Environmental isolation and characterisation of Cryptococcus species from living trees in Havana city, Cuba.

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.

[Esophageal candidiasis in AIDS patients. A clinical and microbiological study]. / Candidiasis esofágica en pacientes con SIDA. Estudio clínico y microbiológico.

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.

[The identification of Cryptococcus neoformans var. neoformans in Cuban clinical isolates]. / Identificación de Cryptococcus neoformans var. neoformans en aislamientos clínicos cubanos.

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.

[Isolation, identification, and typing of yeasts from HIV-positive patients with oral candidiasis]. / Aislamiento, identificación y tipificación de levaduras en pacientes VIH positivos con candidiasis oral.

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.

[The evaluation of antigens and antisera for their use in the serodiagnosis of aspergillosis]. / Evaluación de antígenos y antisueros para su utilización en el serodiagnóstico de aspergilosis.

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.