The ixodid tick Ixodes persulcatus is the most important vector of Lyme disease in Japan. Most spirochete isolates obtained from I. persulcatus ticks have been classified as Borrelia burgdorferi sensu lato because of their genetic, biological, and immunological characteristics. However, we found that a small number of isolates obtained from I. persulcatus contained a smaller 38-kDa endoflagellar protein and single 23s-5s rRNA gene unit. Representative isolate HT31T (T = type strain) had the same 23s rRNA gene physical map as Borrelia turicatae. The DNA base composition of strain HT31T was 28.6 mol% G+C. DNA-DNA hybridization experiments revealed that strain HT31T exhibited moderate levels of DNA relatedness (24 to 51%) with Borrelia hemsii, B. turicatae, Borrelia parkeri, and Borrelia coriaceae. However, the levels of DNA reassociation with the previously described Lyme disease borreliae (B. burgdorferi, Borrelia garinii, and Borrelia afielii) were only 8 to 13%. None of the previously described species examined exhibited a high level of DNA relatedness with strain HT31T. In addition, the 16s rRNA gene sequence (length, 1,368 nucleotides) of strain HT31T was determined and aligned with the 16s rRNA sequences of other Borrelia species. Distance matrix analyses were performed, and a phylogenetic tree was constructed. The results showed that isolate HT31T is only distantly related to both previously described Lyme disease borreliae and relapsing fever borreliae. Thus, the spirochetes isolated from I. persulcatus and closely related isolates should be classified as members of a new Borrelia species. We propose the name Borrelia rniyamotoi sp. nov. for this spirochete; strain HT31 is the type strain.We previously demonstrated the usefulness of a restriction fragment length polymorphism (RFLP) ribotyping system based on the 23s-5s rRNA gene repetition in Borrelia burgdorferi sensu lato associated with Lyme disease (14, 32). Many spirochete isolates were examined with our RFLP ribotyping system by using rRNA gene probes. The strains isolated in the United States and Europe were placed into three distinct RFLP groups. The North American isolates clustered in ribotype group I (B. burgdo$eri sensu stricto), and the European isolates were placed in ribotype groups I and I1 (Borrelia garinii) and ribotype group I11 (Borrelia afielii). These groups are completely consistent with the three previously described Lyme disease agent species (2,7,18). Our findings also showed that there are no B. burgdorferi sensu stricto representative strains in Japan and that some Japanese isolates belong to ribotype groups I1 and 111. In addition, most of the Japanese isolates produced RFLP patterns that were quite distinct from those of the North American and European isolates and were tentatively classified as ribotype group IV strains (14). Borrelia japonica is carried by Ixodes ovatus ticks, and it is thought that this microorganism is restricted to Japan. Moreover, some atypical spirochetes have been isolated in United States and Europe (...
Lee et al. demonstrate that mannose receptor–mediated infection of M2-like dermal macrophages plays a critical role in nonhealing cutaneous infection by L. major. The dermal macrophages are radio resistant and self-renewed and efficiently maintain their M2 phenotype during Th1 immunity.
Reference strains from 48 selected serovars representing eight species of Leptospira were examined by two polymerase chain reaction (PCR)-based strategies. First, mapped restriction site polymorphisms (MRSP) were examined in PCR products from portions of rrs (16S rRNA gene) and rrl (23S rRNA gene). Twenty MRSP and 2 length polymorphisms were used to group reference strains into 16 MRSP profiles. Species assignments were consistent with those obtained by a second method, genomic fingerprinting with arbitrarily primed PCR, in which strains within a species were characterized by many shared arbitrarily primed PCR products. The results of both of these methods were in general agreement with those of previous studies that used DNA-DNA relatedness and confirmed the high level of divergence among the recognized species of Leptospira. However, Leptospira meyeri serovar ranarum and evansi strains were indistinguishable from some strains of Leptospira interrogans sensu stricto. Intervening sequences of about 485 to 740 bp were located near base 1230 in rrl of some strains.
Success rates for genomic analyses of highly heterogeneous disorders can be greatly improved if a large cohort of patient data is assembled to enhance collective capabilities for accurate sequence variant annotation, analysis, and interpretation. Indeed, molecular diagnostics requires the establishment of robust data resources to enable data sharing that informs accurate understanding of genes, variants, and phenotypes. The “Mitochondrial Disease Sequence Data Resource (MSeqDR) Consortium” is a grass-roots effort facilitated by the United Mitochondrial Disease Foundation to identify and prioritize specific genomic data analysis needs of the global mitochondrial disease clinical and research community. A central Web portal (https://mseqdr.org) facilitates the coherent compilation, organization, annotation, and analysis of sequence data from both nuclear and mitochondrial genomes of individuals and families with suspected mitochondrial disease. This Web portal provides users with a flexible and expandable suite of resources to enable variant-, gene-, and exome-level sequence analysis in a secure, Web-based, and user-friendly fashion. Users can also elect to share data with other MSeqDR Consortium members, or even the general public, either by custom annotation tracks or through use of a convenient distributed annotation system (DAS) mechanism. A range of data visualization and analysis tools are provided to facilitate user interrogation and understanding of genomic, and ultimately phenotypic, data of relevance to mitochondrial biology and disease. Currently available tools for nuclear and mitochondrial gene analyses include an MSeqDR GBrowse instance that hosts optimized mitochondrial disease and mitochondrial DNA (mtDNA) specific annotation tracks, as well as an MSeqDR locus-specific database (LSDB) that curates variant data on more than 1,300 genes that have been implicated in mitochondrial disease and/or encode mitochondria-localized proteins. MSeqDR is integrated with a diverse array of mtDNA data analysis tools that are both freestanding and incorporated into an online exome-level dataset curation and analysis resource (GEM.app) that is being optimized to support needs of the MSeqDR community. In addition, MSeqDR supports mitochondrial disease phenotyping and ontology tools, and provides variant pathogenicity assessment features that enable community review, feedback, and integration with the public ClinVar variant annotation resource. A centralized Web-based informed consent process is being developed, with implementation of a Global Unique Identifier (GUID) system to integrate data deposited on a given individual from different sources. Community-based data deposition into MSeqDR has already begun. Future efforts will enhance capabilities to incorporate phenotypic data that enhance genomic data analyses. MSeqDR will fill the existing void in bioinformatics tools and centralized knowledge that are necessary to enable efficient nuclear and mtDNA genomic data interpretation by a range of shareholders across bo...
An intervening sequence (IVS) occurred in the 23S rRNA genes (rrl) of some, but not all, strains of four species of the spirochete genus Leptospira and was absent from strains in three other species. The IVS varied in size from 485 to 759 base pairs and replaced bases 1224-1245 in both copies of rrl. The two ends of each IVS shared 22-35 bases of complementarity that could form a stable double helix. The presence of an IVS correlated with a cleaved mature 23S rRNA that probably results from removal of the IVS without religation. The 3' site of cleavage was mapped within the inverted repeat of the IVS. An open reading frame of 121-133 amino acids was conserved in the IVS in anl four species, oriented so that the sense strand was in the rRNA transcript. When the open reading frames were compared between species, they predicted polypeptides that showed between 51% and 78% amino acid conservation and similar DNA sequence conservation, indicating selection for protein function.
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