RESUMO
Chamaecrista is a Pantropical legume genus of the tribe Cassieae, which includes six other genera. In contrast to most of the other Cassieae genera, Chamaecrista shows significant variability in chromosome number (from 2n = 14 to 2n = 56), with small and morphologically similar chromosomes. Here, we performed a new cytomolecular analysis on chromosome number, genome size, and rDNA site distribution in a molecular phylogenetic perspective to interpret the karyotype trends of Chamaecrista and other two genera of Cassieae, seeking to understand their systematics and evolution. Our phylogenetic analysis revealed that Chamaecrista is monophyletic and can be divided into four major clades corresponding to the four sections of the genus. Chromosome numbers ranged from 2n = 14, 16 (section Chamaecrista) to 2n = 28 (sections Absus, Apoucouita, and Baseophyllum). The number of 5S and 35S rDNA sites varied between one and three pairs per karyotype, distributed on different chromosomes or in synteny, with no obvious phylogenetic significance. Our data allowed us to propose x = 7 as the basic chromosome number of Cassieae, which was changed by polyploidy generating x = 14 (sections Absus, Apoucouita, and Baseophyllum) and by ascending dysploidy to x = 8 (section Chamaecrista). The DNA content values supported this hypothesis, with the genomes of the putative tetraploids being larger than those of the putative diploids. We hypothesized that ascending dysploidy, polyploidy, and rDNA amplification/deamplification are the major events in the karyotypic diversification of Chamaecrista. The chromosomal marks characterized here may have cytotaxonomic potential in future studies.
Assuntos
Chamaecrista , Fabaceae , Filogenia , Chamaecrista/genética , Fabaceae/genética , Cromossomos de Plantas/genética , Genoma de Planta , Cariótipo , Poliploidia , DNA Ribossômico/genéticaRESUMO
Mussel production is expanding worldwide, and in Brazil the main species currently produced is the mussel Perna perna. Bucephalid trematodes have been recorded in P. perna but their larval identification is problematic. In this context, the aims of this paper were to evaluate the prevalence of bucephalids in P. perna, perform taxonomic and phylogenetic trematode studies, and analyze potential histopathological alterations in the infected host. Mussels obtained by fishers from Guanabara Bay, Rio de Janeiro, Brazil were weighed and measured, and internal organ tissues and parasites were collected. Of the 69 analyzed mussels, 24.6 % (17/69) were parasitized by bucephalid larvae. Sporocysts were located mainly in host mantle. Mussels presented sporocysts and cercaria within the connective tissue of mantle, all without associated inflammatory reactions. Parasite loads varied from less than 5 % to > 50 % of parasitized tissue. Histopathological examinations indicated that male or female gonads were not observed in 77 % (10/13) of parasitized mussels and in 4 % (2/56) identified as non-parasitized in the histology but previously classified as parasitized in the stereomicroscopic analysis. Thus, the absence of gonads may be associated with parasitism. Prosorhynchoides sp. is reported herein for the first time in mussels sampled on the coast of Rio de Janeiro, with genetic and histological data reported for the intermediate host, sporocysts and cercariae. New 28S rDNA, 18S rDNA and ITS1, 5.8S and ITS2 sequences are provided.
Assuntos
Bivalves , Mytilidae , Perna (Organismo) , Trematódeos , Feminino , Masculino , Animais , Filogenia , Brasil , Bivalves/parasitologia , Trematódeos/genética , DNA Ribossômico/genéticaRESUMO
Bacterial resistance to antibiotics is a serious public health problem that needs new antibacterial compounds for control. Fungi, including resupinated fungi, are a potential source to discover new bioactive compounds efficient again to bacteria resistant to antibiotics. The inhibitory capacity against the bacterial species was statistically evaluated. All the species (basidiomata and strains) were molecularly characterized with the ITS1-5.8S-ITS2 barcoding marker. The strains Ceraceomyces sp., Fuscoporia sp., Gloeocystidiellum sp., Oliveonia sp., Phanerochaete sp., and Xenasmatella sp. correspond to resupinate Basidiomycetes, and only the strain Hypocrea sp. is an Ascomycete, suggesting contamination to the basidiome of Tulasnella sp. According to the antagonistic test, only the Gloeocystidiellum sp. strain had antibacterial activity against the bacterial species Escherichia coli of clinical interest. Statistically, Gloeocystidiellum sp. was significantly (<0.001) active against two E. coli pathotypes (O157:H7 and ATCC 25922). Contrarily, the antibacterial activity of fungi against other pathotypes of E. coli and other strains such as Serratia sp. was not significant. The antibacterial activity between 48 and 72 h increased according to the measurement of the inhibition halos. Because of this antibacterial activity, Gloeocystidiellum sp. was taxonomically studied in deep combined morphological and molecular characterization (ITS1-5.8S-ITS2; partial LSU D1/D2 of nrDNA). A new species Gloeocystidiellum lojanense, a resupinate and corticioid fungus from a tropical montane rainforest of southern Ecuador, with antibacterial potential against E. coli, is proposed to the science.
RESUMO
Abstract The present report describes the first case of postpartum disseminated histoplasmosis in a 24-year-old HIV-negative woman. On the tenth day after vaginal delivery, the patient presented with dyspnea, fever, hypotension, tachycardia, and painful hepatomegaly. Yeast-like Histoplasma capsulatum features were isolated in the buffy coat. The phylogenetic analysis demonstrated that the fungal isolate was similar to other H. capsulatum isolates identified in HIV patients from Ceará and Latin America. Thus, histoplasmosis development in individuals with transitory immunosuppression or during the period of immunological recovery should be carefully examined.
Assuntos
Humanos , Feminino , Adulto , DNA Fúngico/análise , DNA Espaçador Ribossômico/genética , Período Pós-Parto , Histoplasma/genética , Histoplasmose/diagnóstico , Filogenia , Reação em Cadeia da Polimerase , Histoplasma/isolamento & purificação , Histoplasmose/microbiologiaRESUMO
The objective of this study was to conduct a survey about fungi associated with leaves from two different maize plant lineages and to analyze their microbiota diversity. Isolated fungi were identified by morphological analysis and molecular taxonomy was performed using ITS1-5.8S-ITS2 rDNA. About 27 fungi morphotypes were obtained, 15 of them were from the first maize lineage. About 86.7% of the individuals belonged to the Dothideomycetes class (Phoma sorghina, Epicocum nigrum, Cladosporium sp., Bipolaris zeicola, and Alternaria alternata complex) and 13.3% to the Sordariomycetes class (Diaporthe/Phomopsis sp. and Nigrospora sp.). This ratio was opposite in the other maize lineage with 25.0% of Dothideomycetes (E. nigrum and Pleosporales) and 75.0% of Sordariomycetes (Gibberella fujikuroi complex, Fusarium graminearum complex, Diaporthe/Phomopsis sp., and Nigrospora sp.). By concerning the analyses of morphological characteristics and molecular phylogeny, this study intended to identify the groups of saprophytic, phytopathogenic, and mycotoxin fungi, which differently co-inhabit leaf tissue of maize plants in both tested lineages.
Assuntos
Endófitos/isolamento & purificação , Fungos/isolamento & purificação , Folhas de Planta/microbiologia , Zea mays/microbiologia , Biodiversidade , Brasil , Endófitos/classificação , Endófitos/genética , Fungos/classificação , Fungos/genética , Filogenia , Zea mays/crescimento & desenvolvimentoRESUMO
Yeasts of the genus Candida have high genetic variability and are the most common opportunistic pathogenic fungi in humans. In this study, we evaluated the genetic diversity among 120 isolates of Candida spp. obtained from diabetic patients, kidney transplant recipients and patients without any immune deficiencies from Paraná state, Brazil. The analysis was performed using the ITS1-5.8S-ITS2 region and a partial sequence of 28S rDNA. In the phylogenetic analysis, we observed a consistent separation of the species C. albicans, C. dubliniensis, C. glabrata, C. tropicalis, C. parapsilosis, C. metapsilosis and C. orthopsilosis, however with low intraspecific variability. In the analysis of the C. albicans species, two clades were formed. Clade A included the largest number of isolates (91.2%) and the majority of isolates from GenBank (71.4%). The phylogenetic analysis showed low intraspecific genetic diversity, and the genetic polymorphisms between C. albicans isolates were similar to genetic divergence found in other studies performed with isolates from Brazil. This low genetic diversity of isolates can be explained by the geographic proximity of the patients evaluated. It was observed that yeast colonisation was highest in renal transplant recipients and diabetic patients and that C. albicans was the species most frequently isolated.
Assuntos
Humanos , Masculino , Feminino , Candida/genética , Candidíase Invasiva/genética , Diabetes Mellitus/microbiologia , Variação Genética , Transplante de Rim , Brasil/epidemiologia , Candida/classificação , Candida/isolamento & purificação , Candidíase Invasiva/classificação , Candidíase Invasiva/epidemiologia , Candidíase Invasiva/microbiologia , Estudos de Casos e Controles , Complicações do Diabetes , DNA Fúngico/análise , DNA Ribossômico/genética , Testes de Sensibilidade MicrobianaRESUMO
The elongation factor 1-alpha (EF1-α) and the internal transcribed spacer (ITS) regions ITS1 and ITS2 (ITS1-5.8S-ITS2) sequences were used to characterize and to identify Isaria isolates from Argentina, Mexico, and Brazil, as well as to study the phylogenetic relationships among these isolates and other related fungi from the order Hypocreales. The molecular characterization, which was performed by PCR-RFLP of EF1-α and ITS1-5.8-ITS2 genes, was useful for resolving representative isolates of Isaria fumosorosea, Isaria farinosa, and Isaria tenuipes and to confirm the taxonomic identity of fungi from Argentina, Mexico, and Brazil. The phylogenetic analyses showed three clades corresponding to three families of Hypocreales. The genus Isaria was confirmed as polyphyletic and in family Cordycipitaceae, Isaria species were related to anamorphic species of Beauveria, Lecanicillium, and Simplicillium and to teleomorphic Cordyceps and Torrubiella. Therefore, EF1-α and ITS1-5.8S-ITS2 genes were found to be powerful tools for improving the characterization, identification, and phylogenetic relationship of the Isaria species and other entomopathogenic fungi.