Explore the vast range of titles available.

Background Anaplasma marginale is an obligate intracellular bacterium and the main cause of bovine anaplasmosis in tropical and subtropical regions. In Egypt, data regarding the prevalence of A. marginale in ruminant hosts and of the circulating genotypes is lacking. This study therefore aimed to (i) investigate the presence, epidemiology and genotypes of A. marginale in cattle and buffaloes in Egypt, (ii) to evaluate suitable diagnostic tools and (iii) to identify co-infections of A. marginale with other selected tick-borne pathogens. Methods Blood samples were collected from 394 animals (309 cattle and 85 buffaloes) from three different areas in Egypt. For the detection of A. marginale infection, several tests were compared for their sensitivity and specificity: blood smear analysis, enzyme-linked immunosorbent assay (ELISA), PCR, real-time PCR and reverse line blot (RLB) assay. Co-infections with A. marginale, piroplasms and other Anaplasmataceae were surveyed by RLB while A. marginale genotypes were identified by amplifying and sequencing the partial msp1α gene. Results Anaplasma marginale DNA was amplified by qPCR in 68.3% of cattle and 29.4% of buffaloes. RLB showed infection with A. marginale in 50.2% of cattle and 42.5% of buffaloes. Blood smear analysis detected this agent in 16.2% of cattle and 2.4% of buffaloes. ELISA showed specific antibodies against A. marginale in 54.9% of cattle. Anaplasma marginale was associated, in cattle and buffaloes, with several tick-borne pathogens ( Theileria annulata , Babesia bovis , Babesia bigemina , Babesia occultans and Anaplasma platys ). A significant difference of A. marginale infection level was noticed in cattle, where animals between 3–5-years-old had a higher prevalence (79.2%) compared to those older than 5 years (36.4%) and younger than 3 years (59.7%) and one year (64.5%), respectively ( P  = 0.002281). Microsatellite analysis identified 15 different genotypes. Conclusions The epidemiological findings revealed high prevalence of A. marginale in cattle and buffaloes in all the investigated areas. The circulation of diverse genotypes was observed, most of these A. marginale genotypes being specific for Egypt. The qPCR assay was confirmed to be the most sensitive tool for detection of A. marginale in cattle and buffaloes even in the carrier state, highlighting the importance of using suitable diagnostic tests.

Background European bison, Bison bonasus , is a strictly protected species of large mammal, with 25% of the world’s population living in Poland. The most numerous populations of European bison live in the Białowieża Primeval Forest, northeastern Poland, and in the Bieszczady Mountains, southeastern Poland. The purpose of this study was to investigate the occurrence of Anaplasma spp. in B. bonasus from Poland. Methods Tissue samples were collected from 45 European bisons between 2021 and 2024 in the Białowieża and Bieszczady areas. Two genetic markers, 16S ribosomal DNA (rDNA) and msp4 , were used for the detection, genotyping, and phylogenetic analysis of bacteria from the genus Anaplasma . Results The prevalence of Anaplasma spp. was 40% (18/45) in the examined samples. Anaplasma phagocytophilum was detected in 10 samples, and eight samples were found to be positive for the presence of Anaplasma marginale DNA. Conclusions This study is the first report of A. marginale occurrence in Poland and the first report of A. marginale occurrence in B. bonasus in Europe. Infection by the pathogenic A. marginale in strictly protected species such as the European bison may have an impact on the health, ecology, and conservation of this endangered species. Graphical abstract

Anaplasmosis is a tick-borne disease (TBDs) caused by Anaplasma spp. In areas where TBDs are endemic, it is crucial to consider the animals’ immunological status in relation to these diseases. The true prevalence of bovine anaplasmosis, the percentage of animals with protective antibodies against this TBD, and the diagnostic characteristics of three tests (multiplex polymerase chain reaction (mPCR), competitive-inhibition enzyme-linked immunosorbent assay (cELISA), and blood smear (BS)) were estimated using a Bayesian approach. A total of 620 samples were collected in two subtropical areas of Ecuador. A significant finding of this study is that approximately 70% of cattle in those endemic areas harbored protective antibodies against Anaplasma marginale . This elevated percentage may stem from persistent exposure with a high pathogen prevalence in ticks. The decline in cELISA specificity must be attributed to cross-reactivity with protective antibodies against Anaplasma spp. It is crucial to interpret this test outcome alongside exposure history and clinical manifestations. The elevated apparent prevalence detected by cELISA and BS should be contextualized with mPCR results. The high seroprevalence and infrequent clinical outbreaks suggest that the pathogen has achieved endemic stability. This study provides valuable insights into the dynamics of anaplasmosis in endemic areas and may serve as a foundation for devising TBDs control strategies in these areas.

Despite a goat population of approximately 80 million in Pakistan during 2020−2021, the prevalence of vector-borne pathogens in goats remains largely underexplored. This study aimed to assess the molecular prevalence and phylogenetic characteristics of Anaplasma ovis, Anaplasma marginale and Anaplasma phagocytophilum in goat blood samples (N = 239) collected from three districts (Muzaffargarh, Rajanpur, and Dera Ghazi Khan) in Punjab between September 2023 and October 2024. Blood samples were first screened with generic and then with species specific primers. Molecular analyses revealed a prevalence of 39% for Anaplasma spp. and 14% for A. ovis . A. marginale and A. phagocytophilum were not detected. DNA sequencing, by targeting 16S rRNA and msp4 genes, and BLAST analysis confirmed the presence of Anaplasma spp. and A. ovis, respectively. For both screening, bacterial prevalence rates varied significantly across sampling sites (P = 0.01 for Anaplasma spp. and P = 0.04 for A. ovis ). Additionally, the prevalence of Anaplasma spp. significantly differed among goat breeds (P = 0.004), while no association was found between goat sex and bacterial infections (P > 0.05 for both screening). Notably, Anaplasma spp. infection was associated with a significant decrease in red blood cell count and hemoglobin concentration, while A. ovis infection did not affect the complete blood count profile. Phylogenetic analysis revealed that our Anaplasma spp. isolates clustered with those from Iran, Cyprus and China while our A. ovis isolates clustered with those from Pakistan, China, and Sudan. In conclusion, this study reports the presence of Anaplasma spp. and A. ovis in Pakistani goats and recommends large-scale studies across diverse geo-climatic regions to further investigate the epidemiology, genetic diversity and host-parasite interactions for effective control of these infections in local goat populations.

Ticks are of medical importance owing to their ability to transmit pathogens to humans and animals. The Rocky Mountain wood tick, Dermacentor andersoni , is a vector of a number of pathogens, including Anaplasma marginale, which is the most widespread tick-borne pathogen of livestock. Although ticks host pathogenic bacteria, they also harbor bacterial endosymbionts that have a role in tick physiology, survival, as well as pathogen acquisition and transmission. The goal of this study was to characterize the bacterial microbiome and examine the impact of microbiome disruption on pathogen susceptibility. The bacterial microbiome of two populations of D. andersoni with historically different susceptibilities to A. marginale was characterized. In this study, the microbiome was disrupted and then ticks were exposed to A. marginale or Francisella novicida to determine whether the microbiome correlated with pathogen susceptibility. Our study showed that an increase in proportion and quantity of Rickettsia bellii in the microbiome was negatively correlated to A. marginale levels in ticks. Furthermore, a decrease in Francisella endosymbionts was associated with lower F. novicida infection levels, demonstrating a positive pathogen–endosymbiont relationship. We demonstrate that endosymbionts and pathogens have varying interactions, and suggest that microbiome manipulation may provide a possible method for biocontrol by decreasing pathogen susceptibility of ticks.

Background Infections with Babesia bovis , Babesia bigemina, Theileria species and Anaplasma marginale are endemic in Kenya yet there is a lack of adequate information on their genotypes. This study established the genetic diversities of the above tick-borne hemoparasites infecting cattle in Kenya. Methods Nested PCR and sequencing were used to determine the prevalence and genetic diversity of the above parasites in 192 cattle blood samples collected from Ngong and Machakos farms. B. bovis spherical body protein 4, B. bigemina rhoptry-associated protein 1a, A. marginale major surface protein 5, Theileria spp. 18S rRNA, T. parva p104 and T. orientalis major piroplasm surface protein were used as the marker genes. Results B. bovis , B. bigemina , T. parva , T. velifera , T. taurotragi , T. mutans and A. marginale were prevalent in both farms, whereas T. ovis, Theileria sp . (buffalo) and T. orientalis were found only in Ngong farm. Co-infections were observed in more than 50 % of positive samples in both farms. Babesia parasites and A. marginale sequences were highly conserved while T. parva and T. orientalis were polymorphic. Cattle-derived T. parva was detected in Machakos farm. However, cattle and buffalo–derived Theileria were detected in Ngong farm suggesting interactions between cattle and wild buffaloes. Generally, the pathogens detected in Kenya were genetically related to the other African isolates but different from the isolates in other continents. Conclusions The current findings reaffirm the endemicity and co-infection of cattle with tick-borne hemoparasites, and the role of wildlife in pathogens transmission and population genetics in Kenya.

•Anaplasma marginale causes the economically important tick-borne disease in cattle; bovine anaplasmosis. Vaccines have had limited efficacy in preventing this global important disease.•Earlier, we produced a genetically modified A. marginale by targeted gene deletion method and the mutant exhibited in vivo growth attenuation. Immunization with it induced immunity against the wild-type A. marginale blood stabilate infection resulting from intravenous injection.•In the current study, we report that this genetically modified attenuated mutant vaccine also protects cattle against virulent A. marginale infection resulting from infected tick blood feeding. Anaplasma marginale is a tick-borne pathogen of cattle that causes bovine anaplasmosis in tropical and subtropical regions throughout the world. Killed vaccines derived from infected erythrocytes have been used for control of this disease with limited success. Recently, we described a targeted deletion mutation in the phage head-to-tail connector protein gene of A. marginale which caused bacterial attenuation in vivo and provided protection as a modified live vaccine (MLAV). Following intravenous injection of susceptible steers, the MLAV induced protective immunity against disease progression. In the current study, we demonstrated that the immunity resulting from MLAV in cattle prevents the disease progression resulting from virulent A. marginale intrastadial transmission from infected Dermacentor variabilis male ticks. The nonimmunized control steers receiving the infection from ticks developed fever, lethargy, and inappetence for several days post tick exposure with significant decreases in the packed cell volume and increases in bacteremia. In contrast, the MLAV immunized steers remained healthy after being challenged with infected ticks and this group of animals had a significant reduction in bacteremia as compared with the controls. This study demonstrated that the A. marginale MLAV provided protection against acute tick-transmitted anaplasmosis, in addition to protection documented in steers challenge-exposed with infected blood as reported previously.

Tick-borne diseases in animals are increasing rapidly worldwide, but there is insufficient information about tick-borne diseases infecting dogs in southern Egypt. Thus, in the current study, we detected the presence of Anaplasma marginale (A. marginale) and Babesia canis vogeli ( B. canis vogeli ) in the blood of dogs. The results revealed that 4/100 (4%) were positive, and a higher infection rate was found in males (75%), than females (25%). The phylogenetic analysis for the major surface protein 4 ( msp4 ) gene in this study was compared with amplicons separate from other reported isolates with alignment by identity 100% with cattle and camels from Egypt, and the phylogenetic analysis for the B. canis vogeli small subunit ribosomal RNA ( SSU rRNA ) gene in this study identified identity by 99.89% with dogs from Egypt. This report is considered the first report in southern Egypt about A. marginale in dogs based on the sequence analysis of the msp4 gene, providing new data for the classification and identification of A. marginale in dogs compared to A. marginale isolated from other animals in southern Egypt.

Anaplasma marginale is a significant tick-borne pathogen affecting ruminants; yet its prevalence and pathological impact in sheep remain underreported. This study aimed to investigate the prevalence of A. marginale in sheep from Southern Sinai, Egypt, along with its molecular characterization and the associated oxidative stress and immune responses. Microscopic examinations and PCR targeting the msp4 and msp5 genes were employed for detection, with sequencing and phylogenetic analysis performed on the msp5 gene. Oxidative stress markers, including malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH), were quantified using commercial kits. Inflammatory response was assessed via gelatin zymography for matrix metalloproteinase (MMP-2 and MMP-9). Expression levels of candidate genes, DNA methyltransferase 3 A (DNMT3a), IL-1β, and heat shock proteins (HSPs) were measured by qPCR. A high prevalence of A. marginale infection was observed, with 76% positivity by microscopy and 79.85% by PCR. Sequencing of the msp5 gene revealed 95.2–100% identity with global strains, clustering closely with the Florida (USA) strain in the phylogenetic tree. Infected sheep exhibited significantly elevated MDA levels ( p  < 0.05) and decreased SOD and GSH levels, indicating oxidative stress. MMP-2 and MMP-9 activities were also significantly increased, suggesting inflammatory involvement. Moreover, qPCR revealed significant upregulation of DNMT3a, IL-1β, and HSPs, highlighting transcriptional changes associated with infection. These findings provide valuable insights into molecular epidemiology and host response to A. marginale in sheep. The combination of msp5 sequencing, oxidative stress biomarkers, zymographic profiles, and gene expression analysis of DNMT3a, IL-1β, and HSPs suggests a potential panel of biomarkers for the diagnosis and monitoring of ovine anaplasmosis.

Background Anaplasmosis, an animal disease caused by rickettsial bacteria in the genus Anaplasma , is of considerable economic importance in livestock animals in many countries worldwide. The objectives of this study were to determine the identity, prevalence, and geographic distribution of Ehrlichia and Anaplasma in naturally infected water buffalo in Thailand using PCR amplification and sequencing of the 16S ribosomal RNA and heat shock protein groEL genes. A total of 456 buffalo blood samples from Thailand were investigated. Species identification and genetic differentiation of intra-population and inter-population with the global isolates were conducted based on nucleotide sequences. Interplay between the infection and host factors was also assessed. Results Overall, 41% of water buffalo were found to be infected with rickettsial organisms in the family Anaplasmataceae , but Ehrlichia spp. , Neorickettsia spp., and Wolbachia spp. were not found in any of the sequenced samples in this study. Female buffalo were more frequently infected with bacteria in the family Anaplasmataceae than males [71 out of 176 females (40.3%) versus 11 out of 47 males (23.4%)]. The Odds Ratio value indicated that the risk of infection for female buffalo was 2.2-fold higher than that for males ( p  < 0.05). We detected three haplotypes of A. marginale 16S rRNA gene and they were placed in a clade that was closely related to the A. marginale in buffalo in China; and cattle in Thailand, Uganda, and China. Homology searching of groEL sequences against the GenBank™ database using the BLASTn algorithm revealed that the obtained sequences had a high percentage similarity (98.36–99.62%) to A. platys sequences. The groEL sequences of three A. platys -like isolates were clustered in the same clade as the A. platys from the tick Rhipicephalus microplus in China . Conclusions Our data showed that the apparently healthy buffalo were naturally infected by bacteria in the family Anaplasmataceae at a relatively high prevalence. We also report the finding of A. platys -like infections in water buffalo in Thailand for the first time. Water buffalo serving as the reservoir host of anaplasmosis is of concern for managing the disease control and prevention in ruminants.