Historical origins and zoonotic potential of avian influenza virus H9N2 in Tunisia revealed by Bayesian analysis and molecular characterization.

During 2009-2012, several outbreaks of avian influenza virus H9N2 were reported in Tunisian poultry. The circulating strains carried in their hemagglutinins the human-like marker 226L, which is known to be important for avian-to-human viral transmission. To investigate the origins and zoonotic potential of the Tunisian H9N2 viruses, five new isolates were identified during 2012-2016 and their whole genomes were sequenced. Bayesian-based phylogeny showed that the HA, NA, M and NP segments belong to the G1-like lineage. The PB1, PB2, PA and NS segments appeared to have undergone multiple intersubtype reassortments and to be only distantly related to all of the Eurasian lineages (G1-like, Y280-like and Korean-like). The spatiotemporal dynamic of virus spread revealed that the H9N2 virus was transferred to Tunisia from the UAE through Asian and European pathways. As indicated by Bayesian analysis of host traits, ducks and terrestrial birds played an important role in virus transmission to Tunisia. The subtype phylodynamics showed that the history of the PB1 and PB2 segments was marked by intersubtype reassortments with H4N6, H10N4 and H2N2 subtypes. Most of these transitions between locations, hosts and subtypes were statistically supported (BF > 3) and not influenced by sampling bias. Evidence of genetic evolution was observed in the predicted amino acid sequences of the viral proteins of recent Tunisian H9N2 viruses, which were characterized by the acquisition of new mutations involved in virus adaptation to avian and mammalian hosts and amantadine resistance. This study is the first comprehensive analysis of the evolutionary history of Tunisian H9N2 viruses and highlights the zoonotic risk associated with their circulation in poultry, indicating the need for continuous surveillance of their molecular evolution.

Association of common IL-10 promoter gene variants with the susceptibility to head and neck cancer in Tunisia

Background/aim: We investigated the association of three IL-10 promoter single-nucleotide polymorphisms and altered IL-10 plasma levels with the risk of head and neck cancer (HNC). Materials and methods: Study subjects comprised 194 HNC patients [137 nasopharyngeal cancer (NPC) and 57 laryngeal cancer (LC)], and 263 healthy controls. Genotyping of rs1800896 (-1082A>G), rs1800871 (-819C>T), and rs1800872 (-592A>C) IL-10 variants was performed by real-time PCR; IL-10 levels were measured by enzyme amplified immuno sensitivity assay (EAISA). Results: Study subjects comprised 194 HNC patients [137 nasopharyngeal cancer (NPC) and 57 laryngeal cancer (LC)], and 263 healthy controls. Genotyping of rs1800896 (-1082A>G), rs1800871 (-819C>T), and rs1800872 (-592A>C) IL-10 variants was performed by real-time PCR; IL-10 levels were measured by enzyme amplified immuno sensitivity assay (EAISA). Conclusion: Our results demonstrate that IL-10-1082, IL-10-819, and IL-10-592 variants, and haplotypes GC and GT constitute biomarkers for early detection of HNC, especially NPC subtype. IL-10 -819T/C and TA haplotype may be used as biomarkers for early detection of LC.

Developing reproducible bioinformatics analysis workflows for heterogeneous computing environments to support African genomics.

BACKGROUND: The Pan-African bioinformatics network, H3ABioNet, comprises 27 research institutions in 17 African countries. H3ABioNet is part of the Human Health and Heredity in Africa program (H3Africa), an African-led research consortium funded by the US National Institutes of Health and the UK Wellcome Trust, aimed at using genomics to study and improve the health of Africans. A key role of H3ABioNet is to support H3Africa projects by building bioinformatics infrastructure such as portable and reproducible bioinformatics workflows for use on heterogeneous African computing environments. Processing and analysis of genomic data is an example of a big data application requiring complex interdependent data analysis workflows. Such bioinformatics workflows take the primary and secondary input data through several computationally-intensive processing steps using different software packages, where some of the outputs form inputs for other steps. Implementing scalable, reproducible, portable and easy-to-use workflows is particularly challenging. RESULTS: H3ABioNet has built four workflows to support (1) the calling of variants from high-throughput sequencing data; (2) the analysis of microbial populations from 16S rDNA sequence data; (3) genotyping and genome-wide association studies; and (4) single nucleotide polymorphism imputation. A week-long hackathon was organized in August 2016 with participants from six African bioinformatics groups, and US and European collaborators. Two of the workflows are built using the Common Workflow Language framework (CWL) and two using Nextflow. All the workflows are containerized for improved portability and reproducibility using Docker, and are publicly available for use by members of the H3Africa consortium and the international research community. CONCLUSION: The H3ABioNet workflows have been implemented in view of offering ease of use for the end user and high levels of reproducibility and portability, all while following modern state of the art bioinformatics data processing protocols. The H3ABioNet workflows will service the H3Africa consortium projects and are currently in use. All four workflows are also publicly available for research scientists worldwide to use and adapt for their respective needs. The H3ABioNet workflows will help develop bioinformatics capacity and assist genomics research within Africa and serve to increase the scientific output of H3Africa and its Pan-African Bioinformatics Network.

Detection of generic differential RNA processing events from RNA-seq data.

RNA-seq data analysis has revealed abundant alternative splicing in eukaryotic mRNAs. However, splicing is only one of many processing events that transcripts may undergo during their lifetime. We present here RNAprof (RNA profile analysis), a program for the detection of differential processing events from the comparison of RNA-seq experiments. RNAprof implements a specific gene-level normalization procedure and compares RNA-seq coverage profiles at nucleotide resolution to detect regions of significant coverage differences, independently of splice sites or other gene features. We used RNAprof to analyze the effect of alternative-splicing regulators NSRa and NSRb on the Arabidopsis thaliana transcriptome. A number of intron retention events and alternative transcript structures were specifically detected by RNAprof and confirmed by qRT-PCR. Further tests using a public Mus musculus RNA-seq dataset and comparisons with other RNA isoform predictors showed that RNAprof uniquely identified sets of highly significant processing events as well as other relevant library-specific differences in RNA-seq profiles. This highlights an important layer of variation that remains undetected by current protocols for RNA-seq analysis.

Recombination Events Among SARS-CoV-2 Omicron Subvariants: Impact on Spike Interaction With ACE2 Receptor and Neutralizing Antibodies.

The recombination plays a key role in promoting evolution of RNA viruses and emergence of potentially epidemic variants. Some studies investigated the recombination occurrence among SARS-CoV-2, without exploring its impact on virus-host interaction. In the aim to investigate the burden of recombination in terms of frequency and distribution, the occurrence of recombination was first explored in 44 230 Omicron sequences among BQ subvariants and the under investigation "ML" (Multiple Lineages) denoted sequences, using 3seq software. Second, the recombination impact on interaction between the Spike protein and ACE2 receptor as well as neutralizing antibodies (nAbs), was analyzed using docking tools. Recombination was detected in 56.91% and 82.20% of BQ and ML strains, respectively. It took place mainly in spike and ORF1a genes. For BQ recombinant strains, the docking analysis showed that the spike interacted strongly with ACE2 and weakly with nAbs. The mutations S373P, S375F and T376A constitute a residue network that enhances the RBD interaction with ACE2. Thirteen mutations in RBD (S373P, S375F, T376A, D405N, R408S, K417N, N440K, S477N, P494S, Q498R, N501Y, and Y505H) and NTD (Y240H) seem to be implicated in immune evasion of recombinants by altering spike interaction with nAbs. In conclusion, this "in silico" study demonstrated that the recombination mechanism is frequent among Omicron BQ and ML variants. It highlights new key mutations, that potentially implicated in enhancement of spike binding to ACE2 (F376A) and escape from nAbs (RBD: F376A, D405N, R408S, N440K, S477N, P494S, and Y505H; NTD: Y240H). Our findings present considerable insights for the elaboration of effective prophylaxis and therapeutic strategies against future SARS-CoV-2 waves.

The African Human Microbiome Portal: a public web portal of curated metagenomic metadata.

There is growing evidence that comprehensive and harmonized metadata are fundamental for effective public data reusability. However, it is often challenging to extract accurate metadata from public repositories. Of particular concern is the metagenomic data related to African individuals, which often omit important information about the particular features of these populations. As part of a collaborative consortium, H3ABioNet, we created a web portal, namely the African Human Microbiome Portal (AHMP), exclusively dedicated to metadata related to African human microbiome samples. Metadata were collected from various public repositories prior to cleaning, curation and harmonization according to a pre-established guideline and using ontology terms. These metadata sets can be accessed at https://microbiome.h3abionet.org/. This web portal is open access and offers an interactive visualization of 14 889 records from 70 bioprojects associated with 72 peer reviewed research articles. It also offers the ability to download harmonized metadata according to the user's applied filters. The AHMP thereby supports metadata search and retrieve operations, facilitating, thus, access to relevant studies linked to the African Human microbiome. Database URL:  https://microbiome.h3abionet.org/.

A Longitudinal Study in Tunisia to Assess the Anti-RBD IgG and IgA Responses Induced by Three Different COVID-19 Vaccine Platforms.

BACKGROUND: Vaccination constitutes the best strategy against COVID-19. In Tunisia, seven vaccines standing for the three main platforms, namely RNA, viral vector, and inactivated vaccines, have been used to vaccinate the population at a large scale. This study aimed to assess, in our setting, the kinetics of vaccine-induced anti-RBD IgG and IgA antibody responses. METHODS: Using in-house developed and validated ELISA assays, we measured anti-RBD IgG and IgA serum antibodies in 186 vaccinated workers at the Institut Pasteur de Tunis over 12 months. RESULTS: We showed that RNA vaccines were the most immunogenic vaccines, as compared to alum-adjuvanted inactivated and viral-vector vaccines, either in SARS-CoV-2-naïve or in SARS-CoV-2-experienced individuals. In addition to the IgG antibodies, the vaccination elicited RBD-specific IgAs. Vaccinated individuals with prior SARS-CoV-2 infection exhibited more robust IgG and IgA antibody responses, as compared to SARS-CoV-2-naïve individuals. CONCLUSIONS: After following up for 12 months post-immunization, we concluded that the hierarchy between the platforms for anti-RBD antibody-titer dynamics was RNA vaccines, followed by viral-vector and alum-adjuvanted inactivated vaccines.

A regionally based precision medicine implementation initiative in North Africa:The PerMediNA consortium.

Precision Medicine is being increasingly used in the developed world to improve health care. While several Precision Medicine (PM) initiatives have been launched worldwide, their implementations have proven to be more challenging particularly in low- and middle-income countries. To address this issue, the "Personalized Medicine in North Africa" initiative (PerMediNA) was launched in three North African countries namely Tunisia, Algeria and Morocco. PerMediNA is coordinated by Institut Pasteur de Tunis together with the French Ministry for Europe and Foreign Affairs, with the support of Institut Pasteur in France. The project is carried out along with Institut Pasteur d'Algérie and Institut Pasteur du Maroc in collaboration with national and international leading institutions in the field of PM including Institut Gustave Roussy in Paris. PerMediNA aims to assess the readiness level of PM implementation in North Africa, to strengthen PM infrastructure, to provide workforce training, to generate genomic data on North African populations, to implement cost effective, affordable and sustainable genetic testing for cancer patients and to inform policy makers on how to translate research knowledge into health products and services. Gender equity and involvement of young scientists in this implementation process are other key goals of the PerMediNA project. In this paper, we are describing PerMediNA as the first PM implementation initiative in North Africa. Such initiatives contribute significantly in shortening existing health disparities and inequities between developed and developing countries and accelerate access to innovative treatments for global health.

Retrospective Phylodynamic and Phylogeographic Analysis of the Bluetongue Virus in Tunisia.

Bluetongue virus (BTV) is an arbovirus considered as a major threat for the global livestock economy. Since 1999, Tunisia has experienced several incursions of BTV, during which numerous cases of infection and mortality have been reported. However, the geographical origin and epidemiological characteristics of these incursions remained unclear. To understand the evolutionary history of BTV emergence in Tunisia, we extracted from Genbank the segment 6 sequences of 7 BTV strains isolated in Tunisia during the period 2000 to 2017 and blasted them to obtain a final dataset of 67 sequences. We subjected the dataset to a Bayesian phylogeography framework inferring geographical origin and serotype as phylodynamic models. Our results suggest that BTV-2 was first introduced in Tunisia in the 1960s and that since 1990s, the country has witnessed the emergence of other typical and atypical BTV serotypes notably BTV-1, BTV-3 and BTV-Y. The reported serotypes have a diverse geographical origin and have been transmitted to Tunisia from countries in the Mediterranean Basin. Interserotype reassortments have been identified among BTV-1, BTV-2 and BTV-Y. This study has provided new insights on the temporal and geographical origin of BTV in Tunisia, suggesting the contribution of animal trade and environment conditions in virus spread.