-
Indian Journal of Medical Microbiology 2023Cryptococcosis is one of the most significant systemic fungal infections worldwide. Epidemiological data for pediatric cryptococcosis is very limited. Therefore, we... (Review)
Review
PURPOSE
Cryptococcosis is one of the most significant systemic fungal infections worldwide. Epidemiological data for pediatric cryptococcosis is very limited. Therefore, we planned this study to determine the burden of cryptococcosis in the pediatric population at our tertiary care center and performed review of literature.
MATERIAL AND METHODS
In this retrospective study, all the patients less than 18 years of age were diagnosed with cryptococcosis, from January 2015-June 2021 were included. Demographic, clinical, and laboratory details of all the patients were noted. Furthermore, PubMed and MedLine databases were comprehensively searched for cases of pediatric cryptococcosis till June 2021.
RESULTS
Of the total 5420 samples from suspected cryptococcosis cases processed at mycology laboratory, a total of 21 episodes of cryptococcosis (0.39%) were identified in 15 pediatric patients. The majority of the patients were apparently immunocompetent (10/15). Central nervous system (CNS) cryptococcosis was the most common presentation, followed by disseminated disease. All the isolates were identified as Cryptococcus neoformans (formerly referred to as C. neoformans var grubii), except one that was identified as Papiliotrema laurentii (formerly referred to as Cryptococcus laurentii). A standard treatment regimen inclusive of induction and maintenance therapy was provided in only five patients. The literature review revealed a total of 125 studies describing 1134 cases, of which 76.4% are reported from outside Asia, the majority (65.7%) restricted to CNS with C. neoformans as the commonest species. The management profile divulged a significantly higher use of standard drug regimen in Asia as compared to the rest of the world. Mortality of 13.32% was noted worldwide.
CONCLUSION
To the best of our knowledge, this is the first clinico-epidemiological study of pediatric cryptococcosis from India and the largest retrospective study worldwide. The rising incidence among immunocompetent individuals, especially in Asia, is a matter of concern. Clinical suspicion and early diagnosis are the cornerstones for the management of cases.
Topics: Humans; Child; Tertiary Care Centers; Retrospective Studies; Cryptococcosis; Cryptococcus neoformans; Asia
PubMed: 36464534
DOI: 10.1016/j.ijmmb.2022.11.002 -
Applied Microbiology and Biotechnology Nov 2022Papiliotrema laurentii, previously classified as Cryptococcus laurentii, is an oleaginous yeast that has been isolated from soil, plants, and agricultural and industrial... (Review)
Review
Papiliotrema laurentii, previously classified as Cryptococcus laurentii, is an oleaginous yeast that has been isolated from soil, plants, and agricultural and industrial residues. This variety of habitats reflects the diversity of carbon sources that it can metabolize, including monosaccharides, oligosaccharides, glycerol, organic acids, and oils. Compared to other oleaginous yeasts, such as Yarrowia lipolytica and Rhodotorula toruloides, there is little information regarding its genetic and physiological characteristics. From a biotechnological point of view, P. laurentii can produce surfactants, enzymes, and high concentrations of lipids, which can be used as feedstock for fatty acid-derived products. Moreover, it can be applied for the biocontrol of phytopathogenic fungi, contributing to quality maintenance in post- and pre-harvest fruits. It can also improve mycorrhizal colonization, nitrogen nutrition, and plant growth. P. laurentii is also capable of degrading polyester and diesel derivatives and acting in the bioremediation of heavy metals. In this review, we present the current knowledge about the basic and applied aspects of P. laurentii, underscoring its biotechnological potential and future perspectives. KEY POINTS: • The physiological characteristics of P. laurentii confer a wide range of biotechnological applications. • The regulation of the acetyl-CoA carboxylase in P. laurentii is different from most other oleaginous yeasts. • The GEM is a valuable tool to guide the construction of engineered P. laurentii strains with improved features for bio-based products.
Topics: Acetyl-CoA Carboxylase; Glycerol; Yarrowia; Fatty Acids; Nitrogen; Carbon; Oils; Soil; Monosaccharides; Surface-Active Agents; Polyesters
PubMed: 36197457
DOI: 10.1007/s00253-022-12208-2 -
Journal of Fungi (Basel, Switzerland) Jun 2022Icariin is the most effective bioactive compound in Herba Epimedii. To enhance the content of icariin in the epimedium water extract, a novel strain, ZJU-L07, producing...
Icariin is the most effective bioactive compound in Herba Epimedii. To enhance the content of icariin in the epimedium water extract, a novel strain, ZJU-L07, producing an intracellular α-L-rhamnosidase was isolated from the soil and mutagenized. The specific activity of α-L-rhamnosidase was 29.89 U·mg through purification, and the molecular mass of the enzyme was 100 kDa, as assayed by SDS-PAGE. The characterization of the purified enzyme was determined. The optimal temperature and pH were 55 °C and 7.0, respectively. The enzyme was stable in the pH range 5.5-9.0 for 2 h over 80% and the temperature range 30-40 °C for 2 h more than 70%. The enzyme activity was inhibited by Ca, Fe, Cu, and Mg, especially Fe. The kinetic parameters of and were 1.38 mM and 24.64 μmol·mg·min using pNPR as the substrate, respectively. When epimedin C was used as a nature substrate to determine the kinetic parameters of α-L-rhamnosidase, the values of and were 3.28 mM and 0.01 μmol·mg·min, respectively. The conditions of enzymatic hydrolysis were optimized through single factor experiments and response surface methodology. The icariin yield increased from 61% to over 83% after optimization. The enzymatic hydrolysis method could be used for the industrialized production of icariin. At the same time, this enzyme could also cleave the α-1,2 glycosidic linkage between glucoside and rhamnoside in naringin and neohesperidin, which could be applicable in other biotechnological processes.
PubMed: 35736128
DOI: 10.3390/jof8060644 -
International Journal of Biological... Jul 2022Alginates are widely used polysaccharides for biomaterials engineering, which functional properties depend on guluronic and mannuronic acid as the building blocks. In...
Alginates are widely used polysaccharides for biomaterials engineering, which functional properties depend on guluronic and mannuronic acid as the building blocks. In this study, enzymatically crosslinked hydrogels based on sodium alginate (Na-Alg) and the exopolysaccharide (EPS) derived from Cryptococcus laurentii 70766 with glucuronic acid residues were synthesized and characterized as a new potential source of polysaccharide for biomaterials engineering. The EPS was extracted (1.05 ± 0.57 g/L) through ethanol precipitation. Then the EPS and Na-Alg were functionalized with tyramine hydrochloride to produce enzymatically crosslinked hydrogels in the presence of horseradish peroxidase (HRP) and HO. Major characteristics of the hydrogels such as gelling time, swelling ratio, rheology, cell viability, and biodegradability were studied. The swelling ratio and degradation profile of both hydrogels showed negative values, indicating an increased crosslinking degree and a lower water uptake percentage. The EPS hydrogel showed similar gelation kinetics compared to the Alg hydrogel. The EPS and its hydrogel were found cytocompatible. The results indicate the potential of EPS from C. laurentii 70766 for biomedical engineering due to its biocompatibility and degradability. Further studies are needed to confirm this EPS as an alternative for Alg in tissue engineering applications, particularly in the development of wound dressing products.
Topics: Alginates; Basidiomycota; Biocompatible Materials; Hydrogels; Hydrogen Peroxide; Ions; Tissue Engineering
PubMed: 35613678
DOI: 10.1016/j.ijbiomac.2022.05.133 -
PloS One 2022Neuromeningeal cryptococcosis (NMC) is a life-threatening opportunistic infection in advanced HIV disease patients (AHDP). It is caused by Cryptococcus spp. complexes...
Neuromeningeal cryptococcosis (NMC) is a life-threatening opportunistic infection in advanced HIV disease patients (AHDP). It is caused by Cryptococcus spp. complexes and mainly occurs in sub-Saharan Africa. In this study, we performed molecular characterization and antifungal susceptibility profiling of Cryptococcus isolates from AHDP in Kinshasa (DRC). Additionally, we investigated a possible association between NMC severity factors and the Cryptococcus neoformans (Cn) multilocus sequence typing (MLST) profiles. We characterized the isolates using PCR serotyping, MALDI-TOF MS, internal transcribed spacer (ITS) sequencing, and MLST. Susceptibility testing for the major antifungal drugs was performed according to the EUCAST guidelines. Parameters associated with NMC severity, such as hypoglycorrhachia (< 50 mg/dL), increased cerebral spinal fluid opening pressure (> 30 cm H2O), and poor therapeutic outcome were compared with the Cn MLST sequences type (ST). Twenty-three out of 29 Cryptococcus isolates were identified as serotype A using PCR serotyping (79.3%; 95% IC: 65.5-93.1), while six (20.7%; 95% IC: 6.9-34.5) were not serotypable. The 29 isolates were identified by ITS sequencing as follows: Cryptococcus neoformans (23/29, 79.3%), Cutaneotrichosporon curvatus (previously called Cryptococcus curvatus) (5/29, 17.2%), and Papiliotrema laurentii (Cryptococcus laurentii) (1/29, 3.5%). Using the ISHAM MLST scheme, all Cn isolates were identified as molecular type VNI. These comprised seven different STs: ST93 (n = 15), ST5 (n = 2), ST53 (n = 1), ST31 (n = 1), ST4 (n = 1), ST69 (n = 1), and one novel ST that has not yet been reported from other parts of the world and was subsequently assigned as ST659 (n = 2). Of the included strains, only Papiliotrema laurentii was resistant to amphoterin B (1/29, 3.5%), 6.8% (2/29) were resistant to 5-flucytosine (the single Papiliotrema laurentii strain and one Cryptococcus neoformans isolate), and 13.8% (4/29) to fluconazole, including two of five (40%) Cutaneotrichosporon curvatus and two of 23 (8.7%) C. neoformans strains. We found a significative association between poor therapeutic outcome and a non-ST93 sequence type of causative strains (these concerned the less common sequence types: ST53, ST31, ST5, ST4, ST659, and ST69) (87.5% versus 40%, p = 0.02). Molecular analysis of Cryptococcus spp. isolates showed a wide species diversity and genetic heterogenicity of Cn within the VNI molecular type. Furthermore, it is worrying that among included strains we found resistances to several of the commonly used antifungals.
Topics: Antifungal Agents; Basidiomycota; Cryptococcosis; Cryptococcus neoformans; Democratic Republic of the Congo; Genetic Variation; Genotype; HIV Infections; Humans; Multilocus Sequence Typing; Mycological Typing Techniques
PubMed: 35587939
DOI: 10.1371/journal.pone.0267842 -
BMJ Case Reports May 2022A man in mid-50s presented with progressive blurred vision in his left eye for over 6 weeks. He was a known diabetic with history of COVID-19 pneumonia treated with...
A man in mid-50s presented with progressive blurred vision in his left eye for over 6 weeks. He was a known diabetic with history of COVID-19 pneumonia treated with steroids and remdesivir. He had pyelonephritis and urinary culture grown He was referred as a case of non-resolving vitreous haemorrhage. Visual acuity (VA) was hand movements with fundus showing dense vitritis. He underwent pars plana vitrectomy, vitreous biopsy with intraocular antibiotics (imipenem) suspecting as a case of endogenous bacterial endophthalmitis. Vitreous biopsy did not yield organisms on the smear/culture. The patient's condition worsened with perception of light and fundus showing dense vitritis with discrete yellowish white deposits on the surface of the retina. A repeat vitreous biopsy done along with intravitreal injection of voriconazole (suspecting fungal aetiology) grown fungal colonies and the organism was identified as At 4-month follow-up, the VA improved to 6/24.
Topics: Anti-Bacterial Agents; Basidiomycota; COVID-19; Endophthalmitis; Eye Infections, Bacterial; Humans; Male; Retrospective Studies; Vitrectomy
PubMed: 35545307
DOI: 10.1136/bcr-2021-246637 -
G3 (Bethesda, Md.) Dec 2021Papiliotrema terrestris strain LS28 is a biocontrol agent selected for its antagonistic activity against several plant pathogens both in the field and postharvest. The...
Papiliotrema terrestris strain LS28 is a biocontrol agent selected for its antagonistic activity against several plant pathogens both in the field and postharvest. The availability of a genome sequencing sets the foundation for the identification of the genetic mechanisms of its antagonistic activity. The genome size is 21.29 Mbp with a G+C content of 58.65%, and genome annotation predicts 8,626 protein-encoding genes. Phylogenetic analysis based on whole-genome data confirms that P. terrestris is a Tremellomycetes more closely related to Papiliotrema flavescens than Papiliotrema laurentii.
Topics: Basidiomycota; High-Throughput Nucleotide Sequencing; Phylogeny; Saccharomyces cerevisiae; Sequence Analysis, DNA
PubMed: 34534326
DOI: 10.1093/g3journal/jkab332 -
Frontiers in Cellular and Infection... 2021Cryptococcosis is an infectious disease of worldwide distribution, caused by encapsulated yeasts belonging to the phylum Basidiomycota. The genus includes several...
Cryptococcosis is an infectious disease of worldwide distribution, caused by encapsulated yeasts belonging to the phylum Basidiomycota. The genus includes several species distributed around the world. The / species complex is largely responsible for most cases of cryptococcosis. However, clinical series have been published of infections caused by () and (), among other related genera. Here, we examined the pathogenic potential and antifungal susceptibility of / species complex (clades I and II) and related genera ( and ) isolated from environmental and clinical samples. . (clade III), . (clade IV) and /. (clade V) strains produced higher levels of phospholipase and hemolysins, whereas the / species complex strains (clades I and II) had markedly thicker capsules, produced more biofilm biomass and melanin, which are known virulence attributes. Interestingly, 40% of . strains (clade II) had MICs above the ECV established for this species to amphotericin B. Several non-/ species complex (clades III to V) had MICs equal to or above the ECVs established for and for all the three antifungal drugs tested. Finally, all the non- clinical isolates (clades III to V) produced more melanin than the environmental isolates might reflect their particularly enhanced need for melanin during protection. It is very clear that / species complex (clades I and II) strains, in general, show more similar virulence phenotypes between each other when compared to non-/ species complex (clades III to V) isolates. These observations together with the fact that . and spp. (clades III to V) strains were collected from the outside of a University Hospital, identify features of these yeasts important for environmental and patient colonization and furthermore, define mechanisms for infections with these uncommon pathogens.
Topics: Antifungal Agents; Basidiomycota; Cryptococcus gattii; Cryptococcus neoformans; Humans; Virulence; Virulence Factors
PubMed: 34277464
DOI: 10.3389/fcimb.2021.642658 -
Journal de Mycologie Medicale Jun 2021Papiliotrema laurentii (formerly Cryptococcus laurentii) and Papiliotrema albidus (formerly Cryptococcus albidus) are yeast-like environmental fungi which are largely...
Papiliotrema laurentii (formerly Cryptococcus laurentii) and Papiliotrema albidus (formerly Cryptococcus albidus) are yeast-like environmental fungi which are largely considered as non-pathogenic to humans. However, invasive infections caused by P. laurentii have recently been reported in some patients with an impaired immune system. Here, we describe the first case of P. laurentii fungemia in a premature, very low-birth-weight neonate in Kuwait and the Middle East. Repeated bloodstream isolates were obtained and were tentatively identified as P. laurentii by Vitek 2 yeast identification system. The identification of the yeast isolates as P. laurentii was confirmed by PCR-sequencing of ribosomal DNA (rDNA). Antifungal susceptibility testing data showed that the isolates were susceptible to amphotericin B, fluconazole and voriconazole but appeared resistant to caspofungin. The baby was successfully treated with liposomal amphotericin B.
Topics: Adult; Amphotericin B; Antifungal Agents; Basidiomycota; DNA, Ribosomal; Female; Fungemia; Humans; Infant, Low Birth Weight; Infant, Newborn; Kuwait; Male; Mycological Typing Techniques; Treatment Outcome
PubMed: 33639444
DOI: 10.1016/j.mycmed.2021.101123 -
Archives of Microbiology Apr 2021This study aimed to identify the yeast strains associated with the tree bark samples collected from the Aegean and Marmara regions and from rotten fruit samples....
This study aimed to identify the yeast strains associated with the tree bark samples collected from the Aegean and Marmara regions and from rotten fruit samples. Fifty-one yeast strains were successfully isolated and screened for their abilities to produce industrially important extracellular enzymes. Thirty isolates demonstrated ability to produce at least two different enzymes and were selected for subsequent molecular identification using sequence analysis of ITS region and D1/D2 domain of the 26S rDNA. The most prevalent strains belonged to Papiliotrema laurentii (%23), Papiliotrema terrestris (%13) and Candida membranifaciens (%10). Papiliotrema laurentii and Papiliotrema terrestris recorded the highest enzymatic activities for all the screened enzymes. To the best of our knowledge, this is the first report that identifies the yeast strains associated with the tree barks of Turkey and among the limited comprehensive studies that screened considerable number of isolates for their ability to produce several industrially important enzymes.
Topics: DNA, Fungal; Fruit; Industrial Microbiology; Molecular Typing; Plant Bark; RNA, Ribosomal; Turkey; Yeasts
PubMed: 33156373
DOI: 10.1007/s00203-020-02104-6