RESUMO
Cryptococcus isolates from Cuban patients were identified as C. neoformans var. grubii. Although this species has since long been associated with bird droppings, a recent genotyping study provided strong evidence for additional origins of exposure. We sampled different species of trees in Havana, Cuba to identify other potential sources of exposure to this fungus. A total of 662 samples were collected from 331 trees and cacti from Havana, Cuba. Initial selection of the isolates was carried out by conventional techniques. Isolates were further characterised using a combination of AFLP analysis and DNA sequence analysis. Identification by conventional methods yielded 121 C. neoformans and 61 C. gattii isolates. Molecular analyses showed that none of these isolates was C. gattii and only one isolate proved to be C. neoformans var. grubii. A total of 27 different other species were identified. The most prevalent species was C. heveanensis (33%). Sixty-five unidentifiable isolates segregated into ten potentially novel species. Conventional cultivation methods have a low specificity for C. neoformans complex and molecular analyses need to be applied to confirm identification of isolates from environmental sources. Environmental niches responsible for most of human cryptococcal infections in Cuba remain to be identified.
Assuntos
Cryptococcus/isolamento & purificação , Microbiologia Ambiental , Árvores/microbiologia , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Criptococose/microbiologia , Cryptococcus/classificação , Cryptococcus/genética , Cuba , Humanos , FilogeniaAssuntos
Acinonyx/microbiologia , Criptococose/veterinária , Cryptococcus gattii/isolamento & purificação , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Animais , Animais de Zoológico , Criptococose/microbiologia , Criptococose/patologia , Cryptococcus gattii/classificação , Cryptococcus gattii/genética , Cuba , DNA Fúngico/genética , Tipagem Molecular , Técnicas de Tipagem Micológica , RecidivaRESUMO
5-fluorocytosine has been one of the most used antimycotics in the therapeutics of mycosis, however the appearance of resistant strains may be an important limitant for its use. That's why it is necessary to know the sensitivity to this drug. To this end, it was determined the minimum inhibitory concentration (MIC) of 5-fluorocytosine against 50 clinical isolates of Candida albicans by a micromethod of dilution in RPMI 1640 media, comparing 2 reading methods. The values of the geometrical mean obtained were 0.95 mg/mL for the visual reading and 0.75 mg/mL for the automated reading. There were no significant differences between them (p < 0.05). Pearson's lineal correlation coefficient was r = 0.81. It indicates that although there was a good correlation, there was also discrepancy between both readings. The IMC50 was of 0.5 microgram/mL and the IMC90 of 4 mg/mL. 90 and 92% of sensitive strains, between 6 and 8% of resistant strains and 2% of strains with intermediate sensitivity were found depending on the reading method used. These values show a low resistance against this drug, which may have a direct repercussion on the therapeutic behaviour to be followed in candidiasis.
Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Flucitosina/farmacologia , Humanos , Testes de Sensibilidade MicrobianaRESUMO
The minimum inhibitory concentration of fluconozole was determined in 36 strains of Cryptococcus neoformans var. neoformans by a casitone broth microdilution method, taking into account that it is one of the most used antifungal agents in our country for the treatment of cryptococcal meningitis, the second opportunistic mycosis in order of frequency and that with the highest lethality among AIDS patients. The minimum inhibitory concentration of the studied strains ranged 0.125 to more than 64 micrograms/mL for a geometrical mean of 2.38 micrograms/mL. 50% of the strains were inhibited with 4 micrograms/mL and the least concentration that inhibited 90% was 16 micrograms/mL. It is stressed the importance of continuing this type of in vitro studies to detect the appearance of resistance of C. neoformans to antifungal agents.
Assuntos
Antifúngicos/farmacologia , Cryptococcus neoformans/efeitos dos fármacos , Fluconazol/farmacologia , Humanos , Testes de Sensibilidade MicrobianaRESUMO
In order to know the sensitivity of Candida and Crytococcus to amphotericin B, main drug for the treatment od systemic mycosis, it was determined the minimum inhibitory concentration (MIC) in 90 clinical isolates of Candida and Crytococcus by a micromethod for the broth dilution. According to the results, Crytococcus neoformas was more sensitive then Candida albicans (geometrical means 0.24 and 0.41 respectively). Only one resistant strain was found (CMI = 16 micrograms/mL), corresponding to the Candida krusei species. The introduction of this technique in the Mycology Laboratory of the "Pedro Kourí" Institute of Tropical Medicine will allow to establish the sensitivity patterns and to detect the possible appearance of resistance in the main species of pathogenic fungus for men in our environment.
Assuntos
Anfotericina B/administração & dosagem , Candida/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Anfotericina B/farmacologia , Humanos , Masculino , Testes de Sensibilidade MicrobianaRESUMO
18 AIDS patients who presented high gastrointestinal symptoms or lesions in the oral cavity suggestive of candidiasis were studied. Clinical data, specimen of the oral cavity, biopsies and esophageal brushing, as well as serum from all patients were obtained. Dysphagia was the main symptom observed in the esophageal candidiasis. Candida albicans was the most isolated species with a predominance of serotype A. The protein profiles of 12 strains belonging to this species were analyzed by the polyacrylamide gel electrophoresis, and it was found that their molecular weight patterns were identical, which indicates that the same strain is in the oral cavity and in the esophagus. The response of the anti-C. albicans antibodies was evaluated. The double immunodiffusion was not useful for the diagnosis of esophageal candidiasis.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Candidíase/microbiologia , Doenças do Esôfago/microbiologia , HIV-1 , Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Anticorpos Antifúngicos/análise , Candida/classificação , Candida/imunologia , Candida/isolamento & purificação , Candidíase/diagnóstico , Bochecha , Eletroforese em Gel de Poliacrilamida , Doenças do Esôfago/diagnóstico , Esôfago/microbiologia , Humanos , Mucosa Bucal/microbiologia , SorotipagemRESUMO
50 strains of Cryptococcus neoformans of clinical origin were studied by using the canavanine-glycine-bromothymol blue (CGB) medium. 56% of the strains were isolated from AIDS patients, and 16% belonged to patients with kidney transplantation. 90% of the samples were obtained from the samples of cerebrospinal fluid, which corresponded to the classical form of presentation of cryptococcosis. All the strains were identified as C. neoformans var. neoformans, coinciding with previous reports made in Cuba. Knowing the varieties of C. neoformans, inferences can be drawn on the epidemiology, clinics and response to the treatment of cryptococcosis.
Assuntos
Cryptococcus neoformans/isolamento & purificação , Síndrome da Imunodeficiência Adquirida/líquido cefalorraquidiano , Síndrome da Imunodeficiência Adquirida/microbiologia , Líquido Cefalorraquidiano/microbiologia , Cryptococcus neoformans/classificação , Cuba , Meios de Cultura , HIV-1 , Humanos , Transplante de RimRESUMO
A study of oral candidiasis was conducted among 25 HIV-positive and AIDS patients. The predominant clinical form of presentation was the pseudomembranous one, whereas the most frequently yeast species found in the isolations were: Candida albicans (54.1%), Candida tropicalis (8.1%), and Torulopsis glabrata (8.1%). It was demonstrated that patients with recurrent infections have colonization of the oral cavity by multiple strains and/or yeast species more often (30.8%) than those through their first episode of oral candiadisis (12.5%). Of the 3 culture media used for the initial isolation, the combination of the potatodextrose agar (PDA) with Sabouraud triphenytletrazolium agar (STA) allowed to obtain the maximum isolation and differentiation among strains. The Sabouraud agar (SA), the most used medium to these ends at the international level, proved to be less useful than the previous ones. The STA was very efficient in the studies of phenotypic typing of most of the isolated yeast species and specially of C. albicans, which will make possible to approach epidemiological studies.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Candida/isolamento & purificação , Candidíase Bucal/microbiologia , Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Candida/classificação , Candida albicans/isolamento & purificação , Candidíase Bucal/epidemiologia , Cuba/epidemiologia , Humanos , Micoses/epidemiologia , Micoses/microbiologia , Trichosporon/isolamento & purificaçãoRESUMO
The clinical histories of 12 AIDS patients whose histoplasmosis diagnosis has been confirmed by histopathological studies were reviewed aimed at knowing the main clinical and microbiological aspects of the disseminated progressive histoplasmosis. In every case it appeared as a febrile and waste disease with an elevated hepatomegaly frequency and generalized adenopathies. More than 50% of the patients had anemia and an accelerated erythrocyte sedimentation. The chest X-ray showed pulmonary lesions in 50% of the patients, whereas, the abdominal ultrasound allowed to observe hepatomegaly and splenomegaly in 58.3 and 41.6% of the patients, respectively. A low sensitivity was found in the culture of different clinical specimens as well as in the antibody detection techniques. It is discussed the need to improve tha laboratory diagnosis methods, particularly those which make possible the antigen detection in a fast and specific way.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , HIV-1 , Histoplasmose/diagnóstico , Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Adolescente , Adulto , Anticorpos Antifúngicos/sangue , Contagem de Linfócito CD4 , Progressão da Doença , Feminino , Histoplasma/imunologia , Histoplasma/isolamento & purificação , Histoplasmose/microbiologia , Humanos , Masculino , Estudos RetrospectivosRESUMO
Aspergillosis became an important opportunistic mycosis during the last years, with a great variety of clinical manifestations. To contribute to the replenishing of this mycosis serodiagnosis, biologic reactives (antigens and antisera) were prepared from strains of the species Aspergillus niger, Aspergillus flavus and Aspergillus terreus for their use in immunoprecipitation assays. The reactives were assessed by double immunospreading versus a reference commercial system; satisfactory results were obtained, and this guarantees the widening of the aspergillosis serodiagnosis in the Mycology Laboratory of the "Pedro Kourí" the Tropical Medicine Institute (IPK) with important imports savings.