BACKGROUND: Analysis of Borrelia burgdorferi ospC types from the southeastern U.S.A. supported the common belief that various ospC types are geographically restricted and host specific. Being widely distributed in the region, the southeastern population of B. burgdorferi is represented by a surprisingly small number of ospC types. Types B, G and H are dominant or common and are invasive, while scarce type L, restricted mostly to the southeastern U.S.A., is believed to rarely if ever cause human Lyme disease. OspC type B and L strains are represented in the region at the same rate, however their distribution among tick vectors and vertebrate hosts is unequal. FINDINGS: Direct diagnostics was used to analyze the ability of B. burgdorferi ospC type L strains to disseminate into host tissues. Mice were infected by subcutaneous injections of B. burgdorferi strains of various ospC types with different invasive capability. Spirochete levels were examined in ear, heart, bladder and joint tissues. Noninfected I. ricinus larvae were fed on infected mice until repletion. Infection rates were determined in molted nymphs. Infected nymphs were then fed on naïve mice, and spirochete transmission from infected nymphs to mice was confirmed. CONCLUSIONS: B. burgdorferi ospC type L strains from the southeastern U.S.A. have comparable potential to disseminate into host tissues as ospC types strains commonly associated with human Lyme disease in endemic European and North American regions. We found no difference in the invasive ability of ospC type B and L strains originated either from tick vectors or vertebrate hosts.

• MeSH
• antigeny bakteriální genetika   metabolismus   MeSH
• Borrelia burgdorferi klasifikace   fyziologie   MeSH
• lidé MeSH
• lymeská nemoc epidemiologie   mikrobiologie   MeSH
• myši MeSH
• proteiny vnější bakteriální membrány genetika   metabolismus   MeSH
• regulace genové exprese u bakterií fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa epidemiologie   MeSH
• jihovýchod USA epidemiologie   MeSH
• Názvy látek
• antigeny bakteriální MeSH
• OspC protein MeSH Prohlížeč
• proteiny vnější bakteriální membrány MeSH

BACKGROUND: The controversy surrounding the potential impact of birds in spirochete transmission dynamics and their capacity to serve as a reservoir has existed for a long time. The majority of analyzed bird species are able to infect larval ticks with Borrelia. Dispersal of infected ticks due to bird migration is a key to the establishment of new foci of Lyme borreliosis. The dynamics of infection in birds supports the mixing of different species, the horizontal exchange of genetic information, and appearance of recombinant genotypes. METHODS: Four Borrelia burgdorferi sensu lato strains were cultured from Ixodes minor larvae and four strains were isolated from Ixodes minor nymphs collected from a single Carolina Wren (Thryothorus ludovicianus). A multilocus sequence analysis that included 16S rRNA, a 5S-23S intergenic spacer region, a 16S-23S internal transcribed spacer, flagellin, p66, and ospC separated 8 strains into 3 distinct groups. Additional multilocus sequence typing of 8 housekeeping genes, clpA, clpX, nifS, pepX, pyrG, recG, rplB, and uvrA was used to resolve the taxonomic status of bird-associated strains. RESULTS: Results of analysis of 14 genes confirmed that the level of divergence among strains is significantly higher than what would be expected for strains within a single species. The presence of cross-species recombination was revealed: Borrelia burgdorferi sensu stricto housekeeping gene nifS was incorporated into homologous locus of strain, previously assigned to B. americana. CONCLUSIONS: Genetically diverse Borrelia strains are often found within the same tick or same vertebrate host, presenting a wide opportunity for genetic exchange. We report the cross-species recombination that led to incorporation of a housekeeping gene from the B. burgdorferi sensu stricto strain into a homologous locus of another bird-associated strain. Our results support the hypothesis that recombination maintains a majority of sequence polymorphism within Borrelia populations because of the re-assortment of pre-existing sequence variants. Even if our findings of broad genetic diversity among 8 strains cultured from ticks that fed on a single bird could be the exception rather than the rule, they support the theory that the diversity and evolution of LB spirochetes is driven mainly by the host.

• MeSH
• Borrelia burgdorferi klasifikace   genetika   izolace a purifikace   MeSH
• esenciální geny MeSH
• fylogeneze MeSH
• genetická variace MeSH
• klíšťata mikrobiologie   MeSH
• molekulární sekvence - údaje MeSH
• ptáci mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Comparative analysis of ospC genes from 127 Borrelia burgdorferi sensu stricto strains collected in European and North American regions where Lyme disease is endemic and where it is not endemic revealed a close relatedness of geographically distinct populations. ospC alleles A, B, and L were detected on both continents in vectors and hosts, including humans. Six ospC alleles, A, B, L, Q, R, and V, were prevalent in Europe; 4 of them were detected in samples of human origin. Ten ospC alleles, A, B, D, E3, F, G, H, H3, I3, and M, were identified in the far-western United States. Four ospC alleles, B, G, H, and L, were abundant in the southeastern United States. Here we present the first expanded analysis of ospC alleles of B. burgdorferi strains from the southeastern United States with respect to their relatedness to strains from other North American and European localities. We demonstrate that ospC genotypes commonly associated with human Lyme disease in European and North American regions where the disease is endemic were detected in B. burgdorferi strains isolated from the non-human-biting tick Ixodes affinis and rodent hosts in the southeastern United States. We discovered that some ospC alleles previously known only from Europe are widely distributed in the southeastern United States, a finding that confirms the hypothesis of transoceanic migration of Borrelia species.

• MeSH
• alely * MeSH
• antigeny bakteriální genetika   MeSH
• Borrelia burgdorferi genetika   izolace a purifikace   MeSH
• DNA bakterií chemie   genetika   MeSH
• genetická variace MeSH
• genotyp MeSH
• hlodavci mikrobiologie   MeSH
• klíště mikrobiologie   MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• proteiny vnější bakteriální membrány genetika   MeSH
• sekvenční analýza DNA MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, P.H.S. MeSH
• Geografické názvy
• Evropa MeSH
• Severní Amerika MeSH
• Názvy látek
• antigeny bakteriální MeSH
• DNA bakterií MeSH
• OspC protein MeSH Prohlížeč
• proteiny vnější bakteriální membrány MeSH