Nanopore-based complete genome sequence of a Sri Lankan cassava mosaic virus (Geminivirus) strain from Thailand

Sri Lankan cassava mosaic virus is an emerging pathogen in Southeast Asia. Here, we report the complete genome of a Thai isolate obtained using Nanopore technology. The isolate was collected in 2019 from the northeastern province of Surin, soon after disease eradication was reported in the country

Genome sequence of SARS-CoV-2 isolate Cali-01, from Colombia, obtained using Oxford Nanopore MinION Sequencing

We report the genome sequence of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolate obtained from a patient with symptoms of coronavirus disease 2019 (COVID-19) who was infected in Cali, Colombia. The patient had no recent travel record and did not require hospitalization. The virus genome was obtained using Oxford Nanopore MinION sequencing

Comparatively Barcoded Chromosomes of Brachypodium Perennials Tell the Story of Their Karyotype Structure and Evolution

The Brachypodium genus is an informative model system for studying grass karyotype organization. Previous studies of a limited number of species and reference chromosomes have not provided a comprehensive picture of the enigmatic phylogenetic relationships in the genus. Comparative chromosome barcoding, which enables the reconstruction of the evolutionary history of individual chromosomes and their segments, allowed us to infer the relationships between putative ancestral karyotypes of extinct species and extant karyotypes of current species. We used over 80 chromosome-specific BAC (bacterial artificial chromosome) clones derived from five reference chromosomes of B. distachyon as probes against the karyotypes of twelve accessions representing five diploid and polyploid Brachypodium perennials. The results showed that descending dysploidy is common in Brachypodium and occurs primarily via nested chromosome fusions. Brachypodium distachyon was rejected as a putative ancestor for allotetraploid perennials and B. stacei for B. mexicanum. We propose two alternative models of perennial polyploid evolution involving either the incorporation of a putative x = 5 ancestral karyotype with di erent descending dysploidy patterns compared to B. distachyon chromosomes or hybridization of two x = 9 ancestors followed by genome doubling and descending dysploidy. Details of the karyotype structure and evolution in several Brachypodium perennials are revealed for the first time

First insights into the genetic diversity of Mycobacterium tuberculosis isolates from HIV-infected Mexican patients and mutations causing multidrug resistance

<p>Abstract</p> <p>Background</p> <p>The prevalence of infections with <it>Mycobacterium tuberculosis </it>(MTb) and nontuberculous mycobacteria (NTM) species in HIV-infected patients in Mexico is unknown. The aims of this study were to determine the frequency of MTb and NTM species in HIV-infected patients from Mexico City, to evaluate the genotypic diversity of the <it>Mycobacterium tuberculosis </it>complex strains, to determine their drug resistance profiles by colorimetric microplate Alamar Blue assay (MABA), and finally, to detect mutations present in <it>kat</it>G, <it>rpo</it>B and <it>inh</it>A genes, resulting in isoniazid (INH) and rifampin (RIF) resistance.</p> <p>Results</p> <p>Of the 67 mycobacterial strains isolated, 48 were identified as MTb, 9 as <it>M. bovis</it>, 9 as <it>M. avium </it>and 1 as <it>M. intracellulare</it>. IS<it>6110</it>-RFLP of 48 MTb strains showed 27 profiles. Spoligotyping of the 48 MTb strains yielded 21 patterns, and 9 <it>M. bovis </it>strains produced 7 patterns. Eleven new spoligotypes patterns were found. A total of 40 patterns were produced from the 48 MTb strains when MIRU-VNTR was performed. Nineteen (39.6%) MTb strains were resistant to one or more drugs. One (2.1%) multidrug-resistant (MDR) strain was identified. A novel mutation was identified in a RIF-resistant strain, GAG → TCG (Glu → Ser) at codon 469 of <it>rpo</it>B gene.</p> <p>Conclusions</p> <p>This is the first molecular analysis of mycobacteria isolated from HIV-infected patients in Mexico, which describe the prevalence of different mycobacterial species in this population. A high genetic diversity of MTb strains was identified. New spoligotypes and MIRU-VNTR patterns as well as a novel mutation associated to RIF-resistance were found. This information will facilitate the tracking of different mycobacterial species in HIV-infected individuals, and monitoring the spread of these microorganisms, leading to more appropriate measures for tuberculosis control.</p

Surveillance and diagnostics of the emergent Sri Lankan cassava mosaic virus (Fam. Geminiviridae) in Southeast Asia

Emergent agricultural pathogens cause severe damage worldwide and their invasive potential is significantly increased by global trade, crop intensification and climate change. Standard surveillance and diagnostic protocols need to be evaluated and implemented, particularly with diseases caused by a wide range of pathogens that induce similar symptoms. Such is the case with Cassava Mosaic Disease (CMD) present in Africa and Asia, and associated with mixed virus infections and recombinant and re-assorted virus strains. CMD has been recently reported in Southeast Asia (SEA) and is already widely spread throughout this region. This communication offers an update on protocols and tools used to track the distribution of CMD and to characterize the pathogen associated with it in SEA

Draft Genome Sequence of Fusarium oxysporum f. sp. cubense Tropical Race 4 from Peru, obtained by nanopore and illumina hybrid assembly

Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) is the causal agent of Fusarium wilt, a major threat to the banana industry worldwide. Here, we report the genome of a Foc TR4 strain from Peru, sequenced using a combination of Illumina and Oxford Nanopore Technologies

Mitochondrial genetic diversity of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) associated with cassava in Lao PDR

Cassava Mosaic Disease (CMD) caused by Sri Lankan cassava mosaic virus (SLCMV), has rapidly spread in Southeast Asia (SEA) since 2016. Recently it has been documented in Lao PDR. Previous reports have identified whitefly species of B. tabaci as potential vectors of CMD in SEA, but their occurrence and distribution in cassava fields is not well known. We conducted a countrywide survey in Lao PDR for adult whiteflies in cassava fields, and determined the abundance and genetic diversity of the B. tabaci species complex using mitochondrial cytochrome oxidase I (mtCOI) sequencing. In order to expedite the process, PCR amplifications were performed directly on whitefly adults without DNA extraction, and mtCOI sequences obtained using nanopore portable-sequencing technology. Low whitefly abundances and two cryptic species of the B. tabaci complex, Asia II 1 and Asia II 6, were identified. This is the first work on abundance and genetic identification of whiteflies associated with cassava in Lao PDR. This study indicates currently only a secondary role for Asia II in spreading CMD or as a pest. Routine monitoring and transmission studies on Asia II 6 should be carried out to establish its potential role as a vector of SLCMV in this region

Electrochemical degradation of surfactants in domestic wastewater using a DiaClean® cell equipped with a boron-doped diamond electrode

Treating domestic wastewater has become more and more complicated due to the high content of different types of detergents. In this context, advanced electro-oxidation (AEO) has become a powerful tool for complex wastewater remediation. The electrochemical degradation of surfactants present in domestic wastewater was carried out using a DiaClean® cell in a recirculation system equipped with boron-doped diamond (BDD) as the anode and stainless steel as the cathode. The effect of recirculation flow (1.5, 4.0 and 7.0 L min−1) and the applied current density (j = 7, 14, 20, 30, 40, and 50 mA cm−2) was studied. The degradation was followed by the concentration of surfactants, chemical oxygen demand (COD), and turbidity. pH value, conductivity, temperature, sulfates, nitrates, phosphates, and chlorides were also evaluated. Toxicity assays were studied through evaluating Chlorella sp. performance at 0, 3, and 7 h of treatment. Finally, the mineralization was followed by total organic carbon (TOC) under optimal operating conditions. The results showed that applying j = 14 mA cm−2 and a flow rate of 1.5 L min−1 during 7 h of electrolysis were the best conditions for the efficient mineralization of wastewater, achieving the removal of 64.7% of surfactants, 48.7% of COD, 24.9% of turbidity, and 44.9% of mineralization analyzed by the removal of TOC. The toxicity assays showed that Chlorella microalgae were unable to grow in AEO-treated wastewater (cellular density: 0 × 104 cells ml−1 after 3- and 7-h treatments). Finally, the energy consumption was analyzed, and the operating cost of 1.40 USD m−3 was calculated. Therefore, this technology allows for the degradation of complex and stable molecules such as surfactants in real and complex wastewater, if toxicity is not taken into account