Browse
Submit Data
Databases
API
Help

Dataset Information

20 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Relapsing fever spirochetes retain infectivity after prolonged in vitro cultivation.

ABSTRACT: Borrelia hermsii and Borrelia burgdorferi, two closely related spirochetes, are the etiological agents of tick-borne relapsing fever and Lyme disease, respectively. Previous studies have shown the loss of infectivity of B. burgdorferi is associated with in vitro cultivation. This diminished infectivity of B. burgdorferi has occurred as early as three in vitro passages, and the loss of plasmids have been observed with these less virulent to noninfective cultures. The effects of long-term in vitro cultivation on B. hermsii have not been investigated. However, understanding the degree of genomic degradation during in vitro cultivation is important for investigating pathogenic mechanisms of spirochetes. In this study, we analyzed the effects of continuous in vitro cultivation on the genomic composition and infectivity of B. hermsii and B. turicatae.We report that all seven isolates of B. hermsii and the one isolate of B. turicatae examined retained infectivity in mice after 1 year of continuous in vitro cultivation. Furthermore, there were few apparent differences in the plasmid profiles after long-term cultivation. Two isolates of B. hermsii remained infective after high passage despite losing a portion of the 200-kb linear plasmid containing the fhbA gene encoding the factor H binding protein. Also, sequence analysis of multiple B. hermsii isolates demonstrated two types of fhbA with complete congruence with the two genomic groups of B. hermsii spirochetes. Therefore, these results suggest that relapsing fever spirochetes are genetically stable during in vitro cultivation, and the fhbA-containing segment of DNA that is lost during cultivation is not required for infection.

SUBMITTER: Lopez JE

PROVIDER: S-EPMC2605162 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Typing African relapsing fever spirochetes.

Project description:Relapsing fever Borrelia spp. challenge microbiologic typing because they possess segmented genomes that maintain essential genes on large linear plasmids. Antigenic variation further complicates typing. Intergenic spacer (IGS, between 16S-23S genes) heterogeneity provides resolution among Lyme disease-associated and some relapsing fever spirochetes. We used an IGS fragment for typing East African relapsing fever Borrelia spp. Borrelia recurrentis and their louse vectors showed 2 sequence types, while 4 B. duttonii and their tick vectors had 4 types. IGS typing was unable to discriminate between the tick- and louseborne forms of disease. B. crocidurae, also present in Africa, was clearly resolved from the B. recurrentis/B. duttonii complex. IGS analysis of ticks showed relapsing fever Borrelia spp. and a unique clade, distant from those associated with relapsing fever, possibly equivalent to a novel species in ticks from this region. Clinical significance of this spirochete is undetermined.

| S-EPMC3367362 | biostudies-literature

Immune Evasion Strategies of Relapsing Fever Spirochetes.

Project description:Relapsing fever (RF) is claimed a neglected arthropod-borne disease caused by a number of diverse human pathogenic Borrelia (B.) species. These RF borreliae are separated into the groups of tick-transmitted species including B. duttonii, B. hermsii, B. parkeri, B. turicatae, B. hispanica, B. persica, B. caucasica, and B. myiamotoi, and the louse-borne Borrelia species B. recurrentis. As typical blood-borne pathogens achieving high cell concentrations in human blood, RF borreliae (RFB) must outwit innate immunity, in particular complement as the first line of defense. One prominent strategy developed by RFB to evade innate immunity involves inactivation of complement by recruiting distinct complement regulatory proteins, e.g., C1 esterase inhibitor (C1-INH), C4b-binding protein (C4BP), factor H (FH), FH-like protein-1 (FHL-1), and factor H-related proteins FHR-1 and FHR-2, or binding of individual complement components and plasminogen, respectively. A number of multi-functional, complement and plasminogen-binding molecules from distinct Borrelia species have previously been identified and characterized, exhibiting considerable heterogeneity in their sequences, structures, gene localization, and their capacity to bind host-derived proteins. In addition, RFB possess a unique system of antigenic variation, allowing them to change the composition of surface-exposed variable major proteins, thus evading the acquired immune response of the human host. This review focuses on the current knowledge of the immune evasion strategies by RFB and highlights the role of complement-interfering and infection-associated molecules for the pathogenesis of RFB.

| S-EPMC7390862 | biostudies-literature

A novel surface antigen of relapsing fever spirochetes can discriminate between relapsing fever and Lyme borreliosis.

Project description:In a previous immunoproteome analysis of Borrelia hermsii, candidate antigens that bound IgM antibodies from mice and patients infected with relapsing fever spirochetes were identified. One candidate that was identified is a hypothetical protein with a molecular mass of 57 kDa that we have designated Borrelia immunogenic protein A (BipA). This protein was further investigated as a potential diagnostic antigen for B. hermsii given that it is absent from the Borrelia burgdorferi genome. The bipA locus was amplified and sequenced from 39 isolates of B. hermsii that had been acquired from western North America. bipA was also expressed as a recombinant fusion protein. Serum samples from mice and patients infected with B. hermsii or B. burgdorferi were used to confirm the immunogenicity of the recombinant protein in patients infected with relapsing fever spirochetes. Lastly, in silico and experimental analysis indicated that BipA is a surface-exposed lipoprotein in B. hermsii. These findings enhance the capabilities of diagnosing infection with relapsing fever spirochetes.

| S-EPMC2849321 | biostudies-literature

Cotransmission of divergent relapsing fever spirochetes by artificially infected Ornithodoros hermsi.

Project description:The soft tick Ornithodoros hermsi, which ranges in specific arboreal zones of western North America, acts as a vector for the relapsing fever spirochete Borrelia hermsii. Two genomic groups (genomic group I [GGI] and GGII) of B. hermsii are differentiated by multilocus sequence typing yet are codistributed in much of the vector's range. To test whether the tick vector can be infected via immersion, noninfected, colony-derived O. hermsi larvae were exposed to reduced-humidity conditions before immersion in culture suspensions of several GGI and GGII isolates. We tested for spirochetes in ticks by immunofluorescence microscopy and in mouse blood by quantitative PCR of the vtp locus to differentiate spirochete genotypes. The immersed larval ticks were capable of spirochete transmission to mice at the first nymphal feeding. Tick infection with mixed cultures of isolates DAH (vtp-6) (GGI) and MTW-2 (vtp-5) (GGII) resulted in ticks that caused spirochetemias in mice consisting of MTW-2 or both DAH and MTW-2. These findings show that this soft tick species can acquire B. hermsii by immersion in spirochete suspensions, that GGI and GGII isolates can coinfect the tick vector by this method, and that these spirochetes can be cotransmitted to a rodent host.

| S-EPMC3233084 | biostudies-literature

Relapsing fever spirochetes contain chromosomal genes with unique direct tandemly repeated sequences.

Project description:Genome sequencing of the relapsing fever spirochetes Borrelia hermsii and Borrelia turicatae identified three open reading frames (ORFs) on the chromosomes that contained internal, tandemly repeated amino acid sequences that were absent in the Lyme disease spirochete Borrelia burgdorferi. The predicted amino acid sequences of these genes (BH0209, BH0512, and BH0553) have hydrophobic N termini, indicating that these proteins may be secreted. B. hermsii transcribed the three ORFs in vitro, and the BH0512- and BH0553-encoded proteins (PBH-512 and PBH-553) were produced in vitro and in experimentally infected mice. PBH-512 and PBH-553 were on the spirochete's outer surface, and antiserum to these proteins reduced the adherence of B. hermsii to red blood cells. PCR analyses of 28 isolates of B. hermsii and 8 isolates of B. turicatae demonstrated polymorphism in each gene correlated with the number of repeats. Serum samples from relapsing fever patients reacted with recombinant PBH-512 and PBH-553, suggesting that these proteins are produced during human infection. These polymorphic proteins may be involved in the pathogenicity of these relapsing fever spirochetes and provide a mechanism for antigenic heterogeneity within their populations.

| S-EPMC1087331 | biostudies-literature

Relapsing fever-like spirochetes infecting European vector tick of Lyme disease agent.

Project description:To determine whether relapsing fever-like spirochetes associated with hard ticks may infect Ixodes ricinus ticks in central Europe, we screened questing ticks for 16S rDNA similar to that of Asian and American relapsing fever-like spirochetes. We compared the prevalence of these spirochetes to that of Lyme disease spirochetes transmitted by the same vector. Relapsing fever-like spirochetes infect 3.5% of questing vector ticks in our three central European sites near the Rhein Valley. These spirochetes differ genetically from their American and Asian analogs while being relatively homogeneous in the region we sampled. The Lyme disease genospecies most commonly detected in central Europe are distributed broadly, whereas those that are less frequently found appear to be place-specific. The absence of co-infected ticks suggests that relapsing fever-like and Lyme disease spirochetes may not share hosts. Exposure risk for relapsing fever-like spirochetes is similar to that of certain Lyme disease genospecies. Although many persons may be bitten by ticks infected by relapsing fever-like spirochetes, health implications remain unknown.

| S-EPMC3000135 | biostudies-literature

"Conformational dynamics of C1r inhibitor proteins from Lyme disease and relapsing fever spirochetes".

Project description:Borrelial pathogens are vector-borne etiological agents of Lyme disease, relapsing fever, and Borrelia miyamotoi disease. These spirochetes each encode several surface-localized lipoproteins that bind to components of the human complement system. BBK32 is an example of a borrelial lipoprotein that protects the Lyme disease spirochete from complement-mediated attack. The complement inhibitory activity of BBK32 arises from an alpha helical C-terminal domain that interacts directly with the initiating protease of the classical pathway, C1r. Borrelia miyamotoi spirochetes encode BBK32 orthologs termed FbpA and FbpB, and these proteins also inhibit C1r, albeit via distinct recognition mechanisms. The C1r-inhibitory activities of a third ortholog termed FbpC, which is found exclusively in relapsing fever spirochetes, remains unknown. Here we report the crystal structure of the C-terminal domain of B. hermsii FbpC to a limiting resolution of 1.5 Å. Surface plasmon resonance studies and assays of complement function demonstrate that FbpC retains potent BBK32-like anti-complement activities. Based on the structure of FbpC, we hypothesized that conformational dynamics of the complement inhibitory domains of borrelial C1r inhibitors may differ. To test this, we utilized the crystal structures of the C-terminal domains of BBK32, FbpA, FbpB, and FbpC to carry out 1 µs molecular dynamics simulations, which revealed borrelial C1r inhibitors adopt energetically favored open and closed states defined by two functionally critical regions. This study advances our understanding of how protein dynamics contribute to the function of bacterial immune evasion proteins and reveals a surprising plasticity in the structures of borrelial C1r inhibitors.

| S-EPMC10002728 | biostudies-literature

Colony formation in solid medium by the relapsing fever spirochetes Borrelia hermsii and Borrelia turicatae.

Project description:Relapsing fever (RF) in North America is caused primarily by the spirochete Borrelia hermsii and is associated with the bite of its tick vector Ornithodoros hermsi. Although this spirochete was known long before the discovery of the Lyme disease (LD) spirochete, Borrelia burgdorferi, basic methods to facilitate the study of B. hermsii have lagged behind. One important technique to expedite the study of the molecular biology and pathogenesis of B. hermsii would be a reliable method to grow and clone these bacteria in solid medium, which we now describe. We have defined the solidifying agent, plating temperature, oxygen concentration, and pH for the efficient plating of two species of RF spirochetes, B. hermsii and Borrelia turicatae. Importantly, this technique allowed us to successfully isolate virulent, clonal cell lines of spirochetes, and to enumerate and isolate viable B. hermsii from infected mouse blood and tick tissues. Our results also demonstrate the value of testing a range of several environmental variables to increase the efficiency of bacterial isolation, which may be helpful for researchers working on other prokaryotes that are intractable for in vitro growth.

| S-EPMC5803322 | biostudies-literature

Conformational dynamics of complement protease C1r inhibitor proteins from Lyme disease- and relapsing fever-causing spirochetes.

Project description:Borrelial pathogens are vector-borne etiological agents known to cause Lyme disease, relapsing fever, and Borrelia miyamotoi disease. These spirochetes each encode several surface-localized lipoproteins that bind components of the human complement system to evade host immunity. One borrelial lipoprotein, BBK32, protects the Lyme disease spirochete from complement-mediated attack via an alpha helical C-terminal domain that interacts directly with the initiating protease of the classical complement pathway, C1r. In addition, the B. miyamotoi BBK32 orthologs FbpA and FbpB also inhibit C1r, albeit via distinct recognition mechanisms. The C1r-inhibitory activities of a third ortholog termed FbpC, which is found exclusively in relapsing fever-causing spirochetes, remains unknown. Here, we report the crystal structure of the C-terminal domain of Borrelia hermsii FbpC to a limiting resolution of 1.5 Å. We used surface plasmon resonance and assays of complement function to demonstrate that FbpC retains potent BBK32-like anticomplement activities. Based on the structure of FbpC, we hypothesized that conformational dynamics of the complement inhibitory domains of borrelial C1r inhibitors may differ. To test this, we utilized the crystal structures of the C-terminal domains of BBK32, FbpA, FbpB, and FbpC to carry out molecular dynamics simulations, which revealed borrelial C1r inhibitors adopt energetically favored open and closed states defined by two functionally critical regions. Taken together, these results advance our understanding of how protein dynamics contribute to the function of bacterial immune evasion proteins and reveal a surprising plasticity in the structures of borrelial C1r inhibitors.

| S-EPMC10413161 | biostudies-literature

Oms38 is the first identified pore-forming protein in the outer membrane of relapsing fever spirochetes.

Project description:Relapsing fever is a worldwide, endemic disease caused by several spirochetal species belonging to the genus Borrelia. During the recurring fever peaks, borreliae proliferate remarkably quickly compared to the slow dissemination of Lyme disease Borrelia and therefore require efficient nutrient uptake from the blood of their hosts. This study describes the identification and characterization of the first relapsing fever porin, which is present in the outer membranes of B. duttonii, B. hermsii, B. recurrentis, and B. turicatae. The pore-forming protein was purified by hydroxyapatite chromatography and designated Oms38, for outer membrane-spanning protein of 38 kDa. Biophysical characterization of Oms38 was done by using the black lipid bilayer method, demonstrating that Oms38 forms small, water-filled channels of 80 pS in 1 M KCl that did not exhibit voltage-dependent closure. The Oms38 channel is slightly selective for anions and shows a ratio of permeability for cations over anions of 0.41 in KCl. Analysis of the deduced amino acid sequences demonstrated that Oms38 contains an N-terminal signal sequence which is processed under in vivo conditions. Oms38 is highly conserved within the four studied relapsing fever species, sharing an overall amino acid identity of 58% and with a strong indication for the presence of amphipathic beta-sheets.

| S-EPMC2580676 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data