RESUMEN
Four yeast isolates were obtained from rotting wood and galleries of passalid beetles collected in different sites of the Brazilian Amazonian Rainforest in Brazil. This yeast produces unconjugated allantoid asci each with a single elongated ascospore with curved ends. Sequence analysis of the internal transcribed spacer-5.8 S region and the D1/D2 domains of the large subunit ribosomal RNA (rRNA) gene showed that the isolates represent a novel species of the genus Spathaspora. The novel species is phylogenetically related to a subclade containing Spathaspora arborariae and Spathaspora suhii. Phylogenomic analysis based on 1884 single-copy orthologs for a set of Spathaspora species whose whole genome sequences are available confirmed that the novel species represented by strain UFMG-CM-Y285 is phylogenetically close to Sp. arborariae. The name Spathaspora marinasilvae sp. nov. is proposed to accommodate the novel species. The holotype of Sp. marinasilvae is CBS 13467 T (MycoBank 852799). The novel species was able to accumulate xylitol and produce ethanol from d-xylose, a trait of biotechnological interest common to several species of the genus Spathaspora.
Asunto(s)
Escarabajos , Filogenia , Bosque Lluvioso , Saccharomycetales , Madera , Xilosa , Animales , Madera/microbiología , Escarabajos/microbiología , Brasil , Saccharomycetales/genética , Saccharomycetales/clasificación , Saccharomycetales/aislamiento & purificación , Saccharomycetales/metabolismo , Xilosa/metabolismo , Fermentación , ADN de Hongos/genética , Análisis de Secuencia de ADNRESUMEN
Two isolates representing a novel species of the genus Wickerhamiella were obtained in India from nectar of flowers of Lantana camara, an ornamental exotic species native to Central and South America. Phylogenetic analyses of the D1/D2 domain of the 26S large subunit (LSU) rRNA gene, internal transcribed spacer (ITS) region, and physiological characteristics, supported the recognition of the novel species, that we designate Wickerhamiella lachancei sp. nov (MycoBank no. MB851709), with MCC 9929T as the holotype and PYCC 10003T as the isotype. Considering pairwise sequence similarity, the type strain of the novel species differs from the type strain of the most closely related species, Wickerhamiella drosophilae CBS 8459T, by 16 nucleotide substitutions and two gaps (3.9â% sequence variation) in the D1/D2 region (560 bp compared) and 28 nucleotide substitutions and five gaps (7.22â% sequence variation) in the ITS region (444 bp compared).
Asunto(s)
ADN de Hongos , ADN Espaciador Ribosómico , Flores , Lantana , Filogenia , Análisis de Secuencia de ADN , India , Flores/microbiología , ADN de Hongos/genética , Lantana/microbiología , ADN Espaciador Ribosómico/genética , Datos de Secuencia Molecular , Técnicas de Tipificación Micológica , ARN Ribosómico/genética , Saccharomycetales/genética , Saccharomycetales/aislamiento & purificación , Saccharomycetales/clasificaciónRESUMEN
Four yeast strains belonging to the basidiomycetous yeast genus Mrakia were isolated from diverse habitats in the Ny-Ålesund region (Svalbard, High Arctic): two from vascular plants, one from seawater and one from freshwater. Phylogenetic analysis, based on the ITS region and the D1/D2 domain of the 28S rRNA gene, identified these four strains as representing two novel species within the genus Mrakia. The names Mrakia polaris sp. nov. (MycoBank number: MB 852063) and Mrakia amundsenii sp. nov. (MycoBank number: MB 852064) are proposed. These two new species show distinct psychrophilic adaptations, as they exhibit optimal growth at temperatures between 10 and 15°C, while being unable to grow at 25°C. The holotype of M. polaris sp. nov. is CPCC 300345T, and the holotype of M. amundsenii sp. nov. is CPCC 300572T.
Asunto(s)
ADN de Hongos , Filogenia , Agua de Mar , Análisis de Secuencia de ADN , Regiones Árticas , ADN de Hongos/genética , Agua de Mar/microbiología , Técnicas de Tipificación Micológica , Svalbard , ARN Ribosómico 28S/genética , Basidiomycota/genética , Basidiomycota/clasificación , Basidiomycota/aislamiento & purificación , Agua Dulce/microbiología , Ecosistema , Frío , Saccharomycetales/clasificación , Saccharomycetales/genética , Saccharomycetales/aislamiento & purificaciónRESUMEN
INTRODUCTION: Kodamaea ohmeri is a rare, recognized pathogen that has previously been isolated from environmental sources. The patients commonly affected by this yeast include immunocompromised as well as immunocompetent patients having several associated risk factors. METHODOLOGY: We report three cases in which K. ohmeri was isolated from blood using Bact T/ALERT. Identification was carried out by MALDI-TOF MS (Vitek-MS, BioMérieux, Marcy-l'Etoile, France) in addition to color characteristics on chromogenic media. The patients had diminished immune response on account of a multitude of comorbidities. RESULTS: K. ohmeri can be misidentified as Candida tropicalis, Candida albicans, or Candida hemolounii by conventional methods; correct and timely identification can be achieved by MALDI-TOF MS. Antifungal susceptibility breakpoints for K. ohmeri are currently not defined. An Echinocandin was added to the treatment regimen of all three of the cases. CONCLUSIONS: Identification of K. ohmeri using conventional methods is difficult and unusual yeasts should be carefully observed, especially upon prolonged incubation.
Asunto(s)
Antifúngicos , Huésped Inmunocomprometido , Saccharomycetales , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Humanos , Antifúngicos/uso terapéutico , Antifúngicos/farmacología , Masculino , Saccharomycetales/aislamiento & purificación , Saccharomycetales/efectos de los fármacos , Femenino , Persona de Mediana Edad , Anciano , Infecciones Fúngicas Invasoras/tratamiento farmacológico , Infecciones Fúngicas Invasoras/diagnóstico , Infecciones Fúngicas Invasoras/microbiología , Técnicas MicrobiológicasRESUMEN
ABSTRACT: Kodamaea ohmeri is a rare opportunistic pathogen belonging to Saccharomycetes family. This yeast was also formerly known as Yamadazyma ohmeri or Pichia ohmeri . This opportunistic pathogen causes illness that typically affects people with impaired immune system. In this report, we discuss a fatal case involving a woman in her late 30s who was admitted to the hospital on the sixth day of her sickness after being given a COVID-19 Category 5A diagnosis. For COVID-19, she received subcutaneous heparin, cefuroxime, and intravenous corticosteroids. She was diagnosed with secondary bacterial and fungal infections in the ICU. Multiple antibiotics and antifungal were given to treat bacterial and fungal infections. An unusual fungus, Kodamaea ohmeri , was isolated from the clinical sample. On day 36, she succumbed to her infection in the ICU. The cause of death was multidrug-resistant sepsis with multiple organ failures due to COVID-19 infection, worsened by an embolism and trachea damage during a tracheostomy. To effectively manage K. ohmeri , clinicians and microbiologists must identify and be aware of this emerging human opportunistic pathogen, which can co-infect debilitated patients such as COVID-19 patients, for effective management.
Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Femenino , COVID-19/complicaciones , Resultado Fatal , Adulto , Malasia , Micosis/tratamiento farmacológico , Micosis/diagnóstico , Micosis/microbiología , Saccharomycetales/aislamiento & purificación , Saccharomycetales/efectos de los fármacos , Saccharomycetales/patogenicidad , Antifúngicos/uso terapéutico , Coinfección/microbiología , Infecciones Oportunistas/tratamiento farmacológico , Infecciones Oportunistas/microbiologíaRESUMEN
We report a case of endocarditis months after a Bentall procedure. This was caused by Candida Lusitaniae, in an immunocompetent patient with a recent SARS-CoV-2 infection. The patient underwent a new Bentall procedure. SARS-CoV-2 has been associated with co-infection by Candida species since the beginning of the pandemic, nevertheless, Candida Lusitaniae remains a very uncommon causative agent of prosthetic endocarditis. We suggest a possible role of the SARS-CoV-2, which may have delayed the diagnosis of endocarditis and the appropriate therapy.
Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Endocarditis , Saccharomycetales , COVID-19/epidemiología , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Endocarditis/diagnóstico , Endocarditis/microbiología , Humanos , Huésped Inmunocomprometido , Saccharomycetales/aislamiento & purificaciónRESUMEN
Strains SU22T (TBRC 14875T) and FLA11.5, representing a novel anamorphic yeast species, were respectively isolated from a fruiting body of a Coprinus species and an inflorescence of a Coffea species collected in Thailand. Analysis of the sequences of the D1/D2 domains of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) regions showed that the two strains differed by two nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene and were identical in the ITS regions. Wickerhamiella drosophilae CBS 8459T was the most closely related species, but with 24-26 nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene and 24 nucleotide substitutions in the ITS regions. A phylogenetic analysis, based on the sequences of the D1/D2 domains, indicated that the two strains represented a species in the genus Wickerhamiella which was distinct from other recognized species of the genus. Therefore, the two strains were assigned as a novel species, for which we propose the name Wickerhamiella nakhonpathomensis f.a. sp. nov. The holotype is TBRC 14875T (isotype PYCC 8914T). The MycoBank number of the novel species is MB 840833.
Asunto(s)
Agaricales , Flores/microbiología , Filogenia , Saccharomycetales , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Ácidos Grasos/química , Técnicas de Tipificación Micológica , Saccharomycetales/clasificación , Saccharomycetales/aislamiento & purificación , Análisis de Secuencia de ADN , TailandiaRESUMEN
Seven yeast strains, representing a single novel anamorphic species, were isolated in Thailand. They consisted of five strains (DMKU-MRY16T, DMKU-SK18, DMKU-SK25, DMKU-SK30 and DMKU-SK32) obtained from five different mushrooms, and two strains (ST-224 and 11-14.2) derived from insect frass and soil, respectively. The pairwise sequence analysis indicated that all seven strains had identical sequences in the D1/D2 domains of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region. Metahyphopichia silvanorum was the most closely related species, but with 11.9-12.4% nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene and 13.1-13.3% nucleotide substitutions in the ITS region. The phylogenetic analyses based on the concatenated sequences of the ITS region and the D1/D2 domains of the LSU rRNA gene showed that the seven strains form a well-separated subclade in a clade containing M. silvanorum and Metahyphopichia laotica with high bootstrap support. A phylogenetic analysis of a multilocus dataset including the small subunit (SSU) rRNA gene, the ITS region, the D1/D2 domains of the LSU rRNA gene, translation elongation factor 1-alpha gene, actin gene and the RNA polymerase II subunit 2 gene, confirmed the presence of the monophyletic clade that also includes M. silvanorum and M. laotica, and strongly supported the phylogenetic isolation of the seven strains from its neighbouring species. Therefore, the seven strains were assigned as a single novel species of the genus Metahyphopichia, according to their phylogenetic relationships. The name Metahyphopichia suwanaadthiae sp. nov. is proposed to accommodate the seven strains. The holotype is DMKU-MRY16T (TBRC 11775T=NBRC 114386T=PYCC 8655T). The MycoBank number of the novel species is MB 841280. In addition, Candida silvanorum is reassigned to the genus Metahyphopichia. The MycoBank number of M. silvanorum comb. nov. is MB 841279.
Asunto(s)
Candida/clasificación , Filogenia , Saccharomycetales , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Técnicas de Tipificación Micológica , ARN Ribosómico 16S/genética , Saccharomycetales/clasificación , Saccharomycetales/aislamiento & purificación , Análisis de Secuencia de ADN , TailandiaRESUMEN
Aiming to broaden the base of knowledge about wild yeasts, four new indigenous strains were isolated from corn residues, and phylogenetic-tree assemblings on ITS and LSU regions indicated they belong to Meyerozyma caribbica. Yeasts were cultivated under full- and micro-aerobiosis, starting with low or high cell-density inoculum, in synthetic medium or corn hydrolysate containing glucose and/or xylose. Cells were able to assimilate both monosaccharides, albeit by different metabolic routes (fermentative or respiratory). They grew faster in glucose, with lag phases ~ 10 h shorter than in xylose. The hexose exhaustion occurred between 24 and 34 h, while xylose was entirely consumed in the last few hours of cultivation (44-48 h). In batch fermentation in synthetic medium with high cell density, under full-aerobiosis, 18-20 g glucose l-1 were exhausted in 4-6 h, with a production of 6.5-7.0 g ethanol l-1. In the xylose medium, cells needed > 12 h to consume the carbohydrate, and instead of ethanol, cells released 4.4-6.4 g l-1 xylitol. Under micro-aerobiosis, yeasts were unable to assimilate xylose, and glucose was more slowly consumed, although the ethanol yield was the theoretical maximum. When inoculated into the hydrolysate, cells needed 4-6 h to deplete glucose, and xylose had a maximum consumption of 57%. Considering that the hydrolysate contained ~ 3 g l-1 acetic acid, it probably has impaired sugar metabolism. Thus, this study increases the fund of knowledge regarding indigenous yeasts and reveals the biotechnological potential of these strains.
Asunto(s)
Glucosa/metabolismo , Saccharomycetales/metabolismo , Xilosa/metabolismo , Zea mays/microbiología , Ácido Acético , Aerobiosis , Biomasa , Medios de Cultivo/química , Fermentación , Lignina , Filogenia , Saccharomycetales/clasificación , Saccharomycetales/genética , Saccharomycetales/aislamiento & purificación , Xilitol/biosíntesisRESUMEN
In the present study, for the first time, high sensitive quantitative polymerase chain reaction (qPCR) and digital droplet polymerase chain reaction (ddPCR) assays were developed to detect and quantify total eumycetes with potential application in several food matrices and to specifically determine the level of contamination by Saccharomycopsis fibuligera and Wickerhamomyces anomalus cells directly in bread. Among the candidate target genes used to develop the assays, car1 gene was chosen to detect the two spoilage yeasts S. fibuligera and W. anomalus. The specificity of the PCR assays was tested using purified genomic DNA from 36 bacterial and fungal strains. The sensitivity of the assays was defined by using tenfold serial dilutions of genomic DNA starting from 106 cfu/mL to 1 cfu/mL of S. fibuligera and W. anomalus. Validation of the assays was achieved by enumeration of S. fibuligera and W. anomalus DNA copies from samples of artificially contaminated bread homogenates detecting up to 10 cfu/mL (0.06 ± 0.01 copies/µL) of W. anomalus by using ddPCR. In conclusion, the developed qPCR and ddPCR assays demonstrate strong performance in the early detection of S. fibuligera and W. anomalus in bread, representing promising tools for applying high-throughput approaches to regularly monitor bread quality.
Asunto(s)
Pan , Contaminación de Alimentos/análisis , Saccharomycetales/aislamiento & purificación , Saccharomycopsis , Pan/microbiología , Reacción en Cadena en Tiempo Real de la Polimerasa , Saccharomycopsis/aislamiento & purificación , Sensibilidad y Especificidad , LevadurasRESUMEN
Magnusiomyces and Geotrichum species are ascomycetous yeasts that can cause potentially life-threatening invasive fungal infections commonly referred to as geotrichosis. In this study, we aimed to estimate the incidence and mortality of these infections in a German tertiary care center. Furthermore, we evaluated the suitability of the fungal biomarkers galactomannan (GM) and ß-1,3-d-glucan (BDG), which are both recommended as surrogate markers for Magnusiomyces capitatus infection by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and the European Confederation of Medical Mycology (ECMM) joint clinical guidelines for the diagnosis and management of rare invasive yeast infections for detection of invasive geotrichosis. Cases meeting the inclusion criteria for invasive Magnusiomyces/Geotrichum infection were retrospectively identified. Serum samples and culture supernatants were analyzed with two commercially available fungal antigen tests (Platelia Aspergillus Ag EIA and Wako ß-glucan test). For a control cohort, outpatient samples sent for lues testing were included. Thirty-eight cases of Magnusiomyces/Geotrichum infection were identified over an 11-year observation period. In the majority of cases, the fungus was isolated from intra-abdominal specimens of patients with a history of abdominal surgery/procedures (n = 32). All cases of fungemia occurred exclusively in haemato-oncologic patients (n = 14). Thirty-day survival was 42% in the fungemia and 43% in the intra-abdominal geotrichosis group. Serum samples were available for 23 patients (14 bloodstream and nine intra-abdominal infections). While BDG sensitivity was 65%, none of the sera was GM positive. This finding was supported by in vitro experiments analyzing fungal culture supernatants: M. capitatus secretes significant amounts of BDG but not GM. Specificity was 96% for BDG and 100% for GM. Magnusiomyces and Geotrichum infections are not limited to haemato-oncologic patients. Contrasting the current ESCMID/ECMM recommendation, our results indicate that GM is no suitable biomarker for the diagnosis of Magnusiomyces infection. Contrarily, BDG sensitivity is comparable to that of candidemia.
Asunto(s)
Geotricosis , Geotrichum , Infecciones Fúngicas Invasoras , Mananos , Proteoglicanos , Saccharomycetales , beta-Glucanos , Biomarcadores/sangre , Galactosa/análogos & derivados , Geotricosis/sangre , Geotricosis/diagnóstico , Geotrichum/aislamiento & purificación , Humanos , Infecciones Fúngicas Invasoras/sangre , Infecciones Fúngicas Invasoras/diagnóstico , Mananos/sangre , Proteoglicanos/sangre , Estudios Retrospectivos , Saccharomycetales/aislamiento & purificación , Sensibilidad y Especificidad , beta-Glucanos/sangreRESUMEN
Non-Saccharomyces yeasts are important players during winemaking and may come from grapes grown in vineyards. To study the diversity of non-Saccharomyces yeasts on grape berry surfaces, 433 strains were isolated from different Cabernet Sauvignon vineyards grown in Henan Province. Our results demonstrated that these strains were classified into 16 morphotypes according to their growth morphology on Wallerstein Laboratory agar medium, and were identified as seven species from four genera-Hanseniaspora opuntiae, Hanseniaspora vineae, Hanseniaspora uvarum, Pichia occidentalis, Pichia kluyveri, Issatchenkia terricola and Saturnispora diversa-based on a series of molecular biological experiments. Hanseniaspora opuntiae was obtained from all sampling sites except Changyuan County, while Pichia kluyveri and Saturnispora diversa were only found in sites of Zhengzhou Grape Resource Garden and Minquan County, respectively. The site Minquan was home of the greatest species richness, while only one single species (Hanseniaspora opuntiae) was detected at NAPA winery from Zhengzhou or at Anyang County. Finally, this study suggested that the geographic distribution and diversity of non-Saccharomyces yeast populations on Cabernet Sauvignon grape berries were likely to be determined by a combination of grape varieties and environmental factors.
Asunto(s)
Biodiversidad , Frutas , Vitis , Levaduras , China , Granjas , Fermentación , Frutas/microbiología , Hanseniaspora/clasificación , Hanseniaspora/aislamiento & purificación , Pichia/clasificación , Pichia/aislamiento & purificación , Saccharomycetales/clasificación , Saccharomycetales/aislamiento & purificación , Vitis/microbiología , Vino/microbiología , Levaduras/clasificación , Levaduras/aislamiento & purificaciónRESUMEN
Four yeast isolates with an affinity to the genus Wickerhamiella were obtained from beach sand, a marine zoanthid and a tree exudate at different localities in Brazil. Two other isolates with almost identical ITS and D1/D2 sequences of the large subunit rRNA gene were isolated from the small intestine of cattle and a grease trap in Thailand. These isolates represent a novel species phylogenetically related to Wickerhamiella verensis, Wickerhamiella osmotolerans, Wickerhamiella tropicalis, Wickerhamiella sorbophila and Wickerhamiella infanticola. The novel species differs by 15-30 nucleotide differences from these species in the D1/D2 sequences. The name Wickerhamiella martinezcruziae f.a., sp. nov. is proposed. The holotype of Wickerhamiella martinezcruziae sp. nov. is CBS 16104T. The MycoBank number is MB 839328.
Asunto(s)
Filogenia , Saccharomycetales , Animales , Composición de Base , Brasil , Bovinos/microbiología , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Intestino Delgado/microbiología , Técnicas de Tipificación Micológica , Exudados de Plantas , ARN Ribosómico 16S/genética , Saccharomycetales/clasificación , Saccharomycetales/aislamiento & purificación , Arena/microbiología , Análisis de Secuencia de ADN , Tailandia , Clima TropicalRESUMEN
Microorganisms need to adapt to environmental changes, and genome plasticity can lead to rapid adaptation to hostile environments by increasing genetic diversity. Here, we investigate genome plasticity in the CTG(Ser1) yeast Scheffersomyces stipitis, an organism with an enormous potential for second-generation biofuel production. We demonstrate that S. stipitis has an intrinsically plastic genome and that different S. stipitis isolates have genomes with distinct chromosome organizations. Real-time evolution experiments show that S. stipitis genome plasticity is common and rapid since extensive genomic changes with fitness benefits are detected following in vitro evolution experiments. Hybrid MinION Nanopore and Illumina genome sequencing identify retrotransposons as major drivers of genome diversity. Indeed, the number and position of retrotransposons are different in different S. stipitis isolates, and retrotransposon-rich regions of the genome are sites of chromosome rearrangements. Our findings provide important insights into the adaptation strategies of the CTG(Ser1) yeast clade and have critical implications in the development of second-generation biofuels. These data highlight that genome plasticity is an essential factor for developing sustainable S. stipitis platforms for second-generation biofuels production. IMPORTANCE Genomes contain genes encoding the information needed to build the organism and allow it to grow and develop. Genomes are described as stable structures where genes have specific positions within a chromosome. Changes in gene dosage and position are viewed as harmful. However, it is becoming increasingly clear that genome plasticity can benefit microbial organisms that need to adapt rapidly to environmental changes. Mechanisms of genome plasticity are still poorly understood. This study focuses on Scheffersomyces stipitis, a yeast that holds great potential for second-generation biofuel production generated from forestry and agriculture waste. We demonstrate that S. stipitis chromosomes are easily reshuffled and that chromosome reshuffling is linked to adaptation to hostile environments. Genome sequencing demonstrates that mobile genetic elements, called transposons, mediate S. stipitis genome reshuffling. These data highlight that understanding genome plasticity is important for developing sustainable S. stipitis platforms for second-generation biofuels production.
Asunto(s)
Genoma Bacteriano , Plásticos , Saccharomycetales/genética , Biocombustibles , Fermentación , Fenotipo , Retroelementos , Saccharomycetales/clasificación , Saccharomycetales/aislamiento & purificación , Saccharomycetales/metabolismoRESUMEN
Six yeast isolates were obtained from rotting wood samples in Brazil and frass of a cerambycid beetle larva in French Guiana. Sequence analysis of the ITS-5.8S region and the D1/D2 domains of the large subunit rRNA gene showed that the isolates represent a novel species of Cyberlindnera. This novel species is related to Cyberlindnera japonica, Cyberlindnera xylosilytica, Candida easanensis and Candida maesa. It is heterothallic and produces asci with two or four hat-shaped ascospores. The name Cyberlindnera dasilvae sp. nov. is proposed to accommodate the novel species. The holotype of Cy. dasilvae is CBS 16129T and the designated paratype is CBS 16584. The MycoBank number is 838252. All isolates of Cy. dasilvae were able to convert xylose into xylitol with maximum xylitol production within 60 and 72 h. The isolates produced xylitol with values ranging from 12.61 to 31.79 g l-1 in yeast extract-peptone-xylose medium with 5% xylose. When the isolates were tested in sugarcane bagasse hydrolysate containing around 35-38 g l-1d-xylose, isolate UFMG-CM-Y519 showed maximum xylitol production.
Asunto(s)
Escarabajos/microbiología , Filogenia , Saccharomycetales/clasificación , Madera , Xilitol , Animales , ADN de Hongos/genética , ADN Espaciador Ribosómico , Heces/microbiología , Larva/microbiología , Técnicas de Tipificación Micológica , Saccharomycetales/aislamiento & purificación , Análisis de Secuencia de ADN , Madera/microbiología , Xilitol/metabolismoRESUMEN
INTRODUCTION: Fungemia in preterm infants results in high mortality and morbidity. The genotypes, drug susceptibilities of Candida pelliculosa strains, and clinical features of two outbreaks of neonatal candidemia caused by C. pelliculosa were analyzed, in order to provide evidence for the outbreaks and characteristics of C. pelliculosa neonatal candidemia. METHODOLOGY: The strains were genotyped by pulsed-field gel electrophoresis to investigate their genetic relatedness. The broth microdilution method was used to determine in vitro susceptibility of the isolates to antifungal drugs. Clinical features of the infected patients were collected to analyze the risks for C. pelliculosa infection. RESULTS: Fourteen neonates, hospitalized in the neonatal intensive care unit from November 2012 to October 2013, were infected by C. pelliculosa. All 14 patients were cured after treatment with fluconazole and discharged without any complications. The C. pelliculosa isolates from the 14 patients were clustered into two groups, indicating that the outbreaks were caused by two types of strains. Eight of nine strains isolated from the 2013 outbreak were clustered into the same group, while one isolate was grouped together with five isolates from the 2012 outbreak. In vitro experiments demonstrated high antifungal activity of fluconazole, voriconazole, amphotericin B, and 5-fluorocytosine to C. pelliculosa. The common symptoms of C. pelliculosa candidaemia were fever, cyanosis, polypnea, hypoactivity, and apnea. CONCLUSIONS: The current study revealed high in vitro susceptibility of C. pelliculosa to antifungals. As C. pelliculosa candidaemia cannot be characterized by clinical symptoms and routine blood testing alone, monitoring unusual strains isolated from immunodeficient hosts is very important to prevent possible outbreaks.
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Antifúngicos/farmacología , Candidemia/epidemiología , Brotes de Enfermedades , Recien Nacido Prematuro , Saccharomycetales/aislamiento & purificación , Antifúngicos/uso terapéutico , Candidemia/tratamiento farmacológico , Candidemia/microbiología , China/epidemiología , Células Clonales , Femenino , Edad Gestacional , Humanos , Recién Nacido , Unidades de Cuidado Intensivo Neonatal , Masculino , Pruebas de Sensibilidad Microbiana , Saccharomycetales/efectos de los fármacos , Saccharomycetales/genéticaRESUMEN
Osteomyelitis of the phalanx caused by Candida species are rare. A 49-year-old female patient was admitted to an external center with a splinter injury of the third phalanx of the middle finger of her left hand about 45 days ago. She was referred to our clinic with persistent pain and discharge, despite four-week antibiotherapy. Debridement and curettage were performed and partial excision of the distal phalanx at an appropriate level was done. Her complaints gradually resolved postoperatively with prescribed antibiotics for the pathogen identified as Candida lusitaniae based on the intraoperative cultures. At her three-month follow-up visit, treatment yielded near-excellent results. To the best of our knowledge, this is the first case of osteomyelitis of the distal phalanx caused by Candida lusitaniae in the literature, highlighting the importance of definitive diagnosis and pathogen-specific treatment, rather than empirical treatment, to achieve favorable results with cure.
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Falanges de los Dedos de la Mano/fisiopatología , Micosis/diagnóstico , Osteomielitis/diagnóstico , Saccharomycetales/aislamiento & purificación , Candidiasis/diagnóstico , Candidiasis/diagnóstico por imagen , Candidiasis/microbiología , Femenino , Humanos , Persona de Mediana Edad , Micosis/diagnóstico por imagen , Micosis/microbiología , Osteomielitis/diagnóstico por imagen , Osteomielitis/microbiología , TurquíaRESUMEN
BACKGROUND: Candida pelliculosa is an ecological fungal species that can cause infections in immunocompromised individuals. Numerous studies globally have shown that C. pelliculosa infects neonates. An outbreak recently occurred in our neonatal intensive care unit; therefore, we aimed to evaluate the risk factors in this hospital-acquired fungal infection. METHODS: We performed a case-control study, analysing the potential risk factors for neonatal infections of C. pelliculosa so that infection prevention and control could be implemented in our units. Isolated strains were tested for drug resistance and biofilm formation, important factors for fungal transmission that give rise to hospital-acquired infections. RESULTS: The use of three or more broad-spectrum antimicrobials or long hospital stays were associated with higher likelihoods of infection with C. pelliculosa. The fungus was not identified on the hands of healthcare workers or in the environment. All fungal isolates were susceptible to anti-fungal medications, and after anti-fungal treatment, all infected patients recovered. Strict infection prevention and control procedures efficiently suppressed infection transmission. Intact adhesin-encoding genes, shown by genome analysis, indicated possible routes for fungal transmission. CONCLUSIONS: The use of three or more broad-spectrum antimicrobials or a lengthy hospital stay is theoretically associated with the risk of infection with C. pelliculosa. Strains that we isolated are susceptible to anti-fungal medications, and these were eliminated by treating all patients with an antifungal. Transmission is likely via adhesion to the cell surface and biofilm formation.
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Biopelículas , Candidiasis/epidemiología , Candidiasis/prevención & control , Infección Hospitalaria/epidemiología , Infección Hospitalaria/prevención & control , Brotes de Enfermedades/prevención & control , Equipos y Suministros/microbiología , Unidades de Cuidado Intensivo Neonatal , Saccharomycetales/genética , Antifúngicos/uso terapéutico , Candidiasis/tratamiento farmacológico , Candidiasis/microbiología , Estudios de Casos y Controles , China/epidemiología , Infección Hospitalaria/tratamiento farmacológico , Infección Hospitalaria/microbiología , Femenino , Personal de Salud , Humanos , Recién Nacido , Control de Infecciones/métodos , Tiempo de Internación , Masculino , Pruebas de Sensibilidad Microbiana , ARN de Hongos/genética , Factores de Riesgo , Saccharomycetales/aislamiento & purificaciónRESUMEN
Tibetan kefir grains (TKG) are multi-functional starter cultures used in foods and have been applied in various fermentation systems. This study aimed to investigate the microbial community composition of TKG, the detoxification abilities of TKG and their isolates towards common mycotoxins, and the potential for applying TKG and their associated microbial populations to avoid mycotoxin contamination in dairy products. Cultivation-independent high-throughput sequencing of bacterial and fungal rDNA genes indicated that Lactobacillus kefiranofaciens and Kazachstania turicensis were the most abundant bacterial and fungal taxa, respectively. In addition, 27 total isolates were obtained using cultivation methods. TKG removed more than 90% of the Ochratoxin A (OTA) after 24 h, while the isolate Kazachstania unisporus AC-2 exhibited the highest removal capacity (~46.1%). Further, the isolate exhibited good resistance to acid and bile salts environment. Analysis of the OTA detoxification mechanism revealed that both adsorption and degradation activities were exhibited by TKG, with adsorption playing a major detoxification role. Furthermore, the addition of OTA did not affect the microbial community structure of TKG. These results indicate that TKG-fermented products can naturally remove mycotoxin contamination of milk and could potentially be practically applied as probiotics in fermentation products.
Asunto(s)
Kéfir/microbiología , Microbiota , Ocratoxinas/metabolismo , Animales , Biotransformación , Bovinos , Fermentación , Lactobacillus/clasificación , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Lactobacillus/metabolismo , Leche/microbiología , Ocratoxinas/análisis , Saccharomycetales/clasificación , Saccharomycetales/genética , Saccharomycetales/aislamiento & purificación , Saccharomycetales/metabolismo , TibetRESUMEN
During an investigation of the yeast communities associated with wild fruit shrubs in Dagestan (Caucasus, Russia), four fermenting ascospore-producing yeast strains were isolated from leaves of the Georgian honeysuckle (Lonicera iberica M. Bieb.) and from soil underneath this plant. Phylogenetic analyses based on concatenated sequences of the ITS region and D1/D2 domains of the large subunit rRNA gene and concatenated sequences of the ribosomal DNA cystron, RPB2 and TEF1 genes showed that the isolated strains represented a new species of the genus Zygotorulaspora. The new species was placed in the basal position to other species of the clade and close to Zygotorulaspora mrakii. Based on the results of phylogenetic analyses and the phenotypic characteristics of the four studied strains, a novel species is described, for which the name Zygotorulaspora dagestanica sp. nov. is proposed. The holotype is KBP Y-4591T, three metabolically inactive cryopreserved isotype cultures are DSM 100088, VKM Y-3060 and VKPM Y-4318. The MycoBank number is MB 838285.