Molecular types of Cryptococcus neoformans and Cryptococcus gattii in Western Australia and correlation with antifungal susceptibility

2019 ◽  
Vol 57 (8) ◽  
pp. 1004-1010 ◽  
Author(s):  
Gar-hing Andrew Lee ◽  
Ian Arthur ◽  
Adam Merritt ◽  
Michael Leung
Keyword(s):  
Cryptococcus Neoformans ◽  
Antifungal Agents ◽  
Geometric Mean ◽  
Antifungal Susceptibility ◽  
Cryptococcus Gattii ◽  
Molecular Type ◽  
Australian Population ◽  
Worldwide Distribution ◽  
Species Complexes ◽  
Western Australian

AbstractCryptococcus neoformans and Cryptococcus gattii species complexes have a worldwide distribution; however, there is geographical variation in the prevalence of different molecular types. Additionally, antifungal susceptibility differences between molecular types have been demonstrated. This study investigates the distribution of cryptococcal molecular types among human clinical isolates over a 10-year period from a Western Australian population. Molecular type was determined based on polymorphisms in the phospholipase gene locus identified through amplification and sequencing. Minimum inhibitory concentrations (MICs) were identified for fluconazole, 5-fluorocytosine, posaconazole, itraconazole, voriconazole, and amphotericin B. Most isolates were C. neoformans complex (42) of which over half were molecular type VNI (22) followed by VNII (20). Among the remaining C. gattii complex (13) the majority were VGI (11) with VGII (2) uncommonly found. All isolates demonstrated low MICs to antifungal agents including fluconazole. Geometric mean MIC values against 5-fluorocytosine for VNI (1.741 mg/l) were significantly higher than those for VGI (0.47 mg/l, P = .002). Similarly fluconazole geometric mean MICs against fluconazole for VNI (2.3 mg/l) were significantly higher than VNII (0.87 mg/l, P = .036). These data reveal the presence of four molecular types (VNI, VNII, VGI and VGII) within clinical Western Australian cryptococcal isolates and, while elevated antifungal MICs were not encountered, significant molecular type dependent differences in susceptibility were found.

scholarly journals Cryptococcus neoformans and Cryptococcus gattii Species Complexes in Latin America: A Map of Molecular Types, Genotypic Diversity, and Antifungal Susceptibility as Reported by the Latin American Cryptococcal Study Group

2021 ◽  
Vol 7 (4) ◽  
pp. 282
Author(s):  
Carolina Firacative ◽  
Wieland Meyer ◽  
Elizabeth Castañeda
Keyword(s):  
Latin America ◽  
Cryptococcus Neoformans ◽  
Latin American ◽  
Antifungal Susceptibility ◽  
Genotypic Diversity ◽  
Cryptococcus Gattii ◽  
Study Group ◽  
Molecular Type ◽  
Infected People ◽  
Species Complexes

Cryptococcosis, a potentially fatal mycosis, is caused by members of the Cryptococcus neoformans and Cryptococcus gattii species complexes. In Latin America, cryptococcal meningitis is still an important health threat with a significant clinical burden. Analysis of publicly available molecular data from 5686 clinical, environmental, and veterinary cryptococcal isolates from member countries of the Latin American Cryptococcal Study Group showed that, as worldwide, C. neoformans molecular type VNI is the most common cause of cryptococcosis (76.01%) in HIV-infected people, followed by C. gattii molecular type VGII (12.37%), affecting mostly otherwise healthy hosts. These two molecular types also predominate in the environment (68.60% for VNI and 20.70% for VGII). Among the scarce number of veterinary cases, VGII is the predominant molecular type (73.68%). Multilocus sequence typing analysis showed that, in Latin America, the C. neoformans population is less diverse than the C. gattii population (D of 0.7104 vs. 0.9755). Analysis of antifungal susceptibility data showed the presence of non-wild-type VNI, VGI, VGII, and VGIII isolates in the region. Overall, the data presented herein summarize the progress that has been made towards the molecular epidemiology of cryptococcal isolates in Latin America, contributing to the characterization of the genetic diversity and antifungal susceptibility of these globally spreading pathogenic yeasts.

scholarly journals Environmental Status of Cryptococcus neoformans and Cryptococcus gattii in Colombia

2021 ◽  
Vol 7 (6) ◽  
pp. 410
Author(s):  
Briggith-Nathalia Serna-Espinosa ◽  
Diomedes Guzmán-Sanabria ◽  
Maribel Forero-Castro ◽  
Patricia Escandón ◽  
Zilpa Adriana Sánchez-Quitian
Keyword(s):  
Cryptococcus Neoformans ◽  
Species Complex ◽  
Columba Livia ◽  
Systematic Investigation ◽  
Cryptococcus Gattii ◽  
Eucalyptus Species ◽  
Environmental Niche ◽  
Worldwide Distribution ◽  
Bird Droppings ◽  
The Central Nervous System

The genus Cryptococcus comprises more than 80 species, including C. neoformans and C. gattii, which are pathogenic to humans, mainly affecting the central nervous system. The two species differ in geographic distribution and environmental niche. C. neoformans has a worldwide distribution and is often isolated from bird droppings. On the contrary, C. gattii is reported in tropical and subtropical regions and is associated with Eucalyptus species. This review aims to describe the distribution of environmental isolates of the Cryptococcus neoformans species complex and the Cryptococcus gattii species complex in Colombia. A systematic investigation was carried out using different databases, excluding studies of clinical isolates reported in the country. The complex of the species of C. gattii is recovered mainly from trees of the genus Eucalyptus spp., while the complex of the species of C. neoformans is recovered mainly from avian excrement, primarily Columba livia (pigeons) excrement. In addition, greater positivity was found at high levels of relative humidity. Likewise, an association was observed between the presence of the fungus in places with little insolation and cold or temperate temperatures compared to regions with high temperatures.

scholarly journals The Investigational Fungal Cyp51 Inhibitor VT-1129 Demonstrates PotentIn VitroActivity against Cryptococcus neoformans and Cryptococcus gattii

2016 ◽  
Vol 60 (4) ◽  
pp. 2528-2531 ◽  
Author(s):  
Shawn R. Lockhart ◽  
Annette W. Fothergill ◽  
Naureen Iqbal ◽  
Carol B. Bolden ◽  
Nina T. Grossman ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Geometric Mean ◽  
Cryptococcus Gattii ◽  
The Novel ◽  
Content Type ◽  
Large Panel

ABSTRACTThein vitroactivities of the novel fungal Cyp51 inhibitor VT-1129 were evaluated against a large panel ofCryptococcus neoformansandCryptococcus gattiiisolates. VT-1129 demonstrated potent activities against bothCryptococcusspecies as demonstrated by low MIC50and MIC90values. ForC. gattii, thein vitropotency was maintained against all genotypes. In addition, significantly lower geometric mean MICs were observed for VT-1129 than for fluconazole againstC. neoformans, including isolates with reduced fluconazole susceptibility.

scholarly journals Comparison of the Sensititre YeastOne and CLSI M38-A2 Microdilution Methods in Determining the Activity of Amphotericin B, Itraconazole, Voriconazole, and Posaconazole against Aspergillus Species

2018 ◽  
Vol 56 (10) ◽  
Author(s):  
Hsuan-Chen Wang ◽  
Ming-I Hsieh ◽  
Pui-Ching Choi ◽  
Chi-Jung Wu
Keyword(s):  
Aspergillus Fumigatus ◽  
Amphotericin B ◽  
Antifungal Agents ◽  
Susceptibility Testing ◽  
Geometric Mean ◽  
Antifungal Susceptibility ◽  
Reference Method ◽  
Aspergillus Species ◽  
Broth Microdilution ◽  
Content Type

ABSTRACT This study compared the YeastOne and reference CLSI M38-A2 broth microdilution methods for antifungal susceptibility testing of Aspergillus species. The MICs of antifungal agents were determined for 100 Aspergillus isolates, including 54 Aspergillus fumigatus (24 TR34/L98H isolates), 23 A. flavus, 13 A. terreus, and 10 A. niger isolates. The overall agreement (within 2 2-fold dilutions) between the two methods was 100%, 95%, 92%, and 90% for voriconazole, posaconazole, itraconazole, and amphotericin B, respectively. The voriconazole geometric mean (GM) MICs were nearly identical for all isolates using both methods, whereas the itraconazole and posaconazole GM MICs obtained using the YeastOne method were approximately 1 dilution lower than those obtained using the reference method. In contrast, the amphotericin B GM MIC obtained using the YeastOne method was 3.3-fold higher than that observed using the reference method. For the 24 A. fumigatus TR34/L98H isolates assayed, the categorical agreement (classified according to the CLSI epidemiological cutoff values) was 100%, 87.5%, and 83.3% for itraconazole, voriconazole, and posaconazole, respectively. For four A. niger isolates, the itraconazole MICs were >8 μg/ml using the M38-A2 method due to trailing growth, whereas the corresponding itraconazole MICs obtained using the YeastOne method were all ≤0.25 μg/ml without trailing growth. These data suggest that the YeastOne method can be used as an alternative for azole susceptibility testing of Aspergillus species and for detecting the A. fumigatus TR34/L98H isolates but that this method fails to detect A. niger isolates exhibiting trailing growth with itraconazole. Additionally, for isolates with azole MICs that approach or that are at susceptibility breakpoints or with high amphotericin B MICs detected using the YeastOne method, further MIC confirmation using the reference CLSI method is needed.

Clinical and microbiological characteristics of Cryptococcus gattii isolated from China

2020 ◽  
Author(s):  
Liang Jin ◽  
Jingrong Cao ◽  
Xinying Xue ◽  
Hua Wu ◽  
Lifeng Wang ◽  
...  
Keyword(s):  
Antifungal Agents ◽  
Antifungal Susceptibility ◽  
The United States ◽  
Cryptococcus Gattii ◽  
Clinical Isolates ◽  
Strain Identification ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Significant Difference ◽  
Tof Ms

Abstract Background: Infection, even outbreak, caused by Cryptococcus gattii (C. gattii ) has been reported in Canada and the United States, but there were sparsely-reported cases of C. gattii in China. Our interest in occurrence, clinical manifestation, laboratory identification and molecular characterization of Chinese C. gattii strains leads us to this research. Methods: A total of 254 clinical isolates primarily identified as Cryptococcus neoformans (C. neoformans ) were collected. VITEK 2 compact, canavanine glycine bromothymol blue (CGB) agar and Bruker Biotyper matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) were used for strain identification. Multi-locus sequence typing (MLST) was performed for genotyping. Antifungal susceptibility test was carried out with commercial kits of both ATB fungus 3 and Yeast one. Clinical information of patients was reviewed retrospectively. Label-free proteome technique was used to quantitatively analyze the differential proteins of C. gattii. Results: Out of 254 clinical isolates, we identified eight strains as C. gattii. MLST showed genotype VGI accounted for the most (6 / 8), the other two strains were genotype VGII（VGIIa and VGIIb respectively）with 3 specific spectra of molecular weight about 4342, 8686, 9611 Dalton by MALDI-TOF MS. The minimal inhibitory concentrations (MICs) of Fluconazole with Yeast one was 2～4 times higher than that with ATB fungus 3. Higher MICs of antifungal agents were exhibited against VGII strains than against VGI strains. C. gattii genotype VGII and VGI possessed 418 and 774 specific proteins respectively. Comparative proteome analysis showed that 180 proteins were highly expressed in C. gattii VGII and 329 proteins were highly expressed in C. gattii VGI. The enrichment of differentially expressed proteins between VGII and VGI was directed to Golgi complex.Conclusions: Infection by C. gattii in China might have been underestimated because of initial mis-identification. Genotype VGI was predominant but VGII was more resistant to antifungal agents. There was significant difference in protein expression profile between VGII and VGI C. gattii.

scholarly journals Comparison of in vitro susceptibility of different azoles agents against dermatophytes

2020 ◽  
Author(s):  
Jie Liu ◽  
Lanting Liu ◽  
Xiaoyun Liu ◽  
Bo Yu ◽  
Xiaoping Hu
Keyword(s):  
Antifungal Agents ◽  
Susceptibility Testing ◽  
Geometric Mean ◽  
Antifungal Susceptibility ◽  
Antifungal Resistance ◽  
Antifungal Susceptibility Testing ◽  
In Vitro Susceptibility

Abstract The research on antifungal resistance in dermatophytoses lags behind that on systemic mycose. Lack of datas of antifungal susceptibility testing in dermatophytoses is one reasion. 121 clinical dermatophytes isolates were tested against 6 azole antifungal agents according to the Clinical and Laboratory Standards Institute (CLSI) method. Geometric mean MIC of all isolates were in increasing order: isavuconazole (GM 0.06 mg/L), posaconazole (GM 0.10 mg/L), itraconazole (GM 0.22 mg/L), voriconazole (GM 0.32 mg/L), ketoconazole (GM 0.40 mg/L), fluconazole (GM 10.18 mg/L).

scholarly journals Multi-locus sequence typing reveals genotypic similarity in Nigerian Cryptococcus neoformans AFLP1/VNI of environmental and clinical origin

2021 ◽  
Vol 70 (10) ◽  
Author(s):  
Paul E. Chidebelu ◽  
Emeka I. Nweze ◽  
Jacques F. Meis ◽  
Massimo Cogliati ◽  
Ferry Hagen
Keyword(s):  
Cryptococcus Neoformans ◽  
Antifungal Susceptibility ◽  
Epidemiological Data ◽  
Clinical Samples ◽  
Molecular Type ◽  
Aids Patients ◽  
Susceptible Population ◽  
South Eastern ◽  
Pigeon Droppings ◽  
Hiv Aids

Introduction Pigeon droppings are among the major environmental sources of Cryptococcus neoformans AFLP1/VNI, from where the organism infects susceptible humans and animals resulting in cryptococcosis. Until now, C. neoformans AFLP1B/VNII was the only molecular type reported in Nigeria. Effective clinical treatment of this infection has occasionally been stymied by the emergence of antifungal non-susceptible, and resistant strains of C. neoformans AFLP1/VNI. Hypothesis/Gap Statement Pigeon droppings harbour C. neoformans and HIV/AIDS patients are among the susceptible population to develop cryptococcal infection. Epidemiological data on cryptococcal prevalence is limited in Nigeria. Aim To investigate the environmental prevalence of C. neoformans in South-eastern Nigeria and compare the isolates with other lineages by using molecular and microbiological tools. Methodology A total of 500 pigeon droppings and 300 blood samples of HIV/AIDS patients were collected, respectively, from five market squares and three tertiary healthcare centres within the Nsukka area of South-eastern Nigeria. The antifungal susceptibility of the C. neoformans isolates to amphotericin B, fluconazole, 5-fluorocytosine, itraconazole, voriconazole, posaconazole, and isavuconazole was investigated based on the CLSI M27-A3 protocol. Yeasts were identified by MALDI-TOF MS, thereafter Cryptococcus MLST was performed according to the International Society for Human and Animal Mycology (ISHAM) consensus scheme. Results C. neoformans was recovered from 6 (1.2 %) pigeon droppings and 6 (2 %) blood cultures of HIV/AIDS patients. Molecular analyses indicated that all cryptococcal isolates belong to serotype A and the AFLP1/VNI molecular type with sequence type (ST)32. Infection with C. neoformans was independent of sex and age of the patients investigated. All C. neoformans isolates were susceptible to the seven antifungal agents. Conclusion This is the first report on the prevalence of C. neoformans AFLP1/VNI (ST32) in environmental and clinical samples from Nigeria. The antifungal susceptibility indicates that antifungal resistance by C. neoformans is yet a rare occurrence in Nigeria.

scholarly journals Genotype, Antifungal Susceptibility, and Virulence of Clinical South African Cryptococcus neoformans Strains from National Surveillance, 2005–2009

2021 ◽  
Vol 7 (5) ◽  
pp. 338
Author(s):  
Serisha D. Naicker ◽  
Rindidzani E. Magobo ◽  
Tsidiso G. Maphanga ◽  
Carolina Firacative ◽  
Erika van Schalkwyk ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Cryptococcus Neoformans ◽  
South African ◽  
Reference Strain ◽  
Galleria Mellonella ◽  
Antifungal Susceptibility ◽  
National Surveillance ◽  
Molecular Type ◽  
African Patients ◽  
Sequence Types

In South Africa, Cryptococcus neoformans is the most common cause of adult meningitis. We performed multi locus sequence typing and fluconazole susceptibility testing of clinical C. neoformans isolates collected from 251 South African patients with cryptococcosis through national surveillance from 2005 to 2009. We examined the association between clinical characteristics of patients and genotype, and the effect of genotype on in-hospital mortality. We performed whole genome phylogenetic analysis of fifteen C. neoformans isolates with the molecular type VNB and tested their virulence in a Galleria mellonella model. Most isolates had the molecular type VNI (206/251, 82%), followed by VNII (25/251, 10%), VNB (15/251, 6%), and VNIV (5/251, 2%); 67 sequence types were identified. There were no differences in fluconazole minimum inhibitory concentration (MIC) values among molecular types and the majority of strains had low MIC values (MIC50 of 1 µg/mL and MIC90 of 4 µg/mL). Males were almost twice as likely of being infected with a non-VNI genotype (adjusted odds ratio [OR]: 1.65, 95% confidence interval [CI]: 0.25–10.99; p = 0.61). Compared to patients infected with a VNI genotype, those with a non-VNI genotype had a 50% reduced adjusted odds of dying in hospital (95% CI: 0.03–7.57; p = 0.62). However, for both these analyses, our estimates had wide confidence intervals spanning 1 with large p-values. Fifteen VNB strains were not as virulent in a G. mellonella larval model as the H99 reference strain. A majority of these VNB strains belonged to the VNBII clade and were very closely related by phylogenetic analysis.

Sign in / Sign up

Export Citation Format

Share Document