42 research outputs found
Low gH/gL (Sub)Species-Specific Antibody Levels Indicate Elephants at Risk of Fatal Elephant Endotheliotropic Herpesvirus Hemorrhagic Disease
Elephant endotheliotropic herpesviruses (EEHVs), of which eleven (sub)species are currently distinguished, infect either Asian (Elephas maximus) or African elephants (Loxodonta species). While all adult elephants are latently infected with at least one EEHV (sub)species, young elephants, specifically those with low to non-detectable EEHV-specific antibody levels, may develop fatal hemorrhagic disease (EEHV-HD) upon infection. However, animals with high antibody levels against EEHV(1A) gB, an immunodominant antigen recognized by antibodies elicited against multiple (sub)species, may also occasionally succumb to EEHV-HD. To better define which animals are at risk of EEHV-HD, gB and gH/gL ELISAs were developed for each of the Asian elephant EEHV subspecies and assessed using 396 sera from 164 Asian elephants from European zoos. Antibody levels measured against gB of different (sub)species correlated strongly with one another, suggesting high cross-reactivity. Antibody levels against gH/gL of different subspecies were far less correlated and allowed differentiation between these (sub)species. Importantly, while high gB-specific antibody levels were detected in the sera of several EEHV-HD fatalities, all fatalities (n = 23) had low antibody levels against gH/gL of the subspecies causing disease. Overall, our data indicate that (sub)species-specific gH/gL ELISAs can be used to identify animals at risk of EEHV-HD when infected with a particular EEHV (sub)species
Low gH/gL (sub)species-specific antibody levels indicate elephants at risk of fatal elephant endotheliotropic herpesvirus hemorrhagic disease
DATA AVAILABILITY STATEMENT : The data supporting the findings of this study are available from the corresponding authors upon reasonable request.Elephant endotheliotropic herpesviruses (EEHVs), of which eleven (sub)species are currently distinguished, infect either Asian (Elephas maximus) or African elephants (Loxodonta species). While all adult elephants are latently infected with at least one EEHV (sub)species, young elephants, specifically those with low to non-detectable EEHV-specific antibody levels, may develop fatal hemorrhagic disease (EEHV-HD) upon infection. However, animals with high antibody levels against EEHV(1A) gB, an immunodominant antigen recognized by antibodies elicited against multiple (sub)species, may also occasionally succumb to EEHV-HD. To better define which animals are at risk of EEHV-HD, gB and gH/gL ELISAs were developed for each of the Asian elephant EEHV subspecies and assessed using 396 sera from 164 Asian elephants from European zoos. Antibody levels measured against gB of different (sub)species correlated strongly with one another, suggesting high cross-reactivity. Antibody levels against gH/gL of different subspecies were far less correlated and allowed differentiation between these (sub)species. Importantly, while high gB-specific antibody levels were detected in the sera of several EEHV-HD fatalities, all fatalities (n = 23) had low antibody levels against gH/gL of the subspecies causing disease. Overall, our data indicate that (sub)species-specific gH/gL ELISAs can be used to identify animals at risk of EEHV-HD when infected with a particular EEHV (sub)species.Named Fund Friends of VetMed.https://www.mdpi.com/journal/viruseshj2024Veterinary Tropical DiseasesSDG-03:Good heatlh and well-bein
High seroprevalence of human herpesviruses in HIV-infected individuals attending primary healthcare facilities in rural South Africa
Seroprevalence data of human herpesviruses (HHVs) are limited for sub-Saharan Africa. These are important to provide an indication of potential burden of HHV-related disease, in particular in human immunodeficiency virus (HIV)-infected individuals who are known to be at increased risk of these conditions in the Western world. In this cross-sectional study among 405 HIV-infected and antiretroviral therapy naïve individuals in rural South Africa the seroprevalence of HHVs was: herpes simplex virus type 1 (HSV-1) (98%), herpes simplex virus type 2 (HSV-2) (87%), varicella zoster virus (VZV) (89%), and 100% for both Epstein-Barr virus (EBV) and cytomegalovirus (CMV). Independent factors associated with VZV seropositivity were low educational status and having children. Lack of in-house access to drinking water was independently associated with positive HSV-1 serostatus, whereas Shangaan ethnicity was associated with HSV-2 seropositivity. Increasing age was associated with higher IgG titres to both EBV and CMV, whereas CD4 cell count was negatively associated with EBV and CMV IgG titres. Moreover, IgG titres of HSV-1 and 2, VZV and CMV, and CMV and EBV were positively correlated. The high HHV seroprevalence emphasises the importance of awareness of these viral infections in HIV-infected individuals in South Africa
Clinical and corneal microbial profile of infectious keratitis in a high HIV prevalence setting in rural South Africa
The purpose of this investigation was to determine the clinical and corneal microbial profile of infectious keratitis in a high human immunodeficiency virus (HIV) prevalence setting in rural South Africa. Data in this cross-sectional study were collected from patients presenting with symptoms of infectious keratitis (n = 46) at the ophthalmology outpatient department of three hospitals in rural South Africa. Corneal swabs were tested for herpes simplex virus type 1 (HSV-1) and 2 (HSV-2), varicella zoster virus (VZV) and adenovirus DNA by real-time polymerase chain reaction (PCR
Triazole Fungicides Can Induce Cross-Resistance to Medical Triazoles in Aspergillus fumigatus
Contains fulltext :
103858.pdf (publisher's version ) (Open Access)BACKGROUND: Azoles play an important role in the management of Aspergillus diseases. Azole resistance is an emerging global problem in Aspergillus fumigatus, and may develop through patient therapy. In addition, an environmental route of resistance development has been suggested through exposure to 14alpha-demethylase inhibitors (DMIs). The main resistance mechanism associated with this putative fungicide-driven route is a combination of alterations in the Cyp51A-gene (TR(34)/L98H). We investigated if TR(34)/L98H could have developed through exposure to DMIs. METHODS AND FINDINGS: Thirty-one compounds that have been authorized for use as fungicides, herbicides, herbicide safeners and plant growth regulators in The Netherlands between 1970 and 2005, were investigated for cross-resistance to medical triazoles. Furthermore, CYP51-protein homology modeling and molecule alignment studies were performed to identify similarity in molecule structure and docking modes. Five triazole DMIs, propiconazole, bromuconazole, tebuconazole, epoxiconazole and difenoconazole, showed very similar molecule structures to the medical triazoles and adopted similar poses while docking the protein. These DMIs also showed the greatest cross-resistance and, importantly, were authorized for use between 1990 and 1996, directly preceding the recovery of the first clinical TR(34)/L98H isolate in 1998. Through microsatellite genotyping of TR(34)/L98H isolates we were able to calculate that the first isolate would have arisen in 1997, confirming the results of the abovementioned experiments. Finally, we performed induction experiments to investigate if TR(34)/L98H could be induced under laboratory conditions. One isolate evolved from two copies of the tandem repeat to three, indicating that fungicide pressure can indeed result in these genomic changes. CONCLUSIONS: Our findings support a fungicide-driven route of TR(34)/L98H development in A. fumigatus. Similar molecule structure characteristics of five triazole DMIs and the three medical triazoles appear the underlying mechanism of cross resistance development. Our findings have major implications for the assessment of health risks associated with the use of triazole DMIs
Effect of calcium and cholecalciferol supplementation on several parameters of calcium status in plasma and urine of captive Asian (Elephas maximus) and African elephants (Loxodonta Africana)
The aim of the current study was to assess the effect of oral calcium and cholecalciferol
supplementation on several parameters of calcium status in plasma and urine of captive Asian (Elephas maximus;
n = 10) and African elephants (Loxodonta africana; n = 6) and to detect potential species differences. Calcium and
cholecalciferol supplementation were investigated in a feeding trial using a crossover design consisting of five
periods of 28 days each in summer. From days 28–56 (period 2), elephants were fed the Ca-supplemented diet and
from days 84–112, elephants were fed the cholecalciferol-supplemented diet (period 4). The control diet was fed
during the other periods and was based on their regular ration, and the study was repeated similarly during winter.
Periods 1, 3, and 5 were regarded as washout periods. This study revealed species-specific differences with
reference to calcium and cholecalciferol supplementation. Asian elephants showed a significant increase in mean
plasma total calcium concentration following calcium supplementation during summer, suggesting summerassociated
subclinical hypocalcemia in Western Europe. During winter, no effect was seen after oral calcium
supplementation, but a significant increase was seen both in mean plasma, total, and ionized calcium
concentrations after cholecalciferol supplementation in Asian elephants. In contrast, evidence of subclinical
hypocalcemia could be demonstrated neither in summer nor in winter in African elephants, although 28 days of
cholecalciferol supplementation during winter reversed the decrease in plasma 1,25(OH)2-cholecalciferol and was
followed by a significant increase in mean plasma total calcium concentration. Preliminary findings indicate that
the advisable permanent daily intake for calcium in Asian elephants and cholecalciferol in both elephant species at
least during winter might be higher than current guidelines. It is strongly recommended to monitor blood calcium
concentrations and, if available, blood parathyroid hormone levels to adjust the nutritional supplementation for
each individual elephant.http://zoowildlifejournal.com/am201
EEHV1A glycoprotein B subunit vaccine elicits humoral and cell-mediated immune responses in mice
Asian elephants are an endangered species facing many threats, including severe hemorrhagic disease (HD) caused by the elephant endotheliotropic herpesvirus (EEHV). EEHV-HD is the leading cause of death in captive juvenile Asian elephants in North America and Europe, and also affects elephants in their natural range countries. Significant challenges exist for successful treatment of EEHV-HD, which include timely recognition of disease onset and limited availability of highly effective treatment options. To address this problem, our goal is to prevent lethal disease in young elephants by developing a vaccine that elicits robust and durable humoral and cell-mediated immunity against EEHV. EEHV glycoprotein B (gB) is a major target for cellular and humoral immunity in elephants previously exposed to EEHV. Therefore, we generated a vaccine containing recombinant EEHV1A gB together with a liposome formulated TLR-4 and saponin combination adjuvant (SLA-LSQ). CD-1 mice that received one or two vaccinations with the vaccine elicited significant anti-gB antibody and polyfunctional CD4+ and CD8+ T cell responses, while no adverse effects of vaccination were observed. Overall, our findings demonstrate that an adjuvanted gB protein subunit vaccine stimulates robust humoral and cell-mediated immune responses and supports its potential use in elephants
A novel antigen capture ELISA for the specific detection of IgG antibodies to elephant endotheliotropic herpes virus
BACKGROUND
Elephants are classified as critically endangered animals by the International Union for Conservation of Species (IUCN). Elephant endotheliotropic herpesvirus (EEHV) poses a large threat to breeding programs of captive Asian elephants by causing fatal haemorrhagic disease. EEHV infection is detected by PCR in samples from both clinically ill and asymptomatic elephants with an active infection, whereas latent carriers can be distinguished exclusively via serological assays. To date, identification of latent carriers has been challenging, since there are no serological assays capable of detecting seropositive elephants.
RESULTS
Here we describe a novel ELISA that specifically detects EEHV antibodies circulating in Asian elephant plasma/serum. Approximately 80 % of PCR positive elephants display EEHV-specific antibodies. Monitoring three Asian elephant herds from European zoos revealed that the serostatus of elephants within a herd varied from non-detectable to high titers. The antibody titers showed typical herpes-like rise-and-fall patterns in time which occur in all seropositive animals in the herd more or less simultaneously.
CONCLUSIONS
This study shows that the developed ELISA is suitable to detect antibodies specific to EEHV. It allows study of EEHV seroprevalence in Asian elephants. Results confirm that EEHV prevalence among Asian elephants (whether captive-born or wild-caught) is high
EEHV1A glycoprotein B subunit vaccine elicits humoral and cell-mediated immune responses in mice
DATA AVAILABILITY : Data will be made available on request.Asian elephants are an endangered species facing many threats, including severe hemorrhagic disease
(HD) caused by the elephant endotheliotropic herpesvirus (EEHV). EEHV-HD is the leading cause of death
in captive juvenile Asian elephants in North America and Europe, and also affects elephants in their natural
range countries. Significant challenges exist for successful treatment of EEHV-HD, which include
timely recognition of disease onset and limited availability of highly effective treatment options. To
address this problem, our goal is to prevent lethal disease in young elephants by developing a vaccine
that elicits robust and durable humoral and cell-mediated immunity against EEHV. EEHV glycoprotein
B (gB) is a major target for cellular and humoral immunity in elephants previously exposed to EEHV.
Therefore, we generated a vaccine containing recombinant EEHV1A gB together with a liposome formulated
TLR-4 and saponin combination adjuvant (SLA-LSQ). CD-1 mice that received one or two vaccinations
with the vaccine elicited significant anti-gB antibody and polyfunctional CD4+ and CD8+ T cell
responses, while no adverse effects of vaccination were observed. Overall, our findings demonstrate that
an adjuvanted gB protein subunit vaccine stimulates robust humoral and cell-mediated immune
responses and supports its potential use in elephants.The Cytometry and Cell Sorting Core at Baylor College of Medicine with funding from the CPRIT Core Facility Support Award, the NIH, the International Elephant Foundation (IEF) and Houston Zoo and funds acquired via Named Fund Friends of VetMed to the Utrecht University EEHV research group.http://www.elsevier.com/locate/vaccineam2023Veterinary Tropical Disease
Young elephants in a large herd maintain high levels of elephant endotheliotropic herpesvirus-specific antibodies and do not succumb to fatal haemorrhagic disease
Elephant endotheliotropic herpesviruses (EEHVs) have co-existed with elephants for millions of years, yet may cause fatal haemorrhagic disease (EEHV-HD), typically in elephants between 1 and 10 years of age. EEHV is omnipresent in (sub)adult elephants, and young elephants with low EEHV-specific antibody levels are at risk for EEHV-HD, suggesting that fatal disease may occur due to an insufficiently controlled primary infection. To further address this hypothesis, sera of three large elephant cohorts were subjected to a multiple EEHV species ELISA: (I) 96 Asian elephants between 0 and 57 years, including 13 EEHV-HD fatalities, from European zoo herds typically sized five to six elephants, (II) a herd of 64 orphaned elephants aged 0–15 years at the Elephant Transit Home in Sri Lanka and (III) 31 elephants aged 8–63 years, part of a large herd of 93 elephants at Pinnawala Elephant Orphanage, Sri Lanka. All Sri Lankan elephants showed high EEHV-specific antibody levels regardless of their age. While antibody levels of most European zoo elephants were comparable to those of Sri Lankan elephants, the average antibody level of the European juveniles (1–5 years of age) was significantly lower than those of age-matched Sri Lankan individuals. Moreover, the European juveniles showed a gradual decrease between 1 and 4 years of age, to be attributed to waning maternal antibodies. Maintenance of high levels of antibodies in spite of waning maternal antibodies in young Sri Lankan elephants is likely due to the larger herd size that increases the likelihood of contact with EEHV-shedding elephants. Together with the observation that low levels of EEHV-specific antibodies correlate with increased numbers of EEHV-HD fatalities, these results suggest that infection in presence of high maternal antibody levels may protect calves from developing EEHV-HD, while at the same time activating an immune response protective in future encounters with this virus.http://wileyonlinelibrary.com/journal/tbedhj2022Veterinary Tropical Disease