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1.
Mycoses ; 65(1): 88-96, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34726802

RESUMEN

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 from 1995 to the present day from different continents. METHOD: In this study, we analysed the molecular diversity by MLST and antifungal susceptibility by using the broth microdilution method according to the CLSI M27-A4 protocol of a total of 26 strains from Cryptococcus gattii species complex from both clinical and environmental sources. RESULTS: Genotyping showed that most of the strains (17/26; 65.4%) belonged to serotype B and were distributed between three genotypes: VGI (13/17; 76.5%), VGII (3/17; 17.6%) and VGVI (1/17; 5.9%). The serotype C strains (9/26; 34.6%) were distributed between the VGIII (1/9; 11.1%) and VGIV (8/9; 88.9%) genotypes. The 26 strains belonged to 17 different MLST subtypes, and we highlight four new MLST genotypes (ST553, 554, 555 and 556). The two environmental strains were identified as serotype B and genotype VGI, but were of ST 51 and 154. All isolates have wild-type MIC of fluconazole and flucytosine. Regarding amphotericin B, five VGI strains showed MICs to AMB equal to 1 µg/ml, and according to the ECV for these genotypes, they were considered non-wild-type strains. CONCLUSIONS: The current study reveals the genetic diversity and new sequence types among strains from the C. gattii complex species.


Asunto(s)
Criptococosis , Cryptococcus gattii , Criptococosis/epidemiología , Criptococosis/microbiología , Cryptococcus gattii/clasificación , Cryptococcus gattii/genética , Fluconazol/farmacología , Flucitosina/farmacología , Genotipo , Humanos , Tipificación de Secuencias Multilocus , Técnicas de Tipificación Micológica
2.
Med Mycol ; 58(7): 1005-1009, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-32511709

RESUMEN

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 standard ISHAM consensus multilocus sequence typing (MLST) scheme to AD hybrids. The new primers are able to specifically amplify VNI and VNIV alleles of the seven MLST loci in both haploid and diploid or aneuploid hybrid strains. This study forms the basis for future molecular epidemiology studies of AD hybrids. LAY ABSTRACT: We designed and tested new specific primers to amplify the two alleles of each of the seven MLST loci in C. neoformans species complex hybrids. The sequences obtained from hybrids can be compared with those present in the Cryptococcus global MLST database for future molecular epidemiology studies.


Asunto(s)
Quimera/genética , Cryptococcus neoformans/clasificación , Cryptococcus neoformans/genética , Técnicas de Genotipaje , Tipificación de Secuencias Multilocus/métodos , Técnicas de Tipificación Micológica , Europa (Continente) , Variación Genética , Genotipo , Humanos , Filogenia
3.
Fungal Genet Biol ; 129: 16-29, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30953839

RESUMEN

A total of 476 European isolates (310 Cryptococcus neoformans var. grubii, 150 C. neoformans var. neoformans, and 16 C. gattii species complex) from both clinical and environmental sources were analyzed by multi-locus sequence typing. Phylogenetic and population genetic analyses were performed. Sequence analysis identified 74 sequence types among C. neoformans var. neoformans (VNIV), 65 among C. neoformans var. grubii (56 VNI, 8 VNII, 1 VNB), and 5 among the C. gattii species complex (4 VGI and 1 VGIV) isolates. ST23 was the most frequent genotype (22%) among VNI isolates which were mostly grouped in a large clonal cluster including 50% of isolates. Among VNIV isolates, a predominant genotype was not identified. A high percentage of autochthonous STs were identified in both VNI (71%) and VNIV (96%) group of isolates. The 16 European C. gattii species complex isolates analyzed in the present study originated all from the environment and all belonged to a large cluster endemic in the Mediterranean area. Population genetic analysis confirmed that VNI group of isolates were characterized by low variability and clonal expansion while VNIV by a higher variability and a number of recombination events. However, when VNI and VNIV environmental isolates were compared, they showed a similar population structure with a high percentage of shared mutations and the absence of fixed mutations. Also linkage disequilibrium analysis reveals differences between clinical and environmental isolates showing a key role of PLB1 allele combinations in host infection as well as the key role of LAC1 allele combinations for survival of the fungus in the environment. The present study shows that genetic comparison of clinical and environmental isolates represents a first step to understand the genetic characteristics that cause the shift of some genotypes from a saprophytic to a parasitic life style.


Asunto(s)
Cryptococcus gattii/genética , Cryptococcus neoformans/genética , Genotipo , Filogenia , Animales , Microbiología Ambiental , Europa (Continente) , Genética de Población , Humanos , Región Mediterránea , Tipificación de Secuencias Multilocus , Técnicas de Tipificación Micológica
4.
Environ Microbiol ; 19(10): 4318-4325, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28892309

RESUMEN

Fundamental niche prediction of Cryptococcus neoformans and Cryptococcus gattii in Europe is an important tool to understand where these pathogenic yeasts have a high probability to survive in the environment and therefore to identify the areas with high risk of infection. In this study, occurrence data for C. neoformans and C. gattii were compared by MaxEnt software with several bioclimatic conditions as well as with soil characteristics and land use. The results showed that C. gattii distribution can be predicted with high probability along the Mediterranean coast. The analysis of variables showed that its distribution is limited by low temperatures during the coldest season, and by heavy precipitations in the driest season. C. neoformans var. grubii is able to colonize the same areas of C. gattii but is more tolerant to cold winter temperatures and summer precipitations. In contrast, the C. neoformans var. neoformans map was completely different. The best conditions for its survival were displayed in sub-continental areas and not along the Mediterranean coasts. In conclusion, we produced for the first time detailed prediction maps of the species and varieties of the C. neoformans and C. gattii species complex in Europe and Mediterranean area.


Asunto(s)
Microambiente Celular/fisiología , Cryptococcus gattii/crecimiento & desarrollo , Cryptococcus neoformans/crecimiento & desarrollo , Microbiología Ambiental , Microbiología del Suelo , Criptococosis/microbiología , Cryptococcus gattii/metabolismo , Cryptococcus neoformans/metabolismo , Europa (Continente) , Región Mediterránea , Estaciones del Año , Suelo/química , Tiempo (Meteorología)
5.
Med Mycol ; 55(5): 546-554, 2017 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-27744307

RESUMEN

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 vaginal swabs from patients. C. albicans isolates were confirmed by the Light cycler real-time PCR of the ITS1 region of the 5.8s ribosomal DNA. The ABC genotypes and the Hwp1 gene amplification were carried out with specific primers. Microsatellite length polymorphism of HIS3, CDC3, and EF3 microsatellites was analysed. The antifungal susceptibility testing was carried out by the CLSI broth microdilution M27-A3 and M27-S4 protocols. The minimal inhibitory concentration (MIC) results were interpreted according to updated clinical breakpoints (CBPs) recommended by the CLSI or epidemiological cut-off values (ECVs). One hundred and thirteen (113) isolates were obtained from the analysis of 1218 samples. The ABC genotyping showed 79 (69.91%) genotype A, 24 (21.23%) genotype B, and 10 (8.84%) genotype C. The Hwp1 gene amplification provided a newly observed genetic polymorphism, named H and 5 genotypes described (H1-H5). The microsatellite analysis generated 65 molecular types. All the isolates were susceptible to amphotericin B (MIC ≤ 1 µg/ml); 79.64% of isolates were wild type to itraconazole (MIC ≤ 0.12 µg/ml); and 86.72% of isolates were susceptible to fluconazole (MIC ≤ 2 µg/ml). These results highlight the important genetic diversity of C. albicans isolates among Yaoundé HIV-infected patients and bring clues for the comprehension of the molecular epidemiology of the yeast in Cameroon.


Asunto(s)
Antifúngicos/farmacología , Candida albicans/efectos de los fármacos , Candida albicans/genética , Genes Fúngicos/genética , Variación Genética , Infecciones por VIH/complicaciones , Repeticiones de Microsatélite/genética , Camerún , Candida albicans/clasificación , Candida albicans/aislamiento & purificación , Farmacorresistencia Fúngica , Proteínas Fúngicas/genética , Genotipo , Humanos , Glicoproteínas de Membrana/genética , Pruebas de Sensibilidad Microbiana , Epidemiología Molecular , Tipificación Molecular , Reacción en Cadena en Tiempo Real de la Polimerasa
6.
FEMS Yeast Res ; 16(4)2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27188887

RESUMEN

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. Cryptococcus neoformans was isolated from 177 trees and C. gattii from 13. Cryptococcus neoformans colonized 27% of Ceratonia, 10% of Olea, Platanus and Prunus trees and a lower percentage of other tree genera. The 13 C. gattii isolates were collected from five Eucalyptus, four Ceratonia, two Pinus and two Olea trees. Cryptococcus neoformans was distributed all around the Mediterranean basin, whereas C. gattii was isolated in Greece, Southern Italy and Spain, in agreement with previous findings from both clinical and environmental sources. Among C. neoformans isolates, VNI was the prevalent molecular type but VNII, VNIV and VNIII hybrid strains were also isolated. With the exception of a single VGIV isolate, all C. gattii isolates were VGI. The results confirmed the presence of both Cryptococcus species in the Mediterranean environment, and showed that both carob and olive trees represent an important niche for these yeasts.


Asunto(s)
Cryptococcus gattii/aislamiento & purificación , Cryptococcus neoformans/aislamiento & purificación , Microbiología Ambiental , Árboles/microbiología , Cryptococcus gattii/clasificación , Cryptococcus gattii/genética , Cryptococcus neoformans/clasificación , Cryptococcus neoformans/genética , Genotipo , Región Mediterránea , Tipificación Molecular , Técnicas de Tipificación Micológica
7.
Mycoses ; 59(12): 811-817, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27461533

RESUMEN

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 infections and the in vitro antifungal susceptibility of the isolates. Serotyping was performed via LAC1 and CAP64 gene amplification. Genotyping was performed using the phage M13 core (GACA)4 and (GTG)5 primers and restriction fragment length polymorphism analysis of the URA5 gene. By PCR fingerprinting, the presence of the three serotypes were demonstrated among the 363 isolates in the population studied: A (n=318; 87.6%), AD (n=40; 11%) and B (n=4; 1.1%). Using PCR fingerprinting with primers M13 (GACA)4 and (GTG)5 , we grouped the isolates into 56 molecular subtypes. We observed a high frequency (39.3%) of mixed infections, with up to two different genotypes per sample. None of the isolates were resistant to amphotericin B. Only 0.3% and 1.1% of the isolates were resistant to fluconazole and flucytosine respectively. This study revealed the high genetic diversity among Cryptococcus isolates, the occurrence of mixed infections and a high antifungal susceptibility for the majority of Ivorian cryptococcal isolates.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/microbiología , Criptococosis/microbiología , Cryptococcus gattii/genética , Cryptococcus neoformans/genética , Meningitis Criptocócica/microbiología , Infecciones Oportunistas Relacionadas con el SIDA/tratamiento farmacológico , Infecciones Oportunistas Relacionadas con el SIDA/epidemiología , Adulto , Anfotericina B/administración & dosificación , Antifúngicos/administración & dosificación , Côte d'Ivoire/epidemiología , Criptococosis/tratamiento farmacológico , Criptococosis/epidemiología , Cryptococcus gattii/clasificación , Cryptococcus gattii/efectos de los fármacos , Cryptococcus gattii/aislamiento & purificación , Cryptococcus neoformans/clasificación , Cryptococcus neoformans/efectos de los fármacos , Cryptococcus neoformans/aislamiento & purificación , Femenino , Variación Genética , Humanos , Masculino , Meningitis Criptocócica/tratamiento farmacológico , Meningitis Criptocócica/epidemiología , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Epidemiología Molecular , Técnicas de Tipificación Micológica , Polimorfismo de Longitud del Fragmento de Restricción , Estudios Prospectivos , Adulto Joven
8.
Mycoses ; 58(1): 33-9, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25289589

RESUMEN

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, Cameroon. Stool, vaginal discharge, urine and oropharyngeal samples were analysed by mycological diagnosis. Isolates were identified by conventional methods and mass spectrometry (MS; carried out by the matrix-assisted laser desorption-ionisation time-of-flight MS protocol). Candida albicans isolates were thereafter submitted to the PCR amplification of the Hwp1 gene. The susceptibility of isolates to antifungal drugs was tested using the Clinical and Laboratory Standards Institute M27-A3 protocol. From 115 C. albicans obtained isolates, neither C. dubliniensis nor C. stellatoidea was observed; two strains of C. africana (422PV and 448PV) were identified by PCR electrophoretic profiles at 700 bp. These two C. africana strains were vaginal isolates. The isolate 448PV was resistant to ketoconazole at the minimal inhibitory concentration of 2 µg ml(-1), and showed reduced susceptibility to amphotericin B at 1 µg ml(-1). This first report on C. africana occurrence in Cameroon brings clues for the understanding of the global epidemiology of this yeast as well as that of minor species of the C. albicans complex.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/microbiología , Candida/aislamiento & purificación , Candidiasis/diagnóstico , Candidiasis/microbiología , Vagina/microbiología , Infecciones Oportunistas Relacionadas con el SIDA/diagnóstico , Infecciones Oportunistas Relacionadas con el SIDA/epidemiología , Adolescente , Adulto , Anciano , Anfotericina B/farmacología , Antifúngicos/farmacología , Camerún/epidemiología , Candida/clasificación , Candida/efectos de los fármacos , Candida/fisiología , Candida albicans/clasificación , Candida albicans/aislamiento & purificación , Candidiasis/epidemiología , Farmacorresistencia Fúngica , Femenino , Regulación Fúngica de la Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Orina/microbiología , Adulto Joven
9.
Parasitol Res ; 113(7): 2541-50, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24781023

RESUMEN

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, Endolimax nana, Iodamoeba butschlii, Chilomastix mesnili, Balantidium coli and Blastocystis cells) and trophozoites from Troglodytella abrassarti and Balantidium coli. Eggs from different helminths (strongylids, Ascaris lumbricoides, Abbreviata caucasica, Trichuris sp., Capillaria sp., Enterobius anthropopeci, Bertiella sp., Hymenolepis diminuta and an undetermined fluke) were also observed. Finally, we observed eggs that could not be properly identified and classified. We did not observe any differences between the SIV+ and SIV- samples except for the unidentified eggs. The studied chimpanzees were highly parasitised by strongylid (85.1% of prevalence), Troglodytella (43.8%) and Blastocystis (2.9%), and the frequency of the other parasites ranged from 0.9 to 8.8%. These high levels of parasite infections could represent an additional burden in a population where there is a high rate of the SIV virus in circulation.


Asunto(s)
Entamoeba/clasificación , Entamebiasis/veterinaria , Helmintiasis Animal/epidemiología , Helmintos/clasificación , Parasitosis Intestinales/veterinaria , Pan troglodytes/parasitología , Animales , Camerún/epidemiología , Coinfección , Entamoeba/aislamiento & purificación , Entamebiasis/epidemiología , Entamebiasis/parasitología , Heces/parasitología , Helmintiasis Animal/parasitología , Helmintos/aislamiento & purificación , Parasitosis Intestinales/epidemiología , Parasitosis Intestinales/parasitología , Pan troglodytes/virología , Prevalencia , Síndrome de Inmunodeficiencia Adquirida del Simio/epidemiología , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/aislamiento & purificación
10.
Microbiol Spectr ; 12(2): e0144023, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38171008

RESUMEN

Malaria remains a global health problem, with 247 million cases and 619,000 deaths in 2021. Diagnosis of Plasmodium species is important for administering the appropriate treatment. The gold-standard diagnosis for accurate species identification remains the thin blood smear. Nevertheless, this method is time-consuming and requires highly skilled and trained microscopists. To overcome these issues, new diagnostic tools based on deep learning are emerging. This study aimed to evaluate the performances of a real-time detection transformer (RT-DETR) object detection algorithm to discriminate Plasmodium species on thin blood smear images. The algorithm was trained and validated on a data set consisting in 24,720 images from 475 thin blood smears corresponding to 2,002,597 labels. Performances were calculated with a test data set of 4,508 images from 170 smears corresponding to 358,825 labels coming from six French university hospitals. At the patient level, the RT-DETR algorithm exhibited an overall accuracy of 79.4% (135/170) with a recall of 74% (40/54) and 81.9% (95/116) for negative and positive smears, respectively. Among Plasmodium-positive smears, the global accuracy was 82.7% (91/110) with a recall of 90% (38/42), 81.8% (18/22), and 76.1% (35/46) for P. falciparum, P. malariae, and P. ovale/vivax, respectively. The RT-DETR model achieved a World Health Organization (WHO) competence level 2 for species identification. Besides, the RT-DETR algorithm may be run in real-time on low-cost devices such as a smartphone and could be suitable for deployment in low-resource setting areas lacking microscopy experts.IMPORTANCEMalaria remains a global health problem, with 247 million cases and 619,000 deaths in 2021. Diagnosis of Plasmodium species is important for administering the appropriate treatment. The gold-standard diagnosis for accurate species identification remains the thin blood smear. Nevertheless, this method is time-consuming and requires highly skilled and trained microscopists. To overcome these issues, new diagnostic tools based on deep learning are emerging. This study aimed to evaluate the performances of a real-time detection transformer (RT-DETR) object detection algorithm to discriminate Plasmodium species on thin blood smear images. Performances were calculated with a test data set of 4,508 images from 170 smears coming from six French university hospitals. The RT-DETR model achieved a World Health Organization (WHO) competence level 2 for species identification. Besides, the RT-DETR algorithm may be run in real-time on low-cost devices and could be suitable for deployment in low-resource setting areas.


Asunto(s)
Malaria Falciparum , Malaria , Piperazinas , Plasmodium , Humanos , Algoritmos , Plasmodium falciparum
11.
Bioorg Med Chem Lett ; 23(6): 1803-7, 2013 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-23403080

RESUMEN

Eighteen new hydrazino-1,3-thiazole derivatives were evaluated against 8 strains of multi-resistant Candida spp. Introduction of an indolyl moiety linked to the hydrazone function enhanced the in vitro anti-Candida activity, with an activity spectrum towards Candida albicans strains. Introduction of a (S)-2-aminoethyl chain on the thiazole nucleus largely enhanced the in vitro antifungal activity, with a selectivity oriented towards non-C. albicans species.


Asunto(s)
Antifúngicos/síntesis química , Tiazoles/química , Animales , Antifúngicos/farmacología , Antifúngicos/toxicidad , Candida/efectos de los fármacos , Candida albicans/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Farmacorresistencia Fúngica/efectos de los fármacos , Ratones , Pruebas de Sensibilidad Microbiana , Células 3T3 NIH , Relación Estructura-Actividad , Tiazoles/farmacología , Tiazoles/toxicidad
12.
Pathogens ; 12(6)2023 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-37375448

RESUMEN

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 increase in resistance to fluconazole for yeasts of the C. gattii species complex and the virulence is variable according to the genotype. In the present study, (i) we explored and compared the mechanisms of resistance to fluconazole between C. deuterogattii clinically resistant strains and induced fluconazole-resistant strains by exposure to fluconazole in vitro, and (ii) we studied their virulence in the Galleria mellonella study model. We demonstrated that the fluconazole resistance mechanisms involved were different between clinically resistant strains and induced resistant strains. We also demonstrated that fluconazole-induced resistant strains are less virulent when compared to the original susceptible strains. On the contrary, the clinically resistant strain tested maintains its virulence compared to fluconazole-susceptible strains of the same sequence type.

13.
Pathogens ; 12(5)2023 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-37242332

RESUMEN

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 exposed to various concentrations of seven different commonly used azole pesticides. Clones surviving exposure were picked randomly, and their minimal inhibitory concentrations (MICs) of fluconazole, voriconazole, posaconazole, itraconazole and isavuconazole were assessed. RESULTS: Depending on the pesticide used for exposure, up to 13.3% of selected Cryptococcus colonies showed a phenotype of resistance to fluconazole, and among them, several showed cross-resistance to another or several other medical azoles. Molecular mechanisms involved in the resistance setups seem to be dependent on ERG11 and AFR1 gene overexpression. CONCLUSION: Exposure to any of the seven azole pesticides tested is capable of increasing the MIC of fluconazole in C. neoformans, including up to the level of the fluconazole-resistant phenotype, as well as generating cross-resistance to other medical azoles in some cases.

14.
Med Trop Sante Int ; 3(1)2023 03 31.
Artículo en Francés | MEDLINE | ID: mdl-37389374

RESUMEN

Background-Rationale: The diagnosis of Loa loa microfilaremia consists in the observation, using a microscope, of microfilariae in a sample of peripheral blood spread on a slide and subsequently stained (the "blood smear technique"). The accurate quantification of Loa loa microfilaremia is important because the choice of the first intention treatment depends on the patient's microfilaremia: severe adverse events can occur in individuals with high microfilarial densities when treated with ivermectin or diethylcarbamazine, the latter drug being the only one which can definitively cure the infection. However, despite the widespread usage of this technique and its role in guiding clinical management of the patient, estimates of its reliability remain scarce. Materials and methods: We evaluated the reliability (reproducibility and repeatability) of blood smear technique using several sets of 10 L. loo-positive slides, randomly selected, and considered the results with regard to regulatory requirements. The slides had been prepared as part of a clinical trial conducted in Sibiti, Republic of Congo, a region where loiasis is endemic. Results: The estimated and acceptable coefficients of repeatability (NB: the lower, the better) were 13.6% and 16.0%, respectively. The estimated and acceptable coefficients of intermediate reliability (reproducibility) were 15.1% and 22.5%, respectively. The poorest coefficient of intermediate reliability was 19.5% when the tested parameter was related to the technician who performed the readings (10.7% when the reading day was changed). The inter-technician coefficient of variation assessed using 1876 L. loo-positive slides was 13.2%. The coefficient of inter-technician variation considered acceptable was estimated at 18.6%. Discussion-Conclusion. All estimated coefficients of variability were lower than the calculated acceptable coefficients suggesting reliability of the technique, although the lack of laboratory references precludes any conclusion on the quality of this diagnosis. It is imperative to implement a quality system and standardization of procedures for the diagnosis of L. loo microfilaremia, both in endemic countries and in the rest of the world, where the demand for diagnosis has been increasing for years.


Asunto(s)
Dietilcarbamazina , Loa , Humanos , Animales , Congo , Reproducibilidad de los Resultados , Correlación de Datos , Dietilcarbamazina/uso terapéutico , Microfilarias
15.
J Mycol Med ; 33(3): 101410, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37356368

RESUMEN

AIMS: The rare yeast species Lodderomyces elongisporus, Kodamaea ohmeri, Cyberlindnera fabianii, and Wickerhamomyces anomalus are increasingly implicated in severe mycoses in immunocompromised patients. This study aimed to assess the prevalence of uncommon yeast species in Côte d'Ivoire. METHODS: The yeast isolates from superficial samples, mainly vaginal swabs, were collected at the Pasteur Institute of Abidjan in a study on the molecular epidemiology of clinical yeast species. Identification relied on MALDI-TOF MS and ITS sequence analysis. Antifungal susceptibility testing was performed using the CLSI method. RESULTS: Of the 315 strains analysed from 227 outpatients, 14 belonged to 4 uncommon species: Lodderomyces elongisporus, Kodamaea ohmeri, Cyberlindnera fabianii, and Wickerhamomyces anomalus. None exhibited elevated fluconazole, amphotericin B, caspofungin, ketoconazole, or flucytosin MIC. CONCLUSIONS: The presence of these rare yeasts represents a risk in immunocompromised people. Their adequate and timely identification is a priority. Overall, enhancing the mycoses diagnostic capacities in Côte d'Ivoire, and more generally in African clinical laboratories with limited resources is a critical aim.


Asunto(s)
Hongos , Micosis , Femenino , Humanos , Côte d'Ivoire/epidemiología , Levaduras , Micosis/epidemiología
16.
J Fungi (Basel) ; 8(3)2022 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-35330229

RESUMEN

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 carry or spread the most pathogenic species (i.e., species belonging to the C. neoformans and C. gattii complexes), as well as lesser-studied species (non-neoformans/gattii Cryptococcus and former Cryptococcus spp.), 669 birds belonging to 89 species received for care over a two-year period at the Centre de Protection de la Faune Sauvage of Villeveyrac (Bird Protection League nongovernmental organization (NGO) care center) were sampled. Samples were cultured, and Cryptococcus and former Cryptococcus yeasts were identified by PCR sequencing. The purpose was to evaluate whether there was any health risk to local populations or care personnel in aviaries and gather new data on the ecological niches of lesser-known species. One hundred and seven birds (16%) were found to be positive for at least one Cryptococcus or former Cryptococcus species. No yeasts belonging to the highly pathogenic C. neoformans or C. gattii complexes were isolated. However, diversity was notable, with 20 different Cryptococcus or former Cryptococcus species identified. Furthermore, most bird-yeast species associations found in this study have never been described before.

18.
Mycoses ; 54(4): e62-8, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20113400

RESUMEN

Caspofungin is a member of the echinocandin class of antifungal compounds that inhibit 1,3-ß-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 albicans isolates presenting reduced susceptibility to CAS were studied in comparison with a reference strain. Two C. albicans isolates presenting high minimal inhibitory concentrations (MIC = 8 µg ml(-1) ) were selected: one isolate obtained in the laboratory under continuous antifungal selection pressure (CaIn-R) and one clinical isolate (CaClin-R) from a patient with a therapeutic failure. Results showed that after 24 h of CAS exposure, CaIn-R and CaClin-R presented a partial growth inhibition in comparison with the reference strain. Moreover, scanning electron microscopy and transmission electron microscopy studies showed that the cell walls of CaIn-R and CaClin-R were less altered than that of the reference strain. These observations suggested that although CaIn-R and CaClin-R cells were misshapen after CAS exposure, cell lysis was limited after 24 h of treatment indicating higher survival ability for CaIn-R and CaClin-R in the presence of CAS.


Asunto(s)
Antifúngicos/toxicidad , Candida albicans/efectos de los fármacos , Equinocandinas/toxicidad , Candida albicans/aislamiento & purificación , Candida albicans/fisiología , Candida albicans/ultraestructura , Candidiasis/tratamiento farmacológico , Candidiasis/microbiología , Caspofungina , Pared Celular/efectos de los fármacos , Pared Celular/ultraestructura , Farmacorresistencia Fúngica , Humanos , Lipopéptidos , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión
19.
PLoS Negl Trop Dis ; 15(4): e0009354, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33878105

RESUMEN

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 reported after ivermectin administration in VigiBase, the World Health Organization's global individual case safety reports database and analyze their frequency relative to the frequency of these events after other antinematodal drugs reported in SSA and other areas of the world (ROW). METHODS: All antinematodal-related sADRs were extracted from VigiBase. Disproportionality analyses were conducted to investigate nervous, cutaneous, psychiatric, respiratory, renal, hepatic and cardiac suspected sADRs reported after ivermectin and benzimidazole drug administration across the world, in SSA and RoW. PRINCIPAL FINDINGS: 2041 post-ivermectin or post-benzimidazole suspected sADRs were identified including 667 after ivermectin exposure (208 in SSA and 459 in the RoW). We found an increased reporting for toxidermias, encephalopathies, confusional disorders after ivermectin compared to benzimidazole drug administration. Encephalopathies were not only reported from SSA but also from the RoW (adjusted reporting odds ratios [aROR] 6.30, 95% confidence interval: 2.68-14.8), highlighting the fact these types of sADR occur outside loiasis endemic regions. CONCLUSION: We described for the first time suspected sADRs associated with ivermectin exposure according to geographical origin. While our results do not put in question ivermectin's excellent safety profile, they show that as for all drugs, appropriate pharmacovigilance for adverse reactions is indicated.


Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Ivermectina/efectos adversos , Adolescente , Adulto , África del Sur del Sahara/epidemiología , Anciano , Bases de Datos Factuales , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Farmacovigilancia , Adulto Joven
20.
PLoS Negl Trop Dis ; 13(11): e0007812, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31738768

RESUMEN

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 Cryptococcus neoformans (serotype A) species complex, with 93% being VNI and 7% being VNII. Cryptococcus deuterogattii VGII (serotype B) represented 16.7% of the strains, while C. neoformans/C. deneoformans VNIII (serotype AD) hybrids accounted for 15.1% of the strains. One strain (0.4%) was not identifiable. Nine different sequence types (STs 5, 6, 23, 40, 93, 207, 311, and a new ST; 555) were identified in the C. neoformans population, while the C. deuterogattii population comprised the single ST 173. The distribution of the strains showed that, while the majority of patients (9/13) harboured a single sequence type, 4 patients showed mixed infections. These patients experienced up to 4 shifts in strain content either at the species and/or ST level during their follow-up. This evolution of diversity over time led to the co-existence of up to 3 different Cryptococcus species and 4 different ST within the same individual during the course of infection. Susceptibility testing showed that all strains were susceptible to amphotericin B while 3.6% of them had a none-wild type phenotype to 5-flucytosine. Concerning fluconazole, 2.9% of C.neoformans serotype A strains and 2.4% of C. deuterogattii had also respectively a none-wild type phenotype to this molecule. All C. neoformans x C. deneoformans serotype AD hybrids had however a wild type phenotype to fluconazole. The present study showed that mixed infections exist and could be of particular importance for care outcomes. Indeed, (i) the different Cryptococcus species are known to exhibit different virulence and different susceptibility patterns to antifungal drugs and (ii) the strains genetic diversity within the samples may influence the susceptibility to antifungal treatment.


Asunto(s)
Antifúngicos/uso terapéutico , Coinfección , Cryptococcus/efectos de los fármacos , Cryptococcus/genética , Variación Genética , Infecciones por VIH/complicaciones , Meningitis Criptocócica/complicaciones , Adulto , Anfotericina B/uso terapéutico , Coinfección/microbiología , Criptococosis , Cryptococcus/aislamiento & purificación , Cryptococcus neoformans/genética , Femenino , Fluconazol/uso terapéutico , Flucitosina/uso terapéutico , Estudios de Seguimiento , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Tipificación de Secuencias Multilocus , Técnicas de Tipificación Micológica
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