scholarly journals An Attenuated Escherichia coli K88ac LT(S63K)ΔSTb Efficiently Provides Protection Against Enterotoxigenic Escherichia coli in the Mouse Model

2021 ◽  
Vol 7 ◽  
Author(s):  
Xinyu Zhang ◽  
Shupei Yu ◽  
Darong Cheng ◽  
Yu Feng ◽  
Yuefei Yang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Wild Strain ◽  
Enterotoxigenic Escherichia Coli ◽  
Post Inoculation ◽  
Ileal Loop ◽  
E Coli ◽  
Oral Inoculation ◽  
Attenuated Isolate ◽  
Efficient Protection ◽  
Site Mutagenesis

To develop an attenuated vaccine candidate against K88ac enterotoxigenic Escherichia coli (ETEC), a novel Escherichia coli (E. coli) K88ac LT(S63K)ΔSTb with LT(S63K) mutation and ST1 deletion was generated using site mutagenesis and λ-Red homologous recombination based on wild paternal ETEC strain C83902. E. coli K88ac LT(S63K)ΔSTb showed very similar fimbriae expression and growth kinetics to the wild strain C83902, but it was significantly attenuated according to the results of a rabbit ligated ileal loop assay and mouse infection study. Oral inoculation with E. coli K88ac LT(S63K)ΔSTb stimulated the mucosa immune response and induced the secretion of IgA to K88ac in the intestines in mice. A challenge experiment revealed that the attenuated strain provided efficient protection against C83902 in the following 7 days and at the 24th day post-inoculation, suggesting that the attenuated isolate could act as an ecological protectant and vaccine in preventing K88ac ETEC.

scholarly journals 150 A bio-active, mineral-based feed additive improved growth performance and reduced severity of diarrhea in weanling pigs challenged with enterotoxigenic Escherichia coli

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 84-85
Author(s):  
Sue Sinn ◽  
Ran Song ◽  
Dana Beckler ◽  
Rob Musser ◽  
Kim Friesen
Keyword(s):  
Escherichia Coli ◽  
Growth Performance ◽  
Meta Analysis ◽  
Enterotoxigenic Escherichia Coli ◽  
Feed Additive ◽  
Post Inoculation ◽  
Adaptation Period ◽  
Weanling Pigs ◽  
Serum Samples ◽  
E Coli

Abstract A mineral-based feed additive, NutriQuest Protect™, was evaluated in five artificial Enterotoxigenic Escherichia coli (ETEC) challenge experiments to determine the effects on pig growth performance, fecal consistency and immune response. The five experiments were conducted following a similar procedure and utilized a total of 232 weanling pigs (19 d of age) assigned to one of three experimental treatments: non-challenged control (NC), challenged control (CC), and challenged pigs fed Protect at 4.0 g/kg (CP) with 36, 36, and 44 pens per treatment, respectively. Pharmacological ZnO or medications were not included in any diets. Pigs were allowed a 7-d adaptation period following weaning, orally inoculated with E. coli K88 or F18 on 0 d post-inoculation (dpi) and 1-dpi. Studies were concluded on 4-dpi. Pig BW and feed disappearance were measured on 0-dpi and 4-dpi. Serum samples were collected on 0 and 4-dpi to measure porcine proinflammatory cytokines. Fecal scores were measured daily over the challenge period. Data from the five experiments were compiled for meta-analysis using the MIXED procedure of SAS. The NC pigs had a greater ADG (0.09 vs. -0.01 kg/d, P = 0.002), ADFI (0.24 vs. 0.21 kg/d, P = 0.09), and final BW (6.8 vs. 6.5 kg, P < 0.05). Diarrhea frequency was significantly higher in CC pigs compared with pigs on CP and NC treatments (28.5 vs. 18.7 vs. 5.3%, P < 0.05). Results from the five experiments suggest that NutriQuest Protect™ improves growth performance and reduces inflammation and diarrhea in weaned pigs artificially challenged with E. coli K88 or F18.

scholarly journals Identification of a Gene within a Pathogenicity Island of Enterotoxigenic Escherichia coli H10407 Required for Maximal Secretion of the Heat-Labile Enterotoxin

2000 ◽  
Vol 68 (5) ◽  
pp. 2766-2774 ◽  
Author(s):  
James M. Fleckenstein ◽  
Luther E. Lindler ◽  
Eric A. Elsinghorst ◽  
James B. Dale
Keyword(s):  
Escherichia Coli ◽  
Pathogenicity Island ◽  
Open Reading Frames ◽  
Enterotoxigenic Escherichia Coli ◽  
Loop Model ◽  
Ileal Loop ◽  
E Coli ◽  
Link Type ◽  
Colonization Factor ◽  
Heat Labile

ABSTRACT Studies of the pathogenesis of enterotoxigenic Escherichia coli (ETEC) have largely centered on extrachromosomal determinants of virulence, in particular the plasmid-encoded heat-labile (LT) and heat-stable enterotoxins and the colonization factor antigens. ETEC causes illnesses that range from mild diarrhea to severe cholera-like disease. These differences in disease severity are not readily accounted for by our current understanding of ETEC pathogenesis. Here we demonstrate that Tia, a putative adhesin of ETECH10407 , is encoded on a large chromosomal element of approximately 46 kb that shares multiple features with previously described E. coli pathogenicity islands. Further analysis of the region downstream from tia revealed the presence of several candidate open reading frames (ORFs) in the same transcriptional orientation as tia. The putative proteins encoded by these ORFs bear multiple motifs associated with bacterial secretion apparatuses. An in-frame deletion in one candidate gene identified here as leoA (labile enterotoxin output) resulted in marked diminution of secretion of the LT enterotoxin and lack of fluid accumulation in a rabbit ileal loop model of infection. Although previous studies have suggested that E. coli lacks the capacity to secrete LT, our studies show that maximal release of LT from the periplasm of H10407 is dependent on one or more elements encoded on a pathogenicity island.

Antagonistic activity of Bacillus subtilis strains isolated from various sources

2018 ◽  
Vol 8 (2) ◽  
pp. 354-364
Author(s):  
A. N. Irkitova ◽  
A. V. Grebenshchikova ◽  
A. V. Matsyura
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Wild Strain ◽  
Fish Farming ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
E Coli ◽  
Long Period ◽  
Test Culture ◽  
Agar Media

<p>An important link in solving the problem of healthy food is the intensification of the livestock, poultry and fish farming, which is possible only in the adoption and rigorous implementation of the concept of rational feeding of animals. In the implementation of this concept required is the application of probiotic preparations. Currently, there is an increased interest in spore probiotics. In many ways, this can be explained by the fact that they use no vegetative forms of the bacilli and their spores. This property provides spore probiotics a number of advantages: they are not whimsical, easily could be selected, cultivated, and dried. Moreover, they are resistant to various factors and could remain viable during a long period. One of the most famous spore microorganisms, which are widely used in agriculture, is <em>Bacillus subtilis</em>. Among the requirements imposed to probiotic microorganisms is mandatory – antagonistic activity to pathogenic and conditional-pathogenic microflora. The article presents the results of the analysis of antagonistic activity of collection strains of <em>B. subtilis</em>, and strains isolated from commercial preparations. We studied the antagonistic activity on agar and liquid nutrient medias to trigger different antagonism mechanisms of <em>B. subtilis</em>. On agar media, we applied three diffusion methods: perpendicular bands, agar blocks, agar wells. We also applied the method of co-incubating the test culture (<em>Escherichia coli</em>) and the antagonist (or its supernatant) in the nutrient broth. Our results demonstrated that all our explored strains of <em>B. subtilis</em> have antimicrobial activity against a wild strain of <em>E. coli</em>, but to varying degrees. We identified strains of <em>B. subtilis</em> with the highest antagonistic effect that can be recommended for inclusion in microbial preparations for agriculture.</p><p><em><br /></em><em></em></p>

Bacteriophages reduce Escherichia coli O157:H7 levels in experimentally inoculated sheep

2009 ◽  
Vol 89 (2) ◽  
pp. 285-293 ◽  
Author(s):  
S J Bach ◽  
R P Johnson ◽  
K. Stanford ◽  
T A McAllister
Keyword(s):  
Escherichia Coli ◽  
Oral Administration ◽  
Coliform Bacteria ◽  
Escherichia Coli O157 ◽  
Fecal Shedding ◽  
Total Coliforms ◽  
E Coli ◽  
Oral Inoculation ◽  
Experimental Treatments ◽  
And Control

Bacteriophage biocontrol has potential as a means of mitigating the prevalence of Escherichia coli O157:H7 in ruminants. The efficacy of oral administration of bacteriophages for reducing fecal shedding of E. coli O157:H7 by sheep was evaluated using 20 Canadian Arcott rams (50.0 ± 3.0) housed in four rooms (n = 5) in a contained facility. The rams had ad libitum access to drinking water and a pelleted barley-based total mixed ration, delivered once daily. Experimental treatments consisted of administration of E. coli O157:H7 (O157), E. coli O157:H7+bacteriophages (O157+phage), bacteriophages (phage), and control (CON). Oral inoculation of the rams with 109 CFU of a mixture of four nalidixic acid-resistant strains of E. coli O157:H7 was performed on day 0. A mixture of 1010 PFU of bacteriophages P5, P8 and P11 was administered on days -2, -1, 0, 6 and 7. Fecal samples collected on 14 occasions over 21 d were analyzed for E. coli O157:H7, total E. coli, total coliforms and bacteriophages. Sheep in treatment O157+phage shed fewer (P < 0.05) E. coli O157:H7 than did sheep in treatment O157. Populations of total coliforms and total E. coli were similar (P < 0.05) among treatments, implying that bacteriophage lysis of non-target E. coli and coliform bacteria in the gastrointestinal tract did not occur. Bacteriophage numbers declined rapidly over 21 d, which likely reduced the chance of collision between bacteria and bacteriophage. Oral administration of bacteriophages reduced shedding of E. coli O157:H7 by sheep, but a delivery system that would protect bacteriophages during passage through the intestine may increase the effectiveness of this strategy as well as allow phage to be administered in the feed.Key words: Escherichia coli O157:H7, bacteriophage, sheep, environment, coliforms

scholarly journals Deletion of FaeG alleviated Enterotoxigenic Escherichia coli F4ac-induced apoptosis in the intestine

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pengpeng Xia ◽  
Yunping Wu ◽  
Siqi Lian ◽  
Guomei Quan ◽  
Yiting Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clinical Symptoms ◽  
Mucosal Damage ◽  
Enterotoxigenic Escherichia Coli ◽  
Intestinal Epithelial ◽  
Antibody Microarray ◽  
E Coli ◽  
Fimbrial Subunit ◽  
Induced Apoptosis ◽  
Weaning Piglets

AbstractEnterotoxigenic Escherichia coli (ETEC) F4ac is a major constraint to the development of the pig industry, which is causing newborn and post-weaning piglets diarrhea. Previous studies proved that FaeG is the major fimbrial subunit of F4ac E. coli and efficient for bacterial adherence and receptor recognition. Here we show that the faeG deletion attenuates both the clinical symptoms of F4ac infection and the F4ac-induced intestinal mucosal damage in piglets. Antibody microarray analysis and the detection of mRNA expression using porcine neonatal jejunal IPEC-J2 cells also determined that the absence of FaeG subunit alleviated the F4ac promoted apoptosis in the intestinal epithelial cells. Thus, targeted depletion of FaeG is still beneficial for the prevention or treatment of F4ac infection.

scholarly journals A surveillance of enteropathogens in piglets from birth to seven days of age in Brazil

2013 ◽  
Vol 33 (8) ◽  
pp. 963-969 ◽  
Author(s):  
Eduardo C. Cruz Junior ◽  
Felipe M. Salvarani ◽  
Rodrigo O.S. Silva ◽  
Marcos X. Silva ◽  
Francisco C.F. Lobato ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clostridium Difficile ◽  
Type A ◽  
Final Diagnosis ◽  
Enterotoxigenic Escherichia Coli ◽  
Microbiological Test ◽  
E Coli ◽  
Isospora Suis ◽  
Real Importance ◽  
Type C

The purpose of the study was to evaluate the real importance of anaerobic enteropathogens and rotavirus in contrast to more common agents as cause of diarrhea in piglets within the first week of life. Sixty 1- to 7-day-old piglets, 30 diarrheic and 30 non-diarrheic (control), from 15 different herds were selected, euthanized and necropsied. Samples of the jejunum, ileum, colon, cecum and feces were collected from the piglets and analyzed to determine the presence of the following enteropathogens: enterotoxigenic Escherichia coli (ETEC), Clostridium perfringens types A and C, Clostridium difficile, rotavirus and Isospora suis. Among diarrheic piglets, 23.3% were positive for C. difficile, 70% for C. perfringens type A cpb2+, 14.3% for rotavirus and 10% for ETEC. Among non-diarrheic control piglets, 10% were positive for C. difficile, 76.7% for C. perfringens type A cpb2+, 0% for rotavirus, 3.3% for ETEC and 3.3% for I. suis. C. perfringens type C was not detected in any of the animals. Histological lesions characteristic of C. difficile, E. coli and rotavirus were observed. However, no C. perfringens type A suggestive lesions were detected. There was a positive correlation between mesocolon edema and the presence of C. difficile toxins. Although C. perfringens type A cpb2+ was the most frequently detected enteropathogen, there was no association between its presence and diarrhea or macro or microscopic changes. C. difficile and Rotavirus were the most relevant pathogens involved with neonatal diarrhea in this study, and histopathology associated with microbiological test proved to be the key to reach a final diagnosis.

scholarly journals Multiplex Polymerase Chain Reaction Assay for Identification of Enterotoxigenic Escherichia Coli Strains

2001 ◽  
Vol 13 (4) ◽  
pp. 308-311 ◽  
Author(s):  
Jacek Osek
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Multiplex Polymerase Chain Reaction ◽  
Direct Determination ◽  
Enteric Bacteria ◽  
Enterotoxigenic Escherichia Coli ◽  
Chain Reaction ◽  
Gram Negative ◽  
E Coli ◽  
Polymerase Chain

A multiplex polymerase chain reaction (PCR) system was developed for identification of enterotoxigenic Escherichia coli (ETEC) strains and to differentiate them from other gram negative enteric bacteria. This test simultaneously amplifies heat-labile (LTI) and heat-stable (STI and STII) toxin sequences and the E. coli-specific universal stress protein ( uspA). The specificity of the method was validated by single PCR tests performed with the reference E. coli and non- E. coli strains and with bacteria isolated from pig feces. The multiplex PCR allowed the rapid and specific identification of enterotoxin-positive E. coli and may be used as a method for direct determination of ETEC and to differentiate them from other E. coli and gram-negative enteric isolates.

scholarly journals In Vitro and In Vivo Assessment of the Potential of Escherichia coli Phages to Treat Infections and Survive Gastric Conditions

2021 ◽  
Vol 9 (9) ◽  
pp. 1869
Author(s):  
Joanna Kaczorowska ◽  
Eoghan Casey ◽  
Gabriele A. Lugli ◽  
Marco Ventura ◽  
David J. Clarke ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Galleria Mellonella ◽  
Enterotoxigenic Escherichia Coli ◽  
E Coli ◽  
Composite Mixture ◽  
Ph Conditions ◽  
The Stability ◽  
Higher Sensitivity

Enterotoxigenic Escherichia coli (ETEC) and Shigella ssp. infections are associated with high rates of mortality, especially in infants in developing countries. Due to increasing levels of global antibiotic resistance exhibited by many pathogenic organisms, alternative strategies to combat such infections are urgently required. In this study, we evaluated the stability of five coliphages (four Myoviridae and one Siphoviridae phage) over a range of pH conditions and in simulated gastric conditions. The Myoviridae phages were stable across the range of pH 2 to 7, while the Siphoviridae phage, JK16, exhibited higher sensitivity to low pH. A composite mixture of these five phages was tested in vivo in a Galleria mellonella model. The obtained data clearly shows potential in treating E. coli infections prophylactically.

478 Dietary Butyrate and Valerate Glycerides: Effects on Growth and Systemic Immunity of Weanling Piglets Coinfected with F4 and F18 Escherichia coli

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 211-212
Author(s):  
Lauren L Kovanda ◽  
Jungjae Park ◽  
Yijie He ◽  
Sangwoo Park ◽  
Ruochen Wu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Block Design ◽  
Enterotoxigenic Escherichia Coli ◽  
Post Inoculation ◽  
Weaned Pigs ◽  
Fecal Shedding ◽  
Systemic Immunity ◽  
Randomized Complete Block Design ◽  
Potential Benefits ◽  
Weanling Piglets

Abstract Enterotoxigenic Escherichia coli (ETEC) F4 and F18 are the two most dominant pathogenic strains in weaned pigs. The objective of this experiment was to test the effects of dietary monobutyrin and monovalerin on performance and systemic immunity of weanling piglets coinfected with F4/F18 ETEC. Twenty weaned pigs (8.21 ± 1.23 kg) were individually housed and were randomly allotted to one of three diets: control (n = 6), 0.1% monobutyrin (n = 7), or 0.1% monovalerin (n = 7). The experiment was conducted 14 days, including 7 days’ adaption and 7 days post-inoculation (PI). On d 0, d 1, and d 2 PI, pigs were inoculated with 0.5 × 109 CFU/1.5 mL each of F4 and F18 ETEC for three consecutive days. Diarrhea score was recorded daily to determine frequency of diarrhea. Piglets and feeders were weighed throughout the trial to analyze growth performance. Fecal cultures from pigs on d 0, 2, and 4 PI were inspected to identify the absence or presence of hemolytic coliforms. Blood was collected on d 0, 4, and 7 PI for complete blood cells count. All data were analyzed by the Proc Mixed of SAS with randomized complete block design. Pigs supplemented with monovalerin and monobutyrin had numerically higher ADG (249 and 282 g/day) from d 0 to d 7 PI than pigs in control (198 g/day). Supplementation of monovalerin reduced (P &lt; 0.05) frequency of diarrhea throughout the experiment. Pigs fed monovalerin had lower (P &lt; 0.05) neutrophil counts on d 4 PI compared with control. Hemolytic coliforms were observed in all fecal cultures from d 2 and d 4 PI, confirming fecal shedding of ETEC. Results of this study indicate the potential benefits of monovalerin supplementation on performance and disease resistance of weaned pigs coinfected with F4 and F8 ETEC.

Detection of Enterotoxigenic Escherichia coli in Rotavirus-Infected Ghanaian Children Diagnosed with Acute Gastroenteritis

2021 ◽  
Author(s):  
Bartholomew Dzudzor ◽  
Albert Amenyedor ◽  
Vincent Amarh ◽  
George E. Armah
Keyword(s):  
Escherichia Coli ◽  
Developing Countries ◽  
Enterotoxigenic Escherichia Coli ◽  
Surveillance Study ◽  
Vaccination Program ◽  
E Coli ◽  
Rotavirus Vaccination ◽  
Stool Samples ◽  
Global Health Problem ◽  
Vaccine Surveillance

Diarrhea is a notable global health problem in several developing countries, especially in children. Prior to the introduction of the rotavirus vaccination program in Ghana, a surveillance study was conducted to investigate the prevalence of the disease caused by rotavirus in children. In this report, we re-used archival stool samples from the pre-vaccine surveillance study to provide information on prevalence of enterotoxigenic Escherichia coli in Ghanaian children. Re-analysis of the stool samples revealed co-infection of enterotoxigenic E. coli and rotavirus in 2% of the children whose samples were selected for this study. As Ghana is approaching 10 years post-implementation of the rotavirus vaccination program, the preliminary data presented in this report are a vital reference for subsequent studies aimed at ascertaining the effect of the vaccine on both rotavirus and enterotoxigenic E. coli.

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