Biology subjects

Guellil, M.

Publications and source records attributed to Guellil, M..

6 recordsLinked to original sources

bioRxiv2026

Co-occurrence of Yersinia pestis and other zoonoses during European prehistory

The infection of humans by the causal agent of Plague, Yersinia pestis, has been attested as far back as 5,500 BP. Although the specific patho-mechanism and ultimate origin of the disease caused by these prehistoric genomes remains unclear, the bacterium spread through Europe, likely during the Late Neolithic to Bronze Age (LNBA). In this study, we analysed 9 genomic samples originating from 8 different human individuals dating to around 4950 cal BP from the site of Grotta della Spinosa, Tuscany, Italy. Metagenomic screening of these samples reveals one individual (GSP013) to be co-infected by Yersinia pestis, Erysipelothrix rhusiopathiae, and Hepatitis B virus (HBV). At least three further individuals from the site were infected with HBV, indicating its wider presence within the community. The phylogenetic placement of Y. pestis in GSP013 shows that this strain is closely related to the earliest LNBA Caucasus genomes of the bacterium, basal to later European diversity. This represents the earliest evidence of Y. pestis in the Italian peninsula (and Southern Europe more widely) to date, predating previously discovered genomes by at least 200 years. Furthermore, we retrieved 60 newly reported ancient genomes of Erysipelothrix rhusiopathiae and Erysipelothrix tonsillarum from animals and humans, dating back from 8,300 BP to 100 BP. Of these new genomes, 15 of which stem from individuals known to be infected by Y. pestis. This contributes to our understanding of Y. pestis transmission in prehistoric Europe and possible reservoirs, and offers insights into disease dynamics in communities during the 3rd millennium BCE.

evolutionary biology↗

bioRxiv2024

2500 Years of Human Betaherpesvirus 6A and 6B Evolution Revealed by Ancient DNA

Human betaherpesviruses 6A and 6B are double-stranded DNA viruses, specialised in infecting humans and are best known as the main causative pathogens of the common childhood infection "sixth disease". Despite only being discovered in the 1980s, these viruses are speculated to have a much longer and more complex history within the human population than available modern data make clear. The viruses are carried by large fractions of the human population and can integrate into the human genome, leading to a wide range of clinical manifestations of varied severity. Here, we present the first nine full and two partial ancient genomes of HHV-6A and 6B, dating as far back as the Italian Iron Age (ca. 1100-600 BCE). We demonstrate that large fractions of the current HHV-6 diversity were already well established in the human population by the 14th century CE. Our data suggests that HHV-6B integrated into the human genome at the latest before the 1st-6th century CE, with two integrated clades being populated by ancient DNA genomes in our phylogeny, which further supports that they originated from likely much older ancient founder events. Additionally, we show that all known inherited chromosomally integrated (ici-)HHV-6A clades were already represented in European historical populations, confirming that ici-HHV-6A no longer integrates into the human germline within populations of European ancestry and likely endogenized in early human history. Finally, our results demonstrate the unique suitability of archaeological remains and ancient DNA for the study of the evolution of integrated viruses in human populations.

evolutionary biology↗

bioRxiv2024

Screening great ape museum specimens for DNA viruses

Natural history museum collections harbour a record of wild species from the past centuries, providing a unique opportunity to study animals as well as their infectious agents. Thousands of great ape specimens are kept in these collections, and could become an important resource for studying the evolution of DNA viruses. Their genetic material is likely to be preserved in dry museum specimens, as reported previously for monkeypox virus genomes from historical orangutan specimens. Here, we screened 209 great ape museum specimens for 99 different DNA viruses, using hybridization capture coupled with short-read high-throughput sequencing. We determined the presence of multiple viruses within this dataset from historical specimens and obtained several near-complete viral genomes. In particular, we report high-coverage (>18-fold) hepatitis B virus genomes from one gorilla and two chimpanzee individuals, which are phylogenetically placed within clades infecting the respective host species.

genomics↗

bioRxiv2024

A complete mitochondrial genome of a Roman-era Plasmodium falciparum

Malaria has historically been one of the leading infection-related causes of death in human populations. To this day, it continues to pose a significant public health threat in African countries, particularly among children. Humans are affected by five Plasmodium species, with Plasmodium falciparum being the most lethal. The study of pathogenic DNA from ancient human remains has been vital in understanding the origin, evolution, and virulence of human-infecting pathogens. However, there have been no complete pre-20th century mitochondrial DNA (mtDNA) or genomic sequences of Plasmodium falciparum reported to date. This gap in knowledge makes it difficult to understand the genetic dynamics of this pathogen in the past. The difficulty in identifying ancient malaria cases through bioarchaeology and the infrequent presence of Plasmodium DNA in ancient bones contribute to these limitations. Here, we present the first complete mtDNA genome of P. falciparum recovered from an archaeological skeleton (a 2nd century CE Roman individual from Italy). The study of the 43-fold mtDNA genome supports the hypothesis of an Indian origin for P. falciparum in Europe and provides evidence for the genetic continuity of this lineage over the past 2,000 years. Additionally, our research highlights that extensive sampling may be necessary for malaria screening to gain insights into the evolution of this vector-borne disease from archaeological samples.

genomics↗

bioRxiv2023

A Refined Phylochronology of the Second Plague Pandemic in Western Eurasia

Although dozens of ancient Yersinia pestis genomes and a vast corpus of documentary data are available, the origin and spread of consecutive outbreaks of the Second Plague Pandemic in Europe (14th-18th c.) are still poorly understood. For the majority of ancient genomes, only radiocarbon dates spanning several decades are available, hampering an association with historically recorded plague outbreaks. Here, we present new genomic evidence of the Second Pandemic from 11 sites in England, Estonia, the Netherlands, Russia, and Switzerland yielding 11 Y. pestis genomes with >4-fold mean coverage dating to between 1349 and 1710. In addition, we present a novel approach for integrating the chronological information retrieved from phylogenetic analysis with their respective radiocarbon dates, based on a novel methodology offering more precise dating intervals. Together with a fine-grained analysis of documentarily recorded plague outbreaks, this allows us to tentatively associate all available Y. pestis genomes of the Second Pandemic with historically documented plague outbreaks. Through these combined multidisciplinary analytical efforts, our newly sequenced genomes can be attributed to the Black Death in Cambridge (England), the pestis tertia or pestis quarta in the late 14th century (Estonia), previously unknown branches emerging in the 15th century (Estonia, the Netherlands and England), and a widespread pandemic in Eastern Europe around 1500 (western Russia), which all seem to have originated from one or multiple reservoirs located in Central Europe. While the latter continued to harbour a major Y. pestis lineage at least until the 1630s, represented by new genomes of the Thirty Years War plague (Switzerland), another lineage consecutively spread into Europe between the 17th and 18th century from the Ottoman Empire, as evidenced by a genome associated with the Great Northern War plague (Estonia). By combining phylogenetic analysis with a systematic historical reconstruction based on textual sources and an innovative phylogenetically informed radiocarbon modelling (PhIRM), we offer a new groundbreaking interdisciplinary approach that solves several fundamental methodological challenges associated with phylogenetic and spatio-temporal reconstruction of historical pandemics.

genomics↗

bioRxiv2022

Ancient herpes simplex 1 genomes reveal recent viral structure in Eurasia

Human herpes simplex virus 1 (HSV-1), a life-long infection spread by oral contact, today infects a majority of adults globally1, yet no ancient HSV-1 genomes have yet been published. Phylogeographic clustering of sampled diversity into European, pan-Eurasian, and African groups2, 3 has suggested that the virus co-diverged with anatomically modern humans migrating out of Africa4, although a much younger origin has also been proposed5. The lack of ancient HSV-1 genomes, high rates of recombination, and high mobility of humans in the modern era have impeded the understanding of HSV-1s evolutionary history. Here we present three full ancient European HSV-1 genomes and one partial genome, dating to between the 3rd and 17th century CE, sequenced to up to 9.5x with paired human genomes up to 10.16x. These HSV-1 strains fall within modern Eurasian diversity. We estimate a mean mutation rate of 7.6 x 10-7 - 1.13 x 10-6 for non-African diversity leading to an estimated age of sampled modern Eurasian diversity to 4.68 (3.87 - 5.65) kya. Extrapolation of these rates indicate the age of sampled HSV-1 to 5.29 (4.60-6.12 kya, suggesting lineage replacement coinciding with late Neolithisation and implicating Bronze Age migrations6 in the distribution of HSV-1 through Eurasia.

genomics↗