Cryptococcus Gatti Research Articles

P063 Research on antifungal activity of a new azoles compound, YZJT-1903

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PM ObjectivesFluconazole is widely used to treat invasive fungal infections, but the fluconazole resistance of pathogenic fungi undermines its antifungal efficacy. Although voriconazole has a good anti-Aspergillus fumigatus activity, it is not a first-line drug for treating infections caused by Candida and Cryptococcus species. To meet the demand for new azoles, in our previous studies, we identified a new azoles compound, YZJT-1903 (Fig. 1e), and found that YZJT-1903 has a longer in vivo half-life (˃10 days in rat) and a wider therapeutic window than voriconazole, indicating that YZJT-1903 is a promising azoles compound to treat invasive fungal infections. In this study, we further investigated antifungal activity of YZJT-1903 compared with fluconazole and voriconazole.MethodsWe investigated the antifungal spectrum of YZJT-1903 and minimum inhibitory concentration (MIC) and accumulative antifungal percentage of YZJT-1903 against various pathogenic fungi using microbroth dilution method. We quantitatively analyzed the inhibitory effect of YZJT-1903 on fungal growth by the Time-Growth Curve assay. Mutation Preventative Concentration (MPC) was carried out to verify the antifungal potential of YZJT-1903. Sterols of plasma membrane were extracted and the composition was analyzed through Gas Chromatograph-Mass Spectrometer (GC-MS) to verify the classical action mechanism of azoles.ResultsOur MIC assay results demonstrated that YZJT-1903 has a broad antifungal spectrum and can significantly inhibit the growth of A. fumigatus, Cryptococcus neoformans, Cryptococcus gatti, and Candida species (such as Candida albicans, C. tropicalis, C. parapsilosis, C. glabrata, C. guilliermondii, and C. auris) (Fig. 1a). We found that the antifungal activity of YZJT-1903 is equivalent to that of voriconazole, but superior to that of fluconazole (Fig. 1a). Accumulative antifungal percentage can directly reflect this relationship quantitatively among YZJT-1903, fluconazole, and voriconazole due to the curve of YZJT-1903 has no significance with voriconazole (Fig. 1b). YZJT-1903 (0.25 μg/ml) has similar inhibitory effect to voriconazole (0.25 μg/ml) on the growth of C. albicans and C. neoformans, but has the best inhibitory effect on C. auris [compared with voriconazole (0.25 μg/ml), and fluconazole (0.25 μg/ml)] (Fig. 1c). MPC of YZJT-1903 in C. neoformans is as low as 0.25 μg/ml which means YZJT-1903 at low concentration can already prevent the drug-resistant mutation of strains, therefore, avoid the occurrence of resistance in Cryptococcus spp. (Fig. 1d). Extraction of sterols showed that the fungal cell treated with YZJT-1903 at 0.063 μg/ml have completely no detectable ergosterol which is similar to the group of fluconazole at 4 μg/ml, and the group of voriconazole at 0.031 μg/ml (Fig. 2). This result gave a hint that maybe the property of YZJT-1903 is more similar to voriconazole which may matter with the structure of these two compounds. We found that feeding exogenous 100 μm ergosterol counteracted the antifungal activity of YZJT-1903, indicating that YZJT-1903 has an antifungal activity by inhibiting the synthesis of ergosterol.ConclusionOur study demonstrates that YZJT-1903 has a potent antifungal activity, which will contribute to addressing devastating global invasive fungal infections caused by Candida and Cryptococcus species.

Primary Cutaneous Cryptococcosis Caused by Cryptococcus gatti in an Elderly Patient

According to the spread of Cryptococcus sp., fungal infections can be classified as primary or secondary. In primary cutaneous cryptococcosis, the fungi are restricted to the skin of the patients, without systemic involvement. The incidence of primary cutaneous cryptococcosis is high in patients with immunosuppression, and this type of infection is rarely observed in patients who are immunocompetent. In the present case report, a patient who is immunocompetent and has systemic comorbidity reported that, after skin trauma, ulcerovegetative lesions appeared in the right upper arm; the etiologic agent was identified as Cryptococcus gatti, serotype B. The cutaneous lesions healed completely after 5 months of fluconazole treatment.

Mass doesn’t mean malignancy – A rare presentation due to Cryptococcus gatti

Mass doesn’t mean malignancy – A rare presentation due to Cryptococcus gatti

Melphalan-Based Regimen Is a Safe and Effective Conditioning Regimen Prior to Allogeneic Hematopoietic Cell Transplantation in Older Adults (≥70 years) with Hematological Malignancies

With the adoption of reduced-intensity conditioning (RIC) regimen, allogeneic hematopoietic cell transplantation (alloHCT) is being increasingly used in older adults. However, data are sparse on the safety and efficacy of this procedure in patients aged ≥70 years. Currently the majority of these patients receive either non-myeloablative busulfan (Bu; 3.2-6.4mg/kg) or low-dose total body irradiation (TBI; 2-4.5Gy)- based conditioning regimens, which are associated with a relatively high incidence of disease relapse.We report here the transplant outcomes of patients aged ≥70 years with hematological malignancies who underwent alloHCT with melphalan (Mel)-based conditioning regimen (Mel 100-140mg/m2 plus fludarabine or clofarabine) between May 2007 and September 2016 at City of Hope. We evaluated 53 consecutive patients (median: 71, range: 70-78 years, 35 males and18 females) who underwent AlloHCT for acute myeloid leukemia (n=27), myelodysplastic syndrome (n=14), myeloproliferative neoplasm (n=6), acute lymphoblastic leukemia (n=2), non-Hodgkin lymphoma (n=2), blastic plasmacytoid dendritic cell neoplasm (n=1), or acute promyelocytic leukemia (n=1) from HLA-identical sibling (n=11), matched unrelated donor (8/8, n=38) or mismatched unrelated donor (n=4). Fifty-one patients received peripheral blood stem cell grafts while two received bone marrow grafts. Graft versus host disease (GVHD) prophylaxis was tacrolimus/sirolimus-based in all patients. The disease risk index (DRI) score was high-very high in 36% of patient (n=19) and Karnofsky score was ≥70% in all patients. The HCT comorbidity index was 3 or more in 21 patients.Fifty-two of our 53 patients achieved neutrophil engraftment with the median time to engraft of 15 days (range: 11-29 days). Blood or bone marrow chimerism analyses showed >95% of patients achieved >95% donor chimerism within 6 weeks from alloHCT, consistent with “semi-ablative” nature of Mel-based RIC. With a median follow up of 22 months (range: 5-99 months), the 2-year overall survival (OS) and progression-free survival (PFS) were 65.8% (95%CI: 49.9-77.7%) and 60.7% (95%CI: 45.2-73.0%), respectively (Figure 1a). Cumulative Incidence (CI) of non-relapse mortality (NRM) at 1 and 2 years were 18% and 18%, and CI of relapse at 1- and 2-years were18.6% and 21.3%, respectively (Figure 1b). 100-day CI of grade II-IV acute GVHD was 37.7% (grade III-IV: 18.9%), and 2-year CI of chronic GVHD was 57% (48% extensive). In multivariate high/very high DRI was the only independent predictor for poor OS was (HR: 3.14, 95%CI: 1.29-7.61, p=0.011).While clinical outcomes were favorable for the most part, the hospital course was complicated by ICU transfer (24.5%, n=13) and altered mental status or fall requiring CT scan of the brain (24.5%, n=13), with the median duration of hospitalization of 33 days (range: 20-147 days). Blood stream infection (BSI) was developed in 11 patients (21%). Only 2 patients (3.8%) developed probable/proven invasive fungal infection (one patient developed Aspergillus fumigatus and the other patient developed Cryptococcus gatti). While CMV viremia was observed in 13 patients (24.5%) no CMV disease was diagnosed in any of these patients. Of the 49 discharged patients, 48 went home (one to rehab facility).In conclusion, alloHCT in combination with Mel-based semi-ablative conditioning is associated with acceptable toxicities including NRM, low-risk of relapse, favorable OS and relapse free survival (RFS) in patients ages 70 years and older. Our data collectively suggest that chronological age alone should not exclude patients from undergoing alloHCT, and this treatment should be offered to selected older individuals with hematologic malignancies. [Display omitted] DisclosuresNademanee:seattle Genetics: Speakers Bureau. Stein:Stemline: Consultancy; Amgen: Consultancy, Speakers Bureau.

Aristolochia triangularis Cham. Stems and Leaves’ Essential Oils and their Antimicrobial and Antimycobacterial Effects

Background: Aristolochia triangularis Cham., popularly known as the "cipó-milhomens", "angelicó" and "ypê-mi", is applied for the treatment of wounds, skin diseases (6,7), digestive and circulatory system diseases as an antipyretic and for malaria fever also. Objective: In this work, we investigated the chemical composition, the antimicrobial and antimycobacterial activities of the Essential Oils (EOs) extracted from A. triangularis fresh stems and leaves collected in Southern Brazil. Methods: Fresh stems and fresh leaves of Aristolochia triangularis Cham. were separately subjected to hydrodistillation using a Clevenger-type apparatus. The chemical composition of the Essential Oils (EOs) was analyzed by Gas Chromatography/Mass Spectrometry (GC/MS). The oil samples were evaluated for their antimycobacterial, antibacterial and antifungal activities against twenty-four microorganisms. Results: Hydrodistillation of fresh stems and leaves of A. triangularis resulted in 0.16% (w/w) and 0.37% (w/w) of light-yellow oils, respectively. Germacrene D was found in 13.2 - 13.5% in both the EOs. The constituent most abundant in the stems EO (19.18%) was the oxygenated diterpene ent- Kaur-16-en-19-al (10), along with E-nerolidol (17.89%). The main constituents of the leaves EO were bicyclogermacrene (24.79%), β-elemene (11.30%), E-caryophyllene (10.40%) and germacrene A (9.42%), in addition to the previously mentioned germacrene D. The stems and leaves EOs showed capacity to inhibit the Gram-negative Enterobacter aerogenes and the stems EO showed the capacity to inhibit Staphylococcus aureus, with MIC values of 31.2 μg/mL. S. aureus was found to be moderately sensitive to leaves EO, while stems EO displayed moderate activity against Enterococcus faecalis and Salmonella typhimurium (MIC values of 62.5 μg/mL). Candida glabrata was highly susceptible to both EOs (MIC values < 3.9 μg/mL). The EOs showed moderate potential to inhibit the growth of Cryptococcus gatti and Cryptococcus neoformans (MICs of 62.5 μg/mL). Conclusion: The A. triangularis essential oils from stems and leaves displayed the capacity to inhibit Enterobacter aerogenes (MIC values of 31.2 μg/mL) and high antifungal effect against Candida glabrata (MIC values of <3.9 μg/mL). Mycobacterium massiliense and M. abscessus were susceptible to the leaves EO, with MICs of 39.06 μg/mL. These results showed the potential of A. triangularis essential oils as antifungal and antimycobacterial agents to be used in the development of new antibiotics.

Codon usage signatures in the genus Cryptococcus: A complex interplay of gene expression, translational selection and compositional bias

The fungal genus Cryptococcus comprises of several diverse species. The pathogens forming Cryptococcus neoformans/ Cryptococcus gatti species complex are of immense clinical significance owing to the high frequency of infections and deaths globally. Three closely related non-pathogenic species namely, Cryptococcus amylolentus, Cryptococcus wingfieldii and Cryptococcus depauperatus are the non-pathogenic ancestral species from which pathogenic lineages have diverged. In the current study, a comprehensive analysis of factors influencing the codon and amino acid usage bias in six pathogenic and three non-pathogenic species was performed. Our results revealed that though compositional bias played a crucial role, translational selection and gene expression were the key determinants of codon usage variations. Analysis of relative dinucleotide abundance and codon context signatures revealed strict avoidance of TpA dinucleotide across genomes. Multivariate statistical analysis based on codon usage data resulted in discrete clustering of pathogens and non-pathogens which correlated with previous reports on their phylogenetic distribution.

Case report – meningitic symptoms in immunocompetent patient: an unusual case of cryptococcus gatti infection

Case report – meningitic symptoms in immunocompetent patient: an unusual case of cryptococcus gatti infection

Synthesis of Superparamagnetic Iron Oxide Nanoparticles Stabilized by Biocompatible Supramolecular β-Cyclodextrin for Biomedical Applications

Superparamagnetic iron oxide nanoparticles have always been a topic of significance in biomedical research due to their tremendous range of applications. The present study reports the synthesis of superparamagnetic Fe2O3 nanoparticles by a simple NaBH4-reduction, stabilised by supramolecular inclusion host β-cyclodextrin. The crystallite size was calculated from X-ray diffraction studies using Debye Scherrer equation and found to be in the range 14-23 nm. The antibacterial activity of the sample was studied against Vibrio cholerae and Clostridium botulinum using disc diffusion method. Antifungal activity was monitored against three fungal strains Candida auris, Trichophyton rubrum and Cryptococcus gatti using well diffusion method.

Cryptococcus gatti Infection With Pulmonary and CNS Involvement in an Immunocompetent Patient

Cryptococcus gatti Infection With Pulmonary and CNS Involvement in an Immunocompetent Patient

Essential Oil Composition, Antimicrobial and Pharmacological Activities of Lippia sidoides Cham. (Verbenaceae) From São Gonçalo do Abaeté, Minas Gerais, Brazil.

Background:Lippia sidoides (Verbenaceae) is used in Brazilian folk medicine as an antiseptic, and it is usually applied topically on skin, mucous membranes, mouth, and throat, or used for vaginal washings.Objectives:To analyze the chemical composition of the essential oil from L. sidoides collected in São Gonçalo do Abaeté, Minas Gerais and grown in Hidrolândia, Goiás; to evaluate the antimicrobial activity of the essential oil, crude ethanol extract, and hexane, dichloromethane, ethyl-acetate, and aqueous fractions (AFs); to study the antinociceptive, anti-inflammatory, and central nervous system activities of the crude ethanol extract.Materials and methods:The essential oils were obtained by hydro-distillation using a Clevenger-type apparatus and analyzed by GC/MS. The antimicrobial activity in vitro was performed by broth microdilution method. The pharmacological tests were performed using female Swiss albino mice.Results:The major components of the essential oil were isoborneol (14.66%), bornyl acetate (11.86%), α-humulene (11.23%), α-fenchene (9.32%), and 1.8-cineole (7.05%), supporting the existence of two chemotypes of this species. The hexane fraction (HF) had good antifungal activity against Cryptococcus sp. ATCC D (MIC = 31.25 μg/mL) and Cryptococcus gatti L48 (MIC = 62.5 μg/mL). In the pharmacological tests, the crude ethanol extract presented antinociceptive and anti-inflammatory activities.Conclusion:Given that the ethanol extract of L. sidoides is included in the Formulary of Phytotherapeutic Agents of the Brazilian Pharmacopeia as an anti-inflammatory for oral cavities, the present work provides scientific evidence to back this use and highlight the importance of selecting the appropriate chemotype on the basis of the expected biological response.SUMMARYThe major components of the essential oil of L. sidoides were isoborneol bornyl acetate, α-humulene, α-fenchene, and 1.8-cineole. The HF had good antifungal activity against Cryptococcus sp. ATCC D and C. gatti L4.The crude ethanol extract of L. sidoides presented antinociceptive and anti-inflammatory activities.The present work provides scientific evidence of the importance of selecting the appropriate chemotype on the basis of the expected biological response. Abbreviations used: UFG: Universidade Federal de Goiás; HF: hexane fraction; DF: dichloromethane fraction; EAF: ethyl acetate fraction; AF: aqueous fraction; MeOH: methanol; MIC: minimum inhibitory concentration; ATCC: American Type Culture Collection; MH: Müller Hinton; DMSO: dimethyl sulfoxide; RPMI: Roswell Park Memorial Institute; NaCl: sodium chloride; μL: microliters; mL: milliliters; μg: microgram; kg: kilogram; h: hour; min: minute; cm: centimeter; COBEA: Brazilian College of Animal Experiments; p.o.:, oral; i.p.: intraperitoneal; s.c.: subcutaneous; SEM: standard error of the mean; RI: retention indices.

Cryptococcus: Shedding New Light on an Inveterate Yeast.

Cryptococcus has emerged as a significant pathogen in immunocompromised patients. While the diagnostic testing and the antifungal treatment of cryptococcal infections have become firmly established in clinical practice, new developments and areas of ambiguity merit further consideration. These include the potential for donor transmission of Cryptococcus; cirrhosis-associated cryptococcosis, particularly during transplant candidacy; the utility of serum cryptococcal antigen testing of asymptomatic individuals in high-prevalence, poor-resource areas; pathogenesis and treatment of the immune reconstitution syndrome, specifically in relation to antiretroviral therapy and immunosuppressive medications; and new challenges posed by the emerging species of Cryptococcus gatti. In this article, we summarize the literature pertaining to these topics, focusing on recent progress.

Population genomic analyses reveal possible drivers of population divergence.

Recent advances in sequencing technology and efficiency enable new and improved methods to investigate how populations diverge and species evolve. Fungi have relatively small and simple genomes and can often be cultured in the laboratory. Fungal populations can thus be sequenced for a relatively low cost, which makes them ideal for population genomic analyses. In several recent population genomic studies, wild populations of fungal model organisms and human pathogens have been analysed, for example Neurospora crassa (Ellison etal. ), Saccharomyces uvarum (Almeida etal. ), Coccidioides spp. (Neafsey etal. ) and Cryptococcus gatti (Engelthaler etal. ). In this issue of Molecular Ecology, Branco etal. () apply population genomic tools to understand population divergence and adaptation in a symbiotic (mycorrhizal) fungus. This study exemplifies the possibilities of diving deeper into the genomic features involved in population divergence and speciation, also for nonmodel organisms, and how molecular and analytical tools will improve our understanding of the patterns and mechanisms that underlie adaptation to habitats, population divergence and dispersal limitation of fungi.

Genetic and pathological characteristics of Cryptococcus gattii and Cryptococcus neoformans var. neoformans from meningoencephalitis in autochthonous goats and mouflons, Sardinia, Italy

In this study, we examined in Sardinia the brain of 555 autochthonous sheep, 50 goats, and 4 mouflons which were found affected by neurological signs. We found 6 goats and one mouflon with meningoencephalitis caused by Cryptococcus sp. There was no evidence of cryptococcal infections in any of the examined sheep. MLST genotyping on Cryptococcus sp. isolates identified Cryptococcus gatti genotype AFLP4/VGI and Cryptococcus neoformans var. neoformans genotype AFLP2/VNIV. Phylogenetically, all Cryptococcus gattii isolates fell within the autochthonous animal, human and environmental Mediterranean isolate cluster, forming a distinct branch along with environmental strains from Alicante, in the southern Mediterranean coast of Spain.

Eugenia calycina Cambess extracts and their fractions: Their antimicrobial activity and the identification of major polar compounds using electrospray ionization FT-ICR mass spectrometry

Eugenia calycina, which is described as “red pitanga or pitanga cherry of cerrado,” is widely distributed in the Cerrado area of Brazil. Its leaf and bark extracts are used in folk medicine for many applications. In this study, the compositions of the major polar compounds of the bark and leaf extracts and their fractions were obtained from a liquid–liquid extraction using hexane, dichloromethane, ethyl acetate, and water. They were then evaluated using electrospray ionization negative FT-ICR mass spectrometry (ESI(−) FT-ICR MS), which revealed a large number of oxygen-containing compounds, such as flavonoids, terpenes, tanins, steroids, and fat acids. The biological activity of these extracts towards several bacterial and fungal strains was then evaluated. The highest activity was found using aqueous fractions, in which the ESI(−) FT-ICR MS analysis revealed compounds with a high content of oxygen (e.g., glycosed flavonoids, tannins, and polyphenolic compounds) against Cryptococcus sp. D (minimum inhibitory concentration [MIC]=15.62μg/mL). Strong activity was also found using the hexanic fractions—in which the ESI(−) FT-ICR MS analysis revealed that the compounds contained a decreased amount of oxygen (e.g., fat acids and steroids)—towards Cryptococcus gatti L48, Cryptococcus neoformans L3 (MIC=31.2μg/mL), and Cryptococcus sp. D (MIC=62.5μg/mL). Therefore, antimicrobial assays using the bark/leaf extracts of E. calycina present prospects for the research of active substances that may be used for the treatment of cryptococcosis, a disease that is common in immunosuppressed patients.

Cryptococcus gatti serotype B isolated in Sikkim (North-East India)—A new geographical niche

Cryptococcus neoformans and Cryptococcus gatti both cause infection in immunocompromised patients. We report a case of meningitis with C. gatti in an AIDS patient. This case to our knowledge is the first case of C. gatti being reported from Sikkim (North East India).