Biology subjects

Zeghbib, S.

Publications and source records attributed to Zeghbib, S..

7 recordsLinked to original sources

bioRxiv2026

Intraspecific morphological variability of the invasive mosquito Aedes koreicus in Europe: genetic characterisation and population-level insights

BackgroundThe invasive mosquito Aedes koreicus has established populations in several European countries during the past decade, raising increasing public health concerns due to its potential role as a vector of pathogens. While species identification is primarily based on morphological characters, Ae. koreicus exhibits distinct morphological variants originating from mainland Korea and Jeju Island, which complicates surveillance and may lead to misidentification, particularly in regions where closely related species co-occur. To date, the genetic basis and population-level relevance of these morphological forms in Europe remain poorly understood. MethodsWe investigated the co-occurrence of two morphological forms of Ae. koreicus in Hungary, representing the first confirmed European location where both forms were detected sympatrically and even within the same breeding sites. Adult mosquitoes were morphologically characterised using diagnostic traits, and individuals representing both morphotypes were subjected to comprehensive genetic analyses. We sequenced multiple mitochondrial markers (COX1, COX2, COX3, ATP6, ND1, ND3) and the nuclear ITS2 region using Oxford Nanopore long-read sequencing. Phylogenetic reconstructions and haplotype network analyses were applied to assess genetic differentiation between morphotypes and to compare them with Aedes japonicus as a closely related reference species. ResultsAcross all analysed mitochondrial and nuclear markers, no genetic differentiation was detected between specimens identified as the "mainland" or "Jeju-do" morphological forms of Ae. koreicus. Phylogenetic and haplotype network analyses consistently grouped individuals independently of their morphotype, indicating a shared genetic background at the population level. In contrast, Ae. japonicus formed a clearly distinct genetic lineage, confirming the robustness of the applied markers for interspecific discrimination. ConclusionsOur results demonstrate that the observed morphological variability in Ae. koreicus populations are not underpinned by detectable genetic differentiation using commonly applied mitochondrial and genomic markers. These findings highlight the limitations of using morphology alone to infer population origin or structure and emphasise the need for heightened awareness of intraspecific variability in routine surveillance. Accurate morphological identification remains critical, particularly in citizen science-based monitoring programmes and AI-based automatization platforms, such as Mosquito Alert, to avoid confusion with morphologically similar invasive species. Further studies integrating genomic and ecological approaches are required to elucidate the mechanisms underlying morphological variability in this emerging vector species.

zoology↗

bioRxiv2025

Tracing SARS-CoV-2 Evolution in Algeria: Insights from 2020-2023

SARS-CoV-2 continues to circulate globally, leading to the emergence of new viral sublineages. This study examined 449 full-length genomic sequences from Algeria (March 2020 to May 2023) to explore SARS-CoV-2 evolution in this region. Our analysis revealed multiple introductions of viral strains, which were marked by significant genomic changes over time. Algeria-specific mutations were identified, providing insights into regional adaptations and evolutionary dynamics. Furthermore, a statistically significant recombination event was detected using the RDP 5 software. EPI_ISL_15920753 was recombinant, whereas EPI_ISL_15790700 and EPI_ISL_12156732 constituted the major and minor parents, respectively. Notably, haplotype analysis revealed 179 distinct haplotypes, including a highly connected node (H91) associated with a superspreading event later in the pandemic (July-September 2022), suggesting rapid transmission likely driven by mobile individuals and large gatherings. These findings emphasize the ongoing evolution of SARS-CoV-2 in local settings and highlight the importance of genomic surveillance for tracking emerging mutations and their potential impact. ImportanceBridging a critical gap in North African genomic surveillance, this study presents the first comprehensive evolutionary analysis of SARS-CoV-2 in Algeria using a significantly larger dataset of 449 sequences, a substantial increase from the only previous study of 29 genomes conducted at the onset of the pandemic. Our results provide essential insights into how the virus was introduced, disseminated, and adapted within the country, thereby guiding regional public health initiatives and supplying important data for global comprehension of the evolution of SARS-CoV-2.

molecular biology↗

bioRxiv2022

Isolation and genome characterization of Lloviu virus from Italian Schreibers bent-winged bats

Lloviu cuevavirus (LLOV) was the first identified member of Filoviridae family outside the Ebola and Marburgvirus genera. A massive die-off of Schreibers bent-winged bats (Miniopterus schreibersii) in the Iberian Peninsula in 2002 led to its discovery. Studies with recombinant and wild-type LLOV isolates confirmed the susceptibility of human-derived cell lines and primary human macrophages to LLOV infection in vitro. Based on these data, LLOV is now considered as a potential zoonotic virus with unknown pathogenicity to humans and bats. We examined bat samples from Italy for the presence of LLOV in an area outside of the currently known distribution range of the virus. We detected one positive sample from 2020, sequenced the complete coding sequence of the viral genome and established an infectious isolate of the virus. In addition, we performed the first comprehensive evolutionary analysis of the virus, using the Spanish, Hungarian and the Italian sequences. The most important achievement of this article is the establishment of an additional infectious LLOV isolate from a bat sample using the SuBK12-08 cells, demonstrating that this cell line is highly susceptible to LLOV infection. These results further confirms the role of these bats as the host of this virus, possibly throughout their entire geographic range. This is an important result to further understand the role of bats as the natural hosts for zoonotic filoviruses.

microbiology↗

bioRxiv2021

Aedes koreicus, a vector on the rise: pan-European genetic patterns, mitochondrial and draft genome sequencing

BackgroundThe mosquito Aedes koreicus (Edwards, 1917) is a recent invader on the European continent that was introduced to several new places since its first detection in 2008. Compared to other exotic Aedes mosquitoes with public health significance that invaded Europe during the last decades, this species biology, behavior, and dispersal patterns were poorly investigated to date. Methodology/Principal FindingsTo understand the species population relationships and dispersal patterns within Europe, a fragment of the COI gene was sequenced from 130 mosquitoes, collected from five countries where the species has been introduced and/or established. Oxford Nanopore and Illumina sequencing techniques were combined to generate the first complete nuclear and mitochondrial genomic sequences of Ae. koreicus from the European region. The complete genome of Ae. koreicus is 879 Mb. COI haplotype analyses identified five major groups (altogether 31 different haplotypes) and revealed a large-scale dispersal pattern between European Ae. koreicus populations. Continuous admixture of populations from Belgium, Italy, and Hungary was highlighted, additionally, haplotype diversity and clustering clearly indicate a separation of German sequences from other populations, pointing to an independent introduction of Ae. koreicus to Europe. Finally, a genetic expansion signal was identified, suggesting the species might be present in more locations than currently detected. Conclusions/SignificanceOur results highlight the importance of genetic research of invasive mosquitoes to understand general dispersal patterns, reveal main dispersal routes and form the baseline of future mitigation actions. The first complete genomic sequence also provides a significant leap in the general understanding of this species, opening the possibility for future genome-related studies, such as the detection of Single Nucleotide Polymorphism markers. Considering its public health importance, it is crucial to further investigate the species population genetic dynamic, including a larger sampling and additional genomic markers. Author SummaryIn the present context of globalization and changing environment, the rapid spread of Invasive Mosquito Species (IMS) across Europe represents a serious public health threat because some species are competent vectors for several pathogens. A better knowledge of the IMS population relationships, demographic trends, and dispersal patterns can help the relevant authorities mitigating further spread. Aedes koreicus is an IMS that invaded the continent and has been expanding its geographic range over the last decade. In the present study, one of the most popular DNA marker (COI) was used to investigate the pan-European haplotype diversity and phylogenetic relatedness within and between Ae. koreicus populations. Also, the first complete mitochondrial genome and draft nuclear genome of Ae. koreicus were generated using combined high-throughput sequencing techniques (Oxford Nanopore, Illumina). This provides a significant leap in the general understanding of this species and opens the possibility for future genomic studies.

genetics↗

bioRxiv2021

Reservoir host studies of Lloviu virus: first isolation, sequencing and serology in Schreiber's bats in Europe

IntroductoryFiloviruses are prime examples of emerging human pathogens that are transmitted to humans by zoonotic spillover events. Since their initial discovery, filovirus outbreaks have occured with increasing frequency and intensity. There is an urgent need to better understand their enzootic ecology and pathogenic potential, given recent zoonotic virus spillover events including the 2013-2016 West African Ebola virus (EBOV) epidemic. Several novel filoviruses have been discovered with a markedly wider geographic distribution than previously described. One of these novel filoviruses, Lloviu virus (LLOV), was first identified in 2002 in Schreibers bats (Miniopterus schreibersii) in Spain, Portugal, and southern France. Subsequently, in 2016, LLOV was detected during the passive monitoring of bats in Hungary. Here we report the first isolation of infectious Lloviu virus; from the blood of an asymptomatic Schreibers bat, subsequently cultivated in the Miniopterus sp. kidney cell line SuBK12-08. We also show that LLOV is able to infect monkey and human cells, suggesting that LLOV might have spillover potential. We performed a multi-year surveillance of LLOV and detected LLOV RNA in both deceased and asymptomatic live animals as well as in coupled ectoparasites from the families Nycteribiidae and Ixodidae. We present data on the natural infection and seropositivity of Schreibers bats and provide novel LLOV genomic sequence information from a bat host and an arthropod parasite. Our data support the role of bats, specifically Miniopterus schreibersii as natural reservoirs for the LLOV filovirus in Europe. We also suggest that bat-associated parasites might play a role in the natural ecology of filoviruses in temperate climate regions compared to filoviruses in the tropics. These results raise the possibility of cross-species transmission events via bat-human interactions.

microbiology↗

bioRxiv2020

The Anti-histamine Azelastine, Identified by Computational Drug Repurposing, Inhibits SARS-CoV-2 Infection in Reconstituted Human Nasal Tissue In Vitro

BackgroundThe COVID-19 pandemic is an enormous threat for healthcare systems and economies worldwide that urgently demands effective preventive and therapeutic strategies. Unlike the development of vaccines and new drugs specifically targeting SARS-CoV-2, repurposing of approved or clinically tested drugs can provide an immediate solution. MethodsWe applied a novel computational approach to search among approved and clinically tested drugs from the DrugBank database. Candidates were selected based on Shannon entropy homology and predefined activity profiles of three small molecules with proven anti-SARS-CoV activity and a published data set. Antiviral activity of a predicted drug, azelastine, was tested in vitro in SARS-CoV-2 infection assays with Vero E6 monkey kidney epithelial cells and reconstituted human nasal tissue. The effect on viral replication was assessed by quantification of viral genomes by droplet digital PCR. FindingsThe computational approach with four independent queries identified major drug families, most often and in overlapping fashion anti-infective, anti-inflammatory, anti-hypertensive, anti-histamine and neuroactive drugs. Azelastine, an histamine 1 receptor-blocker, was predicted in multiple screens, and based on its attractive safety profile and availability in nasal formulation, was selected for experimental testing. Azelastine significantly reduced cytopathic effect and SARS-CoV-2 infection of Vero E6 cells with an EC50 of [~]6 M both in a preventive and treatment setting. Furthermore, azelastine in a commercially available nasal spray tested at 5-fold dilution was highly potent in inhibiting viral propagation in SARS-CoV-2 infected reconstituted human nasal tissue. InterpretationsAzelastine, an anti-histamine, available in nasal sprays developed against allergic rhinitis may be considered as a topical prevention or treatment of nasal colonization with SARS-CoV-2. As such, it could be useful in reducing viral spread and prophylaxis of COVID-19. Ultimately, its potential benefit should be proven in clinical studies. Fundingprovided by the Hungarian government to the National Laboratory of Virology and by CEBINA GmbH.

microbiology↗

bioRxiv2020

Multiple SARS-CoV-2 introductions shaped the early outbreak in Central Eastern Europe: comparing Hungarian data to a worldwide sequence data-matrix

Severe Acute Respiratory Syndrome Coronavirus 2 is the third highly pathogenic human coronavirus in history. Since the emergence in Hubei province, China, during late 2019 the situation evolved to pandemic level. Following China, Europe was the second epicenter of the pandemic. To better comprehend the detailed founder mechanisms of the epidemic evolution in Central-Eastern Europe, particularly in Hungary, we determined the full-length SARS-CoV-2 genomes from 32 clinical samples collected from laboratory confirmed COVID-19 patients over the first month of disease in Hungary. We applied a haplotype network analysis on all available complete genomic sequences of SARS-CoV-2 from GISAID database as of the 21th of April, 2020. We performed additional phylogenetic and phylogeographic analyses to achieve the recognition of multiple and parallel introductory events into our region. Here we present a publicly available network imaging of the worldwide haplotype relations of SARS-CoV-2 sequences and conclude the founder mechanisms of the outbreak in Central-Eastern Europe.

microbiology↗