An update on Cryptococcus among HIV-infected patients

Cryptococcus remains an important opportunistic infection in HIV patients despite considerable declines in prevalence during the highly active antiretroviral therapy era. This is particularly apparent in sub-Saharan Africa, where Cryptococcus continues to cause significant mortality and morbidity. This review discusses the microbiology, epidemiology, pathogenesis and clinical presentation of cryptococcal infections in HIV patients. Additionally, a detailed approach to the management of cryptococcosis is provided.

[Fungi as emergent etiologic agents in ventilator-associated pneumonia after cardiac surgery]

Evaluation of the fungal involvement in the etiology of ventilator-associated pneumonia (VAP) after cardiac surgery. The study had as target the patients diagnosed with VAP after cardiac surgery at the Institute of Cardiovascular Diseases in Iaşi, between April 2nd 2002 and December 31st 2009.

MATERIAL AND METHOD

Our study included only cases with fungal etiology of VAP. We examined quantitatively the tracheal aspirates with cytology quality score Q = 2+: microscopy and cultivation. The isolates with clinical significance (= 10(6)UFC/mL significantly associated to inflammatory cells) were identified by standard methods or based on the API system (bioMérieux) and tested by the breakpoints method for susceptibility to antifungal agents.

RESULTS

Among the 2167 operated patients, 35 of them were diagnosed with VAP through the clinical pulmonary infection score = 6. Fungi caused 15 of 44 VAP episodes. With a frequency of 30.19%, fungi are on 2nd place within the etiologic agents of VAP after non-fermenting Gram-negative bacilli (45.28%). The fungi involved in VAP were: Candida albicans (16.97%), Pneumocystis jirovecii (3.77%), while Candida glabrata, Candida sake, Candida krusei, Geotrichum capitatum and Cryptococcus humicola, amounted 1.89% each. The widespread use of broad spectrum antibiotics led to the emergence of fungi as a common cause of ventilator-associated pneumonia. The involvement in the VAP etiology of P. jirovecii, an un-cultivable fungus with special sensitivity to antibiotics, requires a careful microscopy of specimens.

Cryptococcocis: a rare fungal infection of the tongue

Fungal infection in the oral cavity is not uncommon. The site involved is usually species related. Cryptococcus rarely infects the oral cavity. We report an elderly patient who presented with a central lesion on the dorsum of the tongue. Biopsy revealed a fungal infection. Special stains confirmed cryptococcus. Being a rare location for cryptococcal infection, clinical suspicion should be correlated with histopathological examination. Once confirmed, the patient should be treated with an antifungal medication.

Chronic necrotizing pulmonary aspergillosis following cryptococcal infection of the lung

A 64-y-old male with steroid-induced diabetes mellitus was admitted to our hospital because of a nodular shadow found by chest radiography. Pathological examination revealed pulmonary cryptococcosis, and he was positive for serum Cryptococcus antigen. After oral treatment with fluconazole, he experienced clinical and radiographic improvement, but during ensuing observation without antifungal treatment his respiratory symptoms gradually worsened. Chest radiography showed progressive infiltration around the cavity, and Aspergillus mold was isolated by transbronchial lung biopsy from the lesion where previous cryptococcal infection was present. In addition, serum antibodies to Aspergillus antigens were demonstrated by immunodiffusion. Thus, pulmonary aspergillosis was found to complicate a case of pulmonary cryptococcal infection.

Evidence of symbiosis between the soil yeast Cryptococcus laurentii and a sclerophyllous medicinal shrub, Agathosma betulina (Berg.) Pillans

The interaction between a common soil yeast, Cryptococcus laurentii, and a slow-growing medicinal plant adapted to low-nutrient soils, Agathosma betulina (Berg.) Pillans, was studied. C. laurentii CAB 578 was isolated from the rhizosphere of wild A. betulina, and liquid chromatography-tandem mass spectrometry (LC-MS-MS) analysis revealed that the yeast was capable of producing polyamines, such as cadaverine and spermine, while growing in vitro in a chemically defined medium. Since the exogenous application of polyamines are known to impact on root growth, these findings supported the results obtained when axenic cultures of A. betulina seedlings were inoculated with C. laurentii CAB 578 and cultivated for 5 months under glasshouse conditions. The presence of the yeast increased root growth by 51%. Using soil dilution plates, it was demonstrated that yeast numbers were greater in the vicinity of the roots than in the bulk soil. In addition, fluoromicroscopy, in combination with the fluorescent probes Fungolight and Calcofluor white, revealed the presence of metabolic active yeast colonies on the rhizoplane 5 months after initiation of the experimentation. The study provided evidence for a symbiosis between C. laurentii and A. betulina.

The isolation and characterization of virulence factors of Cryptococcus spp. from saprophytic sources in the city of Ribeirão Preto, São Paulo, Brazil

Yeasts of the Cryptococcus genus are distributed in nature associated to animal and vegetal organic residues. Occasionally, species other than C. neoformans may be responsible for infectious diseases in human and animals. This study aims to determine the occurrence of Cryptococcus species in the atmosphere and bird droppings in the city of Ribeirão Preto, São Paulo, Brazil, and to evaluate three virulence factors: capsule formation, growth at 37 degrees C and melanin production. We analyzed 86 environmental samples (54 droppings and 32 air). Of the 41 strains isolated, 15 were C. neoformans var. neoformans (12 droppings and 3 air), 15 C. albidus (12 droppings and 3 air), 9 C. laurentii (7 droppings and 2 air) and 2 C. uniguttulatus (from droppings). Capsules were produced by 93.3% of C. neoformans var. neoformans, 66.7% of C. albidus, 88.9% of C. laurentii and 50% (1/2) of C. uniguttulatus. All strains of C. neoformans, 20% of C. albidus and 44.4% of C. laurentii were able to grow at 37 degrees C. The melanin production on DOPA agar was verified in C. neoformans (93.3%), C. albidus (26.7%) and C. laurentii (66.7%). We concluded that different Cryptococcus species coexist in the same ecological niche and they are able to produce virulence factors.

[The species variety and drug susceptibility of fungi isolated from blood samples of patients of the Dr. A. Jurasz university hospital in Bydgoszcz in the years 2005-2008]

The aim of the study was retrospective analysis of the species variety and the drug susceptibility to antifungal drugs of fungal strains isolated form blood samples of patients of the dr. A. Jurasz University Hospital in Bydgoszcz, in the years 2005-2008. A total of 79 strains patients was isolated from 68 during these four years. Above 96% strains belong to Candida spp., while three strains--to Cryptococcus spp. Almost 56% strains were isolated from more than one blood sample. In the first three years of analysis gradual increase of the number of cultured strains was observed, but in 2008 the decrease was noticed. The majority of strains were obtained from patients of the Anesthesiology and Intensive Care Clinic (32,9%) and the Pediatrics, Hematology and Oncology Clinic (24,1%). Every year the same species were the most frequently cultered: C. albicans, C. parapsilosis i C. glabrata. C albicans was found as the dominant species each year. Almost 32% of strains were isolated from blood samples obtained by peripheral insertion of a needle and by catheter as well. C. parapsilosis was the most frequently isolated species from those cases (48,0%). Among non-C. albicans species there were higher percentages of strains resistant to flucytosine, amphotericin B and fluconazole observed.

Cerebral infection caused by Cryptococcus gattii: a case report and antifungal susceptibility testing

We report a clinical case of cerebral infection caused by Cryptococcus gattii in a 10 year-old boy. Clinical and laboratory exams did not demonstrate any apparent immunosuppressed state (HIV antibody and the tuberculin skin tests, both negative, were performed; blood cells count and immunoglobulin levels were within normality). Treatment was begun with amphotericin B-deoxycholate but renal toxicity signs led to its substitution by fluconazole. The infection proceeded even after treatment with fluconazole. In vitro determination of minimum inhibitory concentration values were high for itraconazole (= or > 2 microg/ml), fluconazole and 5-flucytosine (= or > 64 microg/ml) and low for amphotericin B (1.0 microg/ml). Renal toxicity signs, induced by amphotericin B, progression of infection after fluconazole, and likely in vivo resistance to this triazole made this case difficult to treat. In vitro drug interaction tests confirmed probable synergism between amphotericin B and 5-flucytosine (frational inhibitory concentration - FIC = 0.375). In contrast, a probable additive effect was observed for amphotericin B and fluconazole (FIC = 0.75). Initial treatment of persistent high intracranial pressure was insufficient and neurological surgery was necessary. Antifungal susceptibility tests and Cryptococcus species identification were important in selecting appropriate antifungal therapy.

[Investigation of the presence of Cryptococcus spp. in eucalyptus trees by using sedimentation and swabbing methods]

Yeasts of the genus Cryptococcus are life-threatening microorganisms that cause cryptococcosis in both immunocompromised and immunocompetent humans and animals worldwide. In the nature, Cryptococcus species exist in eucalyptus trees and other species of trees as well as in the soil contaminated with pigeon droppings. The aim of this study was to investigate the presence of Cryptococcus spp. in the samples collected from eucalyptus trees by classic sedimentation and swabbing methods. Regarding these microorganisms, stem hollows, blossom and leaf samples from 61 trees (more than 95% were Eucalyptus camaldulensis) found in and around Adana province (located at Mediterranean region of Turkey) have been examined in June 2006 and June 2007 periods. The samples were then evaluated in terms of the growth of mucoid, dampish and brownish colonies after inoculation onto three media (Guizotia abyssinica birdseed agar with 0.1%, 0.01% and without diphenyl) and incubation in aerobic conditions at 28 degrees C for three weeks. However, no Cryptococcus spp. has been isolated from any of the samples. It was suggested that other species of trees and environmental samples should be examined for the existence of yeast fungi, so that more extensive epidemiological data could be obtained.

In vitro activities of antifungal drugs against yeasts isolated from blood cultures and moulds isolated from various clinically significant sites in Singapore

INTRODUCTION

Fungaemia carries with it high mortality rates and appropriate as well as timely antifungal therapy has been shown to be life saving.

MATERIALS AND METHODS

We studied the invitro activities of antifungal agents using the Etest method, against 100 Candida isolates from blood cultures, 10 Cryptococcus isolates from blood or cerebrospinal fluid and 50 mould isolates from various clinically significant sites of patients in Singapore General Hospital, from June 2004 to December 2006.

RESULTS

Overall, the yeasts appeared to have low minimum inhibitory concentrations (MICs) for all the 5 antifungal drugs tested except for fluconazole. The overall high MIC90 values of the moulds against the azoles were largely attributed to the non-Aspergillus moulds. Posaconazole, itraconazole, voriconazole and caspofungin appear effective against local strains of Aspergillus species, although there are no interpretive breakpoints.

CONCLUSIONS

The results show that the local fungal strains studied appear to be susceptible to the usual antifungal drugs recommended in the literature.

Treatment of cryptococcal meningitis in Peruvian AIDS patients using amphotericin B and fluconazole

OBJECTIVES

To describe the mycologic and clinical outcomes and factors associated with failure in Peruvian patients with AIDS-associated cryptococcal meningitis (CM) treated with amphotericin B deoxycholate (Amph B) followed by fluconazole.

METHODS

Patients were treated with intravenous Amph B 0.7 mg/kg/day for 2 or 3 weeks followed by oral fluconazole 400mg/day for 7 or 8 weeks. Clinical and laboratory evaluations including cerebrospinal fluid (CSF) studies were performed at baseline and at weeks 2 and 10.

RESULTS

The CSF cultures were negative in 25% and 68% of 47 patients at weeks 2 and 10, respectively. In the univariate analysis, baseline low body mass index (BMI), hyponatremia, low serum albumin, positive blood culture and CSF antigen titers >or=1024 were associated with a positive CSF culture at week 2. Baseline positive urine culture, positive blood culture, any positive extraneural culture and CSF opening pressure at week 2 >or=300 mm H2O were associated with a positive CSF culture at week 10. In the multivariate analysis no association was found.

CONCLUSIONS

Therapy with Amph B and fluconazole, combined with aggressive management of elevated intracranial pressure (ICP), results in low CSF sterilization rates at week 2 and acceptable CSF sterilization rates at week 10 when compared with other series.

[Epidemiological, clinical and prognostic aspects of cryptococcal meningitis in hospital area of Bamako, Mali]

The cryptococcosis is a major mycosis of forecast holds during the AIDS. The objective of this study was to determine the frequency of this affection during the AIDS with the service of the infectious diseases of the teaching hospital of the Point G. On the whole 55 patients reached of AIDS were included in this study. They presented all of the evocative signs of meningitis attack. The analysis of the cerebral spinal fluid (CSF) allowed us to detect among this population 17 cases of cryptococcal meningitis means a frequency of 30.9%. The average age was 34 years with the extreme ones going from 18 to 60 years old. The clinical signs were as follows: disorder of the conscious in 4/17 cases (23.6%), fever in 2/17 cases (11.8%), signs of meningitis in 11/17 cases (64.7%). The CSF was clear as water of rock with a lymphocyte at 100% to all the patients. The examination with the Indian ink noted yeasts in capsular identified like the Cryptococcus ones. The treatment was based on amphotericin B intravenous. Lethality rate was 58.8% in 10/17 cas. The crytococcus constitutes a frequent etiology of the meningo-encephalitis demonstrations during the AIDS in this service. We recommend the search for cryptococcus in front of any sign of meningitis occurring during AIDS in Mali.

Communicating the risks of a new, emerging pathogen: the case of Cryptococcus gattii

The news media are an important channel for communicating public health messages, providing important information about geographic extent, symptoms, and precautionary measures. This function may be particularly important in the case of new and emerging infectious diseases, which are unfamiliar to both the public and health professionals. We conducted a content analysis of the coverage in six Canadian newspapers of two emerging infectious pathogens in British Columbia (BC), West Nile virus and Cryptococcus gattii (C. gattii), between 2001 and 2006. C. gattii was first identified in the Canadian Pacific Northwest in 1999, having previously been restricted to tropical and subtropical areas. By summer 2006, C. gattii had killed at least eight people and was responsible for over 150 hospitalizations in the province of BC, as well as significant morbidity and mortality among companion animals. West Nile virus reached Canada in 2001 and has since caused significant morbidity and mortality. It has not, to date, reached BC. Despite the much higher incidence of disease and death caused by C. gattii in BC, West Nile virus received five times more news coverage in the British Columbian and national newspapers examined. Surprisingly, the local newspaper closest to the center of the British Columbia C. gattii outbreak had a much lower proportion of coverage of the disease than other papers in the province. The article discusses possible explanations for these findings, and the implications for public health communication.

Cryptococcus gattii fungemia: report of a case with lung and brain lesions mimicking radiological features of malignancy

A 64-year-old apparently immunocompetent white man developed lung and brain lesions of disseminated cryptococcosis. The radiologic features mimicked those of lung cancer metastatic to the central nervous system. C. gattii was recovered from cultures of bronchoalveolar lavage fluid, brain biopsy, and blood. The same fungus was recovered from pulmonary and brain specimens at autopsy. Serum and cerebrospinal fluid cryptococcal antigen tests were diagnostic in our case and should be included in the diagnostic evaluation of unexplained pulmonary and cerebral lesions. A literature search showed few reports of fungemia by this species of Cryptococcus, contrasting to C. neoformans.

First case of feline systemicCryptococcus albidusinfection

This paper, as best as the authors can determine, is the first to describe a documented case of systemic infection caused by Cryptococcus albidus in a cat. The patient had a history of paralysis of the hind legs and had been treated with prednisone for 1 month. Microscopic examination of a fine needle biopsy specimen from a right popliteal lymph node showed granulomatous inflammation with many encapsulated yeast cells. Moreover, microscopic examination of Indian ink preparations of the cerebrospinal fluid revealed encapsulated ovoid yeast cells. Thus this case was diagnosed to be cryptococcosis. However, the cat died after treatment for three days with voriconazole. Isolates recovered from samples of the cerebrospinal fluid, liver and spleen were identified as C. albidus by molecular analysis, as well as through morphologic and biochemical studies. Therefore, this case indicates that C. albidus should be considered as a potential feline pathogen.

Bilateral multifocal choroiditis and optic neuropathy in a patient with AIDS: a diagnostic dilemma

A rare case of bilateral multifocal choroiditis and optic neuropathy as the result of disseminated cryptococcal infection in a person with AIDS is described. A 30-year-old HIV-positive man presented with fever, headache, vomiting, and altered sensorium Ophthalmological examination revealed bilateral multifocal choroiditis and optic neuropathy. Laboratory examination and imaging suggested a presumptive diagnosis of disseminated Cryptococcus neoformans infection. Therapeutic response confirmed the diagnosis.

Inulinase-producing marine yeasts: evaluation of their diversity and inulin hydrolysis by their crude enzymes

Total 427 yeast strains from seawater, sediments, mud of salterns, guts of the marine fish, and marine algae were obtained. After inulinase activity of the yeast cultures was estimated, we found that four strains (OUC1, G7a, OUC2, and G7a1) of the marine yeasts grown in the medium with inulin could secrete a large amount of inulinase into the medium. The results of routine identification and molecular methods show that they belong to Pichia guilliermondii OUC1, Cryptococcus aureus G7a, Yarrowia lipolytica OUC2, and Debaryomyces hansenii G7a1, respectively. The optimal pHs of inulinase activity produced by them were 6.0, 5.0, 5.0, and 5.0, respectively, while the optimal temperatures of inulinase activity produced by them were 60 degrees , 50 degrees , 60 degrees , and 50 degrees C, respectively. A large amount of monosaccharides and a trace amount of oligosaccharides were detected after the hydrolysis by the crude inulinase produced by P. guilliermondii OUC1, indicating that the crude inulinase had a high exoinulinase activity while a large amount of monosaccharides and oligosaccharides were detected after inulin hydrolysis by the crude inulinase produced both by C. aureus G7a and D. hansenii G7a1. However, no monosaccharides and disaccharides were detected after inulin hydrolysis by the crude inulinase produced by Y. lipolytica OUC2, suggesting that the crude inulinase had no exoinulinase activity.

Cryptococcus arboriformis Sp. Nov., a novel anamorphic basidiomycetous yeast species isolated from a patient's urine

A basidiomycetous yeast strain isolated from the urine of a 73-year-old Japanese patient with chronic renal failure was revealed to be a novel species by sequencing the D1/D2 26S rDNA and ITS regions of the rRNA gene. The name Cryptococcus arboriformis sp. nov. is proposed for the isolate, with IFM 54862(T) (=CBS 1044(T) =JCM 14201(T)) as the type strain. A phylogenetic analysis positioned Cryptococcus arboriformis in the Trichosporonales lineage and showed that it is closely related to C. haglerorum.

Subcutaneous cryptococcosis due to Cryptococcus diffluens in a patient with sporotrichoid lesions case report, features of the case isolate and in vitro antifungal susceptibilities

Environmental fungi, in particular primary pathogens and Cryptococcus spp. can be responsible for skin lesions mimicking sporotrichosis. In this paper, we report a case of subcutaneous cryptococcosis in an apparently healthy, young male patient due to a non-C. neoformans Cryptococcus species, C. diffluens. The isolate showed in vitro phenotypic switching that may affect virulence and host inflammatory and immune responses, and in vitro resistance to amphotericin B and 5-flucytosin. This species shares several phenotypic traits with C. neoformans, and, therefore, decisive diagnosis should be based on biopsy and culturing results followed by molecular identification.

Ecological niche of Cryptococcus neoformans var. grubii and Cryptococcus gattii in decaying wood of trunk hollows of living trees in Jabalpur City of Central India

Cryptococcus neoformans var. grubii and C. gattii were repeatedly isolated from decaying wood of trunk hollows in living trees growing in Jabalpur City in Central India. The isolation of C. gattii has been reported from decayed wood inside trunk hollow of Tamarindus indica (15.6%), Mangifera indica (2.2%), Pithecolobium dulce (12.5%), Syzygium cumini (14%), and one from bark of S. cumini. C. n. var. grubii was isolated from decaying wood debris of T. indica (4.4%), M. indica (13.3%), Terminalia arjuna (25%), S. cumini (2%), Cassia fistula (4.5%), and two from bark of S. cumini. The two species [corrected] never co-occurred in the same hollow. C. gattii [corrected] isolates belonged to serotype B. [corrected] The data strongly supported the colonization of the pathogen in decaying wood hollow of all six-tree species. Evidence of this was found by repeated isolation up to 820 days. P. dulce is being reported for the first time as natural habitat of C. gattii and T. arjuna and C. fistula as natural habitat for C. n. var. grubii. M. indica is being reported for the second time as the natural habitat of both species [corrected] (C. n. var. grubii and C. gattii). The population density of these pathogens from decaying wood debris of various tree species ranged between 0.5 x 10(3) cells/g and 6 x 10(5) cells/g. The seasonal variation has been seen in isolation of these pathogens. [corrected] Our result further reinforce the recently emerging evidence that the natural habitat of C. n. var. grubii and C. gattii is more generalized.