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

19 páginas, 6 figuras, 5 tablasBackground: 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.UMR BIPAR is supported by the French Government’s Investissement d’Avenir program, Laboratoire d’Excellence ‘Integrative Biology of Emerging Infectious Diseases’ (grant no. ANR-10-LABX-62-IBEID). ALC-A was supported by project “CLU-2019–05-IRNASA/CSIC Unit of Excellence”, granted by the Junta de Castilla y León and co-financed by the European Union (ERDF).Peer reviewe

Incremento en la gama de hospedantes de 'Candidatus Phytoplasma sp. en Cuba

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Comparison of salivary gland and midgut microbiome in the soft ticks Ornithodoros erraticus and Ornithodoros moubata

IntroductionOrnithodoros erraticus and Ornithodoros moubata are the main vectors of African swine fever virus (ASFV) and the human relapsing fever spirochetes Borrelia hispanica and Borrelia crocidurae in the Mediterranean region and Borrelia duttoni in continental Africa. Manipulation of the tick microbiome has been shown to reduce vector fitness and competence in tick vectors, suggesting that the identification of key microbial players associated with tick tissues can inform interventions such as anti-microbiota vaccines to block pathogen development in the midgut and/or salivary glands.MethodsIn this study, we analyzed and compared the microbiome of the salivary glands and midgut of O. erraticus and O. moubata. For the taxonomic and functional characterization of the tissue-specific microbiome, we used 16S rRNA amplicon sequencing and prediction of metabolic profiles using PICRUSt2. Co-occurrence networks were built to characterize the community assembly and identify keystone taxa in each tick species.ResultsOur results revealed differences in the composition, diversity, and assembly of the bacterial microbiome of salivary glands and midgut within each tick species, but differences were more noticeable in O. moubata. Differences were also found in the microbiome of each tissue, salivary gland and midgut, between species. However, the ‘Core Association Networks (CAN)’ analysis revealed conserved patterns of interacting taxa in tissues within and between tick species. Different keystone taxa were identified in O. erraticus and O. moubata tissues, but Muribaculaceae and Alistipes were found as keystone taxa in the salivary glands of both tick species which justifies their use as anti-microbiota vaccine candidates to alter the microbiome and reduce tick fitness and/or block pathogen transmission. The high similarity of predicted metabolic pathways profiles between tissues of the two tick species suggests that taxonomic variability of the microbiome is not associated with significant changes in microbial functional profiles.ConclusionWe conclude that the taxonomic structure of the microbiome in O. erraticus and O. moubata is tissue-specific, suggesting niche partitioning of bacterial communities associated to these soft ticks. However, shared keystone taxa and conserved patterns of interacting taxa between tissues and tick species suggest the presence of key microbial players that could be used as anti-microbiota vaccine candidates to affect tick physiology and/or pathogen colonization

Prospección de potyvirus en un área suburbana de cultivo en La Habana, Cuba

The objective of this work was to determine the presence of potyviruses in associated horticultural species and weeds, in a suburban area destined to produce vegetables in Guanabacoa, Havana province. Samples of symptomatic pepper plants (Capsicum annum L.), tomato plants (Solanum lycopersicum L.), cauliflower (Brassica oleracea var. capitata L.), and green bean (Phaseolus vulgaris L. var. vulgaris), were collected in the period 2017-2019. Additionally, 30 samples of asymptomatic weeds species associated with these crops were collected: Parthenium hysterophorus L., Senna alata L, Ocimum sanctum L., Bidens alba (L.) DC., Portulaca oleracea L., Euphorbia heterophylla L., Amaranthus albus L. and Digitaria sanguinalis L. (Scop.). RNA was extracted and analyzed by RT-PCR with the use of universal primers. The presence of Potyviruses was detected in 100 % in pepper, tomato and cauliflower. Green beans samples showed 22.2 %. Four of the weeds species harvested: P. oleracea, P. hysterophorus, S. alata, and E. heterophylla, were positive to Potyviruses. These results constitute the first molecular evidence of the presence in Cuba of Potyviruses in tomato, cauliflower and French bean crops, as well as in weed species P. oleracea, P. hysterophorusL., S. alata and E. heterophylla.El objetivo de este trabajo fue determinar la presencia de potyvirus en especies hortícolas y arvenses asociadas, en un área suburbana destinada al cultivo de hortalizas en el municipio Guanabacoa, La Habana, Cuba. Entre 2017 y 2019, se recolectaron muestras de plantas sintomáticas de pimiento (Capsicum annum L.), tomate (Solanum lycopersicum L.), coliflor (Brassica oleracea var. capitata L.) y habichuela (Phaseolus vulgaris L. var. vulgaris). Adicionalmente, se recolectaron 30 muestras de especies arvenses asintomáticas, asociadas a estos cultivos de las especies Parthenium hysterophorus L., Senna alata (L.), Ocimum sanctum L., Bidens alba (L.) DC., Portulaca oleracea L., Euphorbia heterophylla L., Amaranthus albus L., Digitaria sanguinalis L. (Scop.). El ARN se extrajo y analizó por RT-PCR con el uso de cebadores universales. Se reveló la presencia de potyvirus en las muestras de pimiento (100 %), tomate (100 %), coliflor (100 %) y habichuela (22,2 %) y en cuatro de las especies de plantas arvenses recolectadas: P. oleracea, P. hysterophorus, S. alata y E. heterophylla. Estos resultados constituyen la primera evidencia molecular de la presencia, en Cuba, de potyvirus en cultivos de tomate, coliflor y habichuela; así como en las especies de arvenses: P. oleracea, P. hysterophorus, S. alata y E. heterophylla

Prospección de potyvirus en un área suburbana de cultivo en La Habana, Cuba

The objective of this work was to determine the presence of potyviruses in associated horticultural species and weeds, in a suburban area destined to produce vegetables in Guanabacoa, Havana province. Samples of symptomatic pepper plants (Capsicum annum L.), tomato plants (Solanum lycopersicum L.), cauliflower (Brassica oleracea var. capitata L.), and green bean (Phaseolus vulgaris L. var. vulgaris), were collected in the period 2017-2019. Additionally, 30 samples of asymptomatic weeds species associated with these crops were collected: Parthenium hysterophorus L., Senna alata L, Ocimum sanctum L., Bidens alba (L.) DC., Portulaca oleracea L., Euphorbia heterophylla L., Amaranthus albus L. and Digitaria sanguinalis L. (Scop.). RNA was extracted and analyzed by RT-PCR with the use of universal primers. The presence of Potyviruses was detected in 100 % in pepper, tomato and cauliflower. Green beans samples showed 22.2 %. Four of the weeds species harvested: P. oleracea, P. hysterophorus, S. alata, and E. heterophylla, were positive to Potyviruses. These results constitute the first molecular evidence of the presence in Cuba of Potyviruses in tomato, cauliflower and French bean crops, as well as in weed species P. oleracea, P. hysterophorusL., S. alata and E. heterophylla.El objetivo de este trabajo fue determinar la presencia de potyvirus en especies hortícolas y arvenses asociadas, en un área suburbana destinada al cultivo de hortalizas en el municipio Guanabacoa, La Habana, Cuba. Entre 2017 y 2019, se recolectaron muestras de plantas sintomáticas de pimiento (Capsicum annum L.), tomate (Solanum lycopersicum L.), coliflor (Brassica oleracea var. capitata L.) y habichuela (Phaseolus vulgaris L. var. vulgaris). Adicionalmente, se recolectaron 30 muestras de especies arvenses asintomáticas, asociadas a estos cultivos de las especies Parthenium hysterophorus L., Senna alata (L.), Ocimum sanctum L., Bidens alba (L.) DC., Portulaca oleracea L., Euphorbia heterophylla L., Amaranthus albus L., Digitaria sanguinalis L. (Scop.). El ARN se extrajo y analizó por RT-PCR con el uso de cebadores universales. Se reveló la presencia de potyvirus en las muestras de pimiento (100 %), tomate (100 %), coliflor (100 %) y habichuela (22,2 %) y en cuatro de las especies de plantas arvenses recolectadas: P. oleracea, P. hysterophorus, S. alata y E. heterophylla. Estos resultados constituyen la primera evidencia molecular de la presencia, en Cuba, de potyvirus en cultivos de tomate, coliflor y habichuela; así como en las especies de arvenses: P. oleracea, P. hysterophorus, S. alata y E. heterophylla

Detección de infección mixta de ‘Candidatus phytoplasma sp.’ y begomovirus afectando el cultivo de la soya en la región oriental de Cuba

The objective of the work was to detect the presence of mixed infections of phytoplasmas and begomoviruses associated with symptomatic soybean plants collected in production areas of the eastern region of Cuba. A total of 545 foliar samples of the cultivar Incasoy 27 with symptoms associated with phytoplasmas and begomoviruses were taken from 11 soybean producing localities. The samples were evaluated by nPCR to detect the presence of phytoplasmas and by RCA / RFLP to determine infection by begomoviruses. The evaluation by nPCR showed the presence of phytoplasmas in 39.45 % of the total samples collected. The analysis by RCA / RFLP showed that 47.88 % of these plants were infected by begomoviruses. The presence of mixed infections in the crop was determined in 15.96 % of the samples. Infections by both pathogens, both single and mixed, occurred in all the provinces of the country, where Holguín and Las Tunas provinces showed the highest percentages of infection. The study showed that the variability of symptoms associated with the presence of phytoplasmas and begomoviruses and mixed infections by both did not allow establishing specific relationships between symptoms and pathogens, being required the use of other diagnostic tools to confirm their specific presence. To our knowledge, this is the first report of the presence of mixed infections by begomoviruses and phytoplasmas in the soybean crop in Cuba.El objetivo del presente trabajo fue detectar la presencia de infecciones mixtas de fitoplasmas y begomovirus asociados a plantas de soya sintomáticas, colectadas en áreas de producción de la región oriental de Cuba. Se recolectaron 545 de muestras foliares del cultivar Incasoy 27, de 11 localidades productoras, con síntomas asociados a fitoplasmas y begomovirus. Las muestras se evaluaron mediante nPCR para detectar la presencia de fitoplasmas y por ACR/RFLP para determinar la infección por begomovirus. La evaluación mediante nPCR mostró la presencia de fitoplasmas en 39,45 % en el total de muestras recolectadas. El análisis por ACR/RFLP mostró que 47,88 % de estas plantas estaba infectado por begomovirus. Se determinó la presencia de infecciones mixtas en el cultivo en 15,96 % de las muestras. Las infecciones por ambos patógenos, tanto en forma simple como mixta, se presentaron en todas las provincias del país. Las provincias Holguín y Las Tunas mostraron los mayores porcentajes de infección. El estudio demostró que la variabilidad de síntomas asociados a la presencia de fitoplasmas y begomovirus e infecciones mixtas entre ambos no permitió establecer una relación específica entre síntomas y patógenos, por lo que se requiere el uso de otras herramientas de diagnóstico que permitan confirmar de forma específica la presencia de estos. A nuestro conocimiento, este resultado constituye el primer informe de la detección de infecciones mixtas de fitoplasmas y begomovirus en el cultivo de la soya en Cuba

Comparison of salivary gland and midgut microbiome in the soft ticks Ornithodoros erraticus and Ornithodoros moubata

14 páginas, 7 figuras, 4 tablasOrnithodoros erraticus and Ornithodoros moubata are the main vectors of African swine fever virus (ASFV) and the human relapsing fever spirochetes Borrelia hispanica and Borrelia crocidurae in the Mediterranean region and Borrelia duttoni in continental Africa. Manipulation of the tick microbiome has been shown to reduce vector fitness and competence in tick vectors, suggesting that the identification of key microbial players associated with tick tissues can inform interventions such as anti-microbiota vaccines to block pathogen development in the midgut and/or salivary glands.UMR BIPAR was supported by the French Government’s Investissement d’Avenir program, Laboratoire d’Excellence “Integrative Biology of Emerging Infectious Diseases” (grant no. ANR-10-LABX 62-IBEID). AW-C was supported by Programa Nacional de Becas de Postgrado en el Exterior “Don Carlos Antonio López” (grant no. 205/2018). AM was supported by the ‘Collectivité de Corse’, grant: ‘Formations superieures’ (grant code. SGCE-RAPPORT No. 0300). AC-A was supported by project “CLU-2019-05-IRNASA/CSIC Unit of Excellence,” granted by the Junta de Castilla y León and co-financed by the European Union (ERDF “Europe drives our growth”)Peer reviewe

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 ticksʼ 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

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

International audienceAbstract 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