Article Figures & Data
Figures
- FIG 1
Rooted neighbor-joining tree inferred from the concatenated MLST typing scheme sequences (CAP59, GPD1, LAC1, SOD1, URA5, and PLB1 genes and IGS) of 10 strains of each major C. gattii molecular type rooted with the standard strains of the three major C. neoformans molecular types. Numbers on branches are bootstrap support values obtained from 1,000 pseudoreplicates using the program MEGA version 5.05. Numbers in the white boxes indicate estimated diversion times based on the 10 genetic concatenated loci (ACT1, LAC1, IDE1, ITS1/2, IGS, PLB1, RPB1, RPB2, TEF1, and URA5), generated with the program BEAST.
- FIG 2
Identification of the major molecular types within C. gattii. (A) PCR fingerprinting generated with the primer M13; (B) AFLP profiles generated with the 6-carboxyfluorescein (FAM) label AC+G kit; (C) PLB1 gene RFLP profiles identified via digestion with AvaI; (D) URA5 gene RFLP profiles identified via double digestion with Sau96I and HhaI; (E) PLB1 gene hyperbranched rolling-circle amplification; (F) MALDI-TOF MS profiles obtained from the reference strains of each major molecular type.
- FIG 3
Distribution of the four major molecular types of C. gattii identified among a total of 980 clinical/veterinary and environmental global isolates. Shown is the distribution of the four major molecular types of C. gattii, combining clinical/veterinary (n = 615) and environmental (n = 365) isolates (top) from North America (including Mexico) (n = 162), South America (n = 367), and Europe (n = 44) (middle) and from Africa (n = 64), Asia (n = 78), and Australasia (n = 265) (bottom).
- FIG 4
Global distribution of the four major molecular types of C. gattii, based on 980 isolates.
- FIG 5
Percentages of 256 clinical isolates obtained from immunocompetent and immunocompromised patients (HIV positive) and from patients with other risk factors per major molecular type, identified by URA5 RFLP analysis, PCR fingerprinting, or AFLP analysis, for which clinical data were available. Other risk factors are alcoholism, corticosteroid use, disorder T immunity, diabetes, leukemia, systemic lupus erythematosus, transplant, and tumor.
- FIG 6
Chest X ray of a patient with a large mass lesion in the right lower lobe. Bronchoscopy and collection of bronchoalveolar lavage fluid showed multiple encapsulated yeasts upon cytological examination, and a culture grew Cryptococcus gattii. (Reprinted from reference 388 with permission of the publisher. Copyright 2013 UpToDate, Inc. [www.uptodate.com].)
- FIG 7
Computerized tomographic scan of brain showing a large mass lesion in the left cerebellar hemisphere (indicated by arrow). A provisional diagnosis of a cerebral neoplasm was made. Excision biopsy of the lesion showed encapsulated yeasts, and Cryptococcus gattii was isolated in culture.
Tables
- TABLE 1
Concordance of different schemes used for molecular typing of Cryptococcus gattii
C. gattii serotype PCR fingerprinting molecular type (40, 77) AFLP genotype (33) URA5 RFLP type (40) PLB1 RFLP type (41) ITS genotype (342) IGS genotype (31, 350) MLST type (43) B/C VGI AFLP4A/AFLP4B VGI (SH5) A5 ITS3/ITS7 4 VGI B/C VGII AFLP6 VGII (SH6) A6 ITS4 3 VGII B/C VGIII AFLP5A/AFLP5B/AFLP5C VGIII (SH7) A7 ITS5 5 VGIII B/C VGIV AFLP7 VGIV (SH8) A8 ITS6 6 VGIV - TABLE 2
Standard/reference strains for Cryptococcus gattii strain typing a
C. gattii PCR fingerprinting molecular type (reference) and AFLP genotype (reference) CBS strain designation ATCC strain designation FGS strain designation WM strain designation CMRVS strain designation Other strain designation(s) MAT type and serotype Description Reference(s) VGI (40) and AFLP4 (33) CBS 10078 ATCC MYA-4560 10419 WM 179 70298 Bryon, H33.1, MH56 αB 1993, Sydney, NSW, Australia; clinical, CSF, HIV negative; isolated by Sharon C.-A. Chen 40, 154 CBS 6289 ATCC 32269 WM 01.124 MUCL 30449, RV 20186, CBS 8273 aB 1966, Kinshasa, Congo; clinical, CSF; isolated by E. Gatti and R. Eeckels; type strain of C. neoformans var. gattii 199 CBS 10510 WM 276 TCS, SC1 αB 1993, Mt. Annan National Park, NSW, Australia; environmental, Eucalyptus tereticornis woody debris; isolated by Tania C. Sorrell and Sharon C.-A. Chen; genome sequence strain 40 VGII (40) and AFLP6 (22) CBS 10082 ATCC MYA-4561 10420 WM 178 70302 49435, Colter, IFM 50894 αB 1991, Sydney, NSW Australia; clinical, CSF, HIV negative; isolated by Sharon C.-A. Chen 40, 154 CBS 10514 WM 02.32 CDC R265 αB 2001, Duncan, Vancouver Island, BC, Canada; clinical, bronchial wash specimen; isolated by British Columbia CDC; highly virulent Vancouver Island outbreak strain of VGIIa; genome sequence strain 38 VGIII (40) and AFLP5 (22) CBS 10081 ATCC MYA-4562 10421 WM 175 70299 WM 161, E698, 689, TP 0689, D1.13H αB 1992, Blind Recreation Center/Park Boulevard UPAS Street, San Diego, CA, USA; environmental, Eucalyptus species woody debris; isolated by Tania Pfeiffer and David Ellis 40, 100 CBS 6955 ATCC 32608 10424 WM 01.125 DBVPG 6225, WM 2220, MUCL 30454, NIH 191, CBS 6916 aC Before 1970, San Fernando, CA, USA; clinical, CSF 2 VGIV (40) and AFLP7 (56) CBS 10101 ATCC MYA-4563 10422 WM 779 70300 King Cheetah, IFM 50896 αC 1994, Johannesburg, South Africa; veterinary, cheetah; isolated by Valerie Davis 40, 389 ↵a Adapted from reference 43.
- TABLE 3
Comparison of cellular functions and virulence of Cryptococcus gattii and Cryptococcus neoformans by using deletion mutants a
Gene(s) of interest, product Function Phenotype Required for virulence, model Reference(s) SOD1, superoxide dismutase Cytoplasmic antioxidant Required for production of virulence factors urease, PLB, and laccase in C. gattii but not C. neoformans Yes, in BALB/c mouse intravenous inoculation model and in A/JCr mouse inhalational model of C. neoformans 390 SOD2, superoxide dismutase Mitochondrial antioxidant Required for growth at 37°C in 20% but not in 1.3% oxygen Yes, for C. gattii BALB/c mouse inhalation and i.v. inoculation model; C. neoformans was not tested 391 TPS1 and TPS2, trehalose-6-phosphate synthase Trehalose biosynthesis; trehalose functions as an antioxidant and stress protectant Required for thermotolerance, capsule and melanin production, mating, and cell wall integrity in C. gattii and thermotolerance in C. neoformans Yes, for C. gattii Caenorhabditis elegans (worm) and A/JCr mouse inhalational models; TSP1 but not TSP2 is required for virulence in C. neoformans 392, 393 PKA1, cAMP-activated protein kinase A Signal transduction pathway regulator Required for capsule production in C. gattii and mating and capsule and melanin production in C. neoformans C. gattii was not tested; yes, for virulence of C. neoformans in BALB/c mouse inhalational model and immunosuppressed rabbit CSF inoculation model 394, 395 PKA2, cAMP-activated protein kinase A Signal transduction pathway regulator Required for mating and capsule and melanin production in C. gattii but not C. neoformans Not tested 394, 395 PLC1 Signal transduction pathway regulator Regulates growth at 37°C and melanin and PLB production in C. neoformans through the PKC/MAPK pathway (see below) Yes, in C. neoformans BALB/c mouse inhalational model 396 MPK1 Signal transduction pathway regulator Regulates melanin, capsule production, and cell wall integrity in C. gattii and thermotolerance and cell wall integrity at 37°C in C. neoformans Yes, in C. gattii (BALB/c inhalational model) and in C. neoformans i.v. DBA/2 complement-deficient mouse model 397 STE12α Transcription factor Regulates melanin, mating, and ecological fitness in C. gattii and mating and capsule size in C. neoformans Yes, in C. gattii but not C. neoformans 398, 399 GAT1 GATA transcription factor Regulates nitrogen utilization Yes, in C. gattii but not in C. neoformans BALB/c intrapharyngeal instillation model 400 CNA1, calcineurin catalytic subunit (A) Subunit of the heterodimer calcineurin, a Ca2+ calmodulin-activated serine-threonine-specific protein phosphatase In C. gattii, regulates thermotolerance (37°C) (strains differ) and is required for plasma membrane integrity, tolerance to fluconazole, and optimal growth in the presence of Ca2+ Li+, with no role in melanin and a minor role in capsule production; in C. neoformans, lesser effect of Ca2+ and not required for fluconazole tolerance in Yes, in C. gattii (molecular type-dependent) G. mellonella (wax moth) larva and A/JCr mouse inhalational models and also in C. neoformans rabbit intracisternal inoculation and BALB/c mouse i.v. inoculation models 156, 401, 402 ↵a Note the functional divergence between C. gattii and C. neoformans for all genes analyzed, with an evolutionary switch of functions of PKA1 and -2. cAMP, cyclic AMP; PKC, protein kinase C; MAPK, mitogen-activated protein kinase; PLB, phospholipase B.
- TABLE 4
Epidemiology and clinical features of major case series of Cryptococcus gattii infection c
Reference Location No. of patients Site(s) of infection Host status(es) Mortality rate (%) Induction antifungal therapy Complication(s) (no. of cases) Sequela(e) (no. or % of survivors with sequela) 218 PNG 3 (all children) Meninges IC 33 cAMB (6 wk) Abnormal mentation (2), papilledema (2), retinal hemorrhage (1) None 213 PNG 7 (1 child) Meninges IC 43 cAMB + 5FC (mean, 7 wk) Papilledema (3), blurred vision (3), deafness (1), seizures (1) Not specified 208 PNG 82 Meninges IC Not stated Not specified Visual loss in 52.6% of survivors Visual loss (52.6%) 209 PNG 88 Meninges IC 34.1 Not specified Not specified Not specified 211 PNG 49 Meninges IC 22.4 cAMB + 5FC; total dose of cAMB ranged from 890 mg to 2.4 g Papilledema (26), blurred vision (25), abnormal mentation (12), cranial nerve palsy (10), seizures (7), raised ICP (3/6) Visual loss (31%) 204 NT, Australia 18 CNS +/− lung Primarily IC Not specified for C. gattii but 9.1 overall cAMB (range, 0.85 to 5 g) Not specified Not specified 27 Australia 26 CNS (26) IC 15 cAMB + 5FC (median, 2.4 g cAMB) Papilledema (13), abnormal mentation (8), focal signs (1), seizures (10), hydrocephalus (9) Moderate-to-severe neurological sequelae (8 patients) 28 Australia 20 Meninges (17), brain (7), lungs (13) IC 0 Not specified for C. gattii Hydrocephalus (4), focal signs (5) Neurological sequelae (7 patients) 29 Australia 47 Meninges (27), brain (10), lung (30), skin (3) IC (41), IS (5) Not specified Hydrocephalus (5) Not specified 215 NT, Australia 12 CNS +/− lung (8), lung only (4) Not specified 33 cAMB + 5FC (avg, 43 days) Hydrocephalus (at least 3) Not specified 130 Australia 86 CNS +/− lung (73), lung only (10) IC (62), IS (24) 13.6 AMB + 5FC (57 patients) (6 wk), FLU (9) (4 wk), AMB + 5FC (7) (2 wk), FLU (2) (not specified) Papilledema (9), abnormal mentation (18), cerebellar deficit (10), limb weakness (6), seizures (5), cranial nerve palsy (13), raised ICP (31; 42%), hydrocephalus (22; 30%) Neurological sequelae (20; 27%) a 98 South Africa 46 Mostly meninges HIV (29), non-HIV/unknown (18) 35.6 AMB (14), FLU (32), AMB + FLU (5) 96 Botswana 29 Meninges HIV (29) 17 AMB (14 days) 131 Canada 3 Lung + CNS (1), lung only (2) IC 0 AMB (1), FLU (2) None None 198 Canada 218 Lung only (167), CNS only (17), CNS + lung (22), other (2) IC (148), IS (70) 8.7 Not specified Not specified 230 Canada 38 in case-control study b Meninges (10), lung (28) IC (not stated), IS (not stated) 132 USA (Pacific Northwest states) 96; 83 outbreak infections, 13 nonoutbreak infections Meninges (29), Brain (6), lung (31) IC (62), IS (34) 33 Not specified Papilledema (3/49), blurred vision (9/49), seizures (4/49) 248 USA (non-Pacific Northwest states) 25 CNS (19), lung (9), CNS only (12), lung only (12), blood (3), leg (1) IC (20), IS (5) 24 AMB + 5FC (17 patients), AMB (1), FLU (1), unknown (2) Papilloedema (2), blurred vision (8), seizures (1), cranial nerve palsy (5/13), hydrocephalus (4/18) Not specified 239 Vietnam 10 Meninges HIV negative 10 cAMB + 5FC (Vietnamese national guidelines) Papilledema (5), abnormal mentation (1), blurred vision (4), focal signs (5) Overall, blindness in 6 patients, deafness in 1 patient, and neurological deficits in 14 patients, but data were not stratified by infecting Cryptococcus species 206 Brazil 8 Unknown IC (7), IS (HIV infection) (1) Not stratified by cryptococcal species Not stratified by cryptococcal species 220 Brazil 11 CNS alone (9), CNS and lung (2) IC 18.2 AMB (7), AMB + 5FC (5) Hydrocephalus (6) Blindness (4 patients) 222 Brazil 21 Meninges HIV (2), non-HIV (19) 221 Brazil 25 Meninges HIV (4), non-HIV (21) 44 256 Brazil 7 (previously unreported cases only) Meninges HIV (1), IC (6) 14.3 AMB only (5), AMB + FLU (2) 251 Brazil 4 Meninges HIV (2) 50 ↵a Cranial nerve lesions, epilepsy, memory impairment, and visual field loss.
↵b The case-control study identified oral steroid use, pneumonia, and other lung conditions to be associated with infection. In population comparisons, cases were more likely to be >50 years of age, to be current smokers, to have HIV infection, or to have a history of invasive cancer.
↵c Abbreviations: AMB, amphotericin B formulation; cAMB, conventional amphotericin B deoxycholate; CNS, central nervous system; 5FC, 5-flucytosine; IC, immunocompetent; ICP, intracranial pressure; IS, immunosuppressed; PNG, Papua New Guinea.
- TABLE 5
Major clinical studies reporting antifungal susceptibility testing of Cryptococcus gattii against fluconazole c
Reference Origin(s) of isolates Total no. of isolates Source (no.) of isolates Modal MIC (mg/liter) a MIC90 (mg/liter) GM MIC (mg/liter) MIC range (mg/liter) % of isolates with MIC ≥ 32 mg/liter Description 29 Australia 18 C 4 16 NS 0.5–64 11 Primarily VGI isolates 75 Taiwan 21 C 8 16 NS 0.125–16 0 C. gattii was less susceptible to AMB and 5FC than C. neoformans; all C. gattii isolates were FLU susceptible 403 South America 11 C NS NS NS 8–16 0 High degree of susceptibility to AMB, 5FC, FLU, ITC 370 Spain 57 C (52) NS 32 9.54 1–64 NS C. gattii was less susceptible than C. neoformans to FLU but not AMB and 5FC E (5) 368 Spain 30 C (mainly) NS NS 0.7–1 0.25–2 0 Overall low-level resistance; MICs for FLU were higher for C. gattii than for C. neoformans (P = 0.007) 404 Brazil 23 C NS 25.6 15.52 4–>64 NS All strains had low MICs of AMB (0.03–0.25 mg/liter); among azoles, POS had greatest activity, followed by VOR, ITC, and FLU 366 USA 35 C (NS) NS 0.064 0.03 0.03–0.06 0 Highly susceptible to isavuconazole E (NS) 0.06 0.027 0.015–0.25 0 363 Worldwide 42 C (NS) NS 4 2.36 0.25–64 Few differences in susceptibility between C. gattii and C. neoformans E (NS) 371 USA 43 C 4 16 6.38 0.5–32 0.05 VGII molecular type strains, especially those of VGIIc, had highest FLU MICs 375 Australia, USA, Canada 45 C (NS) and E (NS); study I NS 8 3.54 1–8 0 C. gattii less susceptible than C. neoformans; strains of the VGII molecular type had significantly higher MICs for 5FC and all azoles, especially FLU 103 Extended study NS 8 4.96 1–32 NS 373 Worldwide 350 C (215) NS 8 3.573 0.25–64 NS Veterinary isolates were least susceptible to ITC, POS, VRC, and ISA; MICs varied with molecular type for FLU and 5FC 367 India 62 C (2) 1.9 1.55 1–16 0 VGI; C. gattii less susceptible than C. neoformans to FLU, ITC, and VRC but not AMB and 5FC; E was less susceptible than C and more resistant than C E (60) NS 8 8 0 405 Brazil 13 C NS NS NS 16–>64 15 VGII molecular type studied 372 Brazil 49 C (43) and E (6); VGII 16 6.08 0.25–>64 NS VGII molecular type strains less susceptible to FLU, VRC, and 5FC than VGI strains VGI 4 1.55 1–8 0 359 Global 298 C and E (NS) 8 16 5.51 0.5–32 20 Molecular type VGII strains had the highest FLU GM MICs, and molecular type VGI had the lowest (8.6 vs 1.7 mg/liter) 406 Brazil 54 C (50) NS 16 NS 1–64 NS Mainly molecular type VGII strains E (4) 369 Brazil 8 C NS 32 13.45 8–32 0 Susceptible to most drugs; no differences in susceptibility between C. neoformans and C. gattii; ECV = 32 mg/liter 374 Canada, USA 90 C (75) 4 8 4.5 2–64 NS Molecular type VGII studied, of which types IIb and IIc were less susceptible E (15) 376 b Brazil 24 NS ≤1 4 NS <0.12–32 3 3 isolates with MIC of 32 mg/liter; no molecular type stated ↵a In some instances, calculated by the authors.
↵b Measured by flow cytometry.
↵c Abbreviations: AMB, amphotericin B; C, clinical strains; E, environmental; 5FC, 5-flucytosine; FLU, fluconazole; GM, geometric mean; ITC, itraconazole; ISA, isavuconazole; POS, posaconazole; NS, not specified; VRC, voriconazole.
- Top
- Article
- SUMMARY
- INTRODUCTION
- TAXONOMY OF THE SPECIES C. GATTII
- EPIDEMIOLOGY, ORIGIN, AND EVOLUTION
- ECOLOGY
- PATHOGENESIS
- C. GATTII INFECTION IN ANIMALS
- CLINICAL EPIDEMIOLOGY OF HUMAN INFECTION
- CLINICAL MANIFESTATIONS OF HUMAN INFECTION
- CLINICAL COMPLICATIONS OF HUMAN INFECTION
- DIAGNOSTICS
- ANTIFUNGAL SUSCEPTIBILITY
- ANTIFUNGAL THERAPY AND MANAGEMENT
- CONCLUSIONS
- ACKNOWLEDGMENTS
- REFERENCES
- Author Bios
- Figures & Data
- Info & Metrics