scholarly journals Host Immune Status Influences the Development of Attaching and Effacing Lesions in Weaned Pigs

2005 ◽  
Vol 73 (9) ◽  
pp. 5514-5523 ◽  
Author(s):  
Francis Girard ◽  
Isabelle P. Oswald ◽  
Ionélia Taranu ◽  
Pierre Hélie ◽  
Greg D. Appleyard ◽  
...  
Keyword(s):  
Body Weight ◽  
Immune Status ◽  
Natural Resistance ◽  
Weaned Pigs ◽  
Challenge Strain ◽  
E Coli ◽  
Newborn Piglets ◽  
Reverse Transcription Pcr ◽  
Naturally Occurring

ABSTRACT Attaching and effacing Escherichia coli (AEEC) has been associated with naturally occurring attaching and effacing (A/E) lesions in weaned pigs, and although A/E lesions have been experimentally reproduced in newborn piglets, such lesions have been much more difficult to induce in older conventional pigs. Hence, the aim of this study was to examine the effect of oral administration of dexamethasone on the development of A/E lesions in weaned pigs challenged with a porcine enteropathogenic E. coli (PEPEC) strain and to investigate the involvement of local intestinal cytokine response. Dexamethasone, given orally at a dosage of 3 mg kg of body weight−1, significantly enhanced both the colonization of the challenge strain and the prevalence of foci of intimately adherent bacteria, resulting in extensive A/E lesions in the ileum, cecum, and colon of challenged pigs. We also confirmed the expression of both intimin and Tir by PEPEC strain ECL1001 in A/E lesions in vivo, which is, to our knowledge, the first report of the involvement of the latter proteins in any AEEC infections in vivo. Moreover, semiquantitative reverse transcription-PCR demonstrated that interleukin 1β (IL-1β), IL-6, IL-8, and, to a lesser extent, IL-12p40 are significantly upregulated in the ileum following challenge with strain ECL1001, whereas dexamethasone blocks such upregulation. Taken together, our results strongly suggested that host immune status influences the development of A/E lesions in weaned pigs, and it appears that IL-1β, IL-6, IL-8, and, to a lesser extent, IL-12p40 are expressed during infection of weaned pigs by PEPEC and may contribute to the natural resistance of the host against PEPEC infection.

scholarly journals Effects ofibeADeletion on Virulence and Biofilm Formation of Avian PathogenicEscherichia coli

2010 ◽  
Vol 79 (1) ◽  
pp. 279-287 ◽  
Author(s):  
Shaohui Wang ◽  
Chunling Niu ◽  
Zhenyu Shi ◽  
Yongjie Xia ◽  
Muhammad Yaqoob ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Wild Type Strain ◽  
Chicken Embryo Fibroblast ◽  
Neonatal Meningitis ◽  
Pcr Analysis ◽  
E Coli ◽  
Reverse Transcription Pcr ◽  
Animal System ◽  
The Brain

ABSTRACTTheibeAgene is located on a genomic island, GimA, which is involved in the pathogenesis of neonatal meningitisEscherichia coli(NMEC) and avian pathogenicE. coli(APEC). The prevalence ofibeAin the APEC collection in China was investigated, and 20 of 467 strains (4.3%) were positive. In addition, analysis of the association of theE. colireference (ECOR) groups with positive strains revealed thatibeAwas linked to group B2. TheibeAgene in DE205B was analyzed and compared to those of APEC and NMEC, which indicated that the specificity ofibeAwas not consistent along pathotypes. The invasion of chicken embryo fibroblast DF-1 cells by APEC DE205B and RS218 was observed, which suggested that DF-1 cells could be a model to study the mechanism of APEC invasion. The inactivation ofibeAin APEC DE205B led to the reduced capacity to invade DF-1 cells, defective virulencein vivo, and decreased biofilm formation compared to the wild-type strain. In addition, strain AAEC189 expressingibeAexhibited enhanced invasion capacity and biofilm formation. The results of the quantitative real-time reverse transcription-PCR (qRT-PCR) analysis and animal system infection experiments indicated that the loss ofibeAdecreased the colonization and proliferation capacities of APEC in the brain during system infection.

scholarly journals ANTI DIARRHEA EFFECT OF ETHANOL EXTRACT KECAPI BARK (SANDORICUM KOETJAPE MERR) ON MALE GUINEA PIG INDUCED WITH CASTOR OIL AND BACTERIA ESCHERICHIA COLI

2018 ◽  
Vol 11 (13) ◽  
pp. 73
Author(s):  
Eva Diansari ◽  
Edy Suwarso ◽  
Aminah Dalimunthe
Keyword(s):  
Escherichia Coli ◽  
Body Weight ◽  
Guinea Pig ◽  
Castor Oil ◽  
Ethanol Extract ◽  
Stem Bark ◽  
Start Time ◽  
E Coli ◽  
Sandoricum Koetjape

Objective: Kecapi bark (Sandoricum koetjape Merr.) is a plant of the Meliaceae family that is often used by people to treat diarrhea and abdominal pain. This study aims to determine the effects of antidiarrheal from the ethanol extract of the Kecapi stem bark on induced with castor oil and bacteria Escherichia coli.Methods: Before the in vivo on male guinea pig test was switched first, then 10 ml of castor oil was induced and 7.7 ml of E. coli male guinea pig was induced, then each male guinea was given a variation of dose ethanol extract kecapi stem bark and loperamide as the comparison. Parameters measured in this study were the start time of diarrhea, consistency of feces, frequency, and duration of diarrhea.Result: The results obtained showed that ethanol extract of kecapi bark antidiarrheal effect on guinea pigs induced castor oil (dose of 800 mg/kg body weight) and E. coli.Conclusion: Ethanol extract of Kecapi bark has an activity of antidiarrheal..

scholarly journals In-vivo Effect of Probiotics on Escherichia coli O157:H7 Isolated from Salad Vegetables

2012 ◽  
Vol 1 (4) ◽  
pp. 27 ◽  
Author(s):  
Roseline Ekiomado Uzeh ◽  
Chinwe Amaka Okolo ◽  
Bamidele Abiodun Iwalokun
Keyword(s):  
Escherichia Coli ◽  
Body Weight ◽  
Good Health ◽  
Lymphoid Hyperplasia ◽  
Green Beans ◽  
Street Vendors ◽  
Green Pepper ◽  
E Coli ◽  
Salad Vegetables

<p>This study was undertaken to isolate <em>Escherichia coli </em>O157:H7 from salad vegetables, determine its pathogenicity and effect on the gastrointestinal tract of mice and sensitivity to probiotics; <em>Lactobacillus lactis </em>ATCC12315 and <em>Lactobacillus acidophilus </em>ATCC4356 in-vivo. Twenty seven samples made up of eight different types of salad vegetables which includes carrot, cabbage, cucumber, lettuce, peas, green pepper, green beans and spring onions were collected from different locations; markets, farm and street vendors in Lagos, Nigeria. Sampling was done between 13<sup>th</sup> October 2009 and 17<sup>th</sup> March 2010. In all experiments with mice the protocol for care of animal was carried out according to National Institute of Health (NIH). The mice given only <em>E. coli </em>O157:H7 developed diarrhea which led to loss of body weight and death of majority of them. On the other hand mice that were not given any microbial suspension (control), those given only probiotics, combination of <em>E. coli</em> O157:H7 and probiotics showed no symptom of diarrhea and there was increase in their body weight. The histopathology of the intestines of this group of mice showed that their intestines were not damaged, while those given only <em>E. coli</em> O157:H7 showed lymphoid hyperplasia, mucosal sloughing and inflammation (enteritis). The maintenance of good health by probiotics has again been re-emphasized.</p>

scholarly journals In Vivo Selection of Reduced Susceptibility to Carbapenems in Acinetobacter baumannii Related to ISAba1-Mediated Overexpression of the Natural blaOXA-66 Oxacillinase Gene

2009 ◽  
Vol 53 (6) ◽  
pp. 2657-2659 ◽  
Author(s):  
Samy Figueiredo ◽  
Laurent Poirel ◽  
Jacques Croize ◽  
Christine Recule ◽  
Patrice Nordmann
Keyword(s):  
Acinetobacter Baumannii ◽  
Reverse Transcription ◽  
Resistance Pattern ◽  
Pcr Analysis ◽  
In Vivo Selection ◽  
Reverse Transcription Pcr ◽  
Naturally Occurring ◽  
Carbapenemase Gene ◽  
Selection Of

ABSTRACT Two clonally related Acinetobacter baumannii isolates, A1 and A2, were obtained from the same patient. Isolate A2, selected after an imipenem-containing treatment, showed reduced susceptibility to carbapenems. This resistance pattern was related to insertion of the ISAba1 element upstream of the naturally occurring bla OXA-66 carbapenemase gene as demonstrated by sequencing, reverse transcription-PCR analysis, and inactivation of the bla OXA-66 gene.

scholarly journals In Vivo Expression of the β-Glucoside (bgl) Operon of Escherichia coli Occurs in Mouse Liver

1998 ◽  
Vol 180 (17) ◽  
pp. 4746-4749 ◽  
Author(s):  
M. Ayub Khan ◽  
Richard E. Isaacson
Keyword(s):  
Escherichia Coli ◽  
Infected Mouse ◽  
Mouse Liver ◽  
Transcription Terminator ◽  
E Coli ◽  
Reverse Transcription Pcr ◽  
Bacterial Clone ◽  
Chloramphenicol Acetyltransferase Gene

ABSTRACT An Escherichia coli DNA fragment was identified that contained part of the β-glucoside (bgl) operon. This fragment was identified because it contained a promoter that was responsible for the expression of a reporter gene, the chloramphenicol acetyltransferase gene, in a mouse liver during bacterial infection but not when a bacterial clone was grown in vitro. This fragment contained a promoter and a rho-independent transcription terminator which were flanked by the 3′ end of bglG and the 5′ end ofbglF. Reverse transcription-PCR confirmed thatcat-specific mRNA was produced in infected mouse liver but not in vitro. mRNA encoding the positive regulator of thebgl operon, bglG, also was detected in mouse liver infected with an E. coli strain. These results demonstrated that expression of the bgl operon occurs in infected mouse liver and suggests a unique role for this operon in vivo.

scholarly journals Inhibition of isoleucyl-transfer ribonucleic acid synthetase in Echerichia coli by pseudomonic acid

1978 ◽  
Vol 176 (1) ◽  
pp. 305-318 ◽  
Author(s):  
Julia Hughes ◽  
Graham Mellows
Keyword(s):  
Rna Synthesis ◽  
Inhibitory Effect ◽  
Trna Synthetase ◽  
Threonine Deaminase ◽  
Trna Synthetases ◽  
E Coli ◽  
Naturally Occurring ◽  
Pseudomonic Acid

The mode of action of the antibiotic pseudomonic acid has been studied in Escherichia coli. Pseudomonic acid strongly inhibits protein and RNA synthesis in vivo. The antibiotic had no effect on highly purified DNA-dependent RNA polymerase and showed only a weak inhibitory effect on a poly(U)-directed polyphenylalanine-forming ribosomal preparation. Chloramphenicol reversed inhibition of RNA synthesis in vivo. Pseudomonic acid had little effect on RNA synthesis in a regulatory mutant, E. coli B AS19 RCrel, whereas protein synthesis was strongly inhibited. In pseudomonic acid-treated cells, increased concentrations of ppGpp, pppGpp and ATP were observed, but the GTP pool size decreased, suggesting that inhibition of RNA synthesis is a consequence of the stringent control mechanism imposed by pseudomonic acid-induced deprivation of an amino acid. Of the 20 common amino acids, only isoleucine reversed the inhibitory effect in vivo. The antibiotic was found to be a powerful inhibitor of isoleucyl-tRNA synthetase both in vivo and in vitro. Of seven other tRNA synthetases assayed, only a weak inhibitory effect on phenylalanyl-tRNA synthetase was observed; this presumably accounted for the weak effect on polyphenylalanine formation in a ribosomal preparation. Pseudomonic acid also significantly de-repressed threonine deaminase and transaminase B activity, but not dihydroxyacid dehydratase (isoleucine-biosynthetic enzymes) by decreasing the supply of aminoacylated tRNAIle. Pseudomonic acid is the second naturally occurring inhibitor of bacterial isoleucyl-tRNA synthetase to be discovered, furanomycin being the first.

scholarly journals Effect of the Addition of Magnesium Salt to a Feed Mixture on Intestinal Microflora, Health, and Production of Sows

2013 ◽  
Vol 57 (1) ◽  
pp. 69-72 ◽  
Author(s):  
Beata Trawńska ◽  
Antoni Polonis ◽  
Jerzy Lechowski ◽  
Leszek Tymczyna ◽  
Ryszard Borowski ◽  
...  
Keyword(s):  
Body Weight ◽  
Survival Rate ◽  
Reproductive Performance ◽  
Intestinal Microflora ◽  
Alimentary Tract ◽  
Magnesium Salt ◽  
Control Group ◽  
Feed Mixture ◽  
E Coli ◽  
Newborn Piglets

Abstract The effect of feed mixture supplementation with MgCl2 on alimentary tract microflora, haematological markers, and selected parameters of reproductive performance of sows was investigated. The animals were divided into control group (K) and two experimental groups (E1 and E2). The sows from the experimental groups were receiving 1 g of MgCl2 6H20/100 kg b.w./day, which constituted 120 mg of pure magnesium, administered in a small portion of a feed mixture. The sows from group E1 were receiving MgCl2 every day for 30 d, whereas sows from group E2 for 60 d. A significant decrease in the count of E. coli, Providencia sp., and Proteus sp. was noted in faeces of the swine of both experimental groups. The study has also demonstrated a reduced number of lymphocytes and an increased number of granulocytes in blood of the sows receiving MgCl2. Feeding of pregnant sows with the addition of magnesium salt decreased the mortality rate of newborn piglets, increased the survival rate of piglets until 21 d of their life, and increased body weight values of litters originating from experimental sows, compared to the litters of control sows.

scholarly journals 140 Effects of Bacillus subtilis probiotics on growth performance, diarrhea, and fecal β-hemolytic coliforms of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 79-80
Author(s):  
Yijie He ◽  
Kwangwook Kim ◽  
Cynthia Jinno ◽  
Lauren Kovanda ◽  
Seijoo Yang ◽  
...  
Keyword(s):  
Body Weight ◽  
Bacillus Subtilis ◽  
Growth Performance ◽  
Feed Efficiency ◽  
Control Diet ◽  
Positive Control ◽  
Negative Control ◽  
Enterotoxigenic Escherichia Coli ◽  
Weaned Pigs ◽  
E Coli

Abstract The objective of this experiment was to investigate the effects of Bacillus subtilis on growth performance, diarrhea and fecal β-hemolytic coliforms of weaned pigs experimentally infected with a strain of E. coli (F18, express genes of LT, STb, and SLT 2 toxins). Weaned pigs (n = 48, 6.17 ± 0.36 kg BW) were individually housed in disease containment rooms and randomly allotted to one of four dietary treatments: negative control (NC, control diet without E. coli challenge), positive control (PC, control diet with E. coli challenge), and supplementation of 50 mg/kg of carbadox or 500 mg/kg of Bacillus subtilis probiotics. The experiment lasted 28 d with 7 d before and 21 d after the first E. coli inoculation. The F18 E. coli were given to pigs at 1010 CFU/3 mL dose for three consecutive d. Diarrhea score was daily recorded for each pig to calculate frequency of diarrhea. Fecal samples were collected on d 0, 3, 7, 14, and 21 PI to analyze β-hemolytic coliforms. Data were analyzed using the Mixed Procedure of SAS. Pigs supplemented with carbadox had greater (P < 0.05) body weight on d 7, 14, and 21 PI than pigs in the PC and probiotics group. Supplementation of probiotics enhanced pig body weight on d 21 PI, compared with the PC. E. coli challenge reduced (P < 0.05) ADG and feed efficiency from d 0 to 21 PI, while supplementation of antibiotics or probiotics enhanced ADG and feed efficiency from d 0 to 21 PI. Pigs in carbadox and probiotics groups had reduced (P < 0.05) frequency of diarrhea throughout the experiment and fecal β-hemolytic coliforms on d 7 PI than pigs in the PC. In conclusion, supplementation of Bacillus subtilis could enhance disease resistance and promote growth performance of weaned pigs under disease challenge condition.

scholarly journals Digitalizing heterologous gene expression in Gram-negative bacteria with a portable on/off module

2019 ◽  
Author(s):  
Belén Calles ◽  
Angel Goñi-Moreno ◽  
Víctor de Lorenzo
Keyword(s):  
Heterologous Gene Expression ◽  
Host Bacterium ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Inducible Promoters ◽  
E Coli ◽  
Naturally Occurring ◽  
Conditional Expression ◽  
Colicin E3

ABSTRACTWhile prokaryotic promoters controlled by signal-responding regulators typically display a range of input/output ratios when exposed to cognate inducers, virtually no naturally occurring cases are known to have an off state of zero transcription—as ideally needed for synthetic circuits. To overcome this problem we have modelled and implemented simple digitalizer module that completely suppresses the basal level of otherwise strong promoters in such a way that expression in the absence of induction is entirely impeded. The circuit involves the interplay of a translation-inhibitory sRNA with the translational coupling of the gene of interest to a repressor such as LacI. The digitalizer module was validated with the strong inducible promoters Pm (induced by XylS in the presence of benzoate) and PalkB (induced by AlkS/dicyclopropylketone) and shown to perform effectively both in E. coli and the soil bacterium Pseudomonas putida. The distinct expression architecture allowed cloning and conditional expression of e.g. colicin E3, one molecule of which per cell suffices to kill the host bacterium. Revertants that escaped ColE3 killing were not found in hosts devoid of insertion sequences, suggesting that mobile elements are a major source of circuit inactivation in vivo.

scholarly journals Nramp1 Is Not a Major Determinant in the Control of Brucella melitensis Infection in Mice

2003 ◽  
Vol 71 (2) ◽  
pp. 621-628 ◽  
Author(s):  
Laurence A. Guilloteau ◽  
Jacques Dornand ◽  
Antoine Gross ◽  
Michel Olivier ◽  
Fabienne Cortade ◽  
...  
Keyword(s):  
Brucella Melitensis ◽  
Natural Resistance ◽  
Interleukin 12 ◽  
Necrosis Factor Alpha ◽  
Reverse Transcription Pcr ◽  
Tnf Α ◽  
Ifn Γ ◽  
Oxide Synthase

ABSTRACT Brucella, the causative agent of brucellosis in animals and humans, can survive and proliferate within macrophages. Macrophages mediate mouse resistance to various pathogens through the expression of the Nramp1 gene. The role of this gene in the control of Brucella infection was investigated. When BALB/c mice (Nramp1s ) and C.CB congenic mice (Nramp1r ) were infected with Brucella melitensis, the number of Brucella organisms per spleen was significantly larger in the C.CB mice than in the BALB/c mice during the first week postinfection (p.i.). This Nramp1-linked susceptibility to Brucella was temporary, since similar numbers of Brucella were recovered from the two strains of mice 2 weeks p.i. The effect of Nramp1 expression occurred within splenocytes intracellularly infected by Brucella. However, there was no difference between in vitro replication rates of Brucella in macrophages isolated from the two strains of mice infected in vivo or in Nramp1 RAW264 transfectants. In mice, infection with Brucella induced an inflammatory response, resulting in splenomegaly and recruitment of phagocytes in the spleen, which was amplified in C.CB mice. Reverse transcription-PCR (RT-PCR), performed 5 days p.i., showed that inducible nitric oxide synthase, tumor necrosis factor alpha (TNF-α), interleukin-12 p40 (IL-12p40), gamma interferon (IFN-γ), and IL-10 mRNAs were similarly induced in spleens of the two strains. In contrast, the mRNA of KC, a C-X-C chemokine, was induced only in infected C.CB mice at this time. This pattern of mRNA expression was maintained at 14 days p.i., with IFN-γ and IL-12p40 mRNAs being more intensively induced in the infected C.CB mice, but TNF-α mRNA was no longer induced. The higher recruitment of neutrophils observed in the spleens of infected C.CB mice could explain the temporary susceptibility of C.CB mice to B. melitensis infection. In contrast to infections with Salmonella, Leishmania, and Mycobacterium, the expression of the Nramp1 gene appears to be of limited importance for the natural resistance of mice to Brucella.

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