The Complete Structure of the Core Oligosaccharide from Edwardsiella tarda EIB 202 Lipopolysaccharide

Structural Diversity among Edwardsiellaceae Core Oligosaccharides

The Edwardsiella genus presents five different pathogenic species: Edwardsiella tarda, E. anguillarum, E. piscicida, E. hoshinae and E. ictaluri. These species cause infections mainly in fish, but they can also infect reptiles, birds or humans. Lipopolysaccharide (endotoxin) plays an important role in the pathogenesis of these bacteria. For the first time, the chemical structure and genomics of the lipopolysaccharide (LPS) core oligosaccharides of E. piscicida, E. anguillarum, E. hoshinae and E. ictaluri were studied. The complete gene assignments for all core biosynthesis gene functions were acquired. The structure of core oligosaccharides was investigated by ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy. The structures of E. piscicida and E. anguillarum core oligosaccharides show the presence of →3,4)-L-glycero-α-D-manno-Hepp, two terminal β-D-Glcp, →2,3,7)-L-glycero-α-D-manno-Hepp, →7)-L-glycero-α-D-manno-Hepp, terminal α-D-GlcpN, two →4)-α-D-GalpA, → 3)-α-D-GlcpNAc, terminal β-D-Galp and →5-substituted Kdo. E. hoshinare core oligosaccharide shows only one terminal β-D-Glcp, and instead of terminal β-D-Galp a terminal α-D-GlcpNAc. E. ictaluri core oligosaccharide shows only one terminal β-D-Glcp, one →4)-α-D-GalpA and do not have terminal α-D-GlcpN (see complementary figure).

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2017-2018

This review is the tenth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization mass spectrometry (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2018. Also included are papers that describe methods appropriate to glycan and glycoprotein analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, new methods, matrices, derivatization, MALDI imaging, fragmentation and the use of arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Most of the applications are presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. The reported work shows increasing use of combined new techniques such as ion mobility and highlights the impact that MALDI imaging is having across a range of diciplines. MALDI is still an ideal technique for carbohydrate analysis and advancements in the technique and the range of applications continue steady progress.

Modulation of adipose tissue metabolism by microbial-derived metabolites

Obesity and its complications, including type 2 diabetes, cardiovascular disease, and certain cancers, have posed a significant burden on health and healthcare systems over the years due to their high prevalence and incidence. Gut microbial derivatives are necessary for the regulation of energy metabolism and host immunity, as well as for maintaining homeostasis of the intestinal environment. Gut flora metabolites may be a link between gut microbes and diseases, such as obesity, and help understand why alterations in the microbiota can influence the pathophysiology of human disease. This is supported by emerging evidence that microbial-derived metabolites, such as short-chain fatty acids, bile acids, tryptophan, trimethylamine-N-oxide, and lipopolysaccharides, can be beneficial or detrimental to the host by affecting organs outside the gut, including adipose tissue. Adipose tissue is the largest lipid storage organ in the body and an essential endocrine organ that plays an indispensable role in the regulation of lipid storage, metabolism, and energy balance. Adipose tissue metabolism includes adipocyte metabolism (lipogenesis and lipolysis), thermogenesis, and adipose tissue metabolic maladaptation. Adipose tissue dysfunction causes the development of metabolic diseases, such as obesity. Here, we review the current understanding of how these microbial metabolites are produced and discuss both established mechanisms and the most recent effects of microbial products on host adipose tissue metabolism. We aimed to identify novel therapeutic targets or strategies for the prevention and treatment of obesity and its complications.

Antimicrobial Activity Assay of Liposomal Lipopolysaccharide Extracted from Escherichia coli

Escherichia coli (E. coli) is a bacterial bacillus known to be negative for the gram dye, and it is part of the normal flora inside the human body. The current study aimed to investigate the possibility of using lipopolysaccharides (LPS) as an antimicrobial agent. A total of 30 isolates of E. coli were collected from 100 specimens of urine isolated from patients with recurrent urinary tract infections (UTIs) referring to Al-Sadr Teaching Hospital. The samples were cultured on identification media; thereafter, they were diagnosed according to the phenotypic form, biochemical tests, and finally by VITK-2. The results of the prevalence of E. coli isolates illustrated that from 30 isolates of E. coli which were collected from 100 urine specimens, 14 (46.6%), 6 (20%), and 10 (33.3%) cases belonged to the urinary tract infections, kidney stones, and urinary catheter samples, respectively. The isolates displayed multiple drug resistance (MDR) to most of the antibiotics used in the study. Therefore, the lipopolysaccharide extracted from E. coli was used as an antimicrobial agent. The recorded data obtained from the polymerase chain reaction (PCR) for WaaA, WaaC, wamB, and wabG genes demonstrated that the isolates possessed biosynthesis genes for LPS. The results indicated that LPS at concentrations of 150, 250, and 500 μg/ml has as an anti-growth agent for Klebsiella pneumonia, Proteus mirabilis, Salmonella typhi, Pseudomonas aeruginosa, Bacillus subtilis, Staph aureus, and candida albicans. The highest inhibitory effect was observed on K. pneumonia, P. mirabilis, S. typhi, B. subtilis, and C. albicans, as compared to the control antimicrobials agents (Amoxicillin, Nystatin). The LPS loaded on liposome nanoparticles can open new horizons in medicine by its inclusion in the manufacture of broad-spectrum antibiotics.

Structural analysis of Edwardsiella tarda PCM 1155 O-polysaccharide revealed the presence of unique β-L-RhapNAc3NAc derivative

The chemical structure of the lipopolysaccharide O-polysaccharide repeating unit of Edwardsiella tarda strain PCM 1155 was studied for the first time. The complete structure of repeating unit was investigated by chemical methods, 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, and matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The rarely occurring monosaccharide, 2,3-diacetamido-2,3,6-trideoxy-l-mannose (L-RhapNAc3NAc) was identified. The following structure was established.