scholarly journals Enhancement of Protective Efficacy following Intranasal Immunization with Vaccine Plus a Nontoxic LTK63 Mutant Delivered with Nanoparticles

2002 ◽  
Vol 70 (9) ◽  
pp. 4785-4790 ◽  
Author(s):  
B. C. Baudner ◽  
O. Balland ◽  
M. M. Giuliani ◽  
P. Von Hoegen ◽  
R. Rappuoli ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protective Efficacy ◽  
Vaccination Strategy ◽  
Meningococcal Vaccine ◽  
Intranasal Immunization ◽  
Mucosal Vaccination ◽  
Parenteral Immunization ◽  
Encapsulated Bacteria ◽  
Portal Of Entry ◽  
Very High

ABSTRACT Most vaccines are still given parenterally. Mucosal vaccination would offer different advantages over parenteral immunization, including blocking of the pathogens at the portal of entry. In this paper, nontoxic Escherichia coli heat-labile enterotoxin (LT) mutants and Supramolecular Biovector systems (SMBV) were evaluated in mice as mucosal adjuvants and delivery systems, respectively, for intranasal immunization with the conjugated group C meningococcal vaccine. The conjugated vaccine formulated together with the LT mutants and the SMBV induced very high titers of serum and mucosal antibodies specific for the group C meningococcal polysaccharide. This vaccination strategy also induced high titers of antibodies with bactericidal activity, which is known to correlate with efficacy. Importantly, the mucosal vaccination, but not the conventional parenteral vaccination, induced bactericidal antibodies at the mucosal level. These data strongly support the feasibility of development of intranasal vaccines with an enhanced protective efficacy against meningococci and possibly against other encapsulated bacteria.

scholarly journals Immunogenicity and protective efficacy of enterotoxigenic Escherichia coli (ETEC) total RNA against ETEC challenge in a mouse model

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mandi Liu ◽  
Yue Zhang ◽  
Di Zhang ◽  
Yun Bai ◽  
Guomei Liu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mouse Model ◽  
Immune Responses ◽  
Protective Efficacy ◽  
Enterotoxigenic Escherichia Coli ◽  
Economic Losses ◽  
Th2 Response ◽  
Total Rna ◽  
Etec Infection

AbstractEnterotoxigenic Escherichia coli (ETEC), an essential cause of post-weaning diarrhea (PWD) in piglets, leads to significant economic losses to the pig industry. The present study aims to identify the role of ETEC total RNA in eliciting immune responses to protect animals against ETEC infection. The results showed that the total RNA isolated from pig-derived ETEC K88ac strain effectively stimulated the IL-1β secretion of porcine intestinal epithelial cells (IPEC-J2). The mouse model immunized with ETEC total RNA via intramuscular injection (IM) or oral route (OR) was used to evaluate the protective efficiency of the ETEC total RNA. The results suggested that 70 μg ETEC total RNA administered by either route significantly promoted the production of the serum IL-1β and K88ac specific immunoglobulins (IgG, IgM, and IgA). Besides, the ETEC RNA administration augmented strong mucosal immunity by elevating K88ac specific IgA level in the intestinal fluid. Intramuscularly administered RNA induced a Th1/Th2 shift toward a Th2 response, while the orally administered RNA did not. The ETEC total RNA efficiently protected the animals against the ETEC challenge either by itself or as an adjuvant. The histology characterization of the small intestines also suggested the ETEC RNA administration protected the small intestinal structure against the ETEC infection. Particularly of note was that the immunity level and protective efficacy caused by ETEC RNA were dose-dependent. These findings will help understand the role of bacterial RNA in eliciting immune responses, and benefit the development of RNA-based vaccines or adjuvants.

Studies on construction of a recombinant Eimeria tenella SO7 gene expressing Escherichia coli and its protective efficacy against homologous infection

2010 ◽  
Vol 59 (4) ◽  
pp. 517-523 ◽  
Author(s):  
Guilian Yang ◽  
Chunfeng Wang ◽  
Fengqi Hao ◽  
Dan Zhao ◽  
Yunlong Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protective Efficacy ◽  
Eimeria Tenella ◽  
Gene Expressing

Expression of bacterial Rubisco genes in Escherichia coli

1986 ◽  
Vol 313 (1162) ◽  
pp. 433-445 ◽  
Keyword(s):  
Escherichia Coli ◽  
Rhodospirillum Rubrum ◽  
Active Form ◽  
Amino Acid Residues ◽  
Structural Genes ◽  
Physico Chemical ◽  
Chemical Studies ◽  
The Individual ◽  
Very High

The structural genes for three forms of Rubisco have been isolated from bacteria and introduced into various plasmids. Apart from details of the sequences which have been obtained from these constructs, they are now being exploited for mutagenesis to determine the identity and specific function of the individual amino acid residues that compose the active site. These methods have been applied to a plasmid that contains the structural gene for the simplest form of Rubisco from Rhodospirillum rubrum to obtain mutant enzymes with altered activity. The construct pRR2119 is also expressed to very high levels in Escherichia coli and enough recombinant protein of both the wild-type and m utant enzymes can be obtained for detailed physico-chemical studies. Other vectors have now been constructed, containing the genes of prokaryotic Rubisco that assemble into an active form I enzyme. The levels of expression are acceptable and the product is similar to the authentic enzyme. These constructs are now being used for mutagenesis in vitro to attempt to alter the relative rates of the oxygenase and carboxylase activities.

Analysis of p53 expression in human tumours: an antibody raised against human p53 expressed in Escherichia coli

1992 ◽  
Vol 101 (1) ◽  
pp. 183-189 ◽  
Author(s):  
C.A. Midgley ◽  
C.J. Fisher ◽  
J. Bartek ◽  
B. Vojtesek ◽  
D. Lane ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Polyclonal Antibodies ◽  
P53 Protein ◽  
Expression System ◽  
High Titre ◽  
T7 Promoter ◽  
Aberrant Expression ◽  
P53 Expression ◽  
Normal Human ◽  
Very High

A cDNA encoding the complete normal human p53 protein was expressed in Escherichia coli using an expression system based on the bacteriophage T7 promoter. The cDNA was adapted so that the full-length protein was produced without fusion to any other sequence. Large amounts of the protein were isolated and the purified protein used to produce very high titre polyclonal antibodies to p53. These new antibodies permit the sensitive detection of p53 and p53 complexes in ELISA and immunoblotting assays. Most importantly, they also permit the detection of p53 in archival tumour material that has been conventionally fixed in formalin and embedded in paraffin wax. Using this reagent we have found that aberrant expression of p53 is a frequent feature of human breast cancer. We are able to recognise six different classes of p53 expression pattern that may be of help in the subclassification of breast tumours.

A practical composite risk score for the development of Haemolytic Uraemic Syndrome from Shiga toxin-producing Escherichia coli

2019 ◽  
Vol 29 (5) ◽  
pp. 861-868 ◽  
Author(s):  
Douglas Hamilton ◽  
John Cullinan
Keyword(s):  
Escherichia Coli ◽  
High Risk ◽  
Risk Score ◽  
Shiga Toxin ◽  
Haemolytic Uraemic Syndrome ◽  
Low Risk ◽  
Medium Risk ◽  
Composite Risk ◽  
Very High ◽  
Estimation Of Risk

Abstract Background Haemolytic Uraemic Syndrome (HUS) is a serious complication of Shiga toxin-producing Escherichia coli (STEC) infection and the key reason why intensive health protection against STEC is required. However, although many potential risk factors have been identified, accurate estimation of risk of HUS from STEC remains challenging. Therefore, we aimed to develop a practical composite score to promptly estimate the risk of developing HUS from STEC. Methods This was a retrospective cohort study where data for all confirmed STEC infections in Ireland during 2013–15 were subjected to statistical analysis with respect to predicting HUS. Multivariable logistic regression was used to develop a composite risk score, segregating risk of HUS into ‘very low risk’ (0–0.4%), ‘low risk’ (0.5–0.9%), ‘medium risk’ (1.0–4.4%), ‘high risk’ (4.5–9.9%) and ‘very high risk’ (10.0% and over). Results There were 1397 STEC notifications with complete information regarding HUS, of whom 5.1% developed HUS. Young age, vomiting, bloody diarrhoea, Shiga toxin 2, infection during April to November, and infection in Eastern and North-Eastern regions of Ireland, were all statistically significant independent predictors of HUS. Demonstration of a risk gradient provided internal validity to the risk score: 0.2% in the cohort with ‘very low risk’ (1/430), 1.1% with ‘low risk’ (2/182), 2.3% with ‘medium risk’ (8/345), 3.1% with ‘high risk’ (3/98) and 22.2% with ‘very high risk’ (43/194) scores, respectively, developed HUS. Conclusion We have developed a composite risk score which may be of practical value, once externally validated, in prompt estimation of risk of HUS from STEC infection.

scholarly journals Comparison of ampicillin-sulbactam regimens simulating 1.5- and 3.0-gram doses to humans in treatment of Escherichia coli bacteremia in mice.

1995 ◽  
Vol 39 (4) ◽  
pp. 930-936 ◽  
Author(s):  
P D Lister ◽  
C C Sanders
Keyword(s):  
Escherichia Coli ◽  
Body Weight ◽  
Mouse Model ◽  
Protective Efficacy ◽  
Clinical Isolates ◽  
Human Pharmacokinetics ◽  
Beta Lactamase ◽  
E Coli ◽  
Lethal Infection ◽  
Experimentally Induced

A mouse model of bacteremia was used to compare the efficacies of 1.5- and 3.0-g intravenous doses of ampicillin-sulbactam. Seven strains of Escherichia coli producing various levels of TEM-1 beta-lactamase were used as the challenge isolates. These strains included six clinical isolates (MICs from 2/1 micrograms/ml [with 2 and 1 microgram/ml being the respective concentrations of ampicillin and sulbactam] to 32/16 micrograms/ml) with similar degrees of virulence in mice and a laboratory genetic transformant (E. coli AFE) which hyperproduces TEM-1 (MIC = 128/64 micrograms/ml). Human pharmacokinetics were simulated by injecting mice subcutaneously twice (1 h apart) with ampicillin-sulbactam at concentrations of 40 mg/kg of body weight (1.5 g) and 80 mg/kg (3.0 g). Against two clinical isolates for which ampicillin-sulbactam MICs were < or = 8/4 micrograms/ml, no difference was observed in either the rate or level of killing between the two doses, and both doses were 100% protective against lethal infection. Against the four clinical isolates for which ampicillin-sulbactam MICs were between 16/8 and 32/16 micrograms/ml, a slight delay in killing was noted with three of the strains. This delay was followed by a rapid 2- to 3-log drop in the level of bacteremia, and both doses of ampicillin-sulbactam were 100% protective against lethal septicemia. With strain AFE, no killing was observed with the 40-mg/kg dose compared with a 2-log killing with the 80-mg/kg dose. This difference in killing correlated with a decreased protective efficacy of the 40-mg/kg dose. These data suggest that the 1.5-g preparation of ampicillin-sulbactam is as effective as the 3.0-g dose in the treatment of experimentally induced E. coli bacteremia, as long as ampicillin-sulbactam MICs are 32/16 micrograms/ml or less.

Complexity of Escherichia coli bacteremia pathophysiology evidenced by comparison of isolates from blood and portal of entry within single patients

2013 ◽  
Vol 303 (8) ◽  
pp. 529-532 ◽  
Author(s):  
Olivier Clermont ◽  
Jérémy Glodt ◽  
Charles Burdet ◽  
Dominique Pognard ◽  
Agnès Lefort ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Portal Of Entry

scholarly journals Enhancing mucosal immunity by transient microbiota depletion

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Simone Becattini ◽  
Eric R. Littmann ◽  
Ruth Seok ◽  
Luigi Amoretti ◽  
Emily Fontana ◽  
...  
Keyword(s):  
Intestinal Tract ◽  
Infectious Agents ◽  
Colonization Resistance ◽  
Mucosal Vaccination ◽  
Mucosal Surfaces ◽  
Pathogen Entry ◽  
Portal Of Entry ◽  
Optimal Protection ◽  
Antigenic Load ◽  
Chemotactic Gradient

Abstract Tissue resident memory CD8+ T cells (Trm) are poised for immediate reactivation at sites of pathogen entry and provide optimal protection of mucosal surfaces. The intestinal tract represents a portal of entry for many infectious agents; however, to date specific strategies to enhance Trm responses at this site are lacking. Here, we present TMDI (Transient Microbiota Depletion-boosted Immunization), an approach that leverages antibiotic treatment to temporarily restrain microbiota-mediated colonization resistance, and favor intestinal expansion to high densities of an orally-delivered Listeria monocytogenes strain carrying an antigen of choice. By augmenting the local chemotactic gradient as well as the antigenic load, this procedure generates a highly expanded pool of functional, antigen-specific intestinal Trm, ultimately enhancing protection against infectious re-challenge in mice. We propose that TMDI is a useful model to dissect the requirements for optimal Trm responses in the intestine, and also a potential platform to devise novel mucosal vaccination approaches.

Efficacy of Pneumococcal Vaccination against Recurrent Otitis Media

1980 ◽  
Vol 89 (3_suppl) ◽  
pp. 357-362 ◽  
Author(s):  
P. Karma ◽  
J. Luotonen ◽  
J. Pukander ◽  
M. Leinonen ◽  
M. Timonen ◽  
...  
Keyword(s):  
Otitis Media ◽  
Pneumococcal Vaccine ◽  
Capsular Polysaccharide ◽  
Protective Efficacy ◽  
Acute Otitis Media ◽  
Pneumococcal Vaccination ◽  
Haemophilus Influenzae Type ◽  
Vaccine Type ◽  
Parenteral Immunization

For this study, 781 children, aged 3 to 83 months, after presenting with acute otitis media, were immunized with either 14-valent pneumococcal or Haemophilus influenzae type b capsular polysaccharide vaccine. The vaccines were tolerated well. Antibody responses to the 14 pneumococcal polysaccharide types, measured by radioimmunoassay, were fair to good and increased with age, with the exception of types 1, 6 and 12 to which the responses were generally poor. During the follow-up of 1–17 months, average 13 months, 45 vaccine type (except type 6) pneumococcal recurrences were met among 456 pneumococcal-vaccinated and 45 among 288 H. influenzae-vaccinated children, at least six months old ( P < .05). The corresponding protective efficacy by the pneumococcal vaccine was 37%, for the first six months, 51% ( P < .01). No protection by the pneumococcal vaccine was seen against group 6 pneumococci, nor among 19 infants under six months of age. Nonvaccine type pneumococcal and H. influenzae recurrences did not significantly concentrate in either of the vaccination groups. Thus, it seems that parenteral immunization of children can reduce the recurrence rate of otitis media caused by pneumococci of types (except type 6) present in the vaccine.

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