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Gallogly, S.

Publications and source records attributed to Gallogly, S..

13 recordsLinked to original sources
bioRxiv2026

Jamaican fruit bats are susceptible to henipaviruses but rapidly control infection

Henipaviruses (HNV), Hendra (HeV) and Nipah (NiV) virus, cause severe pulmonary and neurologic disease in humans and other mammals. Bats in the genus Pteropus naturally host HeV and NiV, but their feasibility in experimental studies is limited due to their large size, low fertility rate, and unavailability outside of their native range. Understanding bat-henipavirus interactions that regulate shedding and replication could improve mitigation of spillover events and illuminate the factors that differentiate severe and controlled HNV infection. Here, we assessed the suitability of the Jamaican fruit bat (JFB) (Artibeus jamaicensis) to model HNV infection in vitro and in vivo. JFB primary kidney cells were permissive to HNVs, and HeV and NiV antagonized the induction of the innate antiviral response. JFBs were inoculated via the intranasal and oral routes (IN/PO) with HeV or NiV or intravenously (IV) with HeV and monitored for 7 days. Following IN/PO exposure, infection was quenched rapidly and limited HeV RNA was detected in oral swabs and tissues while NiV RNA was found in only one oral swab. HeV IV inoculation resulted in robust, disseminated infection and viral RNA was detected in oral, rectal, and environmental swabs. Overall, these results support that JFBs are susceptible to both viruses, but replication is quenched rapidly in vivo following IN/PO exposure. Future studies will optimize the in vivo model to leverage the JFB to further our understanding of bat-henipavirus interactions. Author SummaryHenipaviruses (HNV) spillover from pteropid bat species and cause severe diseases in humans. Many gaps limit our understanding of HNV-bat interactions that influence spillover and effective control of infection. Here, we evaluate the Jamaican fruit bat (JFB) as a henipavirus model. We demonstrate that JFB cells are permissive all HNVs evaluated, and that JFBs support Hendra virus replication and shedding without signs of clinical disease.

microbiology↗
bioRxiv2025

Highly efficient anogenital transmission of clade Ia mpox virus associated with increased shedding.

The transmission pattern of mpox has shifted from sporadic zoonotic outbreaks to sustained human-to-human spread. Epidemiological data indicate sexual contact as a crucial driver for efficient transmission and the associated devastating mpox outbreaks in recent years. However, our understanding of exact driving factors and transmission determinants is still limited. Here, we investigated MPXV clade Ia virus pathogenicity, shedding kinetics, and transmission potential in a prairie dog model (Cynomys ludovicianus). All tested mucosal inoculation routes (penile/preputial, vaginal, rectal, intranasal) resulted in a productive, systemic infection. Inoculation via urogenital routes generated the highest virus shedding and most severe clinical disease. A simulated sexual contact transmission resulted in 100% transmission efficiency with high virus shedding in sentinels on day 1, even before the onset of clinical signs. Our findings provide critical insights into mpox transmission, emphasizing the role of anogenital mucosal surfaces in facilitating rapid spread. These results advocate for a stronger focus on mucosal infection when evaluating countermeasures.

microbiology↗
bioRxiv2025

Increased contact transmission of contemporary Human H5N1 compared to Bovine and Mountain Lion H5N1 in a hamster model

The ongoing outbreak of highly pathogenic avian influenza virus (HPAIV) subtype H5N1 in the U.S. poses a significant public health threat. To date, 70 human cases have been confirmed in the United States, including two severe cases and one fatality. While suitable animal models are crucial for predicting the potential pandemic risk of newly emerging pathogens in humans, studies investigating contemporary HPAIV H5N1 transmission dynamics remain limited. Here, we investigated the pathogenicity and transmission efficiency of three recent clade 2.3.4.4b H5N1 viruses isolated from a bovine, mountain lion, and a human case using Syrian hamsters. Intranasal inoculation with 104 TCID50 resulted in productive virus replication in the respiratory tract and shedding for all three isolates. Transmission studies showed limited efficiency via direct contact and airborne routes for all three isolates. Although overall transmission was inefficient, the human H5N1 isolate demonstrated relatively greater contact transmissibility than the bovine and mountain lion isolates. Taken together, our data demonstrate that the Syrian hamster model complements existing animal models for influenza A virus research and expands the resources available for investigating the pathogenicity, transmissibility, and efficacy of countermeasures against HPAIV H5N1. One sentence summaryHuman HPAIV H5N1 exhibits comparatively higher contact transmissibility than bovine and mountain lion isolates, despite limited overall transmission.

microbiology↗
bioRxiv2024

Enhanced encephalitic tropism of bovine H5N1 compared to the Vietnam H5N1 isolate in mice

In recent years, the landscape of highly pathogenic avian influenza (HPAI) virus infections has shifted, as evidenced by an increase in infections among mammals. This includes the recent circulation of H5N1 in dairy cattle herds in the USA and a rise in associated human cases. In this study, we investigated differences in tissue tropism of two HPAI H5N1 strains, the isolate A/Vietnam/1203/2004 (VN1203) isolated from a fatal human case in 2004 and the bovine isolate A/Bovine/Ohio/B24osu-342/2024 (Bov342) isolated in 2024, in C57BL/6J mice. Infection with either HPAI H5N1 isolate was uniformly lethal in mice. However, tissue tropism differed significantly: while VN1203 replication was largely restricted to the respiratory tract, Bov342 successfully replicated in the respiratory tract as well as various regions of the brain. Bov342-challenged animals exhibited clinical signs consistent with central nervous system (CNS) infection, and infectious virus was detected in brain tissue. Correspondingly, cytokine profiles in the brain differed significantly between the isolates. Notably, in addition to abundant evidence of CNS infection in Bov342-challenged mice via immunohistochemistry, sporadic intranuclear and intracytoplasmic immunoreactivity was observed in other tissues in the head, including the choroid plexus, retina, and inner ear. This study demonstrates that while both HPAI H5N1 isolates are uniformly lethal in C57BL/6J mice upon aerosol exposure, significant differences exist in tissue tropism, with Bov342 resulting in respiratory disease as well as increased neurotropism and inflammation in the brain and nasal turbinates compared to VN1203, which predominantly induces respiratory disease. Significance statementThe rise in HPAI H5N1 infections among mammals, including humans in the USA, highlights an emerging One Health concern. Understanding the phenotypic changes of HPAI H5N1 and associated increase in infection of mammalian hosts is critical. In this study, we investigated the tissue tropism in mice of a bovine HPAI H5N1 strain isolated in 2024 and compared it to a strain isolated from a human patient in 2004. Our findings reveal that the bovine isolate exhibits enhanced neurotropism, unlike the respiratory-restricted replication observed with the HPAI H5N1 isolate from 2004. This difference in tissue tropism, accompanied by distinct cytokine responses in the brain, underscores the potential for altered disease outcomes in other mammalian hosts.

microbiology↗
bioRxiv2024

Environmental stability of HPAIV H5N1 in raw milk, wastewater and on surfaces

H5N1 influenza outbreaks in dairy cows necessitate studying potential transmission routes among livestock and to humans. We measured the stability of infectious H5N1 influenza virus in raw milk, wastewater, and on contaminated surfaces. We found relatively slow decay in milk, indicating that contaminated milk and fomites pose plausible transmission risks.

microbiology↗
bioRxiv2024

Jamaican fruit bats (Artibeus jamaicensis) competence for Ebola virus but not Marburg virus is driven by intrinsic differences in viral entry and IFN-I signaling antagonism.

Ebola virus (EBOV) and Marburg virus (MARV) are zoonotic filoviruses that cause hemorrhagic fever in humans. Bat species in both Chiropteran suborders host filoviruses, suggesting that bats may have coevolved with this viral family. Correlative data implicate bats as natural EBOV hosts, but neither a full-length genome nor an EBOV isolate has been found in any bats sampled. Here, we modelled filovirus infection in the Jamaican fruit bat (JFB), Artibeus jamaicensis. Bats were inoculated with either EBOV or MARV through a combination of oral, intranasal, and subcutaneous routes. EBOV-infected bats supported systemic virus replication and shed infectious virus orally. In contrast, MARV replicated only transiently and was not shed. In vitro, JFB cells replicate EBOV more efficiently than MARV, and MARV infection induced innate antiviral responses that EBOV efficiently suppressed. Experiments using VSV pseudoparticles or replicating VSV expressing the EBOV or MARV glycoprotein demonstrated an advantage for EBOV entry and replication early, respectively, in JFB cells. Overall, this study describes filovirus species-specific phenotypes for both JFB and their cells.

immunology↗
bioRxiv2024

Evolution of Omicron lineage towards increased fitness in the upper respiratory tract in the absence of severe lung pathology

The emergence of the Omicron lineage represented a major genetic drift in SARS-CoV-2 evolution. This was associated with phenotypic changes including evasion of pre-existing immunity and decreased disease severity. Continuous evolution within the Omicron lineage raised concerns of potential increased transmissibility and/or disease severity. To address this, we evaluated the fitness and pathogenesis of contemporary Omicron variants XBB.1.5, XBB.1.16, EG.5.1, and JN.1 in the upper (URT) and lower respiratory tract (LRT). We compared in vivo infection in Syrian hamsters with infection in primary human nasal and lung epithelium cells and assessed differences in transmissibility, antigenicity, and innate immune activation. Omicron variants replicated efficiently in the URT but displayed limited pathology in the lungs compared to previous variants and failed to replicate in human lung organoids. JN.1 was attenuated in both URT and LRT compared to other Omicron variants and failed to transmit in the hamster model. Our data demonstrate that Omicron lineage evolution has favored increased fitness in the URT.

microbiology↗
bioRxiv2023

A bivalent Adenovirus-Vectored Vaccine induces a measurable humoral response, but does not protect cynomolgus macaques against a lethal challenge with Sudan virus

The most recent Sudan virus (SUDV) outbreak in Uganda was first detected in September 2022 and resulted in 164 laboratory-confirmed cases and 77 deaths. Currently, there are no approved vaccines or therapeutics against SUDV. In the current study, we investigated the protective efficacy of ChAdOx1-biEBOV in cynomolgus macaques using a prime or a prime-boost regimen. ChAdOx1-biEBOV is a replication-deficient simian adenovirus vector encoding SUDV and Ebola virus (EBOV) glycoproteins (GPs) at the E1 and E4 loci, respectively. Intramuscular vaccination induced SUDV and EBOV GP-specific IgG responses and neutralizing antibodies. Upon challenge with SUDV, vaccinated animals, regardless of vaccination scheme, showed signs of disease like those observed in control animals, and no difference in survival outcomes were measured among all three groups. Viral load in blood samples and in tissue samples obtained after necropsy were not significantly different between groups. Overall, this study highlights the importance of evaluating vaccines in multiple animal models, including nonhuman primates, and demonstrates the importance of understanding protective efficacy in both animal models and human hosts.

microbiology↗
bioRxiv2023

Environmental Persistence and Disinfection of Lassa Virus

Lassa Fever, caused by Lassa virus (LASV), is endemic to West Africa, where approximately 300,000 illnesses and 5,000 deaths occur annually. LASV is primarily spread by infected multimammate rats via urine and fomites, highlighting the importance of understanding the environmental fate of LASV. This study evaluated the persistence of LASV strains on surfaces in aqueous solutions and with sodium hypochlorite disinfection. LASV strains (Josiah and Sauerwald) were more stable in DI water (k = 0.23 and 0.34 days-1) than primary influent wastewater (k = 1.3 and 1.9 days-1). The decay rates of LASV on HDPE (k = 4.3 and 2.3 days-1) and Stainless Steel (k = 5.3 and 2.7 days-1) were not significantly different for either strain. Sodium hypochlorite was highly effective at inactivating both strains of LASV. This work presents data for the environmental persistence of LASV to inform future risk assessment and management efforts.

microbiology↗
bioRxiv2023

Stability of mpox (monkeypox) virus in bodily fluids and wastewater

ImportanceSince May 2022, human monkeypox (mpox) infections have spread rapidly outside endemic countries. On July 23, 2023, WHO declared a Public Health Emergency of international Concern because of the unprecedented global spread of mpox. Whereas there is an incomplete understanding of transmission routes, the spread of monkeypox virus (MPXV) through sexual contact networks of men who have sex with men (MSM) highlights the potential of transmission during sexual activity, either via bodily fluids or via direct contact. This research assesses the potential for MPXV to remain infectious in the environment on surfaces and in fluids under different environmental conditions. ObjectiveTo investigate the stability of MPXV on various surfaces, at different environmental conditions and in different bodily fluids (human blood, semen, serum, saliva, urine, and feces), and to assess decontamination of MPXV-contaminated wastewater via chlorination. Design, Setting, and ExposuresAll experiments involving viable MPXV were performed at the Rocky Mountains Laboratory under high containment conditions using MPXV strain hMPXV/USA/MA001. Infectious MPXV was quantified via plaque assay. Environmental decay rates were estimated using a Bayesian statistical model, with a Poisson likelihood for plaque counts. ResultsMPXV showed surface dependent stability, with faster decay at higher temperatures. Decay rates varied considerably depending on the medium in which virus was suspended, both overall MPXV displayed considerable environmental stability in bodily fluids and in particular proteinaceous fluids, such as blood and semen, lead to greater persistence. Wastewater chlorination was an effective decontamination technique. Conclusions and RelevanceMPXV retains its infectivity in the environment when it is deposited in blood, semen, and serum; environmental decay is more rapid in less proteinaceous fluids, particularly once residual liquid has evaporated. The observed persistence of MPXV implies environmental contamination in healthcare setting, could serve as vehicles of transmission and dissemination in these environments. Chlorination was effective in decontamination of wastewater. Key findings and public health implications; these results suggest that MPXV can have prolonged stability in the environment and are therefore directly relevant for hospital hygiene practices to prevent nosocomial transmission.

microbiology↗
bioRxiv2023

Rectal and vaginal challenge with mpox virus increases virus dissemination and contact transmission compared to skin challenge in the multimammate rat (Mastomys natalensis)

The 2022 mpox virus outbreak was sustained by efficient human-to-human transmission and spread predominantly through sexual networks of men who have sex with men (MSM). It is currently unclear what combination of factors resulted in the enhanced transmission. To investigate this, we established the peridomestic African rodent Mastomys natalensis as a new rodent model susceptible to infection after intraperitoneal, rectal, vaginal, and transdermal inoculation with an early 2022 human outbreak isolate (Clade IIb). Route-dependent shedding and tissue replication occurred in the presence of self-resolving localized skin, reproductive tract, or rectal lesions. Mucosal inoculation via both the rectal and vaginal route led to increased shedding compared to skin inoculation, and increased replication and a proinflammatory T-cell profile. Contact transmission was higher in rectally inoculated animals. This suggests that the spread in MSM communities may have been enhanced by increased susceptibility of the anal and genital mucosae for infection and subsequent virus release.

microbiology↗
bioRxiv2022

SARS-CoV-2 Omicron BA.1 and BA.2 are attenuated in rhesus macaques as compared to Delta

Since the emergence of SARS-CoV-2, five different variants of concern (VOCs) have been identified: Alpha, Beta, Gamma, Delta, and Omicron. Due to confounding factors in the human population, such as pre-existing immunity, comparing severity of disease caused by different VOCs is challenging. Here, we investigate disease progression in the rhesus macaque model upon inoculation with the Delta, Omicron BA.1, and Omicron BA.2 VOCs. Disease severity in rhesus macaques inoculated with Omicron BA.1 or BA.2 was lower than those inoculated with Delta and resulted in significantly lower viral loads in nasal swabs, bronchial cytology brush samples, and lung tissue in rhesus macaques. Cytokines and chemokines were upregulated in nasosorption samples of Delta animals compared to Omicron BA.1 and BA.2 animals. Overall, these data suggests that in rhesus macaques, Omicron replicates to lower levels than the Delta VOC, resulting in reduced clinical disease.

microbiology↗