Brucella melitensis biovar 1 isolation in a captive wildlife population in the United Arab Emirates. First isolation in the scimitar-horned Oryx (Oryx dammah)

In 2013, Brucella melitensis biovar 1 was recovered from the stomach contents of a scimitar-horned Oryx - SHO (Oryx dammah) aborted foetus, and from the articular fluid of a sand gazelle (Gazella marica) in a captive wildlife collection near Abu Dhabi, United Arab Emirates. Other evidence of exposure to the pathogen was collected through serological testing (Rose Bengal test) and B. melitensis-specific PCR of samples from captive wildlife kept in six different enclosures. A Multiple Locus Variable Number of Tandem Repeats (VNTR) Analysis (MLVA) using 15 markers showed that the two strains isolated in animals kept in enclosures, located 1300 m apart from each other, shared an identical genotype. The phylogenetic analysis of MLVA-15 profiles retrieved from the public database suggested that these strains belong to the African clade, clustering regionally in the UAE, Oman and Qatar. This is the first confirmed case of B. melitensis in a SHO, an African antelope extinct in the wild and warrants further investigation

Contribution to the wildlife infectious disease risk analysis associated with the reintroduction of the scimitar-horned oryx (Oryx dammah) from the United Arab Emirates to Chad

The reintroduction of the scimitar-horned oryx (Oryx dammah) (SHO) from the United Arab Emirates to Chad provides a unique opportunity for in-depth exploration of various aspects related to the ecological, environmental, and health dynamics associated with this reintroduction process. Prompted by the global decline in biodiversity, this endeavour aims to reinstate a native species and mitigate the negative impacts of human activities on ecosystems. The SHO, recognized as a potential keystone species, which might play a pivotal role in shaping ecosystem structure and functioning. The reintroduction initiative not only focuses on the oryx's well-being but also underscores broader implications for ecosystem health, biodiversity, and the harmony between human and environmental interests. However, the reintroduction process introduces inherent risks, particularly concerning the potential for pathogen pollution and the release of zoonotic pathogens. The increased interaction between the oryx, other wildlife, livestock, and human populations elevates the risk of disease transmission. This necessitates a systematic risk assessment, providing insights to inform strategies for mitigating the potential impacts of disease emergence on both wildlife, livestock, and human health. Brucellosis poses a significant zoonotic risk, with the first confirmed outbreak in SHO described in article 1. Serological testing revealed a high seroprevalence rate, with females and older individuals showing higher probabilities of being seropositive in article 2. In article 6, a controlled trial administering the Rev.1 vaccine demonstrated safety, with both subcutaneous and conjunctival routes eliciting long-term cellular responses. However, the conjunctival route exhibited a shorter humoral response. Furthermore, the presence of Bluetongue virus genome in seronegative oryx post-transport highlights risks associated with translocation in appendix 1, necessitating pre-import risk assessment for wild ruminant species susceptible to orbiviruses not only in the country of destination but also where transit happens. Foot-and-mouth disease outbreaks underscore the susceptibility of SHO to this economically impactful disease in article 3, emphasizing the need for robust surveillance and control measures. Contagious caprine pleuropneumonia outbreaks further demonstrate the susceptibility of related wildlife species in article 4 and highlight transmission dynamics previously undocumented in article 5. Our findings provide valuable insights into the epidemiology of pathogens circulating in the United Arab Emirates, informing risk management strategies for the reintroduction of the SHO. Through comprehensive risk assessment and transparent communication, stakeholders play a pivotal role in shaping the success of this conservation endeavour

Presence of IgG antibodies is not a reliable marker of Toxoplasma gondii infection in feral mice

The single-celled parasite Toxoplasma gondii uses mice as a vector to reach its definitive host, the cat, where it can accomplish its sexual reproduction and produce oocysts, which will contaminate the environment. In this study, we have captured 103 feral house mice (Mus musculus) on Kangaroo Island, Australia. We have measured the level of exposure to T.gondii serologically with the Modified Agglutination Test and conjointly with a T.gondii B1 gene PCR. We have included stringent quality control steps in the molecular analysis to reduce the risk of false positivity and false negativity. Our results indicated a low seroprevalence of 0.97%, 95%CI [-0.36; 0.58] associated with the detection of T.gondii genetic material in 51.46%, 95%CI [41.93, 60.88] of mice brains. Neither sex nor mice body weight had an effect on the PCR outcome. We postulate that both the transmission route, horizontal or vertical, and natural selection processes could lead to this discordance which has been observed elsewhere in wild mice. The question of the biological mechanisms allowing the chronic infection of wild mice in the absence of a measurable humoral immune response remains. Our findings indicate that serological studies should not be used to measure the level of exposure to T.gondii in feral house mice

Brucella melitensis biovar 1 isolation in a captive wildlife population in the United Arab Emirates. First isolation in the scimitar-horned Oryx (Oryx dammah).

peer reviewedIn 2013, Brucella melitensis biovar 1 was recovered from the stomach contents of a scimitar-horned Oryx - SHO (Oryx dammah) aborted foetus, and from the articular fluid of a sand gazelle (Gazella marica) in a captive wildlife collection near Abu Dhabi, United Arab Emirates. Other evidence of exposure to the pathogen was collected through serological testing (Rose Bengal test) and B. melitensis-specific PCR of samples from captive wildlife kept in six different enclosures. A Multiple Locus Variable Number of Tandem Repeats (VNTR) Analysis (MLVA) using 15 markers showed that the two strains isolated in animals kept in enclosures, located 1300 m apart from each other, shared an identical genotype. The phylogenetic analysis of MLVA-15 profiles retrieved from the public database suggested that these strains belong to the African clade, clustering regionally in the UAE, Oman and Qatar. This is the first confirmed case of B. melitensis in a SHO, an African antelope extinct in the wild and warrants further investigation

Orbivirus screening on dried blood spots from captive oryx in United Arab Emirates stresses the importance of pre-import measures

Objective: Following reintroduction and conservation programs of the Arabian oryx (Oryx leucoryx) and the scimitar horned oryx (SHO, Oryx dammah) in the United Arab Emirates (UAE), import of animals from wild game ranches in the United States of America (USA) is not uncommon. Bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) are orbiviruses that are the causative agents of bluetongue disease (BT) and epizootic hemorrhagic disease (EHD), respectively. BTV and EHDV are endemic in the UAE and the USA. Sheep and some wild ruminant species are usually severely affected by BT whereas EHD mostly affects wild animals and sometimes cattle. The objective of this study was to estimate the prevalence of these orbiviruses in Arabian and SHO from captive herds in the UAE using serology and molecular virology. Dry blood spot sampling for orbivirus screening is also discussed. Methods: A total of 175 SHO and 16 Arabian oryx were sampled. The latters were imported from Texas (USA) two weeks before sampling. All sampled animals belonged to captive herds spread over the Al Wathba area. For biosecurity reasons and to simplify blood storage, elutes from dried blood spot were used for serological and virological tests. Drops of about 80 µl of blood were dispensed on Whatman protein saver cards, and then allowed to dry in the dark at room temperature for 48 hours. Blood spots were punched out in paper discs with a 6 mm diameter punch and diluted in 250 µl PBS and Tween 20 0.05%. Eluted samples were incubated overnight at room temperature and then used immediately or stored at -80°C. To assess the most suitable ELISA kit to detect anti-BTV antibodies from the oryx discs, similar discs were prepared using blood issued from BTV seropositive and viremic as well as seronegative and non-viremic cattle. Elutes from discs with dried-blood from cattle were tested by BTV competitive ELISA (cELISA), sandwich ELISA (sELISA) and indirect ELISA (iELISA) and compared to cELISA performed directly on the serum of the same animals. iELISA on cattle paper discs gave the best correspondence with cELISA on cattle serum and was therefore used to test the oryx paper discs. Subsequently oryx paper discs were tested to detect antibodies against EHDV by cELISA. All the paper discs elutes from Arabian oryx and ELISA positive elutes from SHO were also tested by pan-BTV RTqPCR targeting a fragment of BTV segment 5 and detecting all BTV serotypes. Serotype specific end-point RT-PCR targeting a fragment of segment 2 of BTV2, BTV8, BTV10, BTV11, BTV13 and BTV17 were performed on pan-BTV positive samples. Results: Three out of 175 SHO and eight out of 16 Arabian oryx were found BTV seropositive by iELISA. None of the animals could be found seropositive against EHDV. BTV genome was detected in 1/3 seropositive SHO and in 5/16 of the Arabian oryx, amongst those 2/5 were seronegative. Overall Cq values were high (33-39). End point PCR failed to detect positive samples for any of the tested serotypes. Conclusion: BTV seroprevalence and RNA detection in SHO was very limited. By contrast BTV could be demonstrated in 5/16 imported Arabian oryx by molecular virology and in 8/16 by serology. The sampling was realized two weeks after the animals arrived in UAE and some oryx were viremic and seronegative, possibly suggesting a recent infection. Among the local SHO a low BTV seroprevalence was observed (3/175) and no animals were found positive to EHDV. This result was quite surprising because previous studies showed a higher BTV seroprevalence in domestic and wild ruminants of the Arabian Peninsula with wide local variations. In addition, dried blood spot testing has been demonstrated being a convenient and reliable method of sampling when storage conditions are hazardous. BTV serotypes could not be determined by end-point RT-PCR. At least 15 different BTV serotypes were reported in the USA and at least 10 in the Middle East, thus the oryx could be infected by a serotype not tested so far. Since RTqPCR positive values were high, the sensitivity of end-point RT-PCR might be insufficient to detect BTV out of eluted blood spots. Additional testing will be performed to identify the virus on the serotype level and therefore provide new insights to clarify the origin of the infection of the oryx. These results stress the need for pre-import risk assessment, precaution and implementation of biosecurity measures when considering translocation of wild ruminant species susceptible to BTV and EHDV

Note on the Siphonaptera of the Emirate of Ras Al Khaimah: description of Nosopsyllus (Gerbillophilus) jabeljaisensis n. sp. (Siphonaptera, Ceratophyllidae, Ceratophyllinae)

peer reviewedTwenty two fleas collected during Acomys dimidiatus et Gerbillus dasyurus trapping in the montains of Ras Al Khaimah in the United Arab Emirates were identified as belonging to two species. A new taxon is descrided in the genus Nosopsyllus © 2016 Société entomologique de France

Brucellosis seroprevalence in captive scimitar-horned oryx (Oryx dammah) in the United Arab Emirates and associated risk factors

Background: The scimitar‐horned oryx (Oryx dammah) (SHO) is a large African antelope that became extinct in the wild just over two decades ago. Conservation of the species is of prime importance, but it might face pathogen stressors. Methods and principal findings: Brucella melitensis biovar 1 was previously confirmed in a high‐density captive population of SHO held in Abu‐Dhabi emirate. The infection reached 67.0 % (95 % CI: 64.0–70.0) individual seroprevalence (n = 959) during testing performed between January 2013 and January 2015. A model based on a multivariable logistic regression analysis showed that the seroprevalence ranged from 51.2 (95 % CI: 39.6–62.7) to 86.9 % (95 % CI: 82.4–91.4) between six different enclosures, and probability of being seropositive was 1.83 (95 % CI: 1.32–2.55) higher in females than in males, 3.09 (95 % CI: 1.66–5.91) and 9.35 (95 % CI: 4.66–19.44) higher in subadults and adults than in juveniles, respectively. The three serological tests used in this study (Rose Bengal Test, lateral flow assay and in‐house i‐ELISA) had a perfect or near‐perfect agreement (Cohen’s Kappa coefficient >=0.97). Recurrent high seroprevalence in time and congruence of results from three different serological tests point toward a persistent B. melitensis infection in a high‐density captive SHO population. Conclusion and significance Testing strategy (Bengal Test, lateral flow assay or in‐house i‐ELISA) has no effect on the estimation of the brucellosis seroprevalence in SHO permitting the selection of a practical test. We call for an evidence‐based control program, and Brucella vaccine efficacy and innocuity studies in this endangered species

Unexpected field observations and transmission dynamics of contagious caprine pleuropneumonia in a sand gazelle herd

Contagious caprine pleuropneumonia (CCPP), caused by Mycoplasma capricolum subsp. capripneumoniae, has long been considered a goat-specific disease. Since 2007 there has been growing evidence that this disease can affect wild ungulates either kept in captivity or in the wild. In 2013, a large collection of sand gazelles (Gazella marica) held in the United Arab Emirates suffered heavy losses due to a CCPP epizootic confirmed by PCR and isolation. Animals displayed typical lesions, with unilateral pneumonia and profuse pleurisy. An initial antibiotic treatment consisting of tylosin administered in drinking water did not improve the animals’ condition and vaccination failed to stop the spread to contiguous pens. A treatment with tetracycline mixed in feed pellets finally succeeded to stop the evolution of the disease. A subsequent vaccine trial, performed on naïve animals, showed that only a reference CCPP vaccine produced according to OIE standards induced a sero-conversion by CCPP competition ELISA, while the commercially available vaccines did not. A SEIRD compartment transmission model was developed to better understand the dynamics of the disease. The parameters were initially set as per expert opinion and then adjusted to fit the observed mortality data. The basic reproductive number R0 was estimated to be between 2.3–2.7, while the final mortality rate reached up to 70% in some pens. Transmission of infectious droplets from an external source, through a distance of at least the 50 m separating the pens from the perimeter fence, remains the most plausible explanation for the contamination of this stock of gazelles. © 2018 Elsevier B.V