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"Cryptococcus - isolation "
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Efficacy of adjunctive sertraline for the treatment of HIV-associated cryptococcal meningitis: an open-label dose-ranging study
by
Musubire, Abdu
,
Bahr, Nathan C
,
Velamakanni, Sruti S
in
Adult
,
AIDS-Related Opportunistic Infections - drug therapy
,
Antidepressive Agents - administration & dosage
2016
Cryptococcus is the most common cause of adult meningitis in Africa. We assessed the safety and microbiological efficacy of adjunctive sertraline, previously shown to have in-vitro and in-vivo activity against cryptococcus.
In this open-label dose-finding study, we recruited HIV-infected individuals with cryptococcal meningitis who presented to Mulago Hospital in Kampala, Uganda between Aug 14, 2013, and Aug 30, 2014. To assess safety and tolerability, the first 60 participants were given sertraline at escalating doses of 100 mg/day, 200 mg/day, 300 mg/day, or 400 mg/day as induction therapy for 2 weeks, followed by consolidation therapy with 200 mg/day for an additional 8 weeks. From Nov 29, 2013, participants were randomly assigned (1:1) to receive open-label sertraline at predetermined doses of 200 mg/day, 300 mg/day, or 400 mg/day as induction therapy for 2 weeks, followed by consolidation therapy with 200 mg/day for 8 weeks. Dose assignment was made via computer-generated, permuted block randomisation stratified by antiretroviral therapy (ART) status for people with a first episode of meningitis. The primary outcome was 2-week cerebrospinal fluid (CSF) clearance rate of cryptococcus, termed early fungicidal activity, measured in patients with a first episode of culture-positive meningitis and two or more CSF cultures. This study is registered with ClinicalTrials.gov, number NCT01802385.
Of the 330 individuals assessed, 172 HIV-infected adults with cryptococcal meningitis were enrolled. We gave 100 mg/day sertraline to 17 patients, 200 mg/day to 12 patients, 300 mg/day to 14 patients, and 400 mg/day to 17 patients. 112 participants were randomly assigned to receive sertraline at 200 mg (n=48), 300 mg (n=36), or 400 mg (n=28) daily for the first 2 weeks, and 200 mg/day thereafter. The final population consisted of 17 participants in the 100 mg group, 60 in the 200 mg group, 50 in the 300 mg group, and 45 in the 400 mg in group. Participants receiving any sertraline dose averaged a CSF clearance rate of −0·37 colony forming units per mL per day (95% CI −0·41 to −0·33). Incidence of paradoxical immune reconstitution inflammatory syndrome was 5% (two of 43 newly starting ART) and no cases of relapse occurred over the 12-week study period. 38 (22%) of 172 participants had died at 2 weeks, and 69 (40%) had died at 12 weeks. Six grade 4 adverse events occurred in 17 participants receiving 100 mg, 14 events in 60 participants receiving 200 mg, 19 events in 50 participants receiving 300 mg, and eight events in 45 participants receiving 400 mg. Grade 4 or 5 adverse event risk did not differ between current US Food and Drug Administration-approved dosing of 100–200 mg/day and higher doses of 300–400 mg/day (hazard ratio 1·27, 95% CI 0·69–2·32; p=0·45).
Participants receiving sertraline had faster cryptococcal CSF clearance and a lower incidence of immune reconstitution inflammatory syndrome and relapse than that reported in the past. This inexpensive and off-patent oral medication is a promising adjunctive antifungal therapy.
National Institutes of Health, Grand Challenges Canada.
Journal Article
Point-of-Care Diagnosis and Prognostication of Cryptococcal Meningitis With the Cryptococcal Antigen Lateral Flow Assay on Cerebrospinal Fluid
by
Kabanda, Taseera
,
Boulware, David R.
,
Klausner, Jeffrey D.
in
AIDS
,
Antigens
,
Biological and medical sciences
2014
The cryptococcal antigen (CRAG) lateral flow assay (LFA) had 100% sensitivity and specificity on cerebrospinal fluid samples. Pretreatment LFA titers correlated with quantitative cultures (R 2 = 0.7) and predicted 2- and 10-week mortality. The CRAG LFA is an accurate diagnostic assay for CSF and should be considered for point-of-care diagnosis of cryptococcal meningitis.
Journal Article
Comparison of the Early Fungicidal Activity of High-Dose Fluconazole, Voriconazole, and Flucytosine as Second-Line Drugs Given in Combination With Amphotericin B for the Treatment of HIV-Associated Cryptococcal Meningitis
by
Harrison, Thomas S
,
Bicanic, Tihana
,
Wilson, Douglas
in
Adult
,
AIDS
,
Antibiotics. Antiinfectious agents. Antiparasitic agents
2012
Background. HIV-associated cryptococcal meningitis is associated with an estimated 600 000 deaths worldwide per year. Current standard initial therapy consists of amphotericin B (AmB) plus flucytosine (5-FC), but 5-FC remains largely unavailable in Asia and Africa. Alternative, more widely available, and/or more effective antifungal combination treatment regimens are urgently needed. Methods. Eighty HIV-seropositive, antiretroviral naive patients presenting with cryptococcal meningitis were randomized to 4 treatment arms of 2 weeks duration: group 1, AmB (0.7-1 mg/kg) and 5-FC (25 mg/kg 4 times daily); group 2, AmB (0.7-1 mg/kg) and fluconazole (800 mg daily); group 3, AmB (0.7-1 mg/kg) and fluconazole (600 mg twice daily); and group 4, AmB (0.7-1 mg/kg) and voriconazole (300 mg twice daily). The primary end point was the rate of clearance of infection from the cerebrospinal fluid (CSF) or early fungicidal activity (EFA), as determined by results of serial, quantitative CSF cryptococcal cultures. Results. There were no statistically significant differences in the rate of clearance of cryptococcal colony-forming units (CFU) in CSF samples among the 4 treatment groups; the mean (± standard deviation) EFA for treatment groups 1, 2, 3, and 4 were -0.41 ± 0.22 log CFU/mL CSF/day, -0.38 ± 0.18 log CFU/mL CSF/day, -0.41 ± 0.35 log CFU/mL CSF/day, and -0.44 ± 0.20 log CFU/mL CSF/day, respectively. Overall mortality was 12% (9 of 78 patients died) at 2 weeks and 29% (22 of 75 patients died) at 10 weeks, with no statistically significant differences among groups. There were few laboratory abnormalities related to the second agents given; in particular, there were no statistically significant (≥grade 3) increases in alanine transaminase level or decreases in neutrophil count. Conclusions. There was no statistically significant difference in EFA between AmB in combination with fluconazole and AmB plus 5-FC for the treatment of HIV-associated cryptococcal meningitis. AmB plus fluconazole (800-1200 mg/day) represents an immediately implementable alternative to AmB plus 5-FC. AmB plus voriconazole is an effective alternative combination in patients not receiving interacting medications.
Journal Article
Combination Flucytosine and High-Dose Fluconazole Compared with Fluconazole Monotherapy for the Treatment of Cryptococcal Meningitis: A Randomized Trial in Malawi
2010
Background. Cryptococcal meningitis is a major cause of human immunodeficiency virus (HIV)–associated morbidity and mortality in Africa. Improved oral treatment regimens are needed because amphotericin B is neither available nor feasible in many centers. Fluconazole at a dosage of 1200 mg per day is more fungicidal than at a dosage of 800 mg per day, but mortality rates remain unacceptably high. Therefore, we examined the effect of adding oral flucytosine to fluconazole. Methods. From 13 February through 2 December 2008, HIV-seropositive, antiretroviral-naive patients experiencing their first episode of cryptococcal meningitis were randomized to receive (1) 14 days of fluconazole (1200 mg per day) alone or (2) in combination with flucytosine (100 mg/kg per day) followed by fluconazole (800 mg per day), with both groups undergoing 10 weeks of follow-up. The primary end point was early fungicidal activity, derived from quantitative cerebrospinal fluid cultures on days 1, 3, 7, and 14. Secondary end points were safety and 2- and 10-week mortality. Results. Forty-one patients were analyzed. Baseline mental status, cryptococcal burden, opening pressure, CD4+ cell count, and HIV load were similar between groups. Combination therapy was more fungicidal than fluconazole alone (mean early fungicidal activity ± standard deviation, −0.28±0.17 log colony-forming units [CFU]/mL per day vs −0.11±0.09 log CFU/mL per day; P<.001). The combination arm had fewer deaths by 2 weeks (10% vs 37%) and 10 weeks (43% vs 58%). More patients had grade III or IV neutropenia with combination therapy (5 vs 1, within the first 2 weeks; P=.20), but there was no increase in infection-related adverse events. Conclusions. The results suggest that optimal oral treatment for cryptococcal meningitis is high-dose fluconazole with flucytosine. Efforts are needed to increase availability of flucytosine in Africa. Clinical trials registration. isrctn.org Identifier: ISRCTN02725351.
Journal Article
Bronchoalveolar lavage fluid and lung biopsy tissue metagenomic next-generation sequencing in the diagnosis of pulmonary cryptococcosis
2024
To evaluate the diagnostic value of metagenomic next-generation sequencing (mNGS) in pulmonary cryptococcosis (PC) using bronchoalveolar lavage fluid (BALF) and lung biopsy tissue specimens.
In this retrospective study, 321 patients diagnosed with lower respiratory tract diseases who underwent mNGS using BALF and LBT samples, between January 2021 and December 2023 were included. Individuals were classified into PC and non-PC groups according to the diagnostic criteria for PC, and conventional fungal cultures were performed. A serum/BALF cryptococcal antigen (CrAg) test was performed in some patients with PC. The diagnostic efficiencies of three methods for PC (mNGS, conventional culture, and CrAg) were compared. Additionally, two mNGS methods were used in this study: original mNGS (OmNGS, testing time from January 2021 to December 2022) and modified mNGS (MmNGS, testing time from January to December 2023). The diagnostic efficiency of the two mNGS methods on PC was simultaneously compared.
Among the 321 patients, 23 (7.2%) had PC and 298 (92.8%) did not. Compared with the composite reference standard for PC diagnosis, the sensitivity, specificity, and accuracy of mNGS for PC were 78.3% (95% confidence interval [CI], 55.8%-91.7%), 98.7% (95% CI, 96.4%-99.6%), and 97.2% (95% CI, 94.7%-98.7%), respectively. The sensitivity of mNGS was similar to that of CrAg (80.0%, 12/15) (
> 0.05). The diagnostic sensitivity of both mNGS and CrAg was higher than that of conventional culture (35.0%, 7/20) (
= 0.006,
= 0.016), and the combined detection of mNGS and CrAg further improved the diagnostic sensitivity of PC (93.3%, 14/15). The area under the receiver operating characteristic curve of mNGS was superior to that of conventional culture (0.885 vs. 0.675). In addition, the diagnostic sensitivity of PC was higher than that of OmNGS (
= 0.046).
The sensitivity of mNGS is better than that of conventional culture. The combination of mNGS and CrAg improves the testing sensitivity of
. MmNGS could further improve the detection of
. Conventional PC detection methods are indispensable and mNGS can be used as a rapid and accurate auxiliary diagnostic method for PC.
Journal Article
Dynamic ploidy changes drive fluconazole resistance in human cryptococcal meningitis
by
Segal, Ella Shtifman
,
Rhodes, Johanna
,
Molloy, Síle F.
in
Antifungal agents
,
Clinical Medicine
,
Combination drug therapy
2019
Cryptococcal meningitis (CM) causes an estimated 180,000 deaths annually, predominantly in sub-Saharan Africa, where most patients receive fluconazole (FLC) monotherapy. While relapse after FLC monotherapy with resistant strains is frequently observed, the mechanisms and impact of emergence of FLC resistance in human CM are poorly understood. Heteroresistance (HetR) - a resistant subpopulation within a susceptible strain - is a recently described phenomenon in Cryptococcus neoformans (Cn) and Cryptococcus gattii (Cg), the significance of which has not previously been studied in humans.
A cohort of 20 patients with HIV-associated CM in Tanzania was prospectively observed during therapy with either FLC monotherapy or in combination with flucytosine (5FC). Total and resistant subpopulations of Cryptococcus spp. were quantified directly from patient cerebrospinal fluid (CSF). Stored isolates underwent whole genome sequencing and phenotypic characterization.
Heteroresistance was detectable in Cryptococcus spp. in the CSF of all patients at baseline (i.e., prior to initiation of therapy). During FLC monotherapy, the proportion of resistant colonies in the CSF increased during the first 2 weeks of treatment. In contrast, no resistant subpopulation was detectable in CSF by day 14 in those receiving a combination of FLC and 5FC. Genomic analysis revealed high rates of aneuploidy in heteroresistant colonies as well as in relapse isolates, with chromosome 1 (Chr1) disomy predominating. This is apparently due to the presence on Chr1 of ERG11, which is the FLC drug target, and AFR1, which encodes a drug efflux pump. In vitro efflux levels positively correlated with the level of heteroresistance.
Our findings demonstrate for what we believe is the first time the presence and emergence of aneuploidy-driven FLC heteroresistance in human CM, association of efflux levels with heteroresistance, and the successful suppression of heteroresistance with 5FC/FLC combination therapy.
This work was supported by the Wellcome Trust Strategic Award for Medical Mycology and Fungal Immunology 097377/Z/11/Z and the Daniel Turnberg Travel Fellowship.
Journal Article
Comparison of performances of laboratory methods in diagnosing pulmonary cryptococcosis in 1508 patients having lung biopsy tissues collected: a 6-year retrospective study
2024
PurposeThe diagnosis of pulmonary cryptococcosis (PC) remains challenging, particularly in patients presenting with lobar or patchy consolidation on chest radiographs. Biopsies are sometimes performed for histopathologic examination and microbiological culture to differentiate infections, including PC, from lung cancers. However, to date, the clinical value of small biopsy samples and their reasonable processing methods for detecting Cryptococcus are rarely evaluated. Furthermore, the cryptococcal antigen (CrAg) test has been widely used in cryptococcosis diagnosis due to its high specificity. This 6-year retrospective study aimed to assess the efficacy of four tests commonly used for detecting Cryptococcus in the diagnosis of pulmonary cryptococcosis, and reveal that the combination of 2 or 3 methods would raise diagnosis sensitivity.MethodsThe results of CrAg test, histopathologic examination and routine cryptococcal culture of sputum/bronchoalveolar lavage fluid (BALF) were collected from hospitalized patients between June 2019 to May 2024. Additionally, the results of 4 above-mentioned methods were analyzed to compare their effectiveness in PC diagnosis.ResultsAmong 1508 patients whose biopsy specimens were sent for pathogen detection, 63 PC cases were diagnosed, and 24 C. neoformans strains were cultivated using the Myco/F Lytic culture, which was more than those by sputum/BALF culture (9 strains). CrAg was positive in 82.5% (52/63) PC patients and remained the most sensitive method. The combination of CrAg and biopsy culture will increase the overall diagnostic yield to 95.2% (60/63).ConclusionsIn summary, for those having biopsy tissue collected, the combination of CrAg and biopsy culture using Myco/F could effectively identify most PC cases.
Journal Article
Microevolution of serial clinical isolates of Cryptococcus neoformans var. grubii and C. gattii
by
Jones, Alexander
,
Tenor, Jennifer L.
,
Chen, Yuan
in
Acquired immune deficiency syndrome
,
Adaptation
,
Adaptation, Biological
2017
The pathogenic species of Cryptococcus are a major cause of mortality owing to severe infections in immunocompromised as well as immunocompetent individuals. Although antifungal treatment is usually effective, many patients relapse after treatment, and in such cases, comparative analyses of the genomes of incident and relapse isolates may reveal evidence of determinative, microevolutionary changes within the host. Here, we analyzed serial isolates cultured from cerebrospinal fluid specimens of 18 South African patients with recurrent cryptococcal meningitis. The time between collection of the incident isolates and collection of the relapse isolates ranged from 124 days to 290 days, and the analyses revealed that, during this period within the patients, the isolates underwent several genetic and phenotypic changes. Considering the vast genetic diversity of cryptococcal isolates in sub-Saharan Africa, it was not surprising to find that the relapse isolates had acquired different genetic and correlative phenotypic changes. They exhibited various mechanisms for enhancing virulence, such as growth at 39°C, adaptation to stress, and capsule production; a remarkable amplification of ERG11 at the native and unlinked locus may provide stable resistance to fluconazole. Our data provide a deeper understanding of the microevolution of Cryptococcus species under pressure from antifungal chemotherapy and host immune responses. This investigation clearly suggests a promising strategy to identify novel targets for improved diagnosis, therapy, and prognosis. IMPORTANCE Opportunistic infections caused by species of the pathogenic yeast Cryptococcus lead to chronic meningoencephalitis and continue to ravage thousands of patients with HIV/AIDS. Despite receiving antifungal treatment, over 10% of patients develop recurrent disease. In this study, we collected isolates of Cryptococcus from cerebrospinal fluid specimens of 18 patients at the time of their diagnosis and when they relapsed several months later. We then sequenced and compared the genomic DNAs of each pair of initial and relapse isolates. We also tested the isolates for several key properties related to cryptococcal virulence as well as for their susceptibility to the antifungal drug fluconazole. These analyses revealed that the relapsing isolates manifested multiple genetic and chromosomal changes that affected a variety of genes implicated in the pathogenicity of Cryptococcus or resistance to fluconazole. This application of comparative genomics to serial clinical isolates provides a blueprint for identifying the mechanisms whereby pathogenic microbes adapt within patients to prolong disease. Opportunistic infections caused by species of the pathogenic yeast Cryptococcus lead to chronic meningoencephalitis and continue to ravage thousands of patients with HIV/AIDS. Despite receiving antifungal treatment, over 10% of patients develop recurrent disease. In this study, we collected isolates of Cryptococcus from cerebrospinal fluid specimens of 18 patients at the time of their diagnosis and when they relapsed several months later. We then sequenced and compared the genomic DNAs of each pair of initial and relapse isolates. We also tested the isolates for several key properties related to cryptococcal virulence as well as for their susceptibility to the antifungal drug fluconazole. These analyses revealed that the relapsing isolates manifested multiple genetic and chromosomal changes that affected a variety of genes implicated in the pathogenicity of Cryptococcus or resistance to fluconazole. This application of comparative genomics to serial clinical isolates provides a blueprint for identifying the mechanisms whereby pathogenic microbes adapt within patients to prolong disease.
Journal Article
Adjunctive Dexamethasone in HIV-Associated Cryptococcal Meningitis
by
Mwinjiwa, Edson
,
Day, Jeremy N
,
Phimmasone, Prasith
in
Adult
,
AIDS-Related Opportunistic Infections - drug therapy
,
AIDS-Related Opportunistic Infections - mortality
2016
The role of glucocorticoids in the treatment of bacterial or fungal meningitis is controversial. In this trial, adjunctive dexamethasone therapy in patients with HIV-associated cryptococcal meningitis did not confer a benefit and was associated with increased adverse events.
Cryptococcal meningitis associated with human immunodeficiency virus (HIV) infection is estimated to cause more than 600,000 deaths each year, the vast majority in sub-Saharan Africa and in South and Southeast Asia.
1
Among patients receiving combination antifungal therapy with amphotericin B and either flucytosine or fluconazole, mortality remains more than 30% at 10 weeks, and survivors often have substantial disability.
2
,
3
There is a pressing need to improve outcomes. However, no new anticryptococcal agents are currently close to approval for clinical use, so innovative strategies are needed.
Adjunctive treatments, such as glucocorticoids, have shown some benefit in central nervous system (CNS) . . .
Journal Article
Multilocus sequence typing (MLST) and M13 PCR fingerprinting revealed heterogeneity amongst Cryptococcus species obtained from Italian veterinary isolates
2014
Cryptococcosis represents a fungal disease acquired from the environment with animals serving as host sentinels for human exposure. The aim of this study was to investigate the genetic characteristics of Cryptococcus isolates from veterinary sources (cats, dogs and birds) to understand their epidemiology and the genetic variability of the casual isolates. Mating‐type PCR in connection with MLST analysis using the ISHAM consensus MLST scheme for the C. neoformans/C. gattii species complex was used to genotype 17 C. neoformans isolates. In the absence of an MLST typing scheme Cryptococcus adeliensis, C. albidus, C. aureus, C. carnescens, C. laurentii, C. magnus and C. uniguttulatus strains were typed using M13 PCR fingerprinting. All C. neoformans isolates were MATα mating type, but hybrids possessed αADa and aADα mating and serotypes. Two C. neoformans molecular types VNI, VNIV and VNIII and VNII/VNIV hybrids were identified. Amongst the 66 non‐C. neoformans strains investigated 55 M13 PCR fingerprinting types were identified. The wide variety of MLST types of C. neoformans and the occurrence of αADa and aADα hybrids in our study supports the notion of genetic recombination in the area studied. The heterogeneity of the non‐C. neoformans isolates remains open to further investigations and should be taken into consideration when identifying emergent pathogens.
Journal Article