Disseminated cerebral cryptococcoma mimicking glioblastoma - A case report."

We discuss a rare instance of cryptococcoma caused by Cryptococcus gattii in a 55-year-old woman initially treated for suspected COVID bronchopneumonia. The diagnosis posed a challenge due to vague symptoms and unclear imaging findings suggesting malignancy. Postoperative samples confirmed the presence of Cryptococcus gattii through culture of brain tissue and blood. Appropriate therapy was initiated, but despite treatment, it led to a fatal outcome. The case emphasizes the crucial role of microbiologist in early diagnosis of fungal infections of Central Nervous System. Additionally, the delayed diagnosis in immunocompetent individuals highlights the critical need for early recognition and intervention to mitigate potentially fatal outcomes.

Anti-GM-CSF autoantibodies predict outcome of cryptococcal meningitis in patients not infected with HIV: A cohort study.

OBJECTIVES: To explore the seroprevalence of anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies in non-HIV cryptococcal meningitis (CM) and assess its predictive value for survival. METHODS: This is a retrospective study of 12 years of non-HIV CM. We detected serum anti-GM-CSF autoantibodies, and evaluated the clinical features and outcomes, together with the exploration of prognostic factors for 2-week and 1-year survival. RESULTS: A total of 584 non-HIV CM cases were included. 301 of 584 patients (51.5%) were phenotypically healthy. 264 Cryptococcus isolates were obtained from cerebrospinal fluid (CSF) culture, of which 251 were identified as C. neoformans species complex and 13 as C. gattii species complex. Thirty-seven of 455 patients (8.1%) tested positive for serum anti-GM-CSF autoantibodies. Patients with anti-GM-CSF autoantibodies were more susceptible to C. gattii species complex infection (66.7% vs. 6.3%; p < 0.001) and more likely to develop pulmonary mass lesions with a diameter >3 centimetres (42.9% vs. 6.5%; p 0.001). Of 584 patients 16 (2.7%) died within 2 weeks, 77 of 563 patients (13.7%) died at 1 year, and 93 of 486 patients (19.1%) lived with disabilities at 1 year. Univariant Cox regression analysis found that anti-GM-CSF autoantibodies were associated with lower 1-year survival (HR, 2.66; 95% CI, 1.34-5.27; p 0.005). Multivariable Cox proportional hazards modelling revealed that CSF cryptococcal antigen titres ≥1:1280 were associated with both, reduced 2-week and 1-year survival rates (HR, 5.44; 95% CI, 1.23-24.10; p 0.026 and HR, 5.09; 95% CI, 1.95-13.26; p 0.001). DISCUSSION: Presence of serum anti-GM-CSF autoantibodies is predictive of poor outcomes, regardless of host immune status and the causative Cryptococcus species complex.

Cryptococcus gattii strains with a high phagocytosis phenotype by macrophages display high pathogenicity at the early stage of infection in vivo.

Cryptococcus gattii (Cg) is a facultative intracellular pathogen that can replicate and disseminate in mammalian macrophages, causing life-threatening cryptococcosis in both immunocompetent and immunocompromised individuals. Cryptococcus-macrophage interactions are crucial for cryptococcosis prognosis. However, the relationship between Cg pathogenicity and phagocytosis by macrophages has not yet been investigated in depth. In this study, a series of in vitro and in vivo experiments were conducted to investigate the interaction between macrophages and Cg. Flow cytometry was used to detect the phagocytic phenotypes of the Cg strains within macrophages. Scanning electron microscopy, transmission electron microscopy, and immunofluorescence were used to observe phagocytosis and proliferation, respectively. Survival and lung fungal burden tests were also performed. Our results show that Cg cells display different phagocytosis phenotypes, which are independent of the molecular type. Within macrophages, the high phagocytosis phenotype (HP) strains obtain higher intracellular proliferation than the low phagocytosis phenotype (LP) strains. At the early stage of infection in vivo, HP-inducing permissive granulomas within the lungs seldom limit the dissemination of cryptococci. In addition, HP strains could inhibit the formation of M1-type macrophages, proliferate intracellularly and disseminate extracellularly, and cause hypoxia induced by mucus and acidic polysaccharide accumulation in pulmonary alveoli much earlier than LP strains in vivo. Our work reveals that Cg displays diverse interactions with macrophages, which may enhance our understanding of the pathogenicity of this life-threatening pathogen.

Post-infectious inflammatory response syndrome in an HIV-negative patient after Cryptococcus gattii meningoencephalitis: a case report and review of the literature.

BACKGROUND: Cryptococcal meningitis (CM) is an inflammatory mycosis of the central nervous system caused by meninge infection or brain parenchyma with Cryptococcus species. It is associated with high morbidity and mortality, and patients with acquired immune deficiency syndrome are particularly susceptible. There have been increasing reports of CM in HIV-negative patients in China over the last few years. CASE PRESENTATION: A 31-year-old healthy Chinese male presented with fever and gradually developed headache, projectile vomiting, and other manifestations that were later confirmed as Cryptococcus gattii meningoencephalitis. However, multiple disease changes occurred during the course of treatment, and the regimen was accordingly modified after the diagnosis of post-infectious inflammatory response syndrome (PIIRS). The patient eventually recovered. CONCLUSION: There has been a growing trend in the incidence of C. gattii meningoencephalitis in HIV-negative patients. It shows rapid onset and severe prognosis. This case report can provide a reference to treat PIIRS following CM in HIV-negative patients.

Current Epidemiology and Clinical Features of Cryptococcus Infection in Patients Without Human Immunodeficiency Virus: A Multicenter Study in 46 Hospitals in Australia and New Zealand.

BACKGROUND: Patients without human immunodeficiency virus (HIV) are increasingly recognized as being at risk for cryptococcosis. Knowledge of characteristics of cryptococcosis in these patients remains incomplete. METHODS: We conducted a retrospective study of cryptococcosis in 46 Australian and New Zealand hospitals to compare its frequency in patients with and without HIV and describe its characteristics in patients without HIV. Patients with cryptococcosis between January 2015 and December 2019 were included. RESULTS: Of 475 patients with cryptococcosis, 90% were without HIV (426 of 475) with marked predominance in both Cryptococcus neoformans (88.7%) and Cryptococcus gattii cases (94.3%). Most patients without HIV (60.8%) had a known immunocompromising condition: cancer (n = 91), organ transplantation (n = 81), or other immunocompromising condition (n = 97). Cryptococcosis presented as incidental imaging findings in 16.4% of patients (70 of 426). The serum cryptococcal antigen test was positive in 85.1% of tested patients (319 of 375); high titers independently predicted risk of central nervous system involvement. Lumbar puncture was performed in 167 patients to screen for asymptomatic meningitis, with a positivity rate of 13.2% where meningitis could have been predicted by a high serum cryptococcal antigen titer and/or fungemia in 95% of evaluable cases. One-year all-cause mortality was 20.9% in patients without HIV and 21.7% in patients with HIV (P = .89). CONCLUSIONS: Ninety percent of cryptococcosis cases occurred in patients without HIV (89% and 94% for C. neoformans and C. gattii, respectively). Emerging patient risk groups were evident. A high level of awareness is warranted to diagnose cryptococcosis in patients without HIV.

Epidemiology, management and outcomes of Cryptococcus gattii infections: A 22-year cohort.

BACKGROUND: Cryptococcus gattii is a globally endemic pathogen causing disease in apparently immune-competent hosts. We describe a 22-year cohort study from Australia's Northern Territory to evaluate trends in epidemiology and management, and outcome predictors. METHODS: A retrospective cohort study of all C. gattii infections at the northern Australian referral hospital 1996-2018 was conducted. Cases were defined as confirmed (culture-positive) or probable. Demographic, clinical and outcome data were extracted from medical records. RESULTS: 45 individuals with C. gattii infection were included: 44 Aboriginal Australians; 35 with confirmed infection; none HIV positive out of 38 tested. Multifocal disease (pulmonary and central nervous system) occurred in 20/45 (44%). Nine people (20%) died within 12 months of diagnosis, five attributed directly to C. gattii. Significant residual disability was evident in 4/36 (11%) survivors. Predictors of mortality included: treatment before the year 2002 (4/11 versus 1/34); interruption to induction therapy (2/8 versus 3/37) and end-stage kidney disease (2/5 versus 3/40). Prolonged antifungal therapy was the standard approach in this cohort, with median treatment duration being 425 days (IQR 166-715). Ten individuals had adjunctive lung resection surgery for large pulmonary cryptococcomas (median diameter 6cm [range 2.2-10cm], versus 2.8cm [1.2-9cm] in those managed non-operatively). One died post-operatively, and 7 had thoracic surgical complications, but ultimately 9/10 (90%) treated surgically were cured compared with 10/15 (67%) who did not have lung surgery. Four patients were diagnosed with immune reconstitution inflammatory syndrome which was associated with age <40 years, brain cryptococcomas, high cerebrospinal fluid pressure, and serum cryptococcal antigen titre >1:512. CONCLUSION: C. gattii infection remains a challenging condition but treatment outcomes have significantly improved over 2 decades, with eradication of infection the norm. Adjunctive surgery for the management of bulky pulmonary C. gattii infection appears to increase the likelihood of durable cure and likely reduces the required duration of antifungal therapy.

[A case of Cryptococcus gattii pneumonia].

Cryptococcus gattii often causes meningitis, but rarely causes pulmonary infections. Here, we reported a patient with asymptomatic pulmonary cryptococcosis caused by Cryptococcus gattii. The patient presented to the thoracic surgery department with an isolated pulmonary nodule that had been present for three years and underwent a thoracoscopic pulmonary wedge resection. Postoperative pathology was consistent with Cryptococcus gattii infection. Although the incidence of Cryptococcus gattii infection is lower than that of Cryptococcus neoformans, the neurological involvement is common and has severe complications. In this report, the risk factors, symptoms, diagnosis, treatment, and prognosis of Cryptococcus gattii pneumonia were discussed to improve clinical awareness of this disease.

Adjuvant Pam3CSk4 does not improve the immunization against Cryptococcus gattii infection in C57BL/6 mice.

Background: Cryptococcosis is a relevant invasive fungal infection that affects immunocompromised and immunocompetent individuals when caused by Cryptococcus gattii. Host innate and adaptive immune responses can be subverted by C. gattii, that blocks the differentiation of T helper (Th) 1 and Th17 cells, which are involved in the protection against cryptococcosis. Moreover, the macrophage polarization is modulated by C. gattii infection that requires a balance in the macrophage subsets to control the C. gattii infection. Toll-like receptor (TLR) 2 agonists are important immunomodulators favoring a pro-inflammatory response with potential fungicidal activity, and TLR2 agonists have been used as adjuvants in vaccines against infections caused by bacteria or viruses. Therefore, this work aimed to evaluate the immunomodulatory effect of the tripalmitoyl lipopeptide S-glycerol cysteine (Pam3CSK4 or P3C4), a TLR2 agonist, as an adjuvant in the vaccination against C. gattii infection. Methods and Results: C57BL/6 mice were immunized with 2 × 107 inactivated yeasts of C. gattii via intranasal route on day 1, 14 and 28 (Immunized group). Immunization was associated with 1µg or 10µg of adjuvant P3C4 (Immunized+P3C4-1µg or Immunized+P3C4-10 µg), followed by C. gattii infection on day 42 after the immunization protocol. Immunized+P3C4-1 µg group had reduced levels of IgG1, IgG2a and IgA and no significant difference in the IgG and IgM anti-GXM antibody titer was detected, compared to the Immunized group. High levels of IL-17 and IL-1ß in lung tissue of mice from the Immunized+P3C4-1µg group did not promote a predominance of Th17 cells, in contrast, the frequency of TLR2+ cells was increased in immunized mice that received 1 µg of P3C4. The reduction in the relative expression of T-bet and high levels of Foxp3 detected in the lungs of the Immunized+P3C4-1µg group suggest a prevalence of regulatory T cells in the tissue, which did not contribute to the control of C. gattii infection. The immunization protocol associated with 10 µg of adjuvant P3C4 induced high levels of IL-17 in the lung tissue, whereas the levels of pro-inflammatory cytokines were downregulated. To evaluate the effect of adjuvant P3C4 in the control of C. gattii infection, quantification of the fungal burden in the lungs was performed by the CFU assay, and the groups with adjuvant P3C4 showed a pulmonary C. gattii burden that was not significantly altered when compared with the immunized group. The mice that received 1 µg of adjuvant P3C4 had a lower percentage of inflammatory infiltrate in the lungs. Conclusion: The immunomodulatory effect of P3C4, associated with the immunization protocol, plays an imbalance between pro- and anti-inflammatory response in the lungs that did not favor a protection against C. gattii infection, which is related to the immune response characterized by a suppressive/regulatory profile in the pulmonary microenvironment after C. gattii infection.

Cryptococcal Meningitis in a Mexican Neurological Center.

BACKGROUND: Cryptococcal meningitis, one of the most severe infections affecting the central nervous system, often involves severe neurological sequels and high mortality. METHODS: A retrospective review was performed, including 76 cases admitted in a 10-year period at a neurological referral center in Mexico City. From 68 isolates, 52 fungal specimens were identified as part of the Cryptococcus neoformans var. neoformans complex, 15 as C. neoformans var gattii complex, and one as Cryptococcus non- neoformans/gattii . RESULTS: Higher cryptococcal meningitis incidence and severity were found in HIV-infected men; other risk factors frequently observed were diabetes mellitus and labor exposure to poultry. The main clinical manifestations were subacute headache, cognitive alterations, and photophobia (exclusively in HIV patients). MRI was highly sensitive for pathologic findings such as meningeal enhancements and cryptococcomas, most of them associated to C. neoformans complex. Eleven patients developed severe brain vasculitis, as observed by transcranial Doppler. Hydrocephalus with intracranial hypertension was the most frequent complication. CONCLUSIONS: One-half of the population died, and the rest had neurological sequels, mainly neuropsychiatric manifestations and secondary headaches. These patients developed severe functional limitations in performing daily activities in an independent manner.

Reversible deafness and blindness in Cryptococcus gattii meningitis with a ventriculoperitoneal shunt: A case report and literature review.

Cryptococcus gattii (C. gattii) has been considered a leading cause of meningitis in immunocompetent hosts in tropical and subtropical regions. Visual loss is common but hearing impairment is relatively infrequent in C. gattii meningitis. Notably, there have been limited studies on the etiology, and especially therapy of auditory and ocular complications associated with C. gattii meningitis. Here we report a case of reversible deafness and blindness treated with a ventriculoperitoneal shunt (VPS) surgery in C. gattii meningitis. This case indicated that elevated intracranial pressure (ICP) may play a role in the concurrent hearing and vision impairments associated with C. gattii meningitis and the early VPS surgery after the initiation of the antifungal therapy may effectively improve both hearing and vision in this condition.

Effects of combination of Cryptococcus gattii and IFN-γ, IL-4 or IL-27 on human bronchial epithelial cells.

BACKGROUND: Airway epithelial cells are crucial for the establishment of cryptococcosis. In experimental cryptococcosis, the Th2 immune response is associated with host susceptibility, while Th1 cells are associated with protection. The absence of IL-27 receptor alpha in mice favor the increase Cryptococcus neoformans burden in the lung. Here, we evaluated the effects of the combination of IL-4, IFN-γ or IL-27 with C. gattii on human bronchial epithelial cells (BEAS-2B). METHODS: BEAS-2B were stimulated with IL-4, IFN-γ or IL-27 (100 ng/mL) and/or live yeast forms of C. gattii (multiplicities of infection (MOI) of 1-100) and vice-versa, as well as with heat-killed cells of C. gattii for 24 h. RESULTS: None of the C. gattii MOIs had cytotoxic effects on BEAS-2B when compared to control. The cells stimulated by cytokines (IL-4, IFN-γ or IL-27) followed by live yeast forms of C. gattii (MOI of 100) infection and vice-versa demonstrated a reduction in IL-6, IL-8 and/or CCL2 production and activation of STAT6 (induced by IL-4) and STAT1 (induced by IL-27 or IFN-γ) when compared to cells stimulated with C. gattii, IL-4, IFN-γ or IL-27. In the combination of cytokines and heat-killed cells of C. gattii, no inhibition of these inflammatory parameters was observed. The growth of C. gattii was increased while the phagocytosis of live yeast forms of C. gattii in the BEAS-2B were reduced in the presence of IL-4, IFN-γ or IL-27. Conclusion The association of live yeast forms, but not heat-killed yeast forms, of C. gattii with IL-4, IFN-γ or IL-27 induced an anti-inflammatory effect.

MDA5 signaling induces type 1 IFN- and IL-1-dependent lung vascular permeability which protects mice from opportunistic fungal infection.

Lungs balance threat from primary viral infection, secondary infection, and inflammatory damage. Severe pulmonary inflammation induces vascular permeability, edema, and organ dysfunction. We previously demonstrated that poly(I:C) (pICLC) induced type 1 interferon (t1IFN) protected mice from Cryptococcus gattii (Cg) via local iron restriction. Here we show pICLC increased serum protein and intravenously injected FITC-dextran in the lung airspace suggesting pICLC induces vascular permeability. Interestingly, pICLC induced a pro-inflammatory signature with significant expression of IL-1 and IL-6 which depended on MDA5 and t1IFN. Vascular permeability depended on MDA5, t1IFN, IL-1, and IL-6. T1IFN also induced MDA5 and other MDA5 signaling components suggesting that positive feedback contributes to t1IFN dependent expression of the pro-inflammatory signature. Vascular permeability, induced by pICLC or another compound, inhibited Cg by limiting iron. These data suggest that pICLC induces t1IFN which potentiates pICLC-MDA5 signaling increasing IL-1 and IL-6 resulting in leakage of antimicrobial serum factors into lung airspace. Thus, induced vascular permeability may act as an innate defense mechanism against opportunistic fungal infection, such as cryptococcosis, and may be exploited as a host-directed therapeutic target.

Comparison of features and outcomes between HIV-negative patients with Cryptococcus gattii meningitis and Cryptococcus neoformans meningitis in South China.

OBJECTIVES: The objective of this study is to compare the epidemiologic, clinical, laboratory, and imaging features, and outcomes in patients with Cryptococcus gattii meningitis (CGM) and Cryptococcus neoformans meningitis (CNM). METHODS: We performed a retrospective study of HIV-negative patients with CGM and CNM (2015-2021) distinguished by metagenomic next-generation sequencing in cerebrospinal fluid in South China. RESULTS: A total of 81 patients (17 CGM, 64 CNM) were enrolled (72.8% male, median age 49 years, range 21-77 years), and CGM patients were younger (median, 43 vs 53 years, p = .005). Of 17 CGM, VGI and VGII accounted for 70.6% and 29.4%, respectively. CGM patients had less underlying diseases (7/17 [41.2%] vs 48/64 [75%], p = .018) and focal neurologic deficit (3/17 [17.6%] vs 35/64 [54.7%], p = .022), had higher intracranial pressure (15/17 [88.2%] vs 25/64 [39.1%], p = .002), more meningeal enhancement (14/17 [82.4%] vs 32/64 [50%], p = .034), less parenchymal involvement (median, 1 vs 3, p = .018), more lung cryptococcomas (6/12 [50%] vs 6/47 [12.8%], p = .014), faster CSF fungal clearance (p = .004), less complications (median, 1 vs 3, p < .001), and more favourable outcomes (16/17 [94.1%] vs 41/64 [64.1%], p = .035). CONCLUSIONS: This study demonstrated that species identification helps to guide therapy and predict outcomes.

Prevalence of Cryptococcus gattii in Ugandan HIV-infected patients presenting with cryptococcal meningitis.

INTRODUCTION: Cryptococcal meningitis (CM) is a life threatening disease and leading cause of opportunistic fungal-related mortality in HIV/AIDS. Most CM infections are caused by C. neoformans species complexes but the prevalence of Cryptococcus gattii species complexes in Uganda is unknown however, it is known in a few other parts of Africa. We estimated the prevalence of C. gattii in patients living with HIV and a diagnosis of cryptococcal meningitis in Uganda. METHODS: Cryptococcus isolates (n = 200) obtained from cerebrospinal fluid of patients with CM recruited at the Infectious Diseases Institute, Kampala, Uganda, were tested by phenotypic methods. The Cryptococcus isolates were sub-cultured on Sabouraud Dextrose Agar plates for 48 hours. The yeast colonies were examined by India ink stain, urea hydrolysis, and C. gattii was identified by blue pigmentation on CGB agar. The results were analyzed for frequency of C. gattii. Patient demographic characteristics were collected from the case record forms. RESULTS: From the 200 patients' case record forms, 87 (43.5%) were female and 113 (56.5%) were male. The median age was 35 (19-64) years. Most patients, 93% (187/200) were from Central Uganda in the districts of Kampala and Wakiso. 97.51% (157/161) of the patients had absolute CD4 lymphocyte counts of less than 200 cells per cubic millimeter; 1.86% (3/161) 200-350 cells per cubic millimeter and 0.62% (1/161) above 500 cells per cubic millimeter. 45.4% (74/163) were not yet on HAART and 54.6% (89/163) were on HAART. 66.7% (58/87) had poor adherence to HAART treatment and 33.3% (29/87) had reported good adherence to HAART treatment. A total of 200 clinical isolates of Cryptococcus isolates were tested. No (0% (0/200) C. gattii was identified among the Cryptococcus isolates. CONCLUSION: In this study among patients living with HIV and a diagnosis of cryptococcal meningitis in Uganda, we found no C. gattii infections.

Performance of Metagenomic Next-Generation Sequencing for the Diagnosis of Cryptococcal Meningitis in HIV-Negative Patients.

Objectives: Metagenomic next-generation sequencing (mNGS) has been applied more and more widely for the diagnosis of infectious diseases, but its performance in the diagnosis of cryptococcal meningitis (CM) remains unclear. Methods: Cerebrospinal fluid (CSF) samples from 197 HIV-negative patients with suspected central nervous system infections were tested simultaneously by mNGS and routine methods [India ink staining, fungal culture, or cryptococcal antigen (CrAg) tests]. The performance of mNGS was evaluated. Results: Of the 197 enrolled cases, 46 (23.4%) cases were finally diagnosed with CM, including 43 (93.5%) Cryptococcus neoformans infections and 3 (6.5%) Cryptococcus gattii infections. The sensitivity, specificity, positive predictive value, negative predictive value, and concordance rate of mNGS were 93.5% [95% confidence interval (CI) at 86.4%~100.0%], 96.0% (95% CI at 92.9%~99.1%), 87.8%, 98.0%, and 95.4%, respectively. Comparing to the conventional diagnostic methods, the sensitivity and concordance rate of mNGS were slightly lower than those of CrAg tests (97.4%) but higher than those of India ink (63.0%) and culture (76.7%). Besides, mNGS had a sensitivity of 100.0% against culture. It should be noted that mNGS could identify Cryptococcus at species level; C. gattii of the 3 cases was only distinguished by mNGS. Conclusions: CSF mNGS can be considered as a supplementary test to diagnose CM and directly distinguish C. gattii from C. neoformans in clinical specimens.

Screening of the Pandemic Response Box Reveals an Association between Antifungal Effects of MMV1593537 and the Cell Wall of Cryptococcus neoformans, Cryptococcus deuterogattii, and Candida auris.

There is an urgent unmet need for novel antifungals. In this study, we searched for novel antifungal activities in the Pandemic Response Box, a collection of 400 structurally diverse compounds in various phases of drug discovery. We identified five molecules which could control the growth of Cryptococcus neoformans, Cryptococcus deuterogattii, and the emerging global threat Candida auris. After eliminating compounds which demonstrated paradoxical antifungal effects or toxicity to mammalian macrophages, we selected compound MMV1593537 as a nontoxic, fungicidal molecule for further characterization of antifungal activity. Scanning electron microscopy revealed that MMV1593537 affected cellular division in all three pathogens. In Cryptococcus, MMV1593537 caused a reduction in capsular dimensions. Treatment with MMV1593537 resulted in increased detection of cell wall chitooligomers in these three species. Since chitooligomers are products of the enzymatic hydrolysis of chitin, we investigated whether surface chitinase activity was altered in response to MMV1593537 exposure. We observed peaks of enzyme activity in C. neoformans and C. deuterogattii in response to MMV1593537. We did not detect any surface chitinase activity in C. auris. Our results suggest that MMV1593537 is a promising, nontoxic fungicide whose mechanism of action, at least in Cryptococcus spp, requires chitinase-mediated hydrolysis of chitin. IMPORTANCE The development of novel antifungals is a matter of urgency. In this study, we evaluated antifungal activities in a collection of 400 molecules, using highly lethal fungal pathogens as targets. One of these molecules, namely, MMV1593537, was not toxic to host cells and controlled the growth of isolates of Cryptococcus neoformans, C. deuterogattii, C. gattii, Candida auris, C. albicans, C. parapsilosis, and C. krusei. We tested the mechanisms of antifungal action of MMV1593537 in the Cryptococcus and C. auris models and concluded that the compound affects the cell wall, a structure which is essential for fungal life. At least in Cryptococcus, this effect involved chitinase, an enzyme which is required for remodeling the cell wall. Our results suggest that MMV1593537 is a candidate for future antifungal development.

Cryptococcal meningitis due to Cryptococcus gattii in an immunocompetent patient: uncommon presentation of a thunderclap headache.

Thunderclap headache is a medical emergency presented as the worst headache ever, is characterised by an abrupt onset and maximal intensity within seconds to minutes. However, cerebrovascular causes are among the most common causes of thunderclap headache, and other non-vascular life-threatening aetiologies should be considered in evaluating a patient. We describe a 23-year-old previously healthy Latino woman who presented to our hospital after a month of repetitive severe, abrupt-onset headaches. Her prior medical history was unremarkable. After a normal brain MRI with angio-MRI, a lumbar puncture was performed with normal opening pressure, hypoglycorrhachia, increased proteins and a leucocyte; India ink staining was positive for encapsulated yeast, cultures were positive for Cryptococcus gattii The patient received appropriate antifungal treatment with a good response. This case highlights the particular presentation of cryptococcal meningitis due to C. gattii among immunocompetent patients.

Nicotiana benthamiana as a model for studying Cryptococcus-plant interaction.

Cryptococcus gattii, an environmental yeast isolated from plants, is one of the agents of cryptococcosis. Here, we aimed to develop a plant model to study C. gattii-plant interaction, since it is unclear how it affects the plant and the yeast. We tested three inoculation methods (scarification, infiltration, and abrasion) in three plant species: Arabidopsis thaliana, Nicotiana tabacum, and N. benthamiana. Cryptococcus gattii was able to grow in all three models, with a peak of yeast cell burden after 7 days, without any pathological effects. Furthermore, the fungal burden was reduced later, confirming that C. gattii is not a phytopathogen. Cryptococcus gattii proliferation was higher in N. benthamiana, which presented an increase in the hydrogen peroxide content, antioxidant system activity, and indoleacetic acid (IAA) production. Cryptococcus gattii colonies recovered from N. benthamiana presented lower ergosterol content, reduced capsule, and increased growth rate in vitro and inside macrophages. In vitro, IAA altered C. gattii morphology and susceptibility to antifungal drugs. We hypothesize that C. gattii can temporarily colonize plant living tissues, which can be a potential reservoir of yeast virulence, with further dissemination to the environment, birds, and mammals. In conclusion, N. benthamiana is suitable for studying C. gattii-plant interaction.

Consensus guidelines for the diagnosis and management of cryptococcosis and rare yeast infections in the haematology/oncology setting, 2021.

Cryptococcosis caused by the Cryptococcus neoformans-Cryptococcus gattii complex is an important opportunistic infection in people with immunodeficiency, including in the haematology/oncology setting. This may manifest clinically as cryptococcal meningitis or pulmonary cryptococcosis, or be detected incidentally by cryptococcal antigenemia, a positive sputum culture or radiological imaging. Non-Candida, non-Cryptococcus spp. rare yeast fungaemia are increasingly common in this population. These consensus guidelines aim to provide clinicians working in the Australian and New Zealand haematology/oncology setting with clear guiding principles and practical recommendations for the management of cryptococcosis, while also highlighting important and emerging rare yeast infections and their recommended management.

Comparison of clinical and biological characteristics of HIV-infected patients presenting Cryptococcus neoformans versus C. curvatus/C. laurentii meningitis.

BACKGROUND: Cryptococcal meningitis is mainly caused by Cryptococcus neoformans/C. gattii complex. We compared the clinical, biological, and antifungal susceptibility profiles of isolates from HIV-Infected Patients (HIVIP) with C. neoformans (Cn) versus C. curvatus/C. laurentii (Cc/Cl) meningitis. METHODS: Comparative analytical study were conducted. Apart from patients' clinical data, the following analysis were performed and the results were compared in both groups: biochemical examination, cryptococcal antigen test, India ink staining, and culture on Cerebral Spinal Fluid (CSF), strains identification by mass spectrometry, ITS sequencing, PCR serotyping and antifungal susceptibility. The main outcome variable was the "species of Cryptococcus identified", which was compared to other variables of the same type using the Pearson Chi-square test or the Fisher exact test. RESULTS: A total of 23 (79.3%) Cn meningitis cases versus 6 (20.7%) Cc/Cl meningitis were retained. Cn meningitis was more frequently associated with headache (100% vs 50%, p = 0.005) than Cc/Cl meningitis and meningeal signs were more frequent in Cn infected patients. Biologically, hypoglycorrhachia and low CD4 count were more observed in Cn group (90% vs 20% of patients, p = 0.01; 45.6 vs 129.8 cells/µL, p = 0.02, respectively). A higher proportion of Cn strains (91.3%) showed a low Minimum Inhibitory Concentration (MIC) (< 8 mg/L) for fluconazole compared to Cc/Cl strains (66.7%). Also, Cc/Cl strains resistant to 5-flucytosine and amphotericin B were found in 16.7% of cases for each of the two antifungal agents. Cryptococcus detection by routine analysis (India ink, culture, and antigens) was better for Cn samples than Cc/Cl. Except ITS sequencing, which identified all strains of both groups, mass spectrometry and serotyping PCR identified Cn strains better than Cc/Cl (100% vs 80%, p = 0.1; 100% vs 0%, p < 0.0001, respectively). After treatment with amphotericin B, 5-flucytosine, and fluconazole in both groups, the outcome was similar. CONCLUSIONS: Clinical presentation of Cn meningitis is certainly more severe than that of Cc/Cl meningitis, but Cc/Cl infection should be considered in the management of HIVIP with meningeal syndrome because of the diagnostic difficulty and the high MICs of antifungal agents required for the treatment of meningitis due to these cryptococcal species.