Development of a novel glycoengineering platform for the rapid production of conjugate vaccines

Conjugate vaccines produced either by chemical or biologically conjugation have been demonstrated to be safe and efficacious in protection against several deadly bacterial diseases. However, conjugate vaccine assembly and production have several shortcomings which hinders their wider availability. Here, we developed a tool, Mobile-element Assisted Glycoconjugation by Insertion on Chromosome, MAGIC, a novel biotechnological platform that overcomes the limitations of the current conjugate vaccine design method(s). As a model, we focused our design on a leading bioconjugation method using N-oligosaccharyltransferase (OTase), PglB. The installation of MAGIC led to at least twofold increase in glycoconjugate yield via MAGIC when compared to conventional N-OTase based bioconjugation method(s). Then, we improved MAGIC to (a) allow rapid installation of glycoengineering component(s), (b) omit the usage of antibiotics, (c) reduce the dependence on protein induction agents. Furthermore, we show the modularity of the MAGIC platform in performing glycoengineering in bacterial species that are less genetically tractable than the commonly used Escherichia coli. The MAGIC system promises a rapid, robust and versatile method to develop vaccines against serious bacterial pathogens. We anticipate the utility of the MAGIC platform could enhance vaccines production due to its compatibility with virtually any bioconjugation method, thus expanding vaccine biopreparedness toolbox.

Lactobacillus fermentum 3872 as a potential tool for combatting Campylobacter jejuni infections

Due to the global spread of multidrug resistant pathogenic bacteria, alternative approaches in combating infectious diseases are required. One such approach is the use of probiotics. Lactobacillus fermentum 3872 is a promising probiotic bacterium producing a range of antimicrobial compounds, such as hydrogen peroxide and lactic acid. In addition, previous studies involving genome sequencing and analysis of L. fermentum 3872 allowed the identification of a gene encoding a cell surface protein referred to as collagen binding protein (CBP) (not found in other strains of the species, according to the GenBank database), consisting of a C-terminal cell wall anchor domain (LPXT), multiple repeats of ‘B domains' that form stalks presenting an “A domain” required for adhesion. In this study, we found that the CBP of L. fermentum 3872 binds to collagen I present on the surface of the epithelial cells lining the gastrointestinal tract. Moreover, we found that this host receptor is also used for attachment by the major gastrointestinal pathogen, Campylobacter jejuni. Furthermore, we identified an adhesin involved in such interaction and demonstrated that both L. fermentum 3872 and its CBP can inhibit binding of this pathogen to collagen I. Combined with the observation that C. jejuni growth is affected in the acidic environment produced by L. fermentum 3872, the finding provides a good basis for further investigation of this strain as a potential tool for fighting Campylobacter infections.

Potential probiotic-associated traits revealed from completed high quality genome sequence of Lactobacillus fermentum 3872

The article provides an overview of the genomic features of Lactobacillus fermentum strain 3872. The genomic sequence reported here is one of three L. fermentum genome sequences completed to date. Comparative genomic analysis allowed the identification of genes that may be contributing to enhanced probiotic properties of this strain. In particular, the genes encoding putative mucus binding proteins, collagen-binding proteins, class III bacteriocin, as well as exopolysaccharide and prophage-related genes were identified. Genes related to bacterial aggregation and survival under harsh conditions in the gastrointestinal tract, along with the genes required for vitamin production were also found.

Lactobacillus fermentum 3872 genome sequencing reveals plasmid and chromosomal genes potentially involved in a probiotic activity

In this report we describe a Lactobacillus fermentum 3872 plasmid (pLF3872) not previously found in any other strain of this species. The analysis of the complete sequence of this plasmid revealed the presence of a gene encoding a large collagen-binding protein (CBP), as well as the genes responsible for plasmid maintenance and conjugation. Potential roles of CBP and a chromosomally encoded fibronectin-binding protein (FbpA) in probiotic activity are discussed.

Specific genetic features of Campylobacter jejuni strain G1 revealed by genome sequencing

This report describes a draft genome sequence of Campylobacter jejuni strain G1. The strain contains no plasmids, despite being resistant to tetracycline (Tet). Comparison of the genome of this strain with that of a reference strain NCTC 11168 (Tet sensitive) revealed the presence of a candidate gene that may be responsible for antibiotic resistance, as well as the genes involved in the synthesis of ganglioside-mimicking molecules responsible for the development of a neurodegenerative disorder, Guillain-Barré syndrome.