Antigen delivery format variation and formulation stability through use of a hybrid vector.

A hybrid biological-biomaterial antigen delivery vector comprised of a polymeric shell encapsulating an core was previously developed for antigen production and subsequent delivery. Due to the engineering capacity of the bacterial core, the hybrid vector provides unique opportunities for immunogenicity optimization through varying cellular localization (cytoplasm, periplasm, cellular surface) and type (protein or DNA) of antigen. In this work, three protein-based hybrid vector formats were compared in which the pneumococcal surface protein A (PspA) was localized to the cytoplasm, surface, and periplasmic space of the bacterial core for vaccination against pneumococcal disease.

Determination of genetic diversity of species using mini-circle kDNA, in Iran-Iraq countries border.

Background And Objective: Cutaneous leishmaniasis (CL) is one of the most important diseases worldwide, with a different range of prevalence in endemic areas. Anthroponotic and zoonotic CL are two epidemiological forms of CL, in Iran. Although Ilam Province in the west of Iran is one of the main endemic areas of the disease, there is no inclusive study to determine the genetic variations of parasite in these areas.

Atolypenes, Tricyclic Bacterial Sesterterpenes Discovered Using a Multiplexed In Vitro Cas9-TAR Gene Cluster Refactoring Approach.

Most natural product biosynthetic gene clusters identified in bacterial genomic and metagenomic sequencing efforts are silent under laboratory growth conditions. Here, we describe a scalable biosynthetic gene cluster activation method wherein the gene clusters are disassembled at interoperonic regions in vitro using CRISPR/Cas9 and then reassembled with PCR-amplified, short DNAs, carrying synthetic promoters, using transformation assisted recombination (TAR) in yeast. This simple, cost-effective, and scalable method allows for the simultaneous generation of combinatorial libraries of refactored gene clusters, eliminating the need to understand the transcriptional hierarchy of the silent genes.

Increased production of yersiniabactin and an anthranilate analog through media optimization.

Yersiniabactin (Ybt) is a mixed nonribosomal peptide-polyketide natural product that binds a wide range of metals with the potential to impact processes requiring metal retrieval and removal. In this work, we substantially improved upon the heterologous production of Ybt and an associated anthranilate analog through systematic screening and optimization of culture medium components. Specifically, a Plackett-Burman design-of-experiments methodology was used to screen 22 components and to determine those contributing most to siderophore production.

Improved heterologous production of the nonribosomal peptide-polyketide siderophore yersiniabactin through metabolic engineering and induction optimization.

Biosynthesis of complex natural products like polyketides and nonribosomal peptides using Escherichia coli as a heterologous host provides an opportunity to access these molecules. The value in doing so stems from the fact that many compounds hold some therapeutic or other beneficial property and their original production hosts are intractable for a variety of reasons. In this work, metabolic engineering and induction variable optimization were used to increase production of the polyketide-nonribosomal peptide compound yersiniabactin, a siderophore that has been utilized to selectively remove metals from various solid and aqueous samples.

E. coli metabolic engineering for gram scale production of a plant-based anti-inflammatory agent.

In this report, the heterologous production of salicylate (SA) is the basis for metabolic extension to salicylate 2-O-β-d-glucoside (SAG), a natural product implicated in plant-based defense mechanisms. Production was optimized through a combination of metabolic engineering, gene expression variation, and co-culture design. When combined, SA and SAG production titers reached ~0.

In situ pneumococcal vaccine production and delivery through a hybrid biological-biomaterial vector.

The type and potency of an immune response provoked during vaccination will determine ultimate success in disease prevention. The basis for this response will be the design and implementation of antigen presentation to the immune system. Whereas direct antigen administration will elicit some form of immunological response, a more sophisticated approach would couple the antigen of interest to a vector capable of broad delivery formats and designed for heightened response.

Recent progress in therapeutic natural product biosynthesis using Escherichia coli.

E. coli has become a common host for the heterologous biosynthesis of natural products that demonstrate therapeutic value but suffer from access challenges posed by native production hosts. This review will highlight recent examples of heterologous products produced using E.

Molecular variation of the nonribosomal peptide-polyketide siderophore yersiniabactin through biosynthetic and metabolic engineering.

The production of the mixed nonribosomal peptide-polyketide natural product yersiniabactin (Ybt) has been established using E. coli as a heterologous host. In this study, precursor-directed biosynthesis was used to generate five new analogs of Ybt, demonstrating the flexibility of the heterologous system and the biosynthetic process in allowing compound diversity.

Total Biosynthesis and Diverse Applications of the Nonribosomal Peptide-Polyketide Siderophore Yersiniabactin.

Yersiniabactin (Ybt) is a mixed nonribosomal peptide-polyketide natural product natively produced by the pathogen Yersinia pestis. The compound enables iron scavenging capabilities upon host infection and is biosynthesized by a nonribosomal peptide synthetase featuring a polyketide synthase module. This pathway has been engineered for expression and biosynthesis using Escherichia coli as a heterologous host.

Molecular and parasitological study of cryptosporidium isolates from cattle in ilam, west of iran.

Background: Cryptosporidiosis is one of the most important parasitic infections in human and animals. This study was designed for survey on the prevalence of Cryptosporidium infection in farms of Ilam, west of Iran, using parasitology method and genotyping by Nested PCR-RFLP.

Methods: Fecal samples of 217 cattle were collected fresh and directly from the rectum of cattle.

Comparison of three malignancy risk indices and CA-125 in the preoperative evaluation of patients with pelvic masses.

Background: Patients with pelvic mass are the most referred patients to gynecologist. The aim of this study was to evaluate the ability of three malignancy risk indices (RMI 1, RMI 2 and RMI 3) and CA-125 to discriminate a benign from a malignant pelvic mass in our region (North of Iran).

Methods: This retrospective study was performed on 182 women with pelvic masses referred to Yahyanejad Hospital from 2007 to 2009.