Levures

Levures
  • 文章类型: Journal Article
    到目前为止报道的140000左右的真菌物种是基于不同的标准,如形态学,生理,交配,和(或)分子特征。不一致现象在用于分离密切相关物种的性状中很常见,通常很难比较基于不同物种识别标准定义的真菌分类群。尽管已经进行了基于DNA序列的分类和鉴定,尚未达成共识,主要是由于所提出的一个或几个基因的内在限制。这里,我认为,观察到的不一致的根本原因是物种形成是一个随机过程,不同性状的出现和固定受到许多非确定性因素的不同影响,例如种群规模,随机突变,复制模式,由相互作用的生物和非生物因素施加的选择,和偶然事件。每个物种概念都试图捕捉连续物种形成过程中出现的一个或几个性状。我建议基于基因组序列的分类和鉴定系统可以统一和稳定真菌分类学,并有助于将分类学与真菌生物学的其他领域整合。基因组物种概念可以类似地用于其他真核微生物群以及植物和动物。
    The 140 000 or so fungal species reported so far are heterogeneously defined based on varying criteria such as morphological, physiological, mating, and (or) molecular features. Incongruences are common among traits used to separating closely related species and it is often difficult to compare fungal taxonomic groups defined based on different species recognition criteria. Though DNA sequence-based classification and identification have been made, a consensus has not been reached, primarily due to intrinsic limitations in the proposed one or a few genes. Here, I argue that the fundamental reason for the observed inconsistencies is that speciation is a stochastic process with the emergence and fixation of different traits influenced differently by many non-deterministic factors such as population size, random mutation, mode(s) of reproduction, selection imposed by interacting biotic and abiotic factors, and chance events. Each species concept attempts to capture one or a few traits emerged in the continuous process of speciation. I propose that a genome sequence-based classification and identification system could unify and stabilize fungal taxonomy and help integrate taxonomy with other fields of fungal biology. The genomic species concept could be similarly argued for other groups of eukaryotic microbes as well as for plants and animals.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: Journal Article
    目的:本研究的目的是鉴定来自商业的酵母。
    方法:这项描述性横断面调查涉及2017年8月至9月在市场上出售的103份attiéké样品。这项研究是在科特迪瓦巴斯德研究所的真菌学实验室进行的。将样品接种在YGC培养基上。对阳性培养物的菌落进行计数并再次接种在色原培养基上。通过MALDI-TOF质谱(VitekMSbioMérieux)进行酵母物种的鉴定。
    结果:作为一个整体,63个样本被真菌污染,即总患病率为61.1%。鉴定出59个酵母,即57.2%。念珠菌是最常见的分离(62.7%),其次是白色念珠菌(8.5%),克氏念珠菌(8.5%)和热带念珠菌(8.5%)。念珠菌代表6.8%的分离酵母。酵母的平均载量为10,124×102CFU/g,对Abobo公社的商业Attiéké的污染很高。
    结论:酵母菌对Attiéké的污染是现实。Rugosa是最常见的分离。有必要调查食物链以确定污染源。
    OBJECTIVE: This study aims to identify yeasts from commercial attiéké.
    METHODS: This descriptive cross-sectional survey involving 103 samples of attiéké sold on the market from August to September 2017. It was conducted from the mycology laboratory of the Institut Pasteur of Côte d\'Ivoire. The samples were seeded on YGC medium. The colonies of positive culture were counted and seeded again on chromogen medium. Identification of yeasts species was carried out by MALDI-TOF mass spectrometry (Vitek MS bioMérieux).
    RESULTS: As a whole, 63 samples were contaminated with fungi i.e. an overall prevalence of 61.1 %. Fifty-nine of yeasts were identified i.e. 57.2 %. Candida rugosa was most frequently isolated (62.7 %), followed by Ccandida albicans (8.5 %), Candida krusei (8.5 %) et Candida tropicalis (8.5 %). Geotrichum candidum represented 6.8 % isolated yeasts. The yeast average load is 10,124×102 CFU/g with high contamination of commercial attiéké in the commune of Abobo.
    CONCLUSIONS: The contamination of attiéké by yeasts is a reality. C. rugosa was most frequently isolated. It would be necessary to investigate the food chain to determine the source of contamination.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    OBJECTIVE: Fungal interdigital tinea pedis are poorly documented in Ivory Coast. This study aimed to determine the distribution of fungal species and contributing factors of the disease among policemen in Abidjan.
    METHODS: Our cross-sectional study was carried out at the police school in Abidjan. Our patients consisted of symptomatic or non-symptomatic police students. Samples of scales or serosities taken from inter-toes spaces were examinated with KOH mount and cultured on Sabouraud-chloramphenicol and Sabouraud-chloramphenicol-actidione media. The method of identification depended on the observed fungus.
    RESULTS: Among the 303 police students with clinical lesions of the inter-toe folds, 233 (76.9%; IC 95%=71.9-81.4) had a positive diagnosis after mycological examination. Lesions were predominantly located in the 3rd and 4th interdigital plantar spaces, with desquamation (100%) followed by maceration (82.5%) as the predominant functional sign. Dermatophytes accounted for 86.3% of the strains isolated with as majority species : Trichophyton interdigitale (40.3%), Microsporum langeronii (30.0%) and Trichophyton rubrum (15.5%). Yeasts accounted for 13.7% of the strains with Candida albicans (7.7%) as the most found species. The duration at the police school (P=0.004) and the practice of sports activities (P=0.0001) were statistically associated with the occurrence of the disease.
    CONCLUSIONS: A good hygiene of feet would reduce the incidence of the disease among the defense and security forces. Also, investigations for the influence of the seasons in the occurrence of interdigital tinea pedis will allow a better understand of epidemiology of this dermatomycosis.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: Journal Article
    OBJECTIVE: The aim was to identify the incidence of the causal agents from dermatophytes, non-dermatophytes and yeasts in Assiut Governorate employing, beside the morphological and physiological techniques, the genotypic ones.
    METHODS: Samples from infected nails, skin and hair were taken from 125 patients.
    METHODS: Patients who presented with onychomycosis, tinea capitis, tinea corporis, tinea cruris and tinea pedis during the period from February 2012 to October 2015 were clinically examined and diagnosed by dermatologists and were guided to Assiut University Mycological Centre for direct microscopic examination, culturing and identification.
    RESULTS: Onychomycosis was the most common infecting (64.8% of the cases) followed by tinea capitis (17.6%). Direct microscopic preparations showed only 45 positive cases, while 96 cases showed positive cultures. Infections were more frequent in females than males. Fifty-one fungal species and 1 variety were obtained. Yeasts were the main agents being cultured from 46.02% of total cases. Non-dermatophytes were the second etiologic agents. Aspergillus was responsible for infecting 19.47% of total cases and dermatophytes appeared in only 15.93% of the cases.
    CONCLUSIONS: Yeasts were the main causal agents followed by non-dermatophytic fungi (mainly species of Aspergillus, then Alternaria, Scopulariopsis and Fusarium). Both direct microscopic preparations and culturing are recommended for mycological evaluation of clinical specimens. Sequence analysis of ITS region is recommended for yeast identification.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: Journal Article
    背景:浅表真菌感染,尤其是皮肤,头皮和指甲非常常见,已在世界范围内报道。这些真菌病最常见的病原体是皮肤癣菌,酵母和霉菌.然而,这些代理随时间而变化,并取决于许多因素,包括地理位置。这项研究的目的是确定在达喀尔(塞内加尔)的LeDantec大学医院诊断的浅表真菌病的病原体。
    方法:该研究涉及2011年1月至2015年12月在LeDantec医院寄生虫学和真菌学实验室接受的1851名门诊患者。每个患者都受益于直接检查和真菌学培养。
    结果:在1851名患者中,633例确诊为浅表真菌病,患病率为34.2%。患者年龄为2个月至81岁,平均年龄为31岁。女性(70.3%)的浅表真菌病比男性(29.7%)多,成年人占39%(39.3%)。确定的病原体是:皮肤癣菌(58%),酵母(36.7%)和非皮肤癣丝状真菌(NDFF,5.3%)。最孤立的物种是:白色念珠菌(26.9%),南方毛癣菌(24.9%)和红色毛癣菌(13.7%)。这些真菌负责不同的临床方面,孤立和其他相关。在孤立的临床方面,到目前为止,影响头发(头癣)的比例最大,为44.8%,其次是甲癣(34.5%)。尤其是头癣和手癣(2.4%)以及与指间癣相关的脚趾甲真菌病(2.7%)。头癣剂仅为皮肤癣菌,主要剂为T.soudanense,占47,8%。癣剂是酵母(79%),皮肤癣菌(18%)或NDFF(3%),发现最多的物种是白色念珠菌(63.9%)。皮肤癣菌,酵母菌和霉菌分别在儿童和年轻人中发现得更多,老年人和年轻人,老年人和老年人。
    结论:最终,这些流行病学数据应能更好地诊断和治疗浅表真菌病.
    BACKGROUND: Superficial fungal infections, particularly of the skin, scalp and nails are very common and have been reported worldwide. The most common causative agents of these mycoses are dermatophytes, yeasts and molds. However, these agents vary with time and depend on many factors including the geography. The objective of this study was to identify the causative agents of superficial mycoses diagnosed at the Le Dantec University Hospital in Dakar (Senegal).
    METHODS: The study concerned 1851 outpatients received in the parasitological and mycological laboratory of Le Dantec hospital during the period from January 2011 to December 2015. Every patient benefited from direct examination and mycological culture.
    RESULTS: Among the 1851 patients, 633 were confirmed with superficial mycoses and the prevalence was 34.2 %. The age of patients ranged from two months to 81 years with a mean age of 31 years. Superficial mycoses were found more in women (70.3 %) than men (29.7 %) and a little more than thirty-nine percent (39.3 %) were adults. The causative agents identified were: dermatophytes (58 %), yeast (36.7 %) and non-dermatophytic filamentous fungi (NDFF, 5.3 %). The most isolated species were: Candida albicans (26.9 %), Trichophyton soudanense (24.9 %) and T. rubrum (13.7 %). These fungi were responsible for different clinical aspects, isolated and other associated. Among the isolated clinical aspects, those affecting hair (tinea capitis) were by far the largest with 44.8 %, followed by tinea unguium (34.5 %). Associations were especially type of tinea capitis and tinea manuum (2.4 %) and toenails onychomycosis associated with interdigital tinea pedis (2.7 %). Tinea capitis agents were exclusively dermatophytes and the predominant agent was T. soudanense with 47,8 %. Tinea unguium agents were yeast (79 %), dermatophytes (18 %) or NDFF (3 %) and the most found species was C. albicans (63.9 %). Dermatophytes, yeasts and molds were respectively found more in children and young adults, older adults and young adults and older adults and the elderly.
    CONCLUSIONS: In definitive, these epidemiological data should enable better diagnostic and therapeutic management of superficial mycoses.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    Fungal interdigital tinea pedis (FITP) is the most frequent dermatomycosis in industrial countries. In African tropics, it\'s a rare motive of consultation and is discovered while complicated. The aims of this article were: to determine the frequency of interdigital tinea pedis among overall mycological analysis in our laboratory; to study epidemiological, clinical and mycological aspects of FITP in outpatients attending the Le Dantec mycology laboratory in Dakar. A total of 62 males (60%) and 42 females (40%), mean age: 43.15 years (range: 11-81 years), were received from January 2011 to December 2015 for suspicion of FITP. Skin specimens were taken from all patients for microscopy and fungal culture. The frequency of ITP represents 5.6% (104/1851) among our overall mycological analysis. FITP was confirmed in 68 patients (SPI=65.38%), mainly located between the 4th and 5th toes and 71 fungal species were isolated (CPI=68.27%). Among patients with confirmed FITP, there were 38 males (56%) and 30 females (44%). The prevalence was highest in patients between 44 and 54 years (26%). Candida albicans, Fusarium solani and Trichophyton interdigitale were shown to be the most common pathogens respectively for yeasts (39%), non-dermatophytic filamentous fungi (NDFF; 21%) and dermatophytes (11%). So FITP isn\'t a common reason for consultation in Dakar but its simple parasitic index (SPI) is still very high and dermatophytes formerly the main causative agents are being relegated to third place behind yeasts and NDFF.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: Journal Article
    The human mycobiome includes 390 fungal species detected on the skin, in the vagina, in the oral cavity, and in the digestive tract that includes 335 species and 158 genera. Among these, 221 species are found only in the digestive tract, 88 only in the oral cavity, and 26 in both. These species belong to 126 genera of yeast and filamentous fungi, of the Ascomycota, Basidiomycota, and Zygomycota phyla. Forty species were identified only by culture, 188 species by molecular techniques, and 19 species with both techniques. Fungal diversity does not differ significantly according to sex but Basidiobolus ranarum is significantly more prevalent in male individuals and Paecilomyces fumosoroseus in female individuals. Fungal diversity is significantly higher in adults than in infants. Only 42 species are identified in the course of inflammatory bowel disease, with 27 species specific to IBD. Twenty-nine are identified in HBV infected patients including 17 specific species, and 11 in HIV-infected patients with the specific Histoplasma capsulatum. Genotyping proved that the gut mycobiome was a source of fungal infection caused by Candida albicans and Candida glabrata. The authors suggest updating the repertoire of the human digestive tract in healthy individuals and patients. Fungal culturomics must be intensified to complete this repertoire.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: Journal Article
    Chloramphenicol is a bacteriostatic antimicrobial agent but its antifungal activity is not known. The present study aimed to investigate the activity of chloramphenicol against 30 representative yeasts. The antimicrobial assay of chloramphenicol (50mg/mL; 100mg/mL and 200mg/mL) was determined by the disc diffusion method using Mueller-Hinton agar against 30 representative yeast strains. Zone of inhibition was read after 48-72h incubation at 37°C and results were compared with some standard antifungal agents. Most of the tested yeasts (73.3%) showed inhibition zones (5 up to 35mm) to chloramphenicol impregnated discs (200mg/mL). Three out of the four tested Candida albicans as well as Candida famata, Candida glabrata, Candida haemolonei and Cryptococcus neoformans showed no inhibition zones to chloramphenicol (200mg/mL). Caspofungin acetate (50mg/mL) inhibited 83.3% of the strains; ketoconazole (200mg/mL) 70% and metronidazole 10%. Chloramphenicol discs: 50 and 100mg/mL showed less activity (6.7% and 36.7%, respectively) compared to the 200mg discs; whereas chloramphenicol (BBL; 3μg/mL) inhibited 13.3% of the strains. The anti-yeast activities of chloramphenicol were comparable to other known antifungal compounds. Moreover, it is cheap, has fewer side effects and its inclusions in selective fungal media such as Mycosel have to be questioned.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: English Abstract
    通过真菌学检查确认甲癣的真菌起源是必不可少的。为此,在培养生物样本的同时,对指甲碎片和指甲下材料进行敏感和翔实的直接检查是原始的。在直接检查技术中,并受到组织病理学参考技术(“高碘酸-希夫试剂”反应)的启发,根据Hotchkiss和MacManus的简化的PAS染色技术是首选技术。易于实施且非常敏感,它可以立即正式确认甲癣的诊断,提到真菌的类型(酵母,皮肤癣菌,菌丝机会性),并怀疑可能有多种参与。
    Confirmation of fungal origin of onychopathy by mycological examination is essential. For that purpose, in parallel to the cultivation of biological samples, achieving a sensitive and informative direct examination of nail fragments and subungual material is primordial. Among the direct examination techniques, and inspired from a technique of reference in histo-pathology (the \"periodic acid-Schiff reagent\" reaction), the simplified technique of PAS staining according to Hotchkiss and MacManus is the technique of choice. Easy to implement and very sensitive, it can immediately and formally confirm the diagnosis of onychomycosis, mention the type of fungus (yeast, dermatophyte, Hyphomycete opportunistic) and suspect a possible multiple involvement.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: English Abstract
    Onychomycosis represents about 50% of ungueal pathology. Dermatophytes (especially Trichophyton rubrum and Trichophyton interdigitale) are the main species involved in tinea pedis. Yeasts of the Candida (Candida albicans, Candida parapsilosis,...) genus are predominant on hands and very often associated with ungueal disease and perionyxis. Fungi other than the classic dermatophytes and yeasts can be rarely isolated from nail diseases. Among them, species belonging to Scopulariopsis, Aspergillus and Fusarium genus are mainly found, but their involvement in the disease must be proved. Other fungi, presenting a special affinity to keratin (pseudodermatophytes), such as Neoscytalidium dimidiatum (ex Scytalidium dimidiatum) from tropical and subtropical areas and Onychocola canadensis from Northern America and Europe, are considered as real pathogens in nail diseases. A multidisciplinary approach, including clinicians and biologists, is required to confirm the mycosis. This comparative review emphasizes the importance of histological examination, as well as molecular approaches, which are very contributive to the diagnosis of onychomycosis. The role of the laboratory is to identify at the species level the fungus isolated from nail scrapings and to show its involvement in the ungueal lesions.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

公众号