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/.

Development and validation of real-time recombinase polymerase amplification-based assays for detecting HPV16 and HPV18 DNA.

IMPORTANCE: HPV DNA screening is an effective approach for the prevention of cervical cancer. The novel real-time recombinase polymerase amplification-based HPV detection systems we developed constitute an improvement over the HPV detection methods currently used in clinical practice and should help to extend cervical cancer screening in the future, particularly in point-of-care test settings.

Gut microbiota profile and the influence of nutritional status on bacterial distribution in diabetic and healthy Tunisian subjects.

Gut microbiota plays a key role in the regulation of metabolism and immunity. We investigated the profile of gut microbiota and the impact of dietary intake on gut bacterial distribution in diabetic and healthy Tunisian subjects, aiming to identify a dysbiotic condition, hence opening the way to restore eubiosis and facilitate return to health. In the present research, we enrolled 10 type 1 diabetic (T1D), 10 type 2 diabetic (T2D) patients and 13 healthy (H) subjects. Illumina Miseq technology was used to sequence V3-V4 hypervariable regions of bacterial 16SrRNA gene. Data were analyzed referring to QIIME 2 pipeline. RStudio software was used to explore the role of nutrition in gut bacterial distribution. At the phylum level, we identified an imbalanced gut microbiota composition in diabetic patients marked by a decrease in the proportion of Firmicutes and an increase in the abundance of Bacteroidetes compared with H subjects. We observed higher amounts of Fusobacteria and a decline in the levels of TM7 phyla in T1D patients compared with H subjects. However, we revealed a decrease in the proportions of Verrucomicrobia in T2D patients compared with H subjects. At the genus level, T2D subjects were more affected by gut microbiota alteration, showing a reduction in the relative abundance of Faecalibacterium, Akkermansia, Clostridium, Blautia and Oscillibacter, whereas T1D group shows a decrease in the proportion of Blautia. The gut bacteria distribution was mainly affected by fats and carbohydrates consumption. Gut microbiota composition was altered in Tunisian diabetic patients and affected by dietary habits.

The first exome wide association study in Tunisia: identification of candidate loci and pathways with biological relevance for type 2 diabetes.

Introduction: Type 2 diabetes (T2D) is a multifactorial disease involving genetic and environmental components. Several genome-wide association studies (GWAS) have been conducted to decipher potential genetic aberrations promoting the onset of this metabolic disorder. These GWAS have identified over 400 associated variants, mostly in the intronic or intergenic regions. Recently, a growing number of exome genotyping or exome sequencing experiments have identified coding variants associated with T2D. Such studies were mainly conducted in European populations, and the few candidate-gene replication studies in North African populations revealed inconsistent results. In the present study, we aimed to discover the coding genetic etiology of T2D in the Tunisian population. Methods: We carried out a pilot Exome Wide Association Study (EWAS) on 50 Tunisian individuals. Single variant analysis was performed as implemented in PLINK on potentially deleterious coding variants. Subsequently, we applied gene-based and gene-set analyses using MAGMA software to identify genes and pathways associated with T2D. Potential signals were further replicated in an existing large in-silico dataset, involving up to 177116 European individuals. Results: Our analysis revealed, for the first time, promising associations between T2D and variations in MYORG gene, implicated in the skeletal muscle fiber development. Gene-set analysis identified two candidate pathways having nominal associations with T2D in our study samples, namely the positive regulation of neuron apoptotic process and the regulation of mucus secretion. These two pathways are implicated in the neurogenerative alterations and in the inflammatory mechanisms of metabolic diseases. In addition, replication analysis revealed nominal associations of the regulation of beta-cell development and the regulation of peptidase activity pathways with T2D, both in the Tunisian subjects and in the European in-silico dataset. Conclusions: The present study is the first EWAS to investigate the impact of single genetic variants and their aggregate effects on T2D risk in Africa. The promising disease markers, revealed by our pilot EWAS, will promote the understanding of the T2D pathophysiology in North Africa as well as the discovery of potential treatments.

Next-generation sequencing of Tunisian Leigh syndrome patients reveals novel variations: impact for diagnosis and treatment.

Mitochondrial cytopathies, among which the Leigh syndrome (LS), are caused by variants either in the mitochondrial or the nuclear genome, affecting the oxidative phosphorylation process. The aim of the present study consisted in defining the molecular diagnosis of a group of Tunisian patients with LS. Six children, belonging to five Tunisian families, with clinical and imaging presentations suggestive of LS were recruited. Whole mitochondrial DNA and targeted next-generation sequencing of a panel of 281 nuclear genes involved in mitochondrial physiology were performed. Bioinformatic analyses were achieved in order to identify deleterious variations. A single m.10197G>A (p.Ala47Thr) variant was found in the mitochondrial MT-ND3 gene in one patient, while the others were related to autosomal homozygous variants: two c.1412delA (p.Gln471ArgfsTer42) and c.1264A>G (p.Thr422Ala) in SLC19A3, one c.454C>G (p.Pro152Ala) in SLC25A19 and one c.122G>A (p.Gly41Asp) in ETHE1. Our findings demonstrate the usefulness of genomic investigations to improve LS diagnosis in consanguineous populations and further allow for treating the patients harboring variants in SLC19A3 and SLC25A19 that contribute to thiamine transport, by thiamine and biotin supplementation. Considering the Tunisian genetic background, the newly identified variants could be screened in patients with similar clinical presentation in related populations.

H3ABioNet genomic medicine and microbiome data portals hackathon proceedings.

African genomic medicine and microbiome datasets are usually not well characterized in terms of their origin, making it difficult to find and extract data for specific African ethnic groups or even countries. The Pan-African H3Africa Bioinformatics Network (H3ABioNet) recognized the need for developing data portals for African genomic medicine and African microbiomes to address this and ran a hackathon to initiate their development. The two portals were designed and significant progress was made in their development during the hackathon. All the participants worked in a very synergistic and collaborative atmosphere in order to achieve the hackathon's goals. The participants were divided into content and technical teams and worked over a period of 6 days. In response to one of the survey questions of what the participants liked the most during the hackathon, 55% of the hackathon participants highlighted the familial and friendly atmosphere, the team work and the diversity of team members and their expertise. This paper describes the preparations for the portals hackathon and the interaction between the participants and reflects upon the lessons learned about its impact on successfully developing the two data portals as well as building scientific expertise of younger African researchers. Database URL: The code for developing the two portals was made publicly available in GitHub repositories: [https://github.com/codemeleon/Database; https://github.com/codemeleon/AfricanMicrobiomePortal].

Association of rs662799 variant and APOA5 gene haplotypes with metabolic syndrome and its components: a meta-analysis in North Africa.

Apolipoprotein A5 (APOA5) has been linked to metabolic syndrome (MetS) in several populations. In North Africa, only the Tunisian and Moroccan populations were investigated. Our aim is to assess the association between APOA5 gene variant (rs662799) and haplotypes with MetS in Tunisian population and to perform a meta-analysis in North Africa. A total of 594 Tunisian participants were genotyped for polymorphism rs662799 using KASPar technology. Two polymorphisms rs3135506 and rs651821 in APOA5 gene genotyped in our previous study, were used in addition to rs662799 to assess the haplotype association with MetS. The genotype of 875 participants was used for the meta-analysis. Statistical analyses were performed with R software. The rs662799 increases the risk of MetS under the dominant (P=0.018) and the additive models (P=0.028) in the Tunisian population. After stratification of the cohort following the sex and the geographic origin, a positive association of rs662799 with MetS was found for participant from the Northern region and for the women group. Only the haplotype AGT showed a significant association with MetS by decreasing the risk of the disease. The meta-analysis reported a significant association of rs662799 and rs3135506 with MetS. Our results showed a significant association between the APOA5 gene variants rs662799 and haplotypes with MetS and its traits in Tunisia. An impact of the sex and the geographic origin on the genotype distribution was highlighted. Our funding emphasizes the role of APOA5 in the development of MetS in North Africa.

Gut microbiota imbalances in Tunisian participants with type 1 and type 2 diabetes mellitus.

Gut microbiota plays an important role in the regulation of the immune system and host's metabolism. We aimed to characterize the gut microbiota of Tunisian participants with and without diabetes.We enrolled ten participants with type 1 diabetes mellitus (T1DM), ten patients with type 2 diabetes mellitus (T2DM), and 11 subjects without diabetes. Bacteria was quantified in fecal samples by quantitative PCR (qPCR). Statistical tests and multivariate analysis were performed using RStudio program.Results showed that the proportions of Firmicutes, Akkermansia muciniphila, and Faecalibacterium prausnitzii (P≤0.041), as well as, the ratio Firmicutes/Bacteroidetes decreased in participants with T1DM compared with those without diabetes (p = 0.036). Participants with T2DM presented a reduction in the amounts of A. muciniphila and F. prausnitzii compared with those without diabetes (P≤0.036). Furthermore, A. muciniphila is negatively correlated with glucose level (P=0.022) and glycated hemoglobin (HbA1c) (P=0.035). Multivariate analysis revealed that participants with diabetes formed a cluster apart compared with those without diabetes.In conclusion the gut bacteria of Tunisian participants with diabetes was altered. The gut bacterial profile, especially the distribution of A muciniphila in participants with diabetes was affected by glycemic dysregulation. The investigation of the gut microbiota may help clinicians to improve diagnosis and treatment of diabetes and its complications.