Exploring genetic diversity and variation of Ovar-DRB1 gene in Sudan Desert Sheep using targeted next-generation sequencing.

INTRODUCTION: The Ovar-DRB1 gene, a crucial element of the Major Histocompatibility Complex (MHC) Class II region, initiates adaptive immunity by presenting antigens to T-cells. Genetic diversity in sheep, particularly in MHC Class II genes like Ovar-DRB1, directly influences the specturm of presented antigens impacting immune responses and disease susceptability. Understanding the allelic diversity of Ovar-DRB1 gene in Sudan Desert Sheep (SDS) is essential for uncovering the genetic basis of immune responses and disease resistance, given the the breeds significance in Sudan's unique environment. METHODS: Utilizing Targeted Next-Generation Sequencing (NGS) we explore allelic diversity in Ovar-DRB1 gene within SDS. Successfully ampliying and and sequencing the second exon of this gene in 288 SDS samples representing six breeds provided a comprehensive allelic profile, enabling a detalied examination of the gene's genetic makeup. RESULTS: We identifed forty-six alleles, including four previously unreported, enrichness the genetic diversity of SDS breeds. These alleles exhibiting non-uniform distribution, varying frequencies across breeds, indicating a breed-specific genetic landscape. Certain alleles, known and novel, show higher frequencies in specific populations, suggesting potential associations with adaptive immune responses. Identifying these alleles sets the stage for investigating their functional roles and implications for disease resistance. Genetic differentiation among SDS breeds, as indicated by FST values and clustering analyses, highlights a unique genetic makeup shaped by geographic and historical factors. These differentiation patterns among SDS breeds have broader implications for breed conservation and targeted breeding to enhance disease resistance in specific populations. CONCLUSION: This study unveils Ovar-DRB1 gene allelic diversity in SDS breeds through targeted NGS and genetic analyses, revealing new alleles that underscore the breeds' unique genetic profile. Insights into the genetic factors governing immune responses and disease resistance emerge, promising for optimization of breeding strategies for enhanced livestock health in Sudan's unique environment.

Intra- and interspecies variation and population dynamics of Fasciola gigantica among ruminants in Sudan.

Fasciola gigantica is a widespread parasite that causes neglected disease in livestock worldwide. Its high transmissibility and dispersion are attributed to its ability to infect intermediate snail hosts and adapt to various mammalian definitive hosts. This study investigated the variation and population dynamics of F. gigantica in cattle, sheep, and goats from three states in Sudan. Mitochondrial cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit 1 (ND1) genes were sequenced successfully to examine intra and interspecific differences. ND1 exhibited higher diversity than COI, with 15 haplotypes and 10 haplotypes, respectively. Both genes had high haplotype diversity but low nucleotide diversity, with 21 and 11 polymorphic sites for ND1 and COI, respectively. Mismatch distribution analysis and neutrality tests revealed that F. gigantica from different host species was in a state of population expansion. Maximum likelihood phylogenetic trees and median networks revealed that F. gigantica in Sudan and other African countries had host-specific and country-specific lineages for both genes. The study also indicated that F. gigantica-infected small ruminants were evolutionarily distant, suggesting deep and historical interspecies adaptation.

Exploring the potential roles of some rodents in the transmission of the Middle East respiratory syndrome coronavirus.

Middle East respiratory syndrome coronavirus (MERS-CoV) is one of the recently identified zoonotic coronaviruses. The one-hump camels are believed to play important roles in the evolution and transmission of the virus. The animal-to-animal, as well as the animal-to-human transmission in the context of MERS-CoV infection, were reported. The camels shed the virus in some of their secretions, especially the nasal tract. However, there are many aspects of the transmission cycle of the virus from animals to humans that are still not fully understood. Rodents played important roles in the transmission of many pathogens, including viruses and bacteria. They have been implicated in the evolution of many human coronaviruses, especially HCoV-OC43 and HCoV-HKU1. However, the role of rodents in the transmission of MERS-CoV still requires more exploration. To achieve this goal, we identified MERS-CoV that naturally infected dromedary camel by molecular surveillance. We captured 15 of the common rodents (rats, mice, and jerboa) sharing the habitat with these animals. We collected both oral and rectal swabs from these animals and then tested them by the commercial MERS-CoV real-time-PCR kits using two targets. Despite the detection of the viral shedding in the nasal swabs of some of the dromedary camels, none of the rodents tested positive for the virus during the tenure of this study. We concluded that these species of rodents did not harbor the virus and are most unlikely to contribute to the transmission of the MERS-CoV. However, further large-scale studies are required to confirm the potential roles of rodents in the context of the MERS-CoV transmission cycle, if any.

Genetic Diversity and Population Structure of Dromedary Camel-Types.

The dromedary camel is a unique livestock for its adaptations to arid-hot environments and its ability to provide goods under extreme conditions. There are no registries or breed standards for camels. Thus, named camel populations (i.e., camel-types) were examined for genetic uniqueness and breed status. Camel populations are generally named based on shared phenotype, country or region of origin, tribal ownership, or the ecology of their habitat. A dataset of 10 Short-Tandem Repeat markers genotyped for 701 individual camels from 27 camel-types was used to quantify genetic diversity within camel-types, compare genetic diversity across camel-types, determine the population genetic structure of camel-types, and identify camel-types that may represent true breeds. Summary statistics (genotyping call rate, heterozygosity, inbreeding coefficient FIS, and allelic frequencies) were calculated and population-specific analyses (pairwise FST, neighbor-joining tree, relatedness, Nei's genetic distance, principal coordinate analysis [PCoA], and STRUCTURE) were performed. The most notable findings were 1) little variation in genetic diversity was found across the camel-types, 2) the highest genetic diversity measure was detected in Targui and the lowest was in Awarik, 3) camel-types from Asia (especially the Arabian Peninsula) exhibited higher genetic diversity than their counterparts in Africa, 4) the highest DeltaK value of population structure separated camel-types based on geography (Asia vs. Africa), 5) the most distinct camel-types were the Omani, Awarik, and the Gabbra, 6) camel-types originating from the same country did not necessarily share high genetic similarity (e.g., camel-types from Oman), and 7) camel-type names were not consistently indicative of breed status.

Dromedary camel CD14high MHCIIhigh monocytes display inflammatory properties and are reduced in newborn camel calves.

BACKGROUND: In human and different animal species, blood monocytes are classified based on their expression pattern of different monocytic markers into phenotypically and functionally different subsets. In the current study, we used flow cytometry and monoclonal antibodies to CD172a, CD14, CD163 and MHCII to identify monocyte subsets in peripheral blood of dromedary camels. RESULTS: Based on CD14, CD163 and MHCII expression, camel CD172a + monocytes were divided into three subsets: The major subpopulation of camel monocytes (mo-I) showed high expression of CD14 and CD163, but low expression of MHCII. A second subset of monocytes (mo-II) expressed highly all three markers, CD14, CD163 and MHCII. A third monocyte subset (mo-III) displayed low expression of CD14 and CD163 with high MHCII expression. While the two MHCIIhigh subsets (mo-II and mo-III) showed higher expression of CD11a in comparison to the MHCIIlow subset (mo-I), CD18 and CD11b were highest expressed on the two CD14high subsets (mo-I and mo-II). Bacterial stimulation of camel leukocytes identified mo-II cells as an antimicrobial monocyte subset with the highest phagocytic and ROS production capacity. The comparison of monocyte counts and phenotype between newborn calves and adult camels revealed significantly reduced numbers of mo-II cells in newborn animals. Monocytes of newborns expressed significantly more CD172a and CD163 molecules but less CD14 and MHCII molecules than monocytes of adult camels. CONCLUSIONS: Camel monocyte subsets, mo-I, mo-II and mo-III are counterparts of bovine classical, intermediate and non-classical monocytes respectively. The distribution of camel monocyte subsets is influenced by age.

Investigation of total immunoglobulin G concentration, heavy chain antibody levels, and neutrophil to lymphocyte ratio in female camels and their newborn calves.

Camels belong to a group of animals, where the structure of placenta does not allow intrauterine transfer of maternal immunoglobulins to the fetus and maternal immunity is exclusively transferred by colostrum to the newborn calf. There are few studies on the passive transfer of maternal immunity in the dromedary camel. This study determined total immunoglobulin G concentration, heavy chain antibody (HCAbs) levels, and neutrophils to lymphocytes ratio (NLR) in female camels and their newborn calves. For this, samples were collected from nine she-camels (blood and colostrum) and their calves (blood). IgG concentration and HCAb level were determined in mother serum and colostrum as well as in calf serum using ELISA. The NLR was calculated after the estimation of relative fractions of neutrophils and lymphocytes in collected blood samples using a blood cell analyzer. Both IgG and HCAbs were higher concentrated in camel colostrum than in mother serum. At parturition and before the first colostrum intake, calf serum did not contain any measurable concentration of IgG and only low levels of HCAbs. After colostrum consumption, a rise in IgG and HCAb levels was observed in calf serum. For total IgG, a minimum was reached on day 30 postnatum. While a significant increase in IgG concentration was seen on day 60 postnatum, no significant rise was measured in HCAbs at that age. Only post-colostrum IgG levels in calf serum correlated positively with IgG levels in mother colostrum. Directly after birth, newborn calves showed significantly higher NLR than their mothers. This indicates a pro-inflammatory nature of the calf immune response. The decrease of the NLR on day 60 postnatum may argue for the maturation of the calf immune response at this age.

Ancient and modern DNA reveal dynamics of domestication and cross-continental dispersal of the dromedary.

Dromedaries have been fundamental to the development of human societies in arid landscapes and for long-distance trade across hostile hot terrains for 3,000 y. Today they continue to be an important livestock resource in marginal agro-ecological zones. However, the history of dromedary domestication and the influence of ancient trading networks on their genetic structure have remained elusive. We combined ancient DNA sequences of wild and early-domesticated dromedary samples from arid regions with nuclear microsatellite and mitochondrial genotype information from 1,083 extant animals collected across the species' range. We observe little phylogeographic signal in the modern population, indicative of extensive gene flow and virtually affecting all regions except East Africa, where dromedary populations have remained relatively isolated. In agreement with archaeological findings, we identify wild dromedaries from the southeast Arabian Peninsula among the founders of the domestic dromedary gene pool. Approximate Bayesian computations further support the "restocking from the wild" hypothesis, with an initial domestication followed by introgression from individuals from wild, now-extinct populations. Compared with other livestock, which show a long history of gene flow with their wild ancestors, we find a high initial diversity relative to the native distribution of the wild ancestor on the Arabian Peninsula and to the brief coexistence of early-domesticated and wild individuals. This study also demonstrates the potential to retrieve ancient DNA sequences from osseous remains excavated in hot and dry desert environments.

Polymorphisms in MC1R and ASIP Genes are Associated with Coat Color Variation in the Arabian Camel.

Pigmentation in mammals is primarily determined by the distribution of eumelanin and pheomelanin, the ratio of which is mostly controlled by the activity of melanocortin 1 receptor (MC1R) and agouti signaling protein (ASIP) genes. Using 91 animals from 10 Arabian camel populations, that included the 4 predominant coat color phenotypes observed in the dromedary (light brown, dark brown, black, and white), we investigated the effects of the MC1R and ASIP sequence variants and identified candidate polymorphisms associated with coat color variation. In particular, we identified a single nucleotide polymorphism (SNP), found in the coding region of MC1R (901C/T), linked to the white coat color, whereas a 1-bp deletion (23delT/T) and a SNP (25G/A) in exon 2 of ASIP are associated with both black and dark-brown coat colors. Our results also indicate support that the light-brown coat color is likely the ancestral coat color for the dromedary. These sequence variations at the MC1R and ASIP genes represent the first documented evidence of candidate polymorphisms associated with Mendelian traits in the dromedary.

Beneficial probiotic bacteria prevalence in different lactating dromedary camel milk of Saudi Arabia.

Dromedary camel or Arabian camel (Camelus dromedarius) has great economic importance due to its milk and byproducts. Its milk has high nutrition along with healthy bacteria such as Lactic acid bacteria helpful in the fermentation process. The aim was to compare the probiotic bacteria from one week of lactating camel milk vs one year lactating camel milk to differentiate the potential probiotics. This study analyzed the microbiomes of one year lactating raw camel milk M1, M2 (A) (n = 10) and one week of lactating camel milk M3, M4 (B) (n = 10) through metagenomic analysis of 16S rRNA. In total, 276 species were found in two groups (A and B) and they shared 55 genes. Group B showed a higher number of species (2 2 0) than group A (56). The statistical data on functional annotations such as Card, COG, NOG and Swiss-prot revealed at least one or more contributions from this study sample database. The phylum Proteobacteria contributed largely up to 75 % in group B. In contrast, Ascomycota and Verrucomicrobia existed in higher quantity in group A than in group B and Firmicutes were slightly higher in group A than in group B. Actinobacteria were higher in group B whereas Bacteroidetes dominated in group A than group B. The potential probiotic bacteria found in camel milk including Enterococcus faecalis, Enterococcus faecium, Propionibacterium, Streptococcus thermophilus, Solibacillus silvestris and Akkermansia muciniphila. Despite the probiotic bacteria some pathogenic microbes also resided in the studied samples, hence it is strongly recommended proper sterilization before consumption. This proposed research is to get an efficient microbial consortium of beneficial bacteria and their functional roles.

Fluctuations of testosterone and cortisol levels in male dromedary camels in response to behavioral and management situations.

Background: Biostimulation is a management practice that improves the reproductive parameters, potentiates the desire, and improves the reproductive efficiency during the short breeding season in camels. Aim: This study aims to investigate the concurrent changes in hormonal profiles in response to management and behavioral situations on camel farms in the Eastern region of Saudi Arabia. Methods: A total of 10 male and 50 female camels were used in this study. The hormonal profile of male camels was evaluated weekly starting from December to August. Results: The results show that both serum testosterone and cortisol levels increased (p < 0.01) from December to March compared to April to August. A strong negative correlation was observed between testosterone levels and temperature (r = -0.81, p < 0.05), and a similarly robust negative correlation was found between cortisol levels and temperature (r = -0.83, p < 0.05). The dominant rutting males showed higher levels of testosterone than the submissive males. Serum testosterone levels increased (p < 0.01) in males out of rutting after hearing the sounds of other couples before and during mating. Conclusion: Hearing sounds emitted during mating increases the testosterone output, and improves the libido of male camels during the nonrutting period. It is important to keep two individually housed males for mating purposes. One male joins the herd alone in winter (winter rutter), and the other joins in spring (spring rutter), this could keep the libido extended rutting and improve the reproductive performance in camel herds.

Molecular detection of ruminal micro-flora and micro-fauna in Saudi Arabian camels: Effects of season and region.

This study investigated and explored the availability of micro-flora and micro-fauna in the ruminal contents of Arabian camel (Camelus dromedarius) from three different regions in Saudi Arabia along with two seasons. Samples were prepared and tested by conventional polymerase chain reaction (PCR). This study confirmed that the bacterial flora were dominating over other microbes. Different results of the availability of each microbe in each region and season were statistically analyzed and discussed. There was no significant effect of season on the micro-flora or micro-fauna however, the location revealed a positive effect with Ruminococcus flavefaciens (p < 0 0.03) in the eastern region. This study was the first to investigate the abundance of micro-flora and micro-fauna in the ruminal contents of camels of Saudi Arabia. This study underscores the significance of camel ruminal micro-flora and micro-fauna abundance, highlighting their correlation with both seasonality and geographic location. This exploration enhances our comprehension of camel rumination and digestion processes. The initial identification of these microbial communities serves as a foundational step, laying the groundwork for future in-depth investigations into camel digestibility and nutritional requirements.

Dissemination, virulence characteristic, antibiotic resistance determinants of emerging linezolid and vancomycin-resistant Enterococcus spp. in fish and crustacean.

Enterococci are emerging nosocomial pathogens. Their widespread distribution causes them to be food contaminants. Furthermore, Enterococci can colonize various ecological niches and diffuse into the food chain via contaminated animals and foods because of their remarkable tolerance to unfavorable environmental circumstances. Due to their potential dissemination to humans, antimicrobial-resistant Enterococci in fish are a worldwide health issue. This study characterized AMR, ARGs, VAGs, gelatinase activity, and biofilm formation in Enterococcus spp. recovered from fish and seafood and evaluated potential correlations. 54 Enterococcus spp. strains(32.73 %)were isolated from 165 samples (75 Oreochromis niloticus, 30 Argyrosomus regius, and 60 Shrimp), comprising 30 Enterococcus faecalis (55.6 %) and 24 Enterococcus faecium (44.4 %) with total 32.73 % (54/165), The maximum prevalence rate of Enterococcus spp. was observed in Nile tilapia (34/54; 63 %), followed by shrimp (14/54; 25.9 %) and Argyrosomus regius (6/54; 11.1 %). The maximum prevalence rate of E. faecalis was observed in Nile tilapia (22/30; 73.3 %), followed by shrimp (8/30; 26.7 %) with significant differences. The prevalence rate of E. faecium was observed in Nile tilapia (12/24; 50 %), followed by shrimp (6/24,25 %). E. faecium is only isolated from Argyrosomus regius (6/24,25 %). Isolates exhibited high resistance against both tetracycline (90.7 %) and erythromycin(88.9 %), followed by gentamycin (77.8 %), ciprofloxacin (74.1 %), levofloxacin (72.2 %), penicillin (44.4 %), vancomycin (37 %), and linezolid (20.4 %). 50 strains (92.6 %) exhibited resistance to more than two antibiotics, 5 strains (10 %) were XDR, and the remaining 45 strains (90 %) were classified as MDR. 92.6 % of the isolates had MARindices >0.2, indicating they originated in settings with a high risk of contamination. Additionally, ten ARGs were identified, with tet(M) 92.6 %, followed by erm(B) (88.9 %), aac(6')-Ie-aph(2″)-Ia(77.8 %), tet(K) (75.9 %), gyrA (74.1 %), blaZ (48.1 %), vanA (37 %), vanB (31.5 %), optrA (20.4 %), and catA(3.7 %). Biofilm formation and gelatinase activity were observed in 85.2 %, and 61.1 % of the isolates, respectively. A total of 11 VAGs were detected, with gelE as the most prevalent (83.3 %) followed by agg(79.6 %), pil (74.1 %), both sprE and asa1 (72.2 %), hyl (70.4 %), eps(68.5 %), EF3314 (57.4 %), ace (50 %), and cylA (35.2 %) with no detection of cylB. In conclusion, the emergence of linezolid-resistant -vancomycin-resistant enterococci recovered from Egyptian fish and shrimp, suggests that fish and seafood might participate a fundamental part in the emergence of antimicrobial resistance among humans.

Signatures of purifying selection and site-specific positive selection on the mitochondrial DNA of dromedary camels (Camelus dromedarius).

The two species of the Old World Camelini tribe, dromedary and Bactrian camels, show superior adaptability to the different environmental conditions they populate, e.g. desert, mountains and coastal areas, which might be associated with adaptive variations on their mitochondrial DNA. Here, we investigate signatures of natural selection in the 13-mitochondrial protein-coding genes of different dromedary camel populations from the Arabian Peninsula, Africa and southwest Asia. The full mitogenome sequences of 42 dromedaries, 38 domestic Bactrian, 29 wild Bactrian camels and 31 samples representing the New World Lamini tribe reveal species-wise genetic distinction among Camelidae family species, with no evidence of geographic distinction among dromedary camels. We observe gene-wide signals of adaptive divergence between the Old World and New World camels, with evidence of purifying selection among Old World camel species. Upon comparing the different Camelidae tribes, 27 amino acid substitutions across ten mtDNA protein-coding genes were found to be under positive selection, in which, 24 codons were defined to be under positive adaptive divergence between Old World and New World camels. Seven codons belonging to three genes demonstrated positive selection in dromedary lineage. A total of 89 codons were found to be under positive selection in Camelidae family based on investigating the impact of amino acid replacement on the physiochemical properties of proteins, including equilibrium constant and surrounding hydrophobicity. These mtDNA variants under positive selection in the Camelidae family might be associated with their adaptation to their contrasting environments.

Seasonal variations of vitamin A, D and E levels in serum of female camels (Camelus dromedarius) and their calves raised in five geographic regions of Saudi Arabia.

The aim of this study was to investigate the serum level of fat-soluble vitamins A, D and E in clinically healthy lactating female camel (Camelus dromedarius) and suckling calf > one-year-old during winter and summer seasons in five main regions of Saudi Arabia. 60 sera samples were collected and tested for vitamins A, D and E levels and the results were statistically analyzed. The statistical mean value of vitamin A was within the reported range but for D and E, there were minor variations. The effect of season was insignificant (p > 0.05) for vitamins A and E in the combined results of the dam and newborn together. This seasonal effect was highly significant in dam serum (p < 0.05). Region effect was significant for vitamin A in the northern area (p < 0.05) and for vitamin E in the southern region (p < 0.05). Correlations analysis revealed significant results in the season vs vitamin A and E p < 0.05. Mean values of vitamins A, D and E in dam and newborn did not observe significant variations however, in the season and regions there were significant variations which can be attributed to the climate difference, availability of balanced rations and camel management in each location of the five main regions of Saudi Arabia. There is a great need for further studies and the consequent development of supplementation programs and camel feed manufacturers awareness of such results is highly recommended.

Assessing genetic diversity and defining signatures of positive selection on the genome of dromedary camels from the southeast of the Arabian Peninsula.

Dromedary camels (Camelus dromedarius) are members of the Camelini tribe within the Camelidae family. They are distributed throughout North Africa, the Arabian Peninsula and Southeast Asia. This domestic species is characterized by its superior adaptability to the harsh desert environment. In this study, whole autosomal data of 29 dromedary samples from the Southeast Arabian Peninsula in Oman; 10 from Muscat, 14 from Al-Batinah, and 5 from Al-Sharqiya, were investigated to assess their genetic relationship and to define candidate signatures of positive selection. A minimal genetic distinction that separates Muscat dromedaries from the other two populations was observed, with a degree of genetic admixture between them. Using the de-correlated composite of multiple signals (DCMS) approach, a total of 47 candidate regions within the autosomes of these dromedary populations were defined with signatures of positive selection. These candidate regions harbor a total of 154 genes that are mainly associated with functional categories related to immune response, lipid metabolism and energy expenditure, optical and auditory functions, and long-term memory. Different functional genomic variants were called on the candidate regions and respective genes that warrant further investigation to find possible association with the different favorable phenotypes in dromedaries. The output of this study paves the way for further research efforts aimed at defining markers for use in genomic breeding programs, with the goal of conserving the genetic diversity of the species and enhancing its productivity.

Homogeneity of Arabian Peninsula dromedary camel populations with signals of geographic distinction based on whole genome sequence data.

Dromedary camels in the Arabian Peninsula distribute along different geographical and ecological locations, e.g. desert, mountains and coasts. Here, we are aiming to explore the whole genome sequence data of ten dromedary populations from the Arabian Peninsula to assess their genetic structure, admixture levels, diversity and similarity indices. Upon including reference dromedary and Bactrian camel populations from Iran and Kazakhstan, we characterise inter-species and geographic genetic distinction between the dromedary and the Bactrian camels. Individual-based alpha genetic diversity profiles are found to be generally higher in Bactrian camels than dromedary populations, with the exception of five autosomes (NC_044525.1, NC_044534.1, NC_044540.1, NC_044542.1, NC_044544.1) at diversity orders (q ≥ 2). The Arabian Peninsula camels are generally homogenous, with a small degree of genetic distinction correlating with three geographic groups: North, Central and West; Southwest; and Southeast of the Arabian Peninsula. No significant variation in diversity or similarity indices are observed among the different Arabian Peninsula dromedary populations. This study contributes to our understanding of the genetic diversity of Arabian Peninsula dromedary camels. It will help conserve the genetic stock of this species and support the design of breeding programmes for genetic improvement of favorable traits.

Genomic differences among strains of Corynebacterium cystitidis isolated from uterus of camels.

INTRODUCTION: Members of the Corynebacterium cystitidis species are usually isolated from kidney and urine of cow having pyelonephritis. Nevertheless, we have isolated Corynebacterium cystitidis for the first time from uterus of camels, extending the type of mammalian host for this species. Furthermore, it remains unknown whether there are significant genetic variations between strains isolated from different host species and anatomic sites. In this perspective, we investigated the genomic diversity of Corynebacterium cystitidis species, whose pan genome remain unexplored to date. METHODOLOGY: Thus, we sequenced and compared the genomes of five Corynebacterium cystitidis of camel origin and a public genome of cow associated Corynebacterium cystitidis. RESULTS: Results revealed open pan genome of 4,038 gene clusters and horizontal gene transfer played a role in the extensive genetic diversity. Further, we found an obvious distinction between cow and camel associated C. cystitidis via phylogenomic analysis and by average nucleotide identity value of 95% between the two distant lineages and > 99% within camel associated C. cystitidis strains. Moreover, our data supports the hypothesis that the gene repertoire of cow associated Corynebacterium cystitidis developed so as to become more adaptable to the urine milieu. These genetic potentials are specifically evident for genes required for benzoate breakdown, iron transport, citrate and alanine utilization. CONCLUSIONS: Our findings confirm the differentiation of strains into camel lineage and cow lineage. These different niches, comprising the uterus of camel and urinary tract of cow probably played a role in shaping the gene repertoire of strains.

Analyzing the roles of some species of arthropods in the transmission of the Middle East respiratory syndrome coronavirus.

BACKGROUND: The Middle East Respiratory Syndrome coronavirus (MERS-CoV) is still listed on the WHO Research and Development Blueprint of emerging pathogens. Dromedary camels remain the only known animal reservoir of the virus. The animal-to-animal as well as the animal-to-human transmission in the MERS-CoV cycles were reported. However, many aspects of these transmission chains are not well studied. One of these directions is the potential roles of various species of arthropods in the transmission of the virus. OBJECTIVES: The main goal of the current work was to study the roles of several species of arthropods in the transmission of MERS-CoV. METHODOLOGY: To achieve this goal, we identified some MERS-CoV naturally infected dromedary camel populations. We conducted a longitudinal study among these animals for more than 2 months. This was done by repeated testing of nasal swabs biweekly from some selected animals in this population for the presence of MERS-CoV-RNAs by real-time PCR. During the duration of this study, we collected several species of arthropods (Culicoides, Stomoxys, Musca domestica and some Culex species) that shared the habitat and were circulating in this farm during this longitudinal study. RESULTS: Our results showing, despite the detection of the viral RNAs in some animals throughout this study, none of the examined species of arthropods tested positive for the viral RNA. CONCLUSIONS: These results are suggesting that at least the tested species of arthropods may not play roles in the transmission of MERS-CoV. However, more large-scale studies are required to explore any potential roles of arthropods in the transmission cycle of MERS-CoV.

Flow Cytometric Analysis of Leukocyte Populations in the Lung Tissue of Dromedary Camels.

Respiratory tract infections are among the most common infections in dromedary camels, with a high impact on animal health, production, and welfare. Tissue-specific distribution of immune cells is one of the important factors that influence the nature and outcome of the immune response to pathogens. Several protocols have recently been described for the flow cytometric analysis of immune cells in the lung tissue of several species. However, no such protocol currently exists for dromedary camels. The aim of the present study was, therefore, to establish a flow cytometric protocol for the identification of immune cell populations in the camel lung tissue and the evaluation of some of their phenotypic and functional properties. Combined staining of camel lung leukocytes with monoclonal antibodies to the pan-leukocyte marker CD45 and the myeloid cell marker CD172a allowed the identification of myeloid cells (CD45+CD172a+) and lymphoid cells (CD45+CD172a-) in the lung of healthy camels. The cell adhesion molecules CD11a and CD18 were found in a higher abundance on myeloid cells compared to lymphoid cells. Based on their differential expression of the LPS receptor CD14, macrophages (CD172a+CD14high cells) were identified as the most abundant immune cell population in the camel lung tissue. In contrast to their dominance in camel peripheral blood, granulocytes (CD172a+CD14low) presented only a minor population in the lung tissue. The higher frequency of γδ T cells in the lung tissue than in peripheral blood suggests a role for these cells in the pulmonary immune system. Flow cytometric analysis of bacterial phagocytosis and ROS production upon bacterial stimulation revealed high antimicrobial activity of camel lung phagocytes, which was comparable with the antimicrobial activity of blood granulocytes. Comparative analysis of immune cell distribution between the cranial and caudal lobes of the camel lung revealed a higher frequency of granulocytes and a lower frequency of macrophages in the cranial compared to the caudal lung lobe. In addition, the higher frequency of cells expressing the M2 macrophage marker CD163 in the caudal lung tissue, with a slightly higher fraction of MHCII-positive cells (M1 phenotype) in the cranial lung tissue, may suggest the distribution of different macrophage subtypes in the different lobes of the camel lung. Such differences between lung lobes could influence the effectiveness of the immune response to infection or vaccination with respiratory pathogens. Collectively, the present study identified some similarities and differences between camels and other farm animals regarding the distribution of the main immune cell populations in their lungs. Further studies are required for comprehensive immunophenotyping of the cellular pulmonary immune system in camels.

Refining the Camelus dromedarius Myostatin Gene Polymorphism through Worldwide Whole-Genome Sequencing.

Myostatin (MSTN) is a highly conserved negative regulator of skeletal muscle in mammals. Inactivating mutations results in a hyper-muscularity phenotype known as "double muscling" in several livestock and model species. In Camelus dromedarius, the gene structure organization and the sequence polymorphisms have been previously investigated, using Sanger and Next-Generation Sequencing technologies on a limited number of animals. Here, we carried out a follow-up study with the aim to further expand our knowledge about the sequence polymorphisms at the myostatin locus, through the whole-genome sequencing data of 183 samples representative of the geographical distribution range for this species. We focused our polymorphism analysis on the ±5 kb upstream and downstream region of the MSTN gene. A total of 99 variants (77 Single Nucleotide Polymorphisms and 22 indels) were observed. These were mainly located in intergenic and intronic regions, with only six synonymous Single Nucleotide Polymorphisms in exons. A sequence comparative analysis among the three species within the Camelus genus confirmed the expected higher genetic distance of C. dromedarius from the wild and domestic two-humped camels compared to the genetic distance between C. bactrianus and C. ferus. In silico functional prediction highlighted: (i) 213 differential putative transcription factor-binding sites, out of which 41 relative to transcription factors, with known literature evidence supporting their involvement in muscle metabolism and/or muscle development; and (ii) a number of variants potentially disrupting the canonical MSTN splicing elements, out of which two are discussed here for their potential ability to generate a prematurely truncated (inactive) form of the protein. The distribution of the considered variants in the studied cohort is discussed in light of the peculiar evolutionary history of this species and the hypothesis that extremely high muscularity, associated with a homozygous condition for mutated (inactivating) alleles at the myostatin locus, may represent, in arid desert conditions, a clear metabolic disadvantage, emphasizing the thermoregulatory and water availability challenges typical of these habitats.