A sero-epidemiological analysis of Coxiella burnetii infection and its risk factors in livestock from Addis Ababa, Adama, and Modjo abattoirs and pastoral areas of Oromia, Ethiopia.

BACKGROUND: Coxiella burnetii is causing infections in both humans and animals, resulting in Q fever and Coxiellosis, respectively. Information on the occurrence of C. burnetii infection is scarce in Ethiopia. This study estimated the sero-prevalence of C. burnetii infection and associated risk factors in four common livestock species from Addis Ababa, Adama, and Modjo abattoirs and pastoral areas of Oromia, Ethiopia. RESULTS/PRINCIPAL FINDINGS: Sera samples were analyzed for the presence of anti-C. burnetii antibodies using an indirect Enzyme Linked Immunosorbent Assay kit. Out of the 4140 serum samples tested, 777 (18.77%; 95% CI: 17.59, 19.99) were found positive for C. burnetii. The sero-prevalence estimate was 27.17% at Addis Ababa abattoir, 19.41% at Adama abattoir, 19.13% at Modjo abattoir and 12.1% in animals tested from pastoral areas. Sera analysis at the animal species level showed that cattle exhibited the lowest sero-prevalence estimate (11.83%; 95% CI, 10.27-13.53%), while the highest was observed in camels (28.39%; 95% CI, 25.16-31.80%). The sero-prevalence estimate was 21.34% (95% CI, 18.86-23.99%) in goats and 20.17% (95% CI, 17.49-23.07%) in sheep. The results of multivariable logistic regression analysis showed that species, age, sex of animals and tick infestation were important risk factors for C. burnetii infection. The odds of infection were 3.22 times higher in camels and almost twice as high in goats and sheep compared to cattle. Adult animals were infected more likely (OR = 3.23) than young ones. Interestingly, a significant difference was observed in the sero-prevalence of infection between animals that were infested with ticks (OR = 16.32) and those which were tick-free. CONCLUSION: This study provides valuable insights into the sero-epidemiology of C. burnetii infection in four common livestock species at major abattoirs and pastoral areas of Ethiopia. The findings highlight the need for further studies and implementing surveillance and biosecurity measures to prevent the spread of the disease in both humans and livestock to safeguard the economical and public health aspects.

Molecular screening and genetic diversity of tick-borne pathogens associated with dogs and livestock ticks in Egypt.

BACKGROUND: The Middle East and North Africa (MENA) offer optimal climatic conditions for tick reproduction and dispersal. Research on tick-borne pathogens in this region is scarce. Despite recent advances in the characterization and taxonomic explanation of various tick-borne illnesses affecting animals in Egypt, no comprehensive examination of TBP (tick-borne pathogen) statuses has been performed. Therefore, the present study aims to detect the prevalence of pathogens harbored by ticks in Egypt. METHODOLOGY/PRINCIPAL FINDINGS: A four-year PCR-based study was conducted to detect a wide range of tick-borne pathogens (TBPs) harbored by three economically important tick species in Egypt. Approximately 86.7% (902/1,040) of the investigated Hyalomma dromedarii ticks from camels were found positive with Candidatus Anaplasma camelii (18.8%), Ehrlichia ruminantium (16.5%), Rickettsia africae (12.6%), Theileria annulata (11.9%), Mycoplasma arginini (9.9%), Borrelia burgdorferi (7.7%), Spiroplasma-like endosymbiont (4.0%), Hepatozoon canis (2.4%), Coxiella burnetii (1.6%) and Leishmania infantum (1.3%). Double co-infections were recorded in 3.0% (27/902) of Hy. dromedarii ticks, triple co-infections (simultaneous infection of the tick by three pathogen species) were found in 9.6% (87/902) of Hy. dromedarii ticks, whereas multiple co-infections (simultaneous infection of the tick by ≥ four pathogen species) comprised 12% (108/902). Out of 1,435 investigated Rhipicephalus rutilus ticks collected from dogs and sheep, 816 (56.9%) ticks harbored Babesia canis vogeli (17.1%), Rickettsia conorii (16.2%), Ehrlichia canis (15.4%), H. canis (13.6%), Bo. burgdorferi (9.7%), L. infantum (8.4%), C. burnetii (7.3%) and Trypanosoma evansi (6.6%) in dogs, and 242 (16.9%) ticks harbored Theileria lestoquardi (21.6%), Theileria ovis (20.0%) and Eh. ruminantium (0.3%) in sheep. Double, triple, and multiple co-infections represented 11% (90/816), 7.6% (62/816), and 10.3% (84/816), respectively in Rh. rutilus from dogs, whereas double and triple co-infections represented 30.2% (73/242) and 2.1% (5/242), respectively in Rh. rutilus from sheep. Approximately 92.5% (1,355/1,465) of Rhipicephalus annulatus ticks of cattle carried a burden of Anaplasma marginale (21.3%), Babesia bigemina (18.2%), Babesia bovis (14.0%), Borrelia theleri (12.8%), R. africae (12.4%), Th. annulata (8.7%), Bo. burgdorferi (2.7%), and Eh. ruminantium (2.5%). Double, triple, and multiple co-infections represented 1.8% (25/1,355), 11.5% (156/1,355), and 12.9% (175/1,355), respectively. The detected pathogens' sequences had 98.76-100% similarity to the available database with genetic divergence ranged between 0.0001 to 0.0009% to closest sequences from other African, Asian, and European countries. Phylogenetic analysis revealed close similarities between the detected pathogens and other isolates mostly from African and Asian countries. CONCLUSIONS/SIGNIFICANCE: Continuous PCR-detection of pathogens transmitted by ticks is necessary to overcome the consequences of these infection to the hosts. More restrictions should be applied from the Egyptian authorities on animal importations to limit the emergence and re-emergence of tick-borne pathogens in the country. This is the first in-depth investigation of TBPs in Egypt.

Molecular epidemiology and associated risk factors of Anaplasma marginale in camels and possible co-infections.

Anaplasma spp. is an important pathogen that affects a wide range of animals, including camels. The current study aimed to assess the prevalence of six Anaplasma spp. in 400 camels from Ismailia, Suez, and Sharkia governorates in northern Egypt, as well as their associated risk factors and possible coinfections. Blood and fecal samples were examined using bacterial culture, the vitek2 system, and PCR. Genetic divergence among Anaplasma marginale (A. marginale) isolates was characterized using the msp4 gene. The overall prevalence of A. marginale was 19.5%. Sequencing analysis confirmed the PCR results, and a single A. marginale genotype was recognized by msp4 sequencing. The phylogenetic tree indicated that the study A. marginale isolates clustered together and were close to Egyptian A. marginale identified from buffalo (OP142725 and OP142726). Age, sex, housing type, tick infestation, body conditions, and tick control factors were significantly associated with camel anaplasmosis using a logistic regression model (odds ratio >1, P < 0.05). Multivariate logistic regression analysis revealed that the infection was 2.03, 1.9, 2.6, 1.9, and 1.8 times higher in females, semi-enclosed housing, ages >5 years, tick infestation, and emaciated camels. The risk of infection due to a tick control factor increased by 4.4 and 2.6 times when no control was applied or with irregular control, respectively. This is the first molecular report of A. marginale infection in camels in Ismailia, Suez, and Sharkia in northern Egypt, indicating a moderate prevalence of A. marginale and the involvement of multiple bacterial infections, mainly Escherichia coli and Salmonella spp. Thus, it is necessary to develop effective management and control for camel anaplasmosis.

Tissue-specific localization of tick-borne pathogens in ticks collected from camels in Kenya: insights into vector competence.

Background: Tick-borne pathogen (TBP) surveillance studies often use whole-tick homogenates when inferring tick-pathogen associations. However, localized TBP infections within tick tissues (saliva, hemolymph, salivary glands, and midgut) can inform pathogen transmission mechanisms and are key to disentangling pathogen detection from vector competence. Methods: We screened 278 camel blood samples and 504 tick tissue samples derived from 126 camel ticks sampled in two Kenyan counties (Laikipia and Marsabit) for Anaplasma, Ehrlichia, Coxiella, Rickettsia, Theileria, and Babesia by PCR-HRM analysis. Results: Candidatus Anaplasma camelii infections were common in camels (91%), but absent in all samples from Rhipicephalus pulchellus, Amblyomma gemma, Hyalomma dromedarii, and Hyalomma rufipes ticks. We detected Ehrlichia ruminantium in all tissues of the four tick species, but Rickettsia aeschlimannii was only found in Hy. rufipes (all tissues). Rickettsia africae was highest in Am. gemma (62.5%), mainly in the hemolymph (45%) and less frequently in the midgut (27.5%) and lowest in Rh. pulchellus (29.4%), where midgut and hemolymph detection rates were 17.6% and 11.8%, respectively. Similarly, in Hy. dromedarii, R. africae was mainly detected in the midgut (41.7%) but was absent in the hemolymph. Rickettsia africae was not detected in Hy. rufipes. No Coxiella, Theileria, or Babesia spp. were detected in this study. Conclusions: The tissue-specific localization of R. africae, found mainly in the hemolymph of Am. gemma, is congruent with the role of this tick species as its transmission vector. Thus, occurrence of TBPs in the hemolymph could serve as a predictor of vector competence of TBP transmission, especially in comparison to detection rates in the midgut, from which they must cross tissue barriers to effectively replicate and disseminate across tick tissues. Further studies should focus on exploring the distribution of TBPs within tick tissues to enhance knowledge of TBP epidemiology and to distinguish competent vectors from dead-end hosts.

Bartonella species in dromedaries and ruminants from Lower Shabelle and Benadir regions, Somalia.

BACKGROUND: Bartonellosis, caused by bacteria of the genus Bartonella, is a zoonotic disease with several mammalian reservoir hosts. In Somalia, a country heavily reliant on livestock, zoonotic diseases pose significant public health and economic challenges. To the best of our knowledge, no study has been performed aiming to verify the occurrence of Bartonella spp. in Somalia. This study investigated the occurrence and molecular characterization of Bartonella in dromedary (Camelus dromedarius, Linnaeus, 1758), cattle, sheep, and goats from Somalia. MATERIALS AND METHODS: 530 blood samples were collected from various animals (155 dromedary, 199 goat, 131 cattle, and 45 sheep) in Benadir and Lower Shabelle regions. DNA was extracted for molecular analysis, and a qPCR assay targeting the NADH dehydrogenase gamma subunit (nuoG) gene was used for Bartonella screening. Positive samples were also subjected to PCR assays targeting seven molecular markers including: nuoG, citrate synthase gene (gltA), RNA polymerase beta-subunit gene (rpoB), riboflavin synthase gene (ribC), 60 kDa heat-shock protein gene (groEL), cell division protein gene (ftsZ), and pap31 and qPCR targeting the 16-23S rRNA internal transcribed spacer (ITS) followed by Sanger sequencing, BLASTn and phylogenetic analysis. RESULTS: Out of 530 tested animals, 5.1% were positive for Bartonella spp. by the nuoG qPCR assay. Goats showed the highest Bartonella occurrence (17/199, 8.5%), followed by sheep (6/44, 6.8%), cattle (4/131, 3.1%), and dromedary (1/155, 1.9%). Goats, sheep, and cattle had higher odds of infection compared to dromedary. Among nuoG qPCR-positive samples, 11.1%, 14.8%, 11.1%, and 25.9% were positive in PCR assays based on nuoG, gltA, and pap31 genes, and in the qPCR based on the ITS region, respectively. On the other hand, nuoG qPCR-positive samples were negative in the PCR assays targeting the ribC, rpoB, ftsZ, and groEL genes. While Bartonella bovis sequences were detected in cattle (nuoG and ITS) and goats (gltA), Bartonella henselae ITS sequences were detected in dromedary, goat, and sheep. Phylogenetic analysis placed gltA Bartonella sequence from a goat in the same clade of B. bovis. CONCLUSION: The present study showed, for the first time, molecular evidence of Bartonella spp. in dromedary and ruminants from Somalia and B. henselae in sheep and goats globally. These findings contribute valuable insights into Bartonella spp. occurrence in Somali livestock, highlighting the need for comprehensive surveillance and control measures under the One Health approach.

Distribution characteristics of gastric mucosal colonizing microorganisms in different glandular regions of Bactrian camels and their relationship with local mucosal immunity.

Bactrian camels inhabiting desert and semi-desert regions of China are valuable animal models for studying adaptation to desert environments and heat stress. In this study, 16S rRNA technology was employed to investigate the distribution characteristics and differences of mucosal microorganisms in the anterior gland area, posterior gland area, third gland area, cardia gland area, gastric fundic gland area and pyloric gland area of 5-peak adult healthy Bactrian camels. We aimed to explore the possible reasons for the observed microbial distribution from the aspects of histological structure and mucosal immunity. Bacteroides and Fibrobacteria accounted for 59.54% and 3.22% in the gland area, respectively, and 52.37% and 1.49% in the wrinkled stomach gland area, respectively. The gland area showed higher abundance of Bacteroides and Fibrobacteria than the wrinkled stomach gland area. Additionally, the anterior gland area, posterior gland area, third gland area, and cardia gland area of Bactrian camels mainly secreted acidic mucus, while the gastric fundic gland area mainly secreted neutral mucus and the pyloric region mainly secreted a mixture of acidic and neutral mucus. The results of immunohistochemistry techniques demonstrated that the number of IgA+ cells in the anterior glandular area, posterior glandular area, third glandular area, and cardia gland area was significantly higher than that in the fundic and pyloric gland area (p < 0.05), and the difference in IgA+ between the fundic and pyloric gland area was not significant (p > 0.05). The study revealed a large number of bacteria that can digest and degrade cellulose on the mucosa of the gastric gland area of Bactrian camels. The distribution of IgA+ cells, the structure of the mucosal tissue in the glandular region, and the composition of the mucus secreted on its surface may have a crucial influence on microbial fixation and differential distribution.

Coxiella burnetii serostatus in dromedary camels (Camelus dromedarius) is associated with the presence of C. burnetii DNA in attached ticks in Laikipia County, Kenya.

AIMS: Q fever is a globally distributed, neglected zoonotic disease of conservation and public health importance, caused by the bacterium Coxiella burnetii. Coxiella burnetii normally causes subclinical infections in livestock, but may also cause reproductive pathology and spontaneous abortions in artiodactyl species. One such artiodactyl, the dromedary camel (Camelus dromedarius), is an increasingly important livestock species in semi-arid landscapes. Ticks are naturally infected with C. burnetii worldwide and are frequently found on camels in Kenya. In this study, we assessed the relationship between dromedary camels' C. burnetii serostatus and whether the camels were carrying C. burnetii PCR-positive ticks in Kenya. We hypothesized that there would be a positive association between camel seropositivity and carrying C. burnetii PCR-positive ticks. METHODS AND RESULTS: Blood was collected from camels (N = 233) from three herds, and serum was analysed using commercial ELISA antibody test kits. Ticks were collected (N = 4354), divided into pools of the same species from the same camel (N = 397) and tested for C. burnetii and Coxiella-like endosymbionts. Descriptive statistics were used to summarize seroprevalence by camel demographic and clinical variables. Univariate logistic regression analyses were used to assess relationships between serostatus (outcome) and tick PCR status, camel demographic variables, and camel clinical variables (predictors). Camel C. burnetii seroprevalence was 52%. Across tick pools, the prevalence of C. burnetii was 15% and Coxiella-like endosymbionts was 27%. Camel seropositivity was significantly associated with the presence of a C. burnetii PCR-positive tick pool (OR: 2.58; 95% CI: 1.4-5.1; p = 0.0045), increasing age class, and increasing total solids. CONCLUSIONS: The role of ticks and camels in the epidemiology of Q fever warrants further research to better understand this zoonotic disease that has potential to cause illness and reproductive losses in humans, livestock, and wildlife.

Molecular diagnosis for camel raw milk microbiota.

The existence of diverse microbes in unprocessed camel milk poses a significant threat to the well-being of a large population, especially infants and toddlers. The objective of this study was to ascertain the existence of microorganisms in unprocessed raw camel milk by employing a molecular-based technique in combination with a histological examination of bacteria. The identification of microbial species was achieved by employing PCR amplification and sequencing of 16s rRNA gene fragments. Various micorganisms found includes the probiotic Lactobacillus species, Staphylococcus succinic, Macrococcus casealyticus, Bacillus cohnii, and Salinicoccus kunmingensis. To prevent microbial contamination in raw milk, it is necessary to adequately heat or pasteurise the milk and to wash and sterilise the udder before milking the camel. This is because raw milk contains microbes that cause multiple diseases. Moreover, in the current era of the COVID-19 pandemics, ensuring proper sanitary conditions in milk and its derivatives might potentially mitigate the transmission of various diseases among consumers shortly. Keywords: camel, microbiota, 16s rRNA gene, PCR.

Molecular detection and diversity of tick-borne rickettsial pathogens in ticks collected from camel (Camelus dromedarius) in Upper Egypt.

Tick-borne rickettsial pathogens pose significant threats to public and animal health. In Upper Egypt, limited information exists regarding the prevalence and diversity of such tick-borne pathogens. Therefore, this study aimed to conduct a comprehensive investigation to elucidate the presence and variety of tick-borne rickettsial pathogens in Upper Egyptian camels. Our results revealed a prevalence of 2.96 % for Anaplasma marginale and 0.34 % for Candidatus Anaplasma camelii among Hyalomma ticks. However, Ehrlichia spp. weren't detected in our study. The identification of Ca. A. camelii in H. dromedari ticks was documented for the first time, suggesting a potential mode of transmission in camels. Notably, this study marks the first documentation of Rickettsia aeschlimannii with a prevalence of 6.06 % in the study area. Furthermore, we detected Coxiella burnetii in a prevalence of 8.08 % in Hyalomma ticks, indicating a potential risk of Q fever transmission. Molecular techniques results were confirmed by sequencing and phylogenetic analysis and provided valuable insights into the epidemiology of these pathogens, revealing their diversity. This study is vital in understanding tick-borne rickettsial pathogens' prevalence, distribution, and transmission dynamics in Upper Egypt. In conclusion, our findings emphasize the importance of continued research to enhance our understanding of the epidemiology and impact of these pathogens on both animal and human populations.

Integrated omics analysis reveals the immunologic characteristics of cystic Peyer's patches in the cecum of Bactrian camels.

Bactrian camels have specific mucosa-associated lymphoid tissue (MALT) throughout the large intestine, with species-unique cystic Peyer's patches (PPS) as the main type of tissue. However, detailed information about the molecular characteristics of PPS remains unclear. This study applied a transcriptomic analysis, untargeted metabolomics, and 16S rDNA sequencing to compare the significant differences between PPS and the adjacent normal intestine tissues (NPPS) during the healthy stage of three young Bactrian camels. The results showed that samples from PPS could be easily differentiated from the NPPS samples based on gene expression profile, metabolites, and microbial composition, separately indicated using dimension reduction methods. A total of 7,568 up-regulated and 1,266 down-regulated differentially expressed genes (DEGs) were detected, and an enrichment analysis found 994 DEGs that participated in immune-related functions, and a co-occurance network analysis identified nine hub genes (BTK, P2RX7, Pax5, DSG1, PTPN2, DOCK11, TBX21, IL10, and HLA-DOB) during multiple immunologic processes. Further, PPS and NPPS both had a similar pattern of most compounds among all profiles of metabolites, and only 113 differentially expressed metabolites (DEMs) were identified, with 101 of these being down-regulated. Deoxycholic acid (DCA; VIP = 37.96, log2FC = -2.97, P = 0), cholic acid (CA; VIP = 13.10, log2FC = -2.10, P = 0.01), and lithocholic acid (LCA; VIP = 12.94, log2FC = -1.63, P = 0.01) were the highest contributors to the significant dissimilarities between groups. PPS had significantly lower species richness (Chao1), while Firmicutes (35.92% ± 19.39%), Bacteroidetes (31.73% ± 6.24%), and Proteobacteria (13.96% ± 16.21%) were the main phyla across all samples. The LEfSe analysis showed that Lysinibacillus, Rikenellaceae_RC9_gut_group, Candidatus_Stoquefichus, Mailhella, Alistipes, and Ruminococcaceae_UCG_005 were biomarkers of the NPPS group, while Escherichia_Shigella, Synergistes, Pyramidobacter, Odoribacter, Methanobrevibacter, Cloacibacillus, Fusobacterium, and Parabacteroides were significantly higher in the PPS group. In the Procrustes analysis, the transcriptome changes between groups showed no significant correlations with metabolites or microbial communities, whereas the alteration of metabolites significantly correlated with the alteration of the microbial community. In the co-occurrence network, seven DEMs (M403T65-neg, M329T119-neg, M309T38-neg, M277T42-2-neg, M473T27-neg, M747T38-1-pos, and M482t187-pos) and 14 genera (e.g., Akkermansia, Candidatus-Stoquefichus, Caproiciproducens, and Erysipelatoclostridium) clustered much more tightly, suggesting dense interactions. The results of this study provide new insights into the understanding of the immune microenvironment of the cystic PPS in the cecum of Bactrian camels.

The prevalence of Q fever in the Eastern Mediterranean region: a systematic review and meta-analysis.

OBJECTIVES: Q fever, caused by the bacterium, is a major zoonotic disease around the world. This disease is common in the Eastern Mediterranean region; therefore, we conducted the first systematic review and meta-analysis on its prevalence in humans, animals, and ticks in the Eastern Mediterranean region. METHODS: Major Iranian and international databases were searched from 2000 to 2021. We extracted the prevalence of Q fever in blood samples from animals and milk samples from animals, ticks, and humans as the main outcome. We reported the prevalence of seropositivity and molecular positivity as point estimates and 95% confidence intervals (CIs). RESULTS: In this review, 112 papers were identified. The overall seroprevalence of Q fever was 22.4% (95% CI, 19.8 to 25.1). The pooled prevalence of Q fever in ticks was 17.5% (95% CI, -1.3 to 36.4). The prevalence was 25.5% (95% CI, 16.1 to 34.9) in humans. The prevalence of Q fever in animal blood samples from goats, sheep, camels, cattle, cats, dogs, horses, and buffalo were 28.1%, 25.1%, 25.0%, 20.1%, 9.8%, 8.4%, 6.5%, and 6.3%, respectively. Furthermore, the prevalence of Q fever in milk samples of animals was higher in cattle (20.3%) than in sheep (20.0%), goats (16.4%), and camels (3.3%). CONCLUSIONS: Coxiella burnetii infections are common in humans and in a wide range of animal species, but they are still not recognized in many countries in the Eastern Mediterranean region, thus presenting a significant threat to human and animal health in the region.

Epidemiology and genetic characteristics of tick-borne bacteria in dromedary camels of the world.

This review presents updated knowledge on the main tick-borne bacteria infecting one-humped camels (Camelus dromedarius) around the world. Camels are increasingly the subject of several scientific investigations, showing that they are receptive and carriers of several zoonotic bacteria. An appraisal is also given of the relative public health importance of these bacterial infections according to One Health concept. Microscopic, serologic and molecular findings are appropriately generated in order to exploit epidemiological data, and phylogeographic specificities associated to each vector-borne bacterium. Indeed, camels and their ticks harbour similar species and genotypes of pathogenic bacteria commonly identified in other animals, e.g., Anaplasma spp.,Ehrlichia spp., Borrelia spp., Rickettsia spp., Coxiella burnetii, Bartonella spp. and hemotrophic mycoplasmas. This evidence suggests an epidemiological role of camels in the spread of these pathogens in their natural habitats. However, these infections are commonly asymptomatic in camels resulting in underestimation of the impact of these infections. Furthermore, camels have recently been proven to have their own specific unclassified strains, such as Candidatus Anaplasma camelii and Candidatus Bartonella camelii, implying that possible interactions may lead to the emergence of pathogenic and zoonotic bacteria. In camel-rearing areas of the world, spatial and temporal spread of these infections, due to climatic and ecological changes and human activities such as development projects and urbanization, is expected. Hence the data presented herein provides a basis for strategic frameworks for the research and the development of novel diagnosis and control strategies worldwide, which are needed to protect camels, other livestock, and people in contact with dromedaries from threats that arthropod-borne pathogens can pose.

Functional and phylogenetic analyses of camel rumen microbiota associated with different lignocellulosic substrates.

Rumen microbiota facilitates nutrition through digestion of recalcitrant lignocellulosic substrates into energy-accessible nutrients and essential metabolites. Despite the high similarity in rumen microbiome structure, there might be distinct functional capabilities that enable different ruminant species to thrive on various lignocellulosic substrates as feed. Here, we applied genome-centric metagenomics to explore phylogenetic diversity, lignocellulose-degrading potential and fermentation metabolism of biofilm-forming microbiota colonizing 11 different plant substrates in the camel rumen. Diversity analysis revealed significant variations in the community of rumen microbiota colonizing different substrates in accordance with their varied physicochemical properties. Metagenome reconstruction recovered genome sequences of 590 bacterial isolates and one archaeal lineage belonging to 20 microbial phyla. A comparison to publicly available reference genomes and rumen metagenome-assembled genomes revealed that most isolates belonged to new species with no well-characterized representatives. We found that certain low abundant taxa, including members of Verrucomicrobiota, Planctomycetota and Fibrobacterota, possessed a disproportionately large number of carbohydrate active enzymes per Mb of genome, implying their high metabolic potential to contribute to the rumen function. In conclusion, we provided a detailed picture of the diversity and functional significance of rumen microbiota colonizing feeds of varying lignocellulose composition in the camel rumen. A detailed analysis of 591 metagenome-assembled genomes revealed a network of interconnected microbiota and highlighted the key roles of certain taxonomic clades in rumen function, including those with minimal genomes (e.g., Patescibacteria). The existence of a diverse array of gene clusters encoding for secondary metabolites unveiled the specific functions of these biomolecules in shaping community structure of rumen microbiota.

Pathological insights into camel mastitis.

Camel is a multipurpose animal bred to produce milk, meat, and transport and serves as a financial reserve for pastoralists by playing an important role in social prestige and prosperity. Camel milk is a good substitute for human milk because of its exceptional nutritional properties. Udder infections are considered one of the main limitations to camel farming. In recent decades, the disease has been reported by numerous camel-producing countries in Africa and Asia, such as Egypt, Somalia, Sudan, Kenya, Saudi Arabia, and Iraq. The current review provides an overview of the forms of camel mastitis, which can be clinical mastitis characterized by hardening and swelling of the breast, pain on palpation, and visible changes in the colour and texture of the milk or subclinical mastitis refers to the presence of inflammation with no obvious signs and it can be detected by indirect tests such as the California mastitis test (CMT), somatic cell count (SCC), and microbiological examination. Major pathogens of camel mastitis are Staphylococcus aureus, Streptococcus agalactiae, Escherichia coli, and Corynebacterium bovis. Regarding the risk factors for camel mastitis, this study provides an overview of the most important risk factors such as severe tick infestation, teat injuries, hygienic milking protocols, and physiological disorders causing mastitis. The use of indirect tests and bacteriological studies as diagnostic tools and their values for detecting camel mastitis will also be reviewed. Based on the above, further epidemiological studies on camel mastitis are needed to have solid scientific data on disease transmission, pathogen characterization, other possible risk factors or diagnostic methods, and the impact of the disease on public health. Proper control strategies should be adopted through early diagnosis, treatment and by avoiding potential risk factors to get good quality milk from camels.

The effects of genital myiasis on the diversity of the vaginal microbiota in female Bactrian camels.

BACKGROUND: Genital myasis is one of the most important diseases that affects the reproductive organs of Bactrian camels in which can cause serious mechanical damage to the vaginal tissue. The accumulation of bacteria in the vagina of female camels can affect their health and reproductive ability. The effect of this damage is commonly manifested in the vaginal flora and vaginal mucosal immune system. Therefore, this investigation is a study of the diversity of the vaginal flora and the differences between healthy Bactrian camels and those suffering from genital myiasis. RESULTS: Vaginal microbiota samples were collected from two groups of female Bactrian camels of the same age. An Illumina MiSeq was used to sequence the 16S rRNA V3-V4 hypervariable sequence in the samples. The results showed that the vaginal microflora of the infected camels had a significantly greater operational taxonomic unit (OTU) value. According to the assessment of the alpha diversity index and the vaginal pH, the diversity index of the infected camel flora was higher than that of the normal camel flora, and the vaginal pH was lower than that of the normal camels (p < 0.01). There were no significant differences between the two groups in the abundance of dominant genera in the Bactrian camel vagina (P > 0.05), indicating that the certain stability is maintained. CONCLUSIONS: Overall, this comparison revealed the differences and similarities between the vaginal microbiota of Bactrian camels in various health statues. In addition, these data provide a reference point for understanding the types of bacteria that cause genital myiasis affecting the healthy development of Bactrian camels.

Fibrolytic rumen bacteria of camel and sheep and their applications in the bioconversion of barley straw to soluble sugars for biofuel production.

Lignocellulosic biomass such as barley straw is a renewable and sustainable alternative to traditional feeds and could be used as bioenergy sources; however, low hydrolysis rate reduces the fermentation efficiency. Understanding the degradation and colonization of barley straw by rumen bacteria is the key step to improve the utilization of barley straw in animal feeding or biofuel production. This study evaluated the hydrolysis of barley straw as a result of the inoculation by rumen fluid of camel and sheep. Ground barley straw was incubated anaerobically with rumen inocula from three fistulated camels (FC) and three fistulated sheep (FR) for a period of 72 h. The source of rumen inoculum did not affect the disappearance of dry matter (DMD), neutral detergent fiber (NDFD). Group FR showed higher production of glucose, xylose, and gas; while higher ethanol production was associated with cellulosic hydrolysates obtained from FC group. The diversity and structure of bacterial communities attached to barley straw was investigated by Illumina Mi-Seq sequencing of V4-V5 region of 16S rRNA genes. The bacterial community was dominated by phylum Firmicutes and Bacteroidetes. The dominant genera were RC9_gut_group, Ruminococcus, Saccharofermentans, Butyrivibrio, Succiniclasticum, Selenomonas, and Streptococcus, indicating the important role of these genera in lignocellulose fermentation in the rumen. Group FR showed higher RC9_gut_group and group FC revealed higher Ruminococcus, Saccharofermentans, and Butyrivibrio. Higher enzymes activities (cellulase and xylanase) were associated with group FC. Thus, bacterial communities in camel and sheep have a great potential to improve the utilization lignocellulosic material in animal feeding and the production of biofuel and enzymes.

Sphingobacterium faecale sp. nov., a 1-aminocyclopropane-1-carboxylate deaminase producing bacterium isolated from camel faeces.

An investigation of the diversity of 1-aminocyclopropane-1-carboxylate deaminase producing bacteria associated with camel faeces revealed the presence of a novel bacterial strain designated C459-1T. It was Gram-stain-negative, short-rod-shaped and non-motile. Strain C459-1T was observed to grow optimally at 35 °C, at pH 7.0 and in the presence of 0 % NaCl on Luria-Bertani agar medium. The cells were found to be positive for catalase and oxidase activities. The major fatty acids (>10 %) were identified as iso-C15 : 0, summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c) and iso-C17 : 0 3-OH. The predominant menaquinone was MK-7. The major polar lipids consisted of phosphatidylethanolamine, one sphingophospholipid, two unknown aminophospholipids, three unknown glycolipids and five unknown lipids. The genomic DNA G+C content was 40.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain C459-1T was affiliated with the genus Sphingobacterium and had the highest sequence similarity to Sphingobacterium tabacisoli h337T (97.0 %) and Sphingobacterium paucimobilis HER1398T (95.6 %). The average nucleotide identity and digital DNA-DNA hybridization values between strain C459-1T and S. tabacisoli h337T were 83.8 and 33.8 %, respectively. Phenotypic characteristics including enzyme activities and carbon source utilization differentiated strain C459-1T from other Sphingobacterium species. Based on its phenotypic, chemotaxonomic and phylogenetic properties, strain C459-1T represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium faecale sp. nov. is proposed, with strain is C459-1T (CGMCC 1.18716T=KCTC 82381T) as the type strain.

Investigation of extramammary sources of Group B Streptococcus reveals its unusual ecology and epidemiology in camels.

Camels are vital to food production in the drylands of the Horn of Africa, with milk as their main contribution to food security. A major constraint to camel milk production is mastitis, inflammation of the mammary gland. The condition negatively impacts milk yield and quality as well as household income. A leading cause of mastitis in dairy camels is Streptococcus agalactiae, or group B Streptococcus (GBS), which is also a commensal and pathogen of humans and cattle. It has been suggested that extramammary reservoirs for this pathogen may contribute to the occurrence of mastitis in camels. We explored the molecular epidemiology of GBS in camels using a cross-sectional study design for sample collection and phenotypic, genomic and phylogenetic analysis of isolates. Among 88 adult camels and 93 calves from six herds in Laikipia County, Kenya, GBS was detected in 20% of 50 milk samples, 25% of 152 nasal swabs, 8% of 90 oral swabs and 3% of 90 rectal swabs, but not in vaginal swabs. Per camel herd, two to four sequence types (ST) were identified using Multi Locus Sequence Typing (MLST). More than half of the isolates belonged to ST617 or its single-locus variant, ST1652, with these STs found across all sample types. Capsular serotype VI was detected in 30 of 58 isolates. In three herds, identical STs were detected in milk and swab samples, suggesting that extramammary sources of GBS may contribute to the maintenance and spread of GBS within camel herds. This needs to be considered when developing prevention and control strategies for GBS mastitis. The high nasal carriage rate, low recto-vaginal carriage rate, and high prevalence of serotype VI for GBS in camels are in stark contrast to the distribution of GBS in humans and in cattle and reveal hitherto unknown ecological and molecular features of this bacterial species.

Incidence of Brucella infection in various livestock species raised under the pastoral production system in Isiolo County, Kenya.

BACKGROUND: We implemented a longitudinal study to determine the incidence of Brucella infection in cattle, camels, sheep and goats that were being raised in a pastoral area in Isiolo County, Kenya. An initial cross-sectional survey was implemented to identify unexposed animals for follow up; that survey used 141 camels, 216 cattle, 208 sheep and 161 goats. Sera from these animals were screened for Brucella spp. using the Rose Bengal Plate test (RBPT), a modified RBPT, and an indirect multispecies Enzyme Linked Immunosorbent Assay (iELISA). Results of RBPT and iELISA were interpreted in parallel to determine seroprevalence. A total of 30 camels, 31 cattle, 22 sheep and 32 goats that were seronegative by all the above tests were recruited in a subsequent longitudinal study for follow up. These animals were followed for 12 months and tested for anti-Brucella antibodies using iELISA. Seroconversion among these animals was defined by a positive iELISA test following a negative iELISA result in the previous sampling period. All seropositive samples were further tested using real-time PCR-based assays to identify Brucella species. These analyses targeted the alkB and BMEI1162 genes for B. abortus, and B. melitensis, respectively. Data from the longitudinal study were analysed using Cox proportional hazards model that accounted for within-herds clustering of Brucella infections. RESULTS: The overall incidence rate of Brucella infection was 0.024 (95% confidence interval [CI]: 0.014-0.037) cases per animal-months at risk. Brucella infection incidence in camels, cattle, goats and sheep were 0.053 (0.022-0.104), 0.028 (0.010-0.061), 0.013 (0.003-0.036) and 0.006 (0.0002-0.034) cases per animal-month at risk, respectively. The incidence rate of Brucella infection among females and males were 0.020 (0.009-0.036) and 0.016 (0.004-0.091), respectively. Real-time PCR analyses showed that B. abortus was more prevalent than B. melitensis in the area. Results of multivariable Cox regression analysis identified species (camels and cattle) as an important predictor of Brucella spp. exposure in animals. CONCLUSIONS: This study estimated an overall brucellosis incidence of 0.024 cases per animal-months at risk with camels and cattle having higher incidence than sheep and goats. These results will inform surveillance studies in the area.

Transmission of 'Candidatus Anaplasma camelii' to mice and rabbits by camel-specific keds, Hippobosca camelina.

Anaplasmosis, caused by infection with bacteria of the genus Anaplasma, is an important veterinary and zoonotic disease. Transmission by ticks has been characterized but little is known about non-tick vectors of livestock anaplasmosis. This study investigated the presence of Anaplasma spp. in camels in northern Kenya and whether the hematophagous camel ked, Hippobosca camelina, acts as a vector. Camels (n = 976) and > 10,000 keds were sampled over a three-year study period and the presence of Anaplasma species was determined by PCR-based assays targeting the Anaplasmataceae 16S rRNA gene. Camels were infected by a single species of Anaplasma, 'Candidatus Anaplasma camelii', with infection rates ranging from 63-78% during the dry (September 2017), wet (June-July 2018), and late wet seasons (July-August 2019). 10-29% of camel keds harbored 'Ca. Anaplasma camelii' acquired from infected camels during blood feeding. We determined that Anaplasma-positive camel keds could transmit 'Ca. Anaplasma camelii' to mice and rabbits via blood-feeding. We show competence in pathogen transmission and subsequent infection in mice and rabbits by microscopic observation in blood smears and by PCR. Transmission of 'Ca. Anaplasma camelii' to mice (8-47%) and rabbits (25%) occurred readily after ked bites. Hence, we demonstrate, for the first time, the potential of H. camelina as a vector of anaplasmosis. This key finding provides the rationale for establishing ked control programmes for improvement of livestock and human health.