Sebastien Bertout

Université de Montpellier | UM1 · Recherches translationnelles appliquées au VIH et aux Maladies Infectieuses - UMI 233

Neuromeningeal cryptococcosis is a life-threatening infection of the central nervous system, caused by encapsulated yeast belonging to the Cryptococcus neoformans and Cryptococcus gattii species complexes. Recent data showed that virulence and antifungal resistance are variable for yeasts belonging to the C. gattii species complex. There is an incr...

Background: Cross-resistance to medical azoles by exposure to azole pesticides is well documented for Aspergillus family fungi but is poorly evaluated for other environmental pathogen fungi, particularly for yeasts belonging to the Cryptococcus neoformans/Cryptococcus gattii species complexes. Methods: One thousand C. neoformans yeast were expos...

S8.5 Genotyping of Cryptococcus neoformans and C. gattii, September 23, 2022, 3:00 PM - 4:30 PM Objectives In a previous study a set of new molecular-type specific primers were designed to apply the standard ISHAM consensus multi-locus sequence typing (MLST) scheme to Cryptococcus neoformans AD hybrids. In the present study, we report the prelimin...

Aims: This study was conducted to determine the respective prevalence of Candida species and to study their sensitivity profile to antifungal agents to identify the emergence of resistance. Methods: This retrospective study was conducted from 2017 to 2019 at the Institute Pasteur of Côte d’Ivoire on patients with fungal disease. Various samples wer...

Fungi belonging to the Cryptococcus genus and related genera (Filobasidium, Holtermanniella, Naganishia, Papiliotrema, Solicoccozyma, Vishniacozyma) are encapsulated yeasts found in either the environment or animal sources. However, the precise biotopes of most species remain poorly defined. To assess whether wild birds from southern France can car...

Background Cryptococcus neoformans and Cryptococcus gattii species complexes are pathogens causing cryptococcal meningitis, a fungal infection that leads to death unless treated. Worldwide, it is estimated to kill over 180,000 individuals annually. Objectives We aim to investigate the molecular diversity of C. gattii isolates from strains isolated...

Introduction L’ivermectine est connue pour provoquer des encéphalopathies sévères chez les sujets infectés par Loa loa, parasite endémique en Afrique centrale. De plus, des études de cas ont rapporté d’autres effets indésirables graves liés à l’ivermectine, tels que des toxidermies ou des atteintes hépatiques ou rénales. L’objectif de cette étude é...

Background Ivermectin is known to cause severe encephalopathies in subjects infected with loiasis, an endemic parasite in Sub-Saharan Africa (SSA). In addition, case reports have described ivermectin-related serious adverse drug reactions (sADRs) such as toxidermias, hepatic and renal disorders. The aim of this study was to identify suspected sADRs...

Introduction: Cryptococcus gattii species complex is endemic to tropical and subtropical regions and is described as a causative agent of cryptococcosis in immunocompetent individuals. Case presentation: We describe the first case of cryptococcosis in a HIV-negative patient from Ivory Coast infected by Cryptococcus gattii sensu stricto VGI. Isolate...

: Although AD hybrids within the Cryptococcus neoformans species complex represent about 20% of the isolates identified in Europe, phylogenetic and population genetic studies are lacking due to the inability to use the standardized typing method. The aim of the present study was to design new molecular type specific primers in order to apply the s...

Genetic diversity analyses were performed by sero-genotyping and multi-locus sequence typing on 252 cryptococcal isolates from 13 HIV-positive Ivorian patients followed-up for cryptococcal meningitis. Antifungal susceptibility analyses were performed according to the CLSI M27A3 method. The majority (67.8%) of the isolates belonged to the Cryptococc...

ABSTRACT Objectives Fluconazole, alone or in association, is often administered during cryptococcal meningitis treatment, especially in sub-Saharan Africa. Its extensive use has led to the emergence of resistant strains. The mechanisms underlying resistance are poorly documented for yeasts belonging to the Cryptococcus gattii species complex. The...

Non-albicans Candida (NAC) species have emerged as potent pathogenic yeasts among HIV-infected patients. Authors evaluated the epidemiology and antifungal susceptibility testing of non-albicans Candida species colonizing Yaounde´ (capital of the Republic of Cameroon, Central Africa) HIV-infected patients. The mucosal specimens were collected and su...

Purpose: The aim of this study was to assess the biotope of the Cryptococcus neoformans/Cryptococcus gattii species complex from Ivory Coast, and clarify the possible epidemiological relationship between environmental and clinical strains. Methodology: Samples from Eucalyptus camaldulensis (n=136), Mangifera indica (n=13) and pigeon droppings (n...

Fundamental niche prediction of Cryptococcus neoformans and C. gattii in Europe is an important tool to understand where these yeasts have a high probability to survive in the environment and therefore to identify the areas with high risk of infection. In the present study occurrence data for C. neoformans and C. gattii were compared by MaxEnt soft...

Cryptococcosis is a major fungal disease caused by members of the Cryptococcus gattii and Cryptococcus neoformans species complexes. After more than 15 years of molecular genetic and phenotypic studies and much debate, a proposal for a taxonomic revision was made. The two varieties within C. neoformans were raised to species level, and the same was...

The molecular epidemiology and the antifungal susceptibility profiles of Candida albicans are scarce in Cameroon. Authors studied the genetic diversity and the antifungal susceptibility of C. albicans isolates from Yaoundé HIV-infected patients. Clinical isolates were obtained by mycological diagnosis of oropharyngeal swabs, stools, urine, and vagi...

Cryptococcal meningitis is a severe opportunistic infection in HIV-infected patients. In Ivory Coast, despite the availability of antiretroviral treatment (ART), this infection is still prevalent. The study investigates the genetic diversity of 363 clinical isolates of Cryptococcus from 61 Ivorian HIV-positive patients, the occurrence of mixed infe...

In order to elucidate the distribution of Cryptococcus neoformans and C. gattii in the Mediterranean basin, an extensive environmental survey was carried out during 2012–15. A total of 302 sites located in 12 countries were sampled, 6436 samples from 3765 trees were collected, and 5% of trees were found to be colonized by cryptococcal yeasts. Crypt...

In order to elucidate the distribution of Cryptococcus neoformans and C. gattii in the Mediterranean basin, an extensive environmental survey was carried out during 2012-2015. A total of 302 sites located in 12 countries were sampled, 6436 samples from 3765 trees were collected and 5% of trees were found to be colonized by cryptococcal yeasts. Cryp...

Cryptococcal meningitis is a dreadful opportunistic fungal infection amongst HIV-infected patients. One complication in the management of the disease is the probable infection of a patient by 2 or more different strains of Cryptococcus neoformans. This study investigated the intra individual genetic diversity and the antifungal susceptibility of C....

Introduction Cryptococcal meningitis (CM) may be caused by several species of Cryptococcus. Case presentation We describe a fatal case of CM in a HIV-positive patient from Ivory Coast infected by Cryptococcus neoformans VNI and Cryptococcus deuterogattii. Isolates were recovered from cerebrospinal fluid (CSF) prior to systemic antifungal treatment...

Mycoses caused by Candida and Cryptococcus species, associated with the advent of antifungal drug resistance have emerged as major health problems. Improved control measures and innovative therapies are needed. This paper describes results from the screening of bio-guided fractionated extracts alone and combinations of Terminalia catappa, Terminali...

Cryptococcal meningitis is a mycosis encountered especially in patients with Acquired Immunodeficiency Syndrome and is fatal in the absence of treatment. Information on epidemiology, diagnosis and susceptibility profile to antifungal drugs, are scarce in Cameroon. Authors evaluated the diagnosis possibilities of the cryptococcal meningitis in Camer...

Minor species of the Candida albicans complex may cause overestimation of the epidemiology of C. albicans, and misidentifications could mask their implication in human pathology. Authors determined the occurrence of minor species of the C. albicans complex (C. africana, C. dubliniensis and C. stellatoidea) among Yaoundé HIV-infected patients, Camer...

We tested 114 faecal samples from wild simian immunodeficiency virus (SIV)-positive (n = 43) and SIV-negative (n = 71) chimpanzees (Pan troglodytes troglodytes) in southeast Cameroon for the presence of gastrointestinal parasites by direct smear. We observed cysts from different protozoa (Entamoeba coli and Entamoeba histolytica / Entamoeba dispar,...

Candida glabrata has emerged as a major pathogen in invasive candidiasis in recent years. Currently, guidelines for invasive candidiasis treatment recommend fluconazole or an echinocandin as the first-line therapy. Nevertheless, the resistance of Candida glabrata to echinocandin is an emerging problem and has been partly associated with mutations i...

In recent years, Geosmithia argillacea has been increasingly reported in humans and animals and can be considered an emerging pathogen. The taxonomy of Geosmithia was recently studied, and Geosmithia argillacea and related species were transferred to the new genus Rasamsonia. The diversity among a set of Rasamsonia argillacea strains, including 28...

Cystic fibrosis (CF) patients are at high risk of colonization of the airways by a number of fungi, including the emerging opportunistic fungus Geosmithia argillacea. We report the eradication of respiratory G. argillacea associated with clinical resolution of severe symptoms by high-dose and prolonged micafungin therapy in a young CF patient.

Clin Microbiol Infect ABSTRACT: Cryptococcus neoformans is the most common cause of meningitis amongst adult Africans with HIV/AIDS. The widespread use of fluconazole may lead to the emergence of isolates with reduced susceptibility. We studied C. neoformans isolates from HIV-infected patients with cryptococcal meningitis. Genotyping and antifungal...

This study aimed to assess the interlaboratory reproducibility at four university hospital laboratories in the southeast region of France of the Etest technique for the determination of caspofungin (CAS) and amphotericin B (AMB) MICs and to compare it to the CLSI broth microdilution reference method. Consecutive clinical yeast isolates (n = 198) we...

Caspofungin is a member of the echinocandin class of antifungal compounds that inhibit 1,3-β-d-Glucan synthase. As patient exposure to caspofungin (CAS) broadens, the number of infecting strains with reduced susceptibility to this drug is expected to rise. In the present study, the in vitro effects of varying concentrations of CAS against Candida a...

Brain or renal Aspergillus abscesses are very rare complications of HIV infection. Invasive aspergillosis is found in patients with severe immune deficiency. In AIDS patients, it is usually associated with neutropenia. We present a case of a 45-year-old man, a former intravenous drug user, who first developed pulmonary disseminated aspergillosis tr...

The Clinical Laboratory Standards Institute ([CLSI] formerly NCCLS) reference broth microdilution testing method (protocol M27-A3) was compared with a commercially available methods (Sensititre YeastOne(®)) by testing two quality control strains and 102 isolates of Candida sp. and Cryptococcus sp. against fluconazole, itraconazole, ketoconazole, po...

We studied the cell wall of a Candida albicans laboratory mutant exhibiting a high minimum inhibitory concentration (MIC; 8 µg ml−1) for caspofungin without bearing FKS1 mutations. This strain showed a reduced level of ß 1,3 D glucan (0.43×) and a higher chitin content (2.3×) than a control strain even when grown without caspofungin. No significant...

Infections due to Candida spp. are frequent, particularly in immunocompromised and intensive care unit patients. Antifungal susceptibility tests are now required to optimize antifungal treatment given the emergence of acquired antifungal resistance in some Candida species. An antifungal susceptibility automated method, the Vitek 2 system (VK2), was...

The purpose of our study was to provide data to medical biologists for the choice of a routine technique for antifungal MIC testing of Candida sp. strains. In vitro susceptibility to amphotericin B, 5-fluorocytosine, fluconazole, itraconazole, voriconazole and caspofungin were determined for 46 Candida isolates coming from a French multicentric epi...

Background: Echinocandins antifungal drugs target the fungal cell wall. Resistance of clinical Candida albicans isolates to caspofungin (CAS) is emerging and is often linked to mutations in the FKS1 gene. However, additional studies are required to better understand of resistance mechanism. CRH11 is a gene involved in the cell wall regeneration and...

The aim of this work was to develop LightCycler real-time polymerase chain reaction method to allow rapid detection and identification of Candida spp. in human serum with panfungal primers (internal transcribed spacer [ITS] and L18). Melting-curve analysis of the ITS sequences showed that each amplicon presented a specific melting point and enabled...

Caspofungine belongs to the echinocandin family. It is a large lipopeptide molecule that inihibits the β-(1,3)-glucan synthesis, a cell wall component. No drug target is present in mammalian cells. In vitro data and experimental studies have demonstrated that caspofungin displays antifungal activity against most Candida spp. (including isolates res...

We have investigated the genotype at 14 enzyme-encoding loci in 275 isolates of the pathogenic yeast Candida albicans sampled from 42 HIV-positive patients (all but one with AIDS) from Abidjan (Côte d’Ivoire). We separately analyzed the following variables: patient, residence, age, gender, T cell count, hospitalization (yes or no), drug treatment,...

Hyalohyphomycosis are worldwide opportunistic infections caused by non-Aspergillus hyaline moulds originating from soil. Currently 24 genera and about 50 species are involved in human mycosis. The most important hyalohyphomycetes belong to Acremonium, Beauveria, Chrysosporium, Fusarium, Onychocola, Paecilomyces, Penicillium, Scedosporium and Scopul...

It seems that S. cerevisiae, which was thought for about 30 years to be a nonpathogenic yeast, should now be considered an opportunistic pathogen. In this study, we estimated the discrimination ability of the microsatellite sequence amplification technique within a sample of clinical and reference S. cerevisiae strains and S. boulardii reference st...

Candida arteritis can compromise the functional prognosis of the graft or even the life of the transplant recipient. The infection can be transmitted by the graft. A 46 year-old woman contracted a Candida albicans ateritis of the graft following a kidney transplant that led to a detransplantation. The yeast was probably transmitted by the graft fro...

Une artérite candidosique peut mettre en jeu le pronostic fonctionnel du greffon voire la vie du receveur. L’agent infectieux peut être transmis par le greffon.

Introduction Candida arteritis can compromise the functional prognosis of the graft or even the life of the transplant recipient. The infection can be transmitted by the graft. Observation A 46 year-old woman contracted a Candida albicans ateritis of the graft following a kidney transplant that led to a de-transplantation. The yeast was probably t...

The incidence of invasive fungal infections had risen dramatically during the past 2 decades. This phenomenon was due to recent advances in medical and surgical therapies (i.e. intensive anticancer therapy, aggressive surgical interventions, organ and bone marrow transplantations). Molecular typing methods are useful tools in molecular mycology. Th...

Background. Antifungal combinations are more frequently used for the treatment of systemic mycoses patients and considering the increased resistance of many fungi. The aim of this study was to evaluate by the Etest method the in vitro antifungal activity of different combinations of antifungal drugs against various species of Candida. Material and...

Aspergillus fumigatus is a ubiquitous fungus that grows in decaying organic matter. It can cause disease in both immunodeficient and immunocompetent patients by using virulence factors to escape the host defenses. Some of these factors, such as a diffusate, released from the spores of A. fumigatus, have previously been described. This diffusate was...

Multilocus enzyme electrophoresis was performed on 76 European strains of Candida dubliniensis. Ten of the 20 enzyme-encoding loci were polymorphic, giving rise to 10 electrophoretic types within the sample studied. Investigation of the population genetics of a subset of 36 strains from HIV-infected patients in London showed the existence of strong...

Aspergillus infection is a well-known complication of lung transplantation and remains associated with high mortality rates. Molecular typing methods are required to elucidate the complex epidemiology of Aspergillus disease in lung transplant recipients. Eight lung transplant recipients from one hospital were followed for A fumigatus colonization o...

The genotypes of 52 strains of Aspergillus fumigatus isolated from 12 patients with invasive aspergillosis were investigated using three typing methods (random amplified polymorphic DNA, sequence-specific DNA polymorphism, and microsatellite polymorphism) combined with multilocus enzyme electrophoresis. Isolates were from patients hospitalized in t...

Candida dubliniensis is a novel species only recently described. This emerging pathogen shares some of the phenotypic characteristics specific to C. albicans but is genetically different. In this study we typed four strains of atypical C. albicans isolated in our laboratory and compared them to 41 strains of C. albicans and 11 strains of C. dublini...

The yeast Saccharomyces boulardii is widely used for clinical purposes. A major use is in treatment and the prevention of diarrhea, particularly diarrhea resulting from treatment with antibiotics. A range of phenotypic features have led to its inclusion in the Saccharomyces sensu stricto complex, which contains S. cerevisiae, S. bayanus, S. paradox...

Candida dubliniensis is a novel species only recently described. This emerging pathogen shares some of the phenotypic characteristics specific to C. albicans but is genetically different. In this study we typed four strains of atypical C. albicans isolated in our laboratory and compared them to 41 strains of C. albicans and 11 strains of C. dublini...

The genotypes of 50 isolates of Aspergillus fumigatus from 11 patients with invasive aspergillosis, obtained from three hospitals in different geographical areas, were determined by multilocus enzyme electrophoresis (MLEE). The study analysed the genetic polymorphism of multiple isolates from the first sample. Seven of the 14 enzymic loci studied w...

The genotypes of 50 isolates of Aspergillus fumigatus from 11 patients with invasive aspergillosis, obtained from three hospitals in different geographical areas, were determined by multilocus enzyme electrophoresis (MLEE), The study analysed the genetic polymorphism of multiple isolates from the first sample, Seven of the 14 enzymic loci studied w...

Objective. The aim of the study was to analyze the influence of different parameters of in vitro antifungal susceptibility testing of Aspergillus fumigatus strains on the inter- and intra-laboratory reproducibility and on the ability to detect itraconazole resistance. Methods. Amphotericin B and itraconazole testings were performed in parallel by t...

The genotypes of 107 strains of Cryptococcus isolated from the environment or from patients from various geographical areas were determined by multilocus enzyme electrophoresis (MLEE). We analyzed the relationships between genotype structure and serotype and between genotype structure and strain origin. Twelve of the 14 enzyme-encoding loci studied...