RESUMO
The immune deficiency (IMD) pathway directs host defense in arthropods upon bacterial infection. In Pancrustacea, peptidoglycan recognition proteins sense microbial moieties and initiate nuclear factor-κB-driven immune responses. Proteins that elicit the IMD pathway in non-insect arthropods remain elusive. Here, we show that an Ixodes scapularis homolog of croquemort (Crq), a CD36-like protein, promotes activation of the tick IMD pathway. Crq exhibits plasma membrane localization and binds the lipid agonist 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol. Crq regulates the IMD and jun N-terminal kinase signaling cascades and limits the acquisition of the Lyme disease spirochete B. burgdorferi. Additionally, nymphs silenced for crq display impaired feeding and delayed molting to adulthood due to a deficiency in ecdysteroid synthesis. Collectively, we establish a distinct mechanism for arthropod immunity outside of insects and crustaceans.
Assuntos
Artrópodes , Infecções Bacterianas , Borrelia burgdorferi , Ixodes , Doença de Lyme , Animais , Ixodes/microbiologia , Borrelia burgdorferi/genética , NF-kappa B , Doença de Lyme/microbiologiaRESUMO
Powassan virus is an emerging tick-borne virus of concern for public health, but very little is known about its transmission patterns and ecology. Here, we expanded the genomic dataset by sequencing 279 Powassan viruses isolated from Ixodes scapularis ticks from the northeastern United States. Our phylogeographic reconstructions revealed that Powassan virus lineage II was likely introduced or emerged from a relict population in the Northeast between 1940 and 1975. Sequences strongly clustered by sampling location, suggesting a highly focal geographical distribution. Our analyses further indicated that Powassan virus lineage II emerged in the northeastern United States mostly following a south-to-north pattern, with a weighted lineage dispersal velocity of ~3 km/y. Since the emergence in the Northeast, we found an overall increase in the effective population size of Powassan virus lineage II, but with growth stagnating during recent years. The cascading effect of population expansion of white-tailed deer and I. scapularis populations likely facilitated the emergence of Powassan virus in the northeastern United States.
Assuntos
Cervos , Vírus da Encefalite Transmitidos por Carrapatos , Ixodes , Animais , New EnglandRESUMO
Ticks are ectoparasites that feed on blood and have an impressive ability to consume and process enormous amounts of host blood, allowing extremely long periods of starvation between blood meals. The central role in the parasitic lifestyle of ticks is played by the midgut. This organ efficiently stores and digests ingested blood and serves as the primary interface for the transmission of tick-borne pathogens. In this study, we used a label-free quantitative approach to perform a novel dynamic proteomic analysis of the midgut of Ixodesricinus nymphs, covering their development from unfed to pre-molt stages. We identified 1534 I. ricinus-specific proteins with a relatively low proportion of host proteins. This proteome dataset, which was carefully examined by manual scrutiny, allowed precise annotation of proteins important for blood meal processing and their dynamic changes during nymphal ontogeny. We focused on midgut molecules related to lipid hydrolysis, storage, and transport, opening a yet unexplored avenue for studying lipid metabolism in ticks. Further dynamic profiling of the tick's multi-enzyme digestive network, protease inhibitors, enzymes involved in redox homeostasis and detoxification, antimicrobial peptides, and proteins responsible for midgut colonization by Borrelia spirochetes promises to uncover new targets for targeting tick nymphs, the most critical life stage for transmission the pathogens that cause tick-borne diseases.
Assuntos
Ixodes , Animais , Ixodes/parasitologia , Proteoma , Proteômica , Sistema DigestórioRESUMO
We obtained samples from the Department of Defense Serum Repository from soldiers who were stationed at Fort Liberty, North Carolina, between 1991 and 2019 to assess temporal trends in tick-borne rickettsiosis and ehrlichiosis. Serological evidence of infection was common, with nearly 1 in 5 (18.9%) demonstrating antibodies. We observed significant decreases in Rickettsia seroprevalence (adjusted odds ratio [aOR], 0.42 [95% CI, .27-.65], P = .0001) while over the same period Ehrlichia seroprevalence, albeit less common, nearly doubled (aOR, 3.61 [95% CI, 1.10-13.99], P = .048). The increase in Ehrlichia seroprevalence likely reflects increased transmission resulting from the expanding geographic range of the lone star tick.
RESUMO
Anaplasma marginale is an obligate, intracellular, tick-borne bacterial pathogen that causes bovine anaplasmosis, an often severe, production-limiting disease of cattle found worldwide. Methods to control this disease are lacking, in large part due to major knowledge gaps in our understanding of the molecular underpinnings of basic host-pathogen interactions. For example, the surface proteins that serve as adhesins and, thus, likely play a role in pathogen entry into tick cells are largely unknown. To address this knowledge gap, we developed a phage display library and screened 66 A. marginale proteins for their ability to adhere to Dermacentor andersoni tick cells. From this screen, 17 candidate adhesins were identified, including OmpA and multiple members of the Msp1 family, including Msp1b, Mlp3, and Mlp4. We then measured the transcript of ompA and all members of the msp1 gene family through time, and determined that msp1b, mlp2, and mlp4 have increased transcript during tick cell infection, suggesting a possible role in host cell binding or entry. Finally, Msp1a, Msp1b, Mlp3, and OmpA were expressed as recombinant protein. When added to cultured tick cells prior to A. marginale infection, all proteins except the C-terminus of Msp1a reduced A. marginale entry by 2.2- to 4.7-fold. Except OmpA, these adhesins lack orthologs in related pathogens of humans and animals, including Anaplasma phagocytophilum and the Ehrlichia spp., thus limiting their utility in a universal tick transmission-blocking vaccine. However, this work greatly advances efforts toward developing methods to control bovine anaplasmosis and, thus, may help improve global food security.
Assuntos
Adesinas Bacterianas , Anaplasma marginale , Dermacentor , Animais , Anaplasma marginale/genética , Adesinas Bacterianas/metabolismo , Adesinas Bacterianas/genética , Dermacentor/microbiologia , Bovinos , Aderência Bacteriana/fisiologia , Anaplasmose/microbiologia , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas da Membrana Bacteriana Externa/genética , Técnicas de Visualização da Superfície Celular , Interações Hospedeiro-Patógeno , Doenças dos Bovinos/microbiologiaRESUMO
A case of Powassan encephalitis occurred in Manitoba, Canada, after the bite of a black-legged tick. Awareness of this emerging tickborne illness is needed because the number of vector tick species is growing. No specific treatment options exist, and cases with illness and death are high. Prevention is crucial.
RESUMO
We conducted surveillance studies in Sinaloa, Mexico, to determine the circulation of tick-borne relapsing fever spirochetes. We collected argasid ticks from a home in the village of Camayeca and isolated spirochetes. Genomic analysis indicated that Borrelia turicatae infection is a threat to those living in resource-limited settings.
Assuntos
Infecções por Borrelia , Borrelia , Febre Recorrente , Carrapatos , Animais , México/epidemiologia , Borrelia/genética , Febre Recorrente/epidemiologia , Infecções por Borrelia/epidemiologiaRESUMO
Healthcare providers in North Carolina, USA, have limited experience diagnosing and managing Lyme disease because few cases occur annually statewide. We outline the prolonged diagnostic course for a patient with locally acquired Lyme disease in North Carolina. This case highlights the need for greater awareness and professional education.
Assuntos
Diagnóstico Tardio , Doença de Lyme , Humanos , North Carolina/epidemiologia , Pessoal de Saúde , Doença de Lyme/diagnóstico , Doença de Lyme/epidemiologiaRESUMO
Human-biting ticks threaten public health in the United States. Registration by the Environmental Protection Agency of products to kill host-seeking ticks or repel ticks contacting humans is indicative of their safety and effectiveness. Unregulated minimum risk products, exempt from Environmental Protection Agency registration and often based on botanical oils, are proliferating in the marketplace, but there is concern about their effectiveness to kill and repel ticks. Evaluations of such products are limited in the published literature. A review showed considerable variability among minimum risk products to kill host-seeking blacklegged ticks, with effectiveness similar to chemical pesticide products for some minimum risk products but minimal impact on the ticks for other products. Evaluations of minimum risk tick repellents have typically focused on individual active ingredients rather than formulated products, which often combine multiple active ingredients. Consumers should be aware that effectiveness to kill and repel ticks can differ among unregulated minimum risk products.
Assuntos
Repelentes de Insetos , Ixodes , Humanos , Animais , Saúde PúblicaRESUMO
Crimean-Congo hemorrhagic fever (CCHF) is a lethal viral disease that has severe public health effects throughout Africa and a case fatality rate of 10%-40%. CCHF virus was first discovered in Crimea in 1944 and has since caused a substantial disease burden in Africa. The shortage of diagnostic tools, ineffective tick control efforts, slow adoption of preventive measures, and cultural hurdles to public education are among the problems associated with continued CCHF virus transmission. Progress in preventing virus spread is also hampered by the dearth of effective serodiagnostic testing for animals and absence of precise surveillance protocols. Intergovernmental coordination, creation of regional reference laboratories, multiinstitutional public education partnerships, investments in healthcare infrastructure, vaccine development, and a One Health approach are strategic methods for solving prevention challenges. Coordinated efforts and financial commitments are needed to combat Crimean-Congo hemorrhagic fever and improve all-around readiness for newly developing infectious illnesses in Africa.
Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo , Febre Hemorrágica da Crimeia , Febre Hemorrágica da Crimeia/epidemiologia , Febre Hemorrágica da Crimeia/diagnóstico , Febre Hemorrágica da Crimeia/transmissão , Humanos , África/epidemiologia , Vírus da Febre Hemorrágica da Crimeia-Congo/isolamento & purificação , Animais , Carrapatos/virologiaRESUMO
Tick-borne encephalitis was limited to northeast portions of Italy. We report in Lombardy, a populous region in the northwest, a chamois displaying clinical signs of tickborne encephalitis virus that had multiple virus-positive ticks attached, as well as a symptomatic man. Further, we show serologic evidence of viral circulation in the area.
Assuntos
Encefalite Transmitida por Carrapatos , Encefalite Viral , Infecções por Flavivirus , Masculino , Humanos , Encefalite Transmitida por Carrapatos/epidemiologia , Itália/epidemiologiaRESUMO
We isolated severe fever with thrombocytopenia syndrome virus (SFTSV) from farmed minks in China, providing evidence of natural SFTSV infection in farmed minks. Our findings support the potential role of farmed minks in maintaining SFTSV and are helpful for the development of public health interventions to reduce human infection.
Assuntos
Surtos de Doenças , Vison , Phlebovirus , Febre Grave com Síndrome de Trombocitopenia , Phlebovirus/genética , Phlebovirus/isolamento & purificação , Phlebovirus/classificação , China/epidemiologia , Febre Grave com Síndrome de Trombocitopenia/epidemiologia , Febre Grave com Síndrome de Trombocitopenia/virologia , Animais , Vison/virologia , Filogenia , Humanos , FazendasRESUMO
We report the detection of Crimean-Congo hemorrhagic fever virus (CCHFV) in Corsica, France. We identified CCHFV African genotype I in ticks collected from cattle at 2 different sites in southeastern and central-western Corsica, indicating an established CCHFV circulation. Healthcare professionals and at-risk groups should be alerted to CCHFV circulation in Corsica.
Assuntos
Doenças dos Bovinos , Vírus da Febre Hemorrágica da Crimeia-Congo , Febre Hemorrágica da Crimeia , Filogenia , Carrapatos , Animais , Vírus da Febre Hemorrágica da Crimeia-Congo/genética , Vírus da Febre Hemorrágica da Crimeia-Congo/isolamento & purificação , Vírus da Febre Hemorrágica da Crimeia-Congo/classificação , Bovinos , França/epidemiologia , Febre Hemorrágica da Crimeia/veterinária , Febre Hemorrágica da Crimeia/epidemiologia , Febre Hemorrágica da Crimeia/virologia , Doenças dos Bovinos/virologia , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/parasitologia , Carrapatos/virologia , Genótipo , HumanosRESUMO
To estimate the determinants of spatial variation in Crimean-Congo hemorrhagic fever virus (CCHFV) transmission and to create a risk map as a preventive public health tool, we designed a survey of small domestic ruminants in Andalusia, Spain. To assess CCHFV exposure spatial distribution, we analyzed serum from 2,440 sheep and goats by using a double-antigen ELISA and modeled exposure probability with environmental predictors by using generalized linear mixed models. CCHFV antibodies detected in 84 samples confirmed low CCHFV prevalence in small domestic ruminants in the region. The best-fitted statistical model indicated that the most significant predictors of virus exposure risk were cattle/horse density and the normalized difference vegetation index. Model validation showed 99.7% specificity and 10.2% sensitivity for identifying CCHFV circulation areas. To map CCHFV exposure risk, we projected the model at a 1 × 1-km spatial resolution. Our study provides insight into CCHFV ecology that is useful for preventing virus transmission.
Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo , Febre Hemorrágica da Crimeia , Animais , Bovinos , Ovinos , Cavalos , Febre Hemorrágica da Crimeia/epidemiologia , Febre Hemorrágica da Crimeia/veterinária , Ruminantes , Espanha/epidemiologia , CabrasRESUMO
The incidence of spotted fever group (SFG) rickettsioses in the United States has tripled since 2010. Rocky Mountain spotted fever, the most severe SFG rickettsiosis, is caused by Rickettsia rickettsii. The lack of species-specific confirmatory testing obfuscates the relative contribution of R. rickettsii and other SFG Rickettsia to this increase. We report a newly recognized rickettsial pathogen, Rickettsia sp. CA6269, as the cause of severe Rocky Mountain spotted fever-like illness in 2 case-patients residing in northern California. Multilocus sequence typing supported the recognition of this pathogen as a novel Rickettsia genotype most closely related to R. rickettsii. Cross-reactivity observed for an established molecular diagnostic test indicated that Rickettsia sp. CA6269 might be misidentified as R. rickettsii. We developed a Rickettsia sp. CA6269-specific real-time PCR to help resolve this diagnostic challenge and better characterize the spectrum of clinical disease and ecologic epidemiology of this pathogen.
Assuntos
Tipagem de Sequências Multilocus , Filogenia , Rickettsia , Febre Maculosa das Montanhas Rochosas , Humanos , California/epidemiologia , Febre Maculosa das Montanhas Rochosas/diagnóstico , Febre Maculosa das Montanhas Rochosas/microbiologia , Febre Maculosa das Montanhas Rochosas/epidemiologia , Rickettsia/genética , Rickettsia/isolamento & purificação , Rickettsia/classificação , Masculino , Feminino , Pessoa de Meia-Idade , Rickettsiose do Grupo da Febre Maculosa/diagnóstico , Rickettsiose do Grupo da Febre Maculosa/microbiologia , Rickettsiose do Grupo da Febre Maculosa/epidemiologia , Adulto , Rickettsia rickettsii/genéticaRESUMO
Lyme disease surveillance based on provider and laboratory reports underestimates incidence. We developed an algorithm for automating surveillance using electronic health record data. We identified potential Lyme disease markers in electronic health record data (laboratory tests, diagnosis codes, prescriptions) from January 2017-December 2018 in 2 large practice groups in Massachusetts, USA. We calculated their sensitivities and positive predictive values (PPV), alone and in combination, relative to medical record review. Sensitivities ranged from 57% (95% CI 47%-69%) for immunoassays to 87% (95% CI 70%-100%) for diagnosis codes. PPVs ranged from 53% (95% CI 43%-61%) for diagnosis codes to 58% (95% CI 50%-66%) for immunoassays. The combination of a diagnosis code and antibiotics within 14 days or a positive Western blot had a sensitivity of 100% (95% CI 86%-100%) and PPV of 82% (95% CI 75%-89%). This algorithm could make Lyme disease surveillance more efficient and consistent.
Assuntos
Registros Eletrônicos de Saúde , Doença de Lyme , Humanos , Doença de Lyme/epidemiologia , Massachusetts/epidemiologia , Vigilância da População , Algoritmos , História do Século XXIRESUMO
Borrelia miyamotoi is an emerging tickborne pathogen that has been associated with central nervous system infections in immunocompromised patients, albeit infrequently. We describe a case-patient in Minnesota, USA, who had meningeal symptoms of 1 month duration. B. miyamotoi infection was diagnosed by Gram staining on cerebrospinal fluid and confirmed by sequencing.
Assuntos
Borrelia , Meningoencefalite , Humanos , Borrelia/isolamento & purificação , Borrelia/genética , Minnesota/epidemiologia , Meningoencefalite/microbiologia , Meningoencefalite/diagnóstico , Masculino , Infecções por Borrelia/diagnóstico , Infecções por Borrelia/microbiologia , Infecções por Borrelia/tratamento farmacológico , Infecções por Borrelia/complicações , Antibacterianos/uso terapêutico , Pessoa de Meia-Idade , Doença Aguda , FemininoRESUMO
Spotted fever rickettsiosis is rarely observed in solid organ transplant recipients, and all previously reported cases have been associated with tick bite months to years after transplantation. We describe a kidney transplant recipient in North Carolina, USA, who had a moderately severe Rickettsia parkeri infection develop during the immediate posttransplant period.
Assuntos
Transplante de Rim , Infecções por Rickettsia , Rickettsia , Humanos , Transplante de Rim/efeitos adversos , Rickettsia/genética , Rickettsia/isolamento & purificação , North Carolina , Infecções por Rickettsia/diagnóstico , Infecções por Rickettsia/microbiologia , Masculino , Transplantados , Pessoa de Meia-Idade , Antibacterianos/uso terapêutico , FemininoRESUMO
Ticks exist across diverse environments and transmit numerous pathogens. Due to their long and unique life cycles, these arthropods likely evolved robust epigenetic mechanisms that provide sustainable responses and buffers against extreme environmental conditions. Herein, we highlight how the study of the epigenetic basis of tick biology and vectorial capacity will enrich our knowledge of tick-borne infections.
Assuntos
Vetores Artrópodes/crescimento & desenvolvimento , Transmissão de Doença Infecciosa , Epigênese Genética , Interações Hospedeiro-Patógeno , Doenças Transmitidas por Carrapatos/epidemiologia , Carrapatos/fisiologia , Animais , Vetores Artrópodes/classificação , Vetores Artrópodes/genética , Humanos , Doenças Transmitidas por Carrapatos/genética , Doenças Transmitidas por Carrapatos/transmissão , Carrapatos/microbiologia , Carrapatos/parasitologia , Carrapatos/virologiaRESUMO
BACKGROUND: Ticks are blood-feeding significant arthropods that can harbour various microorganisms, including pathogens that pose health risks to humans and animals. Tick-symbiont microorganisms are believed to influence tick development, but the intricate interactions between these microbes and the relationships between different tick-borne microorganisms remain largely unexplored. RESULTS: Based on 111 tick pool samples presenting questing and engorged statuses including 752 questing tick and 1083 engorged tick from cattle and goats, which were collected in two types of geographic landscape (semi-desert and alpine meadow). We observed significant variations in the composition of tick-borne microorganisms across different environments and blood-engorgement statuses, with a pronounced divergence in symbionts compared to environmental bacteria. Metabolic predictions revealed over 90 differential pathways for tick-borne microorganisms in distinct environments and more than 80 metabolic variations in response to varying blood engorgement statuses. Interestingly, nine pathways were identified, particularly related to chorismate synthesis and carbohydrate metabolism. Moreover, microbial network relationships within tick-borne microorganism groups were highly distinct across different environments and blood-engorgement statuses. The microbial network relationships of symbionts involve some pathogenic and environmental microorganisms. Regression modelling highlighted positive correlations between the Coxiella symbiont and related pathogens, while some environmental bacteria showed strong negative correlations with Coxiella abundance. We also identified commensal bacteria/pathogens in bacterial cooccurrence patterns. Furthermore, we tested pathogenic microorganisms of each tick sample analysis revealed that 86.36% (1601/1855) of the tick samples carried one or more pathogenic microorganisms, The total carrier rate of bacterial pathogens was 43.77% ((812/1855). Most blood samples carried at least one pathogenic microorganism. The pathogens carried by the ticks have both genus and species diversity, and Rickettsia species are the most abundant pathogens among all pathogens. CONCLUSION: Our findings underscore that the bacterial pattern of ticks is dynamic and unstable, which is influenced by the environment factors and tick developmental characteristics.