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Infectious Disease Clinics of North... Jun 2008The spirochete Borrelia burgdorferi is a tick-borne obligate parasite whose normal reservoir is a variety of small mammals. Although infection of these natural hosts... (Review)
Review
The spirochete Borrelia burgdorferi is a tick-borne obligate parasite whose normal reservoir is a variety of small mammals. Although infection of these natural hosts does not lead to disease, infection of humans can result in Lyme disease as a consequence of the human immunopathologic response to B burgdorferi. Consistent with the pathogenesis of Lyme disease, bacterial products that allow B burgdorferi to replicate and survive seem to be primarily what is required for the bacterium to cause disease in a susceptible host. This article describes the basic biology of B burgdorferi and reviews some of the bacterial components required for infection of and survival in the mammalian and tick hosts.
Topics: Animals; Arachnid Vectors; Borrelia burgdorferi; Disease Models, Animal; Genome, Bacterial; Humans; Life Cycle Stages; Lyme Disease; Ticks
PubMed: 18452798
DOI: 10.1016/j.idc.2007.12.013 -
Virulence Dec 2023Infection with often triggers pathophysiologic perturbations that are further augmented by the inflammatory responses of the host, resulting in the severe clinical... (Review)
Review
Infection with often triggers pathophysiologic perturbations that are further augmented by the inflammatory responses of the host, resulting in the severe clinical conditions of Lyme disease. While our apprehension of the spatial and temporal integration of the virulence determinants during the enzootic cycle of is constantly being improved, there is still much to be discovered. Many of the novel virulence strategies discussed in this review are undetermined. Lyme disease spirochaetes must surmount numerous molecular and mechanical obstacles in order to establish a disseminated infection in a vertebrate host. These barriers include borrelial relocation from the midgut of the feeding tick to its body cavity and further to the salivary glands, deposition to the skin, haematogenous dissemination, extravasation from blood circulation system, evasion of the host immune responses, localization to protective niches, and establishment of local as well as distal infection in multiple tissues and organs. Here, the various well-defined but also possible novel strategies and virulence mechanisms used by to evade obstacles laid out by the tick vector and usually the mammalian host during colonization and infection are reviewed.
Topics: Animals; Humans; Borrelia burgdorferi; Virulence; Lyme Disease; Virulence Factors; Mammals
PubMed: 37814488
DOI: 10.1080/21505594.2023.2265015 -
Microbiology Spectrum Jun 2015Borrelia burgdorferi, the spirochetal agent of Lyme disease, is a zoonotic pathogen that is maintained in a natural cycle that typically involves mammalian reservoir...
Borrelia burgdorferi, the spirochetal agent of Lyme disease, is a zoonotic pathogen that is maintained in a natural cycle that typically involves mammalian reservoir hosts and a tick vector of the Ixodes species. During each stage of the enzootic cycle, B. burgdorferi is exposed to environments that differ in temperature, pH, small molecules, and most important, nutrient sources. B. burgdorferi has a highly restricted metabolic capacity because it does not contain a tricarboxylic acid cycle, oxidative phosphorylation, or any pathways for de novo biosynthesis of carbohydrates, amino acids, or lipids. Thus, B. burgdorferi relies solely on glycolysis for ATP production and is completely dependent on the transport of nutrients and cofactors from extracellular sources. Herein, pathways for carbohydrate uptake and utilization in B. burgdorferi are described. Regulation of these pathways during the different phases of the enzootic cycle is discussed. In addition, a model for differential control of nutrient flux through the glycolytic pathway as the spirochete transits through the enzootic cycle is presented.
Topics: Animals; Borrelia burgdorferi; Carbon; Disaccharides; Gene Expression Regulation, Bacterial; Glycolysis; Humans; Ixodes; Lyme Disease; Mammals; Zoonoses
PubMed: 26185064
DOI: 10.1128/microbiolspec.MBP-0011-2014 -
PloS One 2022Borrelia burgdorferi and Borrelia miyamotoi are tick-vectored zoonotic pathogens maintained in wildlife species. Tick populations are establishing in new areas globally...
Borrelia burgdorferi and Borrelia miyamotoi are tick-vectored zoonotic pathogens maintained in wildlife species. Tick populations are establishing in new areas globally in response to climate change and other factors. New Brunswick is a Canadian maritime province at the advancing front of tick population establishment and has seen increasing numbers of ticks carrying B. burgdorferi, and more recently B. miyamotoi. Further, it is part of a region of Atlantic Canada with wildlife species composition differing from much of continental North America and little information exists as to the presence and frequency of infection of Borrelia spp. in wildlife in this region. We used a citizen science approach to collect a wide range of animals including migratory birds, medium-sized mammals, and small mammals. In total we tested 339 animals representing 20 species for the presence of B. burgdorferi and B. miyamotoi. We have developed new nested PCR primers and a protocol with excellent specificity for detecting both of these Borrelia species, both single and double infections, in tissues and organs of various wildlife species. The positive animals were primarily small non-migratory mammals, approximately twice as many were infected with B. burgdorferi than B. miyamotoi and one animal was found infected with both. In addition to established reservoir species, the jumping mouse (Napaeozapus insignis) was found frequently infected; this species had the highest infection prevalence for both B. burgdorferi and B. miyamotoi and has not previously been identified as an important carrier for either Borrelia species. Comprehensive testing of tissues found that all instances of B. burgdorferi infection were limited to one tissue within the host, whereas two of the five B. miyamotoi infections were diffuse and found in multiple systems. In the one coinfected specimen, two fetuses were also recovered and found infected with B. miyamotoi. This presumptive transplacental transmission suggests that vertical transmission in mammals is possible. This finding implies that B. miyamotoi could rapidly spread into wildlife populations, as well as having potential human health implications.
Topics: Animals; Animals, Wild; Birds; Borrelia; Borrelia burgdorferi; Canada; DNA, Bacterial; Disease Vectors; Fetus; Lyme Disease; Mice; Phylogeny; Polymerase Chain Reaction
PubMed: 35061805
DOI: 10.1371/journal.pone.0262229 -
Cellular Microbiology Feb 2019Borrelia burgdorferi is the causative agent of Lyme disease that persists in a complex enzootic life cycle, involving Ixodes ticks and vertebrate hosts. The microbe... (Review)
Review
Borrelia burgdorferi is the causative agent of Lyme disease that persists in a complex enzootic life cycle, involving Ixodes ticks and vertebrate hosts. The microbe invades ticks and vertebrate hosts in spite of active immune surveillance and potent microbicidal responses, and establishes long-term infection utilising mechanisms that are yet to be unravelled. The pathogen can cause multi-system disorders when transmitted to susceptible mammalian hosts, including in humans. In the past decades, several studies identified a limited number of B. burgdorferi gene-products critical for pathogen persistence, transmission between the vectors and the host, and host-pathogen interactions. This review will focus on the interactions between B. burgdorferi proteins, as well as between microbial proteins and host components, protein and non-protein components, highlighting their roles in pathogen persistence in the mammalian host. A better understanding of the contributions of protein interactions in the microbial virulence and persistence of B. burgdorferi would support development of novel therapeutics against the infection.
Topics: Animals; Bacterial Proteins; Borrelia burgdorferi; Host-Pathogen Interactions; Humans; Ixodes; Lyme Disease; Protein Binding; Protein Interaction Maps; Virulence; Virulence Factors
PubMed: 29934966
DOI: 10.1111/cmi.12885 -
Microbiology and Molecular Biology... May 2021The spp. are tick-borne pathogenic spirochetes that include the agents of Lyme disease and relapsing fever. As part of their life cycle, the spirochetes traffic between... (Review)
Review
The spp. are tick-borne pathogenic spirochetes that include the agents of Lyme disease and relapsing fever. As part of their life cycle, the spirochetes traffic between the tick vector and the vertebrate host, which requires significant physiological changes and remodeling of their outer membranes and proteome. This crucial proteome resculpting is carried out by a diverse set of proteases, adaptor proteins, and related chaperones. Despite its small genome, has dedicated a large percentage of its genome to proteolysis, including a full complement of ATP-dependent proteases. Energy-driven proteolysis appears to be an important physiological feature of this dual-life-cycle bacterium. The proteolytic arsenal of is strategically deployed for disposal of proteins no longer required as they move from one stage to another or are transferred from one host to another. Likewise, the spp. are systemic organisms that need to break down and move through host tissues and barriers, and so their unique proteolytic resources, both endogenous and borrowed, make movement more feasible. Both the Lyme disease and relapsing fever spp. bind plasminogen as well as numerous components of the mammalian plasminogen-activating system. This recruitment capacity endows the spirochetes with a borrowed proteolytic competency that can lead to increased invasiveness.
Topics: Animals; Bacterial Proteins; Borrelia burgdorferi; Humans; Lyme Disease; Plasminogen; Proteolysis; Relapsing Fever
PubMed: 33980587
DOI: 10.1128/MMBR.00217-20 -
Frontiers in Cellular and Infection... 2014Lyme disease is a long-term infection whose most severe pathology is characterized by inflammatory arthritis of the lower bearing joints, carditis, and neuropathy. The... (Review)
Review
Lyme disease is a long-term infection whose most severe pathology is characterized by inflammatory arthritis of the lower bearing joints, carditis, and neuropathy. The inflammatory cascades are initiated through the early recognition of invading Borrelia burgdorferi spirochetes by cells of the innate immune response, such as neutrophils and macrophage. B. burgdorferi does not have an intracellular niche and thus much research has focused on immune pathways activated by pathogen recognition molecules at the cell surface, such as the Toll-like receptors (TLRs). However, in recent years, studies have shown that internalization of the bacterium by host cells is an important component of the defense machinery in response to B. burgdorferi. Upon internalization, B. burgdorferi is trafficked through an endo/lysosomal pathway resulting in the activation of a number of intracellular pathogen recognition receptors including TLRs and Nod-like receptors (NLRs). Here we will review the innate immune molecules that participate in both cell surface and intracellular immune activation by B. burgdorferi.
Topics: Animals; Borrelia burgdorferi; Host-Pathogen Interactions; Humans; Immunity, Innate; Lyme Disease
PubMed: 25566512
DOI: 10.3389/fcimb.2014.00175 -
FEBS Letters Aug 2020Borreliosis (Lyme disease) is a spirochetal disease caused by the species complex of Borrelia burgdorferi transmitted by Ixodes spp. ticks. Recorded to be the most... (Review)
Review
Borreliosis (Lyme disease) is a spirochetal disease caused by the species complex of Borrelia burgdorferi transmitted by Ixodes spp. ticks. Recorded to be the most common tick-borne disease in the world, the last two decades have seen an increase in disease incidence and distribution, exceeding 360 000 cases in Europe alone. If untreated, infection may cause skin symptoms, arthritis, and neurological or cardiac complications. Borrelia spirochetes have developed strategies to evade the mammalian host immune system. These include the complement system, which is an important first-line defense mechanism against invading microbes. To evade the complement, spirochetes bind soluble complement regulators factor H (FH), factor H-like protein, and C4bp to their outer surfaces. B. burgdorferi spirochetes can inhibit the classical pathway of complement by the outer surface protein (Osp) BBK32, which blocks the activation of the C1 complex, composed of C1q, C1r, and C1s. The FH-binding proteins of borreliae include Osps OspE, CspA, and CspZ. Following repeated infections, antibodies against these proteins develop and may provide functional immunity against borreliosis. This review discusses critical immune evasion strategies, focusing on complement evasion by borreliae.
Topics: Animals; Antibodies, Bacterial; Bacterial Proteins; Borrelia burgdorferi; Complement System Proteins; Humans; Immune Evasion; Lyme Disease
PubMed: 32748966
DOI: 10.1002/1873-3468.13894 -
Infection Feb 2011
Topics: Bacteremia; Borrelia burgdorferi; Humans; Lyme Disease
PubMed: 21311945
DOI: 10.1007/s15010-011-0089-5 -
Journal of the American Veterinary... Nov 2003Despite more than 25 years' experience with Lyme borreliosis, much remains to be learned about this complex zoonosis. Practicing veterinarians, particularly those in the... (Review)
Review
Despite more than 25 years' experience with Lyme borreliosis, much remains to be learned about this complex zoonosis. Practicing veterinarians, particularly those in the northeastern and upper midwestern states, where Lyme borreliosis is highly endemic, should be familiar with the ecologic features and typical clinical signs of Lyme borreliosis. Interpretation of signs and serologic test results should be made with consideration of the regional prevalence of Lyme borreliosis and the animal's opportunity for exposure to infected Ixodes spp. The availability of recently marketed topical acaracides is a valuable adjunctive measure in prevention of Lyme borreliosis. A maximally effective prevention strategy should include consideration of environmental modification, activity restrictions, routine examinations for ticks, prompt removal of attached ticks, and vaccination. Technologic advances, such as the C6 EIA and the Osp A recombinant vaccine, offer the promise of additional tools for the clinical management and prevention of this tick-borne zoonosis.
Topics: Animals; Animals, Domestic; Borrelia burgdorferi; Dogs; Horses; Humans; Ixodes; Lyme Disease; Public Health; Tick Control; United States; Zoonoses
PubMed: 14621212
DOI: 10.2460/javma.2003.223.1261