| 1. |
- Aabenhus, Rune, et al.
(författare)
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Lectin Typing of Campylobacter concisus
- 2002
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Ingår i: Journal of Clinical Microbiology. - 1098-660X. ; 40:2, s. 715-717
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Tidskriftsartikel (refereegranskat)abstract
- A total of 44 clinical isolates and the type strain of the putative pathogen Campylobacter concisus were grouped based on their reactions with plant lectins. The optimized lectin typing system used C. concisus strains proteolytically pretreated and subsequently typed by using a panel of four lectins. The system grouped all 45 strains into 13 lectin reaction patterns, leaving no strain untypeable due to autoagglutination. Lectin types were both stable and reproducible.
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| 2. |
- Annuk, Heidi, et al.
(författare)
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Characterisation and differentiation of lactobacilli by lectin typing
- 2001
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Ingår i: Journal of Medical Microbiology. - 0022-2615. ; 50:12, s. 1069-1074
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Tidskriftsartikel (refereegranskat)abstract
- Lactobacillus isolates from healthy Estonian and Swedish children were characterised by a lectin typing technique; 56 isolates from six species (L. acidophilus, L. paracasei, L. plantarum, L. fermentum, L. brevis and L. buchneri) were tested. The typing system was based on an agglutination assay with a panel of six commercially available lectins, which,were chosen on the basis of their carbohydrate specificities. The isolates were also subjected to proteolytic degradation before lectin typing to decrease auto-agglutination of whole cells in the assay. The 56 isolates were divided into 15 different lectin types by their lectin agglutination patterns. Proteolytic treatment reduced auto-agglutination for the majority of species, apart from L. acidophilus, which remained predominantly auto-agglutinating (eight of nine strains). The system produced stable and reproducible results under standardised culture conditions. Lactobacilli are important bacteria for use as probiotics and this system may supplement current molecular typing techniques and may help in identification of strains that could be useful in this role.
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| 3. |
- Hynes, Sean, et al.
(författare)
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Comparative chemical and biological characterization of the lipopolysaccharides of gastric and enterohepatic helicobacters
- 2004
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Ingår i: Helicobacter. - : Wiley. - 1083-4389 .- 1523-5378. ; 9:4, s. 313-323
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Tidskriftsartikel (refereegranskat)abstract
- Background. The lipopolysaccharide of Helicobacter pylori plays an important role in colonization and pathogenicity. The present study sought to compare structural and biological features of lipopolysaccharides from gastric and enterohepatic Helicobacter spp. not previously characterized.Materials and methods. Purified lipopolysaccharides from four gastric Helicobacter spp. (H. pylori, Helicobacter felis, Helicobacter bizzozeronii and Helicobacter mustelae) and four enterohepatic Helicobacter spp. (Helicobacter hepaticus, Helicobacter bilis, Helicobacter sp. flexispira and Helicobacter pullorum) were structurally characterized using electrophoretic, serological and chemical methods.Results. Structural insights into all three moieties of the lipopolysaccharides, i.e. lipid A, core and O-polysaccharide chains, were gained. All species expressed lipopolysaccharides bearing an O-polysaccharide chain, but H. mustelae and H. hepaticus produced truncated semirough lipopolysaccharides. However, in contrast to lipopolysaccharides of H. pylori and H. mustelae, no blood group mimicry was detected in the other Helicobacter spp. examined. Intra-species, but not interspecies, fatty acid profiles of lipopolysaccharides were identical within the genus. Although shared lipopolysaccharide-core epitopes with H. pylori occurred, differing structural characteristics were noted in this lipopolysaccharide region of some Helicobacter spp. The lipopolysaccharides of the gastric helicobacters, H. bizzozeronii and H. mustelae, had relative Limulus amoebocyte lysate activities which clustered around that of H. pylori lipopolysaccharide, whereas H. bilis, Helicobacter sp. flexispira and H. hepaticus formed a cluster with approximately 100010,000-fold lower activities. H. pullorum lipopolysaccharide had the highest relative Limulus amoebocyte lysate activity of all the helicobacter lipopolysaccharides (10-fold higher than that of H. pylori lipopolysaccharide), and all the lipopolysaccharides of enterohepatic Helicobacter spp. were capable of inducing nuclear factor-Kappa B(NF-B) activation.Conclusions. The collective results demonstrate the structural heterogeneity and pathogenic potential of lipopolysaccharides of the Helicobacter genus as a group and these differences in lipopolysaccharides may be indicative of adaptation of the bacteria to different ecological niches.
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| 4. |
- Hynes, Sean, et al.
(författare)
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Glycoconjugate Binding of Gastric and Enterohepatic Helicobacter spp.
- 2003
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Ingår i: Infection and Immunity. - 1098-5522. ; 71:5, s. 2976-2980
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori is able to utilize several lectin-like, protein-carbohydrate interactions for binding to mucins, cell surfaces, and extracellular matrix proteins. As determined by hemagglutination assays and binding of radiolabeled bacteria to glycosphingolipids on thin-layer chromatograms, strains of gastric helicobacters and enterohepatic helicobacters, including Helicobacter canis, Helicobacter hepaticus, and Helicobacter bilis, also demonstrated evidence for the presence of lectin-hemagglutinin adhesins. In addition, in H. hepaticus and H. bilis, binding may be sialic acid dependent. The presence or absence and differences in the levels of activity of lectin adhesins may reflect the species' ecological niche.
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| 5. |
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| 7. |
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| 8. |
- Hynes, Sean, et al.
(författare)
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Toxins of the helicobacter genus and their roles in pathogenesis
- 2004
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Ingår i: Toxin Reviews. - 1556-9543. ; 23:1, s. 1-35
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Forskningsöversikt (refereegranskat)abstract
- In the 20 years since the discovery of Helicobacter pylori the number of formally described Helicobacter spp. has increased dramatically. The majority of species in the genus have been associated with some form of pathology. Similar to other Gram-negative bacteria, all helicobacters have lipopolysaccharides or endotoxins in the outer leaflet of their outer membrane which is an important modulator of the immune system. H. pylori endotoxin has a number of roles in the pathogenesis of the bacterium. Its relatively low biological and immunological activity and molecular mimicry may contribute to the chronic nature of infection through avoidance of host defence mechanisms and adhesion. In addition to endotoxins, various helicobacters also secrete distinct exotoxins capable of host cell damage. H. pylori has been shown to possess a cytotoxin capable of inducing vacuoles in epithelial cells termed vacuolating cytotoxin or VacA. Although VacA has a number of roles in the pathogenesis of H. pylori its use as a predictor of clinical outcome has yet to be established. In addition, similar to the closely related Campylobacter jejuni, a number of enterohepatic helicobacters express a cytolethal distending toxin capable of inducing severe cell damage in vivo and in vitro. Both endotoxins and exotoxins may play a combined role in the pathogenesis of Helicobacter spp. Both toxin types have been identified as being present on outer membrane vesicles shed by H. pylori which may act as antigen delivery vehicles and contribute to pathogenesis.
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| 9. |
- Kruszewska, Danuta, et al.
(författare)
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Effect of the antibacterial activity of pig pancreatic juice on human multiresistant bacteria.
- 2004
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Ingår i: Pancreas. - 0885-3177. ; 28:2, s. 191-199
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The role of the exocrine pancreas in regulating gut microflora colonization is unclear. The main objective in the current study was to assess the effect of pancreatic fluid on the growth of pathogenic bacteria and fungi. Methods: The antibacterial activity of pure pig pancreatic juice collected from catheterized, healthy, conscious, and anesthetized pigs was investigated with multiresistant microbial isolates and nonpathogenic strains. Studies were performed on pathogenic bacterial and fungi as well as lactic acid bacteria and reference strains. Results: Pancreatic juice was effective (P < 0.01) against multidrug resistant bacterial pathogens, whereas lactic acid bacteria were insensitive. The antibacterial action was independent of pancreatic juice proteolytic activity. The in vitro antibacterial properties of pancreatic juice last for several hours. Data suggest that broth composition may modulate the intensity of pancreatic juice antibacterial activity. Conclusions: Pancreatic juice antibacterial activity may be an important factor in limiting the colonization of pathogenic bacteria in the gastrointestinal tract. We postulate that observed antibacterial activity of the pancreatic juice could play an important role as one of the factors of innate immunity.
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