Search

• MAYV RNA synthesis starts at 2hpi, Morphogenesis at 3hpi and Liberation at 4hpi. • Ribosome reorganization precedes early morphogenesis/liberation of particles. • Clusters of nucleocapsid-like structures are related with early morphogenesis. • CPV-II formation was correlated with exponential increase of virus particles. • Timeline of events of MAYV replication was established. Mayaro virus (MAYV) is mainly found in Central and South America and causes a febrile illness followed by debilitating arthritis and arthralgia similar to chikungunya virus (CHIKV). Infection leads to long-term sequelae with a direct impact on the patient's productive capacity, resulting in economic losses. Mayaro fever is a neglected disease due to the limited epidemiological data. In Brazil, it is considered a potential public health risk with the number of cases increasing every year. Most of our knowledge about MAYV biology is inferred from data obtained from other alphaviruses as well as more recent studies on MAYV. Here, we analyzed the kinetics of viral replication through standard growth curves, quantification of intracellular and extracellular particles, and RNA quantification. We compared transmission electron microscopy data during different stages of infection. This approach allowed us to establish a chronological order of events during MAYV replication and its respective timepoints including cell entry through clathrin-mediated endocytosis occurring at 15-30 min, genome replication at 2-3 h, morphogenesis at 4 hpi, and release at 4-6 hpi. We also present evidence of uncharacterized events such as ribosome reorganization as well as clusters of early viral precursors and release through exocytosis in giant forms. Our work sheds new and specific light on the MAYV replication cycle and may contribute to future studies on the field [Display omitted] [ABSTRACT FROM AUTHOR]

A novel viral disease of melon, caused by Melon yellowing-associated virus (MYaV), has become one of the most serious problems for melon production in Brazil. Despite its importance, little is known about the genome sequence of the virus. In this study, the triple gene block genomic region including the 3′-end region of an isolate of MYaV was elucidated (ca. 3.1 kb). Sweet potato chlorotic fleck virus, a newly suggested carlavirus species, was the most closely related virus with 62% nucleotide identity. The presence of two heptanucleotide-motifs for subgenomic RNA synthesis was confirmed in this sequence. [ABSTRACT FROM AUTHOR]

In tropical soils, diversity and biotechnological potential of symbiotic diazotrophic bacteria are high. However, the phylogenetic relationships of prominent strains are still poorly understood. In addition, in countries such as Brazil, despite the broad use of rhizobial inoculants, molecular methods are rarely used in the analysis of strains or determination of inoculant performance. In this study, both rep-PCR (BOX) fingerprintings and the DNA sequences of the 16S rRNA gene were obtained for 54 rhizobial strains officially authorized for the production of commercial inoculants in Brazil. BOX-PCR has proven to be a reliable fingerprinting tool, reinforcing the suggestion of its applicability to track rhizobial strains in culture collections and for quality control of commercial inoculants. On the other hand, the method is not adequate for grouping or defining species or even genera. Nine strains differed in more than 1.03% (15) nucleotides of the 16S rRNA gene in relation to the closest type strain, strongly indicative of new species. Those strains were distributed across the genera Burkholderia, Rhizobium, and Bradyrhizobium. [ABSTRACT FROM AUTHOR]