scholarly journals Characterization of Awp14, A Novel Cluster III Adhesin Identified in a High Biofilm-Forming Candida glabrata Isolate

2021 ◽  
Vol 11 ◽  
Author(s):  
Jordan Fernández-Pereira ◽  
María Alvarado ◽  
Emilia Gómez-Molero ◽  
Henk L. Dekker ◽  
María Teresa Blázquez-Muñoz ◽  
...  
Keyword(s):  
Candida Glabrata ◽  
Venous Catheter ◽  
Clinical Strain ◽  
Proteomics Data ◽  
Fungal Cell ◽  
Binding Domains ◽  
First Time ◽  
Mutant Cells

Candida glabrata is among the most prevalent causes of candidiasis. Unlike Candida albicans, it is not capable of changing morphology between yeast and hyphal forms but instead has developed other virulence factors. An important feature is its unprecedented large repertoire of predicted cell wall adhesins, which are thought to enable adherence to a variety of surfaces under different conditions. Here, we analyzed the wall proteome of PEU1221, a high biofilm-forming clinical strain isolated from an infected central venous catheter, under biofilm-forming conditions. This isolate shows increased incorporation of putative adhesins, including eight proteins that were not detected in walls of reference strain ATCC 2001, and of which Epa22, Awp14, and Awp2e were identified for the first time. The proteomics data suggest that cluster III adhesin Awp14 is relatively abundant in PEU1221. Phenotypic studies with awp14Δ deletion mutants showed that Awp14 is not responsible for the high biofilm formation of PEU1221 onto polystyrene. However, awp14Δ mutant cells in PEU1221 background showed a slightly diminished binding to chitin and seemed to sediment slightly slower than the parental strain suggesting implication in fungal cell-cell interactions. By structural modeling, we further demonstrate similarity between the ligand-binding domains of cluster III adhesin Awp14 and those of cluster V and VI adhesins. In conclusion, our work confirms the increased incorporation of putative adhesins, such as Awp14, in high biofilm-forming isolates, and contributes to decipher the precise role of these proteins in the establishment of C. glabrata infections.

scholarly journals Molecular Characterization of the Gene Encoding a New AmpC β-Lactamase in a Clinical Strain of Acinetobacter Genomic Species 3

2004 ◽  
Vol 48 (4) ◽  
pp. 1374-1378 ◽  
Author(s):  
Alejandro Beceiro ◽  
Lourdes Dominguez ◽  
Anna Ribera ◽  
Jordi Vila ◽  
Francisca Molina ◽  
...  
Keyword(s):  
Nucleotide Sequence ◽  
Molecular Characterization ◽  
Biochemical Properties ◽  
Clinical Strain ◽  
The Novel ◽  
Gene Encoding ◽  
Genomic Species ◽  
First Time

ABSTRACT A presumptive chromosomal cephalosporinase (pI, 9.0) from a clinical strain of Acinetobacter genomic species 3 (AG3) is reported. The nucleotide sequence of this β-lactamase shows for the first time the gene encoding an AmpC enzyme in AG3. In addition, the biochemical properties of the novel AG3 AmpC β-lactamase are reported

scholarly journals Molecular analysis of the microflora in chronic venous leg ulceration

2003 ◽  
Vol 52 (4) ◽  
pp. 365-369 ◽  
Author(s):  
K.E. Hill ◽  
C.E. Davies ◽  
M.J. Wilson ◽  
P. Stephens ◽  
K.G. Harding ◽  
...  
Keyword(s):  
Individual Species ◽  
Venous Leg Ulcer ◽  
Bacterial Populations ◽  
Cultural Methods ◽  
Rdna Sequences ◽  
Oral Microflora ◽  
16S Rdna Sequences ◽  
First Time

There is growing evidence to suggest that the resident microflora of chronic venous leg ulcers impairs cellular wound-healing responses, thereby playing an important role in maintaining the non-healing phenotype of many of these wounds. The significance of individual species of bacteria will remain unclear until it is possible to characterize fully the microflora of such lesions. The limitations and biases of culture-based microbiology are being realized and the subsequent application of molecular methods is revealing greater diversity within mixed bacterial populations than that demonstrated by culture alone. To date, this approach has been limited to a small number of systems, including the oral microflora. Here, for the first time, the comprehensive characterization of the microflora present in the tissue of a chronic venous leg ulcer is described by the comparison of 16S rDNA sequences amplified directly from the wound tissue with sequences obtained from bacteria that were isolated by culture. The molecular approach demonstrated significantly greater bacterial diversity than that revealed by culture. Furthermore, sequences were retrieved that may possibly represent novel species of bacteria. It is only by the comprehensive analysis of the wound microflora by both molecular and cultural methods that it will be possible to further our understanding of the role of bacteria in this important condition.

Phonons in deformable microporous crystalline solids

2019 ◽  
Vol 234 (7-8) ◽  
pp. 513-527 ◽  
Author(s):  
Bogdan Kuchta ◽  
Filip Formalik ◽  
Justyna Rogacka ◽  
Alexander V. Neimark ◽  
Lucyna Firlej
Keyword(s):  
Periodic Structures ◽  
Structural Transformations ◽  
Crystalline Solids ◽  
Predictive Tool ◽  
Crystalline Materials ◽  
Numerical Tools ◽  
Collective Vibrations ◽  
First Time

Abstract Phonons are quantum elastic excitations of crystalline solids. Classically, they correspond to the collective vibrations of atoms in ordered periodic structures. They determine the thermodynamic properties of solids and their stability in the case of structural transformations. Here we review for the first time the existing examples of the phonon analysis of adsorption-induced transformations occurring in microporous crystalline materials. We discuss the role of phonons in determining the mechanism of the deformations. We point out that phonon-based methodology may be used as a predictive tool in characterization of flexible microporous structures; therefore, relevant numerical tools must be developed.

scholarly journals Characterization of hybrid proteins consisting of the catalytic domains of Clostridium and Ruminococcus endoglucanases, fused to Pseudomonas non-catalytic cellulose-binding domains

1991 ◽  
Vol 279 (3) ◽  
pp. 787-792 ◽  
Author(s):  
D M Poole ◽  
A J Durrant ◽  
G P Hazlewood ◽  
H J Gilbert
Keyword(s):  
Catalytic Domain ◽  
Binding Capacity ◽  
Binding Domains ◽  
Hybrid Proteins ◽  
C Terminus ◽  
N Terminus ◽  
Fusion Enzymes ◽  
Cellulose Binding

The N-terminal 160 or 267 residues of xylanase A from Pseudomonas fluorescens subsp. cellulosa, containing a non-catalytic cellulose-binding domain (CBD), were fused to the N-terminus of the catalytic domain of endoglucanase E (EGE') from Clostridium thermocellum. A further hybrid enzyme was constructed consisting of the 347 N-terminal residues of xylanase C (XYLC) from P. fluorescens subsp. cellulosa, which also constitutes a CBD, fused to the N-terminus of endoglucanase A (EGA) from Ruminococcus albus. The three hybrid enzymes bound to insoluble cellulose, and could be eluted such that cellulose-binding capacity and catalytic activity were retained. The catalytic properties of the fusion enzymes were similar to EGE' and EGA respectively. Residues 37-347 and 34-347 of XYLC were fused to the C-terminus of EGE' and the 10 amino acids encoded by the multiple cloning sequence of pMTL22p respectively. The two hybrid proteins did not bind cellulose, although residues 39-139 of XYLC were shown previously to constitute a functional CBD. The putative role of the P. fluorescens subsp. cellulosa CBD in cellulase action is discussed.

scholarly journals A small mitochondrial protein present in myzozoans is essential for malaria transmission

Open Biology ◽  
2016 ◽  
Vol 6 (4) ◽  
pp. 160034 ◽  
Author(s):  
Dennis Klug ◽  
Gunnar R. Mair ◽  
Friedrich Frischknecht ◽  
Ross G. Douglas
Keyword(s):  
Drug Targets ◽  
Mitochondrial Protein ◽  
Sister Group ◽  
Developmental Defect ◽  
Mitochondrial Mass ◽  
First Time ◽  
Potential Drug Targets ◽  
Identification And Characterization

Myzozoans (which include dinoflagellates, chromerids and apicomplexans) display notable divergence from their ciliate sister group, including a reduced mitochondrial genome and divergent metabolic processes. The factors contributing to these divergent processes are still poorly understood and could serve as potential drug targets in disease-causing protists. Here, we report the identification and characterization of a small mitochondrial protein from the rodent-infecting apicomplexan parasite Plasmodium berghei that is essential for development in its mosquito host. Parasites lacking the gene mitochondrial protein ookinete developmental defect ( mpodd ) showed malformed parasites that were unable to transmit to mosquitoes. Knockout parasites displayed reduced mitochondrial mass without affecting organelle integrity, indicating no role of the protein in mitochondrial biogenesis or morphology maintenance but a likely role in mitochondrial import or metabolism. Using genetic complementation experiments, we identified a previously unrecognized Plasmodium falciparum homologue that can rescue the mpodd(−) phenotype, thereby showing that the gene is functionally conserved. As far as can be detected, mpodd is found in myzozoans, has homologues in the phylum Apicomplexa and appears to have arisen in free-living dinoflagellates. This suggests that the MPODD protein has a conserved mitochondrial role that is important for myzozoans. While previous studies identified a number of essential proteins which are generally highly conserved evolutionarily, our study identifies, for the first time, a non-canonical protein fulfilling a crucial function in the mitochondrion during parasite transmission.

scholarly journals Isolation and Characterization of Cryptococcus neoformans Spores Reveal a Critical Role for Capsule Biosynthesis Genes in Spore Biogenesis

2009 ◽  
Vol 8 (4) ◽  
pp. 595-605 ◽  
Author(s):  
Michael R. Botts ◽  
Steven S. Giles ◽  
Marcellene A. Gates ◽  
Thomas R. Kozel ◽  
Christina M. Hull
Keyword(s):  
Cryptococcus Neoformans ◽  
Fungal Pathogens ◽  
Critical Role ◽  
Spore Formation ◽  
Yeast Cells ◽  
Isolation And Characterization ◽  
Specific Configuration ◽  
First Time

ABSTRACT Spores are essential particles for the survival of many organisms, both prokaryotic and eukaryotic. Among the eukaryotes, fungi have developed spores with superior resistance and dispersal properties. For the human fungal pathogens, however, relatively little is known about the role that spores play in dispersal and infection. Here we present the purification and characterization of spores from the environmental fungus Cryptococcus neoformans. For the first time, we purified spores to homogeneity and assessed their morphological, stress resistance, and surface properties. We found that spores are morphologically distinct from yeast cells and are covered with a thick spore coat. Spores are also more resistant to environmental stresses than yeast cells and display a spore-specific configuration of polysaccharides on their surfaces. Surprisingly, we found that the surface of the spore reacts with antibodies to the polysaccharide glucuronoxylomannan, the most abundant component of the polysaccharide capsule required for C. neoformans virulence. We explored the role of capsule polysaccharide in spore development by assessing spore formation in a series of acapsular strains and determined that capsule biosynthesis genes are required for proper sexual development and normal spore formation. Our findings suggest that C. neoformans spores may have an adapted cell surface that facilitates persistence in harsh environments and ultimately allows them to infect mammalian hosts.

scholarly journals Immunological changes in growing mice fed on diets containing casein or peas (Pisum sativum var. Belinda) as the source of protein

1995 ◽  
Vol 73 (1) ◽  
pp. 87-97 ◽  
Author(s):  
J.Alfredo Martínez ◽  
M. Luisa Esparza ◽  
Jesús Larralde
Keyword(s):  
Pisum Sativum ◽  
Individual Performance ◽  
Gastrointestinal Disorders ◽  
Antigenic Proteins ◽  
Poor Individual ◽  
First Time ◽  
Different Sources

The effects of two different sources of protein: peas (Pisum sativum var. Belinda) and casein on immunocompetence, nutritional utilization and growth performance have been investigated in recently weaned mice. Feeding these animals on a pea diet resulted in an impairment in growth and significant decreases in the weights of liver, muscle, kidneys and femur, while intestine weights increased. No differences in food consumption were observed, but food conversion efficiency (food intake: weight gain) was increased in pea-fed animals compared with those offered the casein diet. Packed cell volume and serum Fe and Zn levels fell significantly after legume-protein intake, and, by contrast, Cu values increased slightly. Serum albumin levels showed a statistically significant reduction in mice fed on the diet containing peas. However, y-globulins and immunoglobulin G titres were markedly increased. The characterization of spleen-cell subsets using monoclonal antibodies revealed a significantly higher percentage of T-lymphocytes in the pea group compared with casein-fed animals, while no changes were observed in the proportions of B-lymphocytes and macrophages. In vitro mitogenic responses to phytohaemagglutinin, concanavalin A and Escherichia coli lipopolysaccharide S were slightly, but not significantly, lower in the pea-fed animals. Our results describe, apparently for the first time in mice, some immunological disturbances after peak intake. These results may lead to a better understanding of the possible role of antigenic proteins in gastrointestinal disorders and the poor individual performance after legume intake.

scholarly journals Restoration of a tumorigenic phenotype by beta 2-microglobulin transfection to EL-4 mutant cells.

1992 ◽  
Vol 175 (3) ◽  
pp. 843-846 ◽  
Author(s):  
R Glas ◽  
K Sturmhöfel ◽  
G J Hämmerling ◽  
K Kärre ◽  
H G Ljunggren
Keyword(s):  
Transfected Cells ◽  
Histocompatibility Complex ◽  
Tumorigenic Potential ◽  
Immunological Recognition ◽  
Beta 2 ◽  
Beta 2 Microglobulin ◽  
First Time ◽  
Mutant Cells

It has frequently been suggested that loss of beta 2-microglobulin (beta 2m) in tumor cells may lead to malignant progression due to escape from immunological recognition. Here, we directly tested the role of beta 2m expression in tumorigenicity. A beta 2 m loss mutant (C4.4-25-), selected from the murine lymphoma EL-4, showed a marked reduction in tumorigenicity as compared with EL-4 in normal C57B1/6 (B6) mice. The reduced tumorigenicity was directly related to beta 2 m expression. Transfection of an intact murine beta 2m gene markedly increased the tumorigenic potential. The reduced tumorigenicity of C4.4-25- compared with beta 2m transfected cells was observed also in athymic B6 nu/nu mice, but was abolished in B6 mice depleted of natural killer (NK) 1.1-positive cells. These results show that restoration of beta 2m expression can promote tumorigenicity and demonstrate for the first time that induction of major histocompatibility complex class I expression by transfection can lead to escape from NK cells in vivo.

scholarly journals Characterization of the secretory profile and exosomes of limbal stem cells in the canine species

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244327
Author(s):  
Antonio J. Villatoro ◽  
Cristina Alcoholado ◽  
María del Carmen Martín-Astorga ◽  
Gustavo Rico ◽  
Viviana Fernández ◽  
...  
Keyword(s):  
Stem Cells ◽  
Ocular Surface ◽  
Inhibitory Effect ◽  
Proteomic Profile ◽  
Limbal Stem Cells ◽  
High Concentrations ◽  
First Time

Limbal stem cells (LSCs) are a quiescent cell population responsible for the renewal of the corneal epithelium. Their deficiency is responsible for the conjunctivization of the cornea that is seen in different ocular pathologies, both in humans and in the canine species. The canine species represents an interesting preclinical animal model in ocular surface pathologies. However, the role of LSCs in physiological and pathological conditions in canine species is not well understood. Our objective was to characterize for the first time the soluble factors and the proteomic profile of the secretome and exosomes of canine LSCs (cLSCs). In addition, given the important role that fibroblasts play in the repair of the ocular surface, we evaluated the influence of the secretome and exosomes of cLSCs on their proliferation in vitro. Our results demonstrated a secretory profile of cLSCs with high concentrations of MCP-1, IL-8, VEGF-A, and IL-10, as well as significant production of exosomes. Regarding the proteomic profile, 646 total proteins in the secretome and 356 in exosomes were involved in different biological processes. Functionally, the cLSC secretome showed an inhibitory effect on the proliferation of fibroblasts in vitro, which the exosomes did not. These results open the door to new studies on the possible use of the cLSC secretome or some of its components to treat certain pathologies of the ocular surface in canine species.

scholarly journals Significant and conflicting correlation of IL-9 with Prevotella and Bacteroides in human colorectal cancer

2020 ◽  
Author(s):  
E Niccolai ◽  
E Russo ◽  
S Baldi ◽  
F Ricci ◽  
G Nannini ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Immune Response ◽  
Multinomial Regression ◽  
Tnf Α ◽  
Ifn Γ ◽  
Inflammatory Profile ◽  
Infiltrating Lymphocytes ◽  
First Time

ABSTRACTBackgroundColorectal cancer (CRC) is a widespread disease that represents an example of chronic inflammation-associated tumor. In fact, the immune system, besides protecting the host from developing tumors, can support the CRC progression. In this scenario, the gut microbiota (GM) is essential to modulate immune responses and a dysbiotic condition can favor chronic/abnormal immune activation that support the tumor growth. GM can elicit the production of cytokines, influencing the immunostimulatory or immunosuppressive reactions, such as the tendency to mount Th1, Th17, Tregs or Th9 responses that play different roles towards colon cancer. Paradigmatic is the role of IL-9 that can both promote tumor progression in hematological malignancies and inhibit tumorigenesis in solid cancers. Therefore, to investigate the microbiota-immunity axis in CRC patients is crucial to well understand the cancer development with positive relapses in prevention and treatment.AimThe cellular and molecular characterization of the immune response and the evaluation of GM composition in healthy and tumor mucosa, focusing on the correlation between cytokines’ profile and GM signature.MethodsWe collected tumoral (CRC) and healthy (CRC-S) mucosa samples of 45 CRC patients. For each sample, we characterized the Tissue Infiltrating Lymphocytes (TIL)’s subset profile and the GM composition. In addition, in 14 CRC patients, we evaluated the CRC and CRC-S molecular inflammatory response (26 cytokines/chemokines) and we correlated this profile with GM composition using the Dirichlet Multinomial Regression.ResultsThe analysis of T cells subsets distribution showed that CRC samples displayed higher percentages of Th17, Th2, Tregs, Tc17, Tc1/Tc17, and Tcreg, compared to CRC-S. Notably, also the number of Th9 was higher, even if not significantly, in CRC tissue compared to healthy one. In addition, we found that MIP-1α, IL-1β, IL-2, IP-10, IL-6, IL-8, IL-17A, IFN-γ, TNF-α, MCP-1, IL-1α, P-selectin and IL-9 were significantly increased in CRC compared to CRC-S. Moreover, the GM analysis revealed that CRC samples had significantly higher levels of Fusobacteria, Proteobacteria, Fusobacterium, Ruminococcus2 (Lachnospiraceae family) and Ruminococcus (Ruminococcaceae family) than CRC-S. Finally, we found that the abundance of Prevotella spp in CRC samples was negatively correlated with IL-17A and positively with IL-9. In addition, the abundance of Bacteroides and Escherichia/Shigella species in CRC samples showed a negative association with IL-9 and IP-10 respectively.ConclusionsOur data show a clear dissimilarity of inflammatory profile and GM composition between the tumor and the adjacent healthy tissue, displaying the generation of a peculiar CRC microenvironment. Interestingly, relating the tissue cytokine profile with the GM composition, we confirmed the presence of a bidirectional crosstalk between the immune response and the host’s commensal microorganisms; in detail, we documented for the first time that Prevotella spp. and Bacteroides spp. are correlated (positively and negatively, respectively) with the IL-9, whose role in CRC development is still debated.

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