Generalized systemic cryptococcosis in a dog after immunosuppressive corticotherapy

Um cão da raça Boxer, macho, com 2 anos e 11 meses de idade foi encaminhado ao hospital veterinário com histórico de distúrbio gastroentérico de dois meses de duração, apatia, hiporexia, emagrecimento progressivo e deficiência visual. Ataxia e vocalização foram observadas posteriormente. O animal estava sendo tratado em outra clínica veterinária com antibióticos e doses imunossupressoras de corticóides, direcionados ao controle de provável enterite alimentar. A morte ocorreu após cinco dias. As observações macro e microscópica revelaram tratar-se de criptococose sistêmica, atingindo trato digestório, olhos, SNC, rins, pâncreas e linfonodos. O presente relato enfatiza a infecção fúngica criptocócica quanto aos seus aspectos grastrointestinais iniciais a serem considerados no diagnóstico clínico, ressaltando a imunossupressão induzida pela corticoterapia.

Primary cutaneous cryptococcosis in Brazil: report of 11 cases in immunocompetent and immunosuppressed patients

Background Primary cutaneous cryptococcosis is an uncommon infectious disease caused by Cryptococcus neoformans or Cryptococcus gattii affecting immunosuppressed as well as immunocompetent patients. It is often misdiagnosed as it may mimic other cutaneous diseases. Materials and methods We report a series of cases diagnosed from 2005 to 2010 in two general hospitals. The diagnosis in all patients was made on the basis of histopathology and culture. Phenoloxidase and canavanine-glycine-bromothymol blue tests were used in order to identify the Cryptococcus species. Systematic investigation ruled out the systemic involvement in every case. Results Eleven patients, 81.8% male, were diagnosed during this study. The immunosuppression status was identified in 54.5% of patients, and all of them were under corticosteroid therapy due to a variable set of diseases. All patients presented with circumscribed lesions on their upper limbs. Most lesions showed an infiltrative or tumoral aspect with up to 40 cm diameter. Fluconazole, up to 400 mg/daily, was the main therapeutic regimen and proved to be efficient. Conclusions Primary cutaneous cryptococcosis has been diagnosed in both immunosuppressed and immunocompetent patients. Its peculiar clinical aspect could facilitate early diagnosis. Culture and biochemical tests should be performed in order to define the species involved.

Cryptococcosis outbreak in psittacine birds in Brazil

An outbreak of cryptococcosis occurred in a breeding aviary in São Paulo, Brazil. Seven psittacine birds (of species Charmosyna papou, Lorius lory, Trichoglossus goldiei, Psittacula krameri and Psittacus erithacus) died of disseminated cryptococcosis. Incoordination, progressive paralysis and difficulty in flying were seen in five birds, whereas superficial lesions coincident with respiratory alterations were seen in two birds. Encapsulated yeasts suggestive of Cryptococcus sp. were seen in faecal smears stained with India ink in two cases. Histological examination of the birds showed cryptococcal cells in various tissues, including the beak, choana, sinus, lungs, air sacs, heart, liver, spleen, kidneys, intestines and central nervous system. High titres of cryptococcal antigen were observed in the serum of an affected bird. In this case, titres increased during treatment and the bird eventually died. Yeasts were isolated from the nasal mass, faeces and liver of one bird. Cryptococcus neoformans var. gattii serovar B was identified based on biochemical, physiological and serological tests. These strains were resistant (minimum inhibitory concentration 64 μ g/ml) to fluconazole. This is the first report of C. neoformans var. gattii occurring in psittacine birds in Brazil. © 2004 ISHAM.

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. © 2013 Springer-Verlag Berlin Heidelberg.

Primary endemic Cryptococcosis gattii by molecular type VGII in the state of Pará, Brazil

In order to study the infectious agents causing human disseminated cryptococcosis in the state of Pará, North Brazil, 56 isolates of Cryptococcusspp. (54 isolated from cerebral spinal fluid and two from blood cultures) from 43 cases diagnosed between 2003-2007 were analysed. The species were determined through morphological and physiological tests and genotypes were determined by URA5-RFLP and PCR-fingerprinting (wild-type phage M13). The following species and genotypes were identified: Cryptococcus neoformans VNI (28/56, 50%), Cryptococcus gattii VGII (25/56, 44.64%) and C. gattii VGI (3/56, 5.26%). The genotype VNI occurred in 12 out of 14 HIV-positive adults, whereas the genotype VGII occurred in 11 out of 21 HIV-negative adults (p < 0.02, OR = 6.6 IC95% 0.98-56.0). All patients less than 12 years old were HIV negative and six cases were caused by the VGII genotype, one by the VGI and one by VNI. Therefore, endemic primary mycosis in HIV-negative individuals, including an unexpectedly high number of children, caused by the VGII genotype deserves further study and suggests the need for surveillance on cryptococcal infection in the state of Pará, Eastern Amazon.

Voriconazole, Combined with Amphotericin B, in the Treatment for Pulmonary Cryptococcosis Caused by C. neoformans (Serotype A) in Mice with Severe Combined Immunodeficiency (SCID)

Cryptococcosis is a subacute or chronic systemic mycosis with a cosmopolitan nature, caused by yeast of the genus Cryptococcus neoformans. The model of systemic cryptococcosis in mice with severe combined immunodeficiency (SCID) is useful for immunological and therapeutic study of the disease in immunodeficient hosts. Amphotericin B, fluconazole and flucytosine are the drugs most commonly used to treat cryptococcosis. Voriconazole is a triazole with high bioavailability, large distribution volume, and excellent penetration of the central nervous system. The objective of this study was to evaluate treatment with amphotericin B (AMB), voriconazole (VRC), and AMB, used in combination with VRC, of experimental pulmonary cryptococcosis in a murine model (SCID). The animals were inoculated intravenously (iv) with a solution containing 3.0 x 10(5) viable cells of C. neoformans ATCC 90112, (serotype A). Treatments were performed with amphotericin B (1.5 mg/kg/day), voriconazole (40.0 mg/kg/day) and AMB (1.5 mg/kg/day) combined with VRC (40.0 mg/kg/day); began 1 day after the initial infection; were daily; and lasted 15 days. Evaluations were performed using analysis of the survival curve and isolation of yeast in the lung tissue. There was a significant increase in survival in groups treated with AMB combined with VRC, compared with the untreated group and groups receiving other treatments (P < 0.05). In the group treated only with VRC and AMB combined with VRC, there was a significant reduction (P < 0.05) in the isolation of C. neoformans in lung tissue. Amphotericin B combined with voriconazole may be an effective alternative to increasing survival and may reduce yeast in the lung tissue of mice with pulmonary cryptococcosis and SCID.

Desenvolvimento de um instrumento de avaliação da vulnerabilidade de pacientes imunodeprimidos a infecções zoonóticas a partir de animais de estimação.

Os animais de estimação podem ser fonte de infecções, principalmente para seres humanos imunocomprometidos, em especial, pacientes portadores do vírus HIV. Considerando que o contato com animais pode prover benefícios emocionais, profissionais da área da saúde, em particular médicos e médicos veterinários, devem estar conscientes do papel potencial destes animais na transmissão de doenças de forma a preconizar medidas profiláticas para que esta transmissão não ocorra. As circunstâncias que favorecem a transmissão de doenças a partir dos animais de estimação ainda não são totalmente conhecidas, principalmente na realidade brasileira. Faltam estudos com o objetivo de investigar o risco de doenças de origem zoonótica decorrentes do contato com estes animais, hoje também chamados de animais pet. Ademais, ressente-se da falta de um instrumento devidamente elaborado e validado com a finalidade de captar as informações necessárias para a realização de estudos deste tipo ou mesmo para servir como ferramenta de rastreio de situações de vulnerabilidade de pacientes imunodeprimidos com vistas ao aconselhamento sobre medidas de prevenção. Desta maneira, o objetivo deste estudo é elaborar um instrumento para averiguar a vulnerabilidade de pacientes imunodeprimidos a infecções zoonóticas a partir de animais de estimação. Inicialmente, foram mapeados os animais de estimação mais encontrados no ambiente doméstico e as principais infecções que podem ser transmitidas a partir deles. Selecionaram-se, então, os possíveis mecanismos de transmissão a serem abordados. Dentre as espécies de animais de estimação elencadas, os cães, gatos, aves, répteis e os pequenos roedores foram os selecionados para a confecção deste instrumento. As infecções selecionadas foram: Salmonelose; Criptosporidíase; Giardíase; Dermatofitoses, Esporotricose, Bartonelose; Ancilostomíase; Toxocaríase; Psitacose; Toxoplasmose; Escabiose; Campilobacteriose; Criptococose e Histoplasmose. Considerando as diferentes formas de transmissão de cada infecção foram identificados os possíveis atos e comportamentos no contato com animais de estimação, bem como características destes animais, que poderiam aumentar a probabilidade de transmissão. O instrumento desenvolvido foi composto de uma primeira parte abarcando os critérios de elegibilidade, e de outra envolvendo o escopo principal do instrumento. Como as características de contato e as infecções variam de acordo com a espécie de animal, o instrumento abordou cada um dos cinco grupos de animais separadamente. O instrumento aqui proposto concerne à etapa inicial de um processo de desenvolvimento formal para utilização em futuras pesquisas sobre o papel dos animais de estimação na transmissão de infecções para pacientes imunodeprimidos. Estudos que explorem a confiabilidade e validade do instrumento proposto, assim como sua aceitabilidade, são necessários antes que seu uso seja recomendado.

Clinical practice guidelines for the management of cryptococcal disease: 2010 update by the infectious diseases society of america.

Cryptococcosis is a global invasive mycosis associated with significant morbidity and mortality. These guidelines for its management have been built on the previous Infectious Diseases Society of America guidelines from 2000 and include new sections. There is a discussion of the management of cryptococcal meningoencephalitis in 3 risk groups: (1) human immunodeficiency virus (HIV)-infected individuals, (2) organ transplant recipients, and (3) non-HIV-infected and nontransplant hosts. There are specific recommendations for other unique risk populations, such as children, pregnant women, persons in resource-limited environments, and those with Cryptococcus gattii infection. Recommendations for management also include other sites of infection, including strategies for pulmonary cryptococcosis. Emphasis has been placed on potential complications in management of cryptococcal infection, including increased intracranial pressure, immune reconstitution inflammatory syndrome (IRIS), drug resistance, and cryptococcomas. Three key management principles have been articulated: (1) induction therapy for meningoencephalitis using fungicidal regimens, such as a polyene and flucytosine, followed by suppressive regimens using fluconazole; (2) importance of early recognition and treatment of increased intracranial pressure and/or IRIS; and (3) the use of lipid formulations of amphotericin B regimens in patients with renal impairment. Cryptococcosis remains a challenging management issue, with little new drug development or recent definitive studies. However, if the diagnosis is made early, if clinicians adhere to the basic principles of these guidelines, and if the underlying disease is controlled, then cryptococcosis can be managed successfully in the vast majority of patients.

Invasive fungal infections among organ transplant recipients: results of the Transplant-Associated Infection Surveillance Network (TRANSNET).

BACKGROUND: Invasive fungal infections (IFIs) are a major cause of morbidity and mortality among organ transplant recipients. Multicenter prospective surveillance data to determine disease burden and secular trends are lacking. METHODS: The Transplant-Associated Infection Surveillance Network (TRANSNET) is a consortium of 23 US transplant centers, including 15 that contributed to the organ transplant recipient dataset. We prospectively identified IFIs among organ transplant recipients from March, 2001 through March, 2006 at these sites. To explore trends, we calculated the 12-month cumulative incidence among 9 sequential cohorts. RESULTS: During the surveillance period, 1208 IFIs were identified among 1063 organ transplant recipients. The most common IFIs were invasive candidiasis (53%), invasive aspergillosis (19%), cryptococcosis (8%), non-Aspergillus molds (8%), endemic fungi (5%), and zygomycosis (2%). Median time to onset of candidiasis, aspergillosis, and cryptococcosis was 103, 184, and 575 days, respectively. Among a cohort of 16,808 patients who underwent transplantation between March 2001 and September 2005 and were followed through March 2006, a total of 729 IFIs were reported among 633 persons. One-year cumulative incidences of the first IFI were 11.6%, 8.6%, 4.7%, 4.0%, 3.4%, and 1.3% for small bowel, lung, liver, heart, pancreas, and kidney transplant recipients, respectively. One-year incidence was highest for invasive candidiasis (1.95%) and aspergillosis (0.65%). Trend analysis showed a slight increase in cumulative incidence from 2002 to 2005. CONCLUSIONS: We detected a slight increase in IFIs during the surveillance period. These data provide important insights into the timing and incidence of IFIs among organ transplant recipients, which can help to focus effective prevention and treatment strategies.

Unrecognized pretransplant and donor‐derived cryptococcal disease in organ transplant recipients.

BACKGROUND: Cryptococcosis occurring ≤30 days after transplantation is an unusual event, and its characteristics are not known. METHODS: Patients included 175 solid-organ transplant (SOT) recipients with cryptococcosis in a multicenter cohort. Very early-onset and late-onset cryptococcosis were defined as disease occurring ≤30 days or >30 days after transplantation, respectively. RESULTS: Very early-onset disease developed in 9 (5%) of the 175 patients at a mean of 5.7 days after transplantation. Overall, 55.6% (5 of 9) of the patients with very early-onset disease versus 25.9% (43 of 166) of the patients with late-onset disease were liver transplant recipients (P = .05). Very early cases were more likely to present with disease at unusual locations, including transplanted allograft and surgical fossa/site infections (55.6% vs 7.2%; P < .001). Two very early cases with onset on day 1 after transplantation (in a liver transplant recipient with Cryptococcus isolated from the lung and a heart transplant recipient with fungemia) likely were the result of undetected pretransplant disease. An additional 5 cases involving the allograft or surgical sites were likely the result of donor‐acquired infection. CONCLUSIONS: A subset of SOT recipients with cryptococcosis present very early after transplantation with disease that appears to occur preferentially in liver transplant recipients and involves unusual sites, such as the transplanted organ or the surgical site. These patients may have unrecognized pretransplant or donor-derived cryptococcosis.

Interaction of Cryptococcus neoformans Rim101 and protein kinase A regulates capsule.

Cryptococcus neoformans is a prevalent human fungal pathogen that must survive within various tissues in order to establish a human infection. We have identified the C. neoformans Rim101 transcription factor, a highly conserved pH-response regulator in many fungal species. The rim101 multiply sign in circle mutant strain displays growth defects similar to other fungal species in the presence of alkaline pH, increased salt concentrations, and iron limitation. However, the rim101 multiply sign in circle strain is also characterized by a striking defect in capsule, an important virulence-associated phenotype. This capsular defect is likely due to alterations in polysaccharide attachment to the cell surface, not in polysaccharide biosynthesis. In contrast to many other C. neoformans capsule-defective strains, the rim101 multiply sign in circle mutant is hypervirulent in animal models of cryptococcosis. Whereas Rim101 activation in other fungal species occurs through the conserved Rim pathway, we demonstrate that C. neoformans Rim101 is also activated by the cAMP/PKA pathway. We report here that C. neoformans uses PKA and the Rim pathway to regulate the localization, activation, and processing of the Rim101 transcription factor. We also demonstrate specific host-relevant activating conditions for Rim101 cleavage, showing that C. neoformans has co-opted conserved signaling pathways to respond to the specific niche within the infected host. These results establish a novel mechanism for Rim101 activation and the integration of two conserved signaling cascades in response to host environmental conditions.

Emergence and pathogenicity of highly virulent Cryptococcus gattii genotypes in the northwest United States.

Cryptococcus gattii causes life-threatening disease in otherwise healthy hosts and to a lesser extent in immunocompromised hosts. The highest incidence for this disease is on Vancouver Island, Canada, where an outbreak is expanding into neighboring regions including mainland British Columbia and the United States. This outbreak is caused predominantly by C. gattii molecular type VGII, specifically VGIIa/major. In addition, a novel genotype, VGIIc, has emerged in Oregon and is now a major source of illness in the region. Through molecular epidemiology and population analysis of MLST and VNTR markers, we show that the VGIIc group is clonal and hypothesize it arose recently. The VGIIa/IIc outbreak lineages are sexually fertile and studies support ongoing recombination in the global VGII population. This illustrates two hallmarks of emerging outbreaks: high clonality and the emergence of novel genotypes via recombination. In macrophage and murine infections, the novel VGIIc genotype and VGIIa/major isolates from the United States are highly virulent compared to similar non-outbreak VGIIa/major-related isolates. Combined MLST-VNTR analysis distinguishes clonal expansion of the VGIIa/major outbreak genotype from related but distinguishable less-virulent genotypes isolated from other geographic regions. Our evidence documents emerging hypervirulent genotypes in the United States that may expand further and provides insight into the possible molecular and geographic origins of the outbreak.

Cryptococcal cell morphology affects host cell interactions and pathogenicity.

Cryptococcus neoformans is a common life-threatening human fungal pathogen. The size of cryptococcal cells is typically 5 to 10 microm. Cell enlargement was observed in vivo, producing cells up to 100 microm. These morphological changes in cell size affected pathogenicity via reducing phagocytosis by host mononuclear cells, increasing resistance to oxidative and nitrosative stress, and correlated with reduced penetration of the central nervous system. Cell enlargement was stimulated by coinfection with strains of opposite mating type, and ste3aDelta pheromone receptor mutant strains had reduced cell enlargement. Finally, analysis of DNA content in this novel cell type revealed that these enlarged cells were polyploid, uninucleate, and produced daughter cells in vivo. These results describe a novel mechanism by which C. neoformans evades host phagocytosis to allow survival of a subset of the population at early stages of infection. Thus, morphological changes play unique and specialized roles during infection.