Cloned tomato golden mosaic virus back in tomatoes.

Clones of tomato golden mosaic virus (TGMV), a key model for geminivirus research, have been transmitted back to their original host tomato for the first time. In contrast to the high pathogenicity in other solanaceous species, TGMV induced only very mild symptoms: a few chlorotic spots on the leaf lamina for the common variant (formerly strain cs), and limited vein yellowing for the yellow vein variant (yv). Symptoms disappeared over time, though viral DNA remained detectable in newly developed leaves.

Circular DNA genomics (circomics) exemplified for geminiviruses in bean crops and weeds of northeastern Brazil.

Circomics was coined to describe the combination of rolling circle amplification (RCA), restriction fragment length polymorphism (RFLP) and pyro-sequencing to investigate the genome structures of small circular DNAs. A batch procedure is described using 61 plant samples from Asia, South America and Central America which revealed 83 contig sequences of geminiviral DNA components and 4 contig sequences of DNA satellites. The usefulness of this approach is validated for the Brazilian begomoviruses, and the sequence fidelity is determined by comparing the results with those of conventional cloning and sequencing of Bolivian begomoviruses reported recently.

Phylogeny and polymorphism in the long control region, E6, and L1 of human papillomavirus types 53, 56, and 66 in central Brazil.

Introduction: Several studies related that different human papillomavirus (HPV) types and intratype variants can present different oncogenic potential. In opposite to HPVs 16 and 18 variants, information about variants of other carcinogenic HPV types is still scarce. The aim of this study was to investigate the genetic variability of HPVs 53, 56, and 66 from Central Brazil isolates.

The genomes of four novel begomoviruses and a new Sida micrantha mosaic virus strain from Bolivian weeds.

Begomovirus is the largest genus within the family Geminiviridae and includes economically important plant DNA viruses infecting a broad range of plant species and causing devastating crop diseases, mainly in subtropical and tropical countries. Besides cultivated plants, many weeds act as virus reservoirs. Eight begomovirus isolates from Bolivian weeds were examined using rolling-circle amplification (RCA) and restriction fragment length polymorphism (RFLP).

Genetic variability and phylogeny of the high-risk HPV-31, -33, -35, -52, and -58 in central Brazil.

More than 100 HPV types have been described, 13 of which are classified as high-risk due to their association with the development of cervical cancer. The intratype genomic diversity of HPV-16 and -18 has been studied extensively, while little data have been generated for other less common high-risk types. The present study explores the nucleotide variability and phylogeny of the high-risk HPV-31, -33, -35, -52, and -58, in samples from Central Brazil.

New HPV-16 European and non-European variants in Central Brazil.

HPV-16 is the most prevalent human papillomavirus genotype found in cervical intraepithelial neoplasias. The regulatory region of the HPV genome, LCR, has several binding sites for cellular and viral transcription factors, and nucleotide substitutions in this genomic region can interfere with the viral oncogenic expression. The present study aims to determine the LCR variability of European and non-European HPV-16 variants found in Brazil.

Hepatitis C virus genotypes in blood donors from the Federal District, Central Brazil.

The objective of this study was to characterize hepatitis C virus (HCV) genotypes in blood donors from the Federal District, Central Brazil, and to compare HCV screening by serological assays and reverse transcriptase polymerase chain reaction (RT-PCR). Plasma samples from 57 individuals with reactive or indeterminate results in serological anti-HCV screening assays (ELISA or EIA) were tested for HCV RNA by RT-PCR. The results from a confirmatory LIA serological assay were also evaluated.