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118 results on '"Larcher, Gérald"'

1. Microbial antioxidant defense enzymes

Author

Staerck, Cindy, Gastebois, Amandine, Vandeputte, Patrick, Calenda, Alphonse, Larcher, Gérald, Gillmann, Louiza, Papon, Nicolas, Bouchara, Jean-Philippe, and Fleury, Maxime J.J.

Published
2017
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5. Synthesis, Characterization, Antibacterial and Antifungal Activities Evaluation of Metal Complexes With Benzaldehyde‐4‐methylthiosemicarbazone Derivatives

Author

Jaafar, Amani, primary, Mansour, Najwa, additional, Fix‐Tailler, Adeline, additional, Allain, Magali, additional, Faour, Wissam H., additional, Shebaby, Wassim N., additional, Tokajian, Sima, additional, El‐Ghayoury, Abdelkrim, additional, Naoufal, Daoud, additional, Larcher, Gérald, additional, and Ibrahim, Ghassan, additional

Published
2022
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6. Spider bites in France: Epidaemiology of cases occurring in 10 years in metropolitan France

Author

Le Roux, Gael, Richard, Virginie, Larcher, Gérald, Sinno-Tellier, Sandra, Labadie, Magali, de Haro, Luc, Descatha, Alexis, Institut de recherche en santé, environnement et travail (Irset), Université d'Angers (UA)-Université de Rennes (UR)-École des Hautes Études en Santé Publique [EHESP] (EHESP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), Centre Antipoison et Toxicovigilance du Grand Ouest (Angers) (CAPTV Angers), Centre Hospitalier Universitaire d'Angers (CHU Angers), PRES Université Nantes Angers Le Mans (UNAM)-PRES Université Nantes Angers Le Mans (UNAM), Université d'Angers (UA), Direction des alertes et des vigilances sanitaires (DAVS), Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES), Centre antipoison et de toxicovigilance (Bordeaux) (CAPTV Bordeaux), CHU Bordeaux [Bordeaux], Centre antipoison et de toxicovigilance (Marseille) (CAPTV Marseille), Assistance Publique - Hôpitaux de Marseille (APHM), PRES Université Nantes Angers Le Mans (UNAM), Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique )-Institut National de la Santé et de la Recherche Médicale (INSERM)-École des Hautes Études en Santé Publique [EHESP] (EHESP)-Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Université d'Angers (UA)

Subjects
genetic structures, [SDV]Life Sciences [q-bio], MESH: Phobic Disorders, MESH: Spiders, complex mixtures, MESH: Spider Bites, 030207 dermatology & venereal diseases, 03 medical and health sciences, yellow sac spider, 0302 clinical medicine, loxoscelism, Animals, MESH: Animals, Ecology, Evolution, Behavior and Systematics, spider bites, Retrospective Studies, 0303 health sciences, General Veterinary, 030311 toxicology, Spiders, MESH: Retrospective Studies, MESH: France, Phobic Disorders, nervous system, Insect Science, Parasitology, France, latrodectism
Abstract

French PCC Research Group; International audience; Spiders are often wrongly designated as responsible for cutaneous eruptions. We aim to describe spider bites and the spider species implicated in metropolitan France. A retrospective observational study was conducted for all reported cases of spider bites from 2007 to 2018 extracted from the French Poison Control Centers (PCCs) information system, after exclusion of non-native spiders. We described identification of the spider, level of certainty of the bite, symptoms and severity of cases. 1194 cases of spider bites met the inclusion criteria. The average age of the patients was 36.9 +/- 19.8 years. Identification of the species or at least that a spider was implicated was only possible in 346 cases (29.0%). Loxosceles were involved in 53 cases (4.4%), Latrodectus in 46 cases (3.9%) and Cheiracanthium in 35 cases (2.9%). In one third of cases, the involved spider was not known to be present where the bite occurred. Where most of the patients (n = 1111, 93%) reported at least one cutaneous symptom, most of the symptoms were neurological. The bite was considered proven in only 242 cases (20%). Despite the efforts of arachnologists to educate the public, the fear of spiders is still alive in France, where spider bite is rare with low severity and often unproven.

Published
2022

11. Synthesis, characterization, antifungal and antibacterial activities evaluation of copper (II), zinc (II) and cadmium (II) chloride and bromide complexes with new ( E ) ‐ 1‐(3,4‐dimethoxybenzylidene)‐4‐methylthiosemicarbazone ligand

Author

Jaafar, Amani, primary, Fix‐Tailler, Adeline, additional, Mansour, Najwa, additional, Allain, Magali, additional, Shebaby, Wassim N., additional, Faour, Wissam H., additional, Tokajian, Sima, additional, El‐Ghayoury, Abdelkrim, additional, Naoufal, Daoud, additional, Bouchara, Jean‐Philippe, additional, Larcher, Gérald, additional, and Ibrahim, Ghassan, additional

Published
2020
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16. Lleida Bat Lyssavirus isolation in Miniopterus schreibersii in France.

Author

Picard‐Meyer, Evelyne, Beven, Veronique, Hirchaud, Edouard, Guillaume, Cédric, Larcher, Gérald, Robardet, Emmanuelle, Servat, Alexandre, Blanchard, Yannick, and Cliquet, Florence

Subjects
LYSSAVIRUS, MINIOPTERUS schreibersii, RABIES, RNA, NUCLEOTIDES
Abstract

Bat rabies cases are attributed in Europe to five different Lyssavirus species of 16 recognized Lyssavirus species causing rabies. One of the most genetically divergent Lyssavirus spp. has been detected in a dead Miniopterus schreibersii bat in France. Brain samples were found positive for the presence of antigen, infectious virus and viral RNA by classical virological methods and molecular methods respectively. The complete genome sequence was determined by next‐generation sequencing. The analysis of the complete genome sequence confirmed the presence of Lleida bat lyssavirus (LLEBV) in bats in France with 99.7% of nucleotide identity with the Spanish LLEBV strain (KY006983). [ABSTRACT FROM AUTHOR]

Published
2019
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18. The Enzymatic Activity and Molecular Characterization of a Secreted Subtilisin-Like Protease in Microsporum gypseum and Trichophyton vanbreuseghemii

Author

Moallaei, Hossein, Zaini, F., Rezaie, S., Nourbakhsh, F., Larcher, Gérald, Institut de la Vision, Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Groupe d'Étude des Interactions Hôte-Pathogène (GEIHP), Université d'Angers (UA), and Univ Angers, Okina

Subjects
[SDV] Life Sciences [q-bio], Keratinases, lcsh:Public aspects of medicine, [SDV]Life Sciences [q-bio], fungi, Subtilisin-like protease, Trichophyton vanbreuseghemii, lcsh:RA1-1270, Microsporum gypseum
Abstract

"nBackground: Subtilisin -like proteases are the group of proteases including keratinases found in dermatophytes which de­graded keratin. Determination of the proteases activity of Trichophyton vanbreuseghemii isolates which were obtained from soil and clinical and soil isolates of Microsporum gypseum in Iran and characterization of their genome were aim of present study."nMethods: Ezymatic activity was determined by use of chromogenic substrates. The genes, which coded subtilisin-like pro­teases in above-mentioned dermatophytes, was identified and amplified by using specific primers in PCR."nResults: The highest yield of enzyme production was observed in only one isolate of T. vanbreuseghemii Ir-84 whereas low enzyme activity was observed in M. gypseum isolates. Homology study of obtained nucleotide as well as amino acid sequences indicated different rates of homology with other subtilisin-like proteases genes in other pathogenic dermato­phytes."nConclusion: Intra-strain differences were observed in production of serine proteinases and molecular characterization of genes encoding such enzymes could be of great interest for studies on pathogenicity and other purposes. &nbsp

Published
2009

19. Synthesis of the fusarinin scaffold

Author

Bertrand, Samuel, Duval, Olivier, Larcher, Gérald, Richomme, Pascal, Substances d'Origine Naturelle et Analogues Structuraux (SONAS), Université d'Angers (UA), and Groupe d'Étude des Interactions Hôte-Pathogène (GEIHP)

Subjects
[SDV]Life Sciences [q-bio]
Abstract

Date du colloque: 09/2009

Published
2009

37. Siderophore Production by Pathogenic Mucorales and Uptake of Deferoxamine B.

Author

Larcher, Gérald, Dias, Marylène, Razafimandimby, Bienvenue, Bomal, Danielle, and Bouchara, Jean-Philippe

Abstract

Clinical reports have established that mucormycosis, mainly caused by Rhizopus spp., frequently occurs in patients treated with deferoxamine B (DFO, Desferal ®) which is misappropriated by these fungi. Siderophore production by twenty mucoralean isolates was therefore investigated using a commercial iron-depleted culture medium. Siderophore production was detected for most of the isolates. Our experiments confirmed that feroxamine B (iron chelate of DFO) promoted in vitro growth of Rhizopus arrhizus. Electrophoretic analysis of somatic extracts revealed iron-regulated proteins of 60 and 32 kDa which were lacking in iron-depleted culture conditions. Using a fluorescent derivative of deferoxamine B, we showed by fluorescence microscopy the entry of the siderophore within the fungal cells, thus suggesting a shuttle mechanism encompassing the uptake of the entire siderophore-ion complex into the cell. This useful tool renders possible a better understanding of iron metabolism in Mucorales which could lead to the development of new diagnostic method or new antifungal therapy using siderophores as imaging contrast agents or active drug vectors. [ABSTRACT FROM AUTHOR]

Published
2013
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43. Nα-methyl coprogen B, a potential marker of the airway colonization by Scedosporium apiospermum in patients with cystic fibrosis.

Author

Bertrand, Samuel, Bouchara, Jean-Philippe, Venier, Marie-Claire, Richomme, Pascal, Duval, Olivier, and Larcher, Gérald

Abstract

Scedosporium apiospermum is an emerging pathogen colonizing the airways of patients with cystic fibrosis (CF). While usually responsible for chronic colonization without clinical signs, this fungus may cause severe and often lethal infections in lung transplant recipients. Early diagnosis of its airway colonization and appropriate treatment are required to eradicate the fungus when a lung transplantation is planned. Here we propose an alternative to mycological examination of sputum samples based on extraction of siderophores by chromatography on Amberlite XAD-4, followed by high performance liquid chromatography analysis of the siderophore extract. Improvement of the extraction procedure was performed in a fractional factorial design which revealed the importance of prior ammonium sulfate precipitation of the proteins, alkalinization of the obtained solution and stirring during extraction. In order to verify the specificity of Nα-methyl coprogen B for S. apiospermum, the method was applied on culture supernatants of different filamentous fungi colonizing the airways of CF patients, including some aspergilli and Exophiala dermatitidis. Nα-methyl coprogen B was detected exclusively for species of the S. apiospermum complex. Likewise, sputum samples from colonized and non-colonized CF patients were analyzed, and the siderophore was detected exclusively in three out of the five specimens which were found by culture to contain S. apiospermum. Together these results confirmed Nα-methyl coprogen B as a marker of the airway colonization by species of the S. apiospermum complex. [ABSTRACT FROM AUTHOR]

Published
2010
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44. Synthesis of new 1-[2-Azido-2-(2,4-dichlorophenyl)ethyl]-1H/-imidazoles and in vitro evaluation of their antifungal activity.

Author

Chevreuil, Francis, Landreau, Anne, Seraphin, Denis, Larcher, Gérald, Bouchara, Jean-Philippe, and Richomme, Pascal

Subjects
IMIDAZOLES, ANTIFUNGAL agents, CANDIDA albicans, AZIDES, ASPERGILLUS fumigatus, AZOLES
Abstract

New 1-[2-azido-2-(2,4-dichlorophenyl)ethyl]-1H/-imidazole were synthesized by nucleophilic substitution of various tertiary alcohols with azide anion in presence of boron trifluoride-diethyl etherate. Their antifungal activity was evaluated against Candida albicans, Candida glabrata, Aspergillus fumigatus and an azole-resistant petite mutant of C. glabrata. Preliminary SAR results are discussed. [ABSTRACT FROM AUTHOR]

Published
2008
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46. A Nonsense Mutation in the ERG6Gene Leads to Reduced Susceptibility to Polyenes in a Clinical Isolate of Candida glabrata

Author

Vandeputte, Patrick, Tronchin, Guy, Larcher, Gérald, Ernoult, Emilie, Bergès, Thierry, Chabasse, Dominique, and Bouchara, Jean-Philippe

Abstract

ABSTRACTUnlike the molecular mechanisms that lead to azole drug resistance, the molecular mechanisms that lead to polyene resistance are poorly documented, especially in pathogenic yeasts. We investigated the molecular mechanisms responsible for the reduced susceptibility to polyenes of a clinical isolate of Candida glabrata. Sterol content was analyzed by gas-phase chromatography, and we determined the sequences and levels of expression of several genes involved in ergosterol biosynthesis. We also investigated the effects of the mutation harbored by this isolate on the morphology and ultrastructure of the cell, cell viability, and vitality and susceptibility to cell wall-perturbing agents. The isolate had a lower ergosterol content in its membranes than the wild type, and the lower ergosterol content was found to be associated with a nonsense mutation in the ERG6gene and induction of the ergosterol biosynthesis pathway. Modifications of the cell wall were also seen, accompanied by increased susceptibility to cell wall-perturbing agents. Finally, this mutation, which resulted in a marked fitness cost, was associated with a higher rate of cell mortality. Wild-type properties were restored by complementation of the isolate with a centromeric plasmid containing a wild-type copy of the ERG6gene. In conclusion, we have identified the molecular event responsible for decreased susceptibility to polyenes in a clinical isolate of C. glabrata. The nonsense mutation detected in the ERG6gene of this isolate led to a decrease in ergosterol content. This isolate may constitute a useful tool for analysis of the relevance of protein trafficking in the phenomena of azole resistance and pseudohyphal growth.

Published
2008
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48. Purification and characterization of a fibrinogenolytic serine proteinase from Aspergillus fumigatusculture filtrate

Author

Larcher, Gérald, Bouchara, Jean-Philippe, Annaix, Véronique, Symoens, Françoise, Chabasse, Dominique, and Tronchin, Guy

Abstract

A fibrinogenolytic proteinase has been isolated from Aspergillus fumigatusculture filtrate by ammonium sulfate precipitation followed by successive chromatographics on Sephadex G-75 and immobilized phenylalanine. The purified proteinase exhibited a molecular weight of about 33 kDa. When analysed by SDS-polyacrylamide gels containing co-polymerized fibrinogen, the proteinase appeared as a broad band at the top of the gels, which could correspond to polymerization of the enzyme, as suggested by SDS-PAGE analysis of the unboiled eluate. The isoelectric point was 8.75 and the enzyme was not glycosylated. Proteinase activity was optimum at pH 9 and between 37 and 42°C, although a decrease in activity was observed above 37°C. PMSF and chymostatin markedly inhibited the proteinase activity, and good kinetic constants were obtained for the synthetic substrate, N-Suc-Ala-Ala-Pro-Phe-pNA. These results provide direct evidence that this enzyme belongs to the chymotrypsin-like serine proteinase group.

Published
1992
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50. Spider bites in France: Epidaemiology of cases occurring in 10 years in metropolitan France.

Author

Le Roux G, Richard V, Larcher G, Sinno-Tellier S, Labadie M, de Haro L, and Descatha A

Subjects
Animals, France epidemiology, Phobic Disorders, Retrospective Studies, Spider Bites epidemiology, Spider Bites veterinary, Spiders
Abstract

Spiders are often wrongly designated as responsible for cutaneous eruptions. We aim to describe spider bites and the spider species implicated in metropolitan France. A retrospective observational study was conducted for all reported cases of spider bites from 2007 to 2018 extracted from the French Poison Control Centers (PCCs) information system, after exclusion of non-native spiders. We described identification of the spider, level of certainty of the bite, symptoms and severity of cases. 1194 cases of spider bites met the inclusion criteria. The average age of the patients was 36.9 ± 19.8 years. Identification of the species or at least that a spider was implicated was only possible in 346 cases (29.0%). Loxosceles were involved in 53 cases (4.4%), Latrodectus in 46 cases (3.9%) and Cheiracanthium in 35 cases (2.9%). In one third of cases, the involved spider was not known to be present where the bite occurred. Where most of the patients (n = 1111, 93%) reported at least one cutaneous symptom, most of the symptoms were neurological. The bite was considered proven in only 242 cases (20%). Despite the efforts of arachnologists to educate the public, the fear of spiders is still alive in France, where spider bite is rare with low severity and often unproven., (© 2021 Royal Entomological Society.)

Published
2022
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