fed E. coli shed viable bacteria in their feces with numbers showing a short but statistically significant linear log decline. Further, it was found that E. coli persisted for up to 3 weeks in excreted slug feces, and hence, we conclude that slugs have the potential to act as novel vectors of E. coli O157. PMID:16391036

Isolating Escherichia coli strains for recombinant protein production.

PubMed

Schlegel, Susan; Genevaux, Pierre; de Gier, Jan-Willem

2017-03-01

Escherichia coli has been widely used for the production of recombinant proteins. To improve protein production yields in E. coli, directed engineering approaches have been commonly used. However, there are only few reported examples of the isolation of E. coli protein production strains using evolutionary approaches. Here, we first give an introduction to bacterial evolution and mutagenesis to set the stage for discussing how so far selection- and screening-based approaches have been used to isolate E. coli protein production strains. Finally, we discuss how evolutionary approaches may be used in the future to isolate E. coli strains with improved protein production characteristics.

[Outbreaks caused by diarrheagenic Escherichia coli].

PubMed

Vila Estapé, Jordi; Zboromyrska, Yuliya

2012-02-01

Escherichia coli are ubiquitous bacteria from a wide variety of ecosystems including the gastrointestinal tract of humans and warm-blooded animals. E. coli can play a role as an opportunistic bacteria causing a variety of infectious diseases including, among many others, sepsis, urinary tract infections, meningitis, and wound infections. Moreover, these bacteria can also act as primary pathogens in the intestinal tract. There are several pathotypes of E. coli that cause enteritis, and both sporadic cases and outbreaks have been reported. In this article, we review the pathogenicity and epidemiology of enteritis caused by these E. coli pathotypes, and provide some examples of outbreaks described in the scientific literature and the measures required to prevent them. Copyright © 2011 Elsevier España, S.L. All rights reserved.

Escherichia coli Pyomyositis in an Immunocompromised Host

PubMed Central

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

2015-01-01

Background Pyomyositis due to Escherichia coli (E. coli) is rarely reported in immunocompromised patients with hematological malignancy. Case Report 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. Conclusion 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. PMID:22413629

ISOLEUCINE AND VALINE METABOLISM IN ESCHERICHIA COLI XI. K-12

PubMed Central

Leavitt, Richard I.; Umbarger, H. E.

1962-01-01

Leavitt, Richard I. (Harvard Medical School, Boston, Mass.) and H. E. Umbarger. Isoleucine and valine metabolism in Escherichia coli. XI. Valine inhibition of the growth of Escherichia coli strain K-12. J. Bacteriol. 83:624–630. 1962.—The inhibition of the growth of Escherichia coli strain K-12 by valine was shown to be due to the sensitivity of the acetohydroxybutyrate-forming system to valine. It was demonstrated that both E. coli strain W, a strain whose growth is unaffected by valine, and a valine-resistant mutant of strain K-12 have acetolactate- and acetohydroxybutyrate-forming systems which are less sensitive to valine than that of strain K-12. It was further shown that α-aminobutyrate accumulates in the culture fluid of the valine-sensitive strain when incubated in the presence of valine. The levels of valine in the “free amino acid pool” were examined and found to be related to the differences in valine sensitivity of the acetolactate-forming systems of the three strains. PMID:14463257

New hemolysin (gamma) produced by Escherichia coli.

PubMed

Walton, J R; Smith, D H

1969-04-01

A new hemolysin (gamma) of Escherichia coli, active in the absence of viable bacteria, has been recognized in mutants resistant to nalidixic acid. Nalidixic acid affects either the production or release of the hemolysin.

Enteroaggregative Escherichia coli strains secrete a heat-labile toxin antigenically related to E. coli hemolysin.

PubMed Central

Baldwin, T J; Knutton, S; Sellers, L; Hernandez, H A; Aitken, A; Williams, P H

1992-01-01

A protein toxin of approximately 120,000 Da secreted by nonhemolytic enteroaggregative Escherichia coli strains cross-reacted in Western blots (immunoblots) with antibodies raised against the C-terminal region of E. coli hemolysin. Treatment of HEp-2 cells with enteroaggregative E. coli or culture supernatants caused elevation of intracellular calcium and stimulated calcium-dependent protein phosphorylation. Images PMID:1563799

Epigenetic Mechanisms Regulate Innate Immunity against Uropathogenic and Commensal-Like Escherichia coli in the Surrogate Insect Model Galleria mellonella.

PubMed

Heitmueller, Miriam; Billion, André; Dobrindt, Ulrich; Vilcinskas, Andreas; Mukherjee, Krishnendu

2017-10-01

Innate-immunity-related genes in humans are activated during urinary tract infections (UTIs) caused by pathogenic strains of Escherichia coli but are suppressed by commensals. Epigenetic mechanisms play a pivotal role in the regulation of gene expression in response to environmental stimuli. To determine whether epigenetic mechanisms can explain the different behaviors of pathogenic and commensal bacteria, we infected larvae of the greater wax moth, Galleria mellonella , a widely used model insect host, with a uropathogenic E. coli (UPEC) strain that causes symptomatic UTIs in humans or a commensal-like strain that causes asymptomatic bacteriuria (ABU). Infection with the UPEC strain (CFT073) was more lethal to larvae than infection with the attenuated ABU strain (83972) due to the recognition of each strain by different Toll-like receptors, ultimately leading to differential DNA/RNA methylation and histone acetylation. We used next-generation sequencing and reverse transcription (RT)-PCR to correlate epigenetic changes with the induction of innate-immunity-related genes. Transcriptomic analysis of G. mellonella larvae infected with E. coli strains CFT073 and 83972 revealed strain-specific variations in the class and expression levels of genes encoding antimicrobial peptides, cytokines, and enzymes controlling DNA methylation and histone acetylation. Our results provide evidence for the differential epigenetic regulation of transcriptional reprogramming by UPEC and ABU strains of E. coli in G. mellonella larvae, which may be relevant to understanding the different behaviors of these bacterial strains in the human urinary tract. Copyright © 2017 American Society for Microbiology.

Escherichia coli pyomyositis in an immunocompromised host.

PubMed

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.

Characterization of Escherichia coli and other Enterobacteriaceae in producer-distributor bulk milk.

PubMed

Ntuli, V; Njage, P M K; Buys, E M

2016-12-01

The current study was undertaken to characterize Escherichia coli and other Enterobacteriaceae in raw and pasteurized producer-distributor bulk milk (PDBM). A total of 258 samples were collected from purchase points in 8 provinces in South Africa. The samples were tested for antibiotic residues, phosphatase, total aerobic bacteria, coliforms, and E. coli counts. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used for identification of isolates. Escherichia coli isolates were characterized for virulence factors, antimicrobial resistance, serotypes, and presumptive E. coli O157:H7. Antibiotic residues and alkaline phosphatase were detected in 2% of both raw and pasteurized PDBM (n=258) and 21% pasteurized PDBM (n=104) samples, respectively. A total of 729 isolates belonging to 21 genera and 59 species were identified. Escherichia coli, Enterobacter cloacae, Klebsiella oxytoca, and Raoultella ornithinolytica were the most abundant species. Spoilage Enterobacteriaceae species exceeded 50% of the total isolates. Escherichia coli was detected and isolated from 36% of the milk samples. Thirty-one E. coli isolates harbored virulence genes stx1/stx2 and 38% (n=121) were presumptive O157:H7. The prevalence of samples with presumptive shigatoxin producing E. coli was 10%. Antimicrobial-resistant E. coli isolates were detected in 70% of the milk samples with 36% of stx1/stx2 positive E. coli showing multi-drug resistance. Information obtained from the study will be used for modeling the public health risk posed by milkborne pathogens in PDBM, which in many cases is consumed by poor and vulnerable members of the population. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Aging of Escherichia coli

PubMed Central

Clifton, C. E.

1966-01-01

Clifton, C. E. (Stanford University, Stanford, Calif.). Aging of Escherichia coli. J. Bacteriol. 92:905–912. 1966.—The rates of endogenous and exogenous (glucose) respiration decreased much more rapidly than did the viable count during the first 24 hr of aging of washed, C14-labeled cells of Escherichia coli K-12 suspended in a basal salt medium devoid of ammonium salts. The rates of decrease of respiration and of death approached each other as the age of the cells increased, but death was not the only factor involved in decreased respiratory activity of the suspensions. The greatest decrease in cellular contents with aging was noted in the ribonucleic acid fraction, of which the ribose appeared to be oxidized, while uracil accumulated in the suspension medium. The viable count and respiratory activities remained higher in glucose-fed than in nonfed suspensions. Proline-labeled cells fed glucose tended to lose more of their proline and to convert more proline into C14O2 than in unfed controls. On the other hand, uracil-labeled cells fed glucose retained more of the uracil than did nonfed cells, but glucose elicited some oxidation of uracil. An exogenous energy source such as glucose aided in the maintenance of a population, but it was not the only factor needed for such maintenance. PMID:5332874

New Hemolysin (γ) Produced by Escherichia coli

PubMed Central

Walton, John R.; Smith, David H.

1969-01-01

A new hemolysin (γ) of Escherichia coli, active in the absence of viable bacteria, has been recognized in mutants resistant to nalidixic acid. Nalidixic acid affects either the production or release of the hemolysin. Images PMID:4891808

Evaluation and importance of asymptomatic bacteriuria in pregnancy.

PubMed

Tugrul, S; Oral, O; Kumru, P; Köse, D; Alkan, A; Yildirim, G

2005-01-01

This study was undertaken to determine the incidence of asymptomatic bacteriuria (ASB) during pregnancy and its prevalance in the three trimesters. One hundred and ten pregnant women in their first trimester attending the antenatal outpatient clinic with no urinary tract complaints were included in the study. After perineal cleaning, urine samples were obtained from all patients for culture and microscopic evaluation. Approximately 1 ml urine was sampled using the mid-stream catch technique. Patients with bacterial counts over 100,000 with the mid-stream catch technique were considered to have asymptomatic bacteriuria. Patients fulfilling the criteria for bacteriuria were treated with either penicillin or cephalosporine for one week, depending on the in-vitro sensitivity test results. ASB rate in the study group was 8.1%. E. coli was isolated as the pathogenic organism in 77.77% of the cases with ASB. ASB was found to be more frequent in patients over age 25 and the average age of pregnant women with ASB was 29.89 +/- 5.80 (p < 0.05). Average duration of gestation in the group with ASB was 28.11 +/- 2.26 weeks. ASB rate in the group age 35 and over was 22.22% (p < 0.05). ASB was diagnosed in nine patients; one of these patients was in the first trimester, two were in the second trimester, and six in the third trimester. Clustering in the third trimester was found to be statistically significant (p < 0.05). ASB distribution in the first, second, and third trimesters was 0.9%, 1.83%, and 5.6%, respectively. There was a significant relationship between advanced maternal age and incidence of ASB. Women with no bacteriuria in their initial examination in the first trimester developed bacteriuria in the later trimesters. We, therefore, suggest that it would be prudent to screen pregnant women for bacteriuria in the second and third trimesters.

Genome Sequence of Enterohemorrhagic Escherichia coli NCCP15658

PubMed Central

Song, Ju Yeon; Yoo, Ran Hee; Jang, Song Yee; Seong, Won-Keun; Kim, Seon-Young; Jeong, Haeyoung; Kang, Sung Gyun; Kim, Byung Kwon; Kwon, Soon-Kyeong; Lee, Choong Hoon; Yu, Dong Su; Park, Mi-Sun

2012-01-01

Enterohemorrhagic Escherichia coli causes severe food-borne disease in the guts of humans and animals. Here, we report the high-quality draft genome sequence of E. coli NCCP15658 isolated from a patient in the Republic of Korea. Its genome size was determined to be 5.46 Mb, and its genomic features, including genes encoding virulence factors, were analyzed. PMID:22740673

Genome Sequence of the Enterohemorrhagic Escherichia coli Bacteriophage UFV-AREG1

PubMed Central

Batalha, Laís Silva; Albino, Luiz Augusto A.; Boggione, Delaine Meireles Gouveia; Gontijo, Marco Tulio Pardini; Bazzolli, Denise M. Soares; Mendonca, Regina C. Santos

2016-01-01

Here, we present the genome sequence of the Escherichia coli bacteriophage UFV-AREG1. This phage was isolated from cowshed wastewater and showed specificity for enterohemorrhagic E. coli O157:H7 (ATCC 43895), E. coli 0111 (CDC O11ab) and E. coli (ATCC 23229). PMID:27738021

[Characterization of ibeB gene of meningitic Escherichia coli strains in calves from Xinjiang].

PubMed

Ling, Chen; Jiang, Jianjun; Song, Kang; Zhang, Kun; Shi, Yanxia; Feng, Guangyu; Ni, Hongbin; Zhu, Ling; Wang, Pengyan; Yan, Genqiang

2016-06-04

To understand the molecular biology information of ibeB gene of meningitic Escherichia coli isolates in calves. The strain used was isolated from the brain and liver tissue of calves died from Meningitis. It was identified to be an O161-K99-STa pathogenic Escherichia coli strain and named as bovine-EN and bovine-EG. Based on the sequence of ibeB gene of meningitic Escherichia coli K1 RS218 strain in GenBank, a pair of primers was designed and the ibeB gene was cloned from isolates by PCR. Part molecular biology information of ibeB among different strains was compared. The sequence length of isolates ibeB gene was 1500 bp, containing a 1371 bp open reading frame (ORF) encoding 457 amino acids. Bioinformatics analysis showed that the nucleotide and amino acid homology of ibeB gene of bovine-EN strain shared 90.5% and 96.9% identity with Escherichia coli K1 RS218 ibeB gene, respectively, while bovine-EG strain shared 99.4% and 100.0% identity with Escherichia coli K12 respectively. The ibeB gene of bovine-E strains encoded water-soluble protein whose molecular weight was 50.26 kDa and isoelectric point was 6.05. This protein contained a signal peptide A but no transmembrane domain. Subcellular localization of ibeB belonged to the secreted protein, which secretory signal path site (SP) proportion was 0.939. The ibeB gene was cloned from meningitic E. coli isolates and had higher homology and similar biological characteristics with meningitis E. coli K1 RS218ibeB, which belongs to extraintestinal pathogenic Escherichia coli.

Predictors Of Non-Escherichia Coli Urinary Tract Infection.

PubMed

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.

Escherichia Coli--Key to Modern Genetics.

ERIC Educational Resources Information Center

Bregegere, Francois

1982-01-01

Mid-nineteenth century work by Mendel on plant hybrids and by Pasteur on fermentation gave birth by way of bacterial genetics to modern-day molecular biology. The bacterium Escherichia Coli has occupied a key position in genetic studies leading from early gene identification with DNA to current genetic engineering using recombinant DNA technology.…

Inactivation of Escherichia coli by citral.

PubMed

Somolinos, M; García, D; Condón, S; Mackey, B; Pagán, R

2010-06-01

The aim was to evaluate (i) the resistance of Escherichia coli BJ4 to citral in a buffer system as a function of citral concentration, treatment medium pH, storage time and initial inoculum size, (ii) the role of the sigma factor RpoS on citral resistance of E. coli, (iii) the role of the cell envelope damage in the mechanism of microbial inactivation by citral and (iiii) possible synergistic effects of mild heat treatment and pulsed electric fields (PEF) treatment combined with citral. The initial inoculum size greatly affected the efficacy of citral against E. coli cells. Exposure to 200 microl l(-1) of citral at pH 4.0 for 24 h at 20 degrees C caused the inactivation of more than 5 log(10) cycles of cells starting at an inoculum size of 10(6) or 10(7) CFU ml(-1), whereas increasing the cell concentration to 10(9) CFU ml(-1) caused <1 log(10) cycle of inactivation. Escherichia coli showed higher resistance to citral at pH 4.0 than pH 7.0. The rpoS null mutant strain E. coli BJ4L1 was less resistant to citral than the wild-type strain. Occurrence of sublethal injury to both the cytoplasmic and outer membranes was demonstrated by adding sodium chloride or bile salts to the recovery media. The majority of sublethally injured cells by citral required energy and lipid synthesis for repair. A strongly synergistic lethal effect was shown by mild heat treatment combined with citral but the presence of citral during the application of a PEF treatment did not show any advantage. This work confirms that cell envelope damage is an important event in citral inactivation of bacteria, and it describes the key factors on the inactivation of E. coli cells by citral. Knowledge about the mechanism of microbial inactivation by citral helps establish successful combined preservation treatments.

Escherichia coli as a glycoprotein production host: recent developments and challenges.

PubMed

Jaffé, Stephen R P; Strutton, Benjamin; Levarski, Zdenko; Pandhal, Jagroop; Wright, Phillip C

2014-12-01

Chinese Hamster Ovary cells are the most popular host expression system for the large-scale production of human therapeutic glycoproteins, but, the race to engineer Escherichia coli to perform glycosylation is gathering pace. The successful functional transfer of an N-glycosylation pathway from Campylobacter jejuni to Escherichia coli in 2002 can be considered as the crucial first engineering step. Here, we discuss the recent advancements in the field of N-glycosylation of recombinant therapeutic proteins in E. coli cells, from the manipulation of glycan composition, to the improvement in glycosylation efficiency, along with the challenges that remain before E. coli can be available as an industry host cell for economically viable glycoprotein production. Copyright © 2014 Elsevier Ltd. All rights reserved.

Growth modeling of uropathogenic Escherichia coli in ground chicken meat

USDA-ARS?s Scientific Manuscript database

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...

Toward Development of an Oral, Plant-Based Vaccine Against Escherichia coli O157:H7

DTIC Science & Technology

2004-01-01

Mason, H. S., Haq, T. A., Clements, J. D., and Arntzen, C. J. (1998). Edible vaccine protects mice against Escherichia coli heat-labile enterotoxin (LT...based Vaccine Against Escherichia coli O157:H7.” beyond brief excerpts is with the permission of the copyright owner, and will save and hold...4. TITLE AND SUBTITLE Toward Development of an Oral, Plant-based Vaccine Against Escherichia coli O157:H7 5a. CONTRACT NUMBER 5b. GRANT

Hydrogen production by recombinant Escherichia coli strains

PubMed Central

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

Asymptomatic bacteriuria in pregnancy.

PubMed

Smaill, Fiona

2007-06-01

Screening for asymptomatic bacteriuria is a standard of obstetrical care and is included in most antenatal guidelines. There is good evidence that treatment of asymptomatic bacteriuria will decrease the incidence of pyelonephritis. All pregnant women should be screened for asymptomatic bacteriuria, and there are no new data that would indicate otherwise. Antibiotic treatment of asymptomatic bacteriuria is associated with a decrease in the incidence of preterm delivery or low birth weight, but the methodological quality of the studies means any conclusion about the strength of this association needs to be drawn cautiously. A better understanding of the mechanism by which treatment of asymptomatic bacteriuria could prevent preterm delivery is needed. While several rapid screening tests have been evaluated, none perform adequately to replace urine culture for detecting asymptomatic bacteriuria. Until there are data from well-designed trials that establish the optimal duration of therapy for asymptomatic bacteriuria, standard treatment courses are recommended.

Prevalence and Association of Escherichia coli and Diarrheagenic Escherichia coli in Stored Foods for Young Children and Flies Caught in the Same Households in Rural Bangladesh

PubMed Central

Doza, Solaiman; Jabeen Rahman, Musarrat; Islam, Mohammad Aminul; Kwong, Laura H.; Unicomb, Leanne; Ercumen, Ayse; Pickering, Amy J.; Parvez, Sarker Masud; Naser, Abu Mohd; Ashraf, Sania; Das, Kishor Kumar; Luby, Stephen P.

2018-01-01

Abstract. Consumption of contaminated stored food can cause childhood diarrhea. Flies carry enteropathogens, although their contribution to food contamination remains unclear. We investigated the role of flies in contaminating stored food by collecting food and flies from the same households in rural Bangladesh. We selected 182 households with children ≤ 24 months old that had stored foods for later feeding at room temperature for ≥ 3 hours. We collected food samples and captured flies with fly tapes hung by the kitchen. We used the IDEXX Quanti-Tray System (Colilert-18 media; IDEXX Laboratories, Inc., Westbrook, ME) to enumerate Escherichia coli with the most probable number (MPN) method. Escherichia coli–positive IDEXX wells were analyzed by polymerase chain reaction for pathogenic E. coli genes (eae, ial, bfp, ipaH, st, lt, aat, aaiC, stx1, and stx2). Escherichia coli was detected in 61% (111/182) of food samples, with a mean of 1.1 log10 MPN/dry g. Fifteen samples (8%) contained pathogenic E. coli; seven (4%) had enteropathogenic E. coli (EPEC) genes (eae and/or bfp); and 10 (5%) had enteroaggregative E. coli genes (aat and/or aaiC). Of flies captured in 68 (37%) households, E. coli was detected in 41 (60%, mean 2.9 log10 MPN/fly), and one fly (1%) had an EPEC gene (eae). For paired fly-food samples, each log10 MPN E. coli increase in flies was associated with a 0.31 log10 MPN E. coli increase in stored food (95% confidence interval: 0.07, 0.55). In rural Bangladesh, flies possibly a likely route for fecal contamination of stored food. Controlling fly populations may reduce contamination of food stored for young children. PMID:29436348

The antimicrobial activity of probiotic bacteria Escherichia coli isolated from different natural sources against hemorrhagic E. coli O157:H7.

PubMed

Karimi, Sahar; Azizi, Fatemeh; Nayeb-Aghaee, Mohammad; Mahmoodnia, Leila

2018-03-01

Diarrheal diseases have been seen in all geographical areas throughout the world. Therefore, considering treatment, could be deemed a necessary action. The aim of this study was to determine the antimicrobial effect of probiotic bacterial strains isolated from different natural sources against 2 pathotypes of pathogenic E. coli. This cross-sectional study of Martyr Chamran University of Ahvaz was carried out from December 2013 to July 2014. A total of 13 probiotic colonies isolated from 20 samples of traditional dairy products including (yogurt, cheese, milk) and 20 samples of vegetables including carrots and cabbages (red and white) of which 5 isolates were selected to evaluate the antimicrobial effect against 2 Escherichia coli pathotypes, randomly. Antimicrobial effect was evaluated using two methods: disk diffusion and well diffusion tests and measuring growth inhibition zones of probiotics against 2 pathotypes of pathogenic E. coli. Obtained results showed growth inhibition effects of all 5 probiotic strains against Escherichia coli pathotypes in both used methods. All selected strains showed considerable antimicrobial effect on Escherichia coli O157:H7 strain, but had no inhibitory effect against Enterohemorrhagic Escherichia coli. This study demonstrated considerable antimicrobial effect against E. coli O157:H7 strain. Due to this, characteristic and similar antimicrobial effects of probiotics bacteria, increasing use of the probiotics as a natural and modern method for prevention of different diseases is recommended.

Phenotypic Profiles of Enterotoxigenic Escherichia coli Associated With Early Childhood Diarrhea in Rural Egypt

DTIC Science & Technology

2004-12-01

2004, American Society for Microbiology. All Rights Reserved. Phenotypic Profiles of Enterotoxigenic Escherichia coli Associated with Early Childhood...Enterotoxigenic Escherichia coli (ETEC) causes substantial diarrheal morbidity and mortality in young children in countries with limited resources. We...expressed both toxins. The most common CF phenotypes were colonization factor antigen I (CFA/I) (10%), coli surface antigen 6 (CS6) (9%), CS14 (6%), and

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

USGS Publications Warehouse

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.

Multiplex PCR for Diagnosis of Enteric Infections Associated with Diarrheagenic Escherichia coli

PubMed Central

Vidal, Roberto; Vidal, Maricel; Lagos, Rossana; Levine, Myron; Prado, Valeria

2004-01-01

A multiplex PCR for detection of three categories of diarrheagenic Escherichia coli was developed. With this method, enterohemorrhagic E. coli, enteropathogenic E. coli, and enterotoxigenic E. coli were identified in fecal samples from patients with hemorrhagic colitis, watery diarrhea, or hemolytic-uremic syndrome and from food-borne outbreaks. PMID:15071051

Escherichia coli Field Contamination of Pecan Nuts

PubMed Central

Marcus, Karen A.; Amling, H. J.

1973-01-01

More pecan samples collected from grazed orchards were contaminated with Escherichia coli than were samples from nongrazed orchards. No differences in frequency of contamination between mechanically and manually harvested nuts occurred. Nutmeats from whole uncracked pecans that were soaked for 24 h in a lactose broth solution containing E. coli did not become contaminated. Twentyfour percent of the whole pecans soaked in water for 48 h to simulate standing in a rain puddle developed openings along shell suture lines which did not completely close when the nuts were redried. PMID:4584575

Prevalence, aetiology and antibiotic sensitivity profile of asymptomatic bacteriuria isolates from pregnant women in selected antenatal clinic from Nairobi, Kenya.

PubMed

Ayoyi, Adelaide Ogutu; Kikuvi, Gideon; Bii, Christine; Kariuki, Samuel

2017-01-01

Asymptomatic bacteriuria (ASB) is the presence of bacteria in urine without apparent symptoms of urinary tract infections. The importance of asymptomatic bacteriuria lies in the insight it provides into symptomatic infections. To determine prevalence, bacterial isolates and Antibiotic Sensitivity Profile of asymptomatic bacterial urinary tract infection in pregnant women in selected clinics in Nairobi. This was a cross-sectional study involving women attending antenatal clinic at selected clinics of Nairobi County. The women who met the inclusion criteria were included in the study. The midstream urine samples of these women were subjected to microscopy, culture and sensitivity. A total of 1020 of women on their first antenatal clinic visit participated in the study; 219 of them had ASB, giving a prevalence of 21.5 % at 95% confidence level. Escherichia coli were the common organism isolated at 38.8%. The majority of the organisms were sensitive to imipenem and gentamycin. There is a high prevalence of ASB among pregnant women included in the study from the Nairobi county clinics. Therefore, routine ASB screening of pregnant women is recommended among the women attending antennal clinics in Nairobi county clinics.

Prevalence, aetiology and antibiotic sensitivity profile of asymptomatic bacteriuria isolates from pregnant women in selected antenatal clinic from Nairobi, Kenya

PubMed Central

Ayoyi, Adelaide Ogutu; Kikuvi, Gideon; Bii, Christine; Kariuki, Samuel

2017-01-01

Introduction Asymptomatic bacteriuria (ASB) is the presence of bacteria in urine without apparent symptoms of urinary tract infections. The importance of asymptomatic bacteriuria lies in the insight it provides into symptomatic infections. To determine prevalence, bacterial isolates and Antibiotic Sensitivity Profile of asymptomatic bacterial urinary tract infection in pregnant women in selected clinics in Nairobi. Methods This was a cross-sectional study involving women attending antenatal clinic at selected clinics of Nairobi County. The women who met the inclusion criteria were included in the study. The midstream urine samples of these women were subjected to microscopy, culture and sensitivity. Results A total of 1020 of women on their first antenatal clinic visit participated in the study; 219 of them had ASB, giving a prevalence of 21.5 % at 95% confidence level. Escherichia coli were the common organism isolated at 38.8%. The majority of the organisms were sensitive to imipenem and gentamycin. Conclusion There is a high prevalence of ASB among pregnant women included in the study from the Nairobi county clinics. Therefore, routine ASB screening of pregnant women is recommended among the women attending antennal clinics in Nairobi county clinics. PMID:28451019

Gold nanoparticles as efficient antimicrobial agents for Escherichia coli and Salmonella typhi

PubMed Central

2013-01-01

Background It is imperative to eliminate bacteria present in water in order to avoid problems in healthy. Escherichia coli and Salmonella typhi bacteria are two common pollutants and they are developing resistance to some of the most used bactericide. Therefore new biocide materials are being tested. Thus, gold nanoparticles are proposed to inhibit the growth of these two microorganisms. Results Gold nanoparticles were supported onto clinoptilolite, mordenite and faujasite zeolites. Content of gold in materials varied between 2.3 and 2.8 wt%. The size, dispersion and roughness of gold nanoparticles were highly dependent of the zeolite support. The faujasite support was the support where the 5 nm nanoparticles were highly dispersed. The efficiency of gold-zeolites as bactericides of Escherichia coli and Salmonella typhi was determined by the zeolite support. Conclusions Gold nanoparticles dispersed on zeolites eliminate Escherichia coli and Salmonella typhi at short times. The biocidal properties of gold nanoparticles are influenced by the type of support which, indeed, drives key parameters as the size and roughness of nanoparticles. The more actives materials were pointed out Au-faujasite. These materials contained particles sized 5 nm at surface and eliminate 90–95% of Escherichia coli and Salmonella typhi colonies. PMID:23331621

One-day compared with 7-day nitrofurantoin for asymptomatic bacteriuria in pregnancy: a randomized controlled trial.

PubMed

Lumbiganon, Pisake; Villar, Jose; Laopaiboon, Malinee; Widmer, Mariana; Thinkhamrop, Jadsada; Carroli, Guillermo; Duc Vy, Nguyen; Mignini, Luciano; Festin, Mario; Prasertcharoensuk, Witoon; Limpongsanurak, Sompop; Liabsuetrakul, Tippawan; Sirivatanapa, Pannee

2009-02-01

To evaluate whether a 1-day nitrofurantoin regimen is as effective as a 7-day regimen in eradicating asymptomatic bacteriuria during pregnancy. A multicenter, double-blind, randomized, placebo controlled noninferiority trial was conducted in antenatal clinics in Thailand, the Philippines, Vietnam, and Argentina. Pregnant women seeking antenatal care between March 2004 and March 2007 who met the inclusion and exclusion criteria were invited to participate in the study. Those who consented were randomly allocated to receive either a 1-day or a 7-day course of 100 mg capsules of nitrofurantoin, which was taken twice daily. The primary outcome was bacteriologic cure on day 14 of treatment. : A total of 1,248 of 24,430 eligible women had asymptomatic bacteriuria, making the overall prevalence of 5.1%. Of these 1,248 women, 778 women were successfully recruited, and 386 and 392 women were randomly allocated to 1-day and 7-day regimens, respectively. Escherichia coli was the most common potentially pathogenic bacteria detected, its prevalence approaching 50%. Bacteriologic cure rates at treatment day 14 were 75.7% and 86.2% for 1-day and 7-day regimens, respectively. The cure rate difference was -10.5% (95% confidence interval -16.1% to -4.9%). Mean birth weight and mean gestational age at delivery were significantly lower in the 1-day regimen group. There were fewer adverse effects in the 1-day regimen group, but the differences were not statistically significant. A 1-day regimen of nitrofurantoin is significantly less effective than a 7-day regimen. Women with asymptomatic bacteriuria in pregnancy should receive the standard 7-day regimen. ISRCTN, isrctn.org, ISRCTN11966080 I.

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

PubMed

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.

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

PubMed Central

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

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

USDA-ARS?s Scientific Manuscript database

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...

Multidrug-resistant Escherichia coli in Asia: epidemiology and management.

PubMed

Sidjabat, Hanna E; Paterson, David L

2015-05-01

Escherichia coli has become multiresistant by way of production of a variety of β-lactamases. The prevalence of CTX-M-producing E. coli has reached 60-79% in certain parts of Asia. The acquisition of CTX-M plasmids by E. coli sequence type 131, a successful clone of E. coli, has caused further dissemination of CTX-M-producing E. coli. The prevalence of carbapenemase-producing E. coli, especially Klebsiella pneumoniae carbapenemase, and New Delhi metallo-β-lactamase (NDM)-producing E. coli has been increasing in Asia. K. pneumoniae carbapenemase and NDM have now been found in E. coli sequence type 131. The occurrence of NDM-producing E. coli is a major concern particularly in the Indian subcontinent, but now elsewhere in Asia as well. There are multiple reasons why antibiotic resistance in E. coli in Asia has reached such extreme levels. Approaches beyond antibiotic therapy, such as prevention of antibiotic resistance by antibiotic stewardship and protecting natural microbiome, are strategies to avoid further spread of antibiotic resistance.

Enterotoxigenic Escherichia coli infection in captive black-footed ferrets.

PubMed

Bradley, G A; Orr, K; Reggiardo, C; Glock, R D

2001-07-01

Enterotoxigenic Escherichia coli with genes for heat stabile toxins Sta and STb was isolated from the gastrointestinal tract and multiple visceral organs of three adult and three juvenile black-footed ferrets (Mustela nigripes) that died in a captive breeding colony between 24 May 1998 and 2 July 1998. Similar isolates were obtained from rectal swabs of one adult and one juvenile that were clinically ill. All were fed a diet composed of mink chow, raw rabbit meat, beef liver powder, blood meal and lard. Escherichia coli of the same toxin genotype was isolated from the mixed ration. Clinical signs included sudden death, dehydration, anorexia and diarrhea. Necropsy lesions included acute enteritis with large numbers of rod shaped bacteria microscopically visible on intestinal villi.

The quantitative and condition-dependent Escherichia coli proteome

PubMed Central

Schmidt, Alexander; Kochanowski, Karl; Vedelaar, Silke; Ahrné, Erik; Volkmer, Benjamin; Callipo, Luciano; Knoops, Kèvin; Bauer, Manuel; Aebersold, Ruedi; Heinemann, Matthias

2016-01-01

Measuring precise concentrations of proteins can provide insights into biological processes. Here, we use efficient protein extraction and sample fractionation and state-of-the-art quantitative mass spectrometry techniques to generate a comprehensive, condition-dependent protein abundance map of Escherichia coli. We measure cellular protein concentrations for 55% of predicted E. coli genes (>2300 proteins) under 22 different experimental conditions and identify methylation and N-terminal protein acetylations previously not known to be prevalent in bacteria. We uncover system-wide proteome allocation, expression regulation, and post-translational adaptations. These data provide a valuable resource for the systems biology and broader E. coli research communities. PMID:26641532

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

PubMed

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.

Diarrheagenic Escherichia coli in Children from Costa Rica

PubMed Central

Pérez, Cristian; Gómez-Duarte, Oscar G.; Arias, María L.

2010-01-01

More than 5,000 diarrheal cases per year receive medical care at the National Children's Hospital of Costa Rica, and nearly 5% of them require hospitalization. A total of 173 Escherichia coli strains isolated from children with diarrhea were characterized at the molecular, serologic, and phenotypic level. Multiplex and duplex polymerase chain reactions were used to detect the six categories of diarrheagenic E. coli. Thirty percent (n = 52) of the strains were positive, indicating a high prevalence among the pediatric population. Enteropathogenic E. coli and enteroinvasive E. coli pathotypes were the most prevalent (21% and 19%, respectively). Pathogenic strains were distributed among the four E. coli phylogenetic groups A, B1, B2, and D, with groups A and B1 the most commonly found. This study used molecular typing to evaluate the prevalence of diarrheagenic E. coli reported in Costa Rica and demonstrated the importance of these pathotypes in the pediatric population. PMID:20682870

Systems Metabolic Engineering of Escherichia coli.

PubMed

Choi, Kyeong Rok; Shin, Jae Ho; Cho, Jae Sung; Yang, Dongsoo; Lee, Sang Yup

2016-05-01

Systems metabolic engineering, which recently emerged as metabolic engineering integrated with systems biology, synthetic biology, and evolutionary engineering, allows engineering of microorganisms on a systemic level for the production of valuable chemicals far beyond its native capabilities. Here, we review the strategies for systems metabolic engineering and particularly its applications in Escherichia coli. First, we cover the various tools developed for genetic manipulation in E. coli to increase the production titers of desired chemicals. Next, we detail the strategies for systems metabolic engineering in E. coli, covering the engineering of the native metabolism, the expansion of metabolism with synthetic pathways, and the process engineering aspects undertaken to achieve higher production titers of desired chemicals. Finally, we examine a couple of notable products as case studies produced in E. coli strains developed by systems metabolic engineering. The large portfolio of chemical products successfully produced by engineered E. coli listed here demonstrates the sheer capacity of what can be envisioned and achieved with respect to microbial production of chemicals. Systems metabolic engineering is no longer in its infancy; it is now widely employed and is also positioned to further embrace next-generation interdisciplinary principles and innovation for its upgrade. Systems metabolic engineering will play increasingly important roles in developing industrial strains including E. coli that are capable of efficiently producing natural and nonnatural chemicals and materials from renewable nonfood biomass.

Systems Metabolic Engineering of Escherichia coli.

PubMed

Choi, Kyeong Rok; Shin, Jae Ho; Cho, Jae Sung; Yang, Dongsoo; Lee, Sang Yup

2017-03-01

Systems metabolic engineering, which recently emerged as metabolic engineering integrated with systems biology, synthetic biology, and evolutionary engineering, allows engineering of microorganisms on a systemic level for the production of valuable chemicals far beyond its native capabilities. Here, we review the strategies for systems metabolic engineering and particularly its applications in Escherichia coli. First, we cover the various tools developed for genetic manipulation in E. coli to increase the production titers of desired chemicals. Next, we detail the strategies for systems metabolic engineering in E. coli, covering the engineering of the native metabolism, the expansion of metabolism with synthetic pathways, and the process engineering aspects undertaken to achieve higher production titers of desired chemicals. Finally, we examine a couple of notable products as case studies produced in E. coli strains developed by systems metabolic engineering. The large portfolio of chemical products successfully produced by engineered E. coli listed here demonstrates the sheer capacity of what can be envisioned and achieved with respect to microbial production of chemicals. Systems metabolic engineering is no longer in its infancy; it is now widely employed and is also positioned to further embrace next-generation interdisciplinary principles and innovation for its upgrade. Systems metabolic engineering will play increasingly important roles in developing industrial strains including E. coli that are capable of efficiently producing natural and nonnatural chemicals and materials from renewable nonfood biomass.

Dihydroneopterin triphosphate epimerase of Escherichia coli: purification, genetic cloning, and expression.

PubMed Central

Haussmann, C; Rohdich, F; Lottspeich, F; Eberhardt, S; Scheuring, J; Mackamul, S; Bacher, A

1997-01-01

The enzyme catalyzing the epimerization at position 2' of dihydroneopterin triphosphate was purified by a factor of about 10,000 from cell extract of Escherichia coli. The cognate gene was cloned, sequenced, expressed, and mapped to kb 2427 on the E. coli chromosome. PMID:9006053

SURVIVAL OF ESCHERICHIA COLI 0157:H7 IN DAIRY CATTLE FEED WATER

EPA Science Inventory

Cattle feed waters from two dairy farms were used in a study to determine the survival characteristics of the bacterial pathogen Escherichia coli )157:H7 and wild-type E. coli. The E. coli 0157:H7 inoculum consisted of a consortium of isolates obtained from dairy cattle. Fresh ma...

Epidemiological and clinical complexity of amoxicillin-clavulanate-resistant Escherichia coli.

PubMed

Rodríguez-Baño, Jesús; Oteo, Jesús; Ortega, Adriana; Villar, Macarena; Conejo, M Carmen; Bou, Germán; Aranzamendi-Zaldumbide, Maitane; Cercenado, Emilia; Gurguí, Mercè; Martínez-Martínez, Luis; Merino, María; Rivera, Alba; Oliver, Antonio; Weber, Irene; Pascual, Alvaro; Bartolomé, Rosa M; Gónzalez-López, Juan José; Campos, José

2013-07-01

Two hundred twelve patients with colonization/infection due to amoxicillin-clavulanate (AMC)-resistant Escherichia coli were studied. OXA-1- and inhibitor-resistant TEM (IRT)-producing strains were associated with urinary tract infections, while OXA-1 producers and chromosomal AmpC hyperproducers were associated with bacteremic infections. AMC resistance in E. coli is a complex phenomenon with heterogeneous clinical implications.

Production of caffeoylmalic acid from glucose in engineered Escherichia coli.

PubMed

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.

Resistance of various shiga toxin-producing Escherichia coli to electrolyzed oxidizing water

USDA-ARS?s Scientific Manuscript database

The resistance of thirty two strains of Escherichia coli O157:H7 and six major serotypes of non-O157 Shiga toxin- producing E. coli (STEC) plus E. coli O104 was tested against Electrolyzed oxidizing (EO) water using two different methods; modified AOAC 955.16 sequential inoculation method and minim...

Esculin hydrolysis reaction by Escherichia coli.

PubMed

Miskin, A; Edberg, S C

1978-03-01

The literature contains variable reports concerning the hydrolysis of esculin by members of the family Enterobacteriaceae and particularly Escherichia coli. We examined 113 strains of fresh clinical isolates of E. coli and assessed the ability of colonies in a population to hydrolyze esculin with and without preincubation in inducible substrates at 24, 48, and 72 h. The number of strains capable of fermenting salicin, a sugar with a beta-glucoside linkage like esculin, was studied under the same conditions. A strip test that measured the presence of the constitutive glucosidase was also performed with and without preincubation in inducible substrates. No E. coli strain was able to produce constitutive enzyme; preincubation in esculin and salicin resulted in an induction of the beta-glucosidase. The number of colonies able to hydrolyze esculin increased with time. Only those strains preincubated in esculin or salicin were able to produce a positive constitutive strip test. Because the beta-glucosidase of E. coli is inducible, one should employe, when using growth media, a light inoculum obtained by touching the top of a colony with a bacteriological wire and read the reaction between 18 and 24 h, or perform a rapid strip or spot test.

Clarification of the recovery mechanism of Escherichia coli after hydrostatic pressure treatment

NASA Astrophysics Data System (ADS)

Ohshima, Shuto; Nomura, Kazuki; Iwahashi, Hitoshi

2013-06-01

High hydrostatic pressure (HP) technology has gained more attention as a non-thermal food pasteurization technology. Recently, a limitation of the HP technology was reported by Koseki and Yamamoto [Recovery of Escherichia coli ATCC 25922 in phosphate buffered saline after treatment with high hydrostatic pressure. Int. J. Food Microbiol. 2006;110:108-111], who completely recovered Escherichia coli species after HP treatment. We investigated the recovery mechanism of E. coli after HP treatment. The cells were treated with 200-300 MPa at 0-25°C for 24 h. The HP-treated E. coli was recovered in phosphate-buffered saline (PBS) during 120 h of incubation at 25°C, confirming the results reported by them. However, E. coli did not grow in PBS but grew with inactivated cells in PBS. In addition, the results of our "population size experiments" demonstrated that the recovery of E. coli cells depended on both the degree of pressure and the population size. These results suggest that some portion of cells recovered from the damage and then grew by using inactivated cells.

tir- and stx- positive Escherichia coli in stream waters in a metropolitan area

Treesearch

James A. Higgins; Kenneth T. Belt; Jeffrey S. Karns; Jonathan Russell-Anelli; Daniel R. Shelton

2005-01-01

Diarrheagenic Escherichia coli, which may include the enteropathogenic E. coli and the enterohemorrhagic E. coli, are a significant cause of diarrheal disease among infants and children in both developing and developed areas. Disease outbreaks related to freshwater exposure have been documented, but the presence...

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

PubMed Central

Dimitrova, Daniela; Engelbrecht, Kathleen C.; 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. PMID:28684574

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

PubMed

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.

A critical examination of Escherichia coli esterase activity.

PubMed

Antonczak, Alicja K; Simova, Zuzana; Tippmann, Eric M

2009-10-16

The ability of Escherichia coli to grow on a series of acetylated and glycosylated compounds has been investigated. It is surmised that E. coli maintains low levels of nonspecific esterase activity. This observation may have ramifications for previous reports that relied on nonspecific esterases from E. coli to genetically encode nonnatural amino acids. It had been reported that nonspecific esterases from E. coli deacetylate tri-acetyl O-linked glycosylated serine and threonine in vivo. The glycosylated amino acids were reported to have been genetically encoded into proteins in response to the amber stop codon. However, it is our contention that such amino acids are not utilized in this manner within E. coli. The current results report in vitro analysis of the original enzyme and an in vivo analysis of a glycosylated amino acid. It is concluded that the amber suppression method with nonnatural amino acids may require a caveat for use in certain instances.

A Critical Examination of Escherichia coli Esterase Activity*

PubMed Central

Antonczak, Alicja K.; Simova, Zuzana; Tippmann, Eric M.

2009-01-01

The ability of Escherichia coli to grow on a series of acetylated and glycosylated compounds has been investigated. It is surmised that E. coli maintains low levels of nonspecific esterase activity. This observation may have ramifications for previous reports that relied on nonspecific esterases from E. coli to genetically encode nonnatural amino acids. It had been reported that nonspecific esterases from E. coli deacetylate tri-acetyl O-linked glycosylated serine and threonine in vivo. The glycosylated amino acids were reported to have been genetically encoded into proteins in response to the amber stop codon. However, it is our contention that such amino acids are not utilized in this manner within E. coli. The current results report in vitro analysis of the original enzyme and an in vivo analysis of a glycosylated amino acid. It is concluded that the amber suppression method with nonnatural amino acids may require a caveat for use in certain instances. PMID:19666472

Pulsed-Plasma Disinfection of Water Containing Escherichia coli

NASA Astrophysics Data System (ADS)

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.

Kinetics of Bacteriophage λ Deoxyribonucleic Acid Infection of Escherichia coli

PubMed Central

Barnhart, Benjamin J.

1965-01-01

Barnhart, Benjamin J. (Los Alamos Scientific Laboratory, University of California, Los Alamos, N.M.). Kinetics of bacteriophage λ deoxyribonucleic acid infection of Escherichia coli. J. Bacteriol. 90:1617–1623. 1965.—The kinetics of Escherichia coli K-12 infection by phage λ deoxyribonucleic acid (DNA) were determined. An initial lag of 55 to 80 sec was found to be the time required for infecting DNA to become deoxyribonuclease-insensitive at 33 C. When cell-DNA interactions were stopped by washing away unbound DNA, the already bound DNA continued to infect the cell at rates described by linear kinetics with no apparent lag. Whereas the lag period was relatively insensitive to DNA and cell concentrations, both the lag and the subsequent linear portions of the rate curves were temperature-sensitive. Cell and DNA dose-response curves prescribed hyperbolic functions. Similarities between λ DNA infection of E. coli and bacterial transformation systems are discussed. PMID:5322721

Interaction between Escherichia coli and lunar fines

NASA Technical Reports Server (NTRS)

Johansson, K. R.

1983-01-01

A sample of mature lunar fines (10084.151) was solubilized to a high degree (about 17 percent) by the chelating agent salicylic acid (0.01. M). The neutralized (pH adjusted to 7.0) leachate was found to inhibit the growth of Escherichia coli (ATCC 259922) in a minimial mineral salts glucose medium; however, the inhibition was somewhat less than that caused by neutralized salicylic acid alone. The presence of lunar fines in the minimal medium was highly stimulatory to growth of E. coli following an early inhibitory response. The bacterium survived less well in the lunar leachate than in distilled water, no doubt because of the salicylate. It was concluded that the sample of lunar soil tested has nutritional value to E. coli and that certain products of fermentation helped to solubilize the lunar soil.

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

PubMed

Wang, Shun; Xie, Jiufeng; Jiang, Min; Chang, Keke; Chen, Ruipeng; Ma, Liuzheng; Zhu, Juanhua; Guo, Qingqian; Sun, Haifeng; Hu, Jiandong

2016-11-04

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.

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

PubMed Central

Wang, Shun; Xie, Jiufeng; Jiang, Min; Chang, Keke; Chen, Ruipeng; Ma, Liuzheng; Zhu, Juanhua; Guo, Qingqian; Sun, Haifeng; Hu, Jiandong

2016-01-01

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. PMID:27827923

77 FR 9888 - Shiga Toxin-Producing Escherichia coli

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-21

... Toxin-Producing Escherichia coli in Certain Raw Beef Products AGENCY: Food Safety and Inspection Service... routine verification sampling and testing for raw beef manufacturing trimmings for six non-O157 Shiga... announced in September 2011 plans to test certain raw beef products for these six STEC serogroups in...

Catabolite Repression of Escherichia coli Biofilm Formation

PubMed Central

Jackson, Debra W.; Simecka, Jerry W.; Romeo, Tony

2002-01-01

Biofilm formation was repressed by glucose in several species of Enterobacteriaceae. In Escherichia coli, this effect was mediated at least in part by cyclic AMP (cAMP)-cAMP receptor protein. A temporal role for cAMP in biofilm development was indicated by the finding that glucose addition after ∼24 h failed to repress and generally activated biofilm formation. PMID:12029060

Removing Escherichia coli from water using zinc oxide-coated zeolite.

PubMed

Wang, Lingling; Wu, Wenlin; Xie, Xiaolan; Chen, Hongbin; Lin, Jianming; Dionysiou, Dionysios D

2018-05-11

The removal of Escherichia coli (E. coli) from water by zinc oxide-coated zeolite (ZOCZ) and ZOCZ's antibacterial properties were examined in laboratory experiments using plate counting method and tests of cell apoptosis. Batch experiments showed that ZOCZ has a maximum removal capacity for E. coli of about 4.34 × 10 6  CFU g -1  at 25 °C. Element mappings confirm that zinc ions accumulate in the E. coli cells causing cell death. Pseudo-second-order kinetics and Freundlich isotherms were found to best describe the removal of E. coli, suggesting that a multilayer of E. coli cells forms on the surface of ZOCZ particles. Copyright © 2018 Elsevier Ltd. All rights reserved.

Predictors of asymptomatic bacteriuria among pregnant women in a low-resource setting.

PubMed

Awoleke, J O; Adanikin, A I; Ajayi, D D; Ayosanmi, O S

2015-01-01

This study aims at identifying predictors of asymptomatic bacteriuria (AB) among pregnant women in a low-resource setting, with the intent of recommending a guideline for screening during antenatal care. A total of 266 healthy pregnant women were antenatally recruited after informed consent. They had routine antenatal investigations, a 1 h 50-g oral glucose tolerance test and quantitative urine culture and sensitivity. The data collected were analysed using statistical software package SPSS v. 17. Prevalence of AB was 23 (8.6%). Escherichia coli was the commonest isolate (6, 26.1%), closely followed by Staphylococcus aureus (5, 21.7%). AB was commoner among patients aged 25-34 years, of low parity and higher education. Blood group B- rhesus-positive significantly predicts the likelihood of developing AB in pregnancy (adjusted OR: 0.36; 95% CI: 0.14-0.96). We conclude that blood group B-rhesus-positive in association with other patients' characteristics, such as age 25-34 years, low parity and higher education could form guidelines for a screening algorithm in our environment.

Adhesion, biofilm and genotypic characteristics of antimicrobial resistant Escherichia coli isolates.

PubMed

Cergole-Novella, Maria C; Pignatari, Antonio C C; Guth, Beatriz E C

2015-03-01

Aggregative adherence to human epithelial cells, most to renal proximal tubular (HK-2) cells, and biofilm formation was identified among antimicrobial resistant Escherichia coli strains mainly isolated from bacteremia. The importance of these virulence properties contributing to host colonization and infection associated with multiresistant E. coli should not be neglected.

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

PubMed Central

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

TRIMETHOPRIM-SULFAMETHOXAZOLE RESISTANCE IN SEWAGE ISOLATES OF ESCHERICHIA COLI

EPA Science Inventory

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...

Mouse in vivo neutralization of Escherichia coli Shiga toxin 2 with monoclonal antibodies

USDA-ARS?s Scientific Manuscript database

Escherichia coli (E. coli) food contaminations pose serious health and food safety concerns, and have been the subject of massive food recalls. Shiga toxin 2 (Stx2)-producing E. coli has been identified as the major cause of hemorrhagic colitis and hemolytic uremic syndrome (HUS), the most severe di...

Release of Escherichia coli under raindrop impact: The role of clay

NASA Astrophysics Data System (ADS)

Wang, C.; Parlange, J.-Y.; Schneider, R. L.; Rasmussen, E. W.; Wang, X.; Chen, M.; Dahlke, H. E.; Truhlar, A. M.; Walter, M. T.

2018-01-01

A recent paper by Wang et al. (2017) showed that the release of Escherichia coli (E. coli) from soil into overland flow under raindrop impact and the release of clay follow identical temporal patterns. This raised the question: what is the role of clay, if any, in E. coli transfer from soil to overland flow, e.g., does clay facilitate E. coli transfer? Using simulated rainfall experiments over soil columns with and without clay in the matrix, we found there was significantly more E. coli released from the non-clay soil because raindrops penetrated more deeply than into the soil with clay.

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

PubMed

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.

TRIMETHOPRIM-SULFAMETHOXAZOLE RESISTANCE IN SEWAGE ISOLATES OF ESCHERICHIA COLI

EPA Science Inventory

The increase in resistance rates to trimehtoprim-sulfamethoxazole (TMP/SMX) in isolates of Escherichia coli has become a matter of increasing concern. This has been particularly true in reference to community acquired urinary tract infections (UTI). This study utilized sewage i...

ANIMAL ENTEROTOXIGENIC ESCHERICHIA COLI

PubMed Central

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

The Biology of the Escherichia coli Extracellular Matrix

PubMed Central

Hufnagel, David A.; DePas, William H.; Chapman, Matthew R.

2015-01-01

Chapter Summary Escherichia coli (E. coli) is one of the world’s best-characterized organisms, as it has been extensively studied for over a century. However, most of this work has focused on E. coli grown under laboratory conditions that do not faithfully simulate its natural environments. Therefore, the historical perspectives on E. coli physiology and life cycle are somewhat skewed toward experimental systems that feature E. coli growing logarithmically in a test tube. Typically a commensal bacterium, E. coli resides in the lower intestines of a slew of animals. Outside of the lower intestine, E. coli can adapt and survive in a very different set of environmental conditions. Biofilm formation allows E. coli to survive, and even thrive, in environments that do not support the growth of planktonic populations. E. coli can form biofilms virtually everywhere; in the bladder during a urinary tract infection, on in-dwelling medical devices, and outside of the host on plants and in the soil. The E. coli extracellular matrix, primarily composed of the protein polymer named curli and the polysaccharide cellulose, promotes adherence to organic and inorganic surfaces, and resistance to desiccation, the host immune system and other antimicrobials. The pathways that govern E. coli biofilm formation, cellulose production, and curli biogenesis will be discussed in this book chapter, which concludes with insights into the future of E. coli biofilm research and potential therapies. PMID:26185090

Asymtomatic bacteriuria in pregnancy: assesment of prevlence, microbial agents and ther antimicrobial sensitivty pattern in Gondar Teaching Hospital, north west Ethiopia.

PubMed

Tadesse, Abilo; Negash, Mekonnen; Ketema, Late Shimeles

2007-04-01

To estimate the prevalence of asymptomatic bacteriuria in pregnant women, identify the frequently isolated uropathogenic bacteria and its antimicrobial sensitivity pattern. This cross-sectional case series study was conducted in antenatal care clinic of Gondar Teaching Hospital from June-Oct., 2001. One hundred and seventy three pregnant women, who met the inclusion criteria, were included in the study after informed consent was obtained Clinical information pertaining to socio demographic data and obstetric history was filled in the questionnaire, pertinent physical examination was done and urine specimen from each candidate was collected and processed following the standard microbiological technique. Majority (70-90%) of the pregnant women were literate, housewives, married and residents of Gondar town. Of all pregnant women included in the study, 96/173 (56%) were multigravida, and 21/173 (12%) had 5 or more pregnancies. The identification rate of significant bacteriuria in the study group was 9.8% (17/173) with higher rate (20.5%) in multiparous mothers. The frequently isolated urinary pathogenic bacteria was E. coli, 47% (8/17), followed by S. aureus 3/17 (18%) and C. freundi 2/17 (12%). The majority of E. coli isolates (50-75%) were resistant to gentamicin, Ampicillin, trimethoprim-sulphamethoxazole, tetracycline, and chloramphenicol; while 75% and 100% of E. coli isolates were sensitive to cefoxitin, and ciprofloxacin respectively. Asymptomatic bacteriuria in pregnant women was prevalent in the study locality. E. coli was the common isolated urinary pathogen among urine samples of study subjects, and was found to be resistant to multiple antimicrobial agents. We suggest cefoxitin should be the drug used to treat significant bacteriuria in pregnant women in the study locality.

Inflammatory response to Escherichia coli urinary tract infection in the neurogenic bladder of the spinal cord injured host.

PubMed

Chaudhry, Rajeev; Madden-Fuentes, Ramiro J; Ortiz, Tara K; Balsara, Zarine; Tang, Yuping; Nseyo, Unwanaobong; Wiener, John S; Ross, Sherry S; Seed, Patrick C

2014-05-01

Urinary tract infections cause significant morbidity in patients with spinal cord injury. An in vivo spinal cord injured rat model of experimental Escherichia coli urinary tract infection mimics human disease with enhanced susceptibility to urinary tract infection compared to controls. We hypothesized that a dysregulated inflammatory response contributes to enhanced susceptibility to urinary tract infection. Spinal cord injured and sham injured rats were inoculated transurethrally with E. coli. Transcript levels of 84 inflammatory pathway genes were measured in bladder tissue of each group before infection, 24 hours after infection and after 5 days of antibiotic therapy. Before infection quantitative polymerase chain reaction array revealed greater than twofold up-regulation in the proinflammatory factor transcripts slc11a1, ccl4 and il1β, and down-regulation of the antimicrobial peptides lcn2 and mpo in spinal cord injured vs control bladders. At 24 hours after infection spinal cord injured bladders showed an attenuated innate immune response with decreased expression of il6, slc11a1, il1β and lcn2, and decreased il10 and slpi expression compared to controls. Despite clearance of bacteriuria with antibiotics spinal cord injured rats had delayed induction of il6 transcription and a delayed anti-inflammatory response with decreased il10 and slpi transcript levels relative to controls. Spinal cord injured bladders fail to mount a characteristic inflammatory response to E. coli infection and cannot suppress inflammation after infection is eliminated. This may lead to increased susceptibility to urinary tract infection and persistent chronic inflammation through neural mediated pathways, which to our knowledge remain to be defined. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Esculin hydrolysis reaction by Escherichia coli.

PubMed Central

Miskin, A; Edberg, S C

1978-01-01

The literature contains variable reports concerning the hydrolysis of esculin by members of the family Enterobacteriaceae and particularly Escherichia coli. We examined 113 strains of fresh clinical isolates of E. coli and assessed the ability of colonies in a population to hydrolyze esculin with and without preincubation in inducible substrates at 24, 48, and 72 h. The number of strains capable of fermenting salicin, a sugar with a beta-glucoside linkage like esculin, was studied under the same conditions. A strip test that measured the presence of the constitutive glucosidase was also performed with and without preincubation in inducible substrates. No E. coli strain was able to produce constitutive enzyme; preincubation in esculin and salicin resulted in an induction of the beta-glucosidase. The number of colonies able to hydrolyze esculin increased with time. Only those strains preincubated in esculin or salicin were able to produce a positive constitutive strip test. Because the beta-glucosidase of E. coli is inducible, one should employe, when using growth media, a light inoculum obtained by touching the top of a colony with a bacteriological wire and read the reaction between 18 and 24 h, or perform a rapid strip or spot test. PMID:418079

Variations of Escherichia coli O157:H7 Survival in Purple Soils

PubMed Central

Zhang, Taoxiang; Hu, Suping; Yang, Wenhao

2017-01-01

Escherichia coli O157:H7 is a well-recognized cause of human illness. Survival of Escherichia coli O157:H7 in five purple soils from Sichuan Province was investigated. The dynamics of E. coli O157:H7 survival in purple soils were described by the Weibull model. Results showed that this model is suitable to fit survival curves of E. coli O157:H7 in purple soils, with the calculated td value (survival time needed to reach the detection limit of 100 CFU·g−1) ranging from 2.99 days to 26.36 days. The longest survival time of E. coli O157:H7 was observed in neutral purple soils (24.49 days), followed by alkalescent purple soil (18.62 days) and acid purple soil (3.48 days). The redundancy analysis (RDA) revealed that td values were significantly enhanced by soil nutrition (total organic carbon (OC), total nitrogen (TN), available potassium (AK) and the ratio of humic acid to fulvic acid (Ha/Fa)), but were significantly suppressed by iron and aluminum oxide. PMID:29057845

Inactivation of Escherichia coli by titanium dioxide photocatalytic oxidation.

EPA Science Inventory

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...

DETECTION OF ESCHERICHIA COLI IN WATER USING A COLORIMETRIC GENE PROBE ASSAY

EPA Science Inventory

A commercially available DNA hydribization assay (Gene-trak , Framingham, MA. USA) was compared with the EC-MUG procedure for the detection of Escherichia coli in water. The gene probe gave positive responses for pure cultures of E. coli 0157:H7, E. fergusonii, Shigella sonnei, S...

ESCHERICHIA COLI AND TOTAL COLIFORMS IN WATER AND SEDIMENTS AT LAKE MARINAS

EPA Science Inventory

Escherichia coli, a fecal coliform, and total coliforms were monitored between September 1999 to October 2001 in five marinas on Lake Texoma, located on the Oklahoma and Texas border. General trend was that densities of E. coli were lower in the summer season due to the lower ...

Urinary Tract Infection and Bacteriuria in Pregnancy.

PubMed

Glaser, Alexander P; Schaeffer, Anthony J

2015-11-01

Bacteriuria during pregnancy may be classified as asymptomatic bacteriuria, infections of the lower urinary tract (cystitis), or infections of the upper urinary tract (pyelonephritis). Lower tract bacteriuria is associated with an increased risk of developing pyelonephritis in pregnancy, which is itself associated with adverse maternal and fetal outcomes. Pregnant women should be screened for the presence of bacteriuria early in pregnancy. All bacteriuria in pregnancy should be treated, and antimicrobial choice in pregnancy should reflect safety for both the mother and the fetus. After treatment of bacteriuria, patients should be followed closely due to risk of recurrent bacteriuria. Copyright © 2015 Elsevier Inc. All rights reserved.

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

PubMed

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.

Antimicrobial and disinfectant resistance of Escherichia coli isolated from giant pandas.

PubMed

Guo, L; Long, M; Huang, Y; Wu, G; Deng, W; Yang, X; Li, B; Meng, Y; Cheng, L; Fan, L; Zhang, H; Zou, L

2015-07-01

The study aims to demonstrate the antimicrobial and disinfectant resistance phenotypes and genotypes of Escherichia coli isolates obtained from giant pandas (Ailuropoda melanoleuca). Antimicrobial testing was performed according to the standard disk diffusion method. The minimal inhibitory concentrations (MICs) of disinfectants were determined using the agar dilution method. All isolates were screened for the presence of antimicrobial and disinfectant resistance genes and further analysed for genetic relatedness by pulse-field gel electrophoresis (PFGE). Results showed that 46·6% of the isolates were resistant to at least one antimicrobial. Escherichia coli isolates showed resistance to fewer antimicrobials as panda age increased. Among antimicrobial-resistant E. coli isolates, the antimicrobial resistance genes blaCTX-M (88·2%) and sul1 (92·3%) were most prevalent. The disinfectant resistance genes emrE, ydgE/ydgF, mdfA and sugE(c) were commonly present (68·2-98·9%), whereas qac and sugE(p) were relatively less prevalent (0-21·3%). The frequencies of resistance genes tended to be higher in E. coli isolated in December than in July, and PFGE profiles were also more diverse in isolates in December. The qacEΔ1 and sugE(p) genes were higher in adolescent pandas than in any other age groups. PFGE revealed that antimicrobial resistance correlated well with sampling time and habitat. This study demonstrated that antimicrobial and disinfectant resistance was common in giant panda-derived E. coli, and the antimicrobial resistance was associated with sampling time and habitat. Escherichia coli could serve as a critical vector in spreading disinfectant and antimicrobial resistance. This is the first study that demonstrated the phenotypic and genetic characterizations of antimicrobial and disinfectant resistance in E. coli isolates from more than 60 giant pandas. Frequent transfer of pandas to other cages may lead to the dissemination of antimicrobial resistance. The

Comparative genomics of enterohemorrhagic Escherichia coli O145:H28 demonstrates a common evolutionary lineage with Escherichia coli O157:H7

USDA-ARS?s Scientific Manuscript database

Background Although serotype O157:H7 is the predominant enterohemorrhagic Escherichia coli (EHEC), outbreaks of non-O157 EHEC that cause severe foodborne illness, including hemolytic uremic syndrome have increased worldwide. In fact, non-O157 serotypes are now estimated to cause over half of all the...

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

USDA-ARS?s Scientific Manuscript database

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...

Exogenous carbon monoxide suppresses Escherichia coli vitality and improves survival in an Escherichia coli-induced murine sepsis model.

PubMed

Shen, Wei-chang; Wang, Xu; Qin, Wei-ting; Qiu, Xue-feng; Sun, Bing-wei

2014-12-01

Endogenous carbon monoxide (CO) has been shown to modulate inflammation and inhibit cytokine production both in vivo and in vitro. The aim of this study was to examine whether exogenous carbon monoxide could suppress the vitality of Escherichia coli (E coli) and improve the survival rate in an E coli-induced murine sepsis model. ICR mice were infected with E coli, and immediately injected intravenously with carbon monoxide releasing molecule-2 (CORM-2, 8 mg/kg) or inactive CORM-2 (8 mg/kg). The survival rate was monitored 6 times daily for up to 36 h. The blood samples, liver and lung tissues were collected at 6 h after the infection. Bacteria in peritoneal lavage fluid, blood and tissues were enumerated following culture. Tissue iNOS mRNA expression was detected using RT-PCR. NF-κB expression was detected with Western blotting. Addition of CORM-2 (200 and 400 μmol/L) into culture medium concentration-dependently suppressed the growth of E coli and decreased the colony numbers, but inactive CORM-2 had no effect. Treatment of the infected mice with CORM-2 significantly increased the survival rate to 55%, while all the infected mice treated with inactive CORM-2 died within 36 h. E coli infection caused severe pathological changes in liver and lungs, and significantly increased serum transaminases, lipopolysaccharide, TNF-α and IL-1β levels, as well as myeloperoxidase activity, TNF-α and IL-1β levels in the major organs. Meanwhile, E coli infection significantly increased the number of colonies and the expression of iNOS mRNA and NF-κB in the major organs. All these abnormalities were significantly attenuated by CORM-2 treatment, while inactive CORM-2 was ineffective. In addition directly suppressing E coli, CORM-2 protects the liver and lungs against E coli-induced sepsis in mice, thus improving their survival.

Current pathogenic Escherichia coli foodborne outbreak cases and therapy development.

PubMed

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.

Formate and its role in hydrogen production in Escherichia coli.

PubMed

Sawers, R G

2005-02-01

The production of dihydrogen by Escherichia coli and other members of the Enterobacteriaceae is one of the classic features of mixed-acid fermentation. Synthesis of the multicomponent, membrane-associated FHL (formate hydrogenlyase) enzyme complex, which disproportionates formate into CO(2) and H(2), has an absolute requirement for formate. Formate, therefore, represents a signature molecule in the fermenting E. coli cell and factors that determine formate metabolism control FHL synthesis and consequently dihydrogen evolution.

Survival of Escherichia coli in common garden mulches spiked with synthetic greywater.

PubMed

Boyte, S; Quaife, S; Horswell, J; Siggins, A

2017-05-01

Reuse of domestic wastewater is increasingly practiced as a means to address global demands on fresh water. Greywater is primarily reused via subsurface irrigation of gardens, where the soil environment is seen to be an integral part of the treatment process. The fate of biological contaminants (i.e. pathogens) in the soil is reasonably well understood, but their persistence and survival in soil cover layers is largely unexplored. This study investigated the ability of Escherichia coli to survive in common soil cover layers. Three garden mulches were investigated: pea straw mulch, a bark-based mulch and a coconut husk mulch. Each mulch was treated with an E. coli solution, a synthetic greywater with E. coli, or a freshwater control. Escherichia coli was applied at 1 × 10 4  most probable number (MPN) per g dry weight mulch. Subsamples were temporally analysed for E. coli. The bark and coconut husk mulches showed a steady decline in E. coli numbers, while E. coli increased in the pea straw mulch for the duration of the 50 days experiment, peaking at 1·8 × 10 8  MPN per g dry weight mulch. This study highlighted the importance of selection of a suitable material for covering areas that are subsurface irrigated with greywater. Potential for microbial contamination is one of the limiting factors for domestic greywater reuse. Although subsurface irrigation is considered to be one of the lowest risk applications, there is still a possibility of microbes reaching the soil surface if the environmental conditions are not favourable or if soil movement inadvertently exposes the irrigation line. In these circumstances, the soil cover layer may be contaminated by greywater microbes. This study assesses the survival rates of the pathogen indicator organism Escherichia coli in three soil cover materials commonly used worldwide and makes clear recommendations to facilitate the safe reuse of domestic greywater. © 2017 The Society for Applied Microbiology.

Sex and virulence in Escherichia coli: an evolutionary perspective

PubMed Central

Wirth, Thierry; Falush, Daniel; Lan, Ruiting; Colles, Frances; Mensa, Patience; Wieler, Lothar H; Karch, Helge; Reeves, Peter R; Maiden, Martin CJ; Ochman, Howard; Achtman, Mark

2006-01-01

Pathogenic Escherichia coli cause over 160 million cases of dysentery and one million deaths per year, whereas non-pathogenic E. coli constitute part of the normal intestinal flora of healthy mammals and birds. The evolutionary pathways underlying this dichotomy in bacterial lifestyle were investigated by multilocus sequence typing of a global collection of isolates. Specific pathogen types [enterohaemorrhagic E. coli, enteropathogenic E. coli, enteroinvasive E. coli, K1 and Shigella] have arisen independently and repeatedly in several lineages, whereas other lineages contain only few pathogens. Rates of evolution have accelerated in pathogenic lineages, culminating in highly virulent organisms whose genomic contents are altered frequently by increased rates of homologous recombination; thus, the evolution of virulence is linked to bacterial sex. This long-term pattern of evolution was observed in genes distributed throughout the genome, and thereby is the likely result of episodic selection for strains that can escape the host immune response. PMID:16689791

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

USDA-ARS?s Scientific Manuscript database

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 ...

Evolution of the iss gene in Escherichia coli.

PubMed

Johnson, Timothy J; Wannemuehler, Yvonne M; Nolan, Lisa K

2008-04-01

The increased serum survival gene iss has long been recognized for its role in extraintestinal pathogenic Escherichia coli (ExPEC) virulence. iss has been identified as a distinguishing trait of avian ExPEC but not of human ExPEC. This gene has been localized to large virulence plasmids and shares strong similarities with the bor gene from bacteriophage lambda. Here, we demonstrate that three alleles of iss occur among E. coli isolates that appear to have evolved from a common lambda bor precursor. In addition to the occurrence of iss on the ColV/BM virulence plasmids, at least two iss alleles occur within the E. coli chromosome. One of these alleles (designated type 3) was found to occur in the genomes of all currently sequenced ExPEC strains on a similar prophage element that also harbors the Sit iron and manganese transport system. When the prevalence of the three iss types was examined among 487 E. coli isolates, the iss type 3 gene was found to occur at a high frequency among ExPEC isolates, irrespective of the host source. The plasmid-borne iss allele (designated type 1) was highly prevalent among avian pathogenic E. coli and neonatal meningitis-associated E. coli isolates but not among uropathogenic E. coli isolates. This study demonstrates the evolution of iss in E. coli and provides an additional tool for discriminating among E. coli pathotypes through the differentiation of the three iss allele types and bor.

Multiple Antimicrobial Resistance of Escherichia coli Isolated from Chickens in Iran

PubMed Central

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. PMID:25548716

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

PubMed

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.

Sedimentation and gravitational instability of Escherichia coli Suspension

NASA Astrophysics Data System (ADS)

Douarche, Carine; Salin, Dominique; Collaboration between Laboratory FAST; LPS Collaboration

2016-11-01

The successive run and tumble of Escherichia coli bacteria provides an active matter suspension of rod-like particles with a large swimming diffusion. As opposed to inactive elongated particles, this diffusion prevents clustering and instability in the gravity field. We measure the time dependent E . coli concentration profile during their sedimentation. After some hours, due to the dioxygen consumption, a motile / non-motile front forms leading to a Rayleigh-Taylor type gravitational instability. Analyzing both sedimentation and instability in the framework of active particle suspensions, we can measure the relevant bacteria hydrodynamic characteristics such as its single particle sedimentation velocity and its hindrance volume.

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

PubMed

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.

Fluoroquinolone-resistant Escherichia coli Carriage in Long-Term Care Facility

PubMed Central

Lee, Betsy; Lautenbach, Ebbing

2005-01-01

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. PMID:15963284

Proteomic differences between Escherichia coli strains that cause transient versus persistent intramammary infections [abstract

USDA-ARS?s Scientific Manuscript database

Escherichia coli is a leading cause of bacterial mastitis in dairy cattle. Typically this infection is transient in nature and lasts 2-3 days. However, in a minority of cases, E. coli can cause a persistent intramammary infection. The mechanisms that enable certain strains of E. coli to cause a p...

Biodegradation of Aromatic Compounds by Escherichia coli

PubMed Central

Díaz, Eduardo; Ferrández, Abel; Prieto, María A.; García, José L.

2001-01-01

Although Escherichia coli has long been recognized as the best-understood living organism, little was known about its abilities to use aromatic compounds as sole carbon and energy sources. This review gives an extensive overview of the current knowledge of the catabolism of aromatic compounds by E. coli. After giving a general overview of the aromatic compounds that E. coli strains encounter and mineralize in the different habitats that they colonize, we provide an up-to-date status report on the genes and proteins involved in the catabolism of such compounds, namely, several aromatic acids (phenylacetic acid, 3- and 4-hydroxyphenylacetic acid, phenylpropionic acid, 3-hydroxyphenylpropionic acid, and 3-hydroxycinnamic acid) and amines (phenylethylamine, tyramine, and dopamine). Other enzymatic activities acting on aromatic compounds in E. coli are also reviewed and evaluated. The review also reflects the present impact of genomic research and how the analysis of the whole E. coli genome reveals novel aromatic catabolic functions. Moreover, evolutionary considerations derived from sequence comparisons between the aromatic catabolic clusters of E. coli and homologous clusters from an increasing number of bacteria are also discussed. The recent progress in the understanding of the fundamentals that govern the degradation of aromatic compounds in E. coli makes this bacterium a very useful model system to decipher biochemical, genetic, evolutionary, and ecological aspects of the catabolism of such compounds. In the last part of the review, we discuss strategies and concepts to metabolically engineer E. coli to suit specific needs for biodegradation and biotransformation of aromatics and we provide several examples based on selected studies. Finally, conclusions derived from this review may serve as a lead for future research and applications. PMID:11729263

Escherichia coli strain Nissle 1917-from bench to bedside and back: history of a special Escherichia coli strain with probiotic properties.

PubMed

Sonnenborn, Ulrich

2016-10-01

Among the gram-negative microorganisms with probiotic properties, Escherichia coli strain Nissle 1917 (briefly EcN) is probably the most intensively investigated bacterial strain today. Since nearly 100 years, the EcN strain is used as the active pharmaceutical ingredient in a licensed medicinal product that is distributed in Germany and several other countries. Over the last few decades, novel probiotic activities have been detected, which taken together are specific of this versatile E. coli strain. This review gives a short overview on the discovery and history of the EcN strain. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Microbial aetiology and sensitivity of asymptomatic bacteriuria among ante-natal mothers in Mulago hospital, Uganda.

PubMed

Andabati, G; Byamugisha, J

2010-12-01

Asymptomatic bacteriuria in pregnancy is associated with potential urinary and obstetric complications. However the prevalence aetiology and antimicrobial sensitivity patterns of asymptomatic bacteriurea among women attending ante-natal care in our Hospital is not known. To determine the prevalence and identify the aetiological agents associated with asymptomatic bacteriurea in antenatal mothers in Mulago Hospital. We also intended to determine the anti-microbial sensitivity patterns of the common uropathogen in this population We performed culture and anti-microbial sensitivity tests on urine samples from 218 consecutive ante-natal mothers in Mulago Hospital. All participants did not have any clinical symptoms attributable to urinary tract infection. Twenty nine (13.3%) of the samples had significant bacterial growth and E.coli was the commonest isolate (51.2%). There was a high level (20-62%) of anti-bacterial resistance to the commonly used antibiotics. Asymptomatic bacteriuria is common among ante-natal mothers in Mulago. E. Coli that is resistant to the most commonly used antibiotics is the commonest isolate."

Short genome report of cellulose-producing commensal Escherichia coli 1094.

PubMed

Bernal-Bayard, Joaquin; Gomez-Valero, Laura; Wessel, Aimee; Khanna, Varun; Bouchier, Christiane; Ghigo, Jean-Marc

2018-01-01

Bacterial surface colonization and biofilm formation often rely on the production of an extracellular polymeric matrix that mediates cell-cell and cell-surface contacts. In Escherichia coli and many Betaproteobacteria and Gammaproteobacteria cellulose is often the main component of the extracellular matrix. Here we report the complete genome sequence of the cellulose producing strain E. coli 1094 and compare it with five other closely related genomes within E. coli phylogenetic group A. We present a comparative analysis of the regions encoding genes responsible for cellulose biosynthesis and discuss the changes that could have led to the loss of this important adaptive advantage in several E. coli strains. Data deposition: The annotated genome sequence has been deposited at the European Nucleotide Archive under the accession number PRJEB21000.

Escherichia coli and other Enterobacteriaceae: Food poisoning and health effects

USDA-ARS?s Scientific Manuscript database

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...

Complete Genome Sequence of Enterotoxigenic Escherichia coli Siphophage Seurat

PubMed Central

Doan, Dung P.; Lessor, Lauren E.; Hernandez, Adriana C.

2015-01-01

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. PMID:25720682

Fumarate-Mediated Persistence of Escherichia coli against Antibiotics

PubMed Central

Kim, Jun-Seob; Cho, Da-Hyeong; Heo, Paul; Jung, Suk-Chae; Park, Myungseo; Oh, Eun-Joong; Sung, Jaeyun; Kim, Pan-Jun; Lee, Suk-Chan; Lee, Dae-Hee; Lee, Sarah; Lee, Choong Hwan; Shin, Dongwoo

2016-01-01

Bacterial persisters are a small fraction of quiescent cells that survive in the presence of lethal concentrations of antibiotics. They can regrow to give rise to a new population that has the same vulnerability to the antibiotics as did the parental population. Although formation of bacterial persisters in the presence of various antibiotics has been documented, the molecular mechanisms by which these persisters tolerate the antibiotics are still controversial. We found that amplification of the fumarate reductase operon (FRD) in Escherichia coli led to a higher frequency of persister formation. The persister frequency of E. coli was increased when the cells contained elevated levels of intracellular fumarate. Genetic perturbations of the electron transport chain (ETC), a metabolite supplementation assay, and even the toxin-antitoxin-related hipA7 mutation indicated that surplus fumarate markedly elevated the E. coli persister frequency. An E. coli strain lacking succinate dehydrogenase (SDH), thereby showing a lower intracellular fumarate concentration, was killed ∼1,000-fold more effectively than the wild-type strain in the stationary phase. It appears that SDH and FRD represent a paired system that gives rise to and maintains E. coli persisters by producing and utilizing fumarate, respectively. PMID:26810657

Recent Advances in Understanding Enteric Pathogenic Escherichia coli

PubMed Central

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

Phylogenetic Group Determination of Escherichia coli Isolated from Animals Samples

PubMed Central

Morcatti Coura, Fernanda; Diniz, Soraia de Araújo; Silva, Marcos Xavier; Mussi, Jamili Maria Suhet; Barbosa, Silvia Minharro; Lage, Andrey Pereira; Heinemann, Marcos Bryan

2015-01-01

This study analyzes the occurrence and distribution of phylogenetic groups of 391 strains of Escherichia coli isolated from poultry, cattle, and water buffalo. The frequency of the phylogroups was A = 19%, B1 = 57%, B2 = 2.3%, C = 4.6%, D = 2.8%, E = 11%, and F = 3.3%. Phylogroups A (P < 0.001) and F (P = 0.018) were associated with E. coli strains isolated from poultry, phylogroups B1 (P < 0.001) and E (P = 0.002) were associated with E. coli isolated from cattle, and phylogroups B2 (P = 0.003) and D (P = 0.017) were associated with E. coli isolated from water buffalo. This report demonstrated that some phylogroups are associated with the host analyzed and the results provide knowledge of the phylogenetic composition of E. coli from domestic animals. PMID:26421310

Photoinactivation of mcr-1 positive Escherichia coli

NASA Astrophysics Data System (ADS)

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.

TRYPTOPHANASE-TRYPTOPHAN SYNTHETASE SYSTEMS IN ESCHERICHIA COLI I.

PubMed Central

Freundlich, Martin; Lichstein, Herman C.

1962-01-01

Freundlich, Martin (University of Minnesota, Minneapolis) and Herman C. Lichstein. Tryptophanase-tryptophan synthetase systems in Escherichia coli. I. Effect of tryptophan and related compounds. J. Bacteriol. 84:979–987. 1962.—The effect of tryptophan and related compounds on tryptophanase and tryptophan synthetase formation in Escherichia coli was determined. Several of these compounds stimulated the formation of tryptophanase while concomitantly decreasing the production of synthetase. A number of tryptophan analogues were found to inhibit growth. The possible mode of action of these substances was examined further. 5-Hydroxytryptophan greatly inhibited the formation of synthetase and also reduced growth. Its inhibitory action on growth was attributed, at least partially, to the false feedback inhibition of anthranilic acid formation. Tryptamine was found to be a potent inhibitor of the activity of synthetase, as well as of the enzyme(s) involved in the synthesis of anthranilic acid from shikimic acid. However, growth reduction was only partially reversed by tryptophan. Indole-3-acetic acid and indole-3-propionic acid decreased growth and increased the formation of synthetase six- to eightfold. The action of these compounds was ascribed to their ability to block the endogenous formation of tryptophan. PMID:13959621

Genomic Comparative Study of Bovine Mastitis Escherichia coli.

PubMed

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.

Genomic Comparative Study of Bovine Mastitis Escherichia coli

PubMed Central

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. PMID:26809117

Natural Escherichia coli strains undergo cell-to-cell plasmid transformation.

PubMed

Matsumoto, Akiko; Sekoguchi, Ayuka; Imai, Junko; Kondo, Kumiko; Shibata, Yuka; Maeda, Sumio

2016-12-02

Horizontal gene transfer is a strong tool that allows bacteria to adapt to various environments. Although three conventional mechanisms of horizontal gene transfer (transformation, transduction, and conjugation) are well known, new variations of these mechanisms have also been observed. We recently reported that DNase-sensitive cell-to-cell transfer of nonconjugative plasmids occurs between laboratory strains of Escherichia coli in co-culture. We termed this phenomenon "cell-to-cell transformation." In this report, we found that several combinations of Escherichia coli collection of reference (ECOR) strains, which were co-cultured in liquid media, resulted in DNase-sensitive cell-to-cell transfer of antibiotic resistance genes. Plasmid isolation of these new transformants demonstrated cell-to-cell plasmid transfer between the ECOR strains. Natural transformation experiments, using a combination of purified plasmid DNA and the same ECOR strains, revealed that cell-to-cell transformation occurs much more frequently than natural transformation under the same culture conditions. Thus, cell-to-cell transformation is both unique and effective. In conclusion, this study is the first to demonstrate cell-to-cell plasmid transformation in natural E. coli strains. Copyright © 2016 Elsevier Inc. All rights reserved.

Finished Genome Sequence of Escherichia coli K-12 Strain HMS174 (ATCC 47011).

PubMed

Mairhofer, Juergen; Krempl, Peter M; Thallinger, Gerhard G; Striedner, Gerald

2014-11-20

Escherichia coli strain K-12 substrain HMS174 is an engineered descendant of the E. coli K-12 wild-type strain. Like its ancestor, it is an important organism in biotechnological research and is used in fermentation processes for heterologous protein production. Here, we report the complete genome sequence of E. coli HMS174 (ATCC 47011). Copyright © 2014 Mairhofer et al.

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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...

Characterization of Escherichia coli 0157:H7 strains isolated from supershedding cattle

USDA-ARS?s Scientific Manuscript database

Previous reports have indicated that a small proportion of cattle shedding high levels of Escherichia coli O157:H7 is the main source for transmission of this organism between animals. Cattle achieving a fecal shedding status of 10**4 CFU of E. coli O157: H7/gram or greater are now referred to as su...

Escherichia coli type III secretion system 2: a new kind of T3SS?

PubMed

Zhou, Mingxu; Guo, Zhiyan; Duan, Qiangde; Hardwidge, Philip R; Zhu, Guoqiang

2014-03-19

Type III secretion systems (T3SSs) are employed by Gram-negative bacteria to deliver effector proteins into the cytoplasm of infected host cells. Enteropathogenic Escherichia coli use a T3SS to deliver effector proteins that result in the creation of the attaching and effacing lesions. The genome sequence of the Escherichia coli pathotype O157:H7 revealed the existence of a gene cluster encoding components of a second type III secretion system, the E. coli type III secretion system 2 (ETT2). Researchers have revealed that, although ETT2 may not be a functional secretion system in most (or all) strains, it still plays an important role in bacterial virulence. This article summarizes current knowledge regarding the E. coli ETT2, including its genetic characteristics, prevalence, function, association with virulence, and prospects for future work.

Draft Genome Sequences of Escherichia coli Isolates from Wounded Military Personnel.

PubMed

Arivett, Brock A; Ream, Dave C; Fiester, Steven E; Kidane, Destaalem; Actis, Luis A

2016-08-11

Members of the Escherichia coli bacterial family have been grouped as ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens because of their extensive drug resistance phenotypes and increasing threat to human health. The genomes of six extended-spectrum β-lactamase (ESBL)-producing E. coli strains isolated from wounded military personnel were sequenced and annotated. Copyright © 2016 Arivett et al.

Incidence of Escherichia coli in black walnut meats.

PubMed

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.

Incidence of Escherichia coli in Black Walnut Meats

PubMed Central

Meyer, Melvin T.; Vaughn, Reese H.

1969-01-01

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. PMID:4905608

Functions of the gene products of Escherichia coli.

PubMed Central

Riley, M

1993-01-01

A list of currently identified gene products of Escherichia coli is given, together with a bibliography that provides pointers to the literature on each gene product. A scheme to categorize cellular functions is used to classify the gene products of E. coli so far identified. A count shows that the numbers of genes concerned with small-molecule metabolism are on the same order as the numbers concerned with macromolecule biosynthesis and degradation. One large category is the category of tRNAs and their synthetases. Another is the category of transport elements. The categories of cell structure and cellular processes other than metabolism are smaller. Other subjects discussed are the occurrence in the E. coli genome of redundant pairs and groups of genes of identical or closely similar function, as well as variation in the degree of density of genetic information in different parts of the genome. PMID:7508076

Role of Escherichia coli in Biofuel Production

PubMed Central

Koppolu, Veerendra; Vasigala, Veneela KR

2016-01-01

Increased energy consumption coupled with depleting petroleum reserves and increased greenhouse gas emissions have renewed our interest in generating fuels from renewable energy sources via microbial fermentation. Central to this problem is the choice of microorganism that catalyzes the production of fuels at high volumetric productivity and yield from cheap and abundantly available renewable energy sources. Microorganisms that are metabolically engineered to redirect renewable carbon sources into desired fuel products are contemplated as best choices to obtain high volumetric productivity and yield. Considering the availability of vast knowledge in genomic and metabolic fronts, Escherichia coli is regarded as a primary choice for the production of biofuels. Here, we reviewed the microbial production of liquid biofuels that have the potential to be used either alone or in combination with the present-day fuels. We specifically highlighted the metabolic engineering and synthetic biology approaches used to improve the production of biofuels from E. coli over the past few years. We also discussed the challenges that still exist for the biofuel production from E. coli and their possible solutions. PMID:27441002

Metabolite profiling of foodborne disease significance – case study Escherichia coli O157

USDA-ARS?s Scientific Manuscript database

In the United States, Escherichia coli (E. coli) O157 infection, associated with the consumption of contaminated ground beef, has resulted in an unnecessary burden for both the meat industry and the health care system, with meat recalls and often fatal human disease. Cattle, the primary reservoirs f...

Avian pathogenic Escherichia coli bind fibronectin and laminin.

PubMed

Ramírez, Rosa María; Almanza, Yolanda; González, Rafael; García, Santos; Heredia, Norma

2009-04-01

Avian colisepticemia frequently occurs after respiratory tract damage, the primary site for infection allows bacteria to encounter an exposed basement membrane, where laminin and fibronectin are important components. We investigated the ability of an isolate of avian pathogenic Escherichia coli to bind fibronectin and laminin. Using Far-western dot blot analysis, we demonstrated the ability of this microorganism to bind basement membrane proteins fibronectin and laminin. Results from an ELISA-based approach indicate that the binding to these membrane proteins was bacterial-dose dependent. Furthermore, two specific E. coli polypeptides, of 32 kDa and 130 kDa, reacted with laminin and fibronectin, respectively. Further evaluation of these potential bacterial adhesins may provide insights into the pathogenesis of colibacillosis.

Recombinant protein expression in Escherichia coli: advances and challenges

PubMed Central

Rosano, Germán L.; Ceccarelli, Eduardo A.

2014-01-01

Escherichia coli is one of the organisms of choice for the production of recombinant proteins. Its use as a cell factory is well-established and it has become the most popular expression platform. For this reason, there are many molecular tools and protocols at hand for the high-level production of heterologous proteins, such as a vast catalog of expression plasmids, a great number of engineered strains and many cultivation strategies. We review the different approaches for the synthesis of recombinant proteins in E. coli and discuss recent progress in this ever-growing field. PMID:24860555

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

EPA Science Inventory

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 ...

Complete Genome Sequence of Enterotoxigenic Escherichia coli Siphophage Seurat.

PubMed

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.

Effect of phytoplankton on Escherichia coli survival in laboratory microcosms

USDA-ARS?s Scientific Manuscript database

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...

Escherichia coli as other Enterobacteriaceae: food poisoning and health effects

USDA-ARS?s Scientific Manuscript database

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...

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

PubMed

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.

Research progress of asymptomatic bacteriuria before arthroplasty

PubMed Central

Zhang, Qingyu; Liu, Lihua; Sun, Wei; Gao, Fuqiang; Cheng, Liming; Li, Zirong

2018-01-01

Abstract Background: A high prevalence of asymptomatic bacteriuria exists in patients prior to arthroplasty, and urinary tract infection is considered to be a source of postoperative superficial wound and prosthetic joint infections. There is no consensus whether to screen for and treat asymptomatic bacteriuria before arthroplasty. Objective: To summarize the association between asymptomatic bacteriuria and complications after arthroplasty and to evaluate the clinical benefits of treating asymptomatic bacteriuria prior to arthroplasty. Method: We systematically searched PubMed, Embase, and the Cochrane Library to retrieve potentially eligible articles. By screening the titles and abstracts of retrieved records and then reading the full texts of the remaining papers, we finally included 8 English-language articles in this systematic review. Results: Asymptomatic bacteriuria prior to arthroplasty is significantly associated with an increased occurrence of postoperative prosthetic joint and superficial wound infections. However, there is little evidence for direct or hematogenous seeding of urinary infections, and treating asymptomatic bacteriuria before arthroplasty did not decrease the incidence of postoperative infectious complications. Conclusion: Asymptomatic bacteriuria is not a contraindication for arthroplasty, and the practice of routine preoperative screening for and treatment of asymptomatic bacteriuria should not be continued. PMID:29443741

The Escherichia coli Proteome: Past, Present, and Future Prospects†

PubMed Central

Han, Mee-Jung; Lee, Sang Yup

2006-01-01

Proteomics has emerged as an indispensable methodology for large-scale protein analysis in functional genomics. The Escherichia coli proteome has been extensively studied and is well defined in terms of biochemical, biological, and biotechnological data. Even before the entire E. coli proteome was fully elucidated, the largest available data set had been integrated to decipher regulatory circuits and metabolic pathways, providing valuable insights into global cellular physiology and the development of metabolic and cellular engineering strategies. With the recent advent of advanced proteomic technologies, the E. coli proteome has been used for the validation of new technologies and methodologies such as sample prefractionation, protein enrichment, two-dimensional gel electrophoresis, protein detection, mass spectrometry (MS), combinatorial assays with n-dimensional chromatographies and MS, and image analysis software. These important technologies will not only provide a great amount of additional information on the E. coli proteome but also synergistically contribute to other proteomic studies. Here, we review the past development and current status of E. coli proteome research in terms of its biological, biotechnological, and methodological significance and suggest future prospects. PMID:16760308

Role of peripheral pooling in porcine Escherichia coli sepsis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teule, G.J.; von Lingen, A.; Verwey von Vught, M.A.

In anesthesized pigs the effects of E. coli (2 X 10(8)/kg) on hemodynamics and red cell distribution were studied. After injection of 99m-Tc red cells (15 mCi), regional radioactivity was followed during 3 hours. Gated bloodpool studies were performed to measure end-diastolic volumes (EDV). Escherichia coli E. coli was infused in 14 pigs, while 7 animals served as controls. E. coli resulted in an early increase in pulmonary arterial pressure. Systemic arterial pressure decreased gradually, while cardiac output did not change significantly. The gated studies revealed that especially left ventricular end-diastolic volume (LVEDV) declined, to 50% of the basal value.more » Regional radioactivity did not change over lungs, liver and abdomen. Splenic activity declined markedly. Over the hindlimb a significant increase (29 +/- 8%) was observed. It is concluded that E. coli infusion in pigs induces a hemodynamic pattern similar to human sepsis. The decrease in LVEDV is probably related to peripheral pooling and a change in right ventricle (RV) performance.« less

77 FR 31975 - Shiga Toxin-Producing Escherichia coli in Certain Raw Beef Products

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-31

...-2010-0023] Shiga Toxin-Producing Escherichia coli in Certain Raw Beef Products AGENCY: Food Safety and... testing raw beef manufacturing trimmings. SUMMARY: The Food Safety and Inspection Service (FSIS) is... (STEC), in addition to E. coli O157:H7, in raw beef manufacturing trimmings beginning June 4, 2012. FSIS...

Complete genome sequences of two atypical enteropathogenic Escherichia coli O145 environmental strains

USDA-ARS?s Scientific Manuscript database

Escherichia coli O145 strains RM14715 and RM14723 were isolated from wildlife feces near a leafy greens-growing region in Yuma, Arizona. Both strains carry a distinct genotype compared with the E. coli O145 strains isolated from Salinas Valley, California. Here we report complete genome sequences an...

Recovery of Escherichia coli from Soil after Addition of Sterile Organic Wastes

PubMed Central

Unc, Adrian; Gardner, Julie; Springthorpe, Susan

2006-01-01

Laboratory batch tests indicate that addition of sterile municipal sewage biosolids to clay soil from four depths increases the numbers of Escherichia coli isolates recoverable in EC-MUG broth (EC broth with 4-methylumbelliferyl-β-glucuronide). This effect was most marked for the deeper soil layers, with increases of about 2.6 orders of magnitude in E. coli most probable number. PMID:16517690

Genome Sequence of the Shiga Toxin-Producing Escherichia coli Strain NCCP15657

PubMed Central

Kim, Byung Kwon; Song, Geun Cheol; Hong, Gun Hyong; Seong, Won-Keun; Kim, Seon-Young; Jeong, Haeyoung; Kang, Sung Gyun; Kwon, Soon-Kyeong; Lee, Choong Hoon; Song, Ju Yeon; Yu, Dong Su; Park, Mi-Sun

2012-01-01

Shiga toxin-producing Escherichia coli causes bloody diarrhea and hemolytic-uremic syndrome and serious outbreaks worldwide. Here, we report the draft genome sequence of E. coli NCCP15657 isolated from a patient. The genome has virulence genes, many in the locus of enterocyte effacement (LEE) island, encoding a metalloprotease, the Shiga toxin, and constituents of type III secretion. PMID:22740674

Advances in molecular serotyping and subtyping of Escherichia coli

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fratamico, Pina M.; DebRoy, Chitrita; Liu, Yanhong

Escherichia coli plays an important role as a member of the gut microbiota; however, pathogenic strains also exist, including various diarrheagenic E. coli pathotypes and extraintestinal pathogenic E. coli that cause illness outside of the GI-tract. E. coli have traditionally been serotyped using antisera against the ca. 186 O-antigens and 53 H-flagellar antigens. Phenotypic methods, including bacteriophage typing and O- and H- serotyping for differentiating and characterizing E. coli have been used for many years; however, these methods are generally time consuming and not always accurate. Advances in next generation sequencing technologies have made it possible to develop genetic-based subtypingmore » and molecular serotyping methods for E. coli, which are more discriminatory compared to phenotypic typing methods. Furthermore, whole genome sequencing (WGS) of E. coli is replacing established subtyping methods such as pulsedfield gel electrophoresis, providing a major advancement in the ability to investigate food-borne disease outbreaks and for trace-back to sources. Furthermore, a variety of sequence analysis tools and bioinformatic pipelines are being developed to analyze the vast amount of data generated by WGS and to obtain specific information such as O- and H-group determination and the presence of virulence genes and other genetic markers.« less

Advances in molecular serotyping and subtyping of Escherichia coli

DOE PAGES

Fratamico, Pina M.; DebRoy, Chitrita; Liu, Yanhong; ...

2016-05-03

Escherichia coli plays an important role as a member of the gut microbiota; however, pathogenic strains also exist, including various diarrheagenic E. coli pathotypes and extraintestinal pathogenic E. coli that cause illness outside of the GI-tract. E. coli have traditionally been serotyped using antisera against the ca. 186 O-antigens and 53 H-flagellar antigens. Phenotypic methods, including bacteriophage typing and O- and H- serotyping for differentiating and characterizing E. coli have been used for many years; however, these methods are generally time consuming and not always accurate. Advances in next generation sequencing technologies have made it possible to develop genetic-based subtypingmore » and molecular serotyping methods for E. coli, which are more discriminatory compared to phenotypic typing methods. Furthermore, whole genome sequencing (WGS) of E. coli is replacing established subtyping methods such as pulsedfield gel electrophoresis, providing a major advancement in the ability to investigate food-borne disease outbreaks and for trace-back to sources. Furthermore, a variety of sequence analysis tools and bioinformatic pipelines are being developed to analyze the vast amount of data generated by WGS and to obtain specific information such as O- and H-group determination and the presence of virulence genes and other genetic markers.« less

Advances in Molecular Serotyping and Subtyping of Escherichia coli.

PubMed

Fratamico, Pina M; DebRoy, Chitrita; Liu, Yanhong; Needleman, David S; Baranzoni, Gian Marco; Feng, Peter

2016-01-01

Escherichia coli plays an important role as a member of the gut microbiota; however, pathogenic strains also exist, including various diarrheagenic E. coli pathotypes and extraintestinal pathogenic E. coli that cause illness outside of the GI-tract. E. coli have traditionally been serotyped using antisera against the ca. 186 O-antigens and 53 H-flagellar antigens. Phenotypic methods, including bacteriophage typing and O- and H- serotyping for differentiating and characterizing E. coli have been used for many years; however, these methods are generally time consuming and not always accurate. Advances in next generation sequencing technologies have made it possible to develop genetic-based subtyping and molecular serotyping methods for E. coli, which are more discriminatory compared to phenotypic typing methods. Furthermore, whole genome sequencing (WGS) of E. coli is replacing established subtyping methods such as pulsed-field gel electrophoresis, providing a major advancement in the ability to investigate food-borne disease outbreaks and for trace-back to sources. A variety of sequence analysis tools and bioinformatic pipelines are being developed to analyze the vast amount of data generated by WGS and to obtain specific information such as O- and H-group determination and the presence of virulence genes and other genetic markers.

High sensitive and selective Escherichia coli detection using immobilized optical fiber microprobe

NASA Astrophysics Data System (ADS)

Li, Yanpeng; Sun, Qizhen; Luo, Yiyang; Li, Yue; Gong, Andong; Zhang, Haibin; Liu, Deming

2017-04-01

We proposed and demonstrated a stable, label-free bacteriophage-based sensor of Escherichia coli using microfiber probe. T4 Bacteriophage was covalently immobilized on microfiber surface and E.coli concentration was investigated using the high accurate spectral interference mechanism. By immersing microfiber sensor into different concentration E.coli solution, the relationship between resonant wavelength shift and E.coli concentration was analyzed in the range of 103-107cfu/ml. The proposed method is capable of reliable detection of E.coli concentration as low as 103cfu/ml with a fast response time about 10minutes, which makes the real-time detection of E.coli move on a giant step. Additionally, the sensor has great potential to be applied in the fields like environment monitoring and food safety.

Escherichia coli global gene expression in urine from women with urinary tract infection.

PubMed

Hagan, Erin C; Lloyd, Amanda L; Rasko, David A; Faerber, Gary J; Mobley, Harry L T

2010-11-11

Murine models of urinary tract infection (UTI) have provided substantial data identifying uropathogenic E. coli (UPEC) virulence factors and assessing their expression in vivo. However, it is unclear how gene expression in these animal models compares to UPEC gene expression during UTI in humans. To address this, we used a UPEC strain CFT073-specific microarray to measure global gene expression in eight E. coli isolates monitored directly from the urine of eight women presenting at a clinic with bacteriuria. The resulting gene expression profiles were compared to those of the same E. coli isolates cultured statically to exponential phase in pooled, sterilized human urine ex vivo. Known fitness factors, including iron acquisition and peptide transport systems, were highly expressed during human UTI and support a model in which UPEC replicates rapidly in vivo. While these findings were often consistent with previous data obtained from the murine UTI model, host-specific differences were observed. Most strikingly, expression of type 1 fimbrial genes, which are among the most highly expressed genes during murine experimental UTI and encode an essential virulence factor for this experimental model, was undetectable in six of the eight E. coli strains from women with UTI. Despite the lack of type 1 fimbrial expression in the urine samples, these E. coli isolates were generally capable of expressing type 1 fimbriae in vitro and highly upregulated fimA upon experimental murine infection. The findings presented here provide insight into the metabolic and pathogenic profile of UPEC in urine from women with UTI and represent the first transcriptome analysis for any pathogenic E. coli during a naturally occurring infection in humans.

Division Planes Alternate in Spherical Cells of Escherichia coli

PubMed Central

Begg, K. J.; Donachie, W. D.

1998-01-01

In the spherical cells of Escherichia coli rodA mutants, division is initiated at a single point, from which a furrow extends progressively around the cell. Using “giant” rodA ftsA cells, we confirmed that each new division furrow is initiated at the midpoint of the previous division plane and runs perpendicular to it. PMID:9573213

Reassessing Escherichia coli as a cell factory for biofuel production.

PubMed

Wang, Chonglong; Pfleger, Brian F; Kim, Seon-Won

2017-06-01

Via metabolic engineering, industrial microorganisms have the potential to convert renewable substrates into a wide range of biofuels that can address energy security and environmental challenges associated with current fossil fuels. The user-friendly bacterium, Escherichia coli, remains one of the most frequently used hosts for demonstrating production of biofuel candidates including alcohol-, fatty acid- and terpenoid-based biofuels. In this review, we summarize the metabolic pathways for synthesis of these biofuels and assess enabling technologies that assist in regulating biofuel synthesis pathways and rapidly assembling novel E. coli strains. These advances maintain E. coli's position as a prominent host for developing cell factories for biofuel production. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

PubMed

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.

Immunologic Control of Diarrheal Disease Due to Enterotoxigenic Escherichia coli

DTIC Science & Technology

1984-01-01

Classical Enteropathogenic (Serotyped) Escherichia coli Strains of Proven Pathogenicity. Infect. Immun. 38:798-801, 1982. 8. Levine, M.M. Vacunas Contra...Microbiol., 18:808-815, 1983. 8 15. Levine, M.M., Lanata, C. Progresos en Vacunas Contra Diarrea Bacteriana. Adelantos Microbiol. Enferm. Inf., 2:67-117

Persistence of Escherichia coli in manure-amended soil in Pennsylvania

USDA-ARS?s Scientific Manuscript database

Potential for pathogen transfer from soils amended with untreated animal manure to crops and the frequent occurrence of foodborne illness outbreaks involving Escherichia coli O157:H7 prompted the FDA proposal requiring a 9-month waiting period before harvesting produce from manure-amended fields. A...

Detection of Escherichia Coli O157:H7 in Fecal Samples in Meat Goats

ERIC Educational Resources Information Center

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…

Escherichia coli ST131, an Intriguing Clonal Group

PubMed Central

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

Perspectives on super-shedding of Escherichia coli O157:H7 by cattle

USDA-ARS?s Scientific Manuscript database

Escherichia coli O157:H7 is a foodborne pathogen that causes illness in humans worldwide. Cattle are the primary reservoir of this bacterium with the concentration and frequency of E. coli O157:H7 shedding varying greatly among individuals. The term “supershedder” has been applied to cattle that sh...

Lethality prediction for Escherichia coli 0157:H7 and Uropathogenic E. coli in ground chicken treated with high pressure processing and trans-cinnamaldehyde

USDA-ARS?s Scientific Manuscript database

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...

Asymptomatic bacteriuria in adults.

PubMed

Colgan, Richard; Nicolle, Lindsay E; McGlone, Andrew; Hooton, Thomas M

2006-09-15

A common dilemma in clinical medicine is whether to treat asymptomatic patients who present with bacteria in their urine. There are few scenarios in which antibiotic treatment of asymptomatic bacteruria has been shown to improve patient outcomes. Because of increasing antimicrobial resistance, it is important not to treat patients with asymptomatic bacteriuria unless there is evidence of potential benefit. Women who are pregnant should be screened for asymptomatic bacteriuria in the first trimester and treated, if positive. Treating asymptomatic bacteriuria in patients with diabetes, older persons, patients with or without indwelling catheters, or patients with spinal cord injuries has not been found to improve outcomes.

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

PubMed

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

2016-09-09

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. coli O104:H4 in Europe in 2011. We assessed the opportunities for E. coli carrying the aggR and stx genes to emerge in 'backyard' farms in south-east Asia. Faecal samples collected from 204 chicken farms; 204 farmers and 306 age- and gender-matched individuals not exposed to poultry farming were plated on MacConkey agar plates with and without antimicrobials being supplemented. Sweep samples obtained from MacConkey agar plates without supplemented antimicrobials were screened by multiplex PCR for the detection of the stx1, stx2 and aggR genes. One chicken farm sample each (0.5 %) contained the stx1 and the aggR gene. Eleven (2.4 %) human faecal samples contained the stx1 gene, 2 samples (0.4 %) contained stx2 gene, and 31 (6.8 %) contained the aggR gene. From 46 PCR-positive samples, 205 E. coli isolates were tested for the presence of stx1, stx2, aggR, wzx O104 and fliC H4 genes. None of the isolates simultaneously contained the four genetic markers associated with E. coli O104:H4 epidemic strain (aggR, stx2, wzx O104 and fliC H4 ). Of 34 EAEC, 64.7 % were resistant to 3(rd)-generation cephalosporins. These results indicate that in southern Vietnam, the human population is a more likely reservoir of aggR and stx gene carrying E. coli than the chicken population. However, conditions for transmission of isolates and/or genes between human and animal reservoirs resulting in the emergence of highly virulent E. coli strains are still favorable, given the nature of'backyard' farms in Vietnam.

Interaction of Escherichia coli with growing salad spinach plants.

PubMed

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.

A homolog of an Escherichia coli phosphate-binding protein gene from Xanthomonas oryzae pv. oryzae

NASA Technical Reports Server (NTRS)

Hopkins, C. M.; White, F. F.; Heaton, L. A.; Guikema, J. A.; Leach, J. E.; Spooner, B. S. (Principal Investigator)

1995-01-01

A Xanthomonas oryzae pv. oryzae gene with sequence similarity to an Escherichia coli phosphate-binding protein gene (phoS) produces a periplasmic protein of apparent M(r) 35,000 when expressed in E. coli. Amino terminal sequencing revealed that a signal peptide is removed during transport to the periplasm in E. coli.

GENETIC CONTROL OF RESTRICTION AND MODIFICATION IN ESCHERICHIA COLI1

PubMed Central

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

Correlation of Resistance to Proflavine and Penicillin in Escherichia coli

PubMed Central

McKellar, Robin C.; McKenzie, Colin N.; Kushner, Donn J.

1976-01-01

A number of proflavine (PF)-resistant mutants of Escherichia coli B were also resistant to penicillin and cephalothin. Mutants resistant to 1.0 mM PF were 10 times more penicillin resistant than were the PF-susceptible, wild-type cells. Single-step mutants selected for resistance to either PF or penicillin were also resistant to the other drug. None of the resistant mutants tested possessed β-lactamase activity. These results suggest that resistance to PF and penicillin in E. coli B may be due to permeability changes in the cell envelope. PMID:791110

Surface display of Salmonella epitopes in Escherichia coli and Staphylococcus carnosus.

PubMed

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

Cloning and expression of L-asparaginase gene in Escherichia coli.

PubMed

Wang, Y; Qian, S; Meng, G; Zhang, S

2001-08-01

The L-asparaginase (ASN) from Escherichia coli AS1.357 was cloned as a DNA fragment generated using polymerase chain reaction technology and primers derived from conserved regions of published ASN gene sequences. Recombinant plasmid pASN containing ASN gene and expression vector pBV220 was transformed in different E. coli host strains. The activity and expression level of ASN in the engineering strains could reach 228 IU/mL of culture fluid and about 50% of the total soluble cell protein respectively, more than 40-fold the enzyme activity of the wild strain. The recombinant plasmid in E. coli AS1.357 remained stable after 72 h of cultivation and 5 h of heat induction without selective pressure. The ASN gene of E. coli AS1.357 was sequenced and had high homology compared to the reported data.

Efficient Extracellular Expression of Phospholipase D in Escherichia Coli with an Optimized Signal Peptide

NASA Astrophysics Data System (ADS)

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.

Development of functionalised polyelectrolyte capsules using filamentous Escherichia coli cells.

PubMed

Lederer, Franziska L; Günther, Tobias J; Weinert, Ulrike; Raff, Johannes; Pollmann, Katrin

2012-12-23

Escherichia coli is one of the best studied microorganisms and finds multiple applications especially as tool in the heterologous production of interesting proteins of other organisms. The heterologous expression of special surface (S-) layer proteins caused the formation of extremely long E. coli cells which leave transparent tubes when they divide into single E. coli cells. Such natural structures are of high value as bio-templates for the development of bio-inorganic composites for many applications. In this study we used genetically modified filamentous Escherichia coli cells as template for the design of polyelectrolyte tubes that can be used as carrier for functional molecules or particles. Diversity of structures of biogenic materials has the potential to be used to construct inorganic or polymeric superior hybrid materials that reflect the form of the bio-template. Such bio-inspired materials are of great interest in diverse scientific fields like Biology, Chemistry and Material Science and can find application for the construction of functional materials or the bio-inspired synthesis of inorganic nanoparticles. Genetically modified filamentous E. coli cells were fixed in 2% glutaraldehyde and coated with alternating six layers of the polyanion polyelectrolyte poly(sodium-4styrenesulfonate) (PSS) and polycation polyelectrolyte poly(allylamine-hydrochloride) (PAH). Afterwards we dissolved the E. coli cells with 1.2% sodium hypochlorite, thus obtaining hollow polyelectrolyte tubes of 0.7 μm in diameter and 5-50 μm in length. For functionalisation the polyelectrolyte tubes were coated with S-layer protein polymers followed by metallisation with Pd(0) particles. These assemblies were analysed with light microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and transmission electron microscopy. The thus constructed new material offers possibilities for diverse applications like novel catalysts or metal nanowires for electrical devices

Contaminated Stream Water as Source for Escherichia coli O157 Illness in Children.

PubMed

Probert, William S; Miller, Glen M; Ledin, Katya E

2017-07-01

In May 2016, an outbreak of Shiga toxin-producing Escherichia coli O157 infections occurred among children who had played in a stream flowing through a park. Analysis of E. coli isolates from the patients, stream water, and deer and coyote scat showed that feces from deer were the most likely source of contamination.

Seagulls and Beaches as Reservoirs for Multidrug-Resistant Escherichia coli

PubMed Central

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

2010-01-01

A variety of extended-spectrum β-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. PMID:20031053

Increased serum procalcitonin levels in pregnant patients with asymptomatic bacteriuria.

PubMed

Bilir, Filiz; Akdemir, Nermin; Ozden, Selcuk; Cevrioglu, A Serhan; Bilir, Cemil

2013-09-05

Among the pregnancy urinary tract infections, asymptomatic bacteriuria (ASB) is the most common one. Untreated ASB can progress to pyelonephritis in 30-50% of the patients and can also result in prematurity in 27% of the pregnancy so it needs immediate diagnosis and treatment. In this study, we wanted to evaluate procalcitonin levels, compared to other inflammatory in pregnant women with ASB. The study was designed between the period of January 2012 and February 2013 at Sakarya University School of Medicine, Department of Gynecology and Obstetrics. The study population included 30 pregnant patients with asymptomatic bacteriuria and 39 healthy pregnant controls. Mean age was 28 (SD, 5.5) of the study population; mean maternal weight was 70 (SD, 8) kilogram. There were no statically significant differences between the groups according to the routine biochemical parameters, but gestational age was significantly lower in the ASB group compared to the controls (20.4 vs 28.6, respectively; p < 0.001). Serum procalcitonin levels were negative in all of the controls. In ASB group, 9 (30%) patients had procalcitonin levels greater than >0.05 ng/ml and 21(70%) patients had negative procalcitonin levels (Chi-squrae, p < 0.001). The sensitivity and specificity of procalcitonin assay for ASB was calculated as 30% and 100%, respectively. The positive predictive value was 100% and the negative predictive value was 65%. The most frequent microorganisms in the urine culture were Escherichia coli (26 patients, 87%), Proteus mirabilis (3 patients, 10%) and Klebsiella (1 patient, 3%) in the ASB group. We experienced four (44%) recurrences among nine positive procalcitonin in ASB patients after completion of treatment of the first ASB diagnosis. Procalcitonin levels were significantly higher in ASB group than the control group and serum procalcitonin levels were higher in pregnant women with recurrent ASB. This finding is an important result revealed that high procalcitonin level can

Transferability of antimicrobial resistance from multidrug-resistant Escherichia coli isolated from cattle in the USA to E. coli and Salmonella Newport recipients

USDA-ARS?s Scientific Manuscript database

The objective of this study was to evaluate conjugative transfer of cephalosporin resistance among (n=100) strains of multi-drug resistant Escherichia coli (MDRE) to Salmonella Newport and E. coli DH5-alpha recipients. To accomplish this, phenotypic and genotypic profiles were determined for MDRE, ...

The first 30 years of Shiga toxin-producing Escherichia coli in cattle production: Incidence, preharvest ecology, and management

USDA-ARS?s Scientific Manuscript database

Of the 700 serotypes of Escherichia coli, most are commensal; however, some range from mildly to highly pathogenic and can cause death. The disease-causing enterovirulent E. coli are classified as: Enterotoxigenic E. coli (ETEC), Enteropathogenic E. coli (EPEC), Enteroinvasive E. coli (EIEC), and ...

Seasonal influence of environmental variables and artificial aeration on Escherichia coli in small urban lakes.

PubMed

Durham, Bart W; Porter, Lucy; Webb, Allie; Thomas, Joshua

2016-12-01

This study investigated patterns of Escherichia coli in urban lakes in Lubbock, Texas. Specific objectives were to (1) document seasonal patterns in abundance of E. coli over a 3-year period, (2) identify environmental factors, including effects of migratory geese and artificial aeration devices that may influence E. coli abundance, and (3) determine if E. coli abundance over time was similar for individual lakes. Water samples were collected monthly for 36 months from six lakes, three of which contained artificial aeration devices (fountains). Regression models were constructed to determine which environmental variables most influence E. coli abundance in summer and winter seasons. Escherichia coli is present in the lakes of Lubbock, Texas year-round and typically exceeds established bacterial thresholds for recreational waters. Models most frequently contained pH and dissolved oxygen as predictor variables and explained from 17.4% to 92.4% of total variation in E. coli. Lakes with fountains had a higher oxygen concentration during summer and contained consistently less E. coli. We conclude that solar irradiation in synergy with pH and dissolved oxygen is the primary control mechanism for E. coli in study lakes, and that fountains help control abundance of fecal bacteria within these systems.

Chemotaxis towards autoinducer 2 mediates autoaggregation in Escherichia coli

PubMed Central

Laganenka, Leanid; Colin, Remy; Sourjik, Victor

2016-01-01

Bacteria communicate by producing and sensing extracellular signal molecules called autoinducers. Such intercellular signalling, known as quorum sensing, allows bacteria to coordinate and synchronize behavioural responses at high cell densities. Autoinducer 2 (AI-2) is the only known quorum-sensing molecule produced by Escherichia coli but its physiological role remains elusive, although it is known to regulate biofilm formation and virulence in other bacterial species. Here we show that chemotaxis towards self-produced AI-2 can mediate collective behaviour—autoaggregation—of E. coli. Autoaggregation requires motility and is strongly enhanced by chemotaxis to AI-2 at physiological cell densities. These effects are observed regardless whether cell–cell interactions under particular growth conditions are mediated by the major E. coli adhesin (antigen 43) or by curli fibres. Furthermore, AI-2-dependent autoaggregation enhances bacterial stress resistance and promotes biofilm formation. PMID:27687245

Autodisplay of an avidin with biotin-binding activity on the surface of Escherichia coli.

PubMed

Pardavé-Alejandre, H D; Alvarado-Yaah, J E; Pompa-Mera, E N; Muñoz-Medina, J E; Sárquiz-Martínez, B; Santacruz-Tinoco, C E; Manning-Cela, R G; Ortíz-Navarrete, V; López-Macías, C; González-Bonilla, C R

2018-03-01

To display a recombinant avidin fused to the autotransporter ShdA to bind biotinylated molecules on the surface of Escherichia coli. Two chimeric protein constructs containing avidin fused to the autotransporter ShdA were expressed on the surface of Escherichia coli DH5α. One fusion protein contained 476 amino acids of the ShdA α and β domains, whereas the second consisted of a 314 amino acid from α and truncated β domains. Protein production was verified by SDS-PAGE using an antibody to the molecular FLAG-tag. The surface display of the avidin-shdA fusion protein was confirmed by confocal microscopy and flow cytometry analysis, and the biotin-binding activity was evaluated by fluorescence microscopy and flow cytometry using biotin-4-fluorescein and biotinylated-ovalbumin (OVA). Expression of a recombinant avidin with biotin-binding activity on the surface of E. coli was achieved using the autotransporter ShdA. This system is an alternative to bind biotinylated molecules to E. coli.

Release of colicin E2 from Escherichia coli.

PubMed

Pugsley, A P; Rosenbusch, J P

1981-07-01

Treatment of Escherichia coli K-12(ColE2.P9) with 500 ng of mitomycin C per ml resulted in rapid and almost synchronous colicin E2 production. Colicin accumulated outside the cytoplasmic membrane, most probably in the periplasmic space. Colicin release occurred during a period in which the turbidity of the culture declined markedly. Periplasmic alkaline phosphatase was released during the same period, but cytoplasmic beta-galactosidase release was delayed.

Multi-locus variable number tandem repeat analysis for Escherichia coli causing extraintestinal infections.

PubMed

Manges, Amee R; Tellis, Patricia A; Vincent, Caroline; Lifeso, Kimberley; Geneau, Geneviève; Reid-Smith, Richard J; Boerlin, Patrick

2009-11-01

Discriminatory genotyping methods for the analysis of Escherichia coli other than O157:H7 are necessary for public health-related activities. A new multi-locus variable number tandem repeat analysis protocol is presented; this method achieves an index of discrimination of 99.5% and is reproducible and valid when tested on a collection of 836 diverse E. coli.

Detection of Escherichia coli, Salmonella species, and Vibrio cholerae in tap water and bottled drinking water in Isfahan, Iran.

PubMed

Momtaz, Hassan; Dehkordi, Farhad Safarpoor; Rahimi, Ebrahim; Asgarifar, Amin

2013-06-07

The quality of drinking water has an important role in human infection and disease. This study was aimed at comparing polymerase chain reaction and culture in detecting Escherichia coli, Salmonella species and Vibrio cholera in tape water and bottled drinking water in various seasons in Isfahan province, Iran. A total of 448 water samples from tap water and bottled mineral water were taken over 6 months, from July 2010 to December 2010, and after filtration, samples were examined by culture and polymerase chain reaction methods for detection of Escherichia coli, Salmonella species, and Vibrio cholerae. The culture method showed that 34 (7.58%), 4 (0.89%) and 3 (0.66%) of all 448 water samples were positive for Escherichia coli, Salmonella species, and Vibrio cholera, respectively. The uidA gene from Escherichia coli, IpaB gene from Salmonella species, and epsM gene from Vibrio cholera were detected in 38 (26.38%), 5 (3.47%), and 3 (2.08%) of 144 tap-water samples, respectively. Escherichia coli was detected in 8 (2.63%) of 304 samples of bottled drinking water from 5 companies. The water of southern part of Isfahan and company 5 had the highest prevalence of bacteria. The Escherichia coli water contamination was significantly higher (P < 0.05) in the hot seasons (July-August) than cold (November-December) seasons and in company 5 than other companies. There were significant differences (P < 0.05) for the prevalence of bacteria between the tap waters of southern part and tap waters of central part of Isfahan. This study showed that the polymerase chain reaction assays can be an extremely accurate, fast, safe, sensitive and specific approach to monitor drinking water quality from purification facilities and bottled water companies. Also, our study confirmed the presence of Escherichia coli, Salmonella species, and Vibrio cholerae as water-borne pathogens in tap water and bottled drinking water of Isfahan, Iran. The present study showed the important public health

Detection of Escherichia coli, Salmonella species, and Vibrio cholerae in tap water and bottled drinking water in Isfahan, Iran

PubMed Central

2013-01-01

Background The quality of drinking water has an important role in human infection and disease. This study was aimed at comparing polymerase chain reaction and culture in detecting Escherichia coli, Salmonella species and Vibrio cholera in tape water and bottled drinking water in various seasons in Isfahan province, Iran. Methods A total of 448 water samples from tap water and bottled mineral water were taken over 6 months, from July 2010 to December 2010, and after filtration, samples were examined by culture and polymerase chain reaction methods for detection of Escherichia coli, Salmonella species, and Vibrio cholerae. Results The culture method showed that 34 (7.58%), 4 (0.89%) and 3 (0.66%) of all 448 water samples were positive for Escherichia coli, Salmonella species, and Vibrio cholera, respectively. The uidA gene from Escherichia coli, IpaB gene from Salmonella species, and epsM gene from Vibrio cholera were detected in 38 (26.38%), 5 (3.47%), and 3 (2.08%) of 144 tap-water samples, respectively. Escherichia coli was detected in 8 (2.63%) of 304 samples of bottled drinking water from 5 companies. The water of southern part of Isfahan and company 5 had the highest prevalence of bacteria. The Escherichia coli water contamination was significantly higher (P < 0.05) in the hot seasons (July-August) than cold (November-December) seasons and in company 5 than other companies. There were significant differences (P < 0.05) for the prevalence of bacteria between the tap waters of southern part and tap waters of central part of Isfahan. Conclusions This study showed that the polymerase chain reaction assays can be an extremely accurate, fast, safe, sensitive and specific approach to monitor drinking water quality from purification facilities and bottled water companies. Also, our study confirmed the presence of Escherichia coli, Salmonella species, and Vibrio cholerae as water-borne pathogens in tap water and bottled drinking water of Isfahan, Iran. The

Enterobacteria identification and detection of diarrheagenic Escherichia coli in a Port Complex

PubMed Central

Costa, Clarissa Frota Macatrão; Neto, Valério Monteiro; Santos, Bruno Rafael de Carvalho; Costa, Bruno Rafael Rabelo; Azevedo, Alexandre; Serra, Josilene Lima; Mendes, Hermínio Benítez Rabello; Nascimento, Adenilde Ribeiro; Mendes, Mariana Bonfim Pinto; Kuppinger, Oliver

2014-01-01

The Port Complex of Maranhão (PCM) is the second largest port complex in Brazil, receiving ships with large volumes of ballast water. To evaluate the microbiological quality of its waters, physicochemical parameters (pH and salinity), the number of coliforms (thermotolerants and totals), and the presence of enterobacterias and diarrheagenic Escherichia coli strains were analyzed. In order to identify the presence of E. coli virulence genes target regions of the stx, elt, est, aggR, CVD432, ipaH and eae nucleotide sequences were studied. The presence of totals and thermotolerants coliforms were positive. Analyzing the salinity parameter, a significant increase in total coliforms was observed during the rainy season. We identified the species Escherichia coli, Proteus mirabilis, Citrobacter freundii, Proteus vulgaris, Klebsiella pneumoniae, Klebsiella ozaenae, Morganella morganii, Enterobacter cloacae and Edwardsiella tarda. Out of the 51 E. coli isolated, two were positive for the elt gene and one was positive for the CVD432 sequence, features of enterotoxigenic and enteroaggregative strains, respectively. This study reveals that the PCM is contaminated by enterobacteria and diarrheagenic E.coli thus providing evidence regarding the risk of these bacteria being carried by ships to other countries, and draws attention to the input of fecal bacteria brought by ships in the port waters of Maranhão. PMID:25477930

Quinolone-resistant Escherichia coli in Poultry Farming.

PubMed

Hricová, Kristýna; Röderová, Magdaléna; Pudová, Vendula; Hanulík, Vojtěch; Halová, Dana; Julínková, Pavla; Dolejská, Monika; Papoušek, Ivo; Bardoň, Jan

2017-06-01

Increasing bacterial resistance to quinolone antibiotics is apparent in both humans and animals. For humans, a potential source of resistant bacteria may be animals or their products entering the human food chain, for example poultry. Between July 2013 and September 2014, samples were collected and analyzed in the Moravian regions of the Czech Republic to isolate the bacterium Escherichia coli. As a result, 212 E. coli isolates were obtained comprising 126 environmental isolates from poultry houses and 86 isolates from cloacal swabs from market-weight turkeys. Subsequently, the E. coli isolates were tested for susceptibility to selected antibiotics. Resistance of the poultry isolates to quinolones ranged from 53% to 73%. Additionally, the presence of plasmid-mediated resistance genes was studied. The genes were confirmed in 58% of the tested strains. The data on resistance of isolates from poultry were compared with results of resistance tests in human isolates obtained in the same regions. The high levels of resistance determined by both phenotyping and genotyping methods and reported in the present study confirm the fact that the use of fluoroquinolones in poultry should be closely monitored. Copyright© by the National Institute of Public Health, Prague 2017.

Escherichia coli growth under modeled reduced gravity

NASA Technical Reports Server (NTRS)

Baker, Paul W.; Meyer, Michelle L.; Leff, Laura G.

2004-01-01

Bacteria exhibit varying responses to modeled reduced gravity that can be simulated by clino-rotation. When Escherichia coli was subjected to different rotation speeds during clino-rotation, significant differences between modeled reduced gravity and normal gravity controls were observed only at higher speeds (30-50 rpm). There was no apparent affect of removing samples on the results obtained. When E. coli was grown in minimal medium (at 40 rpm), cell size was not affected by modeled reduced gravity and there were few differences in cell numbers. However, in higher nutrient conditions (i.e., dilute nutrient broth), total cell numbers were higher and cells were smaller under reduced gravity compared to normal gravity controls. Overall, the responses to modeled reduced gravity varied with nutrient conditions; larger surface to volume ratios may help compensate for the zone of nutrient depletion around the cells under modeled reduced gravity.

A glimpse of Escherichia coli O157:H7 survival in soils from eastern China

USDA-ARS?s Scientific Manuscript database

Escherichia coli O157:H7 (E. coli O157:H7) is an important food-borne pathogen, which continues to be a major public health concern worldwide. It is known that E. coli O157:H7 survive in soil environment might result in the contamination of fresh produce or water source. To investigate how the soils...

Escherichia coli K1 invasion of human brain microvascular endothelial cells.

PubMed

Loh, Lip Nam; Ward, Theresa H

2012-01-01

The pathogenic Escherichia coli strain E. coli K1 is a primary causative agent of neonatal meningitis. Understanding how these bacteria cross the blood-brain barrier is vital to develop therapeutics. Here, we describe the use of live-cell imaging techniques to study E. coli K1 interactions with cellular markers following infection of human brain microvascular endothelial cells, a model system of the blood-brain barrier. We also discuss optimization of endothelial cell transfection conditions using nonviral transfection technique, bacterial labeling techniques, and in vitro assays to screen for fluorescent bacteria that retain their ability to invade host cells. Copyright © 2012 Elsevier Inc. All rights reserved.

Prevalence and multidrug resistance of Escherichia coli from community acquired infections in Lagos, Nigeria

USDA-ARS?s Scientific Manuscript database

Escherichia coli is one of the most frequent causes of bacterial infections among humans. The emergence of multi-drug resistance (MDR; resistance to >2 more antimicrobials) in E. coli is of great concern due to the complications encountered in its treatment in a resource constrained economy. In th...

Sensitivity of Mixed Populations of Staphylococcus aureus and Escherichia coli to Mercurials

PubMed Central

Stutzenberger, F. J.; Bennett, E. O.

1965-01-01

Staphylococcus aureus was found to have a higher resistance to merbromin and mercuric chloride in the presence of Escherichia coli. The protective effect of the gram-negative organism on S. aureus was due to the production of extracellular glutathione and hydrogen sulfide and to an unequal distribution of the inhibitor between the two species. S. aureus did not significantly influence the resistance of E. coli to mercurials. PMID:14339264

Synthesis of avenanthramides using engineered Escherichia coli.

PubMed

Lee, Su Jin; Sim, Geun Young; Kang, Hyunook; Yeo, Won Seok; Kim, Bong-Gyu; Ahn, Joong-Hoon

2018-03-22

Hydroxycinnamoyl anthranilates, also known as avenanthramides (avns), are a group of phenolic alkaloids with anti-inflammatory, antioxidant, anti-itch, anti-irritant, and antiatherogenic activities. Some avenanthramides (avn A-H and avn K) are conjugates of hydroxycinnamic acids (HC), including p-coumaric acid, caffeic acid, and ferulic acid, and anthranilate derivatives, including anthranilate, 4-hydroxyanthranilate, and 5-hydroxyanthranilate. Avns are primarily found in oat grain, in which they were originally designated as phytoalexins. Knowledge of the avns biosynthesis pathway has now made it possible to synthesize avns through a genetic engineering strategy, which would help to further elucidate their properties and exploit their beneficial biological activities. The aim of the present study was to synthesize natural avns in Escherichia coli to serve as a valuable resource. We synthesized nine avns in E. coli. We first synthesized avn D from glucose in E. coli harboring tyrosine ammonia lyase (TAL), 4-coumarate:coenzyme A ligase (4CL), anthranilate N-hydroxycinnamoyl/benzoyltransferase (HCBT), and anthranilate synthase (trpEG). A trpD deletion mutant was used to increase the amount of anthranilate in E. coli. After optimizing the incubation temperature and cell density, approximately 317.2 mg/L of avn D was synthesized. Avn E and avn F were then synthesized from avn D, using either E. coli harboring HpaBC and SOMT9 or E. coli harboring HapBC alone, respectively. Avn A and avn G were synthesized by feeding 5-hydroxyanthranilate or 4-hydroxyanthranilate to E. coli harboring TAL, 4CL, and HCBT. Avn B, avn C, avn H, and avn K were synthesized from avn A or avn G, using the same approach employed for the synthesis of avn E and avn F from avn D. Using different HCs, nine avns were synthesized, three of which (avn D, avn E, and avn F) were synthesized from glucose in E. coli. These diverse avns provide a strategy to synthesize both natural and unnatural avns

Inactivation and Gene Expression of a Virulent Wastewater Escherichia coli Strain and the Nonvirulent Commensal Escherichia coli DSM1103 Strain upon Solar Irradiation.

PubMed

Al-Jassim, Nada; Mantilla-Calderon, David; Wang, Tiannyu; Hong, Pei-Ying

2017-04-04

This study examined the decay kinetics and molecular responses of two Escherichia coli strains upon solar irradiation. The first is E. coli PI-7, a virulent and antibiotic-resistant strain that was isolated from wastewater and carries the emerging NDM-1 antibiotic resistance gene. The other strain, E. coli DSM1103, displayed lower virulence and antibiotic resistance than E. coli PI-7. In a buffer solution, E. coli PI-7 displayed a longer lag phase prior to decay and a longer half-life compared with E. coli DSM1103 (6.64 ± 0.63 h and 2.85 ± 0.46 min vs 1.33 ± 0.52 h and 2.04 ± 0.36 min). In wastewater, both E. coli strains decayed slower than they did in buffer. Although solar irradiation remained effective in reducing the numbers of both strains by more than 5-log 10 in <24 h, comparative genomics and transcriptomics revealed differences in the genomes and overall regulation of genes between the two E. coli strains. A wider arsenal of genes related to oxidative stress, cellular repair and protective mechanisms were upregulated in E. coli PI-7. Subpopulations of E. coli PI-7 expressed genes related to dormancy and persister cell formation during the late decay phase, which may have accounted for its prolonged persistence. Upon prolonged solar irradiation, both E. coli strains displayed upregulation of genes related to horizontal gene transfer and antibiotic resistance. Virulence functions unique to E. coli PI-7 were also upregulated. Our findings collectively indicated that, whereas solar irradiation is able to reduce total cell numbers, viable E. coli remained and expressed genes that enable survival despite solar treatment. There remains a need for heightened levels of concern regarding risks arising from the dissemination of E. coli that may remain viable in wastewater after solar irradiation.

Genome Sequences of 228 Shiga Toxin-Producing Escherichia coli Isolates and 12 Isolates Representing Other Diarrheagenic E. coli Pathotypes

PubMed Central

Strockbine, Nancy; Changayil, Shankar; Ranganathan, Satishkumar; Zhao, Kun; Weil, Ryan; MacCannell, Duncan; Sabol, Ashley; Schmidtke, Amber; Martin, Haley; Stripling, Devon; Ribot, Efrain M.; Gerner-Smidt, Peter

2014-01-01

Shiga toxin-producing Escherichia coli (STEC) are a common cause for food-borne diarrheal illness outbreaks and sporadic cases. Here, we report the availability of the draft genome sequences of 228 STEC strains representing 32 serotypes with known pulsed-field gel electrophoresis (PFGE) types and epidemiological relationships, as well as 12 strains representing other diarrheagenic E. coli pathotypes. PMID:25103754

In vitro Clostridium perfringens and Escherichia coli toxin adsorption of Varium

USDA-ARS?s Scientific Manuscript database

Enteric disease agents, such as Clostridium perfringens and Escherichia coli, produce detrimental biotoxins that cause significant economic loss annually in the poultry industry. The objective of this study was to determine the in vitro biotoxin adsorption capability of Varium. An enzyme-linked im...

Effect of Various Conditions on Accumulation of Oxytetracycline in Escherichia coli

PubMed Central

Izaki, Kazuo; Arima, Kei

1965-01-01

Izaki, Kazuo (University of Tokyo, Tokyo, Japan), and Kei Arima. Effect of various conditions on accumulation of oxytetracycline in Escherichia coli. J. Bacteriol. 89:1335–1339. 1965.—Accumulation of large amounts of oxytetracycline occurred in Escherichia coli when the cells were incubated with high concentrations of oxytetracycline (100 to 400 μg/ml) in nutrient broth or in a medium containing glucose, K2HPO4, and MgSO4. In the absence of glucose or MgSO4, the accumulation was very small. The optimal pH for accumulation was about 6.5. Manganous ion could replace Mg++ in promoting the accumulation, though with decreased effectiveness. Malate and succinate were effective promoters of accumulation as well as glucose. Accumulation was inhibited at low temperatures or in the presence of metabolic inhibitors such as 2,4-dinitrophenol or sodium azide. Images PMID:14293007

The Inhibition of Escherichia coli Biofilm Formation by Gallium Nitrate-Modified Titanium.

PubMed

Zhu, Yuanyuan; Qiu, Yan; Chen, Ruiqi; Liao, Lianming

2015-08-01

Periprosthetic infections are notoriously difficult to treat due to biofilm formation. Previously, we reported that gallium-EDTA attached to PVC (polyvinyl chloride) surface could prevent bacterial colonization. Herein we examined the effect of this gallium-EDTA complex on Escherichia coli biofilm formation on titanium. It was clearly demonstrated that gallium nitrate significantly inhibited the growth and auto-aggregation of Escherichia coli. Furthermore, titanium with gallium-EDTA coating resisted bacterial colonization as indicated by crystal violet staining. When the chips were immersed in human serum and incubated at 37 °C, they demonstrated significant antimicrobial activity after more than 28 days of incubation. These findings indicate that gallium-EDTA coating of implants can result in a surface that can resist bacterial colonization. This technology holds great promise for the prevention and treatment of periprosthetic infections.

Peptidoglycan Hydrolases of Escherichia coli

PubMed Central

van Heijenoort, Jean

2011-01-01

Summary: The review summarizes the abundant information on the 35 identified peptidoglycan (PG) hydrolases of Escherichia coli classified into 12 distinct families, including mainly glycosidases, peptidases, and amidases. An attempt is also made to critically assess their functions in PG maturation, turnover, elongation, septation, and recycling as well as in cell autolysis. There is at least one hydrolytic activity for each bond linking PG components, and most hydrolase genes were identified. Few hydrolases appear to be individually essential. The crystal structures and reaction mechanisms of certain hydrolases having defined functions were investigated. However, our knowledge of the biochemical properties of most hydrolases still remains fragmentary, and that of their cellular functions remains elusive. Owing to redundancy, PG hydrolases far outnumber the enzymes of PG biosynthesis. The presence of the two sets of enzymes acting on the PG bonds raises the question of their functional correlations. It is difficult to understand why E. coli keeps such a large set of PG hydrolases. The subtle differences in substrate specificities between the isoenzymes of each family certainly reflect a variety of as-yet-unidentified physiological functions. Their study will be a far more difficult challenge than that of the steps of the PG biosynthesis pathway. PMID:22126997

Cadmium tolerance and antibiotic resistance in Escherichia coli isolated from waste stabilization ponds.

PubMed

Patra, Sova; Das, T K; Avila, C; Cabello, V; Castillo, F; Sarkar, D; Lahiri, Susmita; Jana, B B

2012-04-01

The incidence pattern of cadmium tolerance and antibiotics resistance by Escherichia coli was examined periodically from the samples of water, sludge and intestine of fish raised in waste stabilization ponds in a sewage treatment plant. Samples of water and sludge were collected from all the selected ponds and were monitored for total counts of fecal coliform (FC), total coliform (TC) and the population of Escherichia coli, which was also obtained from the intestine of fishes. Total counts of both FC and TC as well as counts of E. coli were markedly reduced from the facultative pond to the last maturation pond. Tolerance limit to cadmium by E. coli tended to decline as the distance of the sewage effluent from the source increased; the effective lethal concentration of cadmium ranged from 0.1 mM in split chamber to 0.05 mM in first maturation pond. E. coli isolated from water, sludge and fish gut were sensitive to seven out of ten antibiotics tested. It appears that holistic functions mediated through the mutualistic growth of micro algae and heterotrophic bacteria in the waste stabilization ponds were responsible for the promotion of water quality and significant reduction of coliform along the sewage effluent gradient.

AFM study of Escherichia coli RNA polymerase σ⁷⁰ subunit aggregation.

PubMed

Dubrovin, Evgeniy V; Koroleva, Olga N; Khodak, Yulia A; Kuzmina, Natalia V; Yaminsky, Igor V; Drutsa, Valeriy L

2012-01-01

The self-assembly of Escherichia coli RNA polymerase σ⁷⁰ subunit was investigated using several experimental approaches. A novel rodlike shape was reported for σ⁷⁰ subunit aggregates. Atomic force microscopy reveals that these aggregates, or σ⁷⁰ polymers, have a straight rodlike shape 5.4 nm in diameter and up to 300 nm in length. Atomic force microscopy data, Congo red binding assay, and sodium dodecyl sulfate gel electrophoresis confirm the amyloid nature of observed aggregates. The process of formation of rodlike structures proceeds spontaneously under nearly physiological conditions. E. coli RNA polymerase σ⁷⁰ subunit may be an interesting object for investigation of amyloidosis as well as for biotechnological applications that exploit self-assembled bionanostructures. Polymerization of σ⁷⁰ subunit may be a competitive process with its three-dimensional crystallization and association with core RNA polymerase. In this basic science study, the self-assembly of Escherichia coli RNA polymerase σ⁷⁰( subunit was investigated using atomic force microscopy and other complementary approaches. 2012 Elsevier Inc. All rights reserved.

Escherichia coli pathotypes in Pakistan from consecutive floods in 2010 and 2011.

PubMed

Bokhari, Habib; Shah, Muhammad Ali; Asad, Saba; Akhtar, Sania; Akram, Muhammad; Wren, Brendan W

2013-03-01

This study compares Escherichia coli pathotypes circulating among children in Pakistan during the floods of 2010 and 2011 and from sporadic cases outside flood affected areas. Using multiplex polymerase chain reaction 115 of 205 stool samples (56.29%) were positive for diarrheagenic E. coli from specimens taken during the floods compared with 50 of 400 (12.5%) stool samples being positive for sporadic cases. The E. coli pathotypes were categorized as Enteropathogenic E. coli 33 (28.69%) and 13 (26%), Enterotoxigenic E. coli 29 (25.21%) and 15 (30%), Enteroaggregative E. coli 21 (18.2%) and 18 (36%), Enterohemorrhagic E. coli 5 (4.34%) and 1 (2%) from flood and sporadic cases, respectively. Furthermore, patients co-infected with more than one pathotype were 26 (22.60%) and 3 (6%) from flood and sporadic cases, respectively. The study shows an unexpectedly high rate of isolation of E. coli pathotypes suggesting Pakistan as an endemic region that requires active surveillance particularly during flood periods.

Escherichia coli Pathotypes in Pakistan from Consecutive Floods in 2010 and 2011

PubMed Central

Bokhari, Habib; Shah, Muhammad Ali; Asad, Saba; Akhtar, Sania; Akram, Muhammad; Wren, Brendan W.

2013-01-01

This study compares Escherichia coli pathotypes circulating among children in Pakistan during the floods of 2010 and 2011 and from sporadic cases outside flood affected areas. Using multiplex polymerase chain reaction 115 of 205 stool samples (56.29%) were positive for diarrheagenic E. coli from specimens taken during the floods compared with 50 of 400 (12.5%) stool samples being positive for sporadic cases. The E. coli pathotypes were categorized as Enteropathogenic E. coli 33 (28.69%) and 13 (26%), Enterotoxigenic E. coli 29 (25.21%) and 15 (30%), Enteroaggregative E. coli 21 (18.2%) and 18 (36%), Enterohemorrhagic E. coli 5 (4.34%) and 1 (2%) from flood and sporadic cases, respectively. Furthermore, patients co-infected with more than one pathotype were 26 (22.60%) and 3 (6%) from flood and sporadic cases, respectively. The study shows an unexpectedly high rate of isolation of E. coli pathotypes suggesting Pakistan as an endemic region that requires active surveillance particularly during flood periods. PMID:23358642

The Modular Organization of Protein Interactions in Escherichia coli

PubMed Central

Peregrín-Alvarez, José M.; Xiong, Xuejian; Su, Chong; Parkinson, John

2009-01-01

Escherichia coli serves as an excellent model for the study of fundamental cellular processes such as metabolism, signalling and gene expression. Understanding the function and organization of proteins within these processes is an important step towards a ‘systems’ view of E. coli. Integrating experimental and computational interaction data, we present a reliable network of 3,989 functional interactions between 1,941 E. coli proteins (∼45% of its proteome). These were combined with a recently generated set of 3,888 high-quality physical interactions between 918 proteins and clustered to reveal 316 discrete modules. In addition to known protein complexes (e.g., RNA and DNA polymerases), we identified modules that represent biochemical pathways (e.g., nitrate regulation and cell wall biosynthesis) as well as batteries of functionally and evolutionarily related processes. To aid the interpretation of modular relationships, several case examples are presented, including both well characterized and novel biochemical systems. Together these data provide a global view of the modular organization of the E. coli proteome and yield unique insights into structural and evolutionary relationships in bacterial networks. PMID:19798435

[Investigation of metabolic action of Cordyceps sinensis and its cultured mycelia on Escherichia coli by microcalorimetry].

PubMed

Zhou, Dan-Lei; Yan, Dan; Li, Bao-Cai; Wu, Yan-Shu; Xiao, Xiao-He

2009-06-01

This study is to investigate the effect of Cordyceps sinensis and its cultured mycelia on growth and metabolism of Escherichia coli, and microcalorimetric method was carried out to evaluate its biological activity. The study will provide the basis for the quality control of Cordyceps sinensis. Experimental result will show the effect of natural Cordyceps sinensis and its cultured mycelia on growth and metabolism of Escherichia coli, with index of P(1max) and effective rate (E) by microcalorimetry, the data of experiment were studied by cluster analysis. The results showed that Cordyceps sinensis and its cultured mycelia not only can promote growth and metabolism of Escherichia coli but also can regulate the balance of intestinal microecology efficiently. When the concentrations of samples > 6.0 mg mL(-1), natural Cordyceps sinensis can promote the growth and metabolism of Escherichia coli efficiently (P < 0.05) compared with the control group, and have better dose-effect relationship with concentration (r > 0.9), its cultured mycelia does not show conspicuous auxoaction (P > 0.05) and have not dose-effect relationship with concentration (r < 0.6); when the concentration of samples < 6.0 mg mL(-1), all samples does not show conspicuous auxoaction (P > 0.05). Natural Cordyceps sinensis and its cultured mycelia can be distinguished by cluster analysis. Microcalorimetry has a good prospect on the quality evaluation of the traditional Chinese medicine.

Complete Genome Sequence of the Avian Pathogenic Escherichia coli Strain APEC O78

PubMed Central

Mangiamele, Paul; Nicholson, Bryon; Wannemuehler, Yvonne; Seemann, Torsten; Logue, Catherine M.; Li, Ganwu; Tivendale, Kelly A.

2013-01-01

Colibacillosis, caused by avian pathogenic Escherichia coli (APEC), is a significant disease, causing extensive animal and financial losses globally. Because of the significance of this disease, more knowledge is needed regarding APEC's mechanisms of virulence. Here, we present the fully closed genome sequence of a typical avian pathogenic E. coli strain belonging to the serogroup O78. PMID:23516182

Pathogenic Potential to Humans of Bovine Escherichia coli O26, Scotland

PubMed Central

Rosser, Tracy; Allison, Lesley J.; Courcier, Emily; Evans, Judith; McKendrick, Iain J.; Pearce, Michael C.; Handel, Ian; Caprioli, Alfredo; Karch, Helge; Hanson, Mary F.; Pollock, Kevin G.J.; Locking, Mary E.; Woolhouse, Mark E.J.; Matthews, Louise; Low, J. Chris; Gally, David L.

2012-01-01

Escherichia coli O26 and O157 have similar overall prevalences in cattle in Scotland, but in humans, Shiga toxin–producing E. coli O26 infections are fewer and clinically less severe than E. coli O157 infections. To investigate this discrepancy, we genotyped E. coli O26 isolates from cattle and humans in Scotland and continental Europe. The genetic background of some strains from Scotland was closely related to that of strains causing severe infections in Europe. Nonmetric multidimensional scaling found an association between hemolytic uremic syndrome (HUS) and multilocus sequence type 21 strains and confirmed the role of stx2 in severe human disease. Although the prevalences of E. coli O26 and O157 on cattle farms in Scotland are equivalent, prevalence of more virulent strains is low, reducing human infection risk. However, new data on E. coli O26–associated HUS in humans highlight the need for surveillance of non-O157 enterohemorrhagic E. coli and for understanding stx2 phage acquisition. PMID:22377426

Physicochemical factors influencing the preferential transport of Escherichia coli in soils

USDA-ARS?s Scientific Manuscript database

Laboratory and numerical studies were conducted to investigate the transport and release of Escherichia coli D21g in preferential flow systems with artificial macropores under different ionic strength (IS) conditions. Macropores were created by embedding coarse sand lenses in a fine sand matrix and ...

Study of the effects of high-energy proton beams on escherichia coli

NASA Astrophysics Data System (ADS)

Park, Jeong Chan; Jung, Myung-Hwan

2015-10-01

Antibiotic-resistant bacterial infection is one of the most serious risks to public health care today. However, discouragingly, the development of new antibiotics has progressed little over the last decade. There is an urgent need for alternative approaches to treat antibiotic-resistant bacteria. Novel methods, which include photothermal therapy based on gold nano-materials and ionizing radiation such as X-rays and gamma rays, have been reported. Studies of the effects of high-energy proton radiation on bacteria have mainly focused on Bacillus species and its spores. The effect of proton beams on Escherichia coli (E. coli) has been limitedly reported. Escherichia coli is an important biological tool to obtain metabolic and genetic information and is a common model microorganism for studying toxicity and antimicrobial activity. In addition, E. coli is a common bacterium in the intestinal tract of mammals. In this research, the morphological and the physiological changes of E. coli after proton irradiation were investigated. Diluted solutions of cells were used for proton beam radiation. LB agar plates were used to count the number of colonies formed. The growth profile of the cells was monitored by using the optical density at 600 nm. The morphology of the irradiated cells was observed with an optical microscope. A microarray analysis was performed to examine the gene expression changes between irradiated samples and control samples without irradiation. E coli cells have observed to be elongated after proton irradiation with doses ranging from 13 to 93 Gy. Twenty-two were up-regulated more than twofold in proton-irradiated samples (93 Gy) compared with unexposed one.

Biofilm-Forming Abilities of Shiga Toxin-Producing Escherichia coli Isolates Associated with Human Infections

PubMed Central

Vogeleer, Philippe; Tremblay, Yannick D. N.; Jubelin, Grégory; Jacques, Mario

2015-01-01

Forming biofilms may be a survival strategy of Shiga toxin-producing Escherichia coli to enable it to persist in the environment and the food industry. Here, we evaluate and characterize the biofilm-forming ability of 39 isolates of Shiga toxin-producing Escherichia coli isolates recovered from human infection and belonging to seropathotypes A, B, or C. The presence and/or production of biofilm factors such as curli, cellulose, autotransporter, and fimbriae were investigated. The polymeric matrix of these biofilms was analyzed by confocal microscopy and by enzymatic digestion. Cell viability and matrix integrity were examined after sanitizer treatments. Isolates of the seropathotype A (O157:H7 and O157:NM), which have the highest relative incidence of human infection, had a greater ability to form biofilms than isolates of seropathotype B or C. Seropathotype A isolates were unique in their ability to produce cellulose and poly-N-acetylglucosamine. The integrity of the biofilms was dependent on proteins. Two autotransporter genes, ehaB and espP, and two fimbrial genes, z1538 and lpf2, were identified as potential genetic determinants for biofilm formation. Interestingly, the ability of several isolates from seropathotype A to form biofilms was associated with their ability to agglutinate yeast in a mannose-independent manner. We consider this an unidentified biofilm-associated factor produced by those isolates. Treatment with sanitizers reduced the viability of Shiga toxin-producing Escherichia coli but did not completely remove the biofilm matrix. Overall, our data indicate that biofilm formation could contribute to the persistence of Shiga toxin-producing Escherichia coli and specifically seropathotype A isolates in the environment. PMID:26712549

Biofilm-Forming Abilities of Shiga Toxin-Producing Escherichia coli Isolates Associated with Human Infections.

PubMed

Vogeleer, Philippe; Tremblay, Yannick D N; Jubelin, Grégory; Jacques, Mario; Harel, Josée

2015-12-28

Forming biofilms may be a survival strategy of Shiga toxin-producing Escherichia coli to enable it to persist in the environment and the food industry. Here, we evaluate and characterize the biofilm-forming ability of 39 isolates of Shiga toxin-producing Escherichia coli isolates recovered from human infection and belonging to seropathotypes A, B, or C. The presence and/or production of biofilm factors such as curli, cellulose, autotransporter, and fimbriae were investigated. The polymeric matrix of these biofilms was analyzed by confocal microscopy and by enzymatic digestion. Cell viability and matrix integrity were examined after sanitizer treatments. Isolates of the seropathotype A (O157:H7 and O157:NM), which have the highest relative incidence of human infection, had a greater ability to form biofilms than isolates of seropathotype B or C. Seropathotype A isolates were unique in their ability to produce cellulose and poly-N-acetylglucosamine. The integrity of the biofilms was dependent on proteins. Two autotransporter genes, ehaB and espP, and two fimbrial genes, z1538 and lpf2, were identified as potential genetic determinants for biofilm formation. Interestingly, the ability of several isolates from seropathotype A to form biofilms was associated with their ability to agglutinate yeast in a mannose-independent manner. We consider this an unidentified biofilm-associated factor produced by those isolates. Treatment with sanitizers reduced the viability of Shiga toxin-producing Escherichia coli but did not completely remove the biofilm matrix. Overall, our data indicate that biofilm formation could contribute to the persistence of Shiga toxin-producing Escherichia coli and specifically seropathotype A isolates in the environment. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Thermal inactivation of Escherichia coli 0157:H7 (ECOH) and non-0157 Shiga toxin-producing E.coli (STEC)in mechanically tenderized veal

USDA-ARS?s Scientific Manuscript database

We quantified thermal destruction of Shiga toxin-producing Escherichia coli O157:H7 (ECOH) and Shiga toxin-producing non-O157 E. coli (STEC) cells within mechanically tenderized veal cutlets following cooking on an electric skillet. For each of five trials, flattened veal cutlets (ca. 71.6 g; ca. 1/...

Prevalence, antimicrobial resistance and virulence genes in Escherichia coli isolated from retail meats in Tamaulipas, México.

PubMed

Martínez-Vázquez, Ana Verónica; Rivera-Sánchez, Gildardo; Lira Méndez, Krystal; Reyes-López, Miguel Ángel; Bocanegra-García, Virgilio

2018-02-28

The aim of this work was to determinate the prevalence of Escherichia coli and its resistance to antimicrobials and the presence of virulence genes in retail samples of beef and pork in several locations in Tamaulipas. In this work, a total of 106 samples (beef and pork) collected from August 2013 to March 2014, were analyzed to detect Escherichia coli and then analyzed for virulence, antibiotic resistance gene detection, and tested for susceptibility to 16 antimicrobials. One hundred fifty-eight Escherichia coli isolates were obtained and of these, 1.8% harbored stx1; stx2 and hlyA was detected in 17.7% and 21.5% of isolates, respectively. High-resistance phenotypes were observed in almost all of the isolates since 92.4% showed a multi-resistant phenotype with resistance to cephalothin 92%, ampicillin 92%, cefotaxime 78%, nitrofurantoin 76% and tetracycline 75%. tetA and tetB were detected in 56% of isolates, strA in 9.6%, aadA in 17%, and aac(3)-IV in only 0.6% of strains. Based on these results, it can be concluded that retail beef and pork meat, might play a role in the spread of antibiotic resistant Escherichia coli strains in our region. Copyright © 2018. Published by Elsevier Ltd.

Proliferation of Escherichia coli O157:H7 in soil and hydroponic microgreen production systems

USDA-ARS?s Scientific Manuscript database

Radish (Raphanus sativus var. longipinnatus) microgreens were produced from seeds inoculated with Escherichia coli O157: H7 using soil substitute and hydroponic production systems. E. coli populations on the edible and inedible parts of harvested microgreen plants and in growth medium were examined....

Detection of intracellular bacterial communities in a child with Escherichia coli recurrent urinary tract infections.

PubMed

Robino, Luciana; Scavone, Paola; Araujo, Lucia; Algorta, Gabriela; Zunino, Pablo; Vignoli, Rafael

2013-08-01

The formation of intracellular bacterial communities (IBC) has been proposed as a new pathogenic model for urinary tract infections. Scarce reports describe this phenomenon in humans. We describe the presence of IBC in uroepithelial cells of a child with recurrent urinary infections. Urine specimen was collected from a child with Escherichia coli UTI and analyzed by light and confocal laser scanning microscopy (CLSM). The capability of this strain to produce intracellular infection in bladder tissue was confirmed in mice models. Escherichia coli phylogenetic group, presence of virulence factors genes, and its multiple locus sequence type were determined. CLSM showed large collections of morphologically coccoid and rod bacteria in eukaryotic cells cytoplasm, even seemingly protruding from the cells. Escherichia coli EC7U, ST3626, harbored type 1, P, and S/F1C fimbriae and K1 capsule genes. In this report, we confirm the presence of IBC in children with UTI, as it has been described before in women. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

ROS mediated selection for increased NADPH availability in Escherichia coli.

PubMed

Reynolds, Thomas S; Courtney, Colleen M; Erickson, Keesha E; Wolfe, Lisa M; Chatterjee, Anushree; Nagpal, Prashant; Gill, Ryan T

2017-11-01

The economical production of chemicals and fuels by microbial processes remains an intense area of interest in biotechnology. A key limitation in such efforts concerns the availability of key co-factors, in this case NADPH, required for target pathways. Many of the strategies pursued for increasing NADPH availability in Escherichia coli involve manipulations to the central metabolism, which can create redox imbalances and overall growth defects. In this study we used a reactive oxygen species based selection to search for novel methods of increasing NADPH availability. We report a loss of function mutation in the gene hdfR appears to increase NADPH availability in E. coli. Additionally, we show this excess NADPH can be used to improve the production of 3HP in E. coli. © 2017 Wiley Periodicals, Inc.

Elimination of Escherichia coli and Salmonella in Clam by Using Zeolite in a Station of Depuration.

PubMed

Gdoura, Morsi; Sellami, Hanen; Khannous, Lamia; Ketata, Najib; Neila, Idriss Ben; Traore, Al Ibrahim; Chekir, Zouhair; Gdoura, Radhouane

2017-09-01

  The application of natural zeolite for water and wastewater treatment has been carried out and is still a promising technique in environmental cleaning processes. Natural zeolite can be used to improve the purification process of clams (Ruditapes decussatus). Thus, our study aimed at improving the clam purification system in order to reduce Escherichia coli and eliminate Salmonella in samples artificially contaminated with this bacterium using a natural zeolite to replace the biological filter. The results showed that zeolite used in a depuration system improved the clam purification process. Moreover, natural zeolite exhibited high performance in the adsorption of bacteria and allowed to reduce the Escherichia coli abundance in 24 h, thus ensuring purified clams conformity with the ISO 16649-3 standard. These results indicate the beneficial effects of using zeolite in the adsorption of bacteria and the reduction in the abundance of Escherichia coli and set the Salmonella from marine organisms.

The isolation of Escherichia coli from a poultry packing station and an abattoir

PubMed Central

Shooter, R. A.; Cooke, E. Mary; O'Farrell, Sheila; Bettelheim, K. A.; Chandler, Mary E.; Bushrod, Frances M.

1974-01-01

The distribution and serotype of strains of Escherichia coli from a poultry packing station and an abattoir are described. The results indicated that animal faecal strains contaminated the environment and the animal carcasses. Using 150 O antisera, a high proportion of the E. coli strains were non-typable. This suggests that the serotype distribution of E. coli in animals is different from that in man. Strains with single antigenic differences were isolated, and the possibility of genetic transfer of these antigenic structures is suggested. PMID:4608415

[The antibacterial activity of oregano essential oil (Origanum heracleoticum L.) against clinical strains of Escherichia coli and Pseudomonas aeruginosa].

PubMed

Sienkiewicz, Monika; Wasiela, Małgorzata; Głowacka, Anna

2012-01-01

The aim of this study was to investigate the antibacterial properties of oregano (Origanum heracleoticum L.) essential oil against clinical strains of Escherichia coli and Pseudomonas aeruginosa. The antibacterial activity of oregano essential oil was investigate against 2 tested and 20 clinical bacterial strains of Escherichia coli and 20 clinical strains o Pseudomonas aeruginosa come from patients with different clinical conditions. The agar dilution method was used for microbial growth inhibition at various concentrations ofoil. Susceptibility testing to antibiotics was carried out using disc-diffusion method. The results of experiments showed that the tested oil was active against all of the clinical strains from both genus of bacteria, but strains of Escherichia coli were more sensitive to tested oil. Essential oil from Origanum heracleoticum L. inhibited the growth of Escherichia coli and Pseudomonas aeruginosa clinical strains with different patters of resistance. The obtained outcomes will enable further investigations using oregano essential oil obtained from Origanum heracleoticum L. as alternative antibacterial remedies enhancing healing process in bacterial infections and as an effective means for the prevention of antibiotic-resistant strain development.

[Asymptomatic bacteriuria in pregnancy].

PubMed

Caputo, S; Ciardo, A

2001-01-01

Pregnancy is a predisposing factor for urinary tract infection and pregnant women suffering from this pathology are exposed to dangerous risks which may condition maternal wellbeing and fetal prognosis. Asymptomatic bacteriuria is the common bacterial infection requiring medical treatment in pregnancy. Diagnosis and treatment of asymptomatic bacteriuria is important as approximately 20-40% of these women, if untreated during pregnancy, will develop a symptomatic urinary tract infection.

Biorecognition of Escherichia coli K88 adhesin for glycated porcine albumin.

PubMed

Sarabia-Sainz, Andre-i; Ramos-Clamont, Gabriela; Candia-Plata, Ma María del Carmen; Vázquez-Moreno, Luz

2009-03-01

Escherichia coli (E. coli) that expresses galactose-reactive lectins, like K88 adhesin, causes high mortality among piglets. Carbohydrates that compete for adhesion could serve as an alternative for disease prevention. Porcine serum albumin (PSA) was modified by non-enzymatic glycation with lactose to produce PSA-Lac or PSA-Glc beta (1-4) Gal, as confirmed by reduction of available free amino groups, increased molecular mass and by Ricinus communis lectin recognition. E. coli K88 binds to PSA-Lac treatments containing three and four lactoses, respectively. In addition, PSA-Lac partially inhibited K88 strain adherence to mucins. These results suggest that neoglycoconjugates obtained by non-enzymatic glycation of proteins may serve in the prophylaxis of piglets' diarrhea.

[Application of DNA-based electrochemical biosensor in rapid detection of Escherichia coli exist in licorice decoction].

PubMed

Zhao, Yu-Wen; Wang, Hai-Xia; Bie, Song-Tao; Shao, Qian; Wang, Chun-Hua; Wang, Dong-Heng; Li, Zheng

2018-03-01

A new method for detection of Escherichia coli exist in licorice decoction was developed by using DNA-based electrochemical biosensor. The thiolated capture probe was immobilized on a gold electrode at first. Then the aptamer for Escherichia coli was combined with the capture probe by hybridization. Due to the stronger interaction between the aptamer and the E. coli, the aptamer can dissociate from the capture probe in the presence of E. coli in licorice decoction. The biotinylated detection probe was hybridized with the single-strand capture probe. As a result, the electrochemical response to Escherichia coli can be measured by using differential pulse voltammetric in the presence of α-naphthyl phosphate. The plot of peak current vs. the logarithm of concentration in the range from 2.7×10² to 2.7×10⁸ CFU·mL⁻¹ displayed a linear relationship with a detection limit of 50 CFU·mL⁻¹. The relative standard deviation of 3 successive scans was 2.5%，2.1%，4.6% for 2×10²，2×10⁴，2×106：⁶ CFU·mL⁻¹ E. coli, respectively. The proposed procedure showed better specificity to E. coli in comparison to Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis. In the detection of the real extractum glycyrrhizae, the results between the proposed strategy and the GB assay showed high degree of agreement, demonstrating the designed biosensor could be utilized as a powerful tool for microbial examination for traditional Chinese medicine. Copyright© by the Chinese Pharmaceutical Association.

Bactericidal Effect of Zero-Valent Iron Nanoparticles on Escherichia coli

PubMed Central

Lee, Changha; Kim, Jee Yeon; Lee, Won Il; Nelson, Kara L.; Yoon, Jeyong; Sedlak, David L.

2008-01-01

Zero-valent iron nanoparticles (nano-Fe0) in aqueous solution rapidly inactivated Escherichia coli (E. coli). A strong bactericidal effect of nano-Fe0 was found under deaerated conditions, with a linear correlation between log inactivation and nano-Fe0 dose (0.82 log inactivation / mg/L nano-Fe0 · hr). The inactivation of E. coli under air saturation required much higher nano-Fe0 doses due to the corrosion and surface oxidation of nano-Fe0 by dissolved oxygen. Significant physical disruption of the cell membranes was observed in E. coli exposed to nano-Fe0, which may have caused the inactivation, or enhanced the biocidal effects of dissolved iron. The reaction of Fe(II) with intracellular oxygen or hydrogen peroxide also may have induced oxidative stress by producing reactive oxygen species. The bactericidal effect of nano-Fe0 was a unique property of nano-Fe0, which was not observed in other types of iron-based compounds. PMID:18678028

Copper import in Escherichia coli by the yersiniabactin metallophore system

PubMed Central

Koh, Eun-Ik; Robinson, Anne E.; Bandara, Nilantha; Rogers, Buck E.; Henderson, Jeffrey P.

2017-01-01

Copper plays a dual role as nutrient and toxin during bacterial infections. While uropathogenic Escherichia coli (UPEC) strains can use the copper-binding metallophore yersiniabactin (Ybt) to resist copper toxicity, Ybt also converts bioavailable copper to Cu(II)-Ybt in low copper conditions. Although E. coli have long been considered to lack a copper import pathway, we observed Ybt-mediated copper import in UPEC using canonical Fe(III)-Ybt transport proteins. UPEC removed copper from Cu(II)-Ybt with subsequent re-export of metal-free Ybt to the extracellular space. Copper released through this process became available to an E. coli cuproenzyme (the amine oxidase TynA), linking this import pathway to a nutrient acquisition function. Ybt-expressing E. coli thus engage in nutritional passivation, a strategy of minimizing a metal ion's toxicity while preserving its nutritional availability. Copper acquisition through this process may contribute to the marked virulence defect of Ybt transport-deficient UPEC. PMID:28759019

Escherichia coli early-onset sepsis: trends over two decades.

PubMed

Mendoza-Palomar, Natalia; Balasch-Carulla, Milena; González-Di Lauro, Sabina; Céspedes, Maria Concepció; Andreu, Antònia; Frick, Marie Antoinette; Linde, Maria Ángeles; Soler-Palacin, Pere

2017-09-01

Escherichia coli early-onset sepsis (EOS) is an important cause of mortality and morbidity in neonates, especially in preterm and very low birth weight (VLBW) newborns. The aim of our study was to evaluate potential changes in the clinical and microbiological characteristics of E. coli EOS in our setting. Epidemiological, clinical, and microbiological data from all neonates with proven E. coli EOS from January 1994 to December 2014 were retrospectively collected in a single tertiary care hospital in Barcelona (Spain). Seventy-eight E. coli EOS cases were analyzed. A slight increase in the incidence of E. coli EOS was observed during the study period. VLBW newborns remained the group with higher incidence (10.4 cases per 1000 live births) and mortality (35.3%). Systematic use of PCR increased E. coli EOS diagnosis, mainly in the term newborn group. There was an increase in resistant E. coli strains causing EOS, with especially high resistance to ampicillin and gentamicin (92.8 and 28.6%, respectively). Nonetheless, resistant strains were not associated with poorer clinical outcomes. There is an urgent need to reconsider the empirical therapy used in neonatal EOS, particularly in VLBW newborns. What is Known: • E. coli early-onset sepsis (EOS) and E. coli resistant strains have been described as overall stable but increasing in VLBW neonates (< 1.500 g) in previous studies. What is New: • Our study shows an increasing incidence of E. coli EOS in all age groups, overruling group B Streptoccocus for the last 10 years. E. coli resistant strains also increased equally in all age groups, with high resistance rates to our first line antibiotics (ampicillin and gentamicin). • Empiric antibiotic therapy of EOS, mainly in VLBW newborns, should be adapted to this new scenario.

Photonic Characteristics and Ex Vivo Imaging of Escherichia coli-Xen14 Within the Bovine Reproductive Tract

USDA-ARS?s Scientific Manuscript database

The objectives of this study were to (1) characterize the photonic properties of Escherichia coli-Xen14 and (2) conduct photonic imaging of E. coli-Xen14 within bovine reproductive tract segments (RTS) ex vivo (Bos indicus). E. coli-Xen14 was grown for 24 h in Luria Bertani medium (LB), with or with...

Single Multiplex PCR Assay To Identify Simultaneously the Six Categories of Diarrheagenic Escherichia coli Associated with Enteric Infections

PubMed Central

Vidal, Maricel; Kruger, Eileen; Durán, Claudia; Lagos, Rosanna; Levine, Myron; Prado, Valeria; Toro, Cecilia; Vidal, Roberto

2005-01-01

We designed a multiplex PCR for the detection of all categories of diarrheagenic Escherichia coli. This method proved to be specific and rapid in detecting virulence genes from Shiga toxin-producing (stx1, stx2, and eae), enteropathogenic (eae and bfp), enterotoxigenic (stII and lt), enteroinvasive (virF and ipaH), enteroaggregative (aafII), and diffuse adherent (daaE) Escherichia coli in stool samples. PMID:16208019

Pseudomonas aeruginosa Promotes Escherichia coli Biofilm Formation in Nutrient-Limited Medium

PubMed Central

Culotti, Alessandro; Packman, Aaron I.

2014-01-01

Biofilms have been implicated as an important reservoir for pathogens and commensal enteric bacteria such as Escherichia coli in natural and engineered water systems. However, the processes that regulate the survival of E. coli in aquatic biofilms have not been thoroughly studied. We examined the effects of hydrodynamic shear and nutrient concentrations on E. coli colonization of pre-established Pseudomonas aeruginosa biofilms, co-inoculation of E. coli and P. aeruginosa biofilms, and P. aeruginosa colonization of pre-established E. coli biofilms. In nutritionally-limited R2A medium, E. coli dominated biofilms when co-inoculated with P. aeruginosa, and successfully colonized and overgrew pre-established P. aeruginosa biofilms. In more enriched media, P. aeruginosa formed larger clusters, but E. coli still extensively overgrew and colonized the interior of P. aeruginosa clusters. In mono-culture, E. coli formed sparse and discontinuous biofilms. After P. aeruginosa was introduced to these biofilms, E. coli growth increased substantially, resulting in patterns of biofilm colonization similar to those observed under other sequences of organism introduction, i.e., E. coli overgrew P. aeruginosa and colonized the interior of P. aeruginosa clusters. These results demonstrate that E. coli not only persists in aquatic biofilms under depleted nutritional conditions, but interactions with P. aeruginosa can greatly increase E. coli growth in biofilms under these experimental conditions. PMID:25198725

Enteropathogenic Escherichia coli (EPEC) infection in association with acute gastroenteritis in 7 dogs from Saskatchewan

PubMed Central

Kjaergaard, Astrid B.; Carr, Anthony P.; Gaunt, M. Casey

2016-01-01

Seven dogs diagnosed with enteropathogenic Escherichia coli (EPEC) infection in association with acute gastroenteritis are described. Disease severity ranged from mild in adults to fatal disease in young dogs. Enteropathogenic E. coli infection should be considered as a possible differential diagnosis in dogs with diarrhea. PMID:27587889

Effects of intravenous Escherichia coli dose on the pathophysiological response of colostrum-fed Jersey calves

USDA-ARS?s Scientific Manuscript database

Objectives of the present study were to characterize the dose dependency of an intravenous Escherichia coli (E. coli) challenge in colostrum-fed Jersey calves and to identify biochemical markers indicative of septicemia. Eighteen 3-wk old colostrum-fed Jersey calves were completely randomized to 1 o...

Plastic Encapsulation of Stabilized Escherichia coli and Pseudomonas putida

PubMed Central

Manzanera, M.; Vilchez, S.; Tunnacliffe, A.

2004-01-01

Escherichia coli and Pseudomonas putida dried in hydroxyectoine or trehalose are shown to be highly resistant to the organic solvents chloroform and acetone, and consequently, they can be encapsulated in a viable form in solid plastic materials. Bacteria are recovered by rehydration after physical disruption of the plastic. P. putida incorporated into a plastic coating of maize seeds was shown to colonize roots efficiently after germination. PMID:15128579

Antibiotics for asymptomatic bacteriuria in pregnancy.

PubMed

Smaill, F

2000-01-01

Up to 30% of mothers develop acute pyelonephritis if asymptomatic bacteriuria is untreated. Asymptomatic bacteriuria may have a role in preterm birth, or it may be a marker for low socioeconomic status and thus, low birth weight. The objective of this review was to assess the effect of antibiotic treatment for asymptomatic bacteriuria on persistent bacteriuria during pregnancy, the risk of preterm delivery and the development of pyelonephritis after delivery. I searched the Cochrane Pregnancy and Childbirth Group trials register. Randomised trials comparing antibiotic treatment with placebo or no treatment in pregnant women with asymptomatic bacteriuria found on antenatal screening. Trial quality was assessed. Thirteen studies were included. Overall the study quality was not strong. Antibiotic treatment compared to placebo or no treatment was effective in clearing asymptomatic bacteriuria (odds ratio 0.07, 95% confidence interval 0.05 to 0.10). The incidence of pyelonephritis was reduced (odds ratio 0.25, 95% confidence interval 0.19 to 0.32). Antibiotic treatment was also associated with a reduction in the incidence of preterm delivery or low birth weight babies (odds ratio 0.60, 95% confidence interval 0.45 to 0.80). Antibiotic treatment appears to be effective in reducing the risk of pyelonephritis in pregnancy. An apparent reduction in preterm delivery is consistent with current theories about the role of infection in preterm birth, but this association should be interpreted with caution.

The Detection Method of Escherichia coli in Water Resources: A Review

NASA Astrophysics Data System (ADS)

Nurliyana, M. R.; Sahdan, M. Z.; Wibowo, K. M.; Muslihati, A.; Saim, H.; Ahmad, S. A.; Sari, Y.; Mansor, Z.

2018-04-01

This article reviews several approaches for Escherichia coli (E. coli) bacteria detection from conventional methods, emerging method and goes to biosensor-based techniques. Detection and enumeration of E. coli bacteria usually required long duration of time in obtaining the result since laboratory-based approach is normally used in its assessment. It requires 24 hours to 72 hours after sampling to process the culturing samples before results are available. Although faster technique for detecting E. coli in water such as Polymerase Chain Reaction (PCR) and Enzyme-Linked Immunosorbent Assay (ELISA) have been developed, it still required transporting the samples from water resources to the laboratory, high-cost, complicated equipment usage, complex procedures, as well as the requirement of skilled specialist to cope with the complexity which limit their wide spread practice in water quality detection. Recently, development of biosensor device that is easy to perform, portable, highly sensitive and selective becomes indispensable in detecting extremely lower consolidation of pathogenic E. coli bacteria in water samples.

Molecular epidemiology of Escherichia coli mediated urinary tract infections.

PubMed

Zhang, Lixin; Foxman, Betsy

2003-01-01

Urinary tract infection (UTI) is one of the most frequently acquired bacterial infections and Escherichia coli accounts for as many as 90% of all UTIs seen among ambulatory populations. Risk factors for UTIs include host behaviors, host characteristics and bacterial characteristics. Sexual activity and contraceptive method are the strongest determinant of a symptomatic UTI episode. The characteristics of cell receptors, anatomical differences and genetic predisposition in the host may be important determinants of increased risk for recurrent infections. Uropathogenic E. coli have special characteristics causing urovirulence. They most likely belong to phylogenic lineage B2. They usually possess specific adhesins such as P, S or Dr to facilitate their colonization in the urinary tract, and toxins such as hemolysin and cytotoxic necrotizing factor 1 to provoke inflammatory response that possibly are responsible for the development of UTI symptoms. Interestingly, virulence genes in uropathogenic E. coli are often co-located on pathogenicity islands. Currently, however, none of the known virulence genes or set of genes can clearly define the prototypic uropathogenic E. coli. Additional studies are needed to identify factors that promote uropathogen transmission and persistent colonization, and to investigate potential different modes of pathogenesis by E. coli strains with different compositions of virulence genes.

Isolation, genotyping, and antimicrobial resistance of zoonotic shiga toxin-producing escherichia coli

USDA-ARS?s Scientific Manuscript database

Shiga toxin-producing Escherichia coli (STEC) is an enteric pathogen linked to outbreaks of human gastroenteritis with diverse clinical spectra. Traditional culture and isolation methods, including selective enrichment and differential plating, have enabled the effective recovery of STEC. Ruminants ...

Enterohemorrhagic Escherichia coli O157:H7 present in radish sprouts.

PubMed

Itoh, Y; Sugita-Konishi, Y; Kasuga, F; Iwaki, M; Hara-Kudo, Y; Saito, N; Noguchi, Y; Konuma, H; Kumagai, S

1998-04-01

Using cultivation, immunofluorescence microscopy, and scanning electron microscopy, we demonstrated the presence of viable enterohemorrhagic Escherichia coli O157:H7 not only on the outer surfaces but also in the inner tissues and stomata of cotyledons of radish sprouts grown from seeds experimentally contaminated with the bacterium. HgCl2 treatment of the outer surface of the hypocotyl did not kill the contaminating bacteria, which emphasized the importance of either using seeds free from E. coli O157:H7 in the production of radish sprouts or heating the sprouts before they are eaten.

TRYPTOPHAN SYNTHETASE LEVELS IN ESCHERICHIA COLI, SHIGELLA DYSENTERIAE, AND TRANSDUCTION HYBRIDS

PubMed Central

Eisenstein, Richard B.; Yanofsky, Charles

1962-01-01

Eisenstein, Richard B. (Western Reserve University, Cleveland, Ohio) and Charles Yanofsky. Tryptophan synthetase levels in Escherichia coli, Shigella dysenteriae, and transduction hybrids. J. Bacteriol. 83:193–204. 1962—Shigella dysenteriae and Escherichia coli, strains K-12 and B, were found to produce low levels of tryptophan synthetase, although some hybrids, formed by the introduction of the gene cluster concerned with tryptophan synthesis from S. dysenteriae into E. coli, produced high levels of this enzyme system. A revertant obtained from a tryptophan-requiring mutant also formed high levels of tryptophan synthetase. The gene or genes responsible for high enzyme production in these strains was shown to be linked to the cluster of genes concerned with tryptophan synthesis. The cause of high enzyme production was investigated. Various lines of evidence, including stimulation of growth by tryptophan precursors, sensitivity to inhibition by 5-methyltryptophan, absence of accumulation of tryptophan, and repression of enzyme formation by anthranilic acid and tryptophan, suggested that high enzyme production in the strains examined results from a partial block in the tryptophan pathway and not from resistance to repression by tryptophan. The conversion of shikimic acid-5-phosphate to anthranilic acid appears to be the partially blocked reaction in the strains studied. PMID:13889700

Enumeration of Escherichia coli O157:H7 in Outbreak-Associated Beef Patties.

PubMed

Gill, Alexander; Huszczynski, George

2016-07-01

An outbreak of five cases of Escherichia coli O157 infection that occurred in Canada in 2012 was linked to frozen beef patties seasoned with garlic and peppercorn. Unopened retail packs of beef patties from the implicated production lot were recovered and analyzed to enumerate E. coli O157, other E. coli strains, and total coliforms. E. coli O157 was not recovered by direct enumeration on selective agar media. E. coli O157 in the samples was estimated at 3.1 most probable number per 140 g of beef patty, other E. coli was 11 CFU/g, and coliforms were 120 CFU/g. These results indicate that the presence of E. coli O157 in ground beef at levels below 0.1 CFU/g may cause outbreaks. However, the roles of temperature abuse, undercooking, and crosscontamination in amplifying the risk are unknown.

The binary protein-protein interaction landscape of Escherichia coli

PubMed Central

Rajagopala, Seesandra V.; Vlasblom, James; Arnold, Roland; Franca-Koh, Jonathan; Pakala, Suman B.; Phanse, Sadhna; Ceol, Arnaud; Häuser, Roman; Siszler, Gabriella; Wuchty, Stefan; Emili, Andrew; Babu, Mohan; Aloy, Patrick; Pieper, Rembert; Uetz, Peter

2014-01-01

Efforts to map the Escherichia coli interactome have identified several hundred macromolecular complexes, but direct binary protein-protein interactions (PPIs) have not been surveyed on a large scale. Here we performed yeast two-hybrid screens of 3,305 baits against 3,606 preys (~70% of the E. coli proteome) in duplicate to generate a map of 2,234 interactions, approximately doubling the number of known binary PPIs in E. coli. Integration of binary PPIs and genetic interactions revealed functional dependencies among components involved in cellular processes, including envelope integrity, flagellum assembly and protein quality control. Many of the binary interactions that could be mapped within multi-protein complexes were informative regarding internal topology and indicated that interactions within complexes are significantly more conserved than those interactions connecting different complexes. This resource will be useful for inferring bacterial gene function and provides a draft reference of the basic physical wiring network of this evolutionarily significant model microbe. PMID:24561554

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

PubMed

Jørgensen, Steffen L; Kudirkiene, Egle; Li, Lili; Christensen, Jens P; Olsen, John E; Nolan, Lisa; Olsen, Rikke H

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 economy and welfare worldwide. An almost defining characteristic of avian pathogenic E. coli is the carriage of plasmids, which may encode virulence factors and antibiotic resistance determinates. For the same reason, plasmids of avian pathogenic E. coli have been intensively studied. However, genes encoded by the chromosome may also be important for disease manifestation and antimicrobial resistance. For the E. coli strain APEC_O2 the plasmids have been sequenced and analyzed in several studies, and E. coli APEC_O2 may therefore serve as a reference strain in future studies. Here we describe the chromosomal features of E. coli APEC_O2. E. coli APEC_O2 is a sequence type ST135, has a chromosome of 4,908,820 bp (plasmid removed), comprising 4672 protein-coding genes, 110 RNA genes, and 156 pseudogenes, with an average G + C content of 50.69%. We identified 82 insertion sequences as well as 4672 protein coding sequences, 12 predicated genomic islands, three prophage-related sequences, and two clustered regularly interspaced short palindromic repeats regions on the chromosome, suggesting the possible occurrence of horizontal gene transfer in this strain. The wildtype strain of E. coli APEC_O2 is resistant towards multiple antimicrobials, however, no (complete) antibiotic resistance genes were present on the chromosome, but a number of genes associated with extra-intestinal disease were identified. Together, the information provided here on E. coli APEC_O2 will assist in future studies of avian pathogenic E. coli strains, in particular regarding strain of E. coli APEC_O2, and aid in the general understanding of the pathogenesis of avian pathogenic E. coli .

Genetic Control of the Secondary Modification of Deoxyribonucleic Acid in Escherichia coli1

PubMed Central

Mamelak, Linda; Boyer, Herbert W.

1970-01-01

The wild-type restriction and modification alleles of Escherichia coli K-12 and B were found to have no measurable effect on the patterns of methylated bases in the deoxyribonucleic acid (DNA) of these strains. The genetic region controlling the methylation of cytosine in E. coli K-12 was mapped close to his, and the presence or absence of this gene in E. coli B or E. coli K had no effect on the restriction and modification properties of these strains. Thus, only a few of the methylated bases in the DNA of these strains are involved in host modification, and the biological role of the remainder remains obscure. PMID:4919756

Regulation of Biofilm Formation in Escherichia coli O157:H7

USDA-ARS?s Scientific Manuscript database

Escherichia coli O157:H7 encodes a variety of genetic factors for adherence to epithelial cells and to abiotic surfaces. While adherence to epithelial cells culminates in the formation of characteristic attaching and effacing (A/E) lesions, adherence to abiotic surfaces represents a prelude to the f...

Ex Vivo Bioluminescence Imaging of Late Gestation Ewes Following Intra-uterine Inoculation With Lux-modified Escherichia coli

USDA-ARS?s Scientific Manuscript database

Our objectives were to develop an ovine model for Escherichia coli-induced preterm delivery, and monitor E. coli (lux modified for photonic detection) invasion of the fetal environment—ewes (124 ± 18 d of gestation) received intrauterine inoculations using E. coli-lux as follows: control (n = 5), 1....

Disruption the Outer Membrane of Enteropathogenic and Enterotoxigenic Escherichia coli using Proanthocyanidins

USDA-ARS?s Scientific Manuscript database

American cranberry (Vaccinium macrocarpon) proanthocyanidins (PACs) have been reported as a natural antibacterial agent to suppress the growth of pathogenic Escherichia coli. The objective of this study was to investigate the efficacy of cranberry-derived proanthocyanidins on destabilizing the outer...

Genome sequences of Escherichia coli strains that cause persistent and transient mastitis

USDA-ARS?s Scientific Manuscript database

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....

Draft genomic sequencing of six potential extraintestinal pathogenic Escherichia coli isolates from retail chicken meat.

USDA-ARS?s Scientific Manuscript database

Potential Extraintestinal pathogenic Escherichia coli isolates DP254, WH333, WH398, F356, FEX675 and FEX725 were isolated from retail chicken meat products. Here, we report the draft genome sequences for these six E. coli isolates, which are currently being used in food safety research....

Human MAIT-cell responses to Escherichia coli: activation, cytokine production, proliferation, and cytotoxicity.

PubMed

Dias, Joana; Sobkowiak, Michał J; Sandberg, Johan K; Leeansyah, Edwin

2016-07-01

Mucosa-associated invariant T cells are a large and relatively recently described innate-like antimicrobial T-cell subset in humans. These cells recognize riboflavin metabolites from a range of microbes presented by evolutionarily conserved major histocompatibility complex, class I-related molecules. Given the innate-like characteristics of mucosa-associated invariant T cells and the novel type of antigens they recognize, new methodology must be developed and existing methods refined to allow comprehensive studies of their role in human immune defense against microbial infection. In this study, we established protocols to examine a range of mucosa-associated invariant T-cell functions as they respond to antigen produced by Escherichia coli These improved and dose- and time-optimized experimental protocols allow detailed studies of MR1-dependent mucosa-associated invariant T-cell responses to Escherichia coli pulsed antigen-presenting cells, as assessed by expression of activation markers and cytokines, by proliferation, and by induction of apoptosis and death in major histocompatibility complex, class I-related-expressing target cells. The novel and optimized protocols establish a framework of methods and open new possibilities to study mucosa-associated invariant T-cell immunobiology, using Escherichia coli as a model antigen. Furthermore, we propose that these robust experimental systems can also be adapted to study mucosa-associated invariant T-cell responses to other microbes and types of antigen-presenting cells. © The Author(s).

EFFECT OF VISIBLE RANGE ELECTROMAGNETIC RADIATIONS ON ESCHERICHIA COLI.

PubMed

Azeemi, Samina T Yousuf; Shaukat, Saleem Farooq; Azeemi, Khawaja Shamsuddin; Khan, Idrees; Mahmood, Khalid; Naz, Farah

2017-01-01

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 energy/vibrational medicine that uses visible spectrum of Electromagnetic Radiations to cure different diseases. In this study, our goal was to understand the effect of Visible Range Electromagnetic Radiations on E. coli (in vitro) and therefore find out the most appropriate visible range radiation for the treatment of diseases caused by E. coli. A total of 6 non-repetitive E. coli isolates were obtained from urine samples obtained from hospitalized patients with UTI. Single colony of E. coli was inoculated in 3 ml of Lysogeny Broth (LB) and 40 μl of this E. coli suspension was poured into each of the plastic tubes which were then irradiated with six different wavelengths in the visible region (Table. 1) after 18 hours with one acting as a control. The Optical Densities of these irradiated samples were then measured. Furthermore, scanning electron microscopy (TEFCAN ZEGA3) was carried out. The analysis of the microscopic and SEM images of irradiated E. coli samples with six different visible range radiations is representative of The fact that E. coli responded differently to every applied radiation in the visible region and the most profound inhibitory effects were that of 538nm Visible Range Radiation (Green) which proved to be bactericidal and 590nm Visible Range Radiation (yellow) which was bacteriostatic. The enhanced growth of E. coli with varying degrees was clearly observed in 610nm (orange), 644nm (red), 464nm (Purple) and 453nm (blue). It can be concluded that 538nm (Green) and 590nm (Yellow) can effectively be used for treating E. coli borne diseases.

EFFECT OF VISIBLE RANGE ELECTROMAGNETIC RADIATIONS ON ESCHERICHIA COLI

PubMed Central

Azeemi, Samina T. Yousuf; Shaukat, Saleem Farooq; Azeemi, Khawaja Shamsuddin; Khan, Idrees; Mahmood, Khalid; Naz, Farah

2017-01-01

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 energy/vibrational medicine that uses visible spectrum of Electromagnetic Radiations to cure different diseases. In this study, our goal was to understand the effect of Visible Range Electromagnetic Radiations on E. coli (in vitro) and therefore find out the most appropriate visible range radiation for the treatment of diseases caused by E. coli. Materials and Methods: A total of 6 non-repetitive E. coli isolates were obtained from urine samples obtained from hospitalized patients with UTI. Single colony of E. coli was inoculated in 3 ml of Lysogeny Broth (LB) and 40 μl of this E. coli suspension was poured into each of the plastic tubes which were then irradiated with six different wavelengths in the visible region (Table. 1) after 18 hours with one acting as a control. The Optical Densities of these irradiated samples were then measured. Furthermore, scanning electron microscopy (TEFCAN ZEGA3) was carried out. Results: The analysis of the microscopic and SEM images of irradiated E. coli samples with six different visible range radiations is representative of The fact that E. coli responded differently to every applied radiation in the visible region and the most profound inhibitory effects were that of 538nm Visible Range Radiation (Green) which proved to be bactericidal and 590nm Visible Range Radiation (yellow) which was bacteriostatic. The enhanced growth of E. coli with varying degrees was clearly observed in 610nm (orange), 644nm (red), 464nm (Purple) and 453nm (blue). Conclusion: It can be concluded that 538nm (Green) and 590nm (Yellow) can effectively be used for treating E. coli borne diseases. PMID:28331912

Persistence of Escherichia coli O157:H7 and total Escherichia coli in feces and feedlot surface manure from cattle fed diets with or without corn or sorghum wet distillers grains with solubles

USDA-ARS?s Scientific Manuscript database

Feeding corn wet distillers grains with solubles (WDGS) to cattle can increase the load of Escherichia coli O157:H7 in feces and on hides, but the mechanisms are not fully understood. The objective of these experiments was to examine a role for the persistence of E. coli O157:H7 in the feces and fee...

Pathological And Immunological Study On Infection With Escherichia Coli In ale BALB/c mice

NASA Astrophysics Data System (ADS)

Ali, Intisar H.; Jabir, Majid S.; Al-Shmgani, Hanady S. A.; Sulaiman, Ghassan M.; Sadoon, Ali H.

2018-05-01

Escherichia coli bacteria is considered as one of the common responsible for the frequency and severity of infections that it hospitalized patients. E. coli simultaneously carries a harmful side in which only a slight genetic recombination can bring about a highly pathogenic strain that most frequently causes the scourge of bacterial infections worldwide including sepsis, neonatal meningitis, pneumonia, bacteremia and traveler’s diarrhea. This study was carried out to assess Escherichia coli infection induced pathologically and immunologically. Following Escherichia coli isolation, identification and counting, the lethal dose (LD-50) was determined before infection. Twenty-two mice were used in this study for 21 days infection, the animals were sacrificed at 3, 6, 9, 12, 15, 18 and 21 days, and tissues of different tissue were collected, examined for bacterial infection. Bacteria and mice immunization and ELISA were used to detect immunoglobulin G level in serum as well. For histological study, different infected organs were used. The results indicated that the LH50 was 1×109 cell; and all organs were infected after 3 days followed by decreased in infection level shown in brain at day 12, lung, kidney and intestine at day 15 and in liver, spleen and heart at day 21. Moreover, ELISA results revealed that concentration 1:200 of serum in positive and negative state and optimum concentration of Ag 1:40 dilution and compact dilution is 1:1000. In addition, diversity of histopathological alteration occurs in tissue on time-depended manner. This study concluded that the ability of activated E.coli to stimulate the intestinal secretory immune system of germ might result from a retardation of immunological maturity.

Effects of a Quaternary Ammonium Compound on Escherichia coli1

PubMed Central

Ceglowski, W. S.; Lear, S. A.

1962-01-01

Increasing amounts of tetradecyldimethylbenzyl ammonium chloride (TAC) were lethal to an increasing proportion of an actively growing culture of Escherichia coli. The loss of nucleic acid material by actively growing E. coli did not appear to play a major role in the lethal effect. It was found that lag-phase cells were more sensitive than logarithmic-phase cells to the lethal effect of TAC. The effect of TAC on the lysozyme sensitivity of the test organism was compared with that obtained using disodium dihydrogen ethylenediaminetetraacetate (EDTA). Although TAC was found to render the test organism susceptible to lysozyme, the degree of lysis never reached that attained with EDTA. PMID:14019586

Biocatalytically active silCoat-composites entrapping viable Escherichia coli.

PubMed

Findeisen, A; Thum, O; Ansorge-Schumacher, M B

2014-02-01

Application of whole cells in industrial processes requires high catalytic activity, manageability, and viability under technical conditions, which can in principle be accomplished by appropriate immobilization. Here, we report the identification of carrier material allowing exceptionally efficient adsorptive binding of Escherichia coli whole cells hosting catalytically active carbonyl reductase from Candida parapsilosis (CPCR2). With the immobilizates, composite formation with both hydrophobic and hydrophilized silicone was achieved, yielding advanced silCoat-material and HYsilCoat-material, respectively. HYsilCoat-whole cells were viable preparations with a cell loading up to 400 mg(E. coli) · g(-1)(carrier) and considerably lower leaching than native immobilizates. SilCoat-whole cells performed particularly well in neat substrate exhibiting distinctly increased catalytic activity.

Genetic characterization of moaB mutants of Escherichia coli

PubMed Central

Kozmin, Stanislav G.; Schaaper, Roel M.

2013-01-01

The moaABCDE operon of Escherichia coli encodes enzymes essential for the biosynthesis of the molybdenum cofactor (Moco). However, the role of the moaB gene within this operon has remained enigmatic. Here, we have investigated the effect of moaB defects on two phenotypes diagnostic for Moco-deficiency: chlorate-resistance and sensitivity to the base analog 6-N-hydroxylaminopurine (HAP). We found that transposon insertions in moaB caused partial Moco-deficiency associated with chlorate-resistance, but not for HAP-sensitivity. On the other hand, in-frame deletions of moaB, or moaB overexpression, had no effect on either phenotype. Our combined data are consistent with the lack of any role for MoaB in Moco biosynthesis in E. coli. PMID:23680484

A direct detection of Escherichia coli genomic DNA using gold nanoprobes

PubMed Central

2012-01-01

Background In situation like diagnosis of clinical and forensic samples there exists a need for highly sensitive, rapid and specific DNA detection methods. Though conventional DNA amplification using PCR can provide fast results, it is not widely practised in diagnostic laboratories partially because it requires skilled personnel and expensive equipment. To overcome these limitations nanoparticles have been explored as signalling probes for ultrasensitive DNA detection that can be used in field applications. Among the nanomaterials, gold nanoparticles (AuNPs) have been extensively used mainly because of its optical property and ability to get functionalized with a variety of biomolecules. Results We report a protocol for the use of gold nanoparticles functionalized with single stranded oligonucleotide (AuNP- oligo probe) as visual detection probes for rapid and specific detection of Escherichia coli. The AuNP- oligo probe on hybridization with target DNA containing complementary sequences remains red whereas test samples without complementary DNA sequences to the probe turns purple due to acid induced aggregation of AuNP- oligo probes. The color change of the solution is observed visually by naked eye demonstrating direct and rapid detection of the pathogenic Escherichia coli from its genomic DNA without the need for PCR amplification. The limit of detection was ~54 ng for unamplified genomic DNA. The method requires less than 30 minutes to complete after genomic DNA extraction. However, by using unamplified enzymatic digested genomic DNA, the detection limit of 11.4 ng was attained. Results of UV-Vis spectroscopic measurement and AFM imaging further support the hypothesis of aggregation based visual discrimination. To elucidate its utility in medical diagnostic, the assay was validated on clinical strains of pathogenic Escherichia coli obtained from local hospitals and spiked urine samples. It was found to be 100% sensitive and proves to be highly specific without

Epidemiology and Characteristics of Escherichia coli Sequence Type 131 (ST131) from Long-Term Care Facility Residents Colonized Intestinally with Fluoroquinolone-Resistant Escherichia coli

PubMed Central

Han, Jennifer H.; Garrigan, Charles; Johnston, Brian; Nachamkin, Irving; Clabots, Connie; Bilker, Warren B.; Santana, Evelyn; Tolomeo, Pam; Maslow, Joel; Myers, Janice; Carson, Lesley; Lautenbach, Ebbing; Johnson, James R.

2016-01-01

The objective of this study was to evaluate molecular and epidemiologic factors associated with Escherichia coli sequence type 131 (ST131) among long-term care facility (LTCF) residents who acquired gastrointestinal tract colonization with fluoroquinolone-resistant E. coli (FQREC). Colonizing isolates from 37 residents who newly developed FQREC colonization at three LTCFs from 2006–2008 were evaluated. Twenty-nine (78%) of 37 total FQREC colonizing isolates were ST131. Most ST131 isolates had a distinctive combination of gyrA and parC replacement mutations. The ST131 and non-ST131 isolates differed significantly for the prevalence of many individual virulence factors but not for the proportion that qualified molecularly as extraintestinal pathogenic E. coli (ExPEC) or aggregate virulence factor scores. E. coli ST131 was highly prevalent among LTCF residents with FQREC colonization. Future studies should determine the risk factors for infection among ST131-colonized residents, and assess the potential for increased transmissibility of ST131 in the long-term care setting. PMID:27939288

Global forecast of antimicrobial resistance in invasive isolates of Escherichia coli and Klebsiella pneumoniae.

PubMed

Alvarez-Uria, Gerardo; Gandra, Sumanth; Mandal, Siddhartha; Laxminarayan, Ramanan

2018-03-01

To project future antimicrobial resistance (AMR) in Escherichia coli and Klebsiella pneumoniae. Mixed linear models were constructed from a sample of countries with AMR data in the ResistanceMap database. Inverse probability weighting methods were used to account for countries without AMR data. The estimated prevalence of AMR in 2015 was 64.5% (95% confidence interval (CI) 42-87%) for third-generation cephalosporin-resistant (3GCR) Escherichia coli, 5.8% (95% CI 1.8-9.7%) for carbapenem-resistant (CR) E. coli, 66.9% (95% CI 47.1-86.8%) for 3GCR Klebsiella pneumoniae, and 23.4% (95% CI 7.4-39.4%) for CR K. pneumoniae. The projected AMR prevalence in 2030 was 77% (95% CI 55-99.1%) for 3GCR E. coli, 11.8% (95% CI 3.7-19.9%) for CR E. coli, 58.2% (95% CI 50.2-66.1%) for 3GCR K. pneumoniae, and 52.8% (95% CI 16.3-89.3%) for CR K. pneumoniae. The models suggest that third-generation cephalosporins and carbapenems could be ineffective against a sizeable proportion of infections by E. coli and K. pneumoniae in most parts of the world by 2030, supporting both the need to enhance stewardship efforts and to prioritize research and development of new antibiotics for resistant Enterobacteriaceae. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

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

PubMed

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 < 0.001). Below mat E. coli increased as the stranded mats persisted at the beach swash zone. Water adjacent to 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 < 0.001). The attached E. coli likely acted as a reservoir for populating water underlying the mat. Fecal bacterial pathogens, however, could not be detected by microbiological culture methods either attached to mat biomass or in underlying water. Removal of 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.

EcoliWiki: a wiki-based community resource for Escherichia coli

PubMed Central

McIntosh, Brenley K.; Renfro, Daniel P.; Knapp, Gwendowlyn S.; Lairikyengbam, Chanchala R.; Liles, Nathan M.; Niu, Lili; Supak, Amanda M.; Venkatraman, Anand; Zweifel, Adrienne E.; Siegele, Deborah A.; Hu, James C.

2012-01-01

EcoliWiki is the community annotation component of the PortEco (http://porteco.org; formerly EcoliHub) project, an online data resource that integrates information on laboratory strains of Escherichia coli, its phages, plasmids and mobile genetic elements. As one of the early adopters of the wiki approach to model organism databases, EcoliWiki was designed to not only facilitate community-driven sharing of biological knowledge about E. coli as a model organism, but also to be interoperable with other data resources. EcoliWiki content currently covers genes from five laboratory E. coli strains, 21 bacteriophage genomes, F plasmid and eight transposons. EcoliWiki integrates the Mediawiki wiki platform with other open-source software tools and in-house software development to extend how wikis can be used for model organism databases. EcoliWiki can be accessed online at http://ecoliwiki.net. PMID:22064863

Non-Escherichia coli versus Escherichia coli community-acquired urinary tract infections in children hospitalized in a tertiary center: relative frequency, risk factors, antimicrobial resistance and outcome.

PubMed

Marcus, Nir; Ashkenazi, Shai; Yaari, Arnon; Samra, Zmira; Livni, Gilat

2005-07-01

Currently hospitalization for children with urinary tract infections (UTIs) is reserved for severe or complicated cases. Changes may have taken place in the characteristics and causative uropathogens of hospital-treated community-acquired UTI. To study children hospitalized in a tertiary center with community-acquired UTI, compare Escherichia coli and non-E. coli UTI, define predictors for non-E. coli UTI and elucidate the appropriate therapeutic approach. A prospective clinical and laboratory study from 2001 through 2002 in a tertiary pediatric medical center. Patients were divided by results of the urine culture into E. coli and non-E. coli UTI groups, which were compared. Of 175 episodes of culture-proved UTI, 70 (40%) were caused by non-E. coli pathogens. Non-E. coli UTI was more commonly found in children who were male (P = 0.005), who had underlying renal abnormalities (P = 0.0085) and who had received antibiotic therapy in the prior month (P = 0.0009). Non-E. coli uropathogens were often resistant to antibiotics usually recommended for initial therapy for UTI, including cephalosporins and aminoglycosides; 19% were initially treated with inappropriate empiric intravenous antibiotics (compared with 2% for E. coli UTI, P = 0.0001), with a longer hospitalization. Current treatment routines are often inappropriate for hospitalized children with non-E. coli UTI, which is relatively common in this population. The defined risk factors associated with non-E. coli UTIs and its antimicrobial resistance patterns should be considered to improve empiric antibiotic therapy for these infections.

Sucralose Increases Antimicrobial Resistance and Stimulates Recovery of Escherichia coli Mutants.

PubMed

Qu, Yilin; Li, Rongyan; Jiang, Mingshan; Wang, Xiuhong

2017-07-01

Because of heavy use of antimicrobials, antimicrobial resistance in bacteria has become of great concern. The effect of some widely used food additives such as sucralose on bacteria in the gut and the environment has also drawn increasing attention. In this study, we investigated the interaction between antimicrobials and sucralose impacting antimicrobial resistance and mutation of Escherichia coli (E. coli). To examine antimicrobial resistance and mutation frequency, different subinhibitory concentrations of sucralose were added to cultures of E.coli BW25113 that were then treated with antimicrobials, oxolinic acid, or moxifloxacin. Then the E.coli were assayed for bacterial survival and recovery of mutants resistant to an unrelated antimicrobial, rifampicin. Pre-treatment of E.coli BW25113 with 1/2 minimal inhibitory concentration (MIC) of sucralose increased the survival rate in oxolinic acid or moxifloxacin. A 1/3 MIC of sucralose increased rifampicin-resistant mutation rate of E.coli BW25113 after 72 h, while rifampicin-resistant mutation rate was increased when co-treated with 1/8 MIC, 1/4 MIC, 1/3 MIC sucralose, and oxolinic acid after 24 h. Sucralose can increase the antimicrobial resistance and mutation frequency of E.coli to some antimicrobials.

Significance of Viable but Nonculturable Escherichia coli: Induction, Detection, and Control.

PubMed

Ding, Tian; Suo, Yuanjie; Xiang, Qisen; Zhao, Xihong; Chen, Shiguo; Ye, Xingqian; Liu, Donghong

2017-03-28

Diseases caused by foodborne or waterborne pathogens are emerging. Many pathogens can enter into the viable but nonculturable (VBNC) state, which is a survival strategy when exposed to harsh environmental stresses. Pathogens in the VBNC state have the ability to evade conventional microbiological detection methods, posing a significant and potential health risk. Therefore, controlling VBNC bacteria in food processing and the environment is of great importance. As the typical one of the gram-negatives, Escherichia coli ( E. coli ) is a widespread foodborne and waterborne pathogenic bacterium and is able to enter into a VBNC state in extreme conditions (similar to the other gram-negative bacteria), including inducing factors and resuscitation stimulus. VBNC E. coli has the ability to recover both culturability and pathogenicity, which may bring potential health risk. This review describes the concrete factors (nonthermal treatment, chemical agents, and environmental factors) that induce E. coli into the VBNC state, the condition or stimulus required for resuscitation of VBNC E. coli , and the methods for detecting VBNC E. coli . Furthermore, the mechanism of genes and proteins involved in the VBNC E. coli is also discussed in this review.

Locally Acquired mcr-1 in Escherichia coli, Australia, 2011 and 2013.

PubMed

Ellem, Justin A; Ginn, Andrew N; Chen, Sharon C-A; Ferguson, John; Partridge, Sally R; Iredell, Jonathan R

2017-07-01

We identified discrete importation events of the mcr-1 gene on incompatibility group IncI2 plasmids in Escherichia coli isolated from patients in New South Wales, Australia, in 2011 and 2013. mcr-1 is present in a small minority of colistin-resistant Enterobacteriaceae and appears not to be established locally.

Accumulation of peptidyl tRNA is lethal to Escherichia coli.

PubMed Central

Menninger, J R

1979-01-01

A mutant strain of Escherichia coli with temperature-sensitive peptidyl-tRNA hydrolase grows at 30 degrees C but, when shifted to 40 degrees C, dies at rates affected by physiological, pharmacological, and genetical perturbations. The rate of killing correlates with the relative accumulation of peptidyl-tRNA, suggesting that it is responsible for the death of the cells. PMID:368041

Escherichia coli O157:H7 virulence factors differentially impact cattle and bison macrophage killing

USDA-ARS?s Scientific Manuscript database

Enterohemorrhagic Escherichia coli O157:H7 frequently colonizes the gastrointestinal tract of ruminants, including cattle and bison, which are a reservoir of the zoonotic bacteria to humans. Healthy animals do not experience the clinical symptoms of disease that is induced by E. coli O157:H7 in huma...

Clonal relatedness of Escherichia coli from patients with extraintestinal infections and healthy chickens in Egypt

USDA-ARS?s Scientific Manuscript database

ß-lactam resistant Escherichia coli in both humans and food animals is a cause for concern on a worldwide level. Clinical samples from patients with extraintestinal infections and healthy broiler chickens were collected from Egypt during the 2nd half of 2015 and examined for the presence of E. coli....

Draft Genomic Sequencing of Six Potential Extraintestinal Pathogenic Escherichia coli Isolates from Retail Chicken Meat

PubMed Central

Xu, Aixia; Johnson, James R.; Sheen, Shiowshuh; Needleman, David S.

2018-01-01

ABSTRACT Potential extraintestinal pathogenic Escherichia coli strains DP254, WH333, WH398, F356, FEX675, and FEX725 were isolated from retail chicken meat products. Here, we report the draft genome sequences for these six E. coli isolates, which are currently being used in food safety research. PMID:29798928

Engineering Escherichia coli coculture systems for the production of biochemical products.

PubMed

Zhang, Haoran; Pereira, Brian; Li, Zhengjun; Stephanopoulos, Gregory

2015-07-07

Engineering microbial consortia to express complex biosynthetic pathways efficiently for the production of valuable compounds is a promising approach for metabolic engineering and synthetic biology. Here, we report the design, optimization, and scale-up of an Escherichia coli-E. coli coculture that successfully overcomes fundamental microbial production limitations, such as high-level intermediate secretion and low-efficiency sugar mixture utilization. For the production of the important chemical cis,cis-muconic acid, we show that the coculture approach achieves a production yield of 0.35 g/g from a glucose/xylose mixture, which is significantly higher than reported in previous reports. By efficiently producing another compound, 4-hydroxybenzoic acid, we also demonstrate that the approach is generally applicable for biosynthesis of other important industrial products.

Understanding the association of Escherichia coli with diverse macroalgae in the lagoon of Venice

NASA Astrophysics Data System (ADS)

Quero, Grazia M.; Fasolato, Luca; Vignaroli, Carla; Luna, Gian Marco

2015-06-01

Recent studies provided evidence that the macroalga Cladopohora in lakes hosts associated Escherichia coli, with consequences on the environmental and human health. We expanded these investigations to other macroalgae (Ulva spp., Sargassum muticum and Undaria pinnatifida) widespread in the lagoon of Venice (Italy). Attached E. coli were abundant, accounting up to 3,250 CFU gram-1 of alga. Macroalgal-associated isolates belonged to all E. coli phylogroups, including pathogenic ones, and to Escherichia cryptic clades. Attached E. coli showed potential to grow even at in situ temperature on macroalgal extracts as only source of carbon and nutrients, and ability to produce biofilm in vitro. The genotypic diversity of the attached isolates was high, with significant differences between algae and the overlying water. Our evidences suggest that attached populations consist of both resident and transient strains, likely resulting from the heterogeneous input of fecal bacteria from the city. We report that cosmopolitan and invasive macroalgae may serve as source of E. coli, including pathogenic genotypes, and that this habitat can potentially support their growth. Considering the global diffusion of the macroalgae here studied, this phenomenon is likely occurring in other coastal cities worldwide and deserves further investigations from either the sanitary and ecological perspectives.

Understanding the association of Escherichia coli with diverse macroalgae in the lagoon of Venice

PubMed Central

Quero, Grazia M.; Fasolato, Luca; Vignaroli, Carla; Luna, Gian Marco

2015-01-01

Recent studies provided evidence that the macroalga Cladopohora in lakes hosts associated Escherichia coli, with consequences on the environmental and human health. We expanded these investigations to other macroalgae (Ulva spp., Sargassum muticum and Undaria pinnatifida) widespread in the lagoon of Venice (Italy). Attached E. coli were abundant, accounting up to 3,250 CFU gram−1 of alga. Macroalgal-associated isolates belonged to all E. coli phylogroups, including pathogenic ones, and to Escherichia cryptic clades. Attached E. coli showed potential to grow even at in situ temperature on macroalgal extracts as only source of carbon and nutrients, and ability to produce biofilm in vitro. The genotypic diversity of the attached isolates was high, with significant differences between algae and the overlying water. Our evidences suggest that attached populations consist of both resident and transient strains, likely resulting from the heterogeneous input of fecal bacteria from the city. We report that cosmopolitan and invasive macroalgae may serve as source of E. coli, including pathogenic genotypes, and that this habitat can potentially support their growth. Considering the global diffusion of the macroalgae here studied, this phenomenon is likely occurring in other coastal cities worldwide and deserves further investigations from either the sanitary and ecological perspectives. PMID:26043415

Understanding the association of Escherichia coli with diverse macroalgae in the lagoon of Venice.

PubMed

Quero, Grazia M; Fasolato, Luca; Vignaroli, Carla; Luna, Gian Marco

2015-06-04

Recent studies provided evidence that the macroalga Cladopohora in lakes hosts associated Escherichia coli, with consequences on the environmental and human health. We expanded these investigations to other macroalgae (Ulva spp., Sargassum muticum and Undaria pinnatifida) widespread in the lagoon of Venice (Italy). Attached E. coli were abundant, accounting up to 3,250 CFU gram(-1) of alga. Macroalgal-associated isolates belonged to all E. coli phylogroups, including pathogenic ones, and to Escherichia cryptic clades. Attached E. coli showed potential to grow even at in situ temperature on macroalgal extracts as only source of carbon and nutrients, and ability to produce biofilm in vitro. The genotypic diversity of the attached isolates was high, with significant differences between algae and the overlying water. Our evidences suggest that attached populations consist of both resident and transient strains, likely resulting from the heterogeneous input of fecal bacteria from the city. We report that cosmopolitan and invasive macroalgae may serve as source of E. coli, including pathogenic genotypes, and that this habitat can potentially support their growth. Considering the global diffusion of the macroalgae here studied, this phenomenon is likely occurring in other coastal cities worldwide and deserves further investigations from either the sanitary and ecological perspectives.

Cranberry xyloglucan structure and inhibition of Escherichia coli adhesion to epithelial cells

USDA-ARS?s Scientific Manuscript database

Cranberry juice has been used to treat urinary tract infections based on scientific reports of proanthocyanidin anti-adhesion activity for Escherichia coli as well as folklore. Xyloglucan oligosaccharides were also detected in cranberry juice and the pulp remaining following commercial juice extract...

An overview of molecular stress response mechanisms in Escherichia coli contributing to survival of Shiga toxin-producing Escherichia coli during raw milk cheese production.

PubMed

Peng, Silvio; Tasara, Taurai; Hummerjohann, Jörg; Stephan, Roger

2011-05-01

The ability of foodborne pathogens to survive in certain foods mainly depends on stress response mechanisms. Insight into molecular properties enabling pathogenic bacteria to survive in food is valuable for improvement of the control of pathogens during food processing. Raw milk cheeses are a potential source for human infections with Shiga toxin-producing Escherichia coli (STEC). In this review, we focused on the stress response mechanisms important for allowing STEC to survive raw milk cheese production processes. The major components and regulation pathways for general, acid, osmotic, and heat shock stress responses in E. coli and the implications of these responses for the survival of STEC in raw milk cheeses are discussed.

Escherichia coli O157:H7 in Ecuador: animal reservoirs, yet no human disease.

PubMed

Trueba, Gabriel; Garcés, Verónica; V, Verónica Barragan; Colman, Rebecca E; Seymour, Meagan; Vogler, Amy J; Keim, Paul

2013-05-01

Escherichia coli O157:H7 is frequently isolated from cases of diarrhea in many industrialized countries; however, it is seldom found in developing countries. The present manuscript reports the presence of E. coli O157:H7 in Ecuadorian livestock, a country where enterohemorrhagic E. coli disease in humans has never been reported. The Ecuadorian isolates were genetically related to some strains linked to clinical cases in the United States as assessed by multiple-locus variable number tandem repeat (VNTR) analysis.

Studies of the Escherichia coli Rsd-sigma70 complex.

PubMed

Westblade, Lars F; Ilag, Leopold L; Powell, Andrew K; Kolb, Annie; Robinson, Carol V; Busby, Stephen J W

2004-01-16

Escherichia coli Rsd protein was previously identified on the basis of its binding to the RNA polymerase sigma(70) subunit. The Rsd-sigma(70) complex has been studied using different methods. Our data show that Rsd associates with sigma(70) to form a complex with a stoichiometry of 1:1. Alanine scanning and deletion mutagenesis were used to locate regions of sigma(70) that are required for the formation of the Rsd-sigma(70) complex.

Antibiotics for asymptomatic bacteriuria in pregnancy.

PubMed

Smaill, F

2001-01-01

Up to 30% of mothers develop acute pyelonephritis if asymptomatic bacteriuria is untreated. Asymptomatic bacteriuria may have a role in preterm birth or it may be a marker for low socioeconomic status which is associated with low birth weight. The objective of this review was to assess the effect of antibiotic treatment for asymptomatic bacteriuria on persistent bacteriuria during pregnancy, the risk of preterm delivery, and the development of pyelonephritis. I searched the Cochrane Pregnancy and Childbirth Group trials register. Date of last search: December 2000. Randomised trials comparing antibiotic treatment with placebo or no treatment in pregnant women with asymptomatic bacteriuria found on antenatal screening. Trial quality was assessed. Fourteen studies were included. Overall the study quality was not strong. Antibiotic treatment compared to placebo or no treatment was effective in clearing asymptomatic bacteriuria (odds ratio 0.07, 95% confidence interval 0.05 to 0.10). The incidence of pyelonephritis was reduced (odds ratio 0.24, 95% confidence interval 0.19 to 0.32). Antibiotic treatment was also associated with a reduction in the incidence of preterm delivery or low birth weight babies (odds ratio 0.60, 95% confidence interval 0.45 to 0.80). Antibiotic treatment is effective in reducing the risk of pyelonephritis in pregnancy. An apparent reduction in preterm delivery is consistent with current theories about the role of infection in preterm birth, but this association should be interpreted with caution.

Antibiotics for asymptomatic bacteriuria in pregnancy.

PubMed

Smaill, F; Vazquez, J C

2007-04-18

Asymptomatic bacteriuria occurs in 2% to 10% of pregnancies and, if not treated, up to 30% of mothers will develop acute pyelonephritis. Asymptomatic bacteriuria has been associated with low birthweight and preterm delivery. To assess the effect of antibiotic treatment for asymptomatic bacteriuria on persistent bacteriuria during pregnancy, the development of pyelonephritis and the risk of low birthweight and preterm delivery. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2007). Randomized trials comparing antibiotic treatment with placebo or no treatment in pregnant women with asymptomatic bacteriuria found on antenatal screening. We assessed trial quality. Fourteen studies were included. Overall the study quality was poor. Antibiotic treatment compared to placebo or no treatment was effective in clearing asymptomatic bacteriuria (risk ratio (RR) 0.25, 95% confidence interval (CI) 0.14 to 0.48). The incidence of pyelonephritis was reduced (RR 0.23, 95% CI 0.13 to 0.41). Antibiotic treatment was also associated with a reduction in the incidence of low birthweight babies (RR 0.66, 95% CI 0.49 to 0.89) but a difference in preterm delivery was not seen. Antibiotic treatment is effective in reducing the risk of pyelonephritis in pregnancy. A reduction in low birthweight is consistent with current theories about the role of infection in adverse pregnancy outcomes, but this association should be interpreted with caution given the poor quality of the included studies.

Colonization with Extraintestinal Pathogenic Escherichia coli among Nursing Home Residents and Its Relationship to Fluoroquinolone Resistance

PubMed Central

Maslow, Joel N.; Lautenbach, Ebbing; Glaze, Thomas; Bilker, Warren; Johnson, James R.

2004-01-01

In a cross-sectional fecal prevalence survey involving 49 residents of a Veterans Affairs nursing home, 59% of subjects were colonized with extraintestinal pathogenic Escherichia coli (ExPEC), 22% were colonized with adhesin-positive E. coli, and 51% were colonized with fluoroquinolone-resistant E. coli. Among 80 unique isolates, adhesins correlated negatively and aerobactin correlated positively with fluoroquinolone resistance. PMID:15328142

Deactivation of Escherichia coli by the plasma needle

NASA Astrophysics Data System (ADS)

Sladek, R. E. J.; Stoffels, E.

2005-06-01

In this paper we present a parameter study on deactivation of Escherichia coli (E. coli) by means of a non-thermal plasma (plasma needle). The plasma needle is a small-sized (1 mm) atmospheric glow sustained by radio-frequency excitation. This plasma will be used to disinfect heat-sensitive objects; one of the intended applications is in vivo deactivation of dental bacteria: destruction of plaque and treatment of caries. We use E. coli films plated on agar dishes as a model system to optimize the conditions for bacterial destruction. Plasma power, treatment time and needle-to-sample distance are varied. Plasma treatment of E. coli films results in formation of a bacteria-free void with a size up to 12 mm. 104-105 colony forming units are already destroyed after 10 s of treatment. Prolongation of treatment time and usage of high powers do not significantly improve the destruction efficiency: short exposure at low plasma power is sufficient. Furthermore, we study the effects of temperature increase on the survival of E. coli and compare it with thermal effects of the plasma. The population of E. coli heated in a warm water bath starts to decrease at temperatures above 40°C. Sample temperature during plasma treatment has been monitored. The temperature can reach up to 60°C at high plasma powers and short needle-to-sample distances. However, thermal effects cannot account for bacterial destruction at low power conditions. For safe and efficient in vivo disinfection, the sample temperature should be kept low. Thus, plasma power and treatment time should not exceed 150 mW and 60 s, respectively.

Asymptomatic bacteriuria

MedlinePlus

Dull RB, Friedman SK, Risoldi ZM, Rice EC, Starlin RC, Destache CJ. Antimicrobial treatment of asymptomatic bacteriuria in noncatheterized adults: a systematic review. Pharmacotherapy . 2014;34(9):941-960. PMID: 24807583 ...

Predominance of the ac variant in K88-positive Escherichia coli isolates from swine.

PubMed Central

Westerman, R B; Mills, K W; Phillips, R M; Fortner, G W; Greenwood, J M

1988-01-01

Monoclonal antibodies to K88ac and K88ab were used in enzyme-linked immunosorbent assays on Escherichia coli cultures known to produce K88 pili. A total of 415 K88-positive E. coli isolates from nine states were all found to be the K88ac variant. The cultures tested were isolated during the years 1976 to 1985. PMID:3277990

The Essential Genome of Escherichia coli K-12.

PubMed

Goodall, Emily C A; Robinson, Ashley; Johnston, Iain G; Jabbari, Sara; Turner, Keith A; Cunningham, Adam F; Lund, Peter A; Cole, Jeffrey A; Henderson, Ian R

2018-02-20

Transposon-directed insertion site sequencing (TraDIS) is a high-throughput method coupling transposon mutagenesis with short-fragment DNA sequencing. It is commonly used to identify essential genes. Single gene deletion libraries are considered the gold standard for identifying essential genes. Currently, the TraDIS method has not been benchmarked against such libraries, and therefore, it remains unclear whether the two methodologies are comparable. To address this, a high-density transposon library was constructed in Escherichia coli K-12. Essential genes predicted from sequencing of this library were compared to existing essential gene databases. To decrease false-positive identification of essential genes, statistical data analysis included corrections for both gene length and genome length. Through this analysis, new essential genes and genes previously incorrectly designated essential were identified. We show that manual analysis of TraDIS data reveals novel features that would not have been detected by statistical analysis alone. Examples include short essential regions within genes, orientation-dependent effects, and fine-resolution identification of genome and protein features. Recognition of these insertion profiles in transposon mutagenesis data sets will assist genome annotation of less well characterized genomes and provides new insights into bacterial physiology and biochemistry. IMPORTANCE Incentives to define lists of genes that are essential for bacterial survival include the identification of potential targets for antibacterial drug development, genes required for rapid growth for exploitation in biotechnology, and discovery of new biochemical pathways. To identify essential genes in Escherichia coli , we constructed a transposon mutant library of unprecedented density. Initial automated analysis of the resulting data revealed many discrepancies compared to the literature. We now report more extensive statistical analysis supported by both

Distribution of Diverse Escherichia coli between Cattle and Pasture.

PubMed

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

2017-09-27

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 isolates maintaining a population in pasture soil over winter. Soil, bovine fecal, and run-off samples were collected before and after the introduction of cattle to the pasture. Isolates (363) were genotyped by uidA and mutS sequences and phylogrouping, and evaluated for curli formation (Rough, Dry, And Red, or RDAR). Three types of clusters emerged, viz. bovine-associated, clusters devoid of cattle isolates and representing isolates endemic to the pasture environment, and clusters with both. All isolates clustered with strains of E. coli sensu stricto, distinct from the cryptic species Clades I, III, IV, and V. Pasture soil endemic and bovine fecal populations had very different phylogroup distributions, indicating niche partitioning. The soil endemic population was largely comprised of phylogroup B1 and had a higher average RDAR score than other isolates. These results indicate the existence of environmental E. coli strains that are phylogenetically distinct from bovine fecal isolates, and that have the ability to maintain populations in the soil environment.

Distribution of Diverse Escherichia coli between Cattle and Pasture

PubMed Central

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 isolates maintaining a population in pasture soil over winter. Soil, bovine fecal, and run-off samples were collected before and after the introduction of cattle to the pasture. Isolates (363) were genotyped by uidA and mutS sequences and phylogrouping, and evaluated for curli formation (Rough, Dry, And Red, or RDAR). Three types of clusters emerged, viz. bovine-associated, clusters devoid of cattle isolates and representing isolates endemic to the pasture environment, and clusters with both. All isolates clustered with strains of E. coli sensu stricto, distinct from the cryptic species Clades I, III, IV, and V. Pasture soil endemic and bovine fecal populations had very different phylogroup distributions, indicating niche partitioning. The soil endemic population was largely comprised of phylogroup B1 and had a higher average RDAR score than other isolates. These results indicate the existence of environmental E. coli strains that are phylogenetically distinct from bovine fecal isolates, and that have the ability to maintain populations in the soil environment. PMID:28747587

Asymptomatic bacteriuria: when to screen and when to treat.

PubMed

Nicolle, Lindsay E

2003-06-01

Asymptomatic bacteriuria is common. Populations with structural or functional abnormalities of the genitourinary tract may have an exceedingly high prevalence of bacteriuria, but even healthy individuals frequently have positive urine cultures. Asymptomatic bacteriuria is seldom associated with adverse outcomes. Pregnant women and individuals who are to undergo traumatic genitourinary interventions are at risk for complications of bacteriuria and benefit from screening and treatment programs. Although screening is recommended for renal transplant recipients, the benefits for these patients are less clear. For other populations, including most bacteriuric individuals, negative outcomes attributable to asymptomatic bacteriuria have not been described. Treatment of asymptomatic bacteriuria in these patients is not beneficial and, in fact, may be associated with harmful outcomes, such as increased short-term frequency of symptomatic infection, adverse drug effects, and reinfection with organisms of increased antimicrobial resistance. Screening for asymptomatic bacteriuria and treatment is recommended for only selected groups where benefit has been shown. Many research questions still need to be addressed. Different populations have unique risk factors, and the benefits and risks of different management approaches for asymptomatic bacteriuria must continue to be addressed systematically in appropriate clinical trials.

Media composition and incubation temperature affect Congo red dye affinity of Shiga toxin-producing Escherichia coli

USDA-ARS?s Scientific Manuscript database

Background: Escherichia coli biofilm formation is dependent on curli fimbriae and cellulose, and the expression of both varies among Shiga toxin-producing E. coli (STEC). Curli and cellulose expression are often identified by their affinity for Congo red dye (CR) but media composition and incubation...

Engineered probiotic Escherichia coli can eliminate and prevent Pseudomonas aeruginosa gut infection in animal models

PubMed Central

Hwang, In Young; Koh, Elvin; Wong, Adison; March, John C.; Bentley, William E.; Lee, Yung Seng; Chang, Matthew Wook

2017-01-01

Bacteria can be genetically engineered to kill specific pathogens or inhibit their virulence. We previously developed a synthetic genetic system that allows a laboratory strain of Escherichia coli to sense and kill Pseudomonas aeruginosa in vitro. Here, we generate a modified version of the system, including a gene encoding an anti-biofilm enzyme, and use the probiotic strain Escherichia coli Nissle 1917 as host. The engineered probiotic shows in vivo prophylactic and therapeutic activity against P. aeruginosa during gut infection in two animal models (Caenorhabditis elegans and mice). These findings support the further development of engineered microorganisms with potential prophylactic and therapeutic activities against gut infections. PMID:28398304

Sedimentation and gravitational instability of Escherichia coli Suspension

NASA Astrophysics Data System (ADS)

Salin, Dominique; Douarche, Carine

2017-11-01

The successive runs and tumbles of Escherichia coli bacteria provide an active matter suspension of rod-like particles with a large swimming, Brownian like, diffusion. As opposed to inactive elongated particles, this diffusion prevents clustering of the particles and hence instability in the gravity field. We measure the time dependent E . coli concentration profile during their sedimentation. After some hours, due to the dioxygen consumption, a motile / non-motile front forms leading to a Rayleigh-Taylor type gravitational instability. Analysing both sedimentation and instability in the framework of active particle suspensions, we can measure the relevant bacteria hydrodynamic characteristics such as its single particle sedimentation velocity and its hindrance volume. Comparing these quantities to the ones of equivalent passive particles (ellipsoid, rod) we tentatively infer the effective shape and size of the bacteria involved in its buoyancy induced advection and diffusion. Laboratoire FAST University Paris Saclay France.

Shiga toxin-producing escherichia coli: detection, differentiation, and implications for food safety

USDA-ARS?s Scientific Manuscript database

All unprocessed food products typically harbor microorganisms. Some foods and the components that go into food production may contain pathogenic microorganisms such as Shiga toxin-producing Escherichia coli (STECs). When consumed, these STECs can cause serious illness or even death. In 2011, an out...

Microbiota response to Escherichia coli O157:H7 colonization in cattle

USDA-ARS?s Scientific Manuscript database

Cattle are primary reservoir of Shiga toxin-producing Escherichia coli (STEC). Field studies indicate STEC colonization influences gut microbiota composition in beef and dairy cattle. In this pilot study, we evaluated the bovine gut microbiota after STEC O157 (O157) challenge under experimental con...

Enhancement of L-cysteine production by disruption of yciW in Escherichia coli.

PubMed

Kawano, Yusuke; Ohtsu, Iwao; Takumi, Kazuhiro; Tamakoshi, Ai; Nonaka, Gen; Funahashi, Eri; Ihara, Masaki; Takagi, Hiroshi

2015-02-01

Using in silico analysis, the yciW gene of Escherichia coli was identified as a novel L-cysteine regulon that may be regulated by the transcriptional activator CysB for sulfur metabolic genes. We found that overexpression of yciW conferred tolerance to L-cysteine, but disruption of yciW increased L-cysteine production in E. coli. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Differential gene expression of three mastitis-causing Escherichia coli strains grown under planktonic, swimming, and swarming culture conditions

USDA-ARS?s Scientific Manuscript database

Escherichia coli is a leading cause of intramammary infections in dairy cattle and is typically transient in nature. However, in a minority of cases, E. coli can cause persistent infections. Although the mechanisms that allow for a persistent intramammary E. coli infection are not fully understood...

Urinary tract infections in pregnancy.

PubMed

Ovalle, A; Levancini, M

2001-01-01

Urinary tract infections are very common during pregnancy. Escherichia coli is the most common pathogen isolated from pregnant women. Ampicillin should not be used because of its high resistance to Escherichia coli. Pyelonephritis can cause morbidity and can be life-threatening to both mother and fetus. Second and third-generation cephalosporins are recommended for treatment, administered initially intravenously during hospitalization. Cultures and the study of virulence factors of uropathogenic Escherichia coli are recommended for the adequate management of pyelonephritis. The lower genital tract infection associated with pyelonephritis is responsible for the failure of antibiotic treatment. Asymptomatic bacteriuria can evolve into cystitis or pyelonephritis. All pregnant women should be routinely screened for bacteriuria using urine culture, and should be treated with nitrofurantoin, sulfixosazole or first-generation cephalosporins. Recurrent urinary infection should be treated with prophylactic antibiotics. Pregnant women who develop urinary tract infections with group B streptococcal infection should be treated with prophylactic antibiotics during labour to prevent neonatal sepsis. Preterm delivery is frequent. Evidence suggests that infection plays a role in the pathogenesis of preterm labour. Experimental models in pregnant mice support the theory that Escherichia coli propagated by the transplacental route, involving bacterial adhesins, induces preterm delivery, but this has not been demonstrated in humans. Ascending lower genital tract infections are the most probable cause of preterm delivery, but this remains to be proved.

Low intensity infrared laser induces filamentation in Escherichia coli cells

NASA Astrophysics Data System (ADS)

Fonseca, A. S.; Presta, G. A.; Geller, M.; Paoli, F.

2011-10-01

Low intensity continuous wave and pulsed emission modes laser is used in treating many diseases and the resulting biostimulative effect on tissues has been described, yet the photobiological basis is not well understood. The aim of this wok was to evaluate, using bacterial filamentation assay, effects of laser on Escherichia coli cultures in exponential and stationary growth phase. E. coli cultures, proficient and deficient on DNA repair, in exponential and stationary growth phase, were exposed to low intensity infrared laser, aliquots were spread onto microscopic slides, stained by Gram method, visualized by optical microscopy, photographed and percentage of bacterial filamentation were determined. Low intensity infrared laser with therapeutic fluencies and different emission modes can induce bacterial filamentation in cultures of E. coli wild type, fpg/ mutM, endonuclease III and exonuclease III mutants in exponential and stationary growth phase. This study showed induction of bacterial, filamentation in E. coli cultures expose to low intensity infrared laser and attention to laser therapy protocols, which should take into account fluencies, wavelengths, tissue conditions, and genetic characteristics of cells before beginning treatment.

Overexpression of an archaeal geranylgeranyl diphosphate synthase in Escherichia coli cells.

PubMed

Ohto, C; Nakane, H; Hemmi, H; Ohnuma, S; Obata, S; Nishino, T

1998-06-01

An archaeal geranylgeranyl diphosphate synthase was overexpressed in Escherichia coli cells as fusion proteins. These fusion proteins retained their thermostability and had higher specific activity than did a partially purified native enzyme Previously reported. We purified 24.3 mg of MBP (maltose-binding protein)-fusion protein and 5.4 mg of GST (glutathione S-transferase)-fusion protein from a one-liter culture of E. coli. The MBP-fusion proteins existed in dimer, tetramer, octamer, or dodecamer form, and their product specificities were altered according to the oligomerization. The MBP-fusion protein has protease-sensitive sites in the portion corresponding to geranylgeranyl diphosphate synthase.

Tellurite-exposed Escherichia coli exhibits increased intracellular {alpha}-ketoglutarate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinoso, Claudia A.; Auger, Christopher; Appanna, Vasu D.

2012-05-18

Highlights: Black-Right-Pointing-Pointer Tellurite-exposed E. coli exhibits decreased {alpha}-KG dehydrogenase activity. Black-Right-Pointing-Pointer Cells lacking {alpha}-KGDH genes are more sensitive to ROS than isogenic, wt E. coli. Black-Right-Pointing-Pointer KG accumulation may serve to face tellurite-mediated oxidative damage in E. coli. -- Abstract: The tellurium oxyanion tellurite is toxic to most organisms because of its ability to generate oxidative stress. However, the detailed mechanism(s) how this toxicant interferes with cellular processes have yet to be fully understood. As part of our effort to decipher the molecular interactions of tellurite with living systems, we have evaluated the global metabolism of {alpha}-ketoglutarate a known antioxidantmore » in Escherichia coli. Tellurite-exposed cells displayed reduced activity of the KG dehydrogenase complex (KGDHc), resulting in increased intracellular KG content. This complex's reduced activity seems to be due to decreased transcription in the stressed cells of sucA, a gene that encodes the E1 component of KGDHc. Furthermore, it was demonstrated that the increase in total reactive oxygen species and superoxide observed upon tellurite exposure was more evident in wild type cells than in E. coli with impaired KGDHc activity. These results indicate that KG may be playing a pivotal role in combating tellurite-mediated oxidative damage.« less

Concerted control of Escherichia coli cell division

PubMed Central

Osella, Matteo; Nugent, Eileen; Cosentino Lagomarsino, Marco

2014-01-01

The coordination of cell growth and division is a long-standing problem in biology. Focusing on Escherichia coli in steady growth, we quantify cell division control using a stochastic model, by inferring the division rate as a function of the observable parameters from large empirical datasets of dividing cells. We find that (i) cells have mechanisms to control their size, (ii) size control is effected by changes in the doubling time, rather than in the single-cell elongation rate, (iii) the division rate increases steeply with cell size for small cells, and saturates for larger cells. Importantly, (iv) the current size is not the only variable controlling cell division, but the time spent in the cell cycle appears to play a role, and (v) common tests of cell size control may fail when such concerted control is in place. Our analysis illustrates the mechanisms of cell division control in E. coli. The phenomenological framework presented is sufficiently general to be widely applicable and opens the way for rigorous tests of molecular cell-cycle models. PMID:24550446

Enteropathogenic Escherichia coli: foe or innocent bystander?

PubMed Central

Hu, Jia; Torres, Alfredo G.

2015-01-01

Enteropathogenic Escherichia coli (EPEC) remain one the most important pathogens infecting children and they are one of the main causes of persistent diarrhea worldwide. Historically, typical EPEC (tEPEC), defined as those isolates with the attaching and effacement (A/E) genotype (eae+), which possess bfpA+ and lack the stx- genes are found strongly associated with diarrheal cases. However, occurrence of atypical EPEC (aEPEC; eae+ bfpA- stx-) in diarrheal and asymptomatic hosts has made investigators question the role of these pathogens in human disease. Current epidemiological data is helping answering the question whether EPEC is mainly a foe or an innocent bystander during infection. PMID:25726041

Impact of diversity of colonizing strains on strategies for sampling Escherichia coli from fecal specimens.

PubMed

Lautenbach, Ebbing; Bilker, Warren B; Tolomeo, Pam; Maslow, Joel N

2008-09-01

Of 49 subjects, 21 were colonized with more than one strain of Escherichia coli and 12 subjects had at least one strain present in fewer than 20% of colonies. The ability to accurately characterize E. coli strain diversity is directly related to the number of colonies sampled and the underlying prevalence of the strain.

Evaluation of a rapid tube assay for presumptive identification of Escherichia coli from veterinary specimens.

PubMed Central

Iritani, B; Inzana, T J

1988-01-01

Three hundred sixty-six isolates of gram-negative, oxidase-negative bacteria from veterinary specimens were tested by a tube test for identification as Escherichia coli by production within 60 min of indole, beta-galactosidase, and beta-glucuronidase. The test correctly identified 255 of 269 isolates of E. coli (95% sensitivity) and correctly indicated that 97 of 97 isolates were not E. coli (100% specificity). We conclude that production of indole, beta-galactosidase, and beta-glucuronidase as measured by a rapid tube test is useful for identification of E. coli from veterinary specimens. PMID:3128581

Inactivation of Escherichia coli on tomatoes using a ultraviolet(LED)light

USDA-ARS?s Scientific Manuscript database

The recently developed UV LED has been shown effective at inactivating bacteria in water, but its ability to inactivate bacteria on foods is unknown. Escherichia coli in solution and dried on the surface of tomatoes was exposed to 255 nm UV from a LED, with a forward voltage of 6.5 V operating at 20...

Antimicrobial Treatment of Asymptomatic Bacteriuria in Healthy Ambulatory Subjects.

ERIC Educational Resources Information Center

Zhanel, George G.

1990-01-01

The treatment of urinary tract infections is discussed. Specific issues considered include the definition of asymptomatic bacteriuria, the prevalence of asymptomatic bacteriuria, the controversies of who should be treated, and antimicrobial treatment of asymptomatic bacteriuria. (MLW)

Purification and characterization of Escherichia coli MreB protein.

PubMed

Nurse, Pearl; Marians, Kenneth J

2013-02-01

The actin homolog MreB is required in rod-shaped bacteria for maintenance of cell shape and is intimately connected to the holoenzyme that synthesizes the peptidoglycan layer. The protein has been reported variously to exist in helical loops under the cell surface, to rotate, and to move in patches in both directions around the cell surface. Studies of the Escherichia coli protein in vitro have been hampered by its tendency to aggregate. Here we report the purification and characterization of native E. coli MreB. The protein requires ATP hydrolysis for polymerization, forms bundles with a left-hand twist that can be as long as 4 μm, forms sheets in the presence of calcium, and has a critical concentration for polymerization of 1.5 μM.

Purification and Characterization of Escherichia coli MreB Protein*

PubMed Central

Nurse, Pearl; Marians, Kenneth J.

2013-01-01

The actin homolog MreB is required in rod-shaped bacteria for maintenance of cell shape and is intimately connected to the holoenzyme that synthesizes the peptidoglycan layer. The protein has been reported variously to exist in helical loops under the cell surface, to rotate, and to move in patches in both directions around the cell surface. Studies of the Escherichia coli protein in vitro have been hampered by its tendency to aggregate. Here we report the purification and characterization of native E. coli MreB. The protein requires ATP hydrolysis for polymerization, forms bundles with a left-hand twist that can be as long as 4 μm, forms sheets in the presence of calcium, and has a critical concentration for polymerization of 1.5 μm. PMID:23235161

Continuous-sterilization system that uses photosemiconductor powders. [Escherichia coli

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsunaga, T.; Tomoda, R.; Nakajima, T.

1988-06-01

We report a novel photochemical sterilization system in which Escherichia coli cells were sterilized with photosemiconductor powders (titanium oxide). For sterilization that could be used in practice, it was necessary to separate the TiO/sub 2/ powders from the cell suspension. Therefore, semiconductor powders were immobilized on acetylcellulose membranes. We constructed a continuous-sterilization system consisting of TiO/sub 2/-immobilized acetylcellulose membrane reactor, a mercury lamp, and a masterflex pump. As a result, under the various sterilization conditions examined, E.coli (10/sup 2/ cells per ml) was sterilized to < 1% survival when the cell suspension flowed in this system at a mean residencemore » time of 16.0 min under irradiation (1800 microeinsteins/m/sup 2/ per s). We found that this system was reusable.« less

Novel model to study virulence determinants of Escherichia coli K1.

PubMed

Khan, Naveed Ahmed; Goldsworthy, Graham John

2007-12-01

It is shown here for the first time that locusts can be used as a model to study Escherichia coli K1 pathogenesis. E. coli K-12 strain HB101 has very low pathogenicity to locusts and does not invade the locust brain, whereas the injection of 2 x 10(6) E. coli K1 strain RS218 (O18:K1:H7) kills almost 100% of locusts within 72 h and invades the brain within 24 h of injection. Both mortality and invasion of the brain in locusts after injection of E. coli K1 require at least two of the known virulence determinants shown for mammals. Thus, deletion mutants that lack outer membrane protein A or cytotoxic necrotizing factor 1 have reduced abilities to kill locusts and to invade the locust brain compared to the parent E. coli K1. Interestingly, deletion mutants lacking FimH or the NeuDB gene cluster are still able to cause high mortality. It is argued that the likely existence of additional virulence determinants can be investigated in vivo by using this insect system.

Multiplex quantification of Escherichia coli, Salmonella typhi and Vibrio cholera with three DNA targets in single reaction assay.

PubMed

Jangampalli Adi, Pradeepkiran; Naidu, Jagadish R; Matcha, Bhaskar

2017-09-01

Escherichia coli (E. coli), Salmonella typhi and Vibrio cholera harmful pathogens, which causes various diseases in humans. Rapid diagnosis of bacterial infection is an important for patient management and appropriate therapy during the early phase of the bacterial infected diseases. Among the existing techniques for identifying pathogens were less sensitive and time-consuming processes. In the present study total, 48 clinical 31 blood and 17 urine samples of patients suspected with the infections were collected from SVRR Hospital and used to detect the pathogens. Multiplex polymerase chain reaction (PCR) assay was set to design for the identification of Escherichia coli, Salmonella typhi and Vibrio cholera from the different clinical samples. Rapid diagnosis of Escherichia coli (E. coli), Salmonella and Vibrio cholera pathogens can be done with simultaneously in a single multiplex PCR assay by using specific primers with adjusted PCR conditions. Through this approach, the results represented with out of 31 blood samples 1-15 shows the positive with E. coli and remaining 14 only 11 were correlated with multiplex results of Vibrio cholera, remaining the urine samples all are positive with 17 samples correlate with the Salmonella typhi. Through the high specificity benefits of excellent sensitivity, with high resolution and reproducibility. This method of results proved and illustrates the best potential system for diagnosing the infectious disease with modern trendy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Timeliness of Surveillance during Outbreak of Shiga Toxin–producing Escherichia coli Infection, Germany, 2011

PubMed Central

Wadl, Maria; Altmann, Doris; Benzler, Justus; Eckmanns, Tim; Krause, Gérard; Spode, Anke; an der Heiden, Matthias

2011-01-01

In the context of a large outbreak of Shiga toxin–producing Escherichia coli O104:H4 in Germany, we quantified the timeliness of the German surveillance system for hemolytic uremic syndrome and Shiga toxin–producing E. coli notifiable diseases during 2003–2011. Although reporting occurred faster than required by law, potential for improvement exists at all levels of the information chain. PMID:22000368

Management of bacteriuria in pregnancy.

PubMed

Pedler, S J; Bint, A J

1987-04-01

Bacteriuria of pregnancy is a common condition which, although usually asymptomatic, may give rise to potentially serious sequelae. All pregnant women should therefore be screened for the presence of bacteriuria, which if detected should be treated with an antimicrobial agent believed to be safe for use in pregnancy. Appropriate antimicrobial drugs include penicillins, cephalosporins and nitrofurantoin. Nalidixic acid, aminoglycosides and sulphonamides may be used under certain circumstances and with some precautions. Tetracyclines, trimethoprim and co-trimoxazole (trimethoprim-sulphamethoxazole) should be avoided. There is some evidence that short-course therapy in pregnant women is less effective than longer courses, and we continue to recommend a 7-day course. Follow-up after completing a treatment course is an essential part of managing bacteriuria of pregnancy.

Engineering Escherichia coli coculture systems for the production of biochemical products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Haoran; Pereira, Brian; Li, Zhengjun

Engineering microbial consortia to express complex biosynthetic pathways efficiently for the production of valuable compounds is a promising approach for metabolic engineering and synthetic biology. Here, we report the design, optimization, and scale-up of an Escherichia coli-E. coli coculture that successfully overcomes fundamental microbial production limitations, such as high-level intermediate secretion and low-efficiency sugar mixture utilization. For the production of the important chemical cis,cis-muconic acid, we show that the coculture approach achieves a production yield of 0.35 g/g from a glucose/xylose mixture, which is significantly higher than reported in previous reports. Furthermore, by efficiently producing another compound, 4-hydroxybenzoic acid, wemore » also demonstrate that the approach is generally applicable for biosynthesis of other important industrial products.« less

Engineering Escherichia coli coculture systems for the production of biochemical products

DOE PAGES

Zhang, Haoran; Pereira, Brian; Li, Zhengjun; ...

2015-06-25

Engineering microbial consortia to express complex biosynthetic pathways efficiently for the production of valuable compounds is a promising approach for metabolic engineering and synthetic biology. Here, we report the design, optimization, and scale-up of an Escherichia coli-E. coli coculture that successfully overcomes fundamental microbial production limitations, such as high-level intermediate secretion and low-efficiency sugar mixture utilization. For the production of the important chemical cis,cis-muconic acid, we show that the coculture approach achieves a production yield of 0.35 g/g from a glucose/xylose mixture, which is significantly higher than reported in previous reports. Furthermore, by efficiently producing another compound, 4-hydroxybenzoic acid, wemore » also demonstrate that the approach is generally applicable for biosynthesis of other important industrial products.« less

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

USGS Publications Warehouse

Heuvel, A.V.; McDermott, C.; Pillsbury, R.; Sandrin, T.; Kinzelman, J.; Ferguson, J.; Sadowsky, M.; Byappanahalli, M.; Whitman, R.; Kleinheinz, G.T.

2010-01-01

A linkage between Cladophora mats and exceedances of recreational water quality criteria has been suggested, but not directly studied. Th is 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 < 0.001). Below mat E. coli increased as the stranded mats persisted at the beach swash zone. Water adjacent to Cladophora mats had lower E. coli concentrations, but surpassed EPA swimming criteria the majority of sampling days. A signifi cant positive association was found between E. coli concentrations attached to Cladophora and in underlying water (p < 0.001). The attached E. coli likely acted as a reservoir for populating water underlying the mat. Fecal bacterial pathogens, however, could not be detected by microbiological culture methods either attached to mat biomass or in underlying water. Removal of 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. Copyright ?? 2010 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Protective effects of indigenous Escherichia coli against a pathogenic E. coli challenge strain in pigs.

PubMed

Vahjen, W; Cuisiniere, T; Zentek, J

2017-10-13

To investigate the inhibitory effect of indigenous enterobacteria on pathogenic Escherichia coli, a challenge trial with postweaning pigs was conducted. A pathogenic E. coli strain was administered to all animals and their health was closely monitored thereafter. Faecal samples were taken from three healthy and three diarrhoeic animals. Samples were cultivated on MacConkey agar and isolates were subcultured. A soft agar overlay assay was used to determine the inhibitory activity of the isolates. A total of 1,173 enterobacterial isolates were screened for their ability to inhibit the E. coli challenge strain. Colony forming units of enterobacteria on MacConkey agar were not different between healthy and diarrhoeic animals in the original samples. Furthermore, numbers of isolates per animal were also not significantly different between healthy (482 isolates) and diarrhoeic animals (691 isolates). A total of 43 isolates (3.7%) with inhibitory activity against the pathogenic E. coli challenge strain were detected. All inhibitory isolates were identified as E. coli via MALDI-TOF. The isolates belonged to the phylotypes A, C and E. Many isolates (67.4%) were commensal E. coli without relevant porcine pathogenic factors, but toxin- and fimbrial genes (stx2e, fae, estIb, elt1a, fas, fan) were detected in 14 inhibitory isolates. Healthy animals showed significantly (P=0.003) more inhibitory isolates (36 of 482 isolates; 7.5%) than diseased animals (7 of 691 isolates; 1.0%). There were no significant correlations regarding phylotype or pathogenic factors between healthy and diseased animals. This study has shown that a small proportion of indigenous E. coli is able to inhibit in vitro growth of a pathogenic E. coli strain in pigs. Furthermore, healthy animals possess significantly more inhibitory E. coli strains than diarrhoeic animals. The inhibition of pathogenic E. coli by specific indigenous E. coli strains may be an underlying principle for the containment of pathogenic

Escherichia coli K1-induced cytopathogenicity of human brain microvascular endothelial cells.

PubMed

Khan, Naveed Ahmed; Iqbal, Junaid; Siddiqui, Ruqaiyyah

2012-01-01

Pathophysiology of Escherichia coli sepsis is complex involving circulating bacterial products, cytokine release, and sustained bacteremia resulting in the damage of vascular endothelium. Here, it is shown that E. coli K1 produced cytopathogenicity of human brain microvascular endothelial cells (HBMEC), that constitute the blood-brain barrier. Whole bacteria or their conditioned medium produced severe HBMEC damage suggesting E. coli K1-cytopathogenicity is a contact-independent process. Using lipopolysaccharide (LPS) inhibitor, polymyxin B, purified LPS extracted from E. coli K1 as well as LPS mutant derived from E. coli K1, we showed that LPS is not the sole determinant of E. coli K1-mediated HBMEC death. Bacterial product(s) for HBMEC cytopathogenicity was heat-labile suggesting LPS-associated proteins. Several isogenic gene-deletion mutants (ΔompA, ΔibeA, ΔibeB, Δcnf1) exhibited HBMEC cytopathogenicity similar to that produced by wild type E. coli K1. E. coli K1-mediated HBMEC death was independent of phosphatidylinositol 3-kinase (PI3K) but dependent partially on focal adhesion kinase (FAK) using HBMEC expressing dominant negative FAK and PI3K. Copyright © 2012 Elsevier Ltd. All rights reserved.

Sequential UV- and chlorine-based disinfection to mitigate Escherichia coli in drinking water biofilms.

PubMed

Murphy, H M; Payne, S J; Gagnon, G A

2008-04-01

This study was designed to examine the potential downstream benefits of sequential disinfection to control the persistence of Escherichia coli under conditions relevant to drinking water distribution systems. Eight annular reactors (four polycarbonate and four cast iron) were setup in parallel to address various factors that could influence biofilm growth in distribution systems. Eight reactors were treated with chlorine, chlorine dioxide and monochloramine alone or in combination with UV to examine the effects on Escherichia coli growth and persistence in both the effluent and biofilm. In general, UV-treated systems in combination with chlorine or chlorine dioxide and monochloramine achieved greater log reductions in both effluent and biofilm than systems treated with chlorine-based disinfectants alone. However, during UV-low chlorine disinfection, E. coli was found to persist at low levels, suggesting that the UV treatment had instigated an adaptive mutation. During UV-chlorine-dioxide treatment, the E. coli that was initially below the detection limit reappeared during a low level of disinfection (0.2 mg/L) in the cast iron systems. Chloramine was shown to be effective in disinfecting suspended E. coli in the effluent but was unable to reduce biofilm counts to below the detection limit. Issues such as repair mechanism of E. coli and nitrification could help explain some of these aberrations. Improved understanding of the ability of chlorine-based disinfectant in combination with UV to provide sufficient disinfection will ultimately effect in improved management and safety of drinking water.

Occurrence of antimicrobial-resistant Escherichia coli and Salmonella enterica in the beef cattle production and processing continuum

USDA-ARS?s Scientific Manuscript database

Specific concerns have been raised that 3rd-generation cephalosporin-resistant (3GCr) Escherichia coli, trimethoprim-sulfamethoxazole-resistant (COTr) E. coli, 3GCr Salmonella enterica, and nalidixic acid-resistant (NALr) S. enterica, may be present in cattle production environments, persist through...

Disulfide Bond Formation and Activation of Escherichia coli β-Galactosidase under Oxidizing Conditions

PubMed Central

Seras-Franzoso, Joaquin; Affentranger, Roman; Ferrer-Navarro, Mario; Daura, Xavier; Villaverde, Antonio

2012-01-01

Escherichia coli β-galactosidase is probably the most widely used reporter enzyme in molecular biology, cell biology, and biotechnology because of the easy detection of its activity. Its large size and tetrameric structure make this bacterial protein an interesting model for crystallographic studies and atomic mapping. In the present study, we investigate a version of Escherichia coli β-galactosidase produced under oxidizing conditions, in the cytoplasm of an Origami strain. Our data prove the activation of this microbial enzyme under oxidizing conditions and clearly show the occurrence of a disulfide bond in the β-galactosidase structure. Additionally, the formation of this disulfide bond is supported by the analysis of a homology model of the protein that indicates that two cysteines located in the vicinity of the catalytic center are sufficiently close for disulfide bond formation. PMID:22286993

Comparative genomics and transcriptomics of Escherichia coli isolates carrying virulence factors of both enteropathogenic and enterotoxigenic E. coli.

PubMed

Hazen, Tracy H; Michalski, Jane; Luo, Qingwei; Shetty, Amol C; Daugherty, Sean C; Fleckenstein, James M; Rasko, David A

2017-06-14

Escherichia coli that are capable of causing human disease are often classified into pathogenic variants (pathovars) based on their virulence gene content. However, disease-associated hybrid E. coli, containing unique combinations of multiple canonical virulence factors have also been described. Such was the case of the E. coli O104:H4 outbreak in 2011, which caused significant morbidity and mortality. Among the pathovars of diarrheagenic E. coli that cause significant human disease are the enteropathogenic E. coli (EPEC) and enterotoxigenic E. coli (ETEC). In the current study we use comparative genomics, transcriptomics, and functional studies to characterize isolates that contain virulence factors of both EPEC and ETEC. Based on phylogenomic analysis, these hybrid isolates are more genomically-related to EPEC, but appear to have acquired ETEC virulence genes. Global transcriptional analysis using RNA sequencing, demonstrated that the EPEC and ETEC virulence genes of these hybrid isolates were differentially-expressed under virulence-inducing laboratory conditions, similar to reference isolates. Immunoblot assays further verified that the virulence gene products were produced and that the T3SS effector EspB of EPEC, and heat-labile toxin of ETEC were secreted. These findings document the existence and virulence potential of an E. coli pathovar hybrid that blurs the distinction between E. coli pathovars.

Asymptomatic bacteriuria and symptomatic urinary tract infections during pregnancy.

PubMed

Macejko, Amanda M; Schaeffer, Anthony J

2007-02-01

Urinary tract infections are common complications of pregnancy; upper tract infections in particular may lead to significant morbidity for both the mother and fetus. Bacteriuria is a significant risk factor for developing pyelonephritis in pregnant women. Therefore, proper screening and treatment of bacteriuria during pregnancy is necessary to prevent complications. All women should be screened for bacteriuria in the first trimester, and women with a history of recurrent urinary tract infections or anomalies should have repeat bacteriuria screening throughout pregnancy. Treatment of bacteriuria should include 3-day therapy with appropriate antimicrobials, and women should be followed closely after treatment because recurrence may occur in up to one third of patients.

Proteomic analysis reveals protein expression differences in Escherichia coli strains associated with persistent versus transient mastitis

USDA-ARS?s Scientific Manuscript database

Escherichia coli is a leading cause of bacterial mastitis in dairy cattle. Typically this infection is transient in nature, causing an infection that lasts 2-3 days. However, in a minority of cases, E. coli has been shown to cause a persistent intramammary infection. The mechanisms that allow for...

Increased serum procalcitonin levels in pregnant patients with asymptomatic bacteriuria

PubMed Central

2013-01-01

Background Among the pregnancy urinary tract infections, asymptomatic bacteriuria (ASB) is the most common one. Untreated ASB can progress to pyelonephritis in 30-50% of the patients and can also result in prematurity in 27% of the pregnancy so it needs immediate diagnosis and treatment. In this study, we wanted to evaluate procalcitonin levels, compared to other inflammatory in pregnant women with ASB. Methods The study was designed between the period of January 2012 and February 2013 at Sakarya University School of Medicine, Department of Gynecology and Obstetrics. The study population included 30 pregnant patients with asymptomatic bacteriuria and 39 healthy pregnant controls. Results Mean age was 28 (SD, 5.5) of the study population; mean maternal weight was 70 (SD, 8) kilogram. There were no statically significant differences between the groups according to the routine biochemical parameters, but gestational age was significantly lower in the ASB group compared to the controls (20.4 vs 28.6, respectively; p < 0.001). Serum procalcitonin levels were negative in all of the controls. In ASB group, 9 (30%) patients had procalcitonin levels greater than >0.05 ng/ml and 21(70%) patients had negative procalcitonin levels (Chi-squrae, p < 0.001). The sensitivity and specificity of procalcitonin assay for ASB was calculated as 30% and 100%, respectively. The positive predictive value was 100% and the negative predictive value was 65%. The most frequent microorganisms in the urine culture were Escherichia coli (26 patients, 87%), Proteus mirabilis (3 patients, 10%) and Klebsiella (1 patient, 3%) in the ASB group. We experienced four (44%) recurrences among nine positive procalcitonin in ASB patients after completion of treatment of the first ASB diagnosis. Discussion Procalcitonin levels were significantly higher in ASB group than the control group and serum procalcitonin levels were higher in pregnant women with recurrent ASB. This finding is an important

Selective detection of Escherichia coli by imaging of the light intensity transmitted through an optical disk

NASA Astrophysics Data System (ADS)

Shiramizu, Hideyuki; Kuroda, Chiaki; Ohki, Yoshimichi; Shima, Takayuki; Wang, Xiaomin; Fujimaki, Makoto

2018-03-01

We have developed an optical disk system for imaging transmitted light from Escherichia coli dispersed on an optical disk. When E. coli was stained using Bismarck brown, the transmittance was found to decrease in images obtained at λ = 405 nm. The results indicate that transmittance imaging is suitable for finding the difference in light intensity between stained and unstained E. coli, whereas the reflectance images were scarcely changed by staining. Therefore, E. coli can be selectively discriminated from abiotic contaminants using transmittance imaging.

Phenotypic and molecular detection of BLACTX-M gene extended-spectrum beta-lactamases in escherichia coli and klebsiella pneumoniae of north sumatera isolates

NASA Astrophysics Data System (ADS)

Hasibuan, Mirzan; Suryanto, Dwi; Lia Kusumawati, R.

2018-03-01

The application of antibiotics expanded-spectrum third-generation cephalosporin for the treatment of infectious diseases in hospitals is known contribute to increasing resistance due to the presence of the blaCTX-M gene in the bacteria producing ESBLs. This study was aimed to detect ESBLs, isolate phenotype and blaCTX-M genes on Escherichia coli and Klebsiella pneumoniae collected from H. Adam Malik Central Hospital. Phenotypes of the bacterial were detection using Vitek two compact, while the blaCTX-M genes were detection using polymerase chain reaction technique. The results showed that 85 (100%) isolates were ESBLs consisted of 41(48%) of Escherichia coli, and 44 (52%) of Klebsiella pneumoniae, respectively. blaCTX-M genes were detection in 62 (72.94%) of the isolates which 31 (36.47%) were Escherichia coli, and 31 (36.47%) of the isolates were Klebsiella pneumoniae, respectively. This study indicates the high prevalence of blaCTX-M genes in Escherichia coli and Klebsiella pneumoniea causing bacterial antibiotic resistance.

KINETICS OF THE ACTION OF AMPICILLIN ON ESCHERICHIA COLI

PubMed Central

Seligman, Stephen J.; Hewitt, William L.

1963-01-01

Seligman, Stephen J. (University of California, Los Angeles) and William L. Hewitt. Kinetics of the action of ampicillin on Escherichia coli. J. Bacteriol. 85:1160–1164. 1963.—The curve of the number of viable Escherichia coli after exposure to ampicillin can be divided into three phases: a lag phase, a rapid bactericidal phase, and a slow bactericidal phase. Some of the variables affecting the magnitude of the first two of these phases were investigated. Progressive lowering of drug concentration resulted in prolongation of the lag phase and decrease in slope and extent of the rapid bactericidal phase. The production of elongated gram-negative forms and the emergence of a mutant with increased penicillinase activity complicated interpretation of the lower dose curves. With sufficient drug concentration, the length of the lag phase and the slope of the rapid bactericidal curve were independent of the size of inoculum up to 108 organisms. Varying pH revealed that maximal activity, as measured by the shortest lag phase and steepest slope of the rapid bactericidal phase, was present at slightly acid pH levels. Increasing pH resulted principally in prolongation of lag phase. With greater acidity, decrease in slope of the rapid bactericidal phase was more prominent. Cultures studied under conditions of lessened metabolic activity exhibited prolonged lag phase and decreased slope and extent of rapid bactericidal phase. PMID:14044010

Adenosine monophosphate affects competence development and plasmid DNA transformation in Escherichia coli.

PubMed

Zhang, Yan; Li, Wenhua; Wang, Liming; Shen, Ping; Xie, Zhixiong

2013-11-01

Artificial plasmid DNA transformation of Escherichia coli induced by calcium chloride is a routine technique in molecular biology and genetic engineering processes, but its mechanism has remained elusive. Because adenosine monophosphate (AMP) has been found to regulate natural transformation in Haemophilus influenza, we aimed to investigate the effects of AMP and its derivatives on E. coli transformation by treating competence with different concentrations of them. Analysis of the transformation efficiencies revealed that AMP inhibited the artificial plasmid DNA transformation of E. coli in a concentration- and time-dependent manner. Furthermore, we found that AMP had no effect on the expression of the transformed gene but that the intracellular AMP level of the competent cells rose after a 6 h treatment. These results suggested that the intracellular AMP level had an important role in E. coli transformation. And these have useful implications for the further investigation of the mechanism of E. coli transformation.

Engineering the biological conversion of methanol to specialty chemicals in Escherichia coli

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whitaker, W. Brian; Jones, J. Andrew; Bennett, R. Kyle

Methanol is an attractive substrate for biological production of chemicals and fuels. Engineering methylotrophic Escherichia coli as a platform organism for converting methanol to metabolites is desirable. Prior efforts to engineer methylotrophic E. coli were limited by methanol dehydrogenases (Mdhs) with unfavorable enzyme kinetics. We engineered E. coli to utilize methanol using a superior NAD-dependent Mdh from Bacillus stearothermophilus and ribulose monophosphate (RuMP) pathway enzymes from B. methanolicus. Using 13C-labeling, we demonstrate this E. coli strain converts methanol into biomass components. For example, the key TCA cycle intermediates, succinate and malate, exhibit labeling up to 39%, while the lower glycolyticmore » intermediate, 3-phosphoglycerate, up to 53%. Multiple carbons are labeled for each compound, demonstrating a cycling RuMP pathway for methanol assimilation to support growth. In conclusion, by incorporating the pathway to synthesize the flavanone naringenin, we demonstrate the first example of in vivo conversion of methanol into a specialty chemical in E. coli.« less

Engineering the biological conversion of methanol to specialty chemicals in Escherichia coli

DOE PAGES

Whitaker, W. Brian; Jones, J. Andrew; Bennett, R. Kyle; ...

2016-11-01

Methanol is an attractive substrate for biological production of chemicals and fuels. Engineering methylotrophic Escherichia coli as a platform organism for converting methanol to metabolites is desirable. Prior efforts to engineer methylotrophic E. coli were limited by methanol dehydrogenases (Mdhs) with unfavorable enzyme kinetics. We engineered E. coli to utilize methanol using a superior NAD-dependent Mdh from Bacillus stearothermophilus and ribulose monophosphate (RuMP) pathway enzymes from B. methanolicus. Using 13C-labeling, we demonstrate this E. coli strain converts methanol into biomass components. For example, the key TCA cycle intermediates, succinate and malate, exhibit labeling up to 39%, while the lower glycolyticmore » intermediate, 3-phosphoglycerate, up to 53%. Multiple carbons are labeled for each compound, demonstrating a cycling RuMP pathway for methanol assimilation to support growth. In conclusion, by incorporating the pathway to synthesize the flavanone naringenin, we demonstrate the first example of in vivo conversion of methanol into a specialty chemical in E. coli.« less

Adherence and virulence genes of Escherichia coli from children diarrhoea in the Brazilian Amazon.

PubMed

Benevides-Matos, Najla; Pieri, Fabio A; Penatti, Marilene; Orlandi, Patrícia P

2015-03-01

The bacterial pathogen most commonly associated with endemic forms of childhood diarrhoea is Escherichia coli . Studies of epidemiological characteristics of HEp-2 cell-adherent E. coli in diarrhoeal disease are required, particularly in developing countries. The aim of this study was evaluate the presence and significance of adherent Escherichia coli from diarrhoeal disease in children. The prevalence of LA, AA, and DA adherence patterns were determined in HEp-2 cells, the presence of virulence genes and the presence of the O serogroups in samples obtained from 470 children with acute diarrhoea and 407 controls in Porto Velho, Rondônia, Brazil. E. coli isolates were identified by PCR specific for groups of adherent E. coli . Out of 1,156 isolates obtained, 128 (11.0%) were positive for eae genes corresponding to EPEC, however only 38 (29.6%) of these amplified bfpA gene . EAEC were isolated from 164 (14.1%) samples; of those 41(25%), 32 (19%) and 16 (9.7%) amplified eagg , aggA or aafA genes, respectively and aggA was significantly associated with diarrhoea ( P = 0.00006). DAEC identified by their adhesion pattern and there were few isolates. In conclusion, EAEC was the main cause of diarrhoea in children, especially when the aggA gene was present, followed by EPEC and with a negligible presence of DAEC.

Postpartum surveillance of bacteriuria in term vaginal deliveries.

PubMed Central

Orrett, F. A.; Premanand, N.

1998-01-01

This study examined the prevalence of bacteriuria in early postpartum period after term vaginal delivery in Trinidad, West Indies. Asymptomatic bacteriuria occurred in 58 (34.5%) of 168 patients tested. The prevalence of bacteriuria was significantly higher in non-catheterized patients than in catheterized patients and occurred more commonly in patients who were 20 to 29 years old and who were primigravida rather than multigravida. Forty-four patients had a history of urinary tract infection; 18 (40.9%) of these patients had positive urine cultures. Although 10 patients had a vaginal discharge in the late third trimester, none presented with postpartum bacteriuria. Because of the high prevalence of postpartum bacteriuria and the potential to progress to pyelonephritis and chronic renal disease, quantitative urine cultures for all postnatal patients and curative treatment for all positive cultures are recommend. PMID:9549982

Characterizing Lysine Acetylation of Isocitrate Dehydrogenase in Escherichia coli.

PubMed

Venkat, Sumana; Chen, Hao; Stahman, Alleigh; Hudson, Denver; McGuire, Paige; Gan, Qinglei; Fan, Chenguang

2018-06-22

The Escherichia coli isocitrate dehydrogenase (ICDH) is one of the tricarboxylic acid cycle enzymes, playing key roles in energy production and carbon flux regulation. E. coli ICDH was the first bacterial enzyme shown to be regulated by reversible phosphorylation. However, the effect of lysine acetylation on E. coli ICDH, which has no sequence similarity with its counterparts in eukaryotes, is still unclear. Based on previous studies of E. coli acetylome and ICDH crystal structures, eight lysine residues were selected for mutational and kinetic analyses. They were replaced with acetyllysine by the genetic code expansion strategy or substituted with glutamine as a classic approach. Although acetylation decreased the overall ICDH activity, its effects were different site by site. Deacetylation tests demonstrated that the CobB deacetylase could deacetylate ICDH both in vivo and in vitro, but CobB was only specific for lysine residues at the protein surface. On the other hand, ICDH could be acetylated by acetyl-phosphate chemically in vitro. And in vivo acetylation tests indicated that the acetylation level of ICDH was correlated with the amounts of intracellular acetyl-phosphate. This study nicely complements previous proteomic studies to provide direct biochemical evidence for ICDH acetylation. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Avian Escherichia coli virulence factors associated with coli septicemia in broiler chickens].

PubMed

Ramirez Santoyo, R M; Moreno Sala, A; Almanza Marquez, Y

2001-01-01

In order to detect phenotypic characteristics associated with pathogenicity, 25 strains of Escherichia coli, isolated from clinical cases of colisepticemia in broiler chickens, were examined to determine the following properties: colicinogenicity, colicin V production, type 1 fimbriae, hemolysin expression and motility. Colicinogenicity occurred in 72% of the strains, 56% of all strains produced colicin V, 84% were positive for type 1 fimbriae and 80% were positive for motility. None of the strains had hemolytic activity; however, all of them, expressed at least one of the other characteristics studied. These results suggest that the diversity of phenotypes detected partially explain the multifactorial nature of avian colisepticemia.

No evidence for a bovine mastitis Escherichia coli pathotype.

PubMed

Leimbach, Andreas; Poehlein, Anja; Vollmers, John; Görlich, Dennis; Daniel, Rolf; Dobrindt, Ulrich

2017-05-08

Escherichia coli bovine mastitis is a disease of significant economic importance in the dairy industry. Molecular characterization of mastitis-associated E. coli (MAEC) did not result in the identification of common traits. Nevertheless, a mammary pathogenic E. coli (MPEC) pathotype has been proposed suggesting virulence traits that differentiate MAEC from commensal E. coli. The present study was designed to investigate the MPEC pathotype hypothesis by comparing the genomes of MAEC and commensal bovine E. coli. We sequenced the genomes of eight E. coli isolated from bovine mastitis cases and six fecal commensal isolates from udder-healthy cows. We analyzed the phylogenetic history of bovine E. coli genomes by supplementing this strain panel with eleven bovine-associated E. coli from public databases. The majority of the isolates originate from phylogroups A and B1, but neither MAEC nor commensal strains could be unambiguously distinguished by phylogenetic lineage. The gene content of both MAEC and commensal strains is highly diverse and dominated by their phylogenetic background. Although individual strains carry some typical E. coli virulence-associated genes, no traits important for pathogenicity could be specifically attributed to MAEC. Instead, both commensal strains and MAEC have very few gene families enriched in either pathotype. Only the aerobactin siderophore gene cluster was enriched in commensal E. coli within our strain panel. This is the first characterization of a phylogenetically diverse strain panel including several MAEC and commensal isolates. With our comparative genomics approach we could not confirm previous studies that argue for a positive selection of specific traits enabling MAEC to elicit bovine mastitis. Instead, MAEC are facultative and opportunistic pathogens recruited from the highly diverse bovine gastrointestinal microbiota. Virulence-associated genes implicated in mastitis are a by-product of commensalism with the primary function

Ecological and genetic determinants of plasmid distribution in Escherichia coli.

PubMed

Medaney, Frances; Ellis, Richard J; Raymond, Ben

2016-11-01

Bacterial plasmids are important carriers of virulence and antibiotic resistance genes. Nevertheless, little is known of the determinants of plasmid distribution in bacterial populations. Here the factors affecting the diversity and distribution of the large plasmids of Escherichia coli were explored in cattle grazing on semi-natural grassland, a set of populations with low frequencies of antibiotic resistance genes. Critically, the population genetic structure of bacterial hosts was chararacterized. This revealed structured E. coli populations with high diversity between sites and individuals but low diversity within cattle hosts. Plasmid profiles, however, varied considerably within the same E. coli genotype. Both ecological and genetic factors affected plasmid distribution: plasmid profiles were affected by site, E. coli diversity, E. coli genotype and the presence of other large plasmids. Notably 3/26 E. coli serotypes accounted for half the observed plasmid-free isolates indicating that within species variation can substantially affect carriage of the major conjugative plasmids. The observed population structure suggest that most of the opportunities for within species plasmid transfer occur between different individuals of the same genotype and support recent experimental work indicating that plasmid-host coevolution, and epistatic interactions on fitness costs are likely to be important in determining occupancy. © 2016 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

ESCHERICHIA COLI: THE BEST BIOLOGICAL DRINKING WATER INDICATOR FOR PUBLIC HEALTH PROTECTION

EPA Science Inventory

Public health protection requires an indicator of fecal pollution. It is not to analyze drinking water for all pathogens. Escherichia coli is found in all mammal feces at concentrations of 10 log 9/gram. It does not multiply appreciably in the environment. In the 1890s, it was ch...

Behavior of non-O157 Shiga toxin-producing Escherichia coli, enteroinvasive E. coli, enteropathogenic E. coli, and enterotoxigenic E. coli strains on alfalfa sprouts.

PubMed

Gómez-Aldapa, Carlos A; Rangel-Vargas, Esmeralda; Torres-Vitela, M Del Refugio; Villarruel-López, Angélica; Castro-Rosas, Javier

2013-08-01

Data about the behavior of non-O157 Shiga toxin-producing Escherichia coli (non-O157 STEC), enteroinvasive E. coli (EIEC), enterotoxigenic E. coli (ETEC), and enteropathogenic E. coli (EPEC) on seeds and alfalfa sprouts are not available. The behavior of STEC, EIEC, ETEC, and EPEC was determined during germination and sprouting of alfalfa seeds at 20 ± 2°C and 30 ± 2°C and on alfalfa sprouts at 3 ± 2°C. When alfalfa seeds were inoculated with STEC, EIEC, ETEC, or EPEC strains, all these diarrheagenic E. coli pathotypes (DEPs) grew during germination and sprouting of seeds, reaching counts of approximately 5 and 6 log CFU/g after 1 day at 20 ± 2°C and 30 ± 2°C, respectively. However, when the sprouts were inoculated after 1 day of seed germination and stored at 20 ± 2°C or 30 ± 2°C, no growth was observed for any DEP during sprouting at 20 ± 2°C or 30 ± 2°C for 9 days. Refrigeration reduced significantly (P < 0.0.5) the number of viable DEPs on sprouts after 20 days in storage; nevertheless, these decreases have no practical significance for the safety of the sprouts.

Differential decay of Enterococci and Escherichia coli originating from two fecal pollution sources

EPA Science Inventory

Using in situ subtropical aquatic mesocosms, fecal source (cattle manure versus sewage) was shown to be the most important contributor to differential loss in viability of fecal indicator bacteria (FIB), specifically enterococci in freshwater and Escherichia coli in marine habita...

Prevalence and antimicrobial resistance in Escherichia coli from food animals in Lagos, Nigeria

USDA-ARS?s Scientific Manuscript database

Foodborne bacteria are often associated with human infections; these infections can become more complicated to treat if the bacteria are also resistant to antimicrobials. In this study, prevalence, antimicrobial resistance, and genetic relatedness of Escherichia coli among food producing animals fr...

Secretome analysis of diarrhea-inducing strains of Escherichia coli

PubMed Central

Nirujogi, Raja Sekhar; Muthusamy, Babylakshmi; Kim, Min-Sik; Sathe, Gajanan J.; Lakshmi, P.T.V.; Kovbasnjuk, Olga N.; Prasad, T.S. Keshava; Wade, Mary; Jabbour, Rabih E.

2017-01-01

Secreted proteins constitute a major part of virulence factors that are responsible for pathogenesis caused by Gram-negative bacteria. Enterohemorrhagic Escherichia coli, O157:H7, is the major pathogen often causing outbreaks. However, studies have reported that the significant outbreaks caused by non-O157:H7 E. coli strains, also known as “Big-Six” serogroup strains, are increasing. There is no systematic study describing differential secreted proteins from these non-O157:H7 E. coli strains. In this study, we carried out MS-based differential secretome analysis using tandem mass tags labeling strategy of non-O157:H7 E. coli strains, O103, O111, O121, O145, O26, and O45. We identified 1241 proteins, of which 565 proteins were predicted to be secreted. We also found that 68 proteins were enriched in type III secretion system and several of them were differentially expressed across the strains. Additionally, we identified several strain-specific secreted proteins that could be used for developing potential markers for the identification and strain-level differentiation. To our knowledge, this study is the first comparative proteomic study on secretome of E. coli Big-Six serogroup and the several of these strain-specific secreted proteins can be further studied to develop potential markers for identification and strain-level differentiation. Moreover, the results of this study can be utilized in several applications, including food safety, diagnostics of E. coli outbreaks, and detection and identification of bio threats in biodefense. PMID:28070933

Asymptomatic bacteriuria: review and discussion of the IDSA guidelines.

PubMed

Nicolle, Lindsay E

2006-08-01

Asymptomatic bacteriuria is a common finding, but is usually benign. Screening and treatment of asymptomatic bacteriuria is only recommended for pregnant women, or for patients prior to selected invasive genitourinary procedures. Healthy women identified with asymptomatic bacteriuria on population screening subsequently experience more frequent episodes of symptomatic infection, but antimicrobial treatment of asymptomatic bacteriuria does not decrease the occurrence of these episodes. Clinical trials in spinal-cord injury patients, diabetic women, patients with indwelling urethral catheters, and elderly nursing home residents have consistently found no benefits with treatment of asymptomatic bacteriuria. Negative outcomes with antimicrobial treatment do occur, including adverse drug effects and re-infection with organisms of increasing resistance. Optimal management of asymptomatic bacteriuria requires appropriate implementation of screening strategies to promote timely identification of the selected patients for whom treatment is beneficial, and avoidance of antimicrobial therapy where no benefit has been shown.

Escherichia coli yjjPB genes encode a succinate transporter important for succinate production.

PubMed

Fukui, Keita; Nanatani, Kei; Hara, Yoshihiko; Yamakami, Suguru; Yahagi, Daiki; Chinen, Akito; Tokura, Mitsunori; Abe, Keietsu

2017-09-01

Under anaerobic conditions, Escherichia coli produces succinate from glucose via the reductive tricarboxylic acid cycle. To date, however, no genes encoding succinate exporters have been established in E. coli. Therefore, we attempted to identify genes encoding succinate exporters by screening an E. coli MG1655 genome library. We identified the yjjPB genes as candidates encoding a succinate transporter, which enhanced succinate production in Pantoea ananatis under aerobic conditions. A complementation assay conducted in Corynebacterium glutamicum strain AJ110655ΔsucE1 demonstrated that both YjjP and YjjB are required for the restoration of succinate production. Furthermore, deletion of yjjPB decreased succinate production in E. coli by 70% under anaerobic conditions. Taken together, these results suggest that YjjPB constitutes a succinate transporter in E. coli and that the products of both genes are required for succinate export.

Black soldier fly (Diptera: Stratiomyidae) larvae reduce Escherichia coli in dairy manure.

PubMed

Liu, Qiaolin; Tomberlin, Jeffery K; Brady, Jeff A; Sanford, Michelle R; Yu, Ziniu

2008-12-01

Escherichia coli labeled with a green fluorescent protein was inoculated into sterile dairy manure at 7.0 log cfu/g. Approximately 125 black soldier fly larvae were placed in manure inoculated and homogenized with E. coli. Manure inoculated with E. coli but without black soldier fly larvae served as the control. For the first experiment, larvae were introduced into 50, 75, 100, or 125 g sterilized dairy manure inoculated and homogenized with E. coli and stored 72 h at 27 degrees C. Black soldier fly larvae significantly reduced E. coli counts in all treatments. However, varying the amount of manure provided the black soldier fly larvae significantly affected their weight gain and their ability to reduce E. coli populations present. For the second experiment, larvae were introduced into 50 g manure inoculated with E. coli and stored for 72 h at 23, 27, 31, or 35 degrees C. Minimal bacterial growth was recorded in the control held at 35 degrees C and was excluded from the analysis. Black soldier fly larvae significantly reduced E. coli counts in manure held at remaining temperatures. Accordingly, temperature significantly influenced the ability of black soldier fly larvae to develop and reduce E. coli counts with greatest suppression occurring at 27 degrees C.

Genetically engineered Escherichia coli FBR5: Part II. Ethanol production from xylose and simultaneous product recovery

USDA-ARS?s Scientific Manuscript database

In these studies concentrated xylose solution was fermented to ethanol employing Escherichia coli FBR5 which can ferment both lignocellulosic sugars (hexoses and pentoses). E. coli FBR5 can produce 40-50 gL-1 ethanol from 100 gL-1 xylose in batch reactors. Increasing sugar concentration beyond this...

Whole-genome sequence of Escherichia coli serotype O157:H7 strain EDL932 (ATCC 43894)