The enterobacterial common antigen (ECA) is a polysaccharide composed of polysaccharide repeats that are located in the outer membrane of almost all Enterobacteriaceae bacteria and has diverse biological functions. ECA is synthesized by the synergistic action of multiple genes that are present in clusters on the genome of Enterobacteriaceae bacteria, forming the ECA antigen gene cluster, an important virulence factor that plays a role in host invasion and survival of Enterobacteriaceae in vivo. ECA also plays an important role in the maintenance of the bacterial outer membrane permeability barrier, flagella gene expression, swarming motility, and bile salts resistance. In addition, ECALPS, anchored in the core region of bacterial lipopolysaccharide, is an important surface antigen for bacteria, stimulating high levels of antibody production in the host and could be a target for vaccine research. This review summarizes ECA purification, genes involved in ECA biosynthesis, its immunological characteristics, biological functions and clinical applications.
Antigens, Bacterial/genetics* ; Enterobacteriaceae/genetics* ; Lipopolysaccharides ; Polysaccharides

Xanthomonas campestris pv. campestris (Xcc), the pathogenic agent of black rot disease in cruciferous plants, produces large amount of extracellular polysaccharide (EPS), which has found wide applications in industry. For the great commercial value of the xanthan gum, many of the genes involved in EPS biosynthesis have been cloned and the mechanism of EPS biosynthesis also has been studied. In order to clone genes involved in EPS biosynthesis, Xcc wild-type strain 8004 was mutagenized with transposon Tn5 gusA5, and a number of EPS-defective mutants were isolated in our previous work. The Tn5 gusA5 inserted sites of these mutants were located by using thermal asymmetric interlaced PCR, and results showed that two EPS-defective mutants were insertion mutants of the gene wxcA which involved in lipopolysaccharide (LPS) biosynthesis. The gene wxcA involved in lipopolysaccharide biosynthesis but dose not extracellular polysaccharide in others' report. wxcA::Tn5 gusA5 mutant 021C12, the polar mutant, was complemented with recombinant plasmid pLATC8570 harboring an intact wxcA gene in this work, but the yield of EPS of the wxcA::Tn5 gusA5 mutant was not restored. In order to identify the function of wxcA gene of Xcc 8004 strain, the gene wxcA was deleted by gene replacement strategy, and the no-polar mutant of wxcA was obtained. DeltawxcA mutant strain, named Xcc 8570, was confirmed by using both PCR and southern analysis. Beside the LPS biosynthesis of deltawxcA mutant was affected, The EPS yield of deltawxcA mutant strain reduced by 50% as compared with the wild-type strain 8004. DeltawxcA mutant could be complemented in trans with the intact wxcA gene, and the EPS yield of the mutant was restored. The combined data showed that wxcA gene not only involved in LPS biosynthesis but also EPS yield in Xcc 8004 strain.
Cell Proliferation ; Genes, Bacterial ; physiology ; Lipopolysaccharides ; biosynthesis ; Mutation ; Polysaccharides, Bacterial ; biosynthesis ; Xanthomonas campestris ; genetics

OBJECTIVETo observe the effects of lipopolysaccharides of Bacterium prodigiosum (BP-LPS) in inhibiting tumor growth and improving immunosuppression in mice.

METHODSIn mice bearing S180 tumor and a mouse model of immunosuppression induced by cyclophosphamide (CTX), the tumor growth, indexes of the immune organs and peripheral white blood cell count were measured after intraperitoneal injection of BP-LPS.

RESULTSInjections of BP-LPS (40 U/kg) for 8 consecutive days resulted in a significant inhibition of the tumor growth in mice bearing S180 tumor (P<0.01), with a dose-dependent increase of the spleen indexes but no obvious changes in the thymus indexes. Intraperitoneal injections of BP-LPS for 7 days inhibited the reduction of peripheral white blood cells and spleen indexes in immunosuppressive mice, but did not produce any significant changes in normal mice.

CONCLUSIONBP-LPS can inhibit the tumor growth in tumor-bearing mice and enhance the immune functions of immunosuppressive mice.

Animals ; Antineoplastic Agents ; pharmacology ; Female ; Immunosuppressive Agents ; pharmacology ; Lipopolysaccharides ; isolation & purification ; pharmacology ; Male ; Mice ; Polysaccharides, Bacterial ; isolation & purification ; pharmacology ; Random Allocation ; Serratia ; chemistry

OBJECTIVES: Toll-like receptors (TLRs) detect microbial infections and they can directly induce innate host defense responses. TLR 2 has been shown to be primarily involved in the recognition of peptidoglycans and lipoteichoic acid of gram positive bacteria. TLR 4 recognizes lipopolysaccharides and lipoteichoic acids from both gram-negative and gram-positive bacteria. Both mutations lead a reduced capacity to elicit inflammation and they increase the risk for gram-positive and negative infections. This study was performed to investigate the expressions of TLR 2 and 4 and their mutations in patients suffering with otitis media and middle ear effusion. METHODS: Middle ear fluid samples were collected from 40 otitis media effusion (OME) patients who had ventilating tubesinserted. Bacteria in the effusion fluid were detected by standard bacterial culture. The secreted IgG, IgA and IgM were measured by Enzyme-linked immunosorbent assay. TLR 2 and 4 were assessed by performing RT-PCR. The genomic DNA from each patient was isolated from the middle ear fluid samples that were collected from 60 OME patients, and the presence of mutations was determined by performing restriction digestion and DNA sequencing analysis. RESULTS: Among the 40 middle ear fluid samples, bacteria were detected in 13 middle ear fluid samples. The amounts of IgM, IgA, and IgG were 151.20+/-60.94 ng/mL, 21.59+/-7.96 ng/mL and 11.55+/-16.98 ng/mL, respectively. TLR 2 and 4 were expressed in the middle ear fluid and the expression of TLR 2 was higher than that of TLR 4. However, there was no correlation between the expressions of TLR 2 and 4, and the concentration of immunoglobulin or the presence of bacteria (P>0.05). There ware no mutations of TLR 2 (Arg753Gln, Arg677Trp) and TLR 4 (Asp299Gly, Thr399Ile). CONCLUSION: TLR 2 and 4 were expressed in all the middle ear fluid samples of OME, but the mutations of TLR 2 and 4 were not detected. TLR 2 and 4 may play a vital role in the immunological responses of patients with OME.
Bacteria ; Digestion ; DNA ; Ear, Middle ; Enzyme-Linked Immunosorbent Assay ; Gram-Positive Bacteria ; Humans ; Immunoglobulin A ; Immunoglobulin G ; Immunoglobulin M ; Immunoglobulins ; Inflammation ; Lipopolysaccharides ; Otitis ; Otitis Media ; Otitis Media with Effusion ; Peptidoglycan ; Sequence Analysis, DNA ; Stress, Psychological ; Teichoic Acids ; Toll-Like Receptors

The extracellular polysaccharides (EPS) of N. flagelliforme were purified by DEAE anion exchange chromatography and Sephadex G100 gel filtration chromatography. And two main components named NFPS1 and NFPS2 were obtained respectively. The physico-chemical characteristics of NFPS2 were analyzed and compared with NFPS0, which was obtained from field colony of N. flagelliforme. These results showed that both of NFPS2 and NFPSO were composed of four monosaccharides: glucose, xylose, galactose and mannose. The apparent molecular weight of NFPS2 and NFPS0 was estimated to be 2.79 x 10(5), 2.26 x 10(5) respectively. They are non-sulfated polysaccharides, free of protein and nuclear acid. The thermal analysis indicated that there was a decomposition peak at 245 degrees C in thermogravimetric (TG) curves. However, the microstructure analysis showed that they had different porous structures.
Extracellular Space ; chemistry ; Nostoc ; chemistry ; Polysaccharides ; chemistry ; isolation & purification ; Polysaccharides, Bacterial ; chemistry ; isolation & purification

OBJECTIVETo investigate the expression of Toll like receptor 2 (TLR2) and interleukin-1 beta (IL-1 beta) of cultured human periodontal ligament cells (HPDLCs) activated by Enterococcus faecalis (E. faecalis) lipoteichoic acid (LTA).

METHODSHPDLCs that were obtained from the periodontal tissues of healthy humans were maintained in proper condition. Flow cytometry was used to detect the expression of TLR2 on normal HPDLCs and infectious HPDLCs which were incubated with 0.1, 1, 10 microg mL(-1) E. faecalis LTA for 24 h. IL-1 beta was detected by enzyme linked immunosorbent assay (ELISA) after incubating with LTA of the above concentration for 12, 24 and 48 h or pretreated with TLR2 neutralizing antibody for 1 h and then co-cultured with 1 microg mL(-1) LTA for 24 h.

RESULTSE. faecalis LTA promoted the expression of TLR2 in normal HPDLCs. The difference had statistical significance (P<0.05). IL-1 beta secretion could be detected 12h after stimulation with LTA and increasingly escalate within 48h (P<0.05). TLR2 neutralizing antibody had no evident effect on IL-1 beta generation stimulating by E. faecalis LTA.

CONCLUSIONE. faecalis LTA can increase the expression of TLR2 and IL-1 beta in normal HPDLCs.

Cell Line ; Enterococcus faecalis ; Humans ; Interleukin-1beta ; Lipopolysaccharides ; Periodontal Ligament ; Teichoic Acids ; Toll-Like Receptor 2

OBJECTIVETo observe the production of interleukin (IL)-1beta, IL-6 and tumor necrosis factor alpha (TNFalpha) from stimulated human fibroblast with abstract from cell wall of Actinomyces naeslundii ATCC19246.

METHODSThe abstract from the cell wall from Actinomyces naeslundii were extracted and purified with the method of purifying lipoteichoic acid(LTA) and stimulated the THP-1 with three different concentrations (1, 10, 100 mg/mL). The level of IL-1beta, IL-6 and TNFalpha in the supernatant was quantitatively analyzed by ELISA. Results Abstracts at the concentrations of 10, 100 mg/mL significantly produced IL-1beta, IL-6 and TNFalpha, especially 10 mg/mL.

CONCLUSIONThe abstract from cell wall of Actinomyces naeslundii may significantly increase IL-1beta, IL-6 and TNFalpha level in the supernatant of THP-1, and the increasing level is different with the concentrations.

Actinomyces ; Fibroblasts ; Humans ; Interleukin-1 ; Interleukin-1beta ; Interleukin-6 ; Lipopolysaccharides ; Teichoic Acids ; Tumor Necrosis Factor-alpha

The paper dealt with the characterization of polysaccharide of Paecilomyces lilacinus NH-PL-03 strain. First, we extracted and purified exude polysaccharide from the fungal fermentation broth by ethanol depositing method. Second, the proteins were removed by the Sevage method from the crude polysaccharide. Third, the purified polysaccharide (EP-1) was obtained after Superdex G-75 column separation. The results of UV-spectrometer and Sephacryl S-200 HR chromatography experiments showed that the EP-1 was a homogeneous pure polysaccharide with molecular weight of 35.2 kDa. Tested by paper chromatography analysis using the complete hydrolysis by sulfuric acid, we found that the EP-1 comprise single component as glucose. The chemical structure of EP-1 was confirmed as a kind of linear glucan linked by beta-(1,3) linkage. The Congo red reaction performed that EP-1 probable presented a triple-helical conformation in the dilute alkali.
Molecular Structure ; Paecilomyces ; chemistry ; Polysaccharides, Bacterial ; chemistry ; isolation & purification

To investigate the effect of ginseng neutral polysaccharide on gut microbiota composition and diversity as well as the therapeutic effect for antibiotic associated diarrhea( AAD) in mice. The water-soluble ginseng neutral polysaccharide( WGPN) was purified from water-soluble ginseng polysaccharides( WGP) by DEAE-sepharose fast flow column,which was obtained from the roots of Panax ginseng. AAD mice were induced by gastric gavage with lincomycin hydrochloride,followed by administration of normal saline( natural recovery group,NR) or WGPN( WGPN group) for one week. Body weight changes,psychosis and diarrhea status were observed and assessed. 12 h after the last administration,histological observation of ileum and 16 S rRNA high throughput sequencing analysis of intestinal contents were conducted to identify the effects of WGPN on AAD mice. The results showed that WGPN could alleviate the symptoms of diarrhea in mice,decrease the inflammation and edema of ileum,and increase the length of intestinal villi. As compared to NR mice,WGPN could increase the relative abundance of Lactobacillus,and significantly decrease the relative abundance of Bacteroides,Streptococcus,Ochrobactrum and Pseudomonas at the genus level. In conclusion,WGPN could improve the gut microecology by recovering the ileum structure and improving the diversity and composition of the gut microbiota in AAD mice.
Animals ; Anti-Bacterial Agents ; Diarrhea ; Gastrointestinal Microbiome ; Mice ; Panax ; Polysaccharides

Bacterial surface glycans perform a diverse and important set of biological roles, and have been widely used in the treatment of bacterial infectious diseases. The majority of bacterial surface glycans are decorated with diverse rare functional groups, including amido, acetamidino, carboxamido and pyruvate groups. These functional groups are thought to be important constituents for the biological activities of glycans. Chemical synthesis of glycans bearing these functional groups or their variants is essential for the investigation of structure-activity relationships by a medicinal chemistry approach. To date, a broad choice of synthetic methods is available for targeting the different rare functional groups in bacterial surface glycans. This article reviews the structures of naturally occurring rare functional groups in bacterial surface glycans, and the chemical methods used for installation of these groups.
Bacterial Infections ; Humans ; Polysaccharides/chemistry* ; Structure-Activity Relationship