The Human transferrin receptor 1 (TfR1) mediates cellular iron uptake via clathrin-mediated endocytosis of transferrin (Tf) and is an important therapeutic target, particularly in anti-cancer strategies. Understanding its structural dynamics is crucial to avoid disrupting ligand-induced internalization. In this study, we constructed a complete model of the TfR1 dimer and docked two Tf structures to form the TfR1-2Tf complex. Conformational dynamics of apo TfR1 and the TfR1-2Tf complex were investigated using normal mode analysis and molecular dynamics simulations, including solvent and membrane environments. In apo TfR1, the molecular stalk and apical subdomain were highly flexible, whereas the helical and protease-like subdomains displayed moderate mobility. Tf binding stabilizes the stalk and upper helical subdomain, limiting large tilting motions, while preserving hinge regions necessary for conformational changes. Dynamic cross-correlation analysis showed that Tf binding also enhances coordination between subdomains. Novel interface residues mediating interactions between the Tf N-lobes and the TfR1 stalk were identified. These findings provide a valuable structural basis for rational ligand design targeting TfR1 without disrupting its functional dynamics, offering insights for improved drug delivery and receptor inhibition strategies.

Hospital wastewater represents a critical hotspot for the dissemination of antibiotic resistance genes (ARGs), serving both as an environmental reservoir and a transmission pathway for multidrug-resistant bacteria into receiving ecosystems. The intense antibiotic selective pressure within healthcare facilities promotes the emergence, persistence and amplification of resistant strains, posing substantial risks to public health and environmental integrity. This study aimed to characterize Escherichia coli (E. coli) isolates recovered from hospital wastewater effluents in multiple cities across Gabon, with emphasis on bacterial loads, antimicrobial resistance patterns and associated genetic determinants. Wastewater samples were aseptically collected from sewer outlets of eleven healthcare facilities distributed across five provinces over a 12-week period, structured into two six-week sampling campaigns to capture temporal variability. A total of 158 bacterial isolates were obtained, among which 49 were confirmed as E. coli. Mean concentrations of presumptive E. coli ranged from 7.1 × 10³ to 1.49 × 10⁹ CFU/mL, indicating substantial microbial contamination of hospital effluents. Antimicrobial susceptibility testing using the Kirby–Bauer disk diffusion method against 19 antibiotics revealed that all isolates exhibited multidrug-resistant phenotypes. Resistance rates were particularly high to β-lactams and third-generation cephalosporins, reaching 90–100% in most facilities, reflecting strong selective pressure and widespread circulation of resistance mechanisms in urban aquatic environments. In contrast, carbapenems and amikacin remained comparatively effective, with resistance levels below 40%, suggesting partial preservation of last-resort therapeutic options. The values of the Multiple Antibiotic Resistance Index (MARI) ranged from 0.21 to 0.84, indicating selection pressure on different classes of antibiotics. Phylogenetic analysis showed a predominance of phylogroup A, traditionally considered commensal but increasingly associated with the spread of resistance. Groups B2, D/E and F proved to be the most resistant. These groups showed marked resistance to first-line antibiotics. The blaCTX-M-1 was the most prevalent resistance determinant (66.6%), occurring twice as frequently as blaSHV (33.3%), a finding that confirms the significant circulation of extended-spectrum β-lactamase-producing E. coli. Overall, these findings highlight hospital wastewater as a major reservoir and dissemination source of multidrug-resistant E. coli, underscoring the urgent need for improved wastewater treatment, strengthened antimicrobial stewardship and integrated One Health-based surveillance strategies.

Orthohepanaviruses are viruses that infect a number of mammals, including humans and non-human primates. However, previous studies in great apes in Gabon in 2001 found one strain of hepadnavirus (HBV ChBassi strain) displaying genetic recombination between human, gorilla and chimpanzee strains, suggesting cross-species transmissions among primates. The aim of this study was to evaluate the presence of HBV DNA in non-human primates (NHPs) and to compare it with human HBV strains in order to assess the zoonotic potential. We analyzed feces from 1891 NHPs, collected in forests in Gabon, to find human HBV-related hepadnaviruses by amplifying a portion of the S gene using hemi-nested techniques, followed by sequencing. A total of 51 samples were PCR-positive. Thirteen of the fourteen sequences obtained after sequencing were phylogenetically more closely related to chimpanzee HBV strains, while the fourteenth sequence was associated with the ChBassi HBV strain. This study shows that HBV infection is endemic in wild-born great apes in Gabon. The detection of a strain genetically close to the Bassi strain (a potential zoonotic strain) highlights the need for more in-depth studies to provide an effective response as part of the ‘One Health’ initiative.

Significant advancements in, and increased access to, antiretroviral therapy (ART) have substantially reduced the risk of mother-to-child transmission (MTCT) of HIV. However, antiretroviral drug resistance (HIVDR) is a serious challenge affecting both adults and children. Because of high HIV prevalence and genetic diversity, Central Africa is considered the epicenter of the epidemic. Yet information on drug resistance profiles and clinical efficacy of newer antiretroviral agents among children is limited compared to adult cohorts. Not to mention that several countries of the subregion, including Gabon, Chad, and São Tomé and Príncipe, lack updated epidemiological data. This article aims to provide an overview of HIV prevention of mother-to-child transmission (PMTCT), focusing on four key elements: prevalence rates; associated risk factors; molecular characterization of pediatric HIV; and virological response to antiretroviral therapy in Central Africa. We have gathered studies published between 2014 and 2026 across PubMed and Research Gate databases and AJOL. The synthesized data reveal high genetic variability of HIV and a dominant CRF02AG variant within the considered populations. The results of this study indicate a range of virological failure rates in the pediatric population on ART for at least six months, ranging from 11.1% to 89.1%. These rates are attributed to a high frequency of resistance-associated mutations (RAMs) and suboptimal adherence to antiretroviral treatment. The main determinants of non-adherence are social stigma, geographic barriers (distance from specialized care centers) and orphan status. Strengthened virological and molecular surveillance programs must be implemented in Central Africa to ensure optimal care for pregnant women, children, and adolescents. Addressing these gaps is imperative in order to bridge the gap between the current epidemiological profile and the WHO’s goals for the elimination of pediatric HIV.

Background/Objectives: Antimicrobial resistance (AMR) is a global threat to human, animal, and environmental health. Among bacteria, E. coli is frequently used as a key indicator of AMR. Despite their genetic proximity to humans, studies on AMR in Non-Human Primates (NHPs) remain limited, particularly in semi-anthropized environments. This study aims to characterize the antibiotic resistance profiles and phylo-groups of E. coli isolated from NHPs and humans at a primatology center. Methods: A total of 143 stool samples were collected, including 125 from NHPs and 18 from humans. Isolates were cultured on Eosin Methylene Blue agar and then identified by MALDI-TOF mass spectrometry. Antibiotic susceptibility was assessed using the Kirby–Bauer disk diffusion method, with 30 antibiotics following CASFM-EUCAST recommendations. E. coli phylo-groups were characterized by quadruplex PCR according to the Clermont method, targeting the genes. Results: A total of 122 E. coli isolates (85.31%) were recovered, with comparable prevalence observed across NHPs and human staff. More than half of the isolates (55.74%) were resistant to at least one antibiotic tested, and 12.3% were classified as multi-drug resistant (MDR). Resistance rates of isolates in Mandrillus sphinx, Pan troglodytes, and humans were 50.6%, 57.7%, and 80.0%, respectively, with no significant statistical difference (p = 0.11). A single Extended-Spectrum Beta-Lactamase (ESBL) producing isolate was identified in the mandrill. Phylo-group analysis revealed the dominance of group A (50%), followed by groups B1, D, and C. Conclusions: Resistance profiles and phylo-group distribution among NHPs could suggest bacterial exchange and potential for cross-transmission of AMR within the shared environment.

SARS-CoV-2, the causative agent of COVID-19, emerged in late 2019 and rapidly developed into a global health crisis. In this study, we analysed 173,194 SARS-CoV-2 genomes from the GISAID database to explore the intra-continental dynamics and distribution of variants across Africa between 2020 and 2024. We have identified 1377 distinct lineages, which were classified by clade to assess associations with infection and mortality rate. So, we conducted a Shannon entropy analysis to confirm the diversity and we applied a Correspondence Analysis (CA). Our findings revealed that one of the deadliest in Africa during the Delta wave, lineage AY.45 predominated in the South Africa cluster, whereas AY.34.1 drove transmission in the Atlantic West Africa cluster, underscoring regional heterogeneity. Furthermore, early in the pandemic, men exhibited a 39% higher risk of infection compared to women (aOR: 1.39, 95% CI [1.34–1.45]), particularly in association with clade G. By contrast, later stages were dominated by clade GRA, which disproportionately affected the elderly (≥70 years; aOR: 1.39, 95% CI [1.33–1.45]) and children (0–9 years; aOR: 1.26, 95% CI [1.20–1.33]). Our analysis highlighted that the pandemic on the African continent unfolded as a mosaic of epidemics shaped by diverse variants and regional epidemiological contexts. These findings emphasize the importance of genomic surveillance to capture local epidemic signatures and inform region-specific public health strategies.