Federal University of Roraima

About: Federal University of Roraima is a based out in . It is known for research contribution in the topics: Population & Thermogravimetry. The organization has 981 authors who have published 1218 publications receiving 7849 citations. The organization is also known as: Federal University of Roraima.

Emergence of extensively drug-resistant international clone IC-6 Acinetobacter baumannii carrying blaOXA-72 and blaCTX-M-115 in the Brazilian Amazon region

Abstract: Objectives The extensively drug-resistant (XDR) Acinetobacter baumannii international clone VI (IC-6) has been identified worldwide since 2006. This study reports the emergence of IC-6 in the Brazilian Amazon region and reveals the particular genomic features considering its mobilome and resistome. Methods A total of 32 carbapenem-resistant A. baumannii strains recovered from Boa Vista city (Roraima, Brazil) in 2016 were characterised by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The whole genome sequences of the Brazilian IC-6 strains were obtained. The mobilome and resistome were assessed by in silico analyses. Results PFGE and MLST demonstrated that the 32 A. baumannii strains belonged to four clones. One XDR clone corresponded to the high-risk pandemic IC-6 lineage from ST944Oxf/78Pas. The IC-6 resistome was composed of aadA5, aac(3ʹʹ)-IIa, aph(3ʹ)-Ia, armA, aadB, msrE, blaTEM-1, IS15DIV–blaCTX-M-115–IS15DIV, blaOXA-90, ISAba1–blaADC-152, blaOXA-72, qacEΔ1 and sul1. Mobilome prediction revealed that blaOXA-72 was embedded in a 15.5-kb plasmid and that it was flanked by putative XerC/D-binding sites, possibly involved in blaOXA-72 mobilisation. Several resistance genes were in a 48-kb multidrug resistance genomic island inserted in the chromosome, which also harboured genes involved in host pathogenicity and adaptive traits. Interestingly, the Brazilian strains shared the blaOXA-72 and blaCTX-M-115 with IC-6/ST944Oxf/78Pas recovered in a distinct spatiotemporal context, pointing to an epidemiological link among them. Conclusion This study highlights the importance of surveillance of XDR A. baumannii strains, even outside of densely populated cosmopolitan regions, to reveal the epidemiology of pandemic lineages, stressing their threat to public health.

Origem, sucessão e estrutura de uma floresta de galeria periodicamente alagada em Viçosa-MG

Abstract: The study of the phytosociological structures and sizes in secondary forest fragments allows to make inferences on the original composition and structures at the beginning of the secondary succession. The importance of gallery or riparian forest studies increases with the increasing concerns on the impacts caused by water courses and their borders, specially the building of power plant dams. The objectives of this work were to describe the structure of a secondary gallery forest to identify an arboreous species population which participated at the beginning of the successional process in this forest and based on these data, to study the genetic structure and to assess the biology of the species which probably started the successional process. A survey of all the trees with a 1,3 m stem circumference from the ground greater than or equal to 10 cm was carried out. Out of the 48 tree species already included, 87.5% are endozoochoric and 12.5% are anemochoric. Out of the latter those with the smallest propagules presented greater density in this forest, which is isolated from others by pastures. The most important species (VI) presented by this gallery forest were: Talauma ovata, Erythrina falcata and Euterpe edulis. Ficus species from the subgenus Urostigma presented a great biomass in spite of its low density. Erythrina falcata was considered one of the species of greater importance, probably associated to the Ficus species at the beginning of the secondary succession, due to the structure of the stem diameters presented. In Erythrina falcata, the isoenzymatic systems of Isocitrate Dehydrogenase, Peroxidase, Phosphoglyco Mutase and Xiquimate Dehydrogenase were analyzed by means of zimograms. The population of 27 individuals of Erythrina falcata was found in Hardy-Weinberg balance, presenting a relatively high allelic diversity. The population of Erythrina falcata was found to be under biological and ecological conditions to start the secondary succession. The high genetic diversity of the Erythrina falcata population could be one of the determinant factors for the success of the colonization of the area. The association of Erythrina falcata with trees of the Ficus genus could have been determinant for the successful beginning of this process of colonization, and the initial association may have functioned as a low diversity system of species, comparable to other flooded forests of Southeastern Brazil.

Effect of different protocols for estrus synchronization on reproductive performance of Santa Inês ewes under Amazon environmental conditions

Abstract: . The objective of this study was to evaluate the effect of different hormonal protocols on the reproductive performance of Santa Ines ewes in Amazon environmental conditions. Twenty-two Santa Ines ewes between 3 and 4 years-old were distributed in a randomized block experimental design, where the treatments consisted of two protocols for estrus synchronization (short and long) with eleven animals each. Data on the occurrence of estrus were described for each protocol. Data of estrus, pregnancy, and prolificity were firstly subjected to ANOVA and a subsequent Tukey’s test. Results were considered significant at p ≤ 0.05. The short-term protocol presented an interesting successful rate, where above 70% ewes tested had estrus. The long-term protocol also achieved a high successful rate, where above 80% ewes tested had estrus. However, comparing the protocols, the long-term protocol presented better results of positive estrus and pregnancy rates in ewes. Thus, it can be concluded that both protocols presented satisfactory results regarding estrus manifestation, and prolificity (lambs produced per ewe). However, under Amazon environmental conditions, the long-term protocol presented better results regarding positive manifestation of estrus and pregnancy rate.

Ocorrência de fungos endofíticos "dark septate" em raízes de Oryza glumaepatula na Amazônia

Abstract: The objective of this work was to assess the occurrence of dark septate endophyte fungi (DSEF) in Oryza glumaepatula in Amazonia, and its in vitro colonization capacity. Oryza glumaepatula plants were collected in forest and cerrado areas of the Roraima state, Brazil. The roots were prepared to observe septate melanized hyphas and microesclerotia. The isolation of fungi was done in agar malte medium. Dark septate endophyte fungi were observed in plants from both environments, with higher colonization on those collected in the forest. One isolate was able to colonize the original host and also Oryza sativa plants, exhibiting typical DSEF structures in rice healthy plants.