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A comprehensive mathematical model is proposed to study two strains of dengue virus with saturated incidence rates and quarantine measures. Imperfect dengue vaccination is also assumed in the model. Existence, uniqueness and stability of the proposed model are proved using the results from fixed point and degree theory. Additionally, well constructed Lyapunov function candidates are also applied to prove the global stability of infection-free equilibria. It is also demonstrated that the model is generalized Ulam-Hyers stable under some appropriate conditions. The model is fitted to the real data of dengue epidemic taken from the city of Espirito Santo in Brazil. For the approximate solution of the model, a non-standard finite difference(NSFD) approach is applied. Sensitivity analysis is also carried out to show the influence of different parameters involved in the model. The behaviour of the NSFD is also assessed under different denominator functions and it is observed that the choice of the denominator function could influence the solution trajectories. Different scenario analysis are also assessed when the reproduction number is below or above one. Furthermore, simulations are also presented to assess the epidemiological impact of dengue vaccination and quarantine measures for infected individuals. [ABSTRACT FROM AUTHOR]

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The recent outbreak of Zika virus (ZIKV) in Brazil and other countries globally demonstrated the relevance of ZIKV studies. During and after this outbreak, there was an intense increase in scientific production on ZIKV infections, especially toward alterations promoted by the infection and related to clinical outcomes. Considering this massive amount of new data, mainly thousands of genes and proteins whose expression is impacted by ZIKV infection, the ZIKA Virus Infection Database (ZIKAVID) was created. ZIKAVID is an online database that comprises all genes or proteins, and associated information, for which expression was experimentally measured and found to be altered after ZIKV infection. The database, available at https://zikavid.org, contains 16,984 entries of gene expression measurements from a total of 7348 genes. It allows users to easily perform searches for different experimental hosts (cell lines, tissues, and animal models), ZIKV strains (African, Asian, and Brazilian), and target molecules (messenger RNA [mRNA] and protein), among others, used in differential expression studies regarding ZIKV infection. In this way, the ZIKAVID will serve as an additional and important resource to improve the characterization of the molecular impact and pathogenesis associated with ZIKV infection. [ABSTRACT FROM AUTHOR]

Grapevine rupestris stem pitting-associated virus (GRSPaV) is one of the most common viruses of grapevine. It is involved in the grafttransmissible disease rupestris stem pitting of the rugose wood complex. The objective of the research was to perform the molecular characterization of the coat protein (CP) gene of sixteen Brazilian GRSPaV isolates aiming to determine the occurrence of molecular variants (strains) of this virus. Nine grapevine samples were evaluated, from which dsRNA was extracted. Nucleotide sequences were generated by Next generation sequencing (NGS). Fifteen complete sequences of the GRSPaV CP gene were obtained and phylogenetically analyzed. Multiple alignments of the sequences showed identities of nucleotides ranging from 82% to 99%, suggesting high variability among the CPs of Brazilian isolates. The study revealed that genetic variability of GRSPaV comprising three molecular variants is also present in Brazilian grapevine genotypes. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The genetic variability of 19 Toxoplasma gondii strains isolated from humans and animals in Brazil was detected by both random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) and simple sequence repeat anchored-PCR (SSR-PCR) for the first time. Two reference strains, RH (highly virulent) and ME49 (avirulent), were submitted to both assays. Besnoitia sp., Plasmodium falciparum and Babesia bigemina were used as outgroups. RAPD-PCR and SSR-PCR profiles were used for building phenetic trees by unweighted pair group method with arithmetic averages (UPGMA). Phenograms built with TREECONW software showed great similarity in the topology of the trees. Both phenograms presented two major clusters that grouped T. gondii strains according to their murine virulence. The strains AS28, BV and N, which are highly virulent for BALB/c mice, were clustered with the reference strain RH, the highly virulent strain of T. gondii that has been most commonly studied. The group formed by the cystogenic strains showed that the strains which presented a level of virulence more similar to that of ME49 strain (avirulent) also presented a closer genetic relationship. Genetic variation within each lineage was significantly lower (P<0.05) than that between the lineages. Regarding outgroups, Besnoitia sp. presented the closest relationship to T. gondii while P. falciparum was the most distant. The results presented here demonstrate that intraspecific genetic variability separates Brazilian T. gondii strains into two groups which correlate with murine virulence phenotype. [Copyright &y& Elsevier]

The objective of this study was to identify Anaplasma marginale strains in dairy heifers from farms with a history of anaplasmosis in the northwest region of the State of Minas Gerais, Brazil. Among the examined animals of the four farms, the overall prevalence total of A. marginale was 55.7 % for gene msp5 and 36.7 % for blood smear. Thirty DNA samples (from 24 asymptomatic and six symptomatic animals) positive for A. marginale msp1α were sequenced to study genotype and strain diversity. The majority (28/30) were the E genotype, followed by C (1/30) and G (1/30). Thirteen different strains were found: α-β-F-F-F (nine animals), 13-27-27 (three animals), τ-27-18 (three animals), α-β-β- BRA1-31 (three animals), α- 22-1318 (three animals), 80-F-F- F-F (three animals), and α -22-13-13, α-β-β-Г, M-φ-φ-φ-φ-F, 42-25- 25-31, Q-Q-Q-M, B-Q-B-Q-B-M, and 16-17-F-F (one animal each). A new structure repeated in tandem was described and named BRA 1 (TDSSSASGVLSQSGQASTSSQLG). The α-β-F-F-F strain was present in all animals with acute anaplasmosis and in three animals asymptomatic. Thus, although 13 strains were observed in the animals evaluated, only the α-β-F-F-F strain was identified during occurrence of acute disease and mortality, we suggest that this strain has important pathogenicity for calves in northeastern Minas Gerais., (Copyright © 2020. Published by Elsevier GmbH.)

Schistosomiasis is a neglected disease with large geographic distribution worldwide. Among the several different species of this parasite, S. mansoni is the most common and relevant one; its pathogenesis is also known to vary according to the worms' strain. High parasitical virulence is directly related to granulomatous reactions in the host's liver, and might be influenced by one or more molecules involved in a specific metabolic pathway. Therefore, better understanding the metabolic profile of these organisms is necessary, especially for an increased potential of unraveling strain virulence mechanisms and resistance to existing treatments. In this report, MALDI-MSI and the metabolomic platform were employed to characterize and differentiate two Brazilian S. mansoni strains: males and females from Belo Horizonte (BH) and from Sergipe (SE). By performing direct analysis, it is possible to distinguish the sex of adult worms, as well as identify the spatial distribution of chemical markers. Phospholipids, diacylglycerols and triacylglycerols were located in specific structures of the worms' bodies, such as tegument, suckers, reproductive and digestive systems. Lipid profiles were found to be different both between strains and males or females, giving specific metabolic fingerprints for each group. This indicates that biochemical characterization of adult S. mansoni may help narrowing-down the investigation of new therapeutic targets according to worm composition, molecule distribution and, therefore, aggressiveness of disease., (Copyright © 2014 John Wiley & Sons, Ltd.)