Biology subjects

Auerswald, H.

Publications and source records attributed to Auerswald, H..

5 recordsLinked to original sources

bioRxiv2025

Discovery of a Novel Coltivirus in a Newly Identified Bat Bug Species (Heteroptera: Cimicidae) in Cambodia

Bats and their ectoparasites are significant reservoirs and potential vectors of emerging zoonotic pathogens, yet the viral diversity within bat-associated arthropods remains poorly characterized. This study reports the identification of a novel coltivirus (order Reovirales), provisionally designated Stricticimex coltivirus (SCCV), in a newly described bat bug species, Stricticimex phnomsampovensis, collected from cave-dwelling wrinkle-lipped free-tailed bats (Mops plicatus) in Cambodia. Metagenomic sequencing and phylogenetic analysis revealed that SCCV clusters within the Coltivirus genus, showing closest similarity to Tai Forest Reovirus (TFRV) previously isolated from African bats. SCCV was detected in 18.4% of examined bat bugs and successfully isolated in VeroE6 cells, with replication confirmed in multiple mammalian cell lines. The discovery of SCCV extends the known diversity and geographic range of Coltivirus and highlights bat ectoparasites as overlooked hosts of potentially zoonotic viruses. These findings underscore the importance of integrated One Health surveillance targeting both bats and their ectoparasites to better assess the risk of pathogen spillover in biodiverse regions with high human-animal contact. Author SummaryIn this study, we identify a novel Coltivirus, named Stricticimex coltivirus (SCCV), in a newly described bat bug species collected from cave-dwelling bats in Cambodia. Using metagenomic sequencing and phylogenetic analysis, we find that SCCV is closely related to Tai Forest Reovirus, previously identified in African bats. We successfully isolated the virus in mammalian cell lines, suggesting potential to infect vertebrate hosts. This discovery not only expands the known diversity of Coltiviruses, but also underscores the role of bat ectoparasites as underexplored reservoirs of potentially zoonotic viruses. Our findings emphasize the importance of integrated One Health surveillance efforts targeting both bats and their ectoparasites to better assess the risk of virus spillover in regions where human and wildlife habitats overlap.

microbiology↗

bioRxiv2025

Characterization and evolutionary history of novel SARS-CoV-2-related viruses in bats from Cambodia

Circulating bat coronaviruses present a significant pandemic threat, yet our understanding of their genetic diversity and evolutionary dynamics remains limited. Over 3 years, we sampled 1,462 bats in Cambodias Steung Treng province, identifying extensive and diverse coronaviruses co-circulation. Using metatranscriptomic and amplicon sequencing, we generated 33 complete sarbecovirus genomes, revealing novel lineages that cluster into four distinct groups, each associated with different Rhinolophus bat species. Our analysis highlights rapid migration and recombination of sarbecovirus lineages over short distances and timescales. Of note, the receptor-binding domains of two novel viral groups exhibit high similarity to SARS-CoV-2, and pseudovirus assays confirmed the ability of this spike protein to mediate entry into cells expressing human ACE2, suggesting a potential zoonotic risk. The observed genetic diversity underscores the urgent need for continuous surveillance to identify high-risk animal-to-human interfaces and inform pandemic preparedness.

microbiology↗

bioRxiv2024

Insect-specific Alphamesonivirus-1 (Mesoniviridae) in lymph node and lung tissues from two horses with acute respiratory syndrome

As members of the RNA virus order Nidovirales include those that infect hosts ranging from marine invertebrates to terrestrial mammals, understanding their emergence, host range and disease potential is of clear importance. The Mesoniviridae are a recently documented family of viruses within the Nidovirales. To date, mesoniviruses have only been associated with the infection of arthropods, particularly mosquitoes. Herein, we report the first detection of a mesonivirus - Alphamesonivirus-1 - in mammals. Specifically, we utilized genomic and histological techniques to identify the presence of Alphamesonivirus-1 in lung and lymph node tissues of two horses that succumbed to an acute respiratory syndrome. Notably, no other pathogens typically associated with respiratory disease in horses were detected in these samples. Counter to the previous contention that mesoniviruses only infect insects, our findings suggest a potentially broader host range and cross-species transmission of these viruses. The genome sequences of Alphamesonivirus-1 obtained from the two horses were closely related to those from a local Culex mosquito pool as well as an Alphamesonivirus-1 previously in identified Italy, suggestive of ongoing local transmission. The discovery of Alphamesonivirus-1 in tissues from diseased horses not only challenges current understandings of mesonivirus host range, but prompts further investigation into the role of insect-specific viruses in mammalian disease processes. Our results emphasize the importance of considering atypical pathogens in cases of unexplained animal deaths and suggest a potential zoonotic threat posed by previously overlooked viral families. IMPORTANCEAlphamesoniviruses, members of the Mesoniviridae family, have long been considered insect-specific viruses with no known association with vertebrate hosts. Herein, we describe the first detection of Alphamesonivirus-1 in mammals, marking a significant expansion of the known host range for this newly described virus family. Using detailed molecular and histological analyses we identified Alphamesonivirus-1 in lung and lymph node tissues of two horses that presented with an acute respiratory syndrome. Our findings indicate that Alphamesoniviruses may possess a broader host range than previously believed and could potentially induce severe disease in mammals. This unexpected host jump not only challenges existing knowledge on the ecology of mesoniviruses, but suggests that insect-specific viruses may pose a previously unrecognized health risk to vertebrates, including domesticated animals. These insights prompt the need for increased surveillance of atypical pathogens, especially in cases of unexplained respiratory illness, and may have implications for zoonotic disease emergence.

microbiology↗

bioRxiv2021

Robust and Functional Immunity up to 9 months after SARS-CoV-2 infection: a Southeast Asian longitudinal cohort

Assessing the duration of humoral and cellular immunity remains key to overcome the current SARS-CoV-2 pandemic, especially in understudied populations in least developed countries. Sixty-four Cambodian individuals with laboratory-confirmed infection with asymptomatic or mild/moderate clinical presentation were evaluated for humoral immune response to the viral spike protein and antibody effector functions during acute phase of infection and at 6-9 months follow-up. Antigen-specific B cells, CD4+ and CD8+ T cells were characterized, and T cells were interrogated for functionality at late convalescence. Anti-spike (S) antibody titers decreased over time, but effector functions mediated by S-specific antibodies remained stable. S- and nucleocapsid (N)-specific B cells could be detected in late convalescence in the activated memory B cell compartment and are mostly IgG+. CD4+ and CD8+ T cell immunity was maintained to S and membrane (M) protein. Asymptomatic infection resulted in decreased ADCC and frequency of SARS-CoV-2-specific CD4+ T cells at late convalescence. Whereas anti-S antibodies correlated with S-specific B cells, there was no correlation between T cell response and humoral immunity. Hence, all aspects of a protective immune response are maintained up to nine months after SARS-CoV-2 infection in the absence of re-infection. One sentence summaryFunctional immune memory to SARS-CoV-2, consisting of polyfunctional antibodies, memory B cells and memory T cells are maintained up to nine months in a South-East Asian cohort in the absence of re-infection.

immunology↗

bioRxiv2020

Assessment of Inactivation Procedures for SARS-CoV-2

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of Coronavirus disease 2019 (COVID-19), presents a challenge to laboratorians and healthcare workers around the world. Handling of biological samples from individuals infected with the SARS-CoV-2 virus requires strict biosafety and biosecurity measures. Within the laboratory, non-propagative work with samples containing the virus requires, at minimum, Biosafety Level-2 (BSL-2) techniques and facilities. Therefore, handling of SARS-CoV-2 samples remains a major concern in areas and conditions where biosafety and biosecurity for specimen handling is difficult to maintain, such as in rural laboratories or austere field testing sites. Inactivation through physical or chemical means can reduce the risk of handling live virus and increase testing ability worldwide. Herein we assess several chemical and physical inactivation techniques employed against SARS-CoV-2 isolates from Cambodian COVID-19 patients. This data demonstrates that all chemical (AVL, inactivating sample buffer and formaldehyde) and heat treatment (56{degrees}C and 98{degrees}C) methods tested completely inactivated viral loads of up to 5 log10.

microbiology↗