RESUMEN
BACKGROUND: Modified 2-tiered testing (MTTT) for Lyme disease utilizes automatable, high throughput immunoassays (AHTIs) in both tiers without involving western immunoblots, offering performance and practical advantages over standard 2-tiered testing (STTT; first-tier AHTI followed by immunoglobulin M (IgM) and immunoglobulin G (IgG) western immunoblots). For MTTT, Centers for Disease Control and Prevention recommends using AHTI test kits that have been cleared by Food and Drug Administration (FDA) specifically for this intended use. We evaluated performance of FDA-cleared MTTT commercial test kits from 3 manufacturers by comparing with STTT results. METHODS: We performed MTTT (total antibody AHTI with reflex to separate IgM and IgG AHTIs) using test kits from Diasorin, Gold Standard Diagnostics (GSD), and Zeus Scientific on 382 excess serum samples submitted to the clinical laboratory for routine Lyme disease serologic testing in July 2018, measuring agreement between MTTT and STTT using the κ statistic. RESULTS: Overall agreement with STTT was 0.87 (95% confidence interval [CI], .77-.97) using Diasorin assays (almost perfect agreement), 0.80 (95% CI, .68-.93) using GSD assays (substantial agreement) and 0.79 (95% CI, .68-.90) using Zeus assays (substantial agreement). For detection of IgM reactivity, agreement between MTTT and STTT was 0.70 (.51-.90; substantial), 0.63 (95% CI, .44-.82; substantial) and 0.56 (95% CI, .38-.73; moderate), respectively. For detection of IgG reactivity, MTTT/STTT agreement was 0.73 (95% CI,.58-.88), 0.78 (95% CI, .62-.94), and 0.75 (95% CI, .60-.90), respectively (substantial agreement in all cases). CONCLUSIONS: MTTT results obtained using commercial test kits from 3 different manufacturers had substantial to almost perfect agreement with STTT results overall and moderate to substantial agreement for IgM and IgG detection independently. Commercial MTTT tests can be used broadly for the diagnosis of Lyme disease.
Asunto(s)
Anticuerpos Antibacterianos , Inmunoglobulina G , Inmunoglobulina M , Enfermedad de Lyme , Juego de Reactivos para Diagnóstico , Pruebas Serológicas , Enfermedad de Lyme/diagnóstico , Enfermedad de Lyme/inmunología , Enfermedad de Lyme/sangre , Humanos , Pruebas Serológicas/métodos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Juego de Reactivos para Diagnóstico/normas , Anticuerpos Antibacterianos/sangre , Algoritmos , Sensibilidad y Especificidad , Inmunoensayo/métodos , Estados Unidos , Borrelia burgdorferi/inmunología , Persona de Mediana Edad , Adulto , FemeninoRESUMEN
Lyme disease is caused by the spirochete, Borrelia burgdorferi, which is transmitted by Ixodes spp ticks. The rise in Lyme disease cases since its discovery in the 1970s has reinforced the need for a vaccine. A vaccine based on B burgdorferi outer surface protein A (OspA) was approved by the Food and Drug Administration (FDA) several decades ago, but was pulled from the market a few years later, reportedly due to poor sales, despite multiple organizations concluding that it was safe and effective. Newer OspA-based vaccines are being developed and are likely to be available in the coming years. More recently, there has been a push to develop vaccines that target the tick vector instead of the pathogen to inhibit tick feeding and thus prevent transmission of tick-borne pathogens to humans and wildlife reservoirs. This review outlines the history of Lyme disease vaccines and this movement to anti-tick vaccine approaches.
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Borrelia burgdorferi , Ixodes , Vacunas contra Enfermedad de Lyme , Enfermedad de Lyme , Enfermedad de Lyme/prevención & control , Enfermedad de Lyme/inmunología , Humanos , Animales , Borrelia burgdorferi/inmunología , Vacunas contra Enfermedad de Lyme/inmunología , Ixodes/microbiología , Vacunación , Proteínas de la Membrana Bacteriana Externa/inmunología , Vacunas Bacterianas/inmunología , Vacunas Bacterianas/administración & dosificación , Antígenos de Superficie/inmunología , Lipoproteínas/inmunologíaRESUMEN
Persistent symptoms after an infection have been described for a number of infectious diseases, including Lyme disease. Studies have confirmed a moderate but consistent increase in the prevalence of such symptoms after Lyme disease, though the risk increase varies dependent on study design and the definition of persistent symptoms. Various possible predictors have been proposed, including a dysregulation of the immune system, metabolic changes, increased sensitization to pain signals, cognitive-behavioral factors, or-controversially-the persistence of the causative Borrelia bacteria or remnants thereof. Research on the precise roles of any of these factors is still ongoing. The lack of biological underpinning also makes it difficult to assess with certainty which patients' (generally nonspecific) persistent symptoms are etiologically related to the previous Lyme disease episode and which are not, particularly as these symptoms occur in the general population relatively frequently. The diagnostic criteria for posttreatment Lyme disease syndrome have shown their usefulness in both clinical and research settings but leave out a number of patients whose symptoms may fall just outside said criteria. Though the relationship between these symptoms and the previous Lyme disease episode may be very uncertain, we would argue that a uniform description and classification of these patients will aid in future research and patient management, regardless of the eventual underlying cause. Thus, we argue for an inclusive classification system for all persistent symptoms attributed to Lyme disease in order to promote validation of patient experiences and perspectives, while also maintaining scientific nuance regarding the very uncertain etiology of these patients' symptoms.
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Enfermedad de Lyme , Síndrome de la Enfermedad Post-Lyme , Humanos , Enfermedad de Lyme/diagnósticoRESUMEN
In the 40 years since Steere and colleagues first described Lyme disease, the illness has increased in incidence and distribution to become the most common vector-borne disease in the United States. Public health officials have developed, implemented, and revised surveillance systems to describe and monitor the condition. Much has been learned about the epidemiology of the illness, despite practical and logistical constraints that have encumbered the collection and interpretation of surveillance data. Future development of automated data collection from electronic health records as a source of surveillance and clinical information will address practical challenges and help answer ongoing questions about complications and persistent symptoms. Robust surveillance will be essential to monitor the effectiveness and safety of future vaccines and other preventive measures.
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Enfermedad de Lyme , Enfermedad de Lyme/epidemiología , Humanos , Estados Unidos/epidemiología , Historia del Siglo XX , Historia del Siglo XXI , Vigilancia de la Población , IncidenciaRESUMEN
BACKGROUND: Postinfectious Lyme arthritis (LA) is associated with dysregulated immunity and autoreactive T- and B-cell responses in joints. Here we explored the role of host genetic variation in this outcome. METHODS: The frequency of 253 702 single-nucleotide polymorphisms (SNPs) was determined in 147 patients with LA (87 with postinfectious LA and 60 with antibiotic-responsive LA), and for comparison in 90 patients with erythema migrans or the general population (n = 2504). Functional outcome of candidate SNPs was assessed by evaluating their impact on clinical outcome and on immune responses in blood and synovial fluid in patients with LA. RESULTS: Six SNPs associated with late cornified envelope (LCE3) genes were present at greater frequency in patients with postinfectious LA compared to those with antibiotic-responsive LA (70% vs 30%; odds ratio, 2; P < .01). These SNPs were associated with heightened levels of inflammatory Th17 cytokines in serum but lower levels of interleukin 27, a regulatory cytokine, implying that they may contribute to dysregulated Th17 immunity in blood. Moreover, in patients with postinfectious LA, the levels of these Th17 mediators correlated directly with autoantibody responses in synovial fluid, providing a possible link between LCE3 SNPs, maladaptive systemic Th17 immunity, and autoreactive responses in joints. CONCLUSIONS: Variation in the LCE3 locus, a known genetic risk factor in psoriasis and psoriatic arthritis, is associated with dysregulated systemic Th17 immunity and heightened autoantibody responses in joints. These findings underscore the importance of host genetic predisposition and systemic Th17 immunity in the pathogenesis of postinfectious (antibiotic-refractory) Lyme arthritis.
Asunto(s)
Enfermedad de Lyme , Polimorfismo de Nucleótido Simple , Células Th17 , Humanos , Enfermedad de Lyme/genética , Enfermedad de Lyme/inmunología , Células Th17/inmunología , Masculino , Femenino , Adulto , Persona de Mediana Edad , Líquido Sinovial/inmunología , Anciano , Citocinas/genética , Citocinas/metabolismo , Artritis Infecciosa/genética , Artritis Infecciosa/inmunología , Adulto JovenRESUMEN
Lyme arthritis (LA) was recognized as a separate entity in 1975 because of geographic clustering of children often diagnosed with juvenile rheumatoid arthritis in Lyme, Connecticut. After identification of erythema migrans as a common early feature of the illness, a prospective study of such patients implicated Ixodes scapularis ticks in disease transmission. In 1982, the causative agent, now called Borrelia burgdorferi, was cultured from these ticks and from Lyme disease patients. Subsequently, it was shown that LA could usually be treated successfully with oral antibiotics but sometimes required intravenous antibiotics. Yet, a small percentage of patients developed a dysregulated, proinflammatory immune response leading to persistent postinfectious synovitis with vascular damage, cytotoxic and autoimmune responses, and fibroblast proliferation, a lesion similar to that of rheumatoid arthritis. The message from postinfectious LA for other autoimmune arthritides is that a complex immune response with autoimmune features can begin with a microbial infection.
Asunto(s)
Enfermedad de Lyme , Enfermedad de Lyme/inmunología , Humanos , Animales , Historia del Siglo XX , Borrelia burgdorferi/inmunología , Historia del Siglo XXI , Antibacterianos/uso terapéutico , Ixodes/microbiologíaRESUMEN
Lyme disease is a zoonotic infection due to Ixodes tick-transmitted Borrelia burgdorferi sensu lato spirochetes and the most common vector-borne disease in the Northern Hemisphere. Despite nearly 50 years of investigation, the pathogenesis of this infection and its 2 main adverse outcomes-postinfectious Lyme arthritis and posttreatment Lyme disease syndrome-are incompletely understood. Advancement in sequencing and mass spectrometry have led to the rapid expansion of high-throughput omics technologies, including transcriptomics, metabolomics, and proteomics, which are now being applied to human diseases. This review summarizes findings of omics studies conducted on blood and tissue samples of people with acute Lyme disease and its postinfectious outcomes.
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Enfermedad de Lyme , Metabolómica , Proteómica , Humanos , Enfermedad de Lyme/microbiología , Animales , Borrelia burgdorferi/genética , Genómica , Ixodes/microbiologíaRESUMEN
BACKGROUND: During infection with the Lyme arthritis (LA) pathogen Borrelia burgdorferi, T-cell responses to both host and pathogen are dysregulated, resulting in chronic infection and frequent development of autoimmunity. METHODS: To assess CD4+ T-cell epitopes presented during development of LA, we used an unbiased, immunopeptidomics approach to characterize the major histocompatibility complex (MHC) class II immunopeptidome in B burgdorferi-infected C57BL/6 (B6) mice, which develop mild, self-limiting LA, and infected B6 Il10-/- mice, which develop severe, persistent LA at 0, 4, and 16 weeks postinfection (22-23 mice per group). RESULTS: Peptides derived from proteins involved in adaptive T- and B-cell responses and cholesterol metabolism, including human Lyme autoantigen apolipoprotein B-100 (apoB-100), were enriched in infected Il10-/- mice; whereas peptides derived from proteins involved in neutrophil extracellular net formation were enriched in infected B6 mice. Presentation of apoB-100 peptides showed evidence of epitope expansion during infection. Of several identified B burgdorferi peptides, only 1, a methyl-accepting chemotaxis protein peptide Mcp4442-462, was immunogenic. CONCLUSIONS: ApoB-100, a human Lyme autoantigen, undergoes marked epitope expansion during LA development. The paucity of immunogenic B burgdorferi epitopes supports previous findings suggesting CD4+ T-cell responses are suppressed in murine LA.
Asunto(s)
Apolipoproteína B-100 , Autoantígenos , Borrelia burgdorferi , Antígenos de Histocompatibilidad Clase II , Enfermedad de Lyme , Ratones Endogámicos C57BL , Animales , Borrelia burgdorferi/inmunología , Enfermedad de Lyme/inmunología , Enfermedad de Lyme/microbiología , Ratones , Antígenos de Histocompatibilidad Clase II/inmunología , Antígenos de Histocompatibilidad Clase II/metabolismo , Apolipoproteína B-100/inmunología , Autoantígenos/inmunología , Linfocitos T CD4-Positivos/inmunología , Epítopos de Linfocito T/inmunología , Interleucina-10/metabolismo , Ratones Noqueados , Modelos Animales de Enfermedad , Femenino , HumanosRESUMEN
The family Borreliaceae contains arthropod-borne spirochetes that cause two widespread human diseases, Lyme disease and relapsing fever. Lyme disease is a subacute, progressive illness with variable stage and tissue manifestations. Relapsing fever is an acute febrile illness with prominent bacteremia that may recur and disseminate, particularly to the nervous system. Clinical heterogeneity is a hallmark of both diseases. While human clinical manifestations are influenced by a wide variety of factors, including immune status and host genetic susceptibility, there is evidence that Borreliaceae microbial factors influence the clinical manifestations of human disease caused by this family of spirochetes. Despite these associations, the spirochete genes that influence the severity and manifestations of human disease are, for the most part, unknown. Recent work has identified lineage-specific expansions of lipoproteome-rich accessory genome elements in virulent clones of Borrelia burgdorferi. Using publicly available genome assemblies, it is shown that all Borreliaceae lineages for which sufficient sequence data are available harbor a similar pattern of strongly structured, lineage-specific expansions in their accessory genomes, particularly among lipoproteins, and that this pattern holds across phylogenetic scales including genera, species, and genotypes. The relationships among pangenome elements suggest that infrequent episodes of marked genomic change followed by clonal expansion in geographically and enzootically structured populations may account for the unique lineage structure of Borreliaceae. This analysis informs future genotype-phenotype studies among Borreliaceae and lays a foundation for studies of individual gene function guided by phylogenetic patterns of conservation, diversification, gain, and/or loss.
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Genoma Bacteriano , Filogenia , Humanos , Borrelia/genética , Borrelia/clasificación , Genómica , Enfermedad de Lyme/microbiologíaRESUMEN
Changing climates are allowing the geographic expansion of ticks and their animal hosts, increasing the risk of Borrelia-caused zoonoses in Canada. However, little is known about the genomic diversity of Borrelia from the west of the Canadian Rockies and from the tick vectors Ixodes pacificus, Ixodes auritulus and Ixodes angustus. Here, we report the whole-genome shotgun sequences of 51 Borrelia isolates from multiple tick species collected on a range of animal hosts between 1993 and 2016, located primarily in coastal British Columbia. The bacterial isolates represented three different species from the Lyme disease-causing Borrelia burgdorferi sensu lato genospecies complex [Borrelia burgdorferi sensu stricto (n=47), Borrelia americana (n=3) and Borrelia bissettiae (n=1)]. The traditional eight-gene multi-locus sequence typing (MLST) strategy was applied to facilitate comparisons across studies. This identified 13 known Borrelia sequence types (STs), established 6 new STs, and assigned 5 novel types to the nearest sequence types. B. burgdorferi s. s. isolates were further differentiated into ten ospC types, plus one novel ospC with less than 92â% nucleotide identity to all previously defined ospC types. The MLST types resampled over extended time periods belonged to previously described STs that are distributed across North America. The most geographically widespread ST, ST.12, was isolated from all three tick species. Conversely, new B. burgdorferi s. s. STs from Vancouver Island and the Vancouver region were only detected for short periods, revealing a surprising transience in space, time and host tick species, possibly due to displacement by longer-lived genotypes that expanded across North America.This article contains data hosted by Microreact.
Asunto(s)
Borrelia , Genotipo , Ixodes , Enfermedad de Lyme , Tipificación de Secuencias Multilocus , Filogenia , Secuenciación Completa del Genoma , Animales , Secuenciación Completa del Genoma/métodos , Borrelia/genética , Borrelia/clasificación , Borrelia/aislamiento & purificación , Canadá , Ixodes/microbiología , Enfermedad de Lyme/microbiología , Colombia Británica , Genoma Bacteriano , Garrapatas/microbiologíaRESUMEN
BACKGROUND: Lyme disease continues to expand in Canada and the USA and no single intervention is likely to curb the epidemic. METHODS: We propose a platform to quantitatively assess the effectiveness of a subset of Ixodes scapularis tick management approaches. The platform allows us to assess the impact of different control treatments, conducted either individually (single interventions) or in combination (combined efforts), with varying timings and durations. Interventions include three low environmental toxicity measures in differing combinations, namely reductions in white-tailed deer (Odocoileus virginianus) populations, broadcast area-application of the entomopathogenic fungus Metarhizium anisopliae, and fipronil-based rodent-targeted bait boxes. To assess the impact of these control efforts, we calibrated a process-based mathematical model to data collected from residential properties in the town of Redding, southwestern Connecticut, where an integrated tick management program to reduce I.xodes scapularis nymphs was conducted from 2013 through 2016. We estimated parameters mechanistically for each of the three treatments, simulated multiple combinations and timings of interventions, and computed the resulting percent reduction of the nymphal peak and of the area under the phenology curve. RESULTS: Simulation outputs suggest that the three-treatment combination and the bait boxes-deer reduction combination had the overall highest impacts on suppressing I. scapularis nymphs. All (single or combined) interventions were more efficacious when implemented for a higher number of years. When implemented for at least 4 years, most interventions (except the single application of the entomopathogenic fungus) were predicted to strongly reduce the nymphal peak compared with the no intervention scenario. Finally, we determined the optimal period to apply the entomopathogenic fungus in residential yards, depending on the number of applications. CONCLUSIONS: Computer simulation is a powerful tool to identify the optimal deployment of individual and combined tick management approaches, which can synergistically contribute to short-to-long-term, costeffective, and sustainable control of tick-borne diseases in integrated tick management (ITM) interventions.
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Ciervos , Ixodes , Metarhizium , Control de Ácaros y Garrapatas , Animales , Ixodes/microbiología , Ixodes/fisiología , Control de Ácaros y Garrapatas/métodos , Metarhizium/patogenicidad , Metarhizium/fisiología , Infestaciones por Garrapatas/prevención & control , Infestaciones por Garrapatas/veterinaria , Enfermedad de Lyme/prevención & control , Enfermedad de Lyme/transmisión , Connecticut , Modelos Teóricos , Pirazoles , Control Biológico de Vectores/métodos , Ninfa , Roedores , InsecticidasRESUMEN
Lyme neuroborreliosis is a rare zoonosis which can be difficult to diagnose, in particular in low endemic areas. We here report the case of a 35-year-old man presenting with disabling back pain preceded by facial monoplegia, which was wrongly treated as Bell's palsy (paralysis a frigore) and then as post-traumatic lumbosciatica. The onset of facial diplegia allowed for a definitive diagnosis. The patient was treated with ceftriaxone and symptoms gradually improved.
Asunto(s)
Antibacterianos , Parálisis de Bell , Ceftriaxona , Parálisis Facial , Neuroborreliosis de Lyme , Humanos , Masculino , Adulto , Parálisis Facial/etiología , Parálisis Facial/diagnóstico , Antibacterianos/administración & dosificación , Ceftriaxona/administración & dosificación , Neuroborreliosis de Lyme/diagnóstico , Neuroborreliosis de Lyme/complicaciones , Neuroborreliosis de Lyme/tratamiento farmacológico , Parálisis de Bell/diagnóstico , Parálisis de Bell/etiología , Dolor de Espalda/etiología , Errores Diagnósticos , Enfermedad de Lyme/diagnóstico , Enfermedad de Lyme/complicaciones , Enfermedad de Lyme/tratamiento farmacológico , Dolor de la Región Lumbar/etiologíaRESUMEN
AbstractThe incidence and geographic spread of Lyme disease are increasing, and more than 476,000 new cases a year are estimated to occur in the United States. Therefore, many clinicians in North America will need to consider how to approach a patient with a concern for Lyme disease. This Curbside Consult addresses common clinical considerations, including discussion of signs of early Lyme disease, available laboratory tests, when to treat and with which antibiotics.
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Antibacterianos , Enfermedad de Lyme , Enfermedad de Lyme/diagnóstico , Enfermedad de Lyme/tratamiento farmacológico , Humanos , Antibacterianos/uso terapéuticoRESUMEN
The interplay between the human innate immune system and bacterial cell wall components is pivotal in understanding diseases such as Crohn's disease and Lyme arthritis. Lyme disease, caused by Borrelia burgdorferi, is the most prevalent tick-borne illness in the United States, with a substantial number of cases reported annually. While antibiotic treatments are generally effective, approximately 10% of Lyme disease cases develop persistent arthritis, suggesting a dysregulated host immune response. We have previously identified a link between the immunogenic B. burgdorferi peptidoglycan (PG) and Lyme arthritis and showed that this pathogen sheds significant amounts of PG fragments during growth. Here, we synthesize these PG fragments, including ornithine-containing monosaccharides and disaccharides, to mimic the unique composition of Borrelia cell walls, using reproducible and rigorous synthetic methods. This synthetic approach allows for the modular preparation of PG derivatives, providing a diverse library of well-defined fragments. These fragments will serve as valuable tools for investigating the role of PG-mediated innate immune response in Lyme disease and aid in the development of improved diagnostic methods and treatment strategies.
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Borrelia burgdorferi , Enfermedad de Lyme , Borrelia burgdorferi/inmunología , Enfermedad de Lyme/inmunología , Enfermedad de Lyme/microbiología , Enfermedad de Lyme/tratamiento farmacológico , Humanos , Peptidoglicano/química , Peptidoglicano/inmunología , Pared Celular/químicaRESUMEN
Borrelia, spirochetes transmitted by ticks, are the etiological agents of numerous multisystemic diseases, such as Lyme borreliosis (LB) and tick-borne relapsing fever (TBRF). This study focuses on two surface proteins from two Borrelia subspecies involved in these diseases: CspZ, expressed by Borrelia burgdorferi sensu stricto (also named BbCRASP-2 for complement regulator-acquiring surface protein 2), and the factor H binding A (FhbA), expressed by Borrelia hermsii. Numerous subspecies of Borrelia, including these latter, are able to evade the immune defenses of a variety of potential vertebrate hosts in a number of ways. In this context, previous data suggested that both surface proteins play a role in the immune evasion of both Borrelia subspecies by interacting with key regulators of the alternative pathway of the human complement system, factor H (FH) and FH-like protein 1 (FHL-1). The recombinant proteins, CspZ and FhbA, were expressed in Escherichia coli and purified by one-step metal-affinity chromatography, with yields of 15 and 20 mg or pure protein for 1 L of cultured bacteria, respectively. The purity was evaluated by SDS-PAGE and HPLC and is close to about 95%. The mass of CspZ and FhbA was checked by mass spectrometry (MS). Proper folding of CspZ and FhbA was confirmed by circular dichroism (CD), and their biological activity, namely their interaction with purified FH from human serum (recombinant FH15-20 and recombinant FHL-1), was characterized by SPR. Such a study provides the basis for the biochemical characterization of the studied proteins and their biomolecular interactions which is a necessary prerequisite for the development of new approaches to improve the current diagnosis of LB and TBRF. KEY POINTS: ⢠DLS, CD, SEC-MALS, NMR, HPLC, and MS are tools for protein quality assessment ⢠Borrelia spp. possesses immune evasion mechanisms, including human host complement ⢠CspZ and FhbA interact with high affinity (pM to nM) to human FH and rFHL-1.
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Proteínas Bacterianas , Proteínas Recombinantes , Proteínas Bacterianas/genética , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/aislamiento & purificación , Humanos , Borrelia burgdorferi/genética , Borrelia burgdorferi/metabolismo , Borrelia burgdorferi/inmunología , Cromatografía de Afinidad , Escherichia coli/genética , Escherichia coli/metabolismo , Borrelia/genética , Borrelia/metabolismo , Borrelia/inmunología , Factor H de Complemento/metabolismo , Factor H de Complemento/genética , Enfermedad de Lyme/microbiología , Proteínas Inactivadoras del Complemento C3b/genética , Proteínas Inactivadoras del Complemento C3b/metabolismo , Expresión GénicaRESUMEN
Recent changes in climate and human land-use have resulted in alterations of the geographic range of many species, including human pathogens. Geographic range expansion and population growth of human pathogens increase human disease risk. Relatively little empirical work has investigated the impact of range changes on within-population variability, a contributor to both colonization success and adaptive potential, during the precise time in which populations are colonized. This is likely due to the difficulties of collecting appropriate natural samples during the dynamic phase of migration and colonization. We systematically collected blacklegged ticks (Ixodes scapularis) across New York State (NY), USA, between 2006 and 2019, a time period coinciding with a rapid range expansion of ticks and their associated pathogens including Borrelia burgdorferi, the etiological agent of Lyme disease. These samples provide a unique opportunity to investigate the population dynamics of human pathogens as they expand into novel territory. We observed that founder effects were short-lived, as gene flow from long-established populations brought almost all B. burgdorferi lineages to newly colonized populations within just a few years of colonization. By 7 years post-colonization, B. burgdorferi lineage frequency distributions were indistinguishable from long-established sites, indicating that local B. burgdorferi populations experience similar selective pressures despite geographic separation. The B. burgdorferi lineage dynamics elucidate the processes underlying the range expansion and demonstrate that migration into, and selection within, newly colonized sites operate on different time scales.
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Borrelia burgdorferi , Flujo Génico , Ixodes , Enfermedad de Lyme , Dinámica Poblacional , Borrelia burgdorferi/genética , Borrelia burgdorferi/patogenicidad , New York , Animales , Enfermedad de Lyme/microbiología , Enfermedad de Lyme/transmisión , Ixodes/microbiología , Humanos , Genética de PoblaciónRESUMEN
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.
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Coinfección , Modelos Animales de Enfermedad , Virus de la Encefalitis Transmitidos por Garrapatas , Encefalitis Transmitida por Garrapatas , Enfermedad de Lyme , Ratones Endogámicos C3H , Animales , Coinfección/microbiología , Coinfección/virología , Ratones , Virus de la Encefalitis Transmitidos por Garrapatas/fisiología , Virus de la Encefalitis Transmitidos por Garrapatas/patogenicidad , Enfermedad de Lyme/microbiología , Encefalitis Transmitida por Garrapatas/virología , Grupo Borrelia Burgdorferi , FemeninoRESUMEN
Borrelia spirochetes are the causative agents of Lyme disease and relapsing fever, two of the most common tick-borne illnesses. A characteristic feature of these spirochetes is their highly segmented genomes which consists of a linear chromosome and a mixture of up to approximately 24 linear and circular extrachromosomal plasmids. The complexity of this genomic arrangement requires multiple strategies for efficient replication and partitioning during cell division, including the generation of hairpin ends found on linear replicons mediated by the essential enzyme ResT, a telomere resolvase. Using an integrative structural biology approach employing advanced modelling, circular dichroism, X-ray crystallography and small-angle X-ray scattering, we have generated high resolution structural data on ResT from B. garinii. Our data provides the first high-resolution structures of ResT from Borrelia spirochetes and revealed active site positioning in the catalytic domain. We also demonstrate that the C-terminal domain of ResT is required for both transesterification steps of telomere resolution, and is a requirement for DNA binding, distinguishing ResT from other telomere resolvases from phage and bacteria. These results advance our understanding of the molecular function of this essential enzyme involved in genome maintenance in Borrelia pathogens.