Development of an RT-qPCR assay for the specific detection of a distinct genetic lineage of the infectious bursal disease virus

The infectious bursal disease virus (IBDV) is a major health threat to the world’s poultry industry despite intensive controls including proper biosafety practices and vaccination. IBDV (Avibirnavirus, Birnaviridae) is a non-enveloped virus with a bisegmented double-stranded RNA genome. The virus is traditionally classified into classic, variant and very virulent strains, each with different epidemiological relevance and clinical implications. Recently, a novel worldwide spread genetic lineage was described and denoted as distinct (d) IBDV. Here, we report the development and validation of a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay for the specific detection of dIBDVs in the global poultry industry. The assay employs a TaqMan-MGB probe that hybridizes with a unique molecular signature of dIBDV. The assay successfully detected all the assessed strains belonging to the dIBDV genetic lineage, showing high specificity and absence of cross-reactivity with non-dIBDVs, IBDVnegative samples and other common avian viruses. Using serial dilutions of in vitro-transcribed RNA we obtained acceptable PCR efficiencies and determination coefficients, and relatively small intra- and inter-assay variability. The assay demonstrated a wide dynamic range between 103 and 108 RNA copies/reaction. This rapid, specific and quantitative assay is expected to improve IBDV surveillance and control worldwide and to increase our understanding of the molecular epidemiology of this economically detrimental poultry pathogen

A deletion in SARS-CoV- 2 ORF7 identified in COVID-19 outbreak in Uruguay

The analysis of genetic diversity in SARS-CoV-2 is the focus of several studies, providing insights into how the virus emerged and evolves. Most common changes in SARS-CoV-2 are single or point nucleotide substitutions; meanwhile, insertions and deletions (indels) have been identified as a less frequent source of viral genetic variability. Here, we report the emergence of a 12-nucleotide deletion in ORF7a, resulting in a 4-amino acid in-frame deletion. The Δ12 variant was identified in viruses from patients of a single outbreak and represents the first report of this deletion in South American isolates. Phylogenetic analysis revealed that Δ12 strains belong to the lineage B.1.1 and clustered separated from the remaining Uruguayan strains. The ∆12 variant was detected in 14 patients of this outbreak by NGS sequencing and/or two rapid and economic methodologies: Sanger amplicon sequencing and capillary electrophoresis. The presence of strong molecular markers as the deletion described here are useful for tracking outbreaks and reveal a significant aspect of the SARS-CoV-2 evolution on the robustness of the virus to keep its functionality regardless loss of genetic material

Genome sequences of SARS-CoV-2 P.1 (Variant of Concern) and P.2 (Variant of Interest) identified in Uruguay

Two severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants associated with increased transmission and immune evasion, P.1 and P.2, emerged in Brazil and spread throughout South America. Here, we report genomes corresponding to these variants that were recently detected in Uruguay. These P.1 and P.2 genomes share all substitutions that are characteristic of these variants

Research Note: high genetic diversity of infectious bronchitis virus from Mexico

The avian infectious bronchitis virus (IBV) is a highly mutable coronavirus that causes an acute and highly contagious disease responsible for economic losses to the poultry industry worldwide. Preventing and controlling bronchitis disease is difficulted by the numerous IBV circulating types with limited antigenic cross rotection that hamper the prevention and control by heterologous vaccines. The coding region of the variable spike S1 receptor-attachment domain is used to classify IBV in 7 genotypes (GI–GVII) comprising 35 viral lineages (1–35). Knowledge of the circulating IBV types causing outbreaks in a specific geographic region is beneficial to select better the appropriate vaccine(s) and contribute to disease control. In the study, 17 avian infectious bronchitis virus strains were obtained from chickens showing signs of illness in Mexico from 2007 to 2021. We detected 4 lineages within genotype I, three already known (GI-3, GI-9, GI-13) and one newly described (GI-30). In addition, we identified 2 divergent monophyletic groups that are tentatively described as lineages of new genotypes (GVIII-1 and GIX-1). Our findings revealed that Mexico's high genetic IBV diversity results from the co-circulation of divergent lineages belonging to different genotypes. Mexican IBV lineages differ significantly from Massachusetts and Connecticut vaccine strains, indicating that the currently used vaccines may need to be updated

Transmission cluster of COVID-19 cases from Uruguay: emergence and spreading of a novel SARS-CoV-2 ORF6 deletion

BACKGROUND Evolutionary changes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) include indels in nonstructural, structural, and accessory open reading frames (ORFs) or genes. OBJECTIVES We track indels in accessory ORFs to infer evolutionary gene patterns and epidemiological links between outbreaks. METHODS Genomes from Coronavirus disease 2019 (COVID-19) case-patients were Illumina sequenced using ARTIC_V3. The assembled genomes were analysed to detect substitutions and indels. FINDINGS We reported the emergence and spread of a unique 4-nucleotide deletion in the accessory ORF6, an interesting gene with immune modulation activity. The deletion in ORF6 removes one repeat unit of a two 4-nucleotide repeat, which shows that directly repeated sequences in the SARS-CoV-2 genome are associated with indels, even outside the context of extended repeat regions. The 4-nucleotide deletion produces a frameshifting change that results in a protein with two inserted amino acids, increasing the coding information of this accessory ORF. Epidemiological and genomic data indicate that the deletion variant has a single common ancestor and was initially detected in a health care outbreak and later in other COVID-19 cases, establishing a transmission cluster in the Uruguayan population. MAIN CONCLUSIONS Our findings provide evidence for the origin and spread of deletion variants and emphasise indels’ importance in epidemiological studies, including differentiating consecutive outbreaks occurring in the same health facility

Consecutive deletions in a unique Uruguayan SARS-CoV-2 lineage evidence the genetic variability potential of accessory genes

Deletions frequently occur in the six accessory genes of SARS-CoV-2, but most genomes with deletions are sporadic and have limited spreading capability. Here, we analyze deletions in the ORF7a of the N.7 lineage, a unique Uruguayan clade from the Brazilian B.1.1.33 lineage. Thirteen samples collected during the early SARS-CoV-2 wave in Uruguay had deletions in the ORF7a. Complete genomes were obtained by Illumina next-generation sequencing, and deletions were confirmed by Sanger sequencing and capillary electrophoresis. The N.7 lineage includes several individuals with a 12-nucleotide deletion that removes four amino acids of the ORF7a. Notably, four individuals underwent an additional 68-nucleotide novel deletion that locates 44 nucleotides downstream in the terminal region of the same ORF7a. The simultaneous occurrence of the 12 and 68-nucleotide deletions fuses the ORF7a and ORF7b, two contiguous accessory genes that encode transmem- brane proteins with immune-modulation activity. The fused ORF retains the signal peptide and the complete Ig-like fold of the 7a protein and the transmembrane domain of the 7b protein, suggesting that the fused protein plays similar functions to original proteins in a single format. Our findings evidence the remarkable dynamics of SARS-CoV-2 and the possibility that single and consecutive deletions occur in accessory genes and promote changes in the genomic organization that help the virus explore genetic variations and select for new, higher fit changes

Apresentação

En esta oportunidad, la revista Cuadernos de Investigación Educativa presenta el monográfico: “Aportes de actualidad en investigación desde la perspectiva de la gestión”, en el que se ofrecen perspectivas relevantes de investigaciones de Uruguay, Chile, Brasil, Ecuador y Europa. El propósito principal de esta publicación es la difusión de procesos de investigación actualizados que hacen foco en la gestión educativa

Genome Sequence of a Distinct Infectious Bursal Disease Virus

Infectious bursal disease virus is a relevant avian pathogen that affects poultry production. Here, we report the full-length cod-ing sequence of the Uruguayan strain dIBDV/UY/2014/2202, isolated from a commercial broiler flock. The strain belongs to the distinct IBDV lineage that is widely distributed in South America

Technological characterisation of wood from Australian red cedar after first thinning of a plantation at five years

Australian red cedar (Toona ciliata M. Roem.) is a forest species planted in Brazil especially for lumber production. This study aimed to evaluate technological properties of the wood after selective first thinning of a plantation 5 years after planting. The technological properties evaluated were: (i) physical – apparent specific mass at 12% moisture content and shrinkage; (ii) mechanical – modulus of elasticity (E), modulus of rupture (σ), and brittleness; (iii) weathering; (iv) surface macrostructure – colour and roughness; (v) chemical – soluble and insoluble lignins, and holocellulose and ash contents; and vi) thermal – thermogravimetric analysis and calorific value. Apparent specific mass was 380 g m−3; the calculated shrinkage anisotropy of 1.04 and swelling anisotropy of 1.14 fit the classification ‘excellent quality’; the elasticity modulus was calculated as 4 700 MPa, and strength to flexion was 45 MPa. The mechanical properties other than brittleness were not compromised with weathering exposure. However, the accelerated weathering testing as a simulation of natural weathering showed modified colour of the wood and reduction of the mechanical properties. The calorific value of the wood (4 634.03 Kcal g−1) was similar to that reported for other fast-growing woods at even more advanced planting ages. Thermal stability of the wood was comparable to other fast-growing species used for energy purposes, owing especially to high holocellulose content. Keywords: accelerated weathering; calorific value; holocellulose; thermal stability; wood characteristic