Co-infection dynamics of B. afzelii and TBEV in C3H mice: insights and implications for future research.

Ticks are important vectors of disease, particularly in the context of One Health, where tick-borne diseases (TBDs) are increasingly prevalent worldwide. TBDs often involve co-infections, where multiple pathogens co-exist in a single host. Patients with chronic Lyme disease often have co-infections with other bacteria or parasites. This study aimed to create a co-infection model with Borrelia afzelii and tick-borne encephalitis virus (TBEV) in C3H mice and to evaluate symptoms, mortality, and pathogen level compared to single infections. Successful co-infection of C3H mice with B. afzelii and TBEV was achieved. Outcomes varied, depending on the timing of infection. When TBEV infection followed B. afzelii infection by 9 days, TBEV symptoms worsened and virus levels increased. Conversely, mice infected 21 days apart with TBEV showed milder symptoms and lower mortality. Simultaneous infection resulted in mild symptoms and no deaths. However, our model did not effectively infect ticks with TBEV, possibly due to suboptimal dosing, highlighting the challenges of replicating natural conditions. Understanding the consequences of co-infection is crucial, given the increasing prevalence of TBD. Co-infected individuals may experience exacerbated symptoms, highlighting the need for a comprehensive understanding through refined animal models. This study advances knowledge of TBD and highlights the importance of exploring co-infection dynamics in host-pathogen interactions.

Disruption of bacterial interactions and community assembly in Babesia-infected Haemaphysalis longicornis following antibiotic treatment.

BACKGROUND: A previous study highlighted the role of antibiotic-induced dysbiosis in the tick microbiota, facilitating the transstadial transmission of Babesia microti from nymph to adult in Haemaphysalis longicornis. This study builds on previous findings by analyzing sequence data from an earlier study to investigate bacterial interactions that could be linked to enhanced transstadial transmission of Babesia in ticks. The study employed antibiotic-treated (AT) and control-treated (CT) Haemaphysalis longicornis ticks to investigate shifts in microbial community assembly. Network analysis techniques were utilized to assess bacterial interactions, comparing network centrality measures between AT and CT groups, alongside studying network robustness and connectivity loss. Additionally, functional profiling was conducted to evaluate metabolic diversity in response to antibiotic treatment. RESULTS: The analysis revealed notable changes in microbial community assembly in response to antibiotic treatment. Antibiotic-treated (AT) ticks displayed a greater number of connected nodes but fewer correlations compared to control-treated (CT) ticks, indicating a less interactive yet more connected microbial community. Network centrality measures such as degree, betweenness, closeness, and eigenvector centrality, differed significantly between AT and CT groups, suggesting alterations in local network dynamics due to antibiotic intervention. Coxiella and Acinetobacter exhibited disrupted connectivity and roles, with the former showing reduced interactions in AT group and the latter displaying a loss of connected nodes, emphasizing their crucial roles in microbial network stability. Robustness tests against node removal showed decreased stability in AT networks, particularly under directed attacks, confirming a susceptibility of the microbial community to disturbances. Functional profile analysis further indicated a higher diversity and richness in metabolic capabilities in the AT group, reflecting potential shifts in microbial metabolism as a consequence of antimicrobial treatment. CONCLUSIONS: Our findings support that bacterial interaction traits boosting the transstadial transmission of Babesia could be associated with reduced colonization resistance. The disrupted microbial interactions and decreased network robustness in AT ticks suggest critical vulnerabilities that could be targeted for managing tick-borne diseases.

Microbiota-driven vaccination in soft ticks: Implications for survival, fitness and reproductive capabilities in Ornithodoros moubata.

The Ornithodoros moubata (Om) soft tick, a vector for diseases like tick-borne human relapsing fever and African swine fever, poses challenges to conventional control methods. With diminishing insecticide efficacy, harnessing the tick's microbiota through innovative approaches like microbiota-driven vaccination emerges as a promising strategy for sustainable and targeted disease control. This study investigated the intricate relationship between Pseudomonas, a keystone taxon in the Om microbiome, and its impact on tick fitness, microbiome structure and network dynamics. Utilizing in silico analyses and empirical vaccination experiments, the role of Pseudomonas within microbial networks in the tick midguts (MG) and salivary glands (SG) of Om was studied. Additionally, the consequences of anti-microbiota vaccines targeting Pseudomonas and Lactobacillus on tick fitness, microbiome diversity and community assembly were explored. The result of the study shows that in Om, Pseudomonas plays a central role in microbial networks, influencing keystone species despite being categorized as peripheral (interacting with 47 different taxa, 13 of which are keystone species). Anti-microbiota vaccination targeting Pseudomonas and Lactobacillus yields distinct effects on tick fitness, with Pseudomonas vaccination significantly impacting female tick survival, while Lactobacillus significantly reduced oviposition and fertility. Microbiome changes post-vaccination reveal diversity alterations, emphasizing the impact of vaccine choice. Community assembly dynamics and network robustness analyses highlight Pseudomonas' pivotal role, in influencing topological features and network resilience. The findings of the study provide comprehensive insights into the intricate dynamics of Om microbial networks and the potential of targeted microbiota-driven vaccines for tick control.

Rickettsial pathogens drive microbiota assembly in Hyalomma marginatum and Rhipicephalus bursa ticks.

Most tick-borne pathogens (TBPs) are secondarily acquired by ticks during feeding on infected hosts, which imposes 'priority effect' constraints, as arrival order influences the establishment of new species in a microbial community. Here we tested whether once acquired, TBPs contribute to bacterial microbiota functioning by increasing community stability. For this, we used Hyalomma marginatum and Rhipicephalus bursa ticks collected from cattle in different locations of Corsica and combined 16S rRNA amplicon sequencing and co-occurrence network analysis, with high-throughput pathogen detection, and in silico removal of nodes to test for impact of rickettsial pathogens on network properties. Despite its low centrality, Rickettsia showed preferential connections in the networks, notably with a keystone taxon in H. marginatum, suggesting facilitation of Rickettsia colonisation by the keystone taxon. In addition, conserved patterns of community assembly in both tick species were affected by Rickettsia removal, suggesting that privileged connections of Rickettsia in the networks make this taxon a driver of community assembly. However, Rickettsia removal had minor impact on the conserved 'core bacterial microbiota' of H. marginatum and R. bursa. Interestingly, networks of the two tick species with Rickettsia have similar node centrality distribution, a property that is lost after Rickettsia removal, suggesting that this taxon drives specific hierarchical interactions between bacterial microbes in the microbiota. The study indicates that tick-borne Rickettsia play a significant role in the tick bacterial microbiota, despite their low centrality. These bacteria are influential and contribute to the conservation of the 'core bacterial microbiota' while also promoting community stability.

Variation of bacterial community assembly over developmental stages and midgut of Dermanyssus gallinae.

Bacterial microbiota play an important role in the fitness of arthropods, but the bacterial microflora in the parasitic mite Dermanyssus gallinae is only partially explored; there are gaps in our understanding of the microbiota localization and in our knowledge of microbial community assembly. In this work, we have visualized, quantified the abundance, and determined the diversity of bacterial occupancy, not only across developmental stages of D. gallinae, but also in the midgut of micro-dissected female D. gallinae mites. We explored community assembly and the presence of keystone taxa, as well as predicted metabolic functions in the microbiome of the mite. The diversity of the microbiota and the complexity of co-occurrence networks decreased with the progression of the life cycle. However, several bacterial taxa were present in all samples examined, indicating a core symbiotic consortium of bacteria. The relatively higher bacterial abundance in adult females, specifically in their midguts, implicates a function linked to the biology of D. gallinae mites. If such an association proves to be important, the bacterial microflora qualifies itself as an acaricidal or vaccine target against this troublesome pest.

Tick-human interactions: from allergic klendusity to the α-Gal syndrome.

Ticks and the pathogens they transmit, including bacteria, viruses, protozoa, and helminths, constitute a growing burden for human and animal health worldwide. The ability of some animal species to acquire resistance to blood-feeding by ticks after a single or repeated infestation is known as acquired tick resistance (ATR). This resistance has been associated to tick-specific IgE response, the generation of skin-resident memory CD4+ T cells, basophil recruitment, histamine release, and epidermal hyperplasia. ATR has also been associated with protection to tick-borne tularemia through allergic klendusity, a disease-escaping ability produced by the development of hypersensitivity to an allergen. In addition to pathogen transmission, tick infestation in humans is associated with the α-Gal syndrome (AGS), a type of allergy characterized by an IgE response against the carbohydrate Galα1-3Gal (α-Gal). This glycan is present in tick salivary proteins and on the surface of tick-borne pathogens such as Borrelia burgdorferi and Anaplasma phagocytophilum, the causative agents of Lyme disease and granulocytic anaplasmosis. Most α-Gal-sensitized individuals develop IgE specific against this glycan, but only a small fraction develop the AGS. This review summarizes our current understanding of ATR and its impact on the continuum α-Gal sensitization, allergy, and the AGS. We propose that the α-Gal-specific IgE response in humans is an evolutionary adaptation associated with ATR and allergic klendusity with the trade-off of developing AGS.

Mediterranean spotted fever-like illness caused by Rickettsia sibirica mongolitimonae, North Macedonia, June 2022.

Mediterranean spotted fever-like illness (MSF-like illness) is a tick-borne disease caused by Rickettsia sibirica mongolitimonae first reported in France more than 25 years ago. Until today, more than 50 cases of MSF-like illness have been reported in different regions of Europe and Africa, highlighting variable clinical manifestation. Here we report a case of MSF-like illness following a bite from a Hyalomma tick in the Skopje region of North Macedonia.

Characterization of tick salivary gland and saliva alphagalactome reveals candidate alpha-gal syndrome disease biomarkers.

BACKGROUND: Ticks are obligate hematophagous arthropods that synthesize the glycan Galα1-3Galß1-(3)4GlcNAc-R (α-Gal) associated with the alpha-gal syndrome (AGS) or allergy to mammalian meat consumption. RESEARCH DESIGN AND METHODS: In this study, we used a proteomics approach to characterize tick proteins in salivary glands (sialome SG), secreted saliva (sialome SA) and with α-Gal modification (alphagalactome SG and SA) in model tick species associated with the AGS in the United States (Amblyomma americanum) and Australia (Ixodes holocyclus). Selected proteins reactive to sera (IgE) from patients with AGS were identified to advance in the identification of possible proteins associated with the AGS. For comparative analysis, the α-Gal content was measured in various tick species. RESULTS: The results confirmed that ticks produce proteins with α-Gal modifications and secreted into saliva during feeding. Proteins identified in tick alphagalactome SA by sera from patients with severe AGS symptomatology may constitute candidate disease biomarkers. CONCLUSIONS: The results support the presence of tick-derived proteins with α-Gal modifications in the saliva with potential implications in AGS and other disorders and protective capacity against tick infestations and pathogen infection. Future research should focus on the characterization of the function of tick glycoproteins with α-Gal in tick biology and AGS.

Freezing-Thawing Procedures Remodel the Proteome of Ram Sperm before and after In Vitro Capacitation.

Mammalian sperm must undergo a set of structural and functional changes collectively termed as capacitation to ensure a successful oocyte fertilization. However, capacitation can be compromised by cryopreservation procedures, which alter the proteome and longevity of sperm. To date, how the protein changes induced by cryopreservation could affect the acquisition of sperm fertilizing potential remains unexplored. The present study investigated the protein profile of ram sperm during in vitro capacitation before and after cryopreservation to elucidate the impact of cryopreservation on sperm capacitation at a molecular level. Fresh and cryopreserved ram sperm were incubated under capacitating (CAP) and non-capacitating (NC) conditions for 240 min. The sperm proteome of these four treatments was analyzed and compared at different incubation times using reverse phase liquid chromatography coupled to mass spectrometry (RP-LC-MS/MS). The comparison between fresh and cryopreserved sperm suggested that cryopreservation facilitated an apoptosis-stress response and redox process, while the comparison between sperm incubated in CAP and NC conditions showed that capacitation increased those biological processes associated with signaling, metabolism, motility, and reproductive processes. In addition, 14 proteins related to mitochondrial activity, sperm motility, oocyte recognition, signaling, spermatogenesis, and the apoptosis-stress response underwent significant changes in abundance over time when fresh and cryopreserved sperm incubated in CAP and NC conditions were compared. Our results indicate that disturbances in a ram sperm proteome after cryopreservation may alter the quality of sperm and its specific machinery to sustain capacitation under in vitro conditions.

Clinical gamasoidosis and antibody response in two patients infested with Ornithonyssus bursa (Acari: Gamasida: Macronyssidae).

Blood-feeding ectoparasites constitute a growing burden for human and animal health, and animal production worldwide. In particular, mites (Acari: Gamasida) of the genera Dermanyssus (Dermanyssidae) and Ornithonyssus (Macronyssidae) infest birds and cause gamasoidosis in humans. The tropical fowl mite, Ornithonyssus bursa, is commonly found in tropical and subtropical countries but rarely reported in Europe. In this research we characterized the first two cases in Spain of clinical gamasoidosis diagnosed in patients infested with O. bursa, and investigated the IgE, IgM and IgG antibody response to mite proteins and the carbohydrate Galα1-3Galß1-(3)4GlcNAc-R (α-Gal) involved in the tick-bite associated alpha-Gal syndrome (AGS). The results suggested that O. bursa is establishing across Mediterranean countries, and may increase the risk for gamasoidosis. The immune antibody response to mite proteins was higher for IgM and similar for IgE and IgG antibodies between patients and non-allergic control individuals exposed to mite or tick bites. The anti-α-Gal antibody levels were similar between patients and controls, a result supported by the absence of this carbohydrate in mites. These results suggested that mite bites do not correlate with antibody response to acarine proteins or α-Gal, and are not associated with the AGS.

Expression of Early Growth Response Gene-2 and Regulated Cytokines Correlates with Recovery from Guillain-Barré Syndrome.

Guillain-Barré syndrome (GBS) is an immune-mediated peripheral neuropathy. The goal of this research was the identification of biomarkers associated with recovery from GBS. In this study, we compared the transcriptome of PBMCs from a GBS patient and her healthy twin to discover possible correlates of disease progression and recovery. The study was then extended using GBS and spinal cord injury unrelated patients with similar medications and healthy individuals. The early growth response gene-2 (EGR2) was upregulated in GBS patients during disease recovery. The results provided evidence for the implication of EGR2 in GBS and suggested a role for EGR2 in the regulation of IL-17, IL-22, IL-28A, and TNF-ß cytokines in GBS patients. These results identified biomarkers associated with GBS recovery and suggested that EGR2 overexpression has a pivotal role in the downregulation of cytokines implicated in the pathophysiology of this acute neuropathy.

Heat-inactivated Mycobacterium bovis protects zebrafish against mycobacteriosis.

Control of mycobacterial infection constitutes a priority for human and animal health worldwide. However, effective vaccines are needed for the control of human and animal tuberculosis (TB). Adult zebrafish have become a useful model for studying the pathophysiology of mycobacterial infection and for the development of novel interventions for TB control and prevention. Recently, parenteral and oral immunization with the heat-inactivated Mycobacterium bovis vaccine (M. bovis IV) protected wild boar against TB. The objectives of this study were to provide additional support for the role of M. bovis IV in TB control using the zebrafish model and to conduct the first trial with this vaccine for the control of fish mycobacteriosis. The results showed that M. bovis IV protected zebrafish against mycobacteriosis caused by low and high infection doses of Mycobacterium marinum and provided evidence suggesting that the protective mechanism elicited by M. bovis IV in zebrafish as in other species is based on the activation of the innate immune response through the C3 pathway, with a role for the regulatory protein Akr2 in this process. These results encourage the use of M. bovis IV for TB control in different species.

Integrated Metabolomics, Transcriptomics and Proteomics Identifies Metabolic Pathways Affected by Anaplasma phagocytophilum Infection in Tick Cells.

Anaplasma phagocytophilum is an emerging zoonotic pathogen that causes human granulocytic anaplasmosis. These intracellular bacteria establish infection by affecting cell function in both the vertebrate host and the tick vector, Ixodes scapularis. Previous studies have characterized the tick transcriptome and proteome in response to A. phagocytophilum infection. However, in the postgenomic era, the integration of omics datasets through a systems biology approach allows network-based analyses to describe the complexity and functionality of biological systems such as host-pathogen interactions and the discovery of new targets for prevention and control of infectious diseases. This study reports the first systems biology integration of metabolomics, transcriptomics, and proteomics data to characterize essential metabolic pathways involved in the tick response to A. phagocytophilum infection. The ISE6 tick cells used in this study constitute a model for hemocytes involved in pathogen infection and immune response. The results showed that infection affected protein processing in endoplasmic reticulum and glucose metabolic pathways in tick cells. These results supported tick-Anaplasma co-evolution by providing new evidence of how tick cells limit pathogen infection, while the pathogen benefits from the tick cell response to establish infection. Additionally, ticks benefit from A. phagocytophilum infection by increasing survival while pathogens guarantee transmission. The results suggested that A. phagocytophilum induces protein misfolding to limit the tick cell response and facilitate infection but requires protein degradation to prevent ER stress and cell apoptosis to survive in infected cells. Additionally, A. phagocytophilum may benefit from the tick cell's ability to limit bacterial infection through PEPCK inhibition leading to decreased glucose metabolism, which also results in the inhibition of cell apoptosis that increases infection of tick cells. These results support the use of this experimental approach to systematically identify cell pathways and molecular mechanisms involved in tick-pathogen interactions. Data are available via ProteomeXchange with identifier PXD002181.

Exploring the impact of breast cancer on colonization resistance of mouse microbiota using network node manipulation.

Breast cancer, a global health concern affecting women, has been linked to alterations in the gut microbiota, impacting various aspects of human health. This study investigates the interplay between breast cancer and the gut microbiome, particularly focusing on colonization resistance-an essential feature of the microbiota's ability to prevent pathogenic overgrowth. Using a mouse model of breast cancer, we employ diversity analysis, co-occurrence network analysis, and robustness tests to elucidate the impact of breast cancer on microbiome dynamics. Our results reveal that breast cancer exposure affects the bacterial community's composition and structure, with temporal dynamics playing a role. Network analysis demonstrates that breast cancer disrupts microbial interactions and decreases network complexity, potentially compromising colonization resistance. Moreover, network robustness analysis shows the susceptibility of the microbiota to node removal, indicating potential vulnerability to pathogenic colonization. Additionally, predicted metabolic profiling of the microbiome highlights the significance of the enzyme EC 6.2.1.2 - Butyrate--CoA ligase, potentially increasing butyrate, and balancing the reduction of colonization resistance. The identification of Rubrobacter as a key contributor to this enzyme suggests its role in shaping the microbiota's response to breast cancer. This study uncovers the intricate relationship between breast cancer, the gut microbiome, and colonization resistance, providing insights into potential therapeutic strategies and diagnostic approaches for breast cancer patients.

Impact of Plasmodium relictum Infection on the Colonization Resistance of Bird Gut Microbiota: A Preliminary Study.

Avian malaria infection has been known to affect host microbiota, but the impact of Plasmodium infection on the colonization resistance in bird gut microbiota remains unexplored. This study investigated the dynamics of Plasmodium relictum infection in canaries, aiming to explore the hypothesis that microbiota modulation by P. relictum would reduce colonization resistance. Canaries were infected with P. relictum, while a control group was maintained. The results revealed the presence of P. relictum in the blood of all infected canaries. Analysis of the host microbiota showed no significant differences in alpha diversity metrics between infected and control groups. However, significant differences in beta diversity indicated alterations in the microbial taxa composition of infected birds. Differential abundance analysis identified specific taxa with varying prevalence between infected and control groups at different time points. Network analysis demonstrated a decrease in correlations and revealed that P. relictum infection compromised the bird microbiota's ability to resist the removal of taxa but did not affect network robustness with the addition of new nodes. These findings suggest that P. relictum infection reduces gut microbiota stability and has an impact on colonization resistance. Understanding these interactions is crucial for developing strategies to enhance colonization resistance and maintain host health in the face of parasitic infections.

Influence of microbiota-driven natural antibodies on dengue transmission.

Dengue has had a significant global health impact, with a dramatic increase in incidence over the past 50 years, affecting more than 100 countries. The absence of a specific treatment or widely applicable vaccine emphasizes the urgent need for innovative strategies. This perspective reevaluates current evidence supporting the concept of dual protection against the dengue virus (DENV) through natural antibodies (NAbs), particularly anti-α-Gal antibodies induced by the host's gut microbiome (GM). These anti-α-Gal antibodies serve a dual purpose. Firstly, they can directly identify DENV, as mosquito-derived viral particles have been observed to carry α-Gal, thereby providing a safeguard against human infections. Secondly, they possess the potential to impede virus development in the vector by interacting with the vector's microbiome and triggering infection-refractory states. The intricate interplay between human GM and NAbs on one side and DENV and vector microbiome on the other suggests a novel approach, using NAbs to directly target DENV and simultaneously disrupt vector microbiome to decrease pathogen transmission and vector competence, thereby blocking DENV transmission cycles.

Exploring the impact of Anaplasma phagocytophilum on colonization resistance of Ixodes scapularis microbiota using network node manipulation.

Upon ingestion from an infected host, tick-borne pathogens (TBPs) have to overcome colonization resistance, a defense mechanism by which tick microbiota prevent microbial invasions. Previous studies have shown that the pathogen Anaplasma phagocytophilum alters the microbiota composition of the nymphs of Ixodes scapularis, but its impact on tick colonization resistance remains unclear. We analyzed tick microbiome genetic data using published Illumina 16S rRNA sequences, assessing microbial diversity within ticks (alpha diversity) through species richness, evenness, and phylogenetic diversity. We compared microbial communities in ticks with and without infection with A. phagocytophilum (beta diversity) using the Bray-Curtis index. We also built co-occurrence networks and used node manipulation to study the impact of A. phagocytophilum on microbial assembly and network robustness, crucial for colonization resistance. We examined network robustness by altering its connectivity, observing changes in the largest connected component (LCC) and the average path length (APL). Our findings revealed that infection with A. phagocytophilum does not significantly alter the overall microbial diversity in ticks. Despite a decrease in the number of nodes and connections within the microbial networks of infected ticks, certain core microbes remained consistently interconnected, suggesting a functional role. The network of infected ticks showed a heightened vulnerability to node removal, with smaller LCC and longer APL, indicating reduced resilience compared to the network of uninfected ticks. Interestingly, adding nodes to the network of infected ticks led to an increase in LCC and a decrease in APL, suggesting a recovery in network robustness, a trend not observed in networks of uninfected ticks. This improvement in network robustness upon node addition hints that infection with A. phagocytophilum might lower ticks' resistance to colonization, potentially facilitating further microbial invasions. We conclude that the compromised colonization resistance observed in tick microbiota following infection with A. phagocytophilum may facilitate co-infection in natural tick populations.

Differential interactions of Rickettsia species with tick microbiota in Rh. sanguineus and Rh. turanicus.

Tick-borne rickettsioses, caused by Gram-negative bacteria of the Rickettsia genus, pose a growing global threat, with various arthropod vectors contributing to their transmission. Understanding the complex interactions within tick microbiota, including the role of Rickettsia species, is crucial for elucidating the dynamics of rickettsial diseases. Here, we investigate the taxonomic profiles and co-occurrence networks of Rickettsia in Rh. sanguineus sensus lato (s.l.) and Rh. turanicus ticks, revealing significant differences in community composition and local connectivity of Rickettsia species. While the microbiota of both tick species share common taxa, distinct differences in relative abundance and network topology suggest unique ecological niches. Moreover, robustness analysis demonstrates varying resilience to perturbations, indicating different strategies for network organization. Our findings also highlight metabolic differences between tick species, suggesting potential implications for Rickettsia interactions. Overall, this study provides insights into the intricate microbial landscape within ticks, shedding light on the functional redundancy and metabolic pathways associated with Rickettsia, thus advancing our understanding of tick-borne diseases.

Dynamic nesting of Anaplasma marginale in the microbial communities of Rhipicephalus microplus.

Interactions within the tick microbiome involving symbionts, commensals, and tick-borne pathogens (TBPs) play a pivotal role in disease ecology. This study explored temporal changes in the microbiome of Rhipicephalus microplus, an important cattle tick vector, focusing on its interaction with Anaplasma marginale. To overcome limitations inherent in sampling methods relying on questing ticks, which may not consistently reflect pathogen presence due to variations in exposure to infected hosts in nature, our study focused on ticks fed on chronically infected cattle. This approach ensures continuous pathogen exposure, providing a more comprehensive understanding of the nesting patterns of A. marginale in the R. microplus microbiome. Using next-generation sequencing, microbiome dynamics were characterized over 2 years, revealing significant shifts in diversity, composition, and abundance. Anaplasma marginale exhibited varying associations, with its increased abundance correlating with reduced microbial diversity. Co-occurrence networks demonstrated Anaplasma's evolving role, transitioning from diverse connections to keystone taxa status. An integrative approach involving in silico node removal unveils the impact of Anaplasma on network stability, highlighting its role in conferring robustness to the microbial community. This study provides insights into the intricate interplay between the tick microbiome and A. marginale, shedding light on potential avenues for controlling bovine anaplasmosis through microbiome manipulation.

Differential nested patterns of Anaplasma marginale and Coxiella-like endosymbiont across Rhipicephalus microplus ontogeny.

Understanding the intricate ecological interactions within the microbiome of arthropod vectors is crucial for elucidating disease transmission dynamics and developing effective control strategies. In this study, we investigated the ecological roles of Coxiella-like endosymbiont (CLE) and Anaplasma marginale across larval, nymphal, and adult stages of Rhipicephalus microplus. We hypothesized that CLE would show a stable, nested pattern reflecting co-evolution with the tick host, while A. marginale would exhibit a more dynamic, non-nested pattern influenced by environmental factors and host immune responses. Our findings revealed a stable, nested pattern characteristic of co-evolutionary mutualism for CLE, occurring in all developmental stages of the tick. Conversely, A. marginale exhibited variable occurrence but exerted significant influence on microbial community structure, challenging our initial hypotheses of its non-nested dynamics. Furthermore, in silico removal of both microbes from the co-occurrence networks altered network topology, underscoring their central roles in the R. microplus microbiome. Notably, competitive interactions between CLE and A. marginale were observed in nymphal network, potentially reflecting the impact of CLE on the pathogen transstadial-transmission. These findings shed light on the complex ecological dynamics within tick microbiomes and have implications for disease management strategies.