ABSTRACT
Cryptococcus neoformans is one of the medically important yeast-like fungi. C. neoformans var. gatti has been made a species: C. gatti. In our country, there are few studies about these two species and their serotypes. The aim of this study was to determine the distribution of C. neoformans and C. gattii, and their serotypes in Venezuelan clinical isolates. One hundred and twenty C. neoformans and 12 C. gattii clinical isolates were identified by L-canavanine, glycine, and bromothymol blue agar media (CGB). These were investigated by agglutination and adsorption studies with anticryptococcal sera, which were produced by rabbit immunization. Of the 132 isolates 59.8% were typed serotype A (C. neoformans), followed by 25.8% serotype D (C. neoformans), 5.3% serotype AD (C. neoformans), and 5.3% were typed serotype C (var. gattii). Additionally 3.8% were serotype B (C. gattii).
Subject(s)
Cryptococcosis/epidemiology , Cryptococcosis/microbiology , Cryptococcus neoformans/classification , Cryptococcus/classification , Animals , Cryptococcus/isolation & purification , Cryptococcus neoformans/isolation & purification , Culture Media , Humans , Immunization , Mycological Typing Techniques , Rabbits , Serotyping , Species Specificity , Venezuela/epidemiologyABSTRACT
Faecal samples from 123 children admitted to the Centre for Tropical Diseases in Ho Chi Minh city, Vietnam, with acute watery diarrhoea were screened by negative-stain electron microscopy for viral enteropathogens. In addition to the 48 children who were found to be infected with rotavirus only, one had both rotavirus and astrovirus, two had adenovirus 40/41, and one had astrovirus only. The rotaviruses were subjected to molecular analysis by electropherotyping, G- and P-genotyping (by reverse-transcriptase PCR), and amplicon sequencing. By use of newly designed PCR primers, all 49 isolates could be G-genotyped and all but one P-genotyped. Novel variants of G1-G1*--were the most commonly detected G-genotype and such variants of P[8]-P[8*]--were the second commonest P-genotype. The P[8*] and G1* amplicons were, respectively, only 92%-93.4% and 88.1%-89% similar to the corresponding sequences from the prototype P[8] G1 rotavirus, Wa. Several unusual P- and G-genotype combinations were detected. Four (8%) of the children investigated were each found to be co-infected with two different rotaviruses. These data add to our knowledge of the continuing evolution and diversity of human rotaviruses, and should help in the rational design of vaccines.
Subject(s)
Diarrhea/virology , Rotavirus/isolation & purification , Adenoviridae/isolation & purification , Base Sequence , Child, Preschool , Diarrhea/epidemiology , Electrophoresis, Polyacrylamide Gel/methods , Genotype , Humans , Mamastrovirus/isolation & purification , Microscopy, Electron/methods , RNA, Viral/analysis , Reverse Transcriptase Polymerase Chain Reaction/methods , Rotavirus/genetics , Vietnam/epidemiologyABSTRACT
In pathogenicity studies of 31 Paracoccidioides brasiliensis isolates preserved using Castellani's method we intraperitoneally inoculated 104 young adult hamsters and found laminated concentric structures and calcified appearance that resembled Schaumann bodies, in 43 of them, especially in animals with apparently good condition. We characterized these structures histologically and histochemically using different stains (PAS, Grocott, haematoxylin-eosin, Von Kossa). The Von Kossa staining revealed calcium in these structures. Similar structures have been described in patients with sarcoidosis and also in hamsters inoculated with P. brasiliensis. We found no correlation between the presence of these calcifications and serum calcium levels.