Biology subjects

Geraerts, M.

Publications and source records attributed to Geraerts, M..

4 recordsLinked to original sources

bioRxiv2025

High genetic diversity of mpox virus (MPXV) in three different rodent species in the Democratic Republic of the Congo (DRC)

Altough zoonotic spillover events continue to drive human mpox outbreaks in the Democratic Republic of the Congo (DRC), the wildlife reservoir of mpox virus (MPXV) remains unkown. To address this gap, we screened samples from 2,701 wild mammals, mainly rodents (59.7%), bats (26.4%) and shrews (12.1%). Only six (0.2%) animals were Orthopoxvirus (OPV) PCR positive. Near full-length MPXV sequences were obtained from two squirrels (Funisciurus anerythrus and Paraxerus sp.) and one soft furred mouse (Praomys jacksoni). A novel Taterapox virus was identified in a shrew (Crocidura cf. denti). All newly identified MPXV strains belong to clade Ia, but they cluster into different groups or subgroups, despite being collected from geographically close locations, and all are closely related to human MPXV strainsfrom the same regions. Our study provides for the first time clear evidence that MPXV diversity is not restricted to a single rodent host species nor confined to a geographic area. Importantly, MPXV positive Paraxerus and Praomys specimens were sampled close to Kisangani, a city with more than one million inhabitants, highlighting that spillover events can als ooccur in or near major cities, with more favorable conditions for interhuman transmissions and potential emergence of new lineages.

microbiology↗

bioRxiv2024

A wide diversity of viruses detected in African mammals involved in the wild meat supply chain

The processes involved in acquiring, trading, preparing, and consuming wild meat pose significant risks for the emergence of zoonotic infectious diseases. Several major viral outbreaks have been directly linked to the wild meat supply chain, yet our knowledge of the virome in many mammals involved in this chain remains limited and disproportionately focused on certain mammalian taxa and pathogens. This report presents the findings of a metagenomic viral screening of 99 specimens belonging to 27 wild African mammal species and one domesticated species, all traded for their meat. The study focuses on tissue and swab samples collected from various regions in the Democratic Republic of the Congo and in Brussels, Belgium. A total of fifteen virus strains were detected, belonging to the families Arteriviridae, Retroviridae and Sedoreoviridae (primates), Picobirnaviridae (primates and rodents), Picornaviridae (rodents), Hepadnaviridae (hyrax), Orthoherpesviridae (artiodactylid and carnivore) and Spinareoviridae (carnivore). Several strains were detected in mammalian hosts for the first time, expanding their host range and genetic diversity. Of note is the presence of viruses genetically related to recognised zoonotic pathogens, i.e., human picobirnavirus (Orthopicobirnavirus hominis) (primates and rodents), simian foamy viruses (Simiispumavirus) (primates), and rotavirus A (Rotavirus alphagastroenteritidis) (primates). The presence of these viruses in primates is concerning as non-human primates are phylogenetically closely related to humans, which can facilitate interspecies viral transmission. These findings underscore the high diversity of mammalian viruses and the potential risk of human infection through cross-species transmission during the close interactions with wildlife in the wild meat supply chain.

genomics↗

bioRxiv2023

From scalp to cortex, the whole isn't greater than the sum of its parts: introducing GetTissueThickness (GTT) to assess age and sex differences in tissue thicknesses

Noninvasive techniques to record and stimulate the brain rely on passing through the tissues in between the scalp and cortex. Currently, there is no method to obtain detailed information about these scalp-to-cortex distance (SCD) tissues. We introduce GetTissueThickness (GTT), an open-source, automated approach to quantify SCD, and unveil how tissue thicknesses differ across age groups, sexes and brain regions (n = 250). We show that men have larger SCD in lower scalp regions and women have similar-to-larger SCD in regions closer to the vertex, with aging resulting in increased SCD in fronto-central regions. Soft tissue thickness varies by sex and age, with thicker layers and greater age-related decreases in men. Compact and spongy bone thickness also differ across sexes and age groups, with thicker compact bone in women in both age groups and an age-related thickening. Older men generally have the thickest cerebrospinal fluid layer and younger women and men having similar cerebrospinal fluid layers. Aging mostly results in grey matter thinning. Concerning SCD, the whole isnt greater than the sum of its parts. GTT enables rapid quantification of the SCD tissues. The distinctive sensitivity of noninvasive recording and stimulation modalities to different tissues underscores the relevance of GTT.

neuroscience↗

bioRxiv2022

A new species of Cichlidogyrus Paperna, 1960 (Platyhelminthes: Monogenea: Dactylogyridae) infecting tilapias in Lake Kariba (Zimbabwe), with a discussion on its phylogenetic position

Monogeneans dominate the external parasite fauna of bony fish. During recent years, examination of more populations of species of Cichlidogyrus Paperna, 1960 has led to the (re)description of several species. Cichlidogyrus halli (Price & Kirk, 1967) Price, 1968, for example, has been redescribed several times in the past and has been proposed to encompass many (pseudo)cryptic species. In Lake Kariba (Zimbabwe), specimens of a species of Cichlidogyrus were found that morphologically resemble C. halli. These specimens were found on the gills of native Oreochromis cf. mortimeri and Coptodon rendalli (Boulenger, 1897), and introduced Nile tilapia Oreochromis niloticus (Linnaeus, 1758). A detailed study of the morphology of these specimens, including morphometrics, and a thorough comparison with specimens of C. halli is presented. Part of the COI gene and 18S-ITS1 fragment were sequenced and analysed to provide insight into the phylogenetic placement of these specimens within the Cichlidogyrus-Scutogyrus monophylum. We found that C. halli and the new specimens sp. nov. are sister clades within the same monophyletic clade, and that clear morphological and morphometric differences are present in the dorsal bar of the haptor and accessory piece of the male copulatory organ. Based on these results, the new specimens are described as a new species: C. chloeae sp. nov. The role of introduced Nile tilapia as a potential reservoir for native parasites raises concern for potential spillbacks and stresses the need for further monitoring of monogeneans on native and introduced tilapias.

zoology↗