Activités immunomodulatrice, anti-inflammatoire, antiprurigineuse et tolérogénique induites par I-modulia®, un extrait issu de culture d'Aquaphilus dolomiae, dans les modèles pharmacologiques de dermatite atopique: Immunomodulatory, anti-inflammatory, anti-pruritus and tolerogenic activities induced by I-modulia®, an Aquaphilus dolomiae culture extract, in atopic dermatitis pharmacology models.

Atopic dermatitis (AD) is an inflammatory and pruritic dermatosis of multifactorial origin. Topical steroids are the first line treatment for severe AD however alternatives treatment are increasingly needed. A biological concentrate was elaborated from culture of an Avène aquatic microflora isolate namely Aquaphilus dolomiae. Numerous extracts were evaluated in relevant AD in vitro models with human keratinocytes. Among these extracts, a particular one I-modulia® was found to be remarkable in terms of pharmacological activities: innate immunity modulating by agonizing Toll like receptor (TLR)2, TLR4 and TLR5, induction of anti-microbial peptides, inhibition of cytokines characteristics of T helper (Th)1, Th2 and Th17 responses, inhibition of Protease-activated-receptor (PAR) 2 and Thymic-stromal-lymphopoeitin (TSLP) both being known to be upregulated in pruritus. Additionally, when human dendritic cells (DC) were stimulated in vitro by Staphylococcus aureus secretomes from AD children lesions, I-modulia® was capable to induce IL-10 secretion to activate regular T lymphocytes and rendered DC tolerogenic. I-modulia®, extract of biotech origin incorporated in emollient, displays anti-inflammatory, anti-pruritus activities, restores homeostasis immune and ameliorates AD in young infant.

Cloning, Expression and 3D Structure Prediction of Chitinase from Chitinolyticbacter meiyuanensis SYBC-H1.

Two CHI genes from Chitinolyticbacter meiyuanensis SYBC-H1 encoding chitinases were identified and their protein 3D structures were predicted. According to the amino acid sequence alignment, CHI1 gene encoding 166 aa had a structural domain similar to the GH18 type II chitinase, and CHI2 gene encoding 383 aa had the same catalytic domain as the glycoside hydrolase family 19 chitinase. In this study, CHI2 chitinase were expressed in Escherichia coli BL21 cells, and this protein was purified by ammonium sulfate precipitation, DEAE-cellulose, and Sephadex G-100 chromatography. Optimal activity of CHI2 chitinase occurred at a temperature of 40 °C and a pH of 6.5. The presence of metal ions Fe(3+), Fe(2+), and Zn(2+) inhibited CHI2 chitinase activity, while Na⁺ and K⁺ promoted its activity. Furthermore, the presence of EGTA, EDTA, and ß-mercaptoethanol significantly increased the stability of CHI2 chitinase. The CHI2 chitinase was active with p-NP-GlcNAc, with the Km and Vm values of 23.0 µmol/L and 9.1 mM/min at a temperature of 37 °C, respectively. Additionally, the CHI2 chitinase was characterized as an N-acetyl glucosaminidase based on the hydrolysate from chitin. Overall, our results demonstrated CHI2 chitinase with remarkable biochemical properties is suitable for bioconversion of chitin waste.

Application of matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of the fastidious pediatric pathogens Aggregatibacter, Eikenella, Haemophilus, and Kingella.

The accuracy of matrix-assisted laser desorption-ionization time of flight mass spectrometry (MALDI-TOF MS) in the identification of Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, and Kingella (HACEK) species was compared to that of phenotypic methods (Remel RapID and Vitek 2). Overall, Vitek MS correctly identified more isolates, incorrectly identified fewer isolates, and failed to identify fewer isolates than both phenotypic methods.

Structure of the lipopolysaccharide isolated from the novel species Uruburuella suis.

Uruburuella suis is a novel species isolated from lungs and heart of pigs with pneumonia and pericarditis. Phenotypic and phylogenetic evidences showed that it represented a hitherto unknown subline within the family Neisseriaceae. In the present work we defined the whole structure of the LPS isolated from Uruburuella suis. The structural determination, which was achieved by chemical, spectroscopic and spectrometric approaches, indicates a novel rough type lipopolysaccharide rich in negatively charged groups in the lipid A-inner core region. The elucidation of the structural features of the LPS from Uruburuella suis is a first step toward the comprehension of the characteristics of the cell envelope in such new and interesting microorganisms.

Chitinibacter suncheonensis sp. nov., a chitinolytic bacterium from a mud flat in Suncheon Bay.

A chitinolytic bacterium, designated strain SK16(T), was isolated from a mud flat in Suncheon Bay, Republic of Korea. Strain SK16(T) is Gram-negative, strictly aerobic, motile by a polar flagellum, and short rod-shaped. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strain belonged to the genus Chitinibacter and was most closely related to Chitinibacter tainanensis S1(T) (98.2% similarity). DNA-DNA hybridization analyses showed a low association value of 20.45±4.08% between them. The major cellular fatty acids, the G+C content of the genomic DNA, and the predominant quinone of the strain were summed feature 3 (iso-C(15:0) 2-OH and/or C(16:1) ω7c; 50.5%) and C(12:0) (12.5%), 52.26 mol%, and Q-8, respectively. Based on the phylogenetic, chemotaxonomic, and phenotypic properties, strain SK16(T) represents a novel species of the genus Chitinibacter, for which the name Chitinibacter suncheonensis sp. nov. is proposed. The type strain is SK16(T) (=KCTC 23839(T) =DSM 25421(T)).

Vogesella lacus sp. nov., isolated from a soft-shell turtle culture pond.

A non-pigmented, Gram-negative, aerobic, rod-shaped bacterium, strain GR13(T), was isolated using nutrient agar from a water sample from a pond used for the culture of soft-shell turtles (Trionyx sinensis), Pingtung County, Taiwan. 16S rRNA gene sequence studies indicated that the novel strain formed a monophyletic branch at the periphery of the evolutionary radiation occupied by the genus Vogesella. Its closest neighbours were Vogesella indigofera ATCC 19706(T) and Vogesella perlucida DS-28(T) (both with 97.4 % gene sequence similarity). The novel isolate could be distinguished from these species by several phenotypic characteristics. The predominant fatty acids were summed feature 3 (C(16 : 1)omega7c and/or C(15 : 0) iso 2-OH; 60 %), C(16 : 0) (13.6 %) and C(18 : 1)omega7c (12.5 %). The DNA G+C content of strain GR13(T) was 63 mol%. The DNA-DNA hybridization values for the novel strain with V. indigofera and V. perlucida were <25 %. On the basis of the 16S rRNA gene sequence analysis and the chemotaxonomic and physiological data, it is concluded that strain GR13(T) represents a novel species in the genus Vogesella, for which the name Vogesella lacus sp. nov. is proposed. The type strain is GR13(T) (=BCRC 17836(T)=LMG 24504(T)).

Reclassification of Aquaspirillum itersonii and Aquaspirillum peregrinum as Novispirillum itersonii gen. nov., comb. nov. and Insolitispirillum peregrinum gen. nov., comb. nov.

Phylogenetic analysis based on 16S rRNA gene sequences showed that Aquaspirillum itersonii and Aquaspirillum peregrinum form distinct phylogenetic lineages within the Alphaproteobacteria, whereas Aquaspirillum serpens, the type species of the genus Aquaspirillum, belongs to the Betaproteobacteria. A. itersonii and A. peregrinum exhibited 16S rRNA gene sequence similarity values of 82.0-82.4 % to the type strain of A. serpens and of 91.8-92.0 % to each other. A. itersonii and A. peregrinum were clearly distinguishable from A. serpens by differences in ubiquinone types and fatty acid profiles. A. itersonii subsp. itersonii LMG 4337(T) and A. itersonii subsp. nipponicum LMG 7370(T) contained Q-10 as the predominant ubiquinone, and A. peregrinum subsp. peregrinum LMG 4340(T) and A. peregrinum subsp. integrum LMG 5407(T) contained Q-9 as the predominant ubiquinone, whereas A. serpens LMG 3734(T) had Q-8 as the predominant ubiquinone. A. itersonii and A. peregrinum were also distinguishable from A. serpens by some differences in the fatty acid composition, including major fatty acids and hydroxy fatty acids. On the basis of these data, A. itersonii and A. peregrinum should be reclassified into two novel genera and species, for which the names Novispirillum itersonii gen. nov., comb. nov. and Insolitispirillum peregrinum gen. nov., comb. nov., respectively, are proposed.

Andreprevotia chitinilytica gen. nov., sp. nov., isolated from forest soil from Halla Mountain, Jeju Island, Korea.

A motile, Gram-negative, rod-shaped bacterium, designated strain JS11-7(T), was isolated from forest soil from Halla Mountain, Jeju Island, Korea. It grew optimally at 28 degrees C, pH 6-7 and in the presence of 0-2 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain JS11-7(T) belongs to the family Neisseriaceae, with Silvimonas terrae as its closest relative (95.0 % similarity). It contained Q-8 as the predominant quinone and summed feature 3 (comprising iso-C(15 : 0) 2-OH and/or C(16 : 1) omega 6c), C(16 : 0) and C(18 : 1) omega 7c as the major fatty acids. The DNA G+C content was 62 mol%. On the basis of phenotypic and genotypic characteristics and the results of 16S rRNA gene sequence analysis, strain JS11-7(T) represents a novel genus and species, for which the name Andreprevotia chitinilytica gen. nov., sp. nov. is proposed. The type species is Andreprevotia chitinilytica and the type strain is JS11-7(T) (=KACC 11608(T)=DSM 18519(T)).

Biochemical analysis of lactoferrin receptors in the Neisseriaceae: identification of a second bacterial lactoferrin receptor protein.

Bacterial transferrin receptors that have been described in the families Pasteurellaceae and Neisseriaceae are composed of two receptor proteins, transferrin binding proteins 1 and 2 (Tbp1 and Tbp2). In contrast, bacterial lactoferrin receptors have only been described for human pathogens in the family Neisseriaceae, and were believed to consist of a single protein, Lbp1, which is highly homologous to Tbp1. We describe a modified affinity isolation procedure that facilities isolation of a second lactoferrin receptor protein Lbp2 (a presumptive Tbp2 homologue) from Neisseria meningitidis, Moraxella catarrhalis and Moraxella bovis using immobilized lactoferrin. Antiserum specific for either the M. catarrhalis Tbp1+2 molecules, the M. catarrhalis Lbp1 molecule, or for a commercial preparation of human lactoferrin did not react on western blots with the same organisms' affinity purified Lbp2. In addition, the M. catarrhalis Lbp2 could be isolated in a functional form without contaminating Lbp1 or Tbp1+2. We also demonstrate that the bovine pathogen, M. bovis, produces functional transferrin and lactoferrin receptors specific for the bovine forms of these glycoproteins. A putative lbpB gene, recently speculated to reside immediately upstream of the N. meningitidis Lbp1 structural gene, lbpA, likely encodes the newly isolated Lbp2 protein from this bacterial species.

Differentiation of selected members of the family Neisseriaceae (Alysiella, Eikenella, Kingella, Simonsiella and CDC groups EF-4 and M-5) by carbohydrate fingerprints and selected phenotypic features.

On the basis of nucleic acid relationships, the family Neisseriaceae consists of the genera Neisseria, Kingella, Simonsiella and of Alysiella filiformis, Eikenella corrodens, and the CDC groups EF-4 and M-5. Differentiation, especially of the new members of the family, by conventional phenotypic characteristics is difficult and in some cases leads to doubtful results. On the other hand, cellular components proved to be suitable for the characterization of bacterial taxa. We investigated the cellular carbohydrates derived from whole cell hydrolysates of the above mentioned taxa with the exception of Neisseria by gas chromatography/mass-spectrometry. The analysis revealed characteristic patterns for all taxa considered, although with some species of which only few strains were investigated so far only preliminary results could be established. With the method used, the carbohydrate analysis could be completed within six hours starting from a pure culture. All strains investigated exhibited a common pattern with ribose, arabinose, glucose, and galactose. Qualitative and quantitative differences in contents of fucose, sorbose, rhamnose, threose, heptose, galactosamine and an amino sugar similar to glucosamine discriminated members of the taxa investigated. To achieve a taxonomically precise differentiation of the species investigated by conventional phenotypic features as available in commercial rapid test kits, these tests should be completed by the carbohydrate analysis technique presented.

Structural heterogeneity of the lipopolysaccharides of the Neisseriaceae.

Lipopolysaccharides from 5 different genera of the Neisseriaceae were analyzed on sodium dodecylsulfate-polyacrylamide gel electrophoresis, and visualized by silver staining. Significant heterogeneity in the banding patterns was observed with some of the strains producing only low molecular mass molecules and others producing O-repeating units. All genera examined except Branhamella contained strains that were able to produce an O-repeating side chain on their lipopolysaccharides. The ability to produce the repeating subunit did not correlate with the presence of plasmids.