Prevalence, Genetic Structure, and Antifungal Susceptibility of the Cryptococcus neoformans/C. gattii Species Complex Strains Collected from the Arboreal Niche in Poland

Fungi belonging to the Cryptococcus neoformans/C. gattii species complex (CNGSC) are etiological agents of serious and not infrequently fatal infections in both humans and animals. Trees are the main ecological niche and source of potential exposition concerning these pathogens. With regard to epidemiology of cryptococcosis, various surveys were performed worldwide, enabling the establishment of a map of distribution and genetic structure of the arboreal population of the CNGSC. However, there are regions, among them Central and Eastern Europe, in which the data are lacking. The present study shows the results of such an environmental study performed in Wrocław, Poland. The CNGSC strains were detected in 2.2% of the tested trees belonging to four genera. The obtained pathogen population consisted exclusively of C. neoformans, represented by both the major molecular type VNI and VNIV. Within the tested group of isolates, resistance to commonly used antimycotics was not found, except for 5-fluorocytosine, in which about 5% of the strains were classified as a non-wild type.

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Multicenter Study of Isavuconazole MIC Distributions and Epidemiological Cutoff Values for the Cryptococcus neoformans-Cryptococcus gattii Species Complex Using the CLSI M27-A3 Broth Microdilution Method

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04055-14 ◽

2014 ◽

Vol 59 (1) ◽

pp. 666-668 ◽

Cited By ~ 39

Author(s):

A. Espinel-Ingroff ◽

A. Chowdhary ◽

G. M. Gonzalez ◽

J. Guinea ◽

F. Hagen ◽

...

Keyword(s):

Cryptococcus Neoformans ◽

Multicenter Study ◽

Species Complex ◽

Cryptococcus Gattii ◽

Broth Microdilution ◽

Wild Type ◽

Content Type ◽

Microdilution Method ◽

Cutoff Values ◽

Broth Microdilution Method

ABSTRACTEpidemiological cutoff values (ECVs) of isavuconazole are not available forCryptococcusspp. The isavuconazole ECVs based on wild-type (WT) MIC distributions for 438Cryptococcus neoformansnongenotyped isolates, 870 isolates of genotype VNI, and 406Cryptococcus gattiiisolates from six laboratories and different geographical areas were 0.06, 0.12, and 0.25 μg/ml, respectively. These ECVs may aid in detecting non-WT isolates with reduced susceptibilities to isavuconazole.

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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

Journal of Fungi ◽

10.3390/jof7040282 ◽

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.

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In VitroActivity of Isavuconazole against Opportunistic Fungal Pathogens from Two Mycology Reference Laboratories

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01230-18 ◽

2018 ◽

Vol 62 (10) ◽

Cited By ~ 17

Author(s):

Michael A. Pfaller ◽

Paul R. Rhomberg ◽

Nathan P. Wiederhold ◽

Connie Gibas ◽

Carmita Sanders ◽

...

Keyword(s):

Species Complex ◽

Fungal Pathogens ◽

Antifungal Agents ◽

Antifungal Susceptibility ◽

Wild Type ◽

Content Type ◽

Excellent Activity ◽

Comparable Activity ◽

Yeasts And Molds ◽

Susceptibility Patterns

ABSTRACTMonitoring antifungal susceptibility patterns for new and established antifungal agents seems prudent given the increasing prevalence of uncommon species associated with higher antifungal resistance. We evaluated the activity of isavuconazole against 4,856 invasive yeasts and molds collected worldwide. The 4,856 clinical fungal isolates, including 2,351Candidaspecies isolates, 97 non-Candidayeasts, 1,972Aspergillusspecies isolates, and 361 non-Aspergillusmolds, including 292Mucoralesisolates collected in 2015 to 2016, were tested using CLSI methods. The MIC values for isavuconazole versusAspergillusranged from 0.06 to ≥16 μg/ml. The modal MIC for isavuconazole was 0.5 μg/ml (range, 0.25 [A. nidulansandA. terreusspecies complex] to 4 μg/ml [A. calidoustusandA. tubingensis]). EightA. fumigatusisolates had elevated isavuconazole MIC values at ≥8 μg/ml (non-wild type). Isavuconazole showed comparable activity to itraconazole against theMucorales. The lowest modal isavuconazole MIC values were seen forRhizopusspp.,R. arrhizusvar.arrhizus, andR. microsporus(all 1 μg/ml).Candidaspecies isolates were inhibited by ≤0.25 μg/ml of isavuconazole (range, 96.1% [C. lusitaniae] to 100.0% [C. albicans,C. dubliniensis,C. kefyr, andC. orthopsilosis]). MIC values were ≤1 μg/ml for 95.5% ofC. glabrataisolates and 100.0% ofC. kruseiisolates. Isavuconazole was active against the non-Candidayeasts, includingCryptococcus neoformans(100.0% at ≤0.5 μg/ml). Isavuconazole exhibited excellent activity against most species ofCandidaandAspergillus. Isavuconazole was comparable to posaconazole and voriconazole against the less common yeasts and molds. Isavuconazole was generally less active than posaconazole and more active than voriconazole against the 292Mucoralesisolates. We confirm the potentially useful activity of isavuconazole against species ofRhizopusas determined by CLSI methods.

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

Journal of Medical Microbiology ◽

10.1099/jmm.0.001440 ◽

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.

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

Journal of Fungi ◽

10.3390/jof7050338 ◽

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.

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cyp51A Mutations, Extrolite Profiles, and Antifungal Susceptibility in Clinical and Environmental Isolates of the Aspergillus viridinutans Species Complex

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00632-19 ◽

2019 ◽

Vol 63 (11) ◽

Cited By ~ 3

Author(s):

Jessica J. Talbot ◽

Jens C. Frisvad ◽

Jacques F. Meis ◽

Ferry Hagen ◽

Paul E. Verweij ◽

...

Keyword(s):

Species Complex ◽

Antifungal Susceptibility ◽

Gene Mutations ◽

Azole Resistance ◽

Wild Type ◽

Environmental Isolates ◽

Content Type ◽

The Past ◽

Agar Plug ◽

Very High

ABSTRACT The past decade has seen an increase in aspergillosis in humans and animals due to Aspergillus viridinutans species complex members. Azole resistance is common to these infections, carrying a poor prognosis. cyp51A gene mutations are the main cause of acquired azole resistance in Aspergillus fumigatus. This study aimed to determine if the azole-resistant phenotype in A. viridinutans complex members is associated with cyp51A mutations or extrolite profiles. The cyp51A gene of clinical and environmental isolates was amplified using novel primers, antifungal susceptibility was tested using the Clinical and Laboratory Standards Institute methodology, and extrolite profiling was performed using agar plug extraction. Very high azole MICs were detected in 84% of the isolates (31/37). The MICs of the newer antifungals luliconazole and olorofim (F901318) were low for all isolates. cyp51A sequences revealed 113 nonsynonymous mutations compared to the sequence of wild-type A. fumigatus. M172A/V and D255G, previously associated with A. fumigatus azole resistance, were common among all isolates but were not correlated with azole MICs. Two environmental isolates with nonsusceptibility to itraconazole and high MICs of voriconazole and isavuconazole harbored G138C, previously associated with azole-resistant A. fumigatus. Some novel mutations were identified only among isolates with high azole MICs. However, cyp51A homology modeling did not cause a significant protein structure change for these mutations. There was no correlation between extrolite patterns and susceptibility. For A. viridinutans complex isolates, cyp51A mutations and the extrolites that they produced were not major causes of antifungal resistance. Luliconazole and olorofim show promise for treating azole-resistant infections caused by these cryptic species.

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Molecular epidemiology and antifungal susceptibility profiles of clinical Cryptococcus neoformans/Cryptococcus gattii species complex

Journal of Medical Microbiology ◽

10.1099/jmm.0.001101 ◽

2020 ◽

Vol 69 (1) ◽

pp. 72-81 ◽

Cited By ~ 5

Author(s):

Zainab Bandalizadeh ◽

Tahereh Shokohi ◽

Hamid Badali ◽

Mahdi Abastabar ◽

Farhang Babamahmoudi ◽

...

Keyword(s):

Molecular Epidemiology ◽

Cryptococcus Neoformans ◽

Species Complex ◽

Antifungal Susceptibility ◽

Cryptococcus Gattii ◽

Susceptibility Profiles

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A case-series of bloodstream infections caused by the Meyerozyma guilliermondii species complex at a reference center of oncology in Brazil

Medical Mycology ◽

10.1093/mmy/myaa044 ◽

2020 ◽

Author(s):

Alessandra Leal Silva Chaves ◽

Luciana Trilles ◽

Gabriela Machado Alves ◽

Maria Helena Galdino Figueiredo-Carvalho ◽

Fábio Brito-Santos ◽

...

Keyword(s):

Candida Species ◽

Poor Prognosis ◽

Species Complex ◽

Antifungal Susceptibility ◽

Case Series ◽

Bloodstream Infections ◽

Its2 Region ◽

Wild Type ◽

Reference Center ◽

Meyerozyma Guilliermondii

Abstract Bloodstream infections (BSI) caused by Candida species are the fourth cause of healthcare associated infections worldwide. Non-albicans Candida species emerged in the last decades as agents of serious diseases. In this study, clinical and microbiological aspects of six patients with BSI due to the Meyerozyma (Candida) guilliermondii species complex from an oncology reference center in Brazil, were evaluated. To describe demographic and clinical characteristics, medical records of the patients were reviewed. Molecular identification of the isolates was performed by ITS1-5.8S-ITS2 region sequencing. Antifungal susceptibility was evaluated by the EUCAST method and the minimal inhibitory concentrations (MIC) assessed according to the epidemiological cutoff values. Virulence associated phenotypes of the isolates were also studied. Ten isolates from the six patients were evaluated. Five of them were identified as Meyerozyma guilliermondii and the others as Meyerozyma caribbica. One patient was infected with two M. caribbica isolates with different genetic backgrounds. High MICs were observed for fluconazole and echinocandins. Non-wild type isolates to voriconazole appeared in one patient previously treated with this azole. Additionally, two patients survived, despite infected with non-wild type strains for fluconazole and treated with this drug. All isolates produced hemolysin, which was not associated with a poor prognosis, and none produced phospholipases. Aspartic proteases, phytase, and esterase were detected in a few isolates. This study shows the reduced antifungal susceptibility and a variable production of virulence-related enzymes by Meyerozyma spp. In addition, it highlights the poor prognosis of neutropenic patients with BSI caused by this emerging species complex. Lay Abstract Our manuscript describes demographic, clinical and microbiological characteristics of patients with bloodstream infection by the Meyerozyma guilliermondii species complex at a reference center in oncology in Brazil.

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Molecular typing and antifungal susceptibility of clinical and environmental Cryptococcus neoformans species complex isolates in Goiania, Brazil

Mycoses ◽

10.1111/j.1439-0507.2008.01662.x ◽

2010 ◽

Vol 53 (1) ◽

pp. 62-67 ◽

Cited By ~ 28

Author(s):

L. K. H. Souza ◽

A. H. Souza Junior ◽

C. R. Costa ◽

J. Faganello ◽

M. H. Vainstein ◽

...

Keyword(s):

Cryptococcus Neoformans ◽

Molecular Typing ◽

Species Complex ◽

Antifungal Susceptibility

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Cryptococcus neoformans-Cryptococcus gattii Species Complex: an International Study of Wild-Type Susceptibility Endpoint Distributions and Epidemiological Cutoff Values for Amphotericin B and Flucytosine

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.06252-11 ◽

2012 ◽

Vol 56 (6) ◽

pp. 3107-3113 ◽

Cited By ~ 87

Author(s):

A. Espinel-Ingroff ◽

A. Chowdhary ◽

M. Cuenca-Estrella ◽

A. Fothergill ◽

J. Fuller ◽

...

Keyword(s):

Cryptococcus Neoformans ◽

Amphotericin B ◽

Species Complex ◽

Acquired Resistance ◽

International Study ◽

Resistance Mechanisms ◽

Cryptococcus Gattii ◽

Wild Type ◽

Content Type ◽

Cutoff Values

ABSTRACTClinical breakpoints (CBPs) are not available for theCryptococcus neoformans-Cryptococcus gattiispecies complex. MIC distributions were constructed for the wild type (WT) to establish epidemiologic cutoff values (ECVs) forC. neoformansandC. gattiiversus amphotericin B and flucytosine. A total of 3,590 amphotericin B and 3,045 flucytosine CLSI MICs forC. neoformans(including 1,002 VNI isolates and 8 to 39 VNII, VNIII, and VNIV isolates) and 985 and 853 MICs forC. gattii, respectively (including 42 to 259 VGI, VGII, VGIII, and VGIV isolates), were gathered in 9 to 16 (amphotericin B) and 8 to 13 (flucytosine) laboratories (Europe, United States, Australia, Brazil, Canada, India, and South Africa) and aggregated for the analyses. Additionally, 442 amphotericin B and 313 flucytosine MICs measured by using CLSI-YNB medium instead of CLSI-RPMI medium and 237 Etest amphotericin B MICs forC. neoformanswere evaluated. CLSI-RPMI ECVs for distributions originating in ≥3 laboratories (with the percentages of isolates for which MICs were less than or equal to ECVs given in parentheses) were as follows: for amphotericin B, 0.5 μg/ml forC. neoformansVNI (97.2%) andC. gattiiVGI and VGIIa (99.2 and 97.5%, respectively) and 1 μg/ml forC. neoformans(98.5%) andC. gattiinontyped (100%) and VGII (99.2%) isolates; for flucytosine, 4 μg/ml forC. gattiinontyped (96.4%) and VGI (95.7%) isolates, 8 μg/ml for VNI (96.6%) isolates, and 16 μg/ml forC. neoformansnontyped (98.6%) andC. gattiiVGII (97.1%) isolates. Other molecular types had apparent variations in MIC distributions, but the number of laboratories contributing data was too low to allow us to ascertain that the differences were due to factors other than assay variation. ECVs may aid in the detection of isolates with acquired resistance mechanisms.

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