bioRxiv Science⌕ Search

bioRxiv · 10.1101/2023.06.15.545196

Low gH/gL (sub)species-specific antibody levels indicate elephants at risk of fatal elephant endotheliotropic herpesvirus hemorrhagic disease

Abstract

Elephant endotheliotropic herpesviruses (EEHVs), of which seven species and multiple subspecies are currently distinguished, naturally infect either Asian (Elephas maximus) or African elephants (Loxodonta species). While all adult elephants are latently infected with at least one EEHV (sub)species, EEHV infections in young elephants may lead to acute, fatal hemorrhagic disease (EEHV-HD). The disease is primarily observed in calves with low to non-detectable EEHV-specific antibodies, suggesting it is the result of an uncontrolled primary infection. Yet, young elephants showing high antibody levels in serological assays based on EEHV(1A) gB, which detect antibodies against multiple EEHV (sub)species, are not necessarily protected against EEHV-HD. To better determine which animals are at risk of EEHV-HD, we developed gB and gH/gL ELISAs for all Asian elephant EEHV (sub)species and assessed their specificity using 396 sera from 164 Asian elephants kept in Europeans zoos. Antibody levels measured against gB of different EEHV (sub)species correlated strongly with one another, indicating gB-specific antibodies are highly cross-reactive. In contrast, antibody responses towards gH/gL of different EEHV (sub)species were far less correlated and could be used to distinguish between infections with different (sub)species. Subsequently, antibody responses in sera of 23 EEHV-HD fatalities were analyzed. Whereas high antibody levels against gB could be detected in sera of multiple EEHV-HD fatalities, all fatalities had low antibody levels against gH/gL of the EEHV (sub)species they succumbed to. Overall, our data indicate that (sub)species-specific gH/gL ELISAs may be used to identify animals at risk of developing EEHV-HD upon infection with a particular EEHV (sub)species.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Hoornweg, T. E., Schaftenaar, W., Rutten, V., de Haan, C. A. M.. 2023-06-16. Low gH/gL (sub)species-specific antibody levels indicate elephants at risk of fatal elephant endotheliotropic herpesvirus hemorrhagic disease. https://doi.org/10.1101/2023.06.15.545196

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

A population-scale landscape of the subgingival microbiome reveals divergent routes to periodontal dysbiosis

Periodontitis is an archetypical mucosal inflammatory disease in which microbiome dysbiosis at the tooth-epithelial interface interacts with host genetic and behavioral risk factors to drive immune-mediated tissue destruction. Although subgingival microbiome compositional shifts are thought to parallel disease severity, microbiome variation at the population-level and its relationship to periodontal clinical phenotypes and disease-modifying factors remain poorly defined. Here, we use unsupervised manifold learning to map the compositional landscape of the subgingival microbiome in 1,355 adults spanning periodontal health to severe periodontitis. We identified eight latent microbiome states organized along a branching continuum from eubiosis to dysbiosis. An intermediate microbial configuration marked ecological destabilization and bifurcation into two distinct periodontitis-associated dysbiotic trajectories, distinguished by links to gingival inflammation and smoking. Although the microbiome trajectories broadly tracked periodontal destruction, a minority of individuals showed discordant microbiome-clinical phenotypes, with some individuals with periodontitis retaining otherwise eubiotic microbiomes enriched for low-abundance pathobionts, while some cases of health or mild disease had highly dysbiotic communities, suggesting distinct host susceptibility. Together, these findings define a population-scale ecological landscape of the subgingival microbiome, reveal divergent trajectories to periodontal dysbiosis, and highlight heterogeneity in the relationship between microbial community structure and clinical disease expression.

microbiology↗

The iron-binding siderophore enterobactin is required for the response of multi-drug resistant Klebsiella pneumoniae to zinc limitation

To persist during infection Klebsiella pneumoniae must overcome nutrient iron and zinc limitation imposed by the host immune system through a process called nutritional immunity. Secreted small molecule siderophores are a major virulence determinant of Klebsiella pneumoniae pathogenesis and are presumed to overcome nutritional immunity by binding iron for bacterial acquisition. In this work, we set out to identify how a multi-drug resistant K. pneumoniae grows in zinc limited environments. Using unbiased transcriptomics, proteomics, and an arrayed transposon screen, we identified that synthesis and uptake of the siderophore enterobactin is required to allow for growth in low zinc conditions. Iron-specific chelators did not replicate this phenotype and addition of supplemental iron through heme in growth media could not complement severe growth defects of enterobactin mutant K. pneumoniae experiencing zinc limitation. Finally, zinc starvation induced enterobactin production independent of the canonical zinc uptake regulator (Zur) transcription factor suggesting an unidentified regulatory mechanism by which Gram-negative pathogens may respond to zinc stress. Together, these studies expand the role of enterobactin beyond iron regulation and highlight a previously unreported link between iron and zinc homeostasis in Klebsiella pneumoniae.

microbiology↗

A microbiota-derived protease links phage susceptibility to host epithelial responses

Bacteriophages are major ecological drivers of gut microbial ecology, yet whether bacterial mechanisms that determine phage susceptibility have consequences for the mammalian host remains poorly understood. Here, we identify dipeptidyl peptidase 11 (Dpp11a), the predominant active serine protease of the prevalent gut commensal Phocaeicola vulgatus, as an unexpected bacterial defence factor. Dpp11a protects against environmental proteases and confers resistance to bacteriophage infection. Metatranscriptomic analyses further reveal increased expression of both dpp11a and P. vulgatus-associated phage transcripts in ulcerative colitis stool samples, indicating that both components of this interaction are transcriptionally active in disease-associated human microbiomes. Using the microfluidic gut-on-a-chip co-culture model HuMiX, we show that the absence of Dpp11 is accompanied by altered epithelial tight-junction remodelling during phage-bacterial infection. Together, our findings reveal that the consequences of bacterial phage defence can extend beyond phage-bacterium interactions to the mammalian epithelium.

microbiology↗