ETIDIOH - NEW

  Abstract Bats are associated with some of the most significant and virulent emerging zoonoses globally , yet research and surveillance of bat pathogens remains limited across parts of the world. We surveyed the prevalence and genetic diversity of coronaviruses from bats in Taita Hills, southeastern Kenya , as part of ongoing surveillance efforts in this remote part of eastern Africa. We collected fecal and intestinal samples in May 2018 and March 2019 from 16 bat species . We detected one genus of coronavirus (alphacoronavirus), with an overall RNA prevalence of 6.5% (30/463). The prevalence of coronavirus RNA was 3.8% (9/235) and 11.6% (21/181) for the two most captured free-tailed bat species, Mops condylurus and M. pumilus respectively, with no detections from other bat species (0/90). Phylogenetic analyses based on the partial RNA-dependent RNA polymerase gene and whole genome sequences revealed that the sequences clustered together and were closely related to alphacoronaviru...

  Abstract Dipeptidyl peptidase-4 (DPP4) is an established receptor for Middle East respiratory syndrome-related coronaviruses (MERSr-CoVs), while recent studies have identified angiotensin-converting enzyme 2 (ACE2) usage in multiple merbecovirus clades . Yet, receptor usage of many genetically diverse bat MERSr-CoVs remains unclear . Here we show that broadly distributed HKU25 clade merbecoviruses use ACE2 , rather than DPP4, as their receptor. Cryo-electron microscopy revealed that HsItaly2011 and VsCoV-a7 strains engage ACE2 similarly to HKU5 but with remodelled interfaces and distinct orthologue selectivity, suggesting a shared evolutionary origin of ACE2 recognition . EjCoV-3, a close relative of the DPP4-using BtCoV422, showed broad multi-species ACE2 tropism and preadaptation to human ACE2 . Several ACE2 glycans and residues within or near the binding interface were identified as determinants of orthologue selectivity. These viruses remain sensitive to several broadly neutr...

  Abstract SARS-like betacoronaviruses (sarbecoviruses) endemic in bats pose a significant zoonotic threat to humans . Genetic pathways associated with spillover of bat sarbecoviruses into humans are incompletely understood. We previously showed that the wild-type spike of the rhinolophid bat coronavirus SHC014-CoV has poor entry activity and uncovered two distinct genetic pathways outside the receptor-binding domain (RBD) that increased spike opening, ACE2 binding , and cell entry. Herein, we show that the widely studied bat sarbecovirus WIV1-CoV is likely a cell culture-adapted variant whose progenitor bears a spike resembling that of Rs3367-CoV, which was sequenced from the same population of rhinolophid bats as SHC014-CoV. Our findings suggest that the acquisition of a single amino-acid substitution in the ‘630-loop’ of the S1 subunit was the key spike adaptation event during the successful isolation of WIV1-CoV, and that it enhances spike opening, virus-receptor recognition, a...

  Abstract Background :  In Mexico, two Mammarenavirus genotypes have been identified : Real de Catorce virus and Ocozocoautla de Espinosa virus (OCEV), which are found in rodents (Neotoma leucodon and Peromyscus mexicanus). Mammarenaviruses from clade B cause mild to severe infectious diseases in humans , particularly in South America. A 1967 outbreak in Chiapas, Mexico, was potentially linked to the OCEV. Materials and Methods :  Between 2017 and 2020, we collected bats across southern/southeastern Mexico to identify Mammarenavirus reservoirs. We analyzed 81 liver samples from 14 bat species using nested PCR. For quality control, we synthesized and OCEV S-region fragment into an ampicillin-resistant pUC57 plasmid, cloned in One Shot Stbl3 chemically competent E. coli. Results :  Here, we report the first detection of a Mammarenavirus (OCEV) in an Artibeus lituratus bat from Sabancuy, Campeche , southeastern Mexico. This finding represents the third Mammarenavirus r...

  Abstract We describe isolation and characterization of a novel henipavirus , designated Salt Gully virus , from the urine of pteropid bats in Australia . We noted the virus to be most closely related to Angavokely virus, not reliant on ephrin receptors for cell entry, and of unknown risk for human disease. Source: US Centers for Disease Control and Prevention,  https://wwwnc.cdc.gov/eid/article/31/9/25-0470_article ____

  ABSTRACT Bats are the reservoir hosts of emerging coronaviruses (CoVs) affecting human and livestock health . We assessed the diversity, evolution, and geographic distribution of two alphacoronaviruses (subgenus Rhinacovirus ) with considerable potential for emergence : swine acute diarrhea syndrome coronavirus ( SADS-CoV ), which has caused large outbreaks in pigs in China and can infect primary human airway epithelial cells in vitro ; and the related Rhinolophus bat coronavirus HKU2 (HKU2-CoV). Phylogenetic analyses of 523 rhinacovirus sequences from bats in China and Southeast Asia suggest these viruses should be reclassified into at least two distinct CoV species representing two well-supported monophyletic clades. Stronger phylogenetic clustering by sampling location than by host species suggests infrequent long-distance transmission of rhinacoviruses in southern China. Ancestral state reconstruction analysis indicates that R. sinicus/thomasi and R. affinis have played an im...

  Abstract Background Bats are recognized as natural reservoir hosts for numerous viruses and are believed to be the evolutionary origin of alpha- and beta-coronaviruses (CoVs), such as SARS-CoV, SARS-CoV-2, and possibly MERS-CoV. MERS-related beta-CoVs have been identified in bat species from Africa, America, Asia, and Europe. In this study, we describe the first detection and characterization of a MERS-related beta-CoV in Danish brown long-eared bats (Plecotus auritus). Methods Fecal samples collected through a national surveillance program were screened using pan-CoV RT-qPCRs. Positive samples underwent ORF1b sequencing, microarray analysis and Illumina MiSeq sequencing, followed by metagenomic assembly of full-length genomes. A global phylogenetic tree was used to determine placement within the Coronaviridae family and local maximum likelihood phylogenetic analysis clarified subgroup placement. The receptor-binding potential of the spike protein to human DPP4, ACE2, and bat ACE...

Abstract The zoonotic transmission of bat coronaviruses poses a threat to human health. However, the diversity of bat-borne coronaviruses remains poorly characterized in many geographical areas. Here, we recovered eight coronavirus genomes by performing a metagenomic analysis of fecal samples from hundreds of individual bats captured in Spain , a country with high bat diversity. Three of these genomes corresponded to potentially novel coronavirus species belonging to the alphacoronavirus genus . Phylogenetic analyses revealed that some of these viruses are closely related to coronaviruses previously described in bats from other countries, suggesting a shared viral reservoir worldwide. Using viral pseudotypes, we investigated the receptor usage of the identified viruses and found that one of them can use human ACE2 , albeit with lower affinity than SARS-CoV-2. However, the receptor usage of the other viruses remains unknown. This study broadens our understanding of coronavirus diversity...

Abstract Identifying receptors for bat coronaviruses is critical for spillover risk assessment, countermeasure development, and pandemic preparedness . While Middle East respiratory syndrome coronavirus ( MERS-CoV ) uses DPP4 for entry , the receptors of many MERS-related betacoronaviruses remain unknown . The bat merbecovirus HKU5 was previously shown to have an entry restriction in human cells . Using both pseudotyped and full-length virus, we show that HKU5 uses Pipistrellus abramus bat ACE2 but not human ACE2 or DPP4 as a receptor. Cryo-electron microscopy analysis of the virus-receptor complex and structure-guided mutagenesis reveal a spike and ACE2 interaction that is distinct from other ACE2-using coronaviruses. MERS-CoV vaccine sera poorly neutralize HKU5 informing pan-merbecovirus vaccine design. Notably, HKU5 can also engage American mink and stoat ACE2 , revealing mustelids as potential intermediate hosts. These findings highlight the versatility of merbecovirus receptor use...

Abstract We sequenced sarbecovirus from Rhinolophus spp. bats in Bandarban District , Bangladesh, in a genomic surveillance campaign during 2022–2023. Sequences shared identity with SARS-CoV-1 Tor2, which caused an outbreak of human illnesses in 2003 . Describing the genetic diversity and zoonotic potential of reservoir pathogens can aid in identifying sources of future spillovers. Source: US Centers for Disease Control and Prevention,  https://wwwnc.cdc.gov/eid/article/31/8/25-0071_article ____

Abstract In 2014, an outbreak of zoonotic Nipah virus (NiV) occurred on Mindanao Island , the Philippines . We investigated the prevalence of NiV in Philippine bats . Because neutralizing antibodies were detected in insectivorous bats on Siargao Island , public health officials should consider that the distribution range of NiV is not limited to Mindanao Island. Source: US Centers for Disease Control and Prevention,  https://wwwnc.cdc.gov/eid/article/31/8/25-0210_article ____

Abstract Bats are natural reservoirs for a wide range of microorganisms, including many notable zoonotic pathogens. However, the composition of the infectome (i.e., the collection of viral, bacterial and eukaryotic microorganisms) within bat kidneys remains poorly understood. To address this gap, we performed meta-transcriptomic sequencing on kidney tissues from 142 bats , spanning ten species sampled at five locations in Yunnan province, China . This analysis identified 22 viral species , including 20 novel viruses , two of which represented newly discovered henipaviruses closely related to the highly pathogenic Hendra and Nipah viruses . These henipaviruses were found in the kidneys of bats inhabiting an orchard near villages, raising concerns about potential fruit contamination via bat urine and transmission risks to livestock or humans. Additionally, we identified a novel protozoan parasite, tentatively named Klossiella yunnanensis , along with two highly abundant bacterial species...

ABSTRACT Betacoronaviruses, which have caused three human outbreaks within the last two decades, are thought to originate from bats , raising the concern that bat coronaviruses could cause a novel human outbreak in the future. To determine whether the bat merbecovirus EjCoV-3 strain , previously detected in Eptesicus japonensis in Japan , has the potential to infect humans, we analyzed its cellular entry mechanism. Cellular entry of EjCoV-3 via the spike protein requires protease treatment and is mediated by an unknown receptor, other than DPP4 or ACE2 . We generated cultivable recombinant EjCoV-3 using bacterial artificial chromosome-based reverse genetics and found that it efficiently replicated in human respiratory and intestinal cell cultures as well as nasal ciliated epithelium in hamsters. These findings suggest that bat merbecovirus with ACE2- and DPP4-independent cell entry has the potential to cause human infections , highlighting the importance of extensive bat surveillance f...

Abstract Bats are the natural reservoirs for a variety of emerging and re-emerging viruses. Among them, rabies virus (genus Lyssavirus, family Rhabdoviridae) is one of the first and most emblematic described in these animals. Since its first description, several new bat lyssaviruses have been regularly identified. In addition to lyssaviruses, other bat rhabdoviruses have also been discovered, including members of the genera Vesiculovirus , Ledantevirus and, more recently, Alphanemrhavirus and Tupavirus . However, the family Rhabdoviridae is one of the most abundant and diverse viral families, with 434 officially recognized species , divided into 5 subfamilies and 56 different genera . The number of rhabdoviruses associated with bats is therefore probably higher than that currently available. In this study, we first developed and validated a combined nested RT-qPCR technique (pan-rhabdo RT-nqPCR) dedicated to the broad detection of animal rhabdoviruses. After validation, this technique ...

Abstract Despite accumulating evidence that bat-derived coronaviruses often require intermediate hosts to facilitate transmission to humans1, the potential role of fur animals in zoonotic coronavirus spillovers has largely been overlooked2. Here we report the isolation and characterization of a novel mink respiratory coronavirus (MRCoV) from farmed minks with pneumonia . Notably, MRCoV uses angiotensin-converting enzyme 2 (ACE2) as a receptor and can infect mink, bat, monkey, and human cells . Cryo-electron microscopy analysis revealed that the MRCoV receptor-binding domain (RBD) binds to the same interface on ACE2 receptors as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RBD , despite exhibiting notable structural differences. We identify the key determinants on ACE2 and MRCoV RBD that confer efficient binding. HKU5-33S, a bat coronavirus closely related to MRCoV , utilizes ACE2 of bat Pipistrellus abramus and requires only two amino acid substitutions to adapt to mink...

Abstract Prior to the discovery of bat influenza A virus (IAV) subtypes H17N10 and H18N11 , all IAVs were thought to bind sialic acid residues via hemagglutinin (HA) to mediate attachment and subsequent viral entry. However, H17 and H18 engage a proteinaceous receptor : the major histocompatibility complex class II (MHCII). The mechanistic details of this hitherto unknown protein-mediated entry are not understood. Given that conventional IAVs rely on multivalent binding to sialylated glycans , we hypothesized that bat HA similarly interacts with multiple MHCII molecules. Using photoactivated localization microscopy (PALM) on fixed and live cells, we demonstrate that bat IAV particles attach to pre-existing MHCII clusters and induce a further increase in cluster size upon binding. To measure the impact of viral attachment on the dynamics of MHCII, we employ an “inverse attachment” approach, immobilizing viral particles on coverslips before seeding live MHCII-expressing cells on top. Sin...

Abstract We performed serologic surveillance for selected arthropod-borne viruses (arboviruses) in bats and opossums in the Lacandona Rainforest, Chiapas, Mexico , in 2023–2024. Sera were collected from 94 bats of at least 15 species and 43 opossums of three species. The sera were assayed by the plaque reduction neutralization test (PRNT) for antibodies to eight orthoflaviviruses ( dengue viruses 1–4, St. Louis encephalitis virus , T’Ho virus, West Nile virus, and Zika virus ) and one alphavirus (chikungunya virus; CHIKV). Twelve (12.8%) bats and 15 (34.9%) opossums contained orthoflavivirus-specific antibodies . One bat (a Jamaican fruit bat) was seropositive for Zika virus , and 11 bats contained antibodies to an undetermined orthoflavivirus , as did the 15 opossums. All bats and most opossums seropositive for an undetermined orthoflavivirus had low PRNT titers, possibly because they had been infected with another (perhaps unrecognized) orthoflavivirus not included in the PRNTs. Anti...

Abstract 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 Cambodia’s 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 potentia...

Abstract SARS-like betacoronaviruses (sarbecoviruses) endemic in bats pose a significant zoonotic threat to humans . Genetic pathways associated with spillover of bat sarbecoviruses into humans are incompletely understood. We previously showed that the WT spike of the rhinolophid bat coronavirus SHC014 -CoV has poor entry activity and uncovered two distinct genetic pathways outside the receptor-binding domain (RBD) that increased spike opening, ACE2 binding , and cell entry. Herein, we show that the widely studied bat sarbecovirus WIV1-CoV is likely a cell culture-adapted variant of Rs3367-CoV, which was sequenced from the same population of rhinolophid bats as SHC014-CoV. We demonstrate that the acquisition of a single amino-acid substitution in the ‘630-loop’ of the S1 subunit was the key spike adaptation event during the successful isolation of WIV1-CoV, and that it enhances spike opening, virus-receptor recognition, and cell entry in much the same manner as the substitutions we pre...

Abstract We report 1.3% (19/1,511) of Egyptian rousette bats (ERBs) in Uganda and Sierra Leone were co-infected with different combinations of Marburg, Sosuga, Kasokero, or Yogue viruses . To prevent infection by those viruses, we recommend avoiding ERB-populated areas, avoiding ERBs and ERB-contaminated objects, and thoroughly washing harvested fruits before consumption. Source: US Centers for Disease Control and Prevention,  https://wwwnc.cdc.gov/eid/article/31/5/24-1669_article ____