Teichoic acids of three type strains of the Bacillus subtilis group, Bacillus mojavensis VKM B-2650, Bacillus amyloliquefaciens subsp. amyloliquefaciens VKM B-2582, and Bacillus sonorensis VKM B-2652

Cell walls of three type strains of the Bacillus subtilis group, Bacillus mojavensis VKM B-2650, Bacillus amyloliquefaciens subsp. amyloliquefaciens VKM B-2582, and Bacillus sonorensis VKM B-2652, are characterized by the individual set of teichoic acids. All strains contained 1,3-poly(glycerol phosphates), unsubstituted, acylated with D-alanine, and glycosylated. The latter differ in the nature of the monosaccharide residue. Teichoic acids of B. mojavensis VKM B-2650^T and B. amyloliquefaciens subsp. amyloliquefaciens VKM B-2582^T contained α-glucopyranose, while those of B. sonorensis VKM B-2652^T contained β-glucopyranose and N-acetyl-α-D-glucosamine. Moreover, cell walls of B. mojavensis VKM B-2650^T contained a teichoic acid of poly(glycosylglycerol phosphate) nature with the following structure of the repeating unit: -4)-α-D-α-D-GlcpNAc-(1 → 3)]-Glcp-(1 → 2)-sn-Gro-(3-P-. The type strains have been characterized according to the composition of cell wall sugars and polyols. Application of teichoic acids (set and structure) as chemotaxonomic characteristics is discussed for six type strains of the Bacillus subtilis group. Polymer structures were determined by chemical and NMR spectroscopic techniques.     

Disaccharide 1-phosphate polymers of some representatives of the Bacillus subtilis group

Disaccharide 1-phosphate polymers as well as teichoic acids of various structures have been found in the cell walls of the representatives of the Bacillus subtilis group, namely Bacillus subtilis subsp. spizizenii VKM B-720 and VKM B-916, B. subtilis VKM B-517, and Bacillus vallismortis VKM B-2653^T. Disaccharide 1-phosphate polymers are composed of repeating units of the following structure: -P-4)-β-D-GlcpNAc-(1→6)-α-D-Galp-(1-, the N-acetylglucosamine residues are partially acetylated at positions O3 and O6 (VKM B-720 and VKM B-916); -P-4)-β-D-Glcp-(1→6)-α-D-GlcpNAc-(1-, the glucopyranose residues are partially acetylated at positions O2 or O3 (VKM B-517); -P-6)-α-D-GlcpNH ₃ ⁺ /α-D-GlcpNAc-(1→2)-α-D-Glcp-(1-, the N-acetylglucosamine residues are partially deacetylated (VKM B-2653^T). The structures of the two last disaccharide 1-phosphate polymers have not been reported so far for Gram-positive bacteria. The teichoic acids in the studied strains are O-D-alanyl-1,5-poly(ribitol phosphates) substituted with β-D-glucopyranose (VKM B-517, VKM B-720, VKM B-916) or 2-acetamido-2-deoxy-β-D-glucopyranose (VKM B-2653^T). The structures of the phosphate-containing polymers have been studied by chemical methods and by NMR spectroscopy.     

Risk factors of peripheral arterial disease: a case control study in Sri Lanka

Background

Peripheral artery disease (PAD) is an important global health problem and contributes to notable proportion of morbidity and mortality. This particular manifestation of systemic atherosclerosis is largely under diagnosed and undertreated. For sustainable preventive strategies in a country, it is mandatory to identify country-specific risk factors. We intended to assess the risk factors of PAD among adults aged 40–74 years.

Methods

This case control study was conducted in 2012–2013 in Sri Lanka. Seventy-nine cases and 158 controls in the age group of 40–74 years were selected for the study in order to have case to control ratio 1:2. The criterion for selecting cases and control was based on Ankle brachial pressure index (ABPI). Cases were selected from those who had ABPI 0.85 or less (ABPI ≤0.85) in either lower limb. Controls were selected from those ABPI score between 1.18 and 1.28 in both lower limbs. Only newly identified individuals with PAD were selected as cases. Controls were selected from the same geographical location and within the 5 year age group as cases.

Results

The history of diabetes mellitus more than 10 years (OR 5.8, 95% CI 2.2–14.2), history of dyslipidemia for more than 10 years (OR 4.9, 95% CI 2.1–16.2), history of hypertension for more than 10 years (OR 3.8, 95% CI 1.8–12.7) and smoking (OR 2.9, 95% CI 1.2–6.9), elevated HsCRP (OR 3.7, 95% CI 1.2–12.0) and hyperhomocysteinemia (OR 3.0, 95% CI 1.1–8.1) were revealed as country specific significant risk factor of PAD.

Conclusions

Diabetes mellitus, hypertension, dyslipidemia, smoking as well as elevated homocysteine and HsCRP found as risk factors of PAD. Longer the duration or higher level exposure to these risk factors has increased the risk of PAD. These findings emphasis the need for routine screening of PAD among patients with the identified risk factors.

     

Cell wall glycopolymers of type strains from three species of the genus <Emphasis Type="Italic">Actinoplanes</Emphasis>

The structures of cell wall glycopolymers from the type strains of three Actinoplanes species were investigated using chemical methods, NMR spectroscopy, and mass spectrometry. Actinoplanes digitatis VKM Ac-649^T contains two phosphate-containing glycopolymers: poly(diglycosyl-1-phosphate) →6)-α-D-GlcpNAc-(1-P-6)-α-D-GlcpN-(1→ and teichoic acid →1)-sn-Gro-(3-P-3)-β-[β-D-GlcpNAc-(1→2]-D-Galp-(1→. Two glycopolymers were identified in A. auranticolor VKM Ac-648^T and A. cyaneus VKM Ac-1095^T: minor polymer–unsubstituted 2,3-poly(glycerol phosphate), widely abundant in actinobacteria (Ac-648^T), and mannan with trisaccharide repeating unit →2)-α-D-Manp-(1→2)-α-D-Manp(1→6)-α-D-Manp-(1→(Ac-1095^T). In addition, both microorganisms contain a teichuronic acid of unique structure containing a pentasaccharide repeating unit with two residues of glucopyranose and three residues of diaminouronic acids in D-manno- and/or D-gluco-configuration. Each of the strains demonstrates peculiarities in the structure of teichuronic acid with respect to the ratio of diaminouronic acids and availability and location of O-methyl groups in glucopyranose residues. All investigated strains contain a unique set of glycopolymers in their cell walls with structures not described earlier for prokaryotes.     

The role of fish-poultry integration on fish growth performance,yields and economic benefits among smallholder farmers in sub-Saharan Africa,Tanzania

Aquaculture practices from sub-Saharan Africa are characterised by low production, owing to improper technology. Production can be increased through integrating fish farming with other existing on-farm activities, particularly livestock husbandry. We assessed the role of fish-poultry integration on all male Nile tilapia, Oreochromis niloticus growth performance, yields and economic benefits among smallholder farmers in sub-Saharan Africa, Tanzania. The study also compared phytoplankton species composition, abundance and biomass between the fish-poultry integration and non-integrated system. After 180 days of the experiment, all male O. niloticus cultured under fish-poultry integration exhibited significantly higher growth rates than those in the non-integrated system (p < 0.05). Gross fish yield (GFY), net fish yield (NFY) and net annual yields (NAY) obtained from fish-poultry integration were significantly higher than those from non-integrated system (p < 0.05). Partial enterprise budget analysis revealed that fish-poultry integration was more profitable than the non-integrated system. Moreover, fish-poultry integrated system produced significantly higher phytoplankton abundance and biomass than those from the non-integrated system. Results demonstrate that rural smallholder farmers can achieve higher growth rate, farm net yields and income by integrating all male O. niloticus with other on-farm activities than practising a stand-alone fish culture system.     

O-Specific Polysaccharides (O-Antigens) of a New Species of Enteric Bacteria Escherichia albertii Closely Related to Escherichia coli

Russian Journal of Bioorganic Chemistry - The data on the structure of O-specific polysaccharides (O-antigens) of all nine known molecular types (potential O-serotypes) of a new type of...     

Structure and serological characterization of the O-antigen of Proteus mirabilis O18 with a phosphocholine-containing oligosaccharide phosphate repeating unit

A phosphorylated, choline-containing polysaccharide was obtained by O-deacylation of the lipopolysaccharide (LPS) of Proteus mirabilis O18 by treatment with aqueous 12% ammonia, whereas hydrolysis with dilute acetic acid resulted in depolymerisation of the polysaccharide chain by the glycosyl phosphate linkage. Treatment of the O-deacylated LPS with aqueous 48% hydrofluoric acid cleaved the glycosyl phosphate group but, unexpectedly, did not affect the choline phosphate group. The polysaccharide and the derived oligosaccharides were studied by NMR spectroscopy, including 2D 1H,1H COSY, TOCSY, ROESY, 1H,13C HMQC and HMQC-TOSCY experiments, along with chemical methods, and the following structure of the pentasaccharide phosphate repeating unit was established: [carbohydrate structure in text] Where ChoP=Phosphocoline Immunochemical studies of the LPS, O-deacylated LPS and partially dephosphorylated pentasaccharide using rabbit polyclonal anti-P. mirabilis O18 serum showed the importance of the glycosyl phosphate group in manifesting the serological specificity of the O18-antigen.     

Structure of the O-polysaccharide of Aeromonas hydrophila O:34; a case of random O-acetylation of 6-deoxy-L-talose

The O-polysaccharide of Aeromonas hydrophila O:34 was obtained by mild-acid degradation of the lipopolysaccharide and studied by chemical methods and NMR spectroscopy before and after O-deacetylation. The polysaccharide was found to contain D-Man, D-GalNAc and 6-deoxy-L-talose (L-6dTal), and the following structure of the tetrasaccharide repeating unit was established [carbohydrate structure see text] where 6dTal(I) is O-acetylated stoichiometrically at position-2 and 6dTal(II) carries no, one or two O-acetyl groups at any positions.     

Structure of an O-acetylated acidic O-specific polysaccharide of Proteus vulgaris O46

An acidic O-specific polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Proteus vulgaris O46 and studied by chemical methods (O-deacetylation, sugar and methylation analyses, partial solvolysis) and 1H and 13C NMR spectroscopy. Solvolysis of the O-deacetylated polysaccharide with trifluoromethanesulfonic acid resulted in a alpha-D-GlcpNAc-(1 --> 3)-D-GlcA disaccharide that demonstrated the usefulness of this reagent for selective cleavage of heteropolysaccharides. The following structure for the polysaccharide was established: --> 4)-alpha-D-Glcp6Ac(1 --> 3)-beta-D-GlcpA4Ac-(1 --> 3)-alpha-D-GlcpNAc-(1 --> 3)-beta-D-GlcpA4Ac-(1 --> where the degree of O-acetylation is approximately 65% at position 6 of Glc and 80-95% at position 4 of GlcA residues.