Cryptococcus neoformans and Cryptococcus gattii are responsible globally for almost one million cryptococcosis cases yearly, mostly in immunocompromised patients, such as those living with HIV. Infections due to C. gattii have mainly been described in tropical and subtropical regions, but its adaptation to temperate regions was crucial in the species evolution and highlighted the importance of this pathogenic yeast in the context of disease. Cryptococcus gattii molecular type VGII has come to the forefront in connection with an on-going emergence in the Pacific North West of North America. Taking into account that previous work pointed towards South America as an origin of this species, the present work aimed to assess the genetic diversity within the Brazilian C. gattii VGII population in order to gain new insights into its origin and global dispersal from the South American continent using the ISHAM consensus MLST typing scheme. Our results corroborate the finding that the Brazilian C. gattii VGII population is highly diverse. The diversity is likely due to recombination generated from sexual reproduction, as evidenced by the presence of both mating types in clinical and environmental samples. The data presented herein strongly supports the emergence of highly virulent strains from ancestors in the Northern regions of Brazil, Amazonia and the Northeast. Numerous genotypes represent a link between Brazil and other parts of the world reinforcing South America as the most likely origin of the C. gattii VGII subtypes and their subsequent global spread, including their dispersal into North America, where they caused a major emergence.
AIM: The aim of the present study was to evaluate the diet and biological attributes of the population of Apareiodon affinis residing near net-cage fish farming activities in the Chavantes reservoir. METHODS: Samples were collected from two populations: one near the net cages (NC) and one from an area not influenced by these cages denominated the "reference site" (RS). Monthly sampling was carried out from Mar/2008 to Feb/2009. Fish were caught with a standardized effort using gill nets deployed for 14 hours. After all individuals were measured (standard length) and weighed (total weight, carcass weight , body weight without gonads). To determine the composition of the diet, the alimentary index was calculated (AI). We also calculated the length-weight relationship, condition factor, gonad-somatic index (GSI ) and reproductive potential. RESULTS: A total of 3050 individuals were caught. The results of the (AI) revealed that the item detritus was the main food used for populations of A. affinis studied in two areas (NC = 73.1% and RS = 95.7%). The use of feed on diet A. affinis was recorded for the populations of NC adding (20.5%) of the total items consumed by the population. The resident populations residing near net-cage showed higher condition factor and more reproductive period. CONCLUSIONS: The results show the ability of the species to benefit from the input of organic matter from fish farming activities, inserting a new item in their diet (ration). This work indicates that the species A. affinis managed to establish near net-cage, allocating enough energy to increase their reproductive period and maintain viable populations close to net-cage, evidenced by the high abundance. This study suggests that systems of fish farming in net-cage influence diet and biological attributes of the species A. affinis residents Chavantes reservoir, Brazil.
Background In Brazil, malaria is concentrated in the Amazon Basin, where more than 99% of the annual cases are reported. The main goal of this study was to investigate the population structure and genetic association of the biting behavior of Nyssorhynchus (also known as Anopheles) darlingi, the major malaria vector in the Amazon region of Brazil, using low-coverage genomic sequencing data. Methods Samples were collected in the municipality of Mâncio Lima, Acre state, Brazil between 2016 and 2017. Different approaches using genotype imputation and no gene imputation for data treatment and low-coverage sequencing genotyping were performed. After the samples were genotyped, population stratification analysis was performed. Results Weak but statistically significant stratification signatures were identified between subpopulations separated by distances of approximately 2–3 km. Genome-wide association studies (GWAS) were performed to compare indoor/outdoor biting behavior and blood-seeking at dusk/dawn. A statistically significant association was observed between biting behavior and single nucleotide polymorphism (SNP) markers adjacent to the gene associated with cytochrome P450 (CYP) 4H14, which is associated with insecticide resistance. A statistically significant association between blood-seeking periodicity and SNP markers adjacent to genes associated with the circadian cycle was also observed. Conclusion The data presented here suggest that low-coverage whole-genome sequencing with adequate processing is a powerful tool to genetically characterize vector populations at a microgeographic scale in malaria transmission areas, as well as for use in GWAS. Female mosquitoes entering houses to take a blood meal may be related to a specific CYP4H14 allele, and female timing of blood-seeking is related to circadian rhythm genes. Graphical Abstract
In this study, the inverted trophic hypothesis was tested in the freshwater fish communities of a reservoir. The distribution of fish species in three freshwater habitats in the Jurumirim Reservoir, Brazil, was examined using both species richness and the relative proportions of different trophic groups. These groups were used as a proxy for functional structure in an attempt to test the ability of these measures to assess fish diversity. Assemblage structures were first described using non‐metric multidimensional scaling (NMDS). The influence of environmental conditions for multiple fish assemblage response variables (richness, total abundance and abundance per trophic group) was tested using generalised linear mixed models (GLMM). The metric typically employed to describe diversity; that is, species richness, was not related to environmental conditions. However, absolute species abundance was relatively well explained with up to 54% of the variation in the observed data accounted for. Differences in the dominance of trophic groups were most apparent in response to the presence of introduced fish species: the iliophagous and piscivorous trophic groups were positively associated, while detritivores and herbivores were negatively associated, with the alien species. This suggests that monitoring functional diversity might be more valuable than species diversity for assessing effects of disturbances and managements policies on the fish community.
First record of the "cascudo", Loricariichthys platymetopon Isbrücker and Nijssen, 1979 in Canoas II Reservoir (Middle Paranapanema River, border of the states of São Paulo and Paraná, Brazil). Its occurrence is due to the flooding of Sete Quedas waterfall, as a result of the construction of Itaipu Reservoir. Furthermore, there is absence or low abundance of natural predators, like Salminus brasiliensis, since this species has difficulties to adapt or even survive in reservoirs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.