Molecular Cloning, Expression and Purification of Truncated hpd Fragment of Haemophilus influenzae in Escherichia coli.

Background: Nontypeable Haemophilus influenzae (NTHi) is a significant pathogen in children, causing otitis media, sinusitis, conjunctivitis, pneumonia, and occasionally invasive infections. Protein D (PD) belongs to the minor outer-membrane proteins of H. influenza.

Prokaryotic High-Level Expression System in Producing Adhesin Recombinant Protein E of Nontypeable Haemophilus influenzae.

Background: Adhesion protein E (PE) of Haemophilus influenzae is a 16 - 18 kDa protein with 160 amino acids which causes adhesion to epithelial cells and acts as a major factor in pathogenesis.

Objectives: In this study, we performed cloning, expression and purification of PE as a candidate antigen for vaccine design upon further study.

Materials And Methods: At first, the pe gene of NTHi ATCC 49766 strain (483 bp) was amplified by PCR.

Co-expression of hepatitis C virus polytope-HBsAg and p19-silencing suppressor protein in tobacco leaves.

Context: Plants transformed by virus-based vectors have emerged as promising tools to rapidly express large amounts and inexpensive antigens in transient condition.

Objective: We studied the possibility of transient-expression of an HBsAg-fused polytopic construct (HCVpc) [containing H-2d and HLA-A2-restricted CD8+CTL-epitopic peptides of C (Core; aa 132-142), E6 (Envelope2; aa 614-622), N (NS3; aa 1406-1415), and E4 (Envelope2; aa 405-414) in tandem of CE6NE4] in tobacco (Nicotiana tabacum) leaves for the development of a plant-based HCV vaccine.

Materials And Methods: A codon-optimized gene encoding the Kozak sequence, hexahistidine (6×His)-tag peptide, and HCVpc in tandem was designed, chemically synthesized, fused to HBsAg gene, and inserted into Potato virus X (PVX-GW) vector under the control of duplicated PVX coat protein promoter (CPP).

Vaccination with recombinant L7/L12-truncated Omp31 protein induces protection against Brucella infection in BALB/c mice.

Brucellosis is the most common bacterial zoonotic disease worldwide and no vaccine is available for the prevention of human brucellosis. In humans, brucellosis is mostly caused by Brucella melitensis and Brucella abortus. The Outer membrane protein 31 (Omp31) and L7/L12 are immunodominant and protective antigens conserved in human Brucella pathogens.

Intranasal immunization with fusion protein MrpH·FimH and MPL adjuvant confers protection against urinary tract infections caused by uropathogenic Escherichia coli and Proteus mirabilis.

Urinary tract infections (UTIs) caused by Uropathogenic Escherichia coli (UPEC) and Proteus mirabilis are among the most common infections in the world. Currently there are no vaccines available to confer protection against UTI in humans. In this study, the immune responses and protection of FimH of UPEC with MrpH antigen of P.

Antigenicity and immunogenicity of fused B-subunit of heat labile toxin of Escherichia coli and colonization factor antigen I polyepitopes.

Linear B-cell epitopes ((93)AKEFEAAAL(101) and (66)PQLTDVLN(73)) of CfaB were genetically fused to ltb-(gly)5-cfaB(1-25). Sera of rabbits immunized with fusion proteins reacted strongly with solid-phase bound ETEC bacteria bearing CFA/I fimbriae. Sera failed to agglutinate or inhibit hemagglutination promoted by CFA/I-positive strain which may be due to solvent inaccessibility of epitope residues on intact fimbriae.

Enteroaggregative Escherichia coli, a heterogenous, underestimated and under-diagnosed E. coli pathotype in Iran.

The main features of enteroaggregative Escherichia coli (EAEC) pathogenesis include attachment of bacteria to the intestinal mucosa, production of various toxins and cytotoxins, and stimulation of mucosal inflammation. 'Virulence' genes encode these features. Comparison of different EAEC isolates has shown that the virulence gene content of these isolates varies considerably.

In silico and in vivo studies of truncated forms of flagellin (FliC) of enteroaggregative Escherichia coli fused to FimH from uropathogenic Escherichia coli as a vaccine candidate against urinary tract infections.

The new generation of vaccines against infectious diseases is based on recombinant fusion proteins. Flagellin (FliC) of enteroaggregative Escherichia coli (EAEC) could be considered as a potent adjuvant in designing new vaccines. However, because of its large size, incorporation of this protein with a vaccine antigen might negatively influence recognition of the vaccine epitopes by the immune system.

Genotypic and phenotypic comparison of enteroaggregative Escherichia coli isolates from HIV-positive and non-HIV diarrheal samples.

Enteroaggregative Escherichia coli (EAEC) have been isolated from both HIV-positive and non-HIV diarrheal samples. In this study a collection of 18 isolates from these two groups were compared for biofilm formation and antibiotic resistance and for the presence of 14 virulence-related genes. All the HIV-positive and over 66% of the non- HIV strains were PCR-negative for adhesion-related sequences indicating that as yet unknown adhesins may play a role.

Expression of Shigella flexneri ipaB Gene in Tobacco.

Background: Shigellosis is a leading cause of diarrhea in many developing countries and although the disease can be controlled and managed with antibiotics, the constant emergence of resistant species requiring ever newer antibacterial drugs make development of an effective vaccine necessary. The bacteria are highly contagious and since immunity to Shigella is serotype-specific a multi-serotype vaccine is required for adequate protection. Proteins encoded by Shigella invasion plasmid, which are part of the Type Three Secretion System (TTSS) of this bacteria, are good candidate as vaccine targets since they are both immunogenic and conserved between different Shigella species.

Comparison of multiplex PCR with serogrouping and PCR-RFLP of fliC gene for the detection of enteropathogenic Escherichia coli (EPEC).

Enteropathogenic Escherichia coli (EPEC) comprise one of the six categories of diarrhoeagenic E. coli (DEC). EPEC is subgrouped into typical (tEPEC) and atypical (aEPEC).

Comparison of virulence markers and antibiotic resistance in enterotoxigenic Escherichia coli isolated ten years apart in Tehran.

Introduction: Enterotoxigenic Escherichia coli (ETEC) causes diarrhoea by producing heat-labile (LT) or heat-stable (ST) enterotoxins after colonizing the small intestine by means of colonization factors (CFs). Although detection of the toxins is sufficient for verification of ETEC isolates, toxin-positive strains may be further analyzed for the presence of CFs. Antibiotics may shorten the duration of diarrhoea caused by ETEC, but the rapid emergence of resistant strains limits their usefulness.

Immune response against adhesins of enteroaggregative Escherichia coli immunized by three different vaccination strategies (DNA/DNA, Protein/Protein, and DNA/Protein) in mice.

Enteroaggregative Escherichia coli (EAEC) are an increasingly recognized enteric pathogen. It is a cause of both acute and persistent diarrhoea among children, adults and HIV-infected persons, in both developing and developed countries. The aggregative adherence of EAEC is due to the presence of aggregative adherence fimbriaes (AAFs).