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D Postic

Publications and source records attributed to D Postic.

At least 37 records · Page 2Linked to original sources
PubMed1998

Expanded diversity among Californian borrelia isolates and description of Borrelia bissettii sp. nov. (formerly Borrelia group DN127).

Up to now, the only species in the complex Borrelia burgdorferi sensu lato known to cause Lyme borreliosis in the United States has been B. burgdorferi sensu stricto. However, some atypical strains closely related to the previously designated genomic group DN127 have been isolated in the United States, mostly in California. To explore the diversity of B. burgdorferi sensu lato group DN127, we analyzed the nucleotide sequences of the rrf-rrl intergenic spacer regions from 19 atypical strains (18 from California and one from New York) and 13 North American B. burgdorferi sensu stricto strains (6 from California). The spacer region sequences from the entire B. burgdorferi sensu lato complex available in data banks were used for comparison. Phylogenetic analysis of sequences shows that the main species of the B. burgdorferi sensu lato complex (B. afzelii, B. garinii, B. andersonii, B. japonica, B. burgdorferi sensu stricto, B. valaisiana, and B. lusitaniae) each form a coherent cluster. A heterogeneous group comprising strains belonging to the previously designated group DN127 clustered separately from B. burgdorferi sensu stricto. Within this cluster, the deep branches expressing the distances between the rrf-rrl sequences reflect a high level of divergence. This unexpected diversity contrasts with the monomorphism exhibited by B. burgdorferi sensu stricto. To clarify the taxonomic status of this highly heterogeneous group, analysis of the rrs sequences of selected strains chosen from deeply separated branches was performed. The results show that these strains significantly diverge at a level that is compatible with several distinct genomic groups. We conclude that the taxonomy and phylogeny of North American B. burgdorferi sensu lato should be reevaluated. For now, we propose that the genomic group DN127 should be referred to as a new species, B. bissettii sp. nov., and that other related but distinct strains, which require further characterization, be referred to as Borrelia spp.

Borrelia↗
PubMed1998

An avian reservoir (Turdus merula) of the Lyme borreliosis spirochetes.

The reservoir competence of passerine birds for the Lyme borreliosis spirochetes was studied in an enzootic focus in Switzerland. Skin aspirates and skin biopsies were used to isolate Borrelia spirochetes from Turdus species. B. burgdorferi sensu lato was isolated and/or PCR-detected in BSK medium containing skin biopsy or skin aspirate from 5 blackbirds (T. merula) and one song thrush (T. philomelos). Seven isolates were obtained from 3 different blackbirds. Either B. garinii or Borrelia from the genomic group VS116 was found in bird skin samples. Mixed infection occurred in 2 cases. Tick xenodiagnosis was used to determine whether blackbirds transmitted Borrelia to ticks. Five xenodiagnoses were performed on 3 different blackbirds. Borrelia DNA was detected in BSK medium inoculated with xenodiagnostic ticks from all the passerines tested. Isolates cultured from xenodiagnostic ticks were obtained from 2 blackbirds. Isolates belonged to group VS116 (n = 10) and to B. garinii (n = 1). Our study has shown that Turdus sp. are infected by B. garinii and by Borrelia from group VS116 and that blackbirds are implicated as reservoirs for these 2 genomic groups of Borrelia, as they transmit living borreliae to ticks. An association seems to exist between birds and Borrelia VS116, and to a lesser extent, B. garinii, similar to the association existing between small rodents and B. afzelii. Our observations emphasize the fact that different enzootic cycles maintain Lyme borreliosis spirochetes in nature.

Animals↗
PubMed1998

[Borrelia burgdorferi, taxonomy, pathogenicity and spread].

Borrelia burgdorferi sensu lato is a bacterial complex of at least 10 species, most of which are non pathogenic for humans. Non pathogenic species seem to be more vector-specific, their distribution being restricted to that of this vector. In opposition, the three species pathogenic for humans, Borrelia burgdorferi sensu stricto (B.b.s.s.), Borrelia garinii (B.g.), and Borrelia afzelii (B.a.), are transmitted by several species of ticks more diversified in their host choice. Each of these three species is associated with a preferential organotropism: articulation for B.b. s.s., neurologic system for B.g. and skin for B.a. Strains belonging to these three species are much more frequently isolated from vectors and have a much larger area of expansion than the non pathogenic species. Indeed, their geographical distribution corresponding to that of their vector comprises one or two continents. B.g. and B.a., transmitted by Ixodes ricinus and Ixodes persulcatus, are spread throughout Eurasia. B.b. s.s. is the only species spread on two continents separated by an Ocean: North America (vectors: I. scapularis and I. pacificus) and Europe (I. ricinus). Combining of epidemiological data and molecular analyses shows that B.b. s.s. probably originated in America and later on, very recently (after 1492), migrated to the European continent.

Animals↗
PubMed1997

Borrelia burgdorferi sensu lato in Russia and neighbouring countries: high incidence of mixed isolates.

A total of 365 isolates of Borrelia burgdorferi sensu lato from 12 major administrative territories of Russia (from St. Petersburg in the west to South Sakhalin in the east) and from the Czech Republic, Estonia, Lithuania, Byelorussia, Moldavia, Ukraine and Kirghizia were identified by analysis of restriction polymorphism of ribosomal rrf-rrl spacer amplicons. The isolates were obtained mainly from ixodes persulcatus and I. ricinus ticks. Other sources included small mammals, human patients and I. trianguliceps ticks. The results showed that B. garinii (two variants) together with B. afzelii circulated throughout the territories studied. The distribution of the variant NT29 of the species B. garinii, the most frequently isolated, was associated with that of I. persulcatus ticks. B. burgdorferi sensu stricto, and the species B. valaisiana and B. lusitaniae (formerly the genomospecies VS116 and PotiB2, respectively) were isolated only from I. ricinus ticks in the western part of the studied territories. None of these three species were found in 327 isolates from Russia where I. persulcatus is the most frequently distributed vector. This work also provides evidence for a high incidence of mixed Borrelia infections within vectors and hosts (9.3% of isolates were mixtures of Borrelia species). A detailed analysis of Borrelia species distribution over the territories studied is presented.

Animals↗
PubMed1997

Phylogenetic analysis of Borrelia burgdorferi sensu stricto by arbitrarily primed PCR and pulsed-field gel electrophoresis.

Borrelia burgdorferi sensu lato is present all over the world. However, most species belonging to this complex have a limited distribution; the only exception is B. burgdorferi sensu stricto, which is encountered both in Europe and in the United States. The aim of this study was to clarify the way that B. burgdorferi sensu stricto migrated. To do this, we compared the genetic polymorphism of 33 B. burgdorferi sensu stricto strains isolated in Europe and 28 strains isolated in the United States by using both pulsed-field gel electrophoresis and arbitrarily primed PCR. Phylogenetic analysis of each of the two sets of data was performed by a genetic distance method and a parsimony method. The results were consistent and revealed that the American strains were more heterogeneous than the European strains. The hypothesis that B. burgdorferi sensu stricto was introduced to Europe from America rather than vice versa has to be considered.

Animals↗
PubMed1997

Recognition of two new species of intestinal spirochetes: Serpulina intermedia sp. nov. and Serpulina murdochii sp. nov.

On the basis of DNA-DNA hybridization data, nine intestinal spirochete strains were grouped into five genospecies. Three of these genospecies were previously recognized Serpulina species, Serpulina hyodysenteriae (type strain, B78), Serpulina innocens (type strain, B256), and Serpulina pilosicoli (type strain, P43/6/78; previously "Anguillina coli"). The other two genospecies were found to be new Serpulina species, for which we propose the names Serpulina intermedia sp. nov. (with type strain PWS/A) and Serpulina murdochii sp. nov. (with type strain 56-150). S. intermedia and S. murdochii cells had a typical spirochete ultrastructure with 22 to 28 periplasmic flagella per cell. Various soluble sugars were growth substrates for S. intermedia and S. murdochii. During growth in basal heart infusion broth supplemented with fetal calf serum beneath an O2-N2 (1:99) atmosphere, cells of these new species consumed oxygen and glucose and produced H2, CO2, acetate, butyrate, and ethanol. The G + C content of the DNA of S. murdochii 56-150T was 27 mol%, and the G + C content of the DNA of S. intermedia PWS/AT was 25 mol%. In addition, a restriction fragment length polymorphism-PCR assay for the detection of intestinal spirochetes was developed. The assay was based on generation and restriction endonuclease analysis (with HinfI, TaqI, Sau3A, and MboII) of a 558-bp amplicon of ribosomal DNA (rDNA) encoding 16S rRNA. The PCR amplification was specific for Serpulina species and Brachyspira aalborgi. Four restriction digest patterns were found for the five Serpulina species. HinfI restriction differentiated S. murdochii and S. innocens from the other species. Sau3A and TaqI restrictions gave unique fragment patterns for S. murdochii and S. pilosicoli, respectively. S. hyodysenteriae and S. intermedia DNAs gave the same fragment pattern regardless of the enzyme tested. B. aalborgi was differentiated from the Serpulina species by MboII digestion of the 16S rDNA amplicon.

Bacterial Proteins↗
PubMed1997

Borrelia burgdorferi sensu stricto, a bacterial species "made in the U.S.A."?

Among the three main species of Borrelia burgdorferi sensu lato associated with Lyme borreliosis, B. burgdorferi sensu stricto (B. burgdorferi) is the sole species present both in North America and in Europe, where Borrelia garinii and Borrelia afzelii also occur. The greater genetic diversity together with the greater clinical polymorphism observed in the Old World suggests that this is the birthplace of the complex B. burgdorferi sensu lato. However, the genetic proximity of some North American and European B. burgdorferi strains in quite mystifying. A previous study of the whole genome (M. Foretz, D. Postic, and G. Baranton, Int. J. Syst. Bacteriol. 47:11-18, 1997) compared the diversity of North American and European B. burgdorferi strains. To further investigate the geographical origin and the migration of B. burgdorferi, we have focused on the study of the single variable and highly adaptive gene ospC. Both approaches demonstrated the greater diversity of North American strains and the close relatedness between European strains and between some isolates from the two areas. We discuss the significance of these features and suggest that they might be evidence of the anteriority of North American B. burgdorferi strains.

Amino Acid Sequence↗
PubMed1997

Characterization of Borrelia lusitaniae sp. nov. by 16S ribosomal DNA sequence analysis.

We determined the complete sequence of the rrs gene from five strains of genomic species PotiB2. Both distance and parsimony methods were used to infer the evolutionary relationships of the rrs gene sequence of this genomic species in comparison with the rrs gene sequence of Borrelia valaisiana and the rrs gene sequences of Borrelia burgdorferi sensu lato species obtained from sequence databases. The phylogenetic analysis revealed that the genomic species PotiB2 strains clustered in a separate lineage, which was consistent with data from previous DNA-DNA hybridization experiments (D. Postic, M. V. Assous, P. A. D. Grimont, and G. Baranton, Int. J. Syst. Bacteriol. 44:743-752, 1994). A PCR-restriction fragment length polymorphism analysis was used to identify genomic species PotiB2 and to differentiate it from B. burgdorferi sensu lato species. Moreover, signature nucleotide positions were identified for each B. burgdorferi sensu lato species. In accordance with DNA relatedness values, our findings suggest that genomic species PotiB2 can be more clearly defined and identified, and we propose that it should be referred to as a new species, Borrelia lusitaniae. The type strain is PotiB2.

Bacterial Proteins↗
PubMed1997

Genetic and phenotypic analysis of Borrelia valaisiana sp. nov. (Borrelia genomic groups VS116 and M19).

To clarify the taxonomic status of two recently described Borrelia genomic groups, groups VS116 and M19, three group VS116 strains and eight group M19 strains isolated from Ixodes ricinus ticks in Switzerland, The Netherlands, and the United Kingdom were characterized. PCR-restriction fragment length polymorphism (RFLP) analysis of the 5S-23S intergenic spacer amplicon, rRNA gene restriction analysis, 16S rRNA gene sequence analysis, randomly amplified polymorphic DNA (RAPD) fingerprinting, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and immunoblotting with monoclonal antibodies were used for genetic and phenotypic analysis. The PCR-RFLP and RAPD patterns of three group VS116 strains and eight group M19 strains were identical but differed from those of Borrelia burgdorferi sensu stricto, Borrelia garinii, Borrelia afzelii, and Borrelia japonica. DNAs from all group VS116 and M19 strains yielded three fragments (6.9, 3.2, and 1.4 kb) and four fragments (2.1, 1.2, 0.8, and 0.6 kb) after digestion with EcoRV and HindIII, respectively, hybridizing with an Escherichia coli 16S + 23S cDNA probe. The SDS-PAGE protein profiles of group VS116 and M19 strains were heterogeneous. Phylogenetic analysis of the partial 16S rRNA gene sequences showed that group VS116 and M19 spirochetes were members of a Borrelia species distinct from previously characterized members of the genus Borrelia. Based on our present study and data from previous DNA-DNA hybridizations, a new Borrelia species, Borrelia valaisiana sp.nov., in the B. burgdorferi complex, is proposed. Strain VS116 is the type strain of this new species.

Bacterial Proteins↗
PubMed1996

Infection of Ixodes ricinus (Acari:Ixodidae) by Borrelia burgdorferi in Ile de France.

Free-living nymphs and adults from Rambouillet and Fontainebleau, 2 major forests of Ile de France, were collected to determine the infection rates of Ixodes ricinus L. by Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt & Brenner). Field-collected I. ricinus nymphs and adults were screened for the presence of B. burgdorferi using direct fluorescent antibody assay. The infection rates of nymph, male and female were 12.4% (314), 2.8% (35), and 2.9% (34). No difference in infection rates of nymphs among sites were detected. Spirochetes was isolated from both sites. Isolates from Rambouillet and Fontainebleau were identified as B. burgdorferi sensu stricto and B. garinii, respectively (Baranton, Postic, Saint-Girons, Boerlin, Piffaretti, Assous, and Grimont).

Animals↗
PubMed1996

Phylogenesis of relapsing fever Borrelia spp.

The phylogenetic relationships of 20 relapsing fever (RF) Borrelia spp. were estimated on the basis of the sequences of rrs genes. Complete sequences were aligned and compared with previously published sequences, and the similarity values were found to be 97.7 to 99.9%. Phylogenetic trees were constructed by using the three neighbor-joining, maximum-parsimony, and maximum-likelihood methods. The results of the comparative phylogenetic analysis divided the RF Borrelia spp. into three major clusters. One cluster included Borrelia crocidurae, Borrelia duttonii, Borrelia recurrentis, and Borrelia hispanica. Another cluster comprised tow main branches with Borrelia coriaceae, Borrelia lonestari, and Borrelia miyamotoi on one side and Borrelia parkeri, Borrelia turicatae, and Borrelia hermsii on the other side. Borrelia anserina constituted the third cluster. The phylogenetic position of Borrelia persica was more uncertain. These results suggested that the taxonomy of these spirochetes should be revised. To overcome the problems of culturing the spirochetes, RF Borrelia primers were defined. Following PCR amplification of the rrs gene, restriction length fragment polymorphism could be used to distinguish between RF Borrelia strains.

Animals↗
PubMed1996

Borrelia burgdorferi sensu lato in an endemic environment: wild sika deer (Cervus nippon yesoensis) with infected ticks and antibodies.

Ticks and blood samples were collected from wild sika deer (Cervus nippon yesoensis) during a hunting season (August to October) of 1991 at a selected location in Hokkaido, Japan. Ixodes persulcatus (adult and nymph) and I. ovatus (adult) were the common ticks on sika deer. Spirochetes were detected in the midgut of the ticks by the indirect peroxidase-conjugated antibody staining method and by dark-field microscopy after cultivation. By the reactive pattern of monoclonal antibodies, isolates were considered to belong to Borrelia garinii or B. japonica. In an antibody test, the percentage of seropositive deer was 69.0%. Most of the adult sika deer were positive for antibodies to the spirochetes. There are significant age-dependency in antibody level and seropositive rate. The surveillance of deer should be valuable in monitoring the transmission risk of B. burgdorferi sensu lato in nature.

Age Factors↗
PubMed1996

Platelet-activating-factor-mediated pathogenesis in Lyme disease.

This study describes a role of platelet-activating factor (PAF) as a potential inducer of inflammation in infection with Borrelia burgdorferi. Two approaches were taken. The first involved the use of a PAF antagonist to show the lack of an inflammatory response in skin lesions. The second was to show that the PAF antagonist reduced platelet aggregation when the spirochetes were incubated with polymorphonuclear leukocytes.

Animals↗
PubMed1994

Individualisation of two new genomic groups among American Borrelia burgdorferi sensu lato strains.

We developed a quick typing method for Borrelia burgdorferi sensu lato strains using a fla gene-based PCR assay, followed by dot blot hybridization with non-radioactive species-specific probes. Thirty-six out of 46 strains belonged to one of the four described species (B. burgdorferi sensu stricto n = 11, B. garinii n = 11, B. afzelii n = 9 and B. japonica n = 5) and hybridized with its own species-specific probe. Among the 10 remaining American strains, two new additional genomic groups were identified. This finding was confirmed by direct sequencing of the fla gene-derived amplicons and whole DNA hybridization.

Animals↗
PubMed1994

[Research of Lyme's disease in facial paralysis. A French multicenter study].

OBJECTIVES: Apparent a frigore facial palsy could possibly mask manifestations of unrecognized Lyme's disease. Since commonly used corticosteroid treatment could be deleterious if Borrelia burgdorferi infection was indeed the cause, we conducted a prospective study to search for possible infections in cases of recently diagnosed a frigore facial palsy. METHODS: For 3 years, 1990-1992, 49 French centres diagnosed a facial palsy in 346 patients (310 adults, 36 children under 15 years of age; mean age 38; range 16 months to 83 years). The patients were divided into three groups: a) facial palsy alone, b) zoster origin recognized due to outer ear eruption and c) cases with meningoradiculitis or joint signs or cases with facial diplegia. A questionnaire was used to evaluate exposure to risk of tick bits. A control group was established with 246 serum samples from subjects matched with the patients for age, geographical origin and exposure to risk of tick bits. Laboratory tests (indirect immunofluorescence and Western blot) were performed to search for anti-Borrelia burgdorferi antibodies in serum samples, and cerebral spinal fluid when possible, collected at presentation, on day 30 and on day 90. RESULTS: Sixty percent of the patients were urban dwellers, 15% lived in rural and 25% in semi-rural areas. There were 294 patients with facial palsy alone and their serum results were compared with those of the matched controls. There was no significant difference in the positivity for Borrelia burgdorferi antibodies between these two groups. CONCLUSION: These findings indicate that, unless there are clinical signs suggestive of borreliosis, it would not be necessary to test for Lyme's disease in patients with apparent a frigore facial palsy.

Adolescent↗
PubMed1994

Diversity of Borrelia burgdorferi sensu lato evidenced by restriction fragment length polymorphism of rrf (5S)-rrl (23S) intergenic spacer amplicons.

The organization of the ribosomal genes is unique in Borrelia burgdorferi in that the rrl (23S) and rrf (5S) genes are tandemly duplicated. We took advantage of this uniqueness to assess the restriction polymorphism of PCR products obtained with primers at the 3' end of the first rrf gene and at the 5' end of the second rrl gene. An amplicon that was 226 to 266 bp long was generated from 99 to 100 B. burgdorferi sensu lato strains. The nuclease MseI restriction polymorphism of the amplicons provided a useful tool for identifying B. burgdorferi sensu stricto, Borrelia garinii, Borrelia afzelii (formerly group VS461), and Borrelia japonica (formerly group F63B). Furthermore, it allowed us to recognize four new genomic groups, which were confirmed by DNA-DNA hybridization data. Two of these genomic groups comprised European strains, and the other two groups contained American strains. The American genomic groups involved vectors with enzootic cycles quite different from those of B. burgdorferi sensu stricto, which previously was the only Lyme disease Borrelia species known to occur in the United States. Our method could be used for rapid screening of strain collections and for epidemiological and medical purposes.

Base Sequence↗