Development and Validation of Shiga Toxin-Producing Immunodiagnostic Assay.

Shiga toxin (Stx)-producing (STEC) and its subgroup enterohemorrhagic are important pathogens involved in diarrhea, which may be complicated by hemorrhagic colitis and hemolytic uremic syndrome, the leading cause of acute renal failure in children. Early diagnosis is essential for clinical management, as an antibiotic treatment in STEC infections is not recommended. Previously obtained antibodies against Stx and Stx toxins were employed to evaluate the sensitivity and specificity of the latex Agglutination test (LAT), lateral flow assay (LFA), and capture ELISA (cEIA) for STEC detection.

Antibodies to Shiga toxins in Brazilian cattle.

Cattle are considered a reservoir of Shiga toxin-producing Escherichia coli (STEC). There is no information about the presence of antibodies against Shiga toxins in Brazilian bovine serum. Using ELISA, all sera tested showed antibodies against the two main STEC virulence factors; Stx1 and Stx2.

Potential for colonization of O111:H25 atypical enteropathogenic E. coli.

Using clonal phylogenetic methods, it has been demonstrated that O111:H25 atypical enteropathogenic E. coli (aEPEC) strains belong to distinct clones, suggesting the possibility that their ability to interact with different hosts and abiotic surfaces can vary from one clone to another. Accordingly, the ability of O111:H25 aEPEC strains derived from human, cat and dogs to adhere to epithelial cells has been investigated, along with their ability to interact with macrophages and to form biofilms on polystyrene, a polymer used to make biomedical devices.

Single Chain Variable Fragments Produced in Escherichia coli against Heat-Labile and Heat-Stable Toxins from Enterotoxigenic E. coli.

Background: Diarrhea is a prevalent pathological condition frequently associated to the colonization of the small intestine by enterotoxigenic Escherichia coli (ETEC) strains, known to be endemic in developing countries. These strains can produce two enterotoxins associated with the manifestation of clinical symptoms that can be used to detect these pathogens. Although several detection tests have been developed, minimally equipped laboratories are still in need of simple and cost-effective methods.

Development of a rapid agglutination latex test for diagnosis of enteropathogenic and enterohemorrhagic Escherichia coli infection in developing world: defining the biomarker, antibody and method.

Background: Enteropathogenic and enterohemorrhagic Escherichia coli (EPEC/EHEC) are human intestinal pathogens responsible for diarrhea in both developing and industrialized countries. In research laboratories, EPEC and EHEC are defined on the basis of their pathogenic features; nevertheless, their identification in routine laboratories is expensive and laborious. Therefore, the aim of the present work was to develop a rapid and simple assay for EPEC/EHEC detection.

Different assay conditions for detecting the production and release of heat-labile and heat-stable toxins in enterotoxigenic Escherichia coli isolates.

Enterotoxigenic Escherichia coli (ETEC) produce heat-labile (LT) and/or heat-stable enterotoxins (ST). Despite that, the mechanism of action of both toxins are well known, there is great controversy in the literature concerning the in vitro production and release of LT and, for ST, no major concerns have been discussed. Furthermore, the majority of published papers describe the use of only one or a few ETEC isolates to define the production and release of these toxins, which hinders the detection of ETEC by phenotypic approaches.

An improved whole cell pertussis vaccine with reduced content of endotoxin.

An improved whole cell pertussis vaccine, designated as Plow, which is low in endotoxicity due to a chemical extraction of lipo-oligosaccharide (LOS) from the outer membrane, was evaluated for safety, immunogenicity and potency, comparatively to a traditional whole cell pertussis vaccine. Current whole cell pertussis vaccines are effective but contain large quantities of endotoxin and consequently display local and systemic adverse reactions after administration. Endotoxin is highly inflammatory and contributes considerably to the reactogenicity as well as the potency of these vaccines.

Interaction between Shiga toxin and monoclonal antibodies: binding characteristics and in vitro neutralizing abilities.

Monoclonal antibodies (MAbs) have been employed either for diagnosis or treatment of infections caused by different pathogens. Specifically for Shiga toxin-producing Escherichia coli (STEC), numerous immunoassays have been developed for STEC diagnosis, showing variability in sensitivity and specificity when evaluated by reference laboratories, and no therapy or vaccines are currently approved. Thus, the aim of this work was the characterization of the interaction between MAbs against Stx1 and Stx2 toxins and their neutralizing abilities to enable their use as tools for diagnosis and therapy.

Rabies virus glycoprotein expression in Drosophila S2 cells. I. Functional recombinant protein in stable co-transfected cell line.

Recombinant rabies virus glycoprotein (rRVGP) was expressed in Drosophila melanogaster Schneider 2 (S2) cells. The cDNA encoding the entire RVGP gene was cloned in an expression plasmid under the control of the constitutive actin promoter (Ac), which was co-transfected into S2 cells together with a hygromycin selection plasmid. Selected S2 cell populations (S2AcRVGP) had a decreased ability to grow and consume substrates, when compared to the non-transfected cells (S2).

Antibodies produced against a fragment of filamentous haemagglutinin (FHA) of Bordetella pertussis are able to inhibit hemagglutination induced by the whole adhesin.

Filamentous hemagglutinin adhesin (FHA) is important for the adherence of Bordetella pertussis to the host ciliary epithelial cells of the respiratory tract. Several binding domains have been characterized in the FHA molecule. For example, an putative heparin-binding domain of FHA was previously located in the FHA(442-863) region.