Brucellosis in camels

Brucella spondylodiscitis that affected both cervical and lumbar spines: a rare case report from Syria

Introduction and importance

Brucellosis, the most common microbial zoonotic disease in the world, is endemic in both industrialized and underdeveloped countries. Between 2 and 53% of patients with brucellosis, patients develop spondylitis, and people between the ages of 50 and 60 are the most commonly affected. It mostly affects the lumbar vertebrae (L4 and L5 in particular) and the thoracic vertebrae.

Case presentation

A 52-year-old patient was brought to the neurological clinic after complaining of lower back discomfort, reduced mobility, and lower extremity weakness for 6 weeks. Both the cervical and lumbar columns were the sites of the specific discomfort. MRI showed cervical and lumbar discitis.

Clinical discussion

A high titre of anti-brucella antibodies was found by serology testing. He was treated with oral doxycycline (100 mg, two times daily), rifampicin (900 mg) orally once daily, and gentamicin (400 mg) once daily. The patient had massive improvement after 3 months of treatment.

Conclusions

This case should serve as a reminder to healthcare providers to keep a high index of suspicion for uncommon infections, including Brucella species, in patients exhibiting discitis symptoms, especially when traditional microbiological gram stain and culture are negative.

Bayesian true prevalence estimation of brucellosis in sheep, goats, cattle and camels in southeast regions of Iran

AIMS AND METHODS

Brucellosis is worldwide one of the most prevalent zoonotic diseases with serious public health hazard affecting domestic livestock and causing economic losses. Objective of this study is to estimate the true prevalence of brucellosis in livestock, specifically cattle, sheep, goats and camels, using a novel Bayesian latent class model, adjusting for the imperfect sensitivity and specificity of the applied tests, where the second test was restricted only to first test-positive samples.

RESULTS

Brucellosis seems more prevalent in goats and sheep, while the posterior medians and 95% probability intervals (95% PI) for the average true prevalence for sheep, goats, cattle and camels are 18% (4%-43%), 19% (7%-37%), 16% (5%-34%) and 18% (1%-48%) respectively.

CONCLUSIONS

The study results indicate that brucellosis is highly endemic in Iran and crucial steps are needed to control and raise awareness about the high public health concern of the disease.

Serological and molecular survey of brucellosis and chlamydiosis in dromedary camels from Tunisia

The present sero-epidemiological survey was designed and conducted to scrutinize the current status of camel-related brucellosis and chlamydiosis in Tunisia. Whole blood and serum samples were collected from 470 dromedaries (Camelus dromedarius) from eight different Tunisian governorates. Serum samples were subjected to indirect enzyme-linked immunosorbent assay (iELISA). The detection of Brucella and Chlamydia DNA was performed using conventional PCR targeting the bcsp-31 and 16 S rRNA gene, respectively. Overall, 10/470(2.12%) and 27/470 (5.75%) camels were revealed seropositive to Brucella and Chlamydia, respectively. Multivariate logistic regression analysis showed different risk factors associated with these infections. Meaningful high rates of seropositivity of brucellosis (9.5%; p = 0.000; OR=64.193) and chlamydiosis (22.6%; p = 0.000; OR=42.860) were noted among camels showing previous abortions in particular for aged females. Besides, Chlamydia seropositivity is significantly important during winter (12.5%; p = 0.009; OR= 27.533), and in camels raised in small farms (11.4%, p = 0.000, OR=86.052). Molecular analysis revealed no positivity from all analyzed blood samples. These findings indicate the involvement of camels in the epidemiology of these abortive infectious diseases. This raises awareness and serious public health concern for infectious camel diseases in order to develop further diagnostic improvements and effective control strategies.

Microbial Risks Caused by Livestock Excrement: Current Research Status and Prospects

Livestock excrement is a major pollutant yielded from husbandry and it has been constantly imported into various related environments. Livestock excrement comprises a variety of microorganisms including certain units with health risks and these microorganisms are transferred synchronically during the management and utilization processes of livestock excrement. The livestock excrement microbiome is extensively affecting the microbiome of humans and the relevant environments and it could be altered by related environmental factors as well. The zoonotic microorganisms, extremely zoonotic pathogens, and antibiotic-resistant microorganisms are posing threats to human health and environmental safety. In this review, we highlight the main feature of the microbiome of livestock excrement and elucidate the composition and structure of the repertoire of microbes, how these microbes transfer from different spots, and they then affect the microbiomes of related habitants as a whole. Overall, the environmental problems caused by the microbiome of livestock excrement and the potential risks it may cause are summarized from the microbial perspective and the strategies for prediction, prevention, and management are discussed so as to provide a reference for further studies regarding potential microbial risks of livestock excrement microbes.

Molecular Detection and Associated Risk Factors of Brucella melitensis in Aborted Sheep and Goats in Duhok Province, Iraq

Brucellosis in sheep and goats has a significant economic and zoonotic impact on the livestock population of Duhok province, Iraq. A total of 681 blood samples from aborted sheep and goats were collected from different flocks in seven districts of Duhok and tested using real-time polymerase chain reaction (RT-PCR). Logistic regression was used for the analysis of the potential risk factors associated with RT-PCR positivity. Results revealed an overall prevalence of 35.45% (CI = 2.57) and 23.8% 18 (CI = 0.44) in sheep and goats, respectively. A statistically significant (p = 0.004) difference in prevalence was found between the two species. RT-PCR detected more positive cases in older-aged animals (OR = 0.7164; p = 0.073). A significant difference was found in RT-PCR positivity in relation to different risk factors, including body condition, treatment taken, and abortion frequency (<0.001). The phylogenetic tree based on the 16S rRNA gene indicated that the isolates belonged to B. melitensis and shared a common ancestor and were genetically related to the United States of America (USA), Greece, China, and Nigeria. This study demonstrates that brucellosis is widely prevalent in the study regions. Therefore, the study suggests the implementation of preventive control measures for brucellosis.

An Epidemiological Study of Brucellosis in Different Animal Species from the Al-Qassim Region, Saudi Arabia

Brucellosis is a zoonotic bacterial illness that affects humans and a variety of domestic animals, especially ruminants. It is mostly transmitted through the consumption of contaminated drinks, foods, undercooked meat, or unpasteurized milk or contact with infected animals. Therefore, the present study aimed to investigate the seroprevalence of brucellosis in camels, sheep, and goat herds in the Qassim region, Saudi Arabia, using commonly used diagnostic serological procedures such as the Rose Bengal test (RBT), complement fixation test (CFT), and enzyme-linked immunosorbent assay (ELISA). The seroprevalence of brucellosis in camels, sheep, and goats was determined in the selected areas using a cross-sectional study design and a total of 690 farm animals of both sexes of different ages from the three animal species (274 camels, 227 sheep, and 189 goats). According to RBT results, 65 sera were positive for brucellosis, including 15 (5.47%) for camels, 32 (14.09%) for sheep, and 18 (9.50%) for goats. CFT and c-ELISA were performed as confirmatory tests on positive samples resulting from RBT. With c-ELISA, 60 serum samples were confirmed positive, in 14 (5.10%), 30 (13.21%), and 16 (8.46%) camels, sheep, and goats, respectively. There were 59 serum samples confirmed as positive for CFT, including 14 (5.11%), 29 (12.77%), and 16 (8.46%) for camels, sheep, and goats, respectively. Overall, the highest seroprevalence of brucellosis was found in sheep while the least was found in camels from the three tests (RBT, c-ELISA, and CFT). The highest seroprevalence of brucellosis was found in sheep while the least seroprevalence was found in camels. There was also a higher seroprevalence of brucellosis among female animals than males as well as among old animals than young animals. The study, thus, demonstrates brucellosis seroprevalence among farm animals (camels, sheep, and goats) and the significance of intervention measures against brucellosis incidence in both humans and animals through the creation of public awareness and other relevant policy measures such as livestock vaccination, effective hygiene management, and adequate quarantine or serological analysis for newly introduced animals.

Serological investigation of plague and brucellosis infection in Marmota himalayana plague foci in the Altun Mountains on the Qinghai-Tibet Plateau

The Altun Mountains are among the most active regions of Marmota himalayana plague foci of the Qinghai-Tibet Plateau where animal plague is prevalent, whereas only three human cases have been found since 1960. Animal husbandry is the main income for the local economy; brucellosis appears sometimes in animals and less often in humans. In this study, a retrospective investigation of plague and brucellosis seroprevalence among humans and animals was conducted to improve prevention and control measures for the two diseases. Animal and human sera were collected for routine surveillance from 2018 to 2021 and screened for plague and brucellosis. Yersinia pestis F1 antibody was preliminarily screened by the colloidal gold method at the monitoring site to identify previous infections with positive serology. Previous plague infection was found in 3.2% (14/432) of the studied human population having close contact with livestock, which indicates evidence of exposure to the Yersinia antigen (dead or live pathogenic materials) in the Altun Mountains. Seroprevalence of brucellosis was higher in camels (6.2%) and sheepdogs (1.8%) than in other livestock such as cattle and sheep, suggesting a possible transmission route from secondary host animals to humans.

European Regulations on Camel Germplasm Movement within the European Union: A Current Framework Based on Safety

Simple Summary

Delegated Regulation (EU) 2020/686 (hereafter Reg. 686) regulates the traceability and animal health for the movement of germinal material of camels within the EU. Given that the camel breeding industry is in a strong phase of growth, an amount of germinal material of terrestrial animals—including those belonging to the Camelidae family—is moved between the member states. The authors performed an analysis of Reg. 686 addressing veterinarians and breeders who want to sell high-quality germinal material or genetically improve their herds.

Abstract

With the aim of developing livestock breeding, the Delegated Regulation (EU) 2020/686 (hereafter referred to as Reg. 686) has taken steps to define traceability and animal health for the movement of germ material within the European Union (EU), including that of camelid species. Despite the economic importance of the camel market and the efforts of the EU to regulate their movements, there are considerable difficulties in the collection of semen and its freezing, limiting the use of artificial insemination in this species. If, on the one hand, there is little diffusion of the camel breeding and, consequently, limited diffusion of animals and germplasm, there will probably be a significant increase over the years. To avoid the spread of emerging diseases—or even those no longer present in Europe—the entry of genetic material from non-EU countries must be strictly monitored. Camels are rarely clinically compliant, but can transfer even fatal diseases to domestic ungulate farms in the EU. Based on these considerations, we conducted a narrative review of the European regulations on this issue, focusing on aspects related to their application in camels.

Animal Brucellosis: Seropositivity rates, Isolation and Molecular Detection in Southern and Central Ethiopia

INTRODUCTION

Brucellosis is a neglected bacterial zoonosis with serious veterinary and public health importance throughout the world. A cross-sectional study on animal brucellosis was conducted aiming to estimate seroprevalence and molecular detection.

METHODS

Blood samples were collected from a total of 4274 individual animals (cattle, small ruminants and camel) from 241 herds/flocks for serology and PCR. Serum samples were tested using multispecies I-ELISA. Blood clots from seropositive animals were also tested for brucellosis via PCR. Additionally, 13 vaginal swab samples were collected from animals (2 from bovine and 11 from small ruminants) with recent abortion history for bacterial isolation and molecular detection.

RESULTS

The overall individual animal and herd level seroprevalence was 3.95% (169/4274) and 18.26% (44/241) respectively. The animal level seroprevalence at species level was 1.58% (47/2982), 8.89% (97/1091) and 12.44% (25/201) in bovine, small ruminants (sheep and goat) and camel, respectively. Herd level seroprevalence were 5.43% (10/184), 52.08% (25/48) and 100% (9/9) in bovine, small ruminant and camel, respectively. The animal level seroprevalence of bovine from intensive and extensive systems was 1.10% (31/2808) and 2.87% (5/174) respectively. Blood clots tested for brucellosis via PCR were negative by RT-PCR. Brucella species was isolated from 6/13 (46.15%) vaginal swab samples cultured on Brucella selective agar, and shown to be B. melitensis using Real-Time PCR.

CONCLUSION

Overall, seropositivity for camels was higher than what has been reported previously. Also, there was a notable difference in this study in cattle seroprevalence when comparing extensive with intensive systems, with the extensive system having much greater seropositivity.

Brucellosis in Ethiopia: A comprehensive review of literature from the year 2000-2020 and the way forward

Brucellosis is a zoonotic disease of considerable economic and public health significance globally. Despite the limited bacteriological evidence, a large number of serological works revealed that it is prevalent both in livestock and humans in Ethiopia. The current comprehensive review was carried out to provide apparent pooled seroprevalence (APS) estimates at individual animal and herd levels in livestock, and identify factors causing variability between studies conducted over the last two decades, show the spatial distribution, as well as summarizes Brucella species reported from livestock. It also provides APS of brucellosis in humans and evaluates the public health awareness of zoonotic brucellosis. In this review, systematic and synthetic review approaches were followed to summarize the available information. For the systematic review and meta-analysis, articles were selected based on predefined criteria. Data extracted from these articles were analyzed using meta-analytical approaches to provide APS estimates and in-between study variations for humans and all livestock species considered. Sensitivity analyses and bias assessments were conducted using influence plot analysis and, Egger's and Begg's statistics along with funnel plots, respectively. Synthetic review approaches were used to summarize data on isolates and public health awareness. Pooled seroprevalence estimate of brucellosis at national level was 2.6% (95% CI, 2.2-3.0) in cattle, 4% (95% CI, 3.1-5.1) in goats, 3% (95% CI, 2.3-3.9) in sheep and 3% (95% CI, 2.4-3.7) in camels. At a herd level, 16.3% (95% CI, 12.9, 20.5) of cattle, 12.1% (7.1, 19.9) of goat, 13.3% (7.6, 22.1) of sheep and 19.7% (13.8, 27.4) of camel herds in the country had at least one seropositive animal. Cattle in the pastoral/agropastoral production systems had significantly higher (p < 0.05) APS compared to mixed crop-livestock and urban/peri-urban dairy production systems. Pooled seroprevalence of brucellosis in small ruminants (8.3%, 95% CI, 6.3, 10.8) and camels (4.4%, 95% CI, 3.5, 5.6) in Afar were significantly higher (p<0.05) than in other regions. Reports conducted using ELISA and serial Rose Bengal plate test (RBPT)-ELISA had higher (p<0.05) APS estimates than serial RBPT and complement fixation test. Brucella melitensis and B. abortus were reported from goats and cattle, respectively, from three available reports. The APS of brucellosis in humans was 5% (95% CI: 3.3, 7.3). Public awareness of brucellosis was low (18.4%), while, practices that expose humans to Brucella infection were high. Scenario-based control interventions on regions and production systems using one health approach are suggested. This article is protected by copyright. All rights reserved.

Seroprevalence and Risk Factors Associated with Brucella Infection in Camels in the Puntland State of Somalia

Brucellosis is an important zoonotic disease caused by members of the genus Brucella. Camel brucellosis has been reported in almost all camel-rearing countries in Africa and Asia. A cross-sectional study was conducted between February 2020 and February 2021 in Galkayo, Garowe, and Bosaso districts in the Puntland State of Somalia to investigate the seroprevalence and risk factors of brucellosis in camels. A competitive enzyme-linked immunosorbent assay (c-ELISA) was used to detect anti-Brucella antibodies, while a structured questionnaire was used to collect epidemiological data. A total of 441 camel sera were screened against Brucella antibodies. Thirty-one (7%; 95% CI: 4.8–9.8%) samples were positive, and thirteen (54.2%; 95% CI: 32.8–74.4%) out of the twenty-four farms sampled had at least one seropositive animal. Galkayo district had the highest number of Brucella-seropositive camels (10.3%), followed by Bosaso district (8.6%), while Garowe district had the lowest number of seropositive camels (1.4%). The binary logistic regression model revealed that camels in Galkayo district (p = 0.015; OR: 9.428; 95% CI: 1.539–57.755), camels from large herd sizes of >50 animals (p = 0.019; OR: 5.822; 95% CI: 1.336–25.371), and those in contact with small ruminants (p = 0.011; OR: 10.941; 95% CI: 1.728–69.285) were significantly associated with seropositive cases of camel brucellosis in the Puntland State of Somalia. The present study shows that Brucella infections in camels are prevalent in the three districts covered by the study. This poses a public health risk, because milk from these camels is used for human consumption. Studies focusing on the isolation of Brucella strains in camels and investigating brucellosis in ruminants and humans are recommended in the study area. Validation of serological tests—including c-ELISA—for Brucella antibody detection in camels is also needed.

Phenology and phylogeny of Hyalomma spp. ticks infesting one-humped camels (Camelus dromedarius) in the Tunisian Saharan bioclimatic zone

In this study, we report the results of a survey of Hyalomma ticks infesting one-humped camels in southern Tunisia. Examinations were conducted every second or third month on 406 camels in Tataouine district from April 2018 to October 2019. A total of 1902 ticks belonging to the genus Hyalomma were collected. The ticks were identified as adult H. impeltatum (41.1%; n = 782), H. dromedarii (32.9%; n = 626), H. excavatum (25.9%; n = 493), and H. marginatum for a single specimen. Although the camels were infested by ticks throughout the year, the highest overall infestation prevalence was observed in April 2018 (p < 0.01). The overall infestation intensity varied between 2.7 and 7.4 ticks/animal. There were no statistically significant differences in tick infestation prevalence based on age categories of the camels, and the overall infestation prevalence was between 82.7% and 97.4%. Female camels were significantly more infested with ticks (88.3%) than males (65.5%) (p < 0.01). The infestation prevalence of camels varied significantly according to the region where sampling took place (p < 0.01), but no correlations were found with abiotic factors. The preferred attachment sites for adult Hyalomma ticks were the sternum (38.3%; n = 729/1902), around the anus (36.2%; n = 689/1902), udder (18.4%; n = 350/1902), and inner thigh (6.9%; n = 132/1902). Morphological classification of ticks was corroborated by sequencing the cytochrome c oxidase I (Cox1) and 16S rDNA genes, and these sequences were also used to infer phylogenetic relationships. A single H. dromedarii seemed to be a natural hybrid with H. rufipes. More attention should be devoted by the veterinary services to the infestation of camels by ticks.

Serological evidence of single and mixed infections of Rift Valley fever virus, Brucella spp. and Coxiella burnetii in dromedary camels in Kenya

Camels are increasingly becoming the livestock of choice for pastoralists reeling from effects of climate change in semi-arid and arid parts of Kenya. As the population of camels rises, better understanding of their role in the epidemiology of zoonotic diseases in Kenya is a public health priority. Rift Valley fever (RVF), brucellosis and Q fever are three of the top priority diseases in the country but the involvement of camels in the transmission dynamics of these diseases is poorly understood. We analyzed 120 camel serum samples from northern Kenya to establish seropositivity rates of the three pathogens and to characterize the infecting Brucella species using molecular assays. We found seropositivity of 24.2% (95% confidence interval [CI]: 16.5–31.8%) for Brucella, 20.8% (95% CI: 13.6–28.1%) and 14.2% (95% CI: 7.9–20.4%) for Coxiella burnetii and Rift valley fever virus respectively. We found 27.5% (95% CI: 19.5–35.5%) of the animals were seropositive for at least one pathogen and 13.3% (95% CI: 7.2–19.4%) were seropositive for at least two pathogens. B. melitensis was the only Brucella spp. detected. The high sero-positivity rates are indicative of the endemicity of these pathogens among camel populations and the possible role the species has in the epidemiology of zoonotic diseases. Considering the strong association between human infection and contact with livestock for most zoonotic infections in Kenya, there is immediate need to conduct further research to determine the role of camels in transmission of these zoonoses to other livestock species and humans. This information will be useful for designing more effective surveillance systems and intervention measures.

Dromedary camels are well adapted to the arid and semi-arid environment that makes up about 80% of Kenya’s landmass. As such, camels play an important role in the socio-economic wellbeing and food security of pastoralists in the country. However, the species remains relatively neglected in scientific research, one of the main reasons being camels are mostly found in remote, low-income, arid regions of Africa and Asia. We carried out a study to determine the levels of exposure of camels in northern Kenya to Brucella spp., Coxiella burnetii and Rift Valley fever virus, three priority zoonotic pathogens in the country. We found high levels of exposure to the three pathogens, indicating the important role camels might play in the epidemiology of the zoonotic diseases in humans and other livestock. Based on the study findings, we argue for the immediate need for investments in disease surveillance and control strategies for priority zoonotic disease in camels in Kenya.

Coxiella burnetii in Dromedary Camels (Camelus dromedarius): A Possible Threat for Humans and Livestock in North Africa and the Near and Middle East?

The "One Health" concept recognizes that human health is connected to animal health and to the ecosystems. Coxiella burnetii-induced human Q fever is one of the most widespread neglected zoonosis. The main animal reservoirs responsible for C. burnetii transmission to humans are domesticated ruminants, primarily goats, sheep, and cattle. Although studies are still too sparse to draw definitive conclusions, the most recent C. burnetii serosurvey studies conducted in herds and farms in Africa, North Africa, Arabian Peninsula, and Asia highlighted that seroprevalence was strikingly higher in dromedary camels (Camelus dromedarius) than in other ruminants. The C. burnetii seroprevalence in camel herds can reach more than 60% in Egypt, Saudi Arabia, and Sudan, and 70 to 80% in Algeria and Chad, respectively. The highest seroprevalence was in female camels with a previous history of abortion. Moreover, C. burnetii infection was reported in ticks of the Hyalomma dromedarii and Hyalomma impeltatum species collected on camels. Even if dromedary camels represent <3% of the domesticated ruminants in the countries of the Mediterranean basin Southern coast, these animals play a major socioeconomic role for millions of people who live in the arid zones of Africa, Middle East, and Asia. In Chad and Somalia, camels account for about 7 and 21% of domesticated ruminants, respectively. To meet the growing consumers demand of camel meat and milk (>5 million tons/year of both raw and pasteurized milk according to the Food and Agriculture Organization) sustained by a rapid increase of population (growth rate: 2.26-3.76 per year in North Africa), dromedary camel breeding tends to increase from the Maghreb to the Arabic countries. Because of possible long-term persistence of C. burnetii in camel hump adipocytes, this pathogen could represent a threat for herds and breeding farms and ultimately for public health. Because this review highlights a hyperendemia of C. burnetii in dromedary camels, a proper screening of herds and breeding farms for C. burnetii is urgently needed in countries where camel breeding is on the rise. Moreover, the risk of C. burnetii transmission from camel to human should be further evaluated.

Isolation of Brucella melitensis from seronegative camel: potential implications in brucellosis control

Brucellosis is a significant zoonotic infection in Iran impacting both humans and animal health status. A number of reasons such as few clinical signs complicate the diagnosis of this infection in Camelidae. Despite the ubiquitous use of serological tests for the first screening of brucellosis in camel, this approach showed several restrictions because of the intracellular properties of this organism as well as decline antibody titers in chronic stage. This study aimed at identifying the presence of Brucella spp. in blood and lymph node samples collected from slaughtered male camels of Sistan-Baluchistan province by serology, culture and polymerase chain reaction (PCR) assay. For this purpose, 2854 blood camel samples were sampled and analyzed for Brucella detection by serological screening tests. The molecular detection of IS711 gene and Bruce-ladder assay as well as culture were performed using the lymph nodes of all seropositive camel (n = 10) and 30 seronegative samples. Results showed that 0.35% (10/2854), 0.24% (7/2854) and 0.21% (6/2854) of blood samples were positive by RBPT, SAT and 2ME, respectively. However, 0% (0/10) and 70% (7/10) of lymph node samples collected from seropositive camels were positive for Brucella infection by culture and PCR, respectively. Furthermore, 6.6% (2/30) of seronegative lymph node specimens showed the presences of Brucella by PCR and culture assay. The results of the present study indicated the low seroprevalence of Brucella infection in male camels of the Sistan-Baluchistan province and highlighted the complementary role of PCR techniques for a better screening of Brucella infection among seronegative camels. Moreover, the potential shedding of Brucella within undiagnosed camel milk and secretions is a serious problem which may result in further spread and maintenance of Brucella infection among both human and livestock. Thus, for brucellosis detection and control, our results suggested that a first PCR screening supported by a bacteriological isolation on positive samples should be performed along with the serological test in endemic countries to identify the source and prevent the uncontrolled spread of the disease among camels.

Seroprevalence and Molecular Identification of Brucella spp. in Camels in Egypt

Brucellosis is one of the most important worldwide zoonoses of many countries including Egypt. Camel brucellosis has not gained much attention in Egypt yet. This study is focused on the three governorates with the highest camel populations and the largest camel markets in the country to determine the disease seroprevalence and identify the Brucella species in local camel holdings. In total, 381 serum samples were collected from male and female camels from Giza, Aswan, and Al-Bahr Al-Ahmar (the Red Sea) governorates. Samples were serologically examined using the Rose-Bengal plate test (RBPT), indirect ELISA (i-ELISA), competitive ELISA (c-ELISA) and complement fixation test (CFT). Brucella antibodies were detected in 59 (15.5%), 87 (22.8%), 77 (20.2%) and 118 (31.0%) of sera by RBPT, i-ELISA, c-ELISA and CFT, respectively. Using real-time PCR, Brucella DNA was amplified in 32 (8.4%) seropositive samples including Brucella abortus (25/32), Brucella suis (5/32) and Brucella melitensis (2/32), defining a complex epidemiological status. To the best of our knowledge, this is the first study reporting Brucella suis DNA in camel serum. The risk-associated factors including age, sex, breed and geographical distribution were statistically analyzed, showing non-significant association with seroprevalence. The results of this study will raise awareness for camel brucellosis and help develop effective control strategies.

Brucellosis in the Middle East: Current situation and a pathway forward

Brucellosis is a bacterial endemic zoonotic disease of global significance with detrimental impacts on public health and food animal production. It is caused by Brucella spp., an expanding group of pathogens able to infect various host species. Bovines and small ruminants, which excrete the bacteria in milk and in reproductive discharges, are major sources of infection for humans and other animals. Contact with contaminated animals and consumption of unpasteurized dairy products are the main routes for human infection. In spite of the considerable progress of knowledge gained and success achieved in brucellosis control in the developed world, this disease continues to be an important burden in the Middle East (ME). Common risk factors implicated in the difficulty and complexity of brucellosis control within the region include (1) social and political instabilities; (2) insufficient resources and infrastructure for appropriate diagnosis, reporting, and implementation of control measures; (3) variation of livestock husbandry systems and their commingling with other livestock and wildlife; and (4) traditional cultural practices, including consumption of unpasteurized dairy products. Development of core interdisciplinary competencies is required for a true One Health–based endeavor against the disease. National awareness and educational programs addressing all population sectors from consumers to decision-makers seem to be the next logical, sustainable, and economically viable approach toward improving disease status in this region. In the present review, we describe the current situation of brucellosis in the ME, focusing on the major limitations and shortcomings regarding disease control. We propose a regional approach toward public awareness of brucellosis as the first step in mitigating the disease and discuss the potential benefits, and components of such a strategy, which can further be used as a model for other endemic zoonotic diseases.

Sentinel surveillance of selected veterinary and public health pathogens in camel population originating from Southern Punjab province, Pakistan

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Camels are susceptible to a wide range of infectious diseases with varying rate of morbidity and mortality.

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Blutongue, peste des petits ruminants and brucellosis are prevalent among camels in southern part of the Punjab provinvce, Pakistan.

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Genome corresponding to Brucella abortus and multiple serotypes of bluetongue were detected among camels.

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Camels should be included for disease control interventions reltaed to brucellosis, blutongue and PPR from their endemic setting worldwide.

An extended range of host susceptibility including camel has been evidenced for some of the important veterinary and public health pathogens, such as brucellosis, peste des petits ruminants (PPR) and bluetongue (BT). However, in disease endemic settings across many parts of the globe, most of the disease control interventions accounts for small and large ruminants, whereas unusual hosts and/or natural reservoirs, such as camels, remain neglected for disease control measures including routine vaccination. Such a policy drawback not only plays an important role in disease epizootiology particularly in settings where disease is endemic, but also serves an obstacle in disease control and subsequent eradication in future. With this background, using pre-validated ELISA and molecular assays [multiplex PCR, reverse transcriptase (RT)-PCR and real-time (rt)-PCR], we conducted a large-scale pathogen- and antibody-based surveillance for brucellosis, peste des petits ruminants and bluetongue in camel population (n = 992) originating from a wide geographical region in southern part of the Punjab province, Pakistan. Varying in each of the selected districts, the seroprevalence was found to be maximum for bluetongue [n = 697 (70.26%, 95% CI: 67.29–73.07)], followed by PPR [n = 193 (19.46%, 95% CI: 17.07–22.09)] and brucellosis [n = 66 (6.65%, 95% CI: 5.22–8.43)]. Odds of seroprevalence were more significantly associated with pregnancy status (non-pregnant, OR = 2.23, 95% CI: 1.86–5.63, p<0.01), farming system (mixed-animal, OR = 2.59, 95% CI: 1.56–4.29, p<0.01), breed (Desi, OR = 1.97, 95% CI: 1.28–4.03, p<0.01) and farmer education (illiterate, OR = 3.17, 95% CI: 1.45–6.93, p<0.01) for BTV, body condition (normal, OR = 3.54, 95% CI: 1.92–6.54, p<0.01) and breed (Desi, OR = 2.19, 95% CI: 1.09–4.40, p<0.01) for brucellosis, and feeding system for PPR (grazing, OR = 2.75, 95% CI: 1.79–4.22, p<0.01). Among the total herds included (n = 74), genome corresponding to BT virus (BTV) and brucellosis was detected in 14 (18.92%, 95 CI: 11.09–30.04) and 19 herds (25.68%, 95% CI: 16.54–37.38), respectively. None of the herds was detected with genome of PPR virus (PPRV). Among the positive herds, serotype 1, 8 and 11 were detected for BTV while all the herds were exclusively positive to B. abortus. Taken together, the study highlights the role of potential disease reservoirs in the persistence and transmission of selected diseases in their susceptible hosts and, therefore, urges necessary interventions (e.g., inclusion of camels for vaccine etc.) for the control of diseases from their endemic setting worldwide.

Comparison of knowledge, attitude, and practices of animal and human brucellosis between nomadic pastoralists and non-pastoralists in Kenya

BACKGROUND

The seroprevalence of brucellosis among nomadic pastoralists and their livestock in arid lands is reported to be over10-fold higher than non-pastoralists farmers and their livestock in Kenya. Here, we compared the seroprevalence of nomadic pastoralists and mixed farming with their knowledge of the disease and high-risk practices associated with brucellosis infection.

METHODS

Across-sectional study was conducted in two counties - Kiambu County where farmers primarily practice smallholder livestock production and crop farming, and Marsabit County where farmers practice nomadic pastoral livestock production. Stratified random sampling was applied, in which sublocations were initially selected based on predominant livestock production system, before selecting households using randomly generated geographical coordinates. In each household, up to three persons aged 5 years and above were randomly selected, consented, and tested for Brucella spp IgG antibodies. A structured questionnaire was administered to the household head and selected individuals on disease knowledge and risky practices among the pastoralists and mixed farmers compared. Multivariable mixed effects logistic regression model was used to assess independent practices associated with human Brucella spp. IgG seropositivity.

RESULTS

While the majority (74%) of pastoralist households had little to no formal education when compared to mixed (8%), over 70% of all households (pastoralists and mixed farmers) had heard of brucellosis and mentioned its clinical presentation in humans. However, fewer than 30% of all participants (pastoralists and mixed farmers) knew how brucellosis is transmitted between animals and humans or how its transmission can be prevented. Despite their comparable knowledge, significantly more seropositive pastoralists compared to mixed farmers engaged in risky practices including consuming unboiled milk (79.5% vs 1.7%, p < 0.001) and raw blood (28.3% vs 0.4%, p < 0.001), assisting in animal birth (43.0% vs 9.3%, p < 0.001), and handling raw hides (30.6% vs 5.5%, p < 0.001).

, CONCLUSION

Nomadic pastoralists are more likely to engage in risky practices that promote Brucella Infection, probably because of their occupation and culture, despite having significant knowledge of the disease.

Brucella abortus contamination of camel milk in two Iranian regions

Brucella spp. commonly infect humans in various regions worldwide. Human brucellosis mainly spreads through the consumption of contaminated raw dairy products and meat from domestic livestock (water buffalo, goats, sheep, cattle, pigs and camels). In this regard, the origin and routes of transmission of this bacterium should be carefully determined in order to control the source of infection. This study aimed to evaluate the rate of Brucella spp. contamination of camel milk samples sent for analysis to the national brucellosis laboratory during 2018 in Iran. For this purpose, 96 milk samples from 96 dairy camel herds were randomly collected from two provinces and investigated for the presence of Brucella spp contaminations by both bacterial culture method and polymerase chain reaction (PCR). No clinical manifestation of brucellosis was reported in camels from which milk samples were collected. Using the culture method, three milk samples (3%) originating from two camels of Isfahan province (4%) and one camel from the Semnan province (2%), were contaminated with Brucella abortus. According to PCR analyses, B. abortus gene was detected in 14 (14.5%) milk samples, including 9 and 5 samples from Isfahan (18%) and Semnan (11%) province, respectively. PCR method revealed significant differences (p = 0.02) in the level of contamination with B. abortus between milk samples collected from two regions. These results represent the first report regarding the isolation of B. abortus from raw camel milk in Iran and highlight the importance to screen apparent healthy camels. Therefore, the consumption of raw camel milk may contribute to the spread of human brucellosis in endemic regions.

First Genome Sequence of Brucella abortus Biovar 3 Strain BAU21/S4023, Isolated from a Dairy Cow in Bangladesh

We report the genome sequence of Brucella abortus biovar 3 strain BAU21/S4023, isolated from a dairy cow that suffered an abortion in Savar, Dhaka, Bangladesh. The genome sequence length is 3,244,234 bp with a 57.2% GC content, 3,147 coding DNA sequences (CDSs), 51 tRNAs, 1 transfer messenger RNA (tmRNA), and 3 rRNA genes.

We report the genome sequence of Brucella abortus biovar 3 strain BAU21/S4023, isolated from a dairy cow that suffered an abortion in Savar, Dhaka, Bangladesh. The genome sequence length is 3,244,234 bp with a 57.2% GC content, 3,147 coding DNA sequences (CDSs), 51 tRNAs, 1 transfer messenger RNA (tmRNA), and 3 rRNA genes.

A Review of Zoonotic Pathogens of Dromedary Camels

Dromedary, or one-humped, camels Camelus dromedarius are an almost exclusively domesticated species that are common in arid areas as both beasts of burden and production animals for meat and milk. Currently, there are approximately 30 million dromedary camels, with highest numbers in Africa and the Middle East. The hardiness of camels in arid regions has made humans more dependent on them, especially as a stable protein source. Camels also carry and may transmit disease-causing agents to humans and other animals. The ability for camels to act as a point source or vector for disease is a concern due to increasing human demands for meat, lack of biosafety and biosecurity protocols in many regions, and a growth in the interface with wildlife as camel herds become sympatric with non-domestic species. We conducted a literature review of camel-borne zoonotic diseases and found that the majority of publications (65%) focused on Middle East respiratory syndrome (MERS), brucellosis, Echinococcus granulosus, and Rift Valley fever. The high fatality from MERS outbreaks during 2012-2016 elicited an immediate response from the research community as demonstrated by a surge of MERS-related publications. However, we contend that other camel-borne diseases such as Yersinia pestis, Coxiella burnetii, and Crimean-Congo hemorrhagic fever are just as important to include in surveillance efforts. Camel populations, particularly in sub-Saharan Africa, are increasing exponentially in response to prolonged droughts, and thus, the risk of zoonoses increases as well. In this review, we provide an overview of the major zoonotic diseases present in dromedary camels, their risk to humans, and recommendations to minimize spillover events.

A cross-sectional seroepidemiological study of camel (Camelus dromedarius) brucellosis and associated risk factors in the Sultanate of Oman

Brucellosis is a globally distributed and economically devastating zoonotic disease of multiple species, including camels. Human and livestock brucellosis is prevalent in Oman, especially in southern Dhofar governorates of Oman, where camels share habitat and have close contact with other susceptible species. We conducted a randomized cross-sectional sero-epidemiological study to investigate the seroprevalence of brucellosis in camels of Oman. The sera from 2,250 camels from 552 geographically marked farms were screened through Rose Bengal plate agglutination test and later confirmed by the competitive ELISA (COMPLIZA, VLA, UK). In total, nine [0.4%, confidence interval (CI) 0.4, 0.8] camels from eight (1.5%, CI 0.6, 2.8) herds were tested positive for brucellosis. The highest prevalence was recorded in Dhofar (3.7%, CI 1.4, 7.9) and the lowest in Sharqiyah (1.3%, CI 0.0, 7.2) governorate (p = 0.052). All seropositive camels were of local breed and females. Seroprevalence was higher (0.5%, CI 0.2, 1.0) in adults (>4 yr of age) as compared with young (≤4 yr of age) camels (0.2%, CI 0.0, 0.8). The results of binary logistic regression indicated that camel herds located in south (Dhofar) [odds ratio (OR) 6.39, CI 1.01, 40.67], practice of open replacement system (OR 14.49, CI 1.83, 114.51) and with history of abortions (OR 8.01, CI 1.34, 47.77) were more likely to test positive for brucellosis. We conclude that brucellosis is endemic at a low level in camels of Oman and a control strategy based upon test-and-slaughter/inclusion of camels in the current vaccination program after carefully planned vaccine evaluation studies could be considered to control it.

Morphometric and genetic variation in 8 breeds of Ethiopian camels (Camelus dromedarius)

Dromedary camels (Camelus dromedarius) are a domesticated and closely guarded economic staple of indigenous people located throughout Ethiopian territorial states. Seventeen morphometric variables were examined to determine intraspecific variation among 8 pastoralist-designated breeds of camels. Additionally, DNA sequences from mitochondrial cytochrome-b gene and genotyping of 6 nuclear microsatellite loci were examined to assess genetic diversity and phylogenetic relationship of Ethiopian camels. Examination of 525 individuals revealed significant morphometric differentiation in Afar as compared with the remaining 7 breeds. Analysis of cytochrome-b sequences failed to recover monophyletic groups associated with pastoralist-recognized breeds. Analysis of 6 microsatellite loci from 104 individuals depicted no resolution of distinct genetic lineages in accordance to geographical or designated breeds. Overall, separation of 2 ecotypes based on the morphometric data was supported; however, genetic analysis of cytochrome-b and microsatellite data failed to support any unique genetic lineage or statistically significant population structure.

Risk factors of brucellosis seropositivity in Bactrian camels of Mongolia

BACKGROUND

More information on brucellosis epidemiology in Bactrian camels is needed due to their growing economic and livelihood importance for herders and renewed efforts in Mongolia to eliminate brucellosis through mass vaccination of ruminants excluding camels. Brucellosis prevalence in camels increased over the past two decades. Random multi-stage cluster surveys were done in the Eastern provinces of Dornod and Sukhbaatar in 2013 and 2014 and in the Southern & Western provinces of Dornogobi, Umnogobi and Khovd in 2014 and 2015. A total of 1822 camels, 1155 cattle, and 3023 small ruminant sera were collected and tested with the Rose Bengal Test. In addition, 195 vaginal swabs and 250 milk samples for bacteriological culture were taken from livestock with history of abortion.

RESULTS

The overall apparent seroprevalence in camels was 2.3% (95% confidence interval 1.6-3.3). The main risk factor for camel seropositivity was being in an Eastern province when compared to Southern & Western provinces (odds ratio 13.2, 95% CI 5.3-32.4). Camel seroprevalences were stable over the two consecutive survey years, despite introduction of ruminant vaccination: 5.7% (95% CI 3.1-10.2%) and 5.8% (3.3-10.1%) in Eastern provinces and 0.4% (0.2-1.2%) and 0.5% (0.1-2.0%) in Southern & Western provinces. We isolated Brucella abortus from camels and cattle. Camel seropositivity was associated to keeping cattle together with camels. Monitoring of vaccination campaigns showed that coverage in cattle was insufficient because animals could not be adequately restrained.

CONCLUSIONS

The present study reveals that brucellosis is present with important seroprevalence in Mongolian camels and was endemic in Eastern provinces. Camel herd seropositivity was most closely associated to infection in cattle. Longer term monitoring is needed to assess whether camel seroprevalance decreases with ongoing vaccination in Mongolia. This should be coupled with further confirmation on Brucella spp. isolates. To date, only Brucella abortus was isolated, but camels are also susceptible to Brucella melitensis. Clear verbal and written information on disease prevention in livestock and household members is important, particularly for remote camel herders who had only moderate knowledge on brucellosis epidemiology and preventive measures.

An Overview of Brucellosis in Cattle and Humans, and its Serological and Molecular Diagnosis in Control Strategies

Brucellosis is one of the most common contagious and communicable zoonotic diseases with high rates of morbidity and lifetime sterility. There has been a momentous increase over the recent years in intra/interspecific infection rates, due to poor management and limited resources, especially in developing countries. Abortion in the last trimester is a predominant sign, followed by reduced milk yield and high temperature in cattle, while in humans it is characterized by undulant fever, general malaise, and arthritis. While the clinical picture of brucellosis in humans and cattle is not clear and often misleading with the classical serological diagnosis, efforts have been made to overcome the limitations of current serological assays through the development of PCR-based diagnosis. Due to its complex nature, brucellosis remains a serious threat to public health and livestock in developing countries. In this review, we summarized the recent literature, significant advancements, and challenges in the treatment and vaccination against brucellosis, with a special focus on developing countries.

African Lineage Brucella melitensis Isolates from Omani Livestock

Brucellosis is a common livestock disease in the Middle East and North Africa, but remains poorly described in the region both genetically and epidemiologically. Traditionally found in goats and sheep, Brucella melitensis is increasingly recognized as infecting camels. Most studies of brucellosis in camels to date have focused on serological surveys, providing only limited understanding of the molecular epidemiology of circulating strains. We genotyped B. melitensis isolates from Omani camels using whole genome SNP assays and VNTRs to provide context for regional brucellosis cases. We identified a lineage of B. melitensis circulating in camels as well as in goats, sheep, and cattle in Oman. This lineage is genetically distinct from most genotypes from the Arabian Peninsula and from isolates from much of the rest of the Middle East. We then developed diagnostic assays that rapidly identify strains from this lineage. In analyses of genotypes from throughout the region, Omani isolates were genetically most closely related to strains from brucellosis cases in humans and livestock in North Africa. Our findings suggest an African origin for B. melitensis in Oman that has likely occurred through the trade of infected livestock. Moreover, African lineages of B. melitensis appear to be undersampled and consequently are underrepresented in genetic databases for Brucella. As we begin to more fully understand global genomic diversity of B. melitensis, finding and characterizing these unique but widespread lineages is essential. We predict that increased sampling of humans and livestock in Africa will reveal little known diversity in this important zoonotic pathogen.

Emerging Infectious Diseases in Camelids

Growing interest in camelids presents a unique challenge to scientists and veterinarians engaged in diagnosing infectious diseases of this species. It is estimated that 65 % of fatalities in Old World camels (OWC, i.e., Camelus dromedarius and C. bactrianus) and 50 % in New World camelids/South American camelids (NWC/SAC, i.e., the domestic alpaca (Vicugna pacos) and llama (Lama glama)) are caused by infectious diseases. Factors that contribute to disease emergence in camelids involve climate change and increased demand for camel products resulting in the intensification of production and expanding camel contacts with other animal species and humans. In this chapter, the most important emerging diseases of camelids are described and discussed. The most notable emerging viral infections in OWC include camelpox, Rift Valley fever (RVF), peste des petits ruminants (PPR), and Middle East respiratory syndrome coronavirus (MERS-CoV) infection. Brucellosis, Johne’s disease (JD), and dermatophilosis are the emerging bacterial diseases in OWC. Emerging diseases of NWC include infections with bovine viral diarrhea virus (BVDV), bluetongue (BT), and coronavirus. Parasitic emerging infections in NWCs include the small liver fluke (Dicrocoelium dendriticum) and meningeal worm (Parelaphostrongylus tenuis).

Brucellosis in Sub-Saharan Africa: Current challenges for management, diagnosis and control

Brucellosis is a highly contagious zoonosis caused by bacteria of the genus Brucella and affecting domestic and wild mammals. In this paper, the bacteriological and serological evidence of brucellosis in Sub-Saharan Africa (SSA) and its epidemiological characteristics are discussed. The tools available for the diagnosis and treatment of human brucellosis and for the diagnosis and control of animal brucellosis and their applicability in the context of SSA are presented and gaps identified. These gaps concern mostly the need for simpler and more affordable antimicrobial treatments against human brucellosis, the development of a B. melitensis vaccine that could circumvent the drawbacks of the currently available Rev 1 vaccine, and the investigation of serological diagnostic tests for camel brucellosis and wildlife. Strategies for the implementation of animal vaccination are also discussed.

Serological, molecular detection and potential risk factors associated with camel brucellosis in Pakistan

Brucellosis is one of the most important zoonoses in developing countries and was considered the most widespread zoonosis in the world. Brucellosis was reported in camels and has been reported from all camel-keeping countries.The present study was performed in three districts (Jhang, Chiniot, and Bhakkar) of Punjab province of Pakistan. A total of 200 camel (Camelus bactrianus) sera were collected using random and multistage cluster sampling from different areas. Fifty samples were collected from one organized governmental farm. One hundred fifty samples were collected randomly from nomadic/pastoral production systems. All sera were tested with Rose Bengal plate agglutination test (RBPT) and confirmed by ELISA. Genomic DNA was extracted from all serum samples and tested by real-time PCR. Various potential risk factors (season, rearing with other animals, and abortion or orchitis history) recorded through questionnaires were statistically analyzed by Chi-square test.In total, 5 % of investigated sera were positive by RBPT. Only 2 % of the camel sera were CELISA positive. Brucella abortus DNA was detected in 1.5 % of the investigated animals. Season, rearing of camels with other ruminants, abortion, and orchitis history were found to be statistically significant (p < 0.05) disease for determinants.Camel brucellosis is a zoonotic disease in the Pakistani Punjab with various risk factors maintaining and perpetuating its spread. Therefore, there is a need for implementing control measures and raising public health awareness in prevention of brucellosis in Pakistan.

Genotyping of Brucella melitensis strains from dromedary camels (Camelus dromedarius) from the United Arab Emirates with multiple-locus variable-number tandem repeat analysis

Camel brucellosis is a widespread zoonotic disease in camel-rearing countries caused by Brucella melitensis and Brucella abortus. The aim of this study was the first genetic analysis of B. melitensis strains isolated from dromedary camels (Camelus dromedarius) using multiple-locus variable-number tandem repeat analysis (MLVA). MLVA 16 and its MLVA 8 and MLVA11 subsets were used to determine the genotypes of 15 B. melitensis isolates from dromedary camels (11 strains) and other host species (4 strains) from the United Arab Emirates and the results were then compared to B. melitensis MLVA genotypes from other parts of the world. Five, including two novel genotypes were identified with MLVA 8. MLVA 16 further discriminated these five genotypes to ten variants. The eleven camel isolates clustered into four main genetic groups within the East-Mediterranean and African clades and this clustering correlated with the geographic origin of the hosts (United Arab Emirates, Kingdom of Saudi Arabia and Sudan) and the date of their isolation. The camel strains were also genetically related to strains isolated from wild and domestic ruminants from their close habitat or from other parts of the world. Although limited number of strains were analysed, based on our data imported animals from foreign countries, local small ruminants and wildlife species are hypothesized to be the main sources of camel brucellosis in the United Arab Emirates. MLVA was successfully applied to determine the epidemiological links between the different camel B. melitensis infections in the United Arab Emirates and it can be a beneficial tool in future disease control programs.

A new method for simultaneous gene deletion and down-regulation in Brucella melitensis Rev.1

In this study, our aim was to integrate an antisense expression cassette in bacterial chromosome for providing a long-term expression down-regulation in a bid to develop a new approach for simultaneous deletion and down-regulation of target genes in bacterial system. Therefore, we were used this approach for simultaneous deletion of the perosamine synthetase (per) gene and down-regulation of the virB1 expression in Brucella melitensis Rev.1. The per gene, which is one of the LPS O-chain coding genes, was replaced by homologous recombination with an antisense virB1 expression cassette together with kanamycin resistance cassette (kan(R)). Deletion of the per gene was characterized by PCR analysis and DNA sequencing. The expression of antisense virB1 cassette was confirmed by RT-PCR. Down-regulation of the virB1 mRNA expression was quantified by real-time RT-PCR using virB1 specific primers relative to the groEL reference gene. The survival rate of mutant strain was evaluated by CFU count in the BALB/c mice. The virB1 mRNA expression was down-regulated on average 10-fold in mutant strain as compared to parental strain. The loss of per gene function and decrease of the virB1 mRNA expression resulted in reduced entry and survival of the mutant Rev.1 strain in BALB/c mice splenocytes. We propose that this method can be used for simultaneous regulation of multiple genes expression.

Identification and isolation of stimulator of interferon genes (STING): an innate immune sensory and adaptor gene from camelids

The mechanism by which type I interferon-mediated antiviral response is mounted by hosts against invading pathogen is an intriguing one. Of late, an endoplasmic reticulum transmembrane protein encoded by a gene called stimulator of interferon genes (STING) is implicated in the innate signalling pathways and has been identified and cloned in few mammalian species including human, mouse and pig. In this article, we report the identification of STING from three different species of a highly conserved family of mammals - the camelids. cDNAs encoding the STING of Old World camels - dromedary camel (Camelus dromedarius) and bactrian camel (Camelus bactrianus) and a New World camel - llama (Llama glama) were amplified using conserved primers and RACE. The complete STING cDNA of dromedary camel is 2171 bp long with a 706-bp 5' untranslated regions (UTR), an 1137-bp open reading frame (ORF) and a 328-bp 3' UTR. Sequence and phylogenetic analysis of the ORF of STING from these three camelids indicate high level of similarity among camelids and conservation of critical amino acid residues across different species. Quantitative real-time PCR analysis revealed high levels of STING mRNA expression in blood, spleen, lymph node and lung. The identification of camelid STING will help in better understanding of the role of this molecule in the innate immunity of the camelids and other mammals.