Biomedical subjects

B Wanke

Publications and source records attributed to B Wanke.

At least 19 recordsLinked to original sources

PubMed2004

Molecular epidemiology of Cryptococcus neoformans isolates from AIDS patients of the Brazilian city, Rio de Janeiro.

A high biodiversity of Cryptococcus neoformans isolates is known to exist in some Brazilian urban areas, raising the possibility that patients may encounter multiple inoculum sources in their daily life. C. neoformans isolates from two groups of AIDS patients with cryptococcosis from Rio de Janeiro were studied by polymerase chain reaction (PCR) fingerprinting and randomly amplified polymorphic DNA (RAPD) analysis. The first group contained 60 serial isolates obtained from 19 patients over periods ranging from 18 to 461 days; the intent was to determine whether the original strain persisted or whether reinfection with a new strain occurred. The second group was made up of 22 isolates from 11 patients, and consisted of a pair of isolates collected from blood and cerebrospinal fluid from each patient either before or shortly after treatment was initiated. The aim was to determine if the patient was infected by different strains simultaneously. All isolates were subtyped by PCR fingerprinting, using minisatellite (M13), and microsatellite [(GACA)4 and (GTG)5] specific primers, and RAPD analysis employing the combined primers 5SOR and CN1. The majority of isolates were C. neoformans var. grubii, specifically, molecular types VNI or VNII, but numerous distinguishable subtypes were found. Only three isolates were C. n. var. gattii (molecular types VGI or VGII). Except in two cases, all isolates obtained from the same patient showed identical PCR profiles independent of time of isolation or body site. Almost all patients, however, carried unique genotypes not found in any other patient. Our results confirm that persistent cryptococcal infection is caused by relapse rather than reinfection, but they also show that in exceptional cases, patients may be infected with more than one C. neoformans strain.

AIDS-Related Opportunistic Infections↗

PubMed2004

Disseminated dermatophytosis caused by Microsporum gypseum in an AIDS patient: response to terbinafine and amorolfine.

A 51-year-old white male, native of Rio de Janeiro, Brazil, with advanced AIDS and in chronic use of imidazoles for oral candidosis, presented erythematous, desquamative, pruriginous plaques of 1 month evolution on the trunk, inguinal/crural region, and lower limbs. The diagnosis of dermatophytosis was based on the isolation of Microsporum gypseum from scales scraped from the skin lesions. The lesions regressed after 30 days treatment with itraconazole, 100 mg day(-1). After interruption of this antifungal, the mycosis recurred 2 months later, along with a toe onychomycosis also caused by M. gypseum. Attempted reintroduction of itraconazole at higher dose was unsuccessful. Patient responded well to treatment with terbinafine 250 mg day(-1) for 45 days. However, the medication had to be interrupted as a result of the emergence of a disseminated erythematous/papulous rash. Topical treatment with amorolfine cream was then performed, with a good clinical and mycological response.

AIDS-Related Opportunistic Infections↗

PubMed2003

Pathology of sporotrichosis in 10 cats in Rio de Janeiro.

Ten cats with sporotrichosis were examined clinically and pathologically. They were in very poor general condition, and had widespread ulcerated cutaneous lesions and respiratory signs. Gross internal abnormalities were found only in the lungs and lymph nodes. Histologically, an inflammatory infiltrate and yeast-like structures were observed in the skin, lungs, liver and lymph nodes. The spleen was congested and contained fungal elements. No microscopical changes were observed in the pancreas, kidneys and heart. Sporothix schenckii was isolated from all the skin samples and nasal swabs obtained in vivo, and from all the samples of lung, liver, spleen, lymph nodes, heart and kidney taken postmortem.

Animals↗

PubMed2003

Genetic characterization of environmental isolates of the Cryptococcus neoformans species complex from Brazil.

The genetic affiliation of a large number of isolates of the Cryptococcus neoformans species complex from environmental sources in Brazil has been investigated using amplified fragment length polymorphism (AFLP). The strains of C. neoformans isolated from a single tree, as well as from neighbouring trees, showed high similarity values (> 95%) of their AFLP patterns, thus suggesting considerable genetic homogeneity. The majority of isolates of C. neoformans belonged to AFLP genotype 1, and had serotype A and mating type alpha (= C. neoformans var. grubii). Three isolates belonged to AFLP genotype 2, with serotype D and mating type alpha (= C. neoformans var. neoformans). One isolate, obtained from a building in Rio de Janeiro inhabited by pigeons, belonged to the AD hybrid AFLP genotype 3. All isolates from trees of C. neoformans var. gattii (= C. gattii) belonged to AFLP genotype 6, and their banding patterns showed relatively low genetic homogeneity with a similarity value of about 76%. Isolates of this genotype occupy an environmental niche in the Americas, and they may cause disease in non-AIDS and AIDS patients as well.

Air Microbiology↗

PubMed2003

Haematogenous spread of Sporothrix schenckii in cats with naturally acquired sporotrichosis.

The recovery of Sporothrix schenckii from blood samples is rare, and the diagnosis of systemic sporotrichosis is usually made at necropsy. In this report, S schenckii was isolated from two or more internal organs of nine necropsied cats with naturally acquired sporotrichosis. Haematogenous spread was demonstrated in vivo by the isolation of S schenckii from the peripheral blood of 17 (n = 49, 34.4 per cent) cats. Feline leukaemia virus (FeLV) was not detected, and co-infection with feline immunodeficiency virus (FIV), observed in nine cases (n = 43, 20.9 per cent), apparently did not affect the isolation of S schenckii from peripheral blood or from the internal organs.

Animals↗

PubMed2001

Biogeographic range expansion into South America by Coccidioides immitis mirrors New World patterns of human migration.

Long-distance population dispersal leaves its characteristic signature in genomes, namely, reduced diversity and increased linkage between genetic markers. This signature enables historical patterns of range expansion to be traced. Herein, we use microsatellite loci from the human pathogen Coccidioides immitis to show that genetic diversity in this fungus is geographically partitioned throughout North America. In contrast, analyses of South American C. immitis show that this population is genetically depauperate and was founded from a single North American population centered in Texas. Variances of allele distributions show that South American C. immitis have undergone rapid population growth, consistent with an epidemic increase in postcolonization population size. Herein, we estimate the introduction into South America to have occurred within the last 9,000-140,000 years. This range increase parallels that of Homo sapiens. Because of known associations between Amerindians and this fungus, we suggest that the colonization of South America by C. immitis represents a relatively recent and rapid codispersal of a host and its pathogen.

Base Sequence↗

PubMed2001

Coccidioides immitis isolated from armadillos (Dasypus novemcinctus) in the state of Piauí, northeast Brazil.

Natural infection of armadillos with Coccidioides immitis was studied in the state of Piauí, northeast of Brazil, endemic for coccidioidomycosis. In 1998, 26 nine-banded armadillos (Dasypus novemcinctus) were captured in 4 different counties. The animals were sacrificed under deep anesthesia with ether. At necropsy fragments of spleen, liver, lungs and heart were homogenized and seeded onto Sabouraud dextrose agar with and without cycloheximide (BBL, USA). Part of each organ was also processed for histological examination. Suspected colonies of filamentous fungi observed after the second week of incubation at room temperature, exhibiting barrel-shaped arthroconidia alternating with empty spaces, were inoculated intraperitoneally into mice. Three armadillos proved to be infected with C. immitis. Mice inoculated with suspected colonies obtained from homogenized spleen of three and liver of two armadillos developed disseminated coccidioidomycosis and immature and mature spherules of C. immitis were disclosed in several organs. For the first time armadillos (D. novemcinctus) were found naturally infected with C. immitis, adding new data on the ecology and on a possible role of these ancestral mammals in the evolutionary life cycle of this fungus.

Animals↗

PubMed2001

First isolation of Cryptococcus neoformans var. gattii from a native jungle tree in the Brazilian Amazon rainforest.

Cryptococcus neoformans var. gattii was isolated for the first time from decaying wood in a hollow of a native jungle tree Guettarda acreana, in a wild area of an Amazon rainforest island, in Brazil. The presence of this variety in a virgin environment without either anthropic action or introduced vegetation is discussed with regard to the common knowledge of Cr. neoformans ecology.

Brazil↗

PubMed2001

Osteomyelitis caused by Paracoccidioides brasiliensis in a child from the metropolitan area of Rio de Janeiro.

The authors describe a case of paracoccidioidomycosis in a 7-year-old girl from the city of Rio de Janeiro who initially presented to her physician with a lesion in her calcaneous which was misdiagnosed and treated as bacterial osteomyelitis. Later, cutaneous manifestations, lymph node enlargement, and hepatosplenomegaly developed and biopsy of the skin and cervical lymph nodes showed the fungus which was also present in the sputum. It is emphasized that Paracoccidioides brasiliensis can be the cause of bone lesions in endemic areas of Latin America and that response to treatment with amphotercin B is good.

Amphotericin B↗

PubMed2001

Sporotrichosis: an emergent zoonosis in Rio de Janeiro.

During the period from 1987 to 1998, 13 cases of human sporotrichosis were recorded at the Research Center Evandro Chagas Hospital (CPqHEC) in Rio de Janeiro. Two of these patients related scratch by a sick cat. During the subsequent period from July 1998 to July 2000, 66 human, 117 cats and 7 dogs with sporotrichosis were diagnosed at the CPqHEC. Fifty-two humans (78.8%) reported contact with cats with sporotrichosis, and 31 (47%) of them reporting a history of a scratch or bite. This epidemic, unprecedented in the literature, involving cats, dogs and human beings may have started insidiously before 1998.

Adolescent↗

PubMed2000

Possible primary ecological niche of Cryptococcus neoformans.

To study hollows of living trees as natural habitats of Cryptococcus neoformans in an endemic area of cryptococcosis in the northeastern region of Brazil, samples of decaying wood were collected inside 32 hollows of living trees and plated on niger seed agar. Identification of C. neoformans was based upon morphological and physiological tests. Canavanine-glycine-bromothymol medium was used to screen the varieties and Crypto Check Iatron Kit to serotype the isolates. A total of 123 C. neoformans colonies were recovered from samples of six (18.5%) out of 32 hollow trees. C. neoformans var. neoformans and C. neoformans var. gattii were found occurring alone (pink shower tree, fig tree and pottery tree) or sharing the same hollow (pink shower tree). Long lasting positivity (19-36 months) and significant number of cfu of C. neoformans per gram of decaying wood (0.15-21.7 x 10(3) cfu g(-1)) inside hollows of pink shower tree, fig tree and pottery tree were observed, indicating colonization of these habitats by the fungus. For the first time, C. n. var. neoformans and C. n. var. gattii were found sharing the same natural biotope, thus establishing a possible link between them in their life cycle in nature and suggesting the primary natural niche for the species.

Colony Count, Microbial↗

PubMed2000

Fungal infections in the immunocompromised host.

In recent years many remarkable changes occurred in our way of life, producing opportunities for microbes. All these changes are related to the recent emergence of previously unrecognized diseases, or the resurgence of diseases that, at least in developed countries, were thought to be under control. This concept is reviewed regarding fungal infections and their agents in the immunocompromised host. The changing pattern of these infections, the portals of entry of fungi into the human host, fungal pathogenicity and the main predisposing factors are analyzed. Opportunistic fungal infections in cancer, organ transplant and acquired immunodeficiency syndrome patients are reviewed, specially candidiasis and aspergillosis.

AIDS-Related Opportunistic Infections↗

PubMed2000

Clues to the presence of pathogenic fungi in certain environments.

The presence of various pathogenic fungi in rather unsuspected hosts and environments has always attracted the attention of the scientific community. Reports on the putative role of animals in fungal infections of humans bear important consequences on public health as well as on the understanding of fungal ecology. Fungi are ubiquitous in nature and their great capacity for adaptation allows them to survive and indeed, to thrive, in plants, trees and other natural substrata. Nonetheless, we are just beginning to learn the significance that these diverse fungal habitats have on the increasing number of immunosuppressed individuals. The accidental or permanent presence of fungi in animals, plants, soils and watercourses should not be taken too lightly because they constitute the source where potential pathogens will be contracted. If those fungal habitats that carry the largest risks of exposure could be defined, if seasonal variations in the production of infectious propagules could be determined, and if their mode of transmission were to be assessed, it would be possible to develop protective measures in order to avoid human infection. Additionally, unsuspected avenues for the exploration of fungal survival strategies would be opened, thus enhancing our capacity to react properly to their advancing limits. This paper explores several ecological connections between human pathogenic fungi and certain animals, trees, waterways and degraded organic materials. The occurrence of such connections in highly endemic areas will hopefully furnish more precise clues to fungal habitats and allow the design of control programs aimed at avoiding human infection.

Animals↗

PubMed1999

Chronic pulmonary histoplasmosis in the State of Rio de Janeiro, Brazil.

Three cases of chronic pulmonary histoplasmosis affecting aged patients with chronic obstructive pulmonary disease are reported. They had a history of recurrent episodes of respiratory infection and presented radiological lung lesions inducing a misdiagnosis of chronic pulmonary tuberculosis of the adults. The diagnosis of histoplasmosis, suggested by the immunodiffusion test and the detection of yeastlike cells in smeared and stained sputum, was confirmed by the isolation and identification of Histoplasma capsulatum var. capsulatum in selective media. The treatment was carried out with amphothericin B and ketoconazole or itraconazole. Clinical, radiologic, mycologic and serologic improvement was obtained in all the patients. However, relapses occurred within a period of 1 to 18 months after the interruption of the treatment. Mycological diagnosis and the difficulties observed in the treatment were discussed. In addition data on the epidemiology of histoplasmosis in the state of Rio de Janeiro, Brazil, were presented.

Aged↗

PubMed1999

Investigation of an outbreak of endemic coccidioidomycosis in Brazil's northeastern state of Piauí with a review of the occurrence and distribution of Coccidioides immitis in three other Brazilian states.

An outbreak of coccidioidomycosis is described that involved three individuals and eight of their dogs, who had engaged in a successful hunt for nine-banded armadillos (Dasypus novemcinctus) in the environs of Oeiras, a community in Brazil's north eastern state of Piauí. Diagnosis was based on clinical, serological and cultural findings. Four of 24 soil samples collected in and around the burrow of an armadillo yielded cultures of Coccidioides immitis, thus establishing the endemicity of that mould in the state of Piauí. A literature review revealed that C. immitis, aside from that state, is endemic in three other Brazilian states--Bahia, Ceará and Maranhão. These four contiguous states have semi-arid regions where climatic conditions and their flora are similar to those that exist in C. immitis's endemic regions in North, Central and South America.

Adult↗

PubMed1999

Paracoccidioidomycosis.

Paracoccidioidomycosis is a systemic infection caused by the dimorphic fungus Paracoccidioides brasiliensis. It is commonly an endemic disease in Latin America, but several cases have been reported outside this area, particularly now in this time of world globalization. Primary pulmonary infection occurs commonly in the first and second decades of life and usually has a benign, self-limited respiratory infection course. The adult chronic manifestation of the disease is usually the result of reactivation of quiescent lesions with diffuse lung infiltrates, predominately of the interstitial pattern, with or without involvement of various other organs. The finding of this disease in a patient is an important step for the large differential diagnosis of the interstitial lung diseases group.

Adolescent↗

PubMed1998

Cryptococcus neoformans isolated from human dwellings in Rio de Janeiro, Brazil: an analysis of the domestic environment of AIDS patients with and without cryptococcosis.

One hundred and fifty-four human dwellings in the metropolitan area of Rio de Janeiro, Brazil were studied. A total of 824 samples of indoor dust, outdoor soil and avian droppings were collected. Cryptococcus neoformans var. neoformans was isolated from 20 (13%) dwellings, comprising five (15.6%) of 32 dwellings of patients with AIDS-associated cryptococcosis; four (8.9%) of 45 dwellings of patients with AIDS but without cryptococcosis; and 11 (14.3%) of 77 dwellings of apparently healthy individuals (P>0.05). The principal factor associated with domiciliar contamination by C. neoformans var. neoformans was the presence of avians in the domestic environment or nearby the home. Cryptococcosis was more frequent among AIDS patients residing in dwellings from which C. neoformans var. neoformans was isolated than among AIDS patients from whose domestic environment the fungus was not demonstrated by the methods used (odds ratio (OR)=2.05). These findings suggest that the distribution of C. neoformans var. neoformans in Rio de Janeiro is not restricted to the classically known biotopes as well as reinforce the possibility of exogenous infection in opportunistic cryptococcosis, including exogenous infection acquired in the domestic environment.

AIDS-Related Opportunistic Infections↗

PubMed1998

Cryptococcus neoformans var. gattii--evidence for a natural habitat related to decaying wood in a pottery tree hollow.

To study hollows of living trees as the natural habitat of Cryptococcus neoformans in an endemic area of cryptococcosis in the northeastern Brazilian region, samples of decaying wood were collected inside the hollows, plated on niger seed agar and inoculated into mice and hamsters. Identification of C. neoformans was based on morphological and physiological tests. Canavanine-glycine-bromothymol medium was used to screen the varieties and Crypto Check Iatron Kit to serotype the isolates. For a period of 29 months C. neoformans var. gattii serotype B was isolated repeatedly from the hollow of a pottery tree (Moquilea tomentosa), pointing to the natural occurrence of C. neoformans var. gatti in decaying wood forming hollows in living trees. Evidence for a natural habitat of the variety gattii other than that related to Eucalyptus camaldulensis are discussed.

Animals↗