Non-neoformans cryptococcal infections: a systematic review

Cryptococcus laurentii fungemia in a low birth weight preterm neonate: India

In the last few years, Cryptococcus laurentii infections have increased, particularly in immunocompromised patients. Here we report the first case of C. laurentii fungemia in low birth weight preterm infant from India. A preterm neonate was admitted for feeding intolerance and respiratory distress. Blood culture ascertained the causative organism as C. laurentii. The isolated strain was found susceptible to amphotericin B and the patient recovered following the administration of amphotericin B (5mg/kg body weight) for 8days.

Cryptococcal disease in the solid organ transplant setting: review of clinical aspects with a discussion of asymptomatic cryptococcal antigenemia

PURPOSE OF REVIEW

Cryptococcal infections are an important cause of morbidity and mortality in solid organ transplant patients. Here, we review the microbiology, epidemiology, clinical course, treatment, and outcomes of Cryptococcus in solid organ transplant recipients.

RECENT FINDINGS

We identify the unique findings in solid organ transplant patients when compared to other immunocompromised patients such as those with HIV. We also describe our experience and outcomes with regard to solid organ transplant patients who do not have positive fungal cultures, but cryptococcal antigen positivity and concern for cryptococcal disease.

SUMMARY

Our review will highlight the importance of these new diagnostic techniques in those with Cryptococcus and solid organ transplant, which will be the subject of new research.

Environmental distribution of Cryptococcus species and some other yeast-like fungi in India

A study of environmental distribution revealed the occurrence of Cryptococcus neoformans and C. gattii in 9% and 3%, respectively, of 611 samples investigated. C. neoformans showed the highest isolation frequency from tree trunk hollows in Delhi (31%), whereas C. gattii occurred in 12% of the samples in Delhi and 5% in Rajasthan. In addition, Cryptococcus laurentii (=Papiliotrema laurentii), C. rajasthanensis (=Papiliotrema rajasthanensis), C. podzolicus (=Saitozyma podzolica) and C. flavescens (=Papiliotrema flavescens) occurred in 0.5% each. The recovery of C. flavescens and C. podzolicus was new findings for India. One more noteworthy finding was isolation of a new yeast, recently classified as Saitozyma cassiae sp. Novo. The previous strain of this yeast came from tree bark debris in South India. Our isolates came from decayed wood inside a trunk hollow of an Acacia tree in, Bharatpur Bird Sanctuary, Rajasthan. The isolations of novel strains of Cutaneotrichosporon moniliiforme from decayed wood of a Pinus tree was another significant finding. Phenotypically, they differed from T. moniliforme by being encapsulated cells, had melanin-like pigment production and were unable to assimilate d-manitol and d-melezitose. AFLP analysis showed a distinctive banding profile vis-a-vis the reference strains of T. moniliiforme and Cryptotrichosporon anacardii.

Mode of action and synergistic effect of valinomycin and cereulide with amphotericin B against Candida albicans and Cryptococcus albidus

Both valinomycin and cereulide are cyclic depsipeptides and are known K⁺ ion-selective ionophores. Valinomycin and cereulide feature low minimum inhibitory concentration (MIC) values against Candida albicans and Cryptococcus albidus. This study aims at investigating the mode of action and verifying the efficacy of valinomycin or cereulide alone and in combination with amphotericin B (AmB) in vitro against both microorganisms. Based on the results from membrane permeability and fluidity assays for detection of plasma membrane permeabilization and membrane dynamics, the present study demonstrated that valinomycin and cereulide exhibit antifungal activity against C. albicans and C. albidus by interrupting membrane-associated function. The mode of action of both valinomycin and cereulide are similar with that of AmB. Time-kill kinetics assay showed that valinomycin and cereulide exhibit fungistatic activity, whereas AmB features fungicidal activity. Additionally, the combination of compounds between each cyclic peptide and AmB reached maximal fungicidal activity more rapidly than AmB alone. This result corresponded with findings of scanning electron microscopy, fractional inhibitory concentration index and minimum fungicidal concentration (MFC)/MIC ratio, indicating that combinations of the drugs show synergistic effects for inhibiting the growth of these fungal strains. Sorbitol and ergosterol assays showed that both cyclic peptides affected cell wall and membrane components due to increases in MIC value, as observed in medium with sorbitol and ergosterol. Valinomycin and cereulide may promote permeability of fungal cell wall and cell membrane when used in combination with AmB.

The hidden pathogenic potential of environmental fungi

Invasive fungal infections are a growing threat to immunocompromised patients, highlighting the importance of monitoring fungal pathogens. Global warming (including climatic oscillations) may select for environmental species that have acquired thermotolerance, a key step toward pathogenesis to humans. Also, important virulence factors have developed in environmental fungi, because they are essential for yeast survival in the environment. Thus, fungi traditionally regarded as nonpathogenic to humans have virulence factors similar to those of their pathogenic relatives. Here, we highlight the emergence of saprophytic environmental fungi - including species of Cryptococcus, Aspergillus, Penicillium, Candida and Scedosporium - as new human pathogens. Emerging pathogens are, in some cases, resistant to the available antifungals, potentiating the threat of novel fungal diseases.

Antifungal and Anti-Biofilm Activity of Essential Oil Active Components against Cryptococcus neoformans and Cryptococcus laurentii

Cryptococcosis is an emerging and recalcitrant systemic infection occurring in immunocompromised patients. This invasive fungal infection is difficult to treat due to the ability of Cryptococcus neoformans and Cryptococcus laurentii to form biofilms resistant to standard antifungal treatment. The toxicity concern of these drugs has stimulated the search for natural therapeutic alternatives. Essential oil and their active components (EO-ACs) have shown to possess the variety of biological and pharmacological properties. In the present investigation the effect of six (EO-ACs) sourced from Oregano oil (Carvacrol), Cinnamon oil (Cinnamaldehyde), Lemongrass oil (Citral), Clove oil (Eugenol), Peppermint oil (Menthol) and Thyme oil (thymol) against three infectious forms; planktonic cells, biofilm formation and preformed biofilm of C. neoformans and C. laurentii were evaluated as compared to standard drugs. Data showed that antibiofilm activity of the tested EO-ACs were in the order: thymol>carvacrol>citral>eugenol=cinnamaldehyde>menthol respectively. The three most potent EO-ACs, thymol, carvacrol, and citral showed excellent antibiofilm activity at a much lower concentration against C. laurentii in comparison to C. neoformans indicating the resistant nature of the latter. Effect of the potent EO-ACs on the biofilm morphology was visualized using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), which revealed the absence of extracellular polymeric matrix (EPM), reduction in cellular density and alteration in the surface morphology of biofilm cells. Further, to realize the efficacy of the EO-ACs in terms of human safety, cytotoxicity assays and co-culture model were evaluated. Thymol and carvacrol as compared to citral were the most efficient in terms of human safety in keratinocyte- Cryptococcus sp. co-culture infection model suggesting that these two can be further exploited as cost-effective and non-toxic anti-cryptococcal drugs.

Perspectives on non-neoformans cryptococcal opportunistic infections

Non-neoformans Cryptococcus species, including C. laurentii and C. albidus, have historically been classified as exclusively saprophytic. However, recent studies have increasingly implicated these organisms as the causative agent of opportunistic infections in humans. Herein, the case is presented of C. laurentii meningitis in a critically ill patient receiving corticosteroids. C. laurentii has been implicated in an additional 18 cases of opportunistic infection, predominantly of the skin, bloodstream, and central nervous system. The most clinically significant risk factors for non-neoformans cryptococcal infections include: impaired cell-mediated immunity, recent corticosteroid use, and invasive catheter placement. This article provides a comprehensive review of the clinical relevance, pathogenesis, risk factors, and treatment of non-neoformans Cryptococcus species.

Atypical Morphology and Disparate Speciation in a Case of Feline Cryptococcosis

A 6-year-old, spayed female cat was presented with acute respiratory signs and pleural effusion. Computed tomography scan revealed a large, lobulated mass effect in the ventral right hemithorax with concurrent sternal lymphadenopathy. A cytologic sample of the mass contained pyogranulomatous inflammation, necrotic material, and abundant yeast structures that lacked a distinct capsule and demonstrated rare pseudohyphal forms. Fungal culture and biochemical testing identified the yeast as Cryptococcus albidus, with susceptibility to all antifungal agents tested. However, subsequent 18S PCR identified 99% homology with a strain of Cryptococcus neoformans and only 92% homology with C. albidus. The patient responded well to fluconazole therapy unlike the only known previous report of C. albidus in a cat. The unusual cytologic morphology in this case underscores the need for ancillary testing apart from microscopy for fungal identification. Though C. albidus should be considered as a potential feline pathogen, confirmation with PCR is recommended when such rare non-neoformans species are encountered.

Yeasts

Yeasts are unicellular organisms that reproduce mostly by budding and less often by fission. Most medically important yeasts originate from Ascomycota or Basidiomycota. Here, we review taxonomy, epidemiology, disease spectrum, antifungal drug susceptibility patterns of medically important yeast, laboratory diagnosis, and diagnostic strategies.

Cryptococcosis in HIV-negative Patients with Renal Dialysis: A Retrospective Analysis of Pooled Cases

Cryptococcosis is a lethal fungal infection mainly caused by Cryptococcus neoformans/C. gattii species. Currently, our understanding of cryptococcosis episodes in HIV-negative patients during renal dialysis remains scarce and fragmented. Here, we performed an analysis of pooled cases to systemically summarize the epidemiology and clinical characteristics of cryptococcosis among HIV-negative patients with renal dialysis. Using pooled data from our hospital and studies identified in four medical databases, 18 cases were identified and analyzed. The median duration time of renal dialysis for peritoneal renal dialysis and hemodialysis cases was 8 months and 36 months, respectively. Several non-neoformans/gattii species were identified among the renal dialysis recipients with cryptococcosis, particularly Cryptococcus laurentii and Cryptococcus albidus, which share similar clinical manifestations as those caused by C. neoformans and C. gattii. Our analyses suggest that physicians should consider the possibility of the occurrence of cryptococcosis among renal dialysis recipients even when cryptococcal antigen test result is negative. The timely removal of the catheter is crucial for peritoneal dialysis patients with cryptococcosis. In addition, there is a need for optimized antifungal treatment strategy in renal dialysis recipients with cryptococcal infections.

First case of superficial infection due to Naganishia albida (formerly Cryptococcus albidus) in Iran: A review of the literature

Background and Purpose:

Naganishia albida (formerly Cryptococcus albidus) is a non-neoformans cryptococcal species rarely isolated as a human pathogen.

Case report:

Herein, we present the case of a 26-year-old Iranian man with a superficial cutaneous lesion in the axilla. The initial treatment for pityriasis versicolor by clotrimazole was unsuccessful. We performed skin sampling based on the standard protocol and conducted further investigations by the conventional laboratory tests and molecular analysis of the skin samples. All the mentioned analyses revealed N.albida as the causative agent of infection. The minimum inhibitory concentration (MIC) analysis was carried out for the isolated agent, and the patient was treated using 100 mg daily of oral itraconazole.

Conclusion:

N. albida can be the causative agent of some superficial infections. This is the first report on the successful detection and treatment of a superficial skin infection due to N. albida by oral itraconazole.

Diversity, in-vitro virulence traits and antifungal susceptibility pattern of gastrointestinal yeast flora of healthy poultry, Gallus gallus domesticus

Background

Poultry farming and consumption of poultry (Gallus gallus domesticus) meat and eggs are common gastronomical practices worldwide. Till now, a detailed understanding about the gut colonisation of Gallus gallus domesticus by yeasts and their virulence properties and drug resistance patterns in available literature remain sparse. This study was undertaken to explore this prevalent issue.

Results

A total of 103 specimens of fresh droppings of broiler chickens (commercial G domesticus) and domesticated chickens (domesticated G domesticus) were collected from the breeding sites. The isolates comprised of 29 (33%) Debaryozyma hansenii (Candida famata), 12 (13.6%) Sporothrix catenata (C. ciferrii), 10 (11.4%) C. albicans, 8 (9.1%) Diutnia catenulata (C. catenulate), 6 (6.8%) C. tropicalis, 3 (3.4%) Candida acidothermophilum (C. krusei), 2 (2.3%) C. pintolopesii, 1 (1.1%) C. parapsilosis, 9 (10.2%) Trichosporon spp. (T. moniliiforme, T. asahii), 4 (4.5%) Geotrichum candidum, 3 (3.4%) Cryptococcus macerans and 1 (1%) Cystobasidium minuta (Rhodotorula minuta). Virulence factors, measured among different yeast species, showed wide variability. Biofilm cells exhibited higher Minimum Inhibitory Concentration (MIC) values (μg/ml) than planktonic cells against all antifungal compounds tested: (fluconazole, 8–512 vs 0.031–16; amphotericin B, 0.5–64 vs 0.031–16; voriconazole 0.062–16 vs 0.062–8; caspofungin, 0.062–4 vs 0.031–1).

Conclusions

The present work extends the current understanding of in vitro virulence factors and antifungal susceptibility pattern of gastrointestinal yeast flora of G domesticus. More studies with advanced techniques are needed to quantify the risk of spread of these potential pathogens to environment and human.

The environmental yeast Cryptococcus liquefaciens produces capsular and secreted polysaccharides with similar pathogenic properties to those of C. neoformans

Invasive fungal infections, including cryptococcosis, are a growing threat to immunocompromised patients. Although Cryptococcus neoformans and Cryptococcus gattii are the main agents of human cryptococcosis, opportunistic infections by environmental species, such as C. liquefaciens, have been observed recently. The main Cryptococcus virulence factor is the production and secretion of polysaccharides (PS). Previously, we showed that both species produce PS of similar composition. Here, we examined the ultrastructure and biological activity of capsular and secreted PS from C. liquefaciens, and yeast pathogenicity to an invertebrate host, in comparison with C. neoformans. Ultrastructural analysis by high-resolution microscopy showed that both species produce large and complex capsules. PS from both species had indistinguishable effects on phagocytosis levels, NO production and the secretion of a variety of immune mediators. Challenge with C. liquefaciens or C. neoformans led to complete lethality of G. mellonella larvae. Treatment with C. liquefaciens PS could not protect mice against infection with C. neoformans. We conclude that polysaccharides of the environmental yeast C. liquefaciens have strikingly similar ultrastructural and biological properties to those of C. neoformans, highlighting the importance of monitoring the emergence of new fungal pathogens for which thermotolerance may be an important transitional step towards pathogenesis in humans.

Cryptococcus laurentii diarrhea post hematopoietic stem cell transplant

We report the recent isolation of Cryptococcus laurentii from the feces of a patient with Hodgkin's lymphoma who underwent autologous hematopoietic stem cell transplant (HSCT). The organism was identified using microscopic morphology, cultural characteristics, and biochemical tests including sugar assimilation. Minimum inhibitory concentration of various antifungals was determined by microbroth dilution method. The recovery of pure culture of C. laurentii from stool culture, and the patient's response to treatment with voriconazole support its potential etiological role. To the best of our knowledge, we report the first case of diarrhea caused by C. laurentii in an HSCT recipient.

Plants promote mating and dispersal of the human pathogenic fungus Cryptococcus

Infections due to Cryptococcus are a leading cause of fungal infections worldwide and are acquired as a result of environmental exposure to desiccated yeast or spores. The ability of Cryptococcus to grow, mate, and produce infectious propagules in association with plants is important for the maintenance of the genetic diversity and virulence factors important for infection of animals and humans. In the Western United States and Canada, Cryptococcus has been associated with conifers and tree species other than Eucalyptus; however, to date Cryptococcus has only been studied on live Arabidopsis thaliana, Eucalyptus sp., and Terminalia catappa (almond) seedlings. Previous research has demonstrated the ability of Cryptococcus to colonize live plants, leaves, and vasculature. We investigated the ability of Cryptococcus to grow on live seedlings of the angiosperms, A. thaliana, Eucalyptus camaldulensis, Colophospermum mopane, and the gymnosperms, Pseudotsuga menziesii (Douglas fir), and Tsuga heterophylla (Western hemlock). We observed a broad-range ability of Cryptococcus to colonize both traditional infection models as well as newly tested conifer species. Furthermore, C. neoformans, C. deneoformans, C. gattii (VGI), C. deuterogattii (VGII) and C. bacillisporus (VGIII) were able to colonize live plant leaves and needles but also undergo filamentation and mating on agar seeded with plant materials or in saprobic association with dead plant materials. The ability of Cryptococcus to grow and undergo filamentation and reproduction in saprobic association with both angiosperms and gymnosperms highlights an important role of plant debris in the sexual cycle and exposure to infectious propagules. This study highlights the broad importance of plants (and plant debris) as the ecological niche and reservoirs of infectious propagules of Cryptococcus in the environment.

The first report of onychomycosis caused by Cryptococcus friedmannii (Naganishia friedmannii) a basidiomycetous yeast

Yeasts are common etiologic agents of onychomycosis. This study reported a case of onychomycosis due to Cryptococcus friedmannii (Naganishia friedmannii). This yeast was isolated of the right great toenail of 57-year-old man. Microscopic examination of nail scrapings showed budding cells with thin capsule. Sequence analyzes of the internal transcribed spacer regions was closely related to Cryptococcus friedmannii. The results of susceptibility testing showed the Cryptococcus friedmannii to be sensitive to fluconazole, itraconazole and amphotericin B.

A Case of Disseminated Infection with Skin Manifestation due to Non-neoformans and Non-gattii Cryptococcus in a Patient with Refractory Acute Myeloid Leukemia

Cryptococcus spp. other than Cryptococcus neoformans or Cryptococcus gattii were previously considered saprophytes and thought to be non-pathogenic to humans. However, opportunistic infections associated with non-neoformans and non-gattii species, such as Cryptococcus laurentii and Cryptococcus albidus, have increased over the past four decades. We experienced a case of cryptococcosis caused by non-neoformans and non-gattii spp. in a 47-year-old female with refractory acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation. The patient underwent salvage chemotherapy with fluconazole prophylaxis and subsequently developed neutropenic fever with multiple erythematous umbilicated papules. A skin biopsy revealed fungal hyphae and repetitive blood cultures showed yeast microorganisms that were identified later as C. laurentii by Vitek-II^®. Skin lesions and fever began to improve with conventional amphotericin B therapy. The treatment regimen was continued for 21 days until the disseminated cryptococcosis was completely controlled.

Predominance of Cryptococcus neoformans var. grubii multilocus sequence type 5 and emergence of isolates with non-wild-type minimum inhibitory concentrations to fluconazole: a multi-centre study in China

There are few data on the molecular epidemiology of cryptococcosis in China. Here we investigated the species distribution, molecular types and antifungal susceptibilities of 312 Cryptococcus neoformans species complex isolates from ten hospitals over 5 years. Isolates were identified by internal transcribed spacer (ITS) sequencing and by two matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems. Multilocus sequence typing (MLST) was used to verify species/variety and to designate molecular types. Susceptibility to six antifungal drugs was determined by the Sensititre YeastOne™ method. Cryptococcus neoformans was the predominant species (305/312 isolates (97.8%), all were ITS type 1, serotype A), of which 89.2% (272/305) were C. neoformans var. grubii MLST sequence type (ST) 5 and 6.2% (19/305) were ST31. Other C. neoformans var. grubii STs were rare but included six novel STs. Only two strains were C. neoformans var. neoformans (both serotype AD). Cryptococcus gattii was uncommon (n = 7, four ITS types) and comprised five MLST STs including one novel ST. For C. neoformans var. grubii, the proportion of isolates with non-wild-type MICs to fluconazole significantly rose in the fourth study year (from 0% (0/56 isolates) in the first year to 23.9% (17/71) in the fourth year), including five isolates with fluconazole MICs of ≥32 mg/L. The study has provided useful data on the species epidemiology and their genetic diversity and antifungal susceptibility. The proportional increase in isolates with non-wild-type MICs to fluconazole is noted.

Misidentification of a Rare Species, Cryptococcus laurentii, by Commonly Used Commercial Biochemical Methods and Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Systems: Challenges for Clinical Mycology Laboratories

Forty-two putative Cryptococcus laurentii isolates identified by the Vitek 2 system were collected in China. The gold standard, internal transcribed spacer (ITS) sequencing, confirmed that only two isolates were genuine C. laurentii. Bruker Biotyper matrix-assisted laser desorption ionization-time of flight mass spectrometry was able to identify the C. laurentii isolates with an expanded custom database.

Cryptococcus laurentii fungaemia in a cervical cancer patient

Infections caused by emerging Cryptococcus non-neoformans species are being reported with increasingly frequency. Here, we present a case of fungaemia by Cryptococcus laurentii in a woman receiving aggressive immunosuppressive therapy for cervical neoplasia. Three venous blood samples were aseptically collected on consecutive days and C. laurentii was isolated and identified through phenotypic and molecular methods. After central venous catheter removal and appropriate antifungal therapy, the patient showed significant improvement and blood culture became negative. Thus, patients following immunosuppressive therapies and using invasive medical devices are at risk of C. laurentii blood infections.

Fatal Case of Polymicrobial Meningitis Caused by Cryptococcus liquefaciens and Mycobacterium tuberculosis Complex in a Human Immunodeficiency Virus-Infected Patient

We describe a fatal case of polymicrobial meningitis in a human immunodeficiency virus-infected patient from Guatemala caused by Cryptococcus liquefaciens and Mycobacterium tuberculosis complex. Central nervous system infections caused concurrently by these species are extremely rare. This is also the first report of disseminated disease caused by C. liquefaciens.

Cryptococcus laurentii Diarrhea in a Neoplastic Patient

We present a rare case of diarrhea and neutropenia caused by Cryptococcus laurentii (C. laurentii) infection in old patient with metastatic rectal cancer who underwent FOLFOX plus Cetuximab chemotherapy. C. laurentii is an extremely rare human pathogen. To the best of our knowledge, here, we report the first case of diarrhea and neutropenia caused by C. laurentii in a 74-year-old man with metastatic rectal cancer and hepatic metastases who underwent FOLFOX plus Cetuximab chemotherapy.

A rare case report of central line-associated bloodstream infection caused by Cryptococcus arboriformis

Cryptococcus arboriformis (C. arboriformis) is a novel Cryptococcus species belonging to the genus Trichosporonales. This novel species was identified definitively in 2007 using D1/D2 26S ribosomal DNA gene sequencing. In this article, we present a rare case of central line-associated bloodstream infection caused by C. arboriformis with successful treatment of this infection.

Successful treatment of Cryptococcus laurentii peritonitis in a patient on peritoneal dialysis

A 32-year-old man on peritoneal dialysis (PD) was hospitalized for seven days due to fever. A diagnosis of yeast-like fungal peritonitis was made by Gram staining. The patient was started on intravenous micafungin and oral fluconazole therapy following removal of the PD catheter. A fungal pathogen was isolated from the peritoneal fluid and identified as Cryptococcus species. Based on antifungal susceptibility testing, the treatment was changed to voriconazole and continued for 3 months. A genetic analysis identified the isolate as Cryptococcus laurentii (C. laurentii). This patient was diagnosed with C. laurentii PD-related peritonitis and was successfully treated with voriconazole and removal of the PD catheter.

The first reported case of central venous catheter-related fungemia caused by Cryptococcus liquefaciens

We describe a case of central venous catheter-related fungemia caused by Cryptococcus liquefaciens, a non-neoformans and non-gattii Cryptococcus, in a non-HIV patient. A 71-year-old man with diffuse large B-cell lymphoma receiving antineoplastic chemotherapy was febrile approximately 30 weeks after central venous port insertion, and C. liquefaciens was isolated from all three performed blood cultures as well as a central venous catheter tip culture. In vitro antifungal susceptibility tests showed that this yeast isolate was susceptible to low concentrations of amphotericin B, fluconazole, itraconazole and voriconazole yet was resistant to 5-fluorocytosine (MIC: >64 μg/ml), unlike Cryptococcus neoformans. Treatment of the patient with oral and intravenous voriconazole was effective and consistent with the susceptibility tests. Although non-neoformans and non-gattii Cryptococcus spp. are considered non-pathogenic environmental yeast, they may rarely be the causative agents of serious infections in humans, as in the present case.

Molecular identity and prevalence of Cryptococcus spp. nasal carriage in asymptomatic feral cats in Italy

Cryptococcosis is a life-threatening fungal disease that infects humans and animals worldwide. Inhalation of fungal particles from an environmental source can cause primary infection of the respiratory system. As animals can be considered a sentinel for human diseases, the aim of this study was to determine the prevalence and molecular identity of Cryptococcus spp. in the nasal cavity of feral cats. Cats from 162 urban and rural feral cat colonies were sampled over 3 years. Of 766 cats from which nasal swabs were obtained, Cryptococcus spp. were recovered from 95 (12.6%), including 37 C. magnus (4.8%), 16 C. albidus (2.0%), 15 C. carnescens (1.9%), 12 C. neoformans (1.6%), as well as C. oeirensis (n = 3), C. victoriae (n = 3), C. albidosimilis (n = 2), Filobasidium globisporum (n = 2), C. adeliensis (n = 1), C. flavescens (n = 1), C. dimnae (n = 1), C. saitoi (n = 1), and C. wieringae (n = 1) with prevalence <1%. Thirteen Cryptococcus species were identified by polymerase chain reaction and sequencing of internal transcribed spacer amplicons. Statistical analysis did not identify any predisposing factors that contributed to nasal colonization (eg, sex, age, season, or habitat). Results suggest that asymptomatic feral cats may carry C. neoformans and other Cryptococcus species in their sinonasal cavity. Genotyping of the specific cryptococcal isolates provides a better understanding of the epidemiology of these yeasts.

MALDI-TOF MS for the identification of veterinary non-C. neoformans-C. gattii Cryptococcus spp. isolates from Italy

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) offers an effective alternative to phenotypic and molecular methods for the rapid identification of microorganisms. Our aim in this study was to create an in-house library for a set of strains of nine uncommonly reported human and animal cryptococcal species, including Cryptococcus adeliensis, C. albidosimilis, C. albidus, C. aureus, C. carnescens, C. laurentii, C. magnus, C. victoriae and C. uniguttulatus, and to use this library to make timely and correct identifications using MALDI-TOF MS for use in routine laboratory diagnostics. Protein extracts obtained via the formic acid extraction method of 62 veterinary non-C. neoformans-C. gattii cryptococcal isolates were studied. The obtained mass spectra correctly grouped all 62 studied isolates according to species identification previously obtained by internal transcribe spacer sequence analysis. The in-house database was than exported and successfully uploaded to the Microflex LT (Maldi Biotyper; Bruker Daltonics) instrument at a different diagnostic laboratory in Italy. Scores >2.7 obtained from isolates reanalyzed in the latter laboratory supported the high reproducibility of the method. The possibility of creating and transferring an in-house library adds to the usefulness MALDI-TOF MS an important tool for the rapid and inexpensive identification of pathogenic and saprophytic fungi as required for differential diagnosis of human and animal mycoses.

Case Report of Cryptococcus Albidus Peritonitis in a Peritoneal Dialysis Patient and a Review of the Literature

Cryptococcus albidus is a saprophytic yeast linked to just 26 reports of human infection in the world literature. Here, we report the first case of C. albidus peritonitis, in a patient with end-stage renal disease and hepatitis C-associated cirrhosis who is on peritoneal dialysis. The patient was treated successfully with a week-long course of amphotericin B. Non-neoformans cryptococcal infections present a clinical challenge, because they are difficult to diagnose and lack established guidelines for treatment. We present a review of the literature on C. albidus infections and their treatment.

A rare case of Cryptococcus luteolus-related tenosynovitis

A 68-year-old male with type II diabetes mellitus presented with a nodule over the metacarpophalangeal joint of his right second finger after being spurred on the hand by a domestic turkey 2 weeks prior to onset of clinical symptoms. He was diagnosed with cryptococcal tenosynovitis caused by Cryptococcus luteolus identified by DNA sequencing. Complete clinical resolution was achieved with synovectomy and debridement followed by 1 year of fluconazole 800 mg daily.

Cryptococcus spp. isolation from excreta of pigeons (Columba livia) in and around Monterrey, Mexico

The presence of Cryptococcus spp. has been reported in Mexico’s capital city; however, to our knowledge there are no reports of its presence in the state of Nuevo León located in northeast Mexico. This is presumed to be because the hot and dry climate in this region does not favor cryptococcal proliferation. This study confirmed the presence of C. neoformans and C. albidus in 20% (10/50) of randomly selected fecal samples of pigeons (Columba livia) in the Monterrey metropolitan area. The presence of this yeast in the state of Nuevo León is proof of its adaptation to the typically hot climate of the area and is consistent with recent reviews of cryptococcosis cases in several local hospitals. The two species were identified and characterized through microbiological tests and molecular identification by DNA extraction and PCR amplification of highly conserved 18S ribosomal DNA using ITS1 and ITS2 as target regions. The PCR products were sequenced and compared with those reported in GenBank.

Cryptococcus albidus encephalitis in newly diagnosed HIV-patient and literature review

We present the first case of encephalitis caused by Cryptococcus albidus duo to AIDS. In addition, we give an overview of the literature of extra-dermal infection cases caused by C. albidus. In the 21 cases, HIV and organ transplantation were important risk factors especially in recent 20 years. Fungal culture or India ink preparations are the best way to demonstrate C. albidus in both serum and CSF.

Potentially pathogenic yeasts from soil of children's recreational areas in the city of Łódź (Poland)

OBJECTIVES

Yeasts may become potential human and animal pathogens, particularly for individuals with a depressed immune system. Their presence in the environment, especially in soil, may favour their spread into human ontocenoses.

MATERIALS AND METHODS

Eighty-four soil samples obtained from 21 children's recreational sites in Łódź in autumn 2010 and spring 2011 were evaluated. The yeasts were isolated by classical microbiological methods and identified on the basis of morphological and biochemical features.

RESULTS

The fungi were found in 73.8% and in 69.0% of the examined samples collected in autumn and spring, respectively. Among 97 isolates of yeasts, the species potentially pathogenic to humans and animals were Candida colliculosa, C. guilliermondii, C. humicola, C. inconspicua, C. lambica, C. lusitaniae, C. pelliculosa, C. tropicalis, Cryptococcus albidus, C. laurentii, C. neoformans, C. terreus, Kloeckera japonica, Geotrichum candidum, G. penicillatum, Rhodotorula mucilaginosa, R. glutinis, Saccharomyces cerevisiae, Sporobolomyces salmonicolor and Trichosporon cutaneum. The most frequently isolated fungi included the genus Cryptococcus (38 isolates) and two species: Rhodotorula glutinis (15), Trichosporon cutaneum (14). C. neoformans, an etiological factor of cryptococcal meningitis, was present in the sandpits of 3 kindergartens. The Candida species were identified from park playgrounds and school sports fields mainly in autumn 2010 (14 isolates), in spring 2011 - only 1 isolate. The concentration of fungal species in particular samples varied considerably, but in the majority of samples, fungi were present at concentration of up to 1×10(2) CFU/1 g of soil.

CONCLUSIONS

Yeasts were present in the soil of parks, schools and kindergarten recreational areas; the fact may pose a health risk to humans, especially to children, and this type of biological pollution should be regarded as a potential public health concern.

Cryptococcosis: epidemiology, fungal resistance, and new alternatives for treatment

Cryptococcosis is an important systemic mycosis and the third most prevalent disease in human immunodeficiency virus (HIV)-positive individuals. The incidence of cryptococcosis is high among the 25 million people with HIV/acquired immunodeficiency syndrome (AIDS), with recent estimates indicating that there are one million cases of cryptococcal meningitis globally per year in AIDS patients. In Cryptococcus neoformans, resistance to azoles may be associated with alterations in the target enzyme encoded by the gene ERG11, lanosterol 14α-demethylase. These alterations are obtained through mutations, or by overexpressing the gene encoding. In addition, C. gattii and C. neoformans present a heteroresistance phenotype, which may be related to increased virulence. Other species beyond C. neoformans and C. gattii, such as C. laurentii, have been diagnosed mainly in patients with immunosuppression. Infections of C. albidus have been isolated in cats and marine mammals. Recent evidence suggests that the majority of infections produced by this pathogen are associated with biofilm growth, which is also related with increased resistance to antifungal agents. Therefore, there is a great need to search for alternative antifungal agents for these fungi. The search for new molecules is currently occurring from nanoparticle drugs of plant peptide origin. This article presents a brief review of the literature regarding the epidemiology of cryptococcosis, as well as fungal resistance and new alternatives for treatment.

New Insights into HIV/AIDS-Associated Cryptococcosis

Cryptococcal meningitis is a life-threatening opportunistic fungal infection in both HIV-infected and HIV-uninfected patients. According to the most recent taxonomy, the responsible fungus is classified into a complex that contains two species (Cryptococcus neoformans and C. gattii), with eight major molecular types. HIV infection is recognized worldwide as the main underlying disease responsible for the development of cryptococcal meningitis (accounting for 80-90% of cases). In several areas of sub-Saharan Africa with the highest HIV prevalence despite the recent expansion of antiretroviral (ARV) therapy programme, cryptococcal meningitis is the leading cause of community-acquired meningitis with a high mortality burden. Although cryptococcal meningitis should be considered a neglected disease, a large body of knowledge has been developed by several studies performed in recent years. This paper will focus especially on new clinical aspects such as immune reconstitution inflammatory syndrome, advances on management, and strategies for the prevention of clinical disease.

Assessment of plant lectin antifungal potential against yeasts of major importance in medical mycology

The search for new compounds with antifungal activity is accelerating due to rising yeast and fungal resistance to commonly prescribed drugs. Among the molecules being investigated, plant lectins can be highlighted. The present work shows the potential of six plant lectins which were tested in vitro against yeasts of medical importance, Candida albicans, Candida tropicalis, Candida parapsilosis, Cryptococcus gattii, Cryptococcus neoformans, Malassezia pachydermatis, Rhodotorula sp. and Trichosporon sp. Broth microdilution susceptibility testing was performed in accordance with standard protocols to evaluate antifungal activity. Minimum inhibitory concentration (MIC) was determined at 80% yeast growth inhibition, whereas the minimum fungicidal concentration (MFC) was evaluated after making the subcultures of each dilution. Only C. parapsilosis growth was inhibited by the lectins tested. Abelmoschus esculentus lectin showed the highest MIC (0.97 μg ml(-1)). Lectins from Canavalia brasiliensis, Mucuna pruriens and Clitoria fairchildiana presented the highest MFC at (3.90 μg ml(-1)). These results encourage further studies with wider yeast strain selections, and open new perspectives for the development of pharmacological molecules.

Sequence diversity of the intergenic spacer region of the rRNA gene of Cryptococcus albidus isolated from the skin of patients with atopic dermatitis and healthy individuals

The yeast species Cryptococcus albidus var. albidus was found to more often colonize the skin surface of patients with atopic dermatitis (77.0%, 47/61) than that of  healthy subjects (37.5%, 15/40). The intergenic spacer 1 region of the rRNA gene of this species consists of four sequence types: I, II, III and IV. Types I and II were predominant among healthy subjects and atopic dermatitis patients, respectively.