| [incidence of borrelia burgdorferi sensu lato spirochetes in ixodes ricinus ticks from a museum collection evaluated by pcr]. | ixodes ricinus ticks (total n = 51:14 larvae, 16 nymphs, 17 females and 11 males) collected at 21 different sites during 1948-1987 were examined individually for the presence of borrelia burgdorferi sensu lato spirochaetes. detection of spirochaetes was carried out by polymerase chain reaction (pcr) using primers complementary to chromosomal sequence. borreliae were found in 3 (3.56%) examined ticks (nymphs) collected at the same site (two in june, 1952 and one in august, 1987). the low number o ... | 1997 | 9562792 |
| identification of borrelia burgdorferi sensu lato species in europe. | characterisation at the species level of 142 borrelia isolates obtained from ticks, humans and rodents in western europe was carried out and their geographical distribution was described. borrelia garinii was the predominant species representing 44% of the isolates and b. afzelii and b. burgdorferi sensu stricto constituted 27% and 19% of isolates respectively. b. valaisiana, (formerly group vs116) constituted 10.5% of isolates. some differences in the borrelia species distribution were observed ... | 1998 | 9563195 |
| detection of borrelia burgdorferi sensu lato in ticks: immunofluorescence assay versus polymerase chain reaction. | immunofluorescence (ifa) and polymerase chain reaction (pcr) were examined as methods for detecting borrelia burgdorferi sensu lato spirochaetes in unfed ixodes ricinus nymphs. although similar results were produced in some cases, a great deal of variation occurred. furthermore, in both the highly controlled initial laboratory study, involving 252 shared samples, and the study on field-collected ticks (n = 460), the ifa tended to detect more infected ticks than the pcr. the basis for these findi ... | 1998 | 9563196 |
| diversity of european lyme disease spirochetes at the southern margin of their range. | we determined whether the genospecies diversity of lyme disease spirochetes in vector ticks questing on a subtropical island is as broad as that in central europe. although spirochetes infected < 1% of the ticks sampled on madeira island, these infections included all three genospecies implicated in human disease. therefore, spirochetal diversity is as great at the southern margin as it is in the center of this pathogen's range. | 1998 | 9572986 |
| structure and expression of the flaa periplasmic flagellar protein of borrelia burgdorferi. | the spirochete which causes lyme disease, borrelia burgdorferi, has many features common to other spirochete species. outermost is a membrane sheath, and within this sheath are the cell cylinder and periplasmic flagella (pfs). the pfs are subterminally attached to the cell cylinder and overlap in the center of the cell. most descriptions of the b. burgdorferi flagellar filaments indicate that these organelles consist of only one flagellin protein (flab). in contrast, the pfs from other spirochet ... | 1998 | 9573194 |
| first characterization of borrelia burgdorferi sensu lato from ticks and skin biopsy in bulgaria. | lyme borreliosis is the most frequent tick-borne disease in the northern hemisphere. here we describe the first isolation of borrelia burgdorferi sensu lato in bulgaria: the midguts of 47 ixodes ricinus obtained by flagging from the central park in sofia, bulgaria were cultivated for borreliae in bsk medium. the eight isolates obtained from the ticks and one skin isolate from a bulgarian patient with erythema migrans were subjected to phenotypic [outer surface protein a (ospa) serotyping] and ge ... | 1998 | 9574899 |
| ixodes ricinus strains in europe. | an analysis of cuticular hydrocarbons (ch) of unfed adult ixodes ricinus ticks collected throughout europe showed that there are 10 distinct i. ricinus groups. studies on the seasonal and annual consistency of ch composition and possible effects of host and environmental factors suggested that chs may be used as a genuine genetic marker for i. ricinus. preliminary studies compared the vector competence of ticks from three of the most separated i. ricinus groups and the results suggested that the ... | 1998 | 9580422 |
| interstadial variation in the attachment sites of ixodes ricinus ticks on sheep. | the spatial aggregation of ticks feeding on vertebrate hosts has been recognized for some time but, for hosts supporting more than one stage of the tick, observations of interstadial variation in the site of attachment have not previously been quantified. this study showed that all three parasitic stages of ixodes ricinus ticks feeding on sheep attach most commonly to the hair-covered areas of the head and limbs while few ticks attach to the fleeced region of the body. however, significant diffe ... | 1998 | 9588009 |
| borrelia burgdorferi escape mutants that survive in the presence of antiserum to the ospa vaccine are killed when complement is also present. | as an initial attempt to investigate the possible role of outer surface protein a (ospa) escape mutants of borrelia burgdorferi in decreasing the efficacy of the ospa vaccine, mutants of the hb19 strain of b. burgdorferi sensu stricto were selected in vitro from an uncloned, low-passage-number isolate. the antiserum used for selection was obtained from rhesus monkeys that had been given a vaccine of the same formulation and dose, and by the same route of administration, as that given to humans i ... | 1998 | 9596714 |
| borrelia burgdorferi erp proteins are immunogenic in mammals infected by tick bite, and their synthesis is inducible in cultured bacteria. | borrelia burgdorferi, the causative agent of lyme disease, can contain multiple genes encoding different members of the erp lipoprotein family. some arthropod-borne bacteria increase the synthesis of proteins required for transmission or mammalian infection when cultures are shifted from cool, ambient air temperature to a warmer, blood temperature. we found that all of the erp genes known to be encoded by infectious isolate b31 were differentially expressed in culture after a change in temperatu ... | 1998 | 9596729 |
| genotypic identification of an undescribed spotted fever group rickettsia in ixodes ricinus from southwestern spain. | an undescribed rickettsia was directly analyzed with specific rickettsial molecular biology tools on ixodes ricinus l. collected in different localities of the province of cadiz (southwestern spain). on the basis of the results of the citrate synthase (glta) gene, 190 kd-outer membrane protein (rompa) gene, and 16s ribosomal rna (16s rrna) gene partial sequence data, it was found that this rickettsia is sufficiently genetically distinct from other rickettsia to be considered a distinct taxonomic ... | 1998 | 9598443 |
| seasonal variation in the role of grey squirrels as hosts of ixodes ricinus, the tick vector of the lyme disease spirochaete, in a british woodland. | data are presented on the variable patterns of the seasonal dynamics of ixodes ricinus l. ticks seen questing on the vegetation and feeding on small rodents (mice and voles) and squirrels within a british woodland focus of lyme borreliosis. information on tick infestation levels on pheasants is also presented. the results show a prolonged, unimodal pattern of tick activity, with ticks feeding throughout the year in this sheltered habitat. if host density is taken into account, squirrels are quan ... | 1995 | 9599431 |
| epidemiologic, ecologic and clinical characteristics of lyme borrelliosis in northwest croatia. | investigated were the epidemiologic, ecologic and clinical characteristics of lyme borreliosis in northwest croatia. in a seroepidemiologic study, human sera were analyzed by indirect immunofluorescent assay (ifa), and ten out of 134 serum samples were positive for b. burgdorferi antibodies. in a seroepizootiologic study, wildlife and domestic animals were tested by inhibition elisa. antibodies to b. burgdorferi were found in nine out of 42 roe deer sera, and in three out of nine hare sera. sera ... | 1998 | 9599811 |
| serological, hematologic, and pcr studies of cattle in an area of switzerland in which tick-borne fever (caused by ehrlichia phagocytophila) is endemic. | the purpose of this study was to examine the seasonal variations in seroprevalence to ehrlichia phagocytophila in cattle pastured during the summer months in an area where tick-borne fever is endemic. the study was performed during a 1-year period from april 1996 to march 1997 and involved 34 cows, 22 pregnant heifers, and 14 calves. blood samples, collected from all 70 cattle once a month, were used to determine serum immunoglobulin g titers by indirect immunofluorescence. in addition, blood sm ... | 1998 | 9605986 |
| transmission of tick-borne bunyaviruses by cofeeding ixodid ticks. | palma and bhanja bunyaviruses replicated in dermacentor marginatus, d. reticulatus, rhipicephalus sanguineus, r. appendiculatus and ixodes ricinus ticks after parenteral inoculation and appropriate incubation and feeding. palma virus was transmitted to d. marginatus and d. reticulatus males, d. reticulatus and r. sanguineus females, and r. appendiculatus nymphs while cofeeding with infected ticks on laboratory mice. bhanja virus was transmitted to d. marginatus males and r. appendiculatus nymphs ... | 1997 | 9607090 |
| detection of spotted fever group (sfg) rickettsia in ixodes ricinus ticks in austria. | | 1997 | 9607097 |
| susceptibility of balb/c mice to nymphs and larvae of ixodes ricinus after modulation of ige production with anti-interleukin-4 or anti-interferon-gamma monoclonal antibodies. | balb/c mice infested three times with nymphs or larvae of ixodes ricinus ticks do not acquire resistance as assessed by evaluation of both tick attachment and the weight of engorged nymphs or larvae. tick challenge causes a gradual increase in total ige antibody production from the first to the third infestation. anti-tick igg antibodies are never detected. when the mice are treated with anti-interleukin-4 (anti-il-4) or anti-interferon-gamma (anti-ifn-gamma) monoclonal antibodies (mabs) 1 day b ... | 1998 | 9610636 |
| suppressive effect of ixodes ricinus salivary gland extract on mechanisms of natural immunity in vitro. | tick saliva has been shown to contain a variety of pharmacologically active molecules, including those with immunosuppressive activities. there is increasing evidence that the nonspecific suppression of host immunity by tick saliva is exploited by tick-borne pathogens, e.g. the saliva-activated transmission (sat) of some tick-borne viruses. we have demonstrated the suppressive effect of the salivary gland extract (sge) derived from partially fed (five days) ixodes ricinus females on important me ... | 1998 | 9618727 |
| rate of infection of ixodes ricinus ticks with borrelia burgdorferi sensu stricto, borrelia garinii, borrelia afzelii and group vs116 in an endemic focus of lyme disease in italy. | a study to evaluate the natural rate of infection of ixodes ricinus with borrelia burgdorferi sensu lato was carried out in an endemic focus of lyme disease in the trieste area in northern italy. two-hundred and twenty-seven ticks collected in ten different stations were tested individually for the presence of the spirochetes using polymerase chain reaction techniques able to identify both borrelia burgdorferi sensu lato and the four genospecies (borrelia burgdorferi sensu stricto, borrelia gari ... | 1998 | 9629972 |
| first isolation of rickettsia helvetica from ixodes ricinus ticks in france. | two rickettsial isolates recovered from ixodes ricinus ticks in puy-de-dôme (central france) were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, western blot immunoassay, restriction fragment length polymorphism analysis, and sequencing of a portion of the citrate-synthase gene. by these methods, the isolates appeared to be identical to a member of the spotted fever group rickettsiae, rickettsia helvetica. this first isolation of rickettsia helvetica in france has ep ... | 1998 | 9629973 |
| prevalence of borrelia burgdorferi infection in ixodes ricinus in central italy. | | 1998 | 9629984 |
| relationship between borrelia burgdorferi sensu lato species, red squirrels (sciurus vulgaris) and ixodes ricinus in enzootic areas in switzerland. | the infection and reservoir status of red squirrels (sciurus vulgaris) for borrelia burgdorferi sensu lato were studied in switzerland. b. burgdorferi sensu lato was isolated from 15 skin samples from 4/6 dead red squirrels, victims of road traffic. isolates were identified using restriction fragment length polymorphism (rflp): b. burgdorferi sensu stricto was present in 14 culture tubes containing skin samples and b. afzelii in two other tubes. a mixed infection was revealed in one case. a tota ... | 1998 | 9638274 |
| expression of outer surface proteins a and c of borrelia afzelii in ixodes ricinus ticks and in the skin of mice. | several studies have described changes in the expression of proteins, especially of ospa and ospc, of b. burgdorferi sensu stricto during tick feeding. in this study, the expression of ospa and ospc of b. afzelii in unfed and feeding i. ricinus nymphs and in the subsequent adults was followed by means of the immunofluorescence test. spirochaetes expressing ospa and ospc were observed in 70% and 80%, respectively of the unfed nymphs. in feeding and in fully engorged ticks, spirochaetes expressed ... | 1998 | 9638876 |
| lyme disease borrelia species in northeastern china resemble those isolated from far eastern russia and japan. | fifty-nine borrelia burgdorferi sensu lato culture isolates collected from northeastern china were characterized by 5s-23s rrna intergenic spacer restriction fragment length polymorphism (rflp) analysis and reactivity with monoclonal antibodies (mabs). among 59 culture isolates, 30 (50.8%) were borrelia garinii and 17 (28.8%) were borrelia afzelii, 2 were mixtures composed of b. garinii with rflp pattern b and b. garinii with pattern c, and 9 were mixtures composed of b. garinii and b. afzelii. ... | 1998 | 9647853 |
| experimental transmission of ehrlichia equi to horses through naturally infected ticks (ixodes pacificus) from northern california. | we report the experimental transmission of ehrlichia equi from naturally infected ixodes pacificus ticks to horses. three weeks after exposure to ticks, two of three horses developed clinical signs compatible with e. equi infection, while one horse remained asymptomatic. 16s rrna gene pcr of blood leukocyte lysates was positive for all horses at various time points; two horses seroconverted. the 16s rrna gene sequences amplified from tick-exposed horses showed more than 99% homology to correspon ... | 1998 | 9650983 |
| interstadial and infestation level-dependent variation in the transmission efficiency of borrelia burgdorferi from mice to ixodes ricinus ticks. | the efficiency with which the spirochaete borrelia burgdorferi sensu stricto was transmitted from laboratory mice to larval and nymphal ixodes ricinus ticks was assessed, using the polymerase chain reaction. the transmission efficiency to nymphs was significantly greater than to larvae when both fed together on the same host. increased tick infestation levels of mice were correlated with significantly greater engorgement weights and higher b. burgdorferi transmission coefficients from mice to ny ... | 1998 | 9652097 |
| in vitro susceptibilities of 27 rickettsiae to 13 antimicrobials. | the mics of 13 antibiotics (doxycycline, thiamphenicol, rifampin, amoxicillin, gentamicin, co-trimoxazole, ciprofloxacin, pefloxacin, ofloxacin, erythromycin, josamycin, clarithromycin, and pristinamycin) were determined for 27 available rickettsial species or strains. we used two in vitro cell culture methods described previously: the plaque assay and the microplaque colorimetric assay. our results confirm the susceptibilities of rickettsiae to doxycycline, thiamphenicol, and fluoroquinolones. ... | 1998 | 9660979 |
| [erve and eyach: two viruses isolated in france, neuropathogenic for man and widely distributed in western europe]. | two arboviruses have been isolated from mayenne, western france, in 1981-1982, during systematic field surveys: eyach virus, a cultivirus from ixodes ricinus and i. ventalloi ticks, and erve virus, a nairovirus from the tissues of white-toothed shrews, crocidura russula. for many years, these two viruses were considered as "orphan viruses" without pathogenic power for man, since it became evident that they circulate actively in europe among populations of wild small and large mammals. moreover, ... | 1998 | 9673063 |
| borrelia burgdorferi s.l. and ehrlichia chaffeensis in the national park of abruzzo. | the aims of the present study were (a) to determine the presence of ixodes ricinus in three different areas of the national park of abruzzo; (b) to search for the presence of borrelia burgdorferi in the collected sample of ixodes; (c) to determine the seroprevalence of b. burgdorferi antibodies and e. chaffeensis antibodies in inhabitants of the park and in park workers. the presence of b. burgdorferi in ixodes was checked by pcr. for the detection of antibodies to b. burgdorferi all sera were a ... | 1998 | 9675844 |
| predictive map of ixodes ricinus high-incidence habitats and a tick-borne encephalitis risk assessment using satellite data. | the main objective of this project was to predict ixodes ricinus abundant habitats reliably as a means of tick-borne encephalitis (tbe) risk assessment for the prevention of this disease. the vegetation types were used as the indicators of an ecosystem suitable for tick occurrence, for tbe virus circulation and, accordingly, for the existence of natural foci of this infection. remote sensing methods were used to determine the indicative plant cover. satellite data covering an experimental area o ... | 1998 | 9680691 |
| failure of ixodes ticks to inherit borrelia afzelii infection. | to define conditions promoting inherited infection by lyme disease spirochetes in ixodes ticks, we variously infected ticks with borrelia afzelii and examined their progenies by dark-field microscopy, immunofluorescence, pcr, and serial passage. no episode of inherited infection was evident, regardless of instar or gender infected or frequency of exposure. we suggest that these spirochetes rarely, if ever, are inherited by vector ticks. | 1998 | 9687480 |
| vector competence of ixodes scapularis and ixodes ricinus (acari: ixodidae) for three genospecies of borrelia burgdorferi. | the vector competence of 2 tick species, ixodes ricinus (l.) and ixodes scapularis say, was determined and compared for 3 genospecies of borrelia burgdorferi. the 3 genospecies of b. burgdorferi used in the following experiments were borrelia burgdorferi sensu stricto (b-31 and b-31.d1 clone), borrelia afzelii (strain pgau. c3), and borrelia garinii (strain vs286 and vsbp). spirochetes from all 5 strains were inoculated intradermally into outbred mice; larval ticks of both species were subsequen ... | 1998 | 9701928 |
| increasing geographical distribution and density of ixodes ricinus (acari: ixodidae) in central and northern sweden. | the geographical distribution and density of ixodes ricinus (l.) in the 2 northern regions, svealand and norrland, in sweden were studied by using a questionnaire in swedish magazines for house owners and dog owners, and in provincial newspapers. analysis of the approximately 1,200 answers revealed that ticks are present in all parts of svealand (except northern värmland and northern and western dalarna), the southeastern part of norrland (i.e., gästrikland and hälsingland), and along the baltic ... | 1998 | 9701939 |
| diagnostic value of pcr for detection of borrelia burgdorferi in skin biopsy and urine samples from patients with skin borreliosis. | skin biopsies of 36 patients with erythema migrans and acrodermatitis chronica atrophicans (aca) before therapy and those of 8 patients after therapy were examined for borrelia burgdorferi dna by pcr. skin biopsies of 27 patients with dermatological diseases other than lyme borreliosis and those of 10 healthy persons were examined as controls. two different primer sets targeting 23s rrna (pcr i) and 66-kda protein (pcr ii) genes were used. pcr was performed with freshly frozen tissue (fft) and p ... | 1998 | 9705410 |
| detection of ehrlichia phagocytophila dna in ixodes ricinus ticks from areas in switzerland where tick-borne fever is endemic. | a total of 1,523 adult ixodes ricinus ticks were collected from regions where bovine ehrlichiosis is endemic and were examined for ehrlichia phagocytophila via pcr. of the ticks from cattle with ehrlichiosis, the ticks from healthy cattle, and the free-living ticks, 26.5% (18 of 68), 4.4% (35 of 802), and 0.8% (5 of 653), respectively, were positive. | 1998 | 9705425 |
| the dominant epitope of borrelia garinii outer surface protein c recognized by sera from patients with neuroborreliosis has a surface-exposed conserved structural motif. | epitope mapping of outer surface protein c (ospc) by using sera from patients with neuroborreliosis led to the identification of one single major immunodominant epitope within the c-terminal 10 amino acid residues. peptide binding studies and alanine replacement scanning of the c-terminal decapeptide, pvvaespkkp, revealed a critical role for the pkkp sequence and its terminal carboxyl group for the binding of immunoglobulin m (igm) antibodies from patients with lyme borreliosis. electron microsc ... | 1998 | 9712750 |
| identification of group vs116 strains among borrelia burgdorferi sensu lato grown from the hard tick, ixodes ricinus (linnaeus, 1758) by off-coupled restriction fragment length polymorphism analysis. | a total of 67 spirochetal isolates grown from the hard tick, ixodes ricinus were analysed by pcr amplification of the spacer region between two conserved structures, the 3' end of the 5s rrna and the 5' end of the 23s rrna genes of borrelia burgdorferi sensu lato. a 246-255 bp amplicon was generated from 13 reference strains of b. burgdorferi sensu lato representing the three major genospecies, b. burgdorferi sensu stricto, b. garinii, and b. afzelii, and from all 67 spirochetal isolates from ti ... | 1998 | 9728404 |
| human exposure to a granulocytic ehrlichia and other tick-borne agents in connecticut. | indirect fluorescent-antibody (ifa) staining methods with ehrlichia equi (mrk or bds strains) and western blot analyses containing a human granulocytic ehrlichiosis (hge) agent (nch-1 strain) were used to confirm probable human cases of infection in connecticut during 1995 and 1996. also included were other tests for ehrlichia chaffeensis, the agent of human monocytic ehrlichiosis (hme), babesia microti, and borrelia burgdorferi. thirty-three (8.8%) of 375 patients who had fever accompanied by m ... | 1998 | 9738027 |
| antigenic and genomic analysis of a borrelia burgdorferi sensu stricto strain isolated from ixodes ricinus ticks in alto adige-south tyrol, italy. | a borrelia burgdorferi sensu lato strain isolated from ixodes ricinus ticks in alto adige-south tyrol (northern italy) was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) of whole cell proteins, western immunoblotting analysis (wba) with polyclonal and monoclonal antibodies, and pulsed-field gel electrophoresis (pfge). the isolate named bz6 was identified as belonging to the genospecies b. burgdorferi sensu stricto on the basis of its protein profile and its reac ... | 1998 | 9744686 |
| genetic divergence and evolutionary instability in ospe-related members of the upstream homology box gene family in borrelia burgdorferi sensu lato complex isolates. | a series of related genes that are flanked at their 5' ends by a conserved upstream sequence element called the upstream homology box (uhb) have been identified in borrelia burgdorferi. these genes have been referred to as the uhb or erp gene family. we previously demonstrated that among a limited number of b. burgdorferi isolates, the uhb gene family is variable in composition and organization. prior to this report the uhb gene family in other species of the b. burgdorferi sensu lato complex ha ... | 1998 | 9746562 |
| transmission risk of borrelia burgdorferi sensu lato from ixodes ricinus ticks to humans in southwest germany. | the risk of borrelia burgdorferi infection and the value of antibiotic prophylaxis after tick bite are controversial. in this study, performed in two areas of southwestern germany, ticks were collected from 730 patients and examined by the polymerase chain reaction (pcr) for b. burgdorferi. to assess whether transmission of b. burgdorferi occurred, the patients were clinically and serologically examined after tick removal and during follow-up examinations. data from all tick bites gave a total t ... | 1998 | 9747761 |
| natural prevalence of infection with ehrlichia (cytoecetes) phagocytophila of ixodes ricinus ticks in scotland. | ixodes ricinus nymphs and adults were collected from vegetation and from sheep at four sites in scotland typical of areas endemic for tick-borne fever in sheep caused by infection with ehrlichia (cytoecetes) phagocytophila (rickettsiales). the great majority of ticks examined was from woodland sites adjacent to sheep farms where there was a high probability of them feeding on roe deer (capreolus capreolus) in a non-domestic focus of infestation and infection. ticks were examined for infection by ... | 1998 | 9760062 |
| genospecies identification and characterization of lyme disease spirochetes of genospecies borrelia burgdorferi sensu lato isolated from rodents in taiwan. | lyme disease spirochetes of the genospecies borrelia burgdorferi sensu lato were identified and characterized for the first time in taiwan. seven isolates, designated twkm1 to twkm7, were purified from the ear tissues of three species of rodents captured from seven localities of taiwan. the immunological characteristics of these taiwan isolates were compared with those of other genospecies of lyme disease spirochetes by analyzing the protein profiles and reactivities with b. burgdorferi-specific ... | 1998 | 9774551 |
| detection of active infection in nonhuman primates with lyme neuroborreliosis: comparison of pcr, culture, and a bioassay. | ideally a diagnosis of infection of the central nervous system (cns) is made by culture of the etiologic pathogen, but borrelia burgdorferi, the causative agent of lyme neuroborreliosis (lnb), is rarely cultured from the cerebrospinal fluid (csf). pcr and measurement of specific antibody in the csf also have their limitations. the role of available assays for lnb has not been studied carefully in a comparative investigation. there is a need to assess the reliability of assays and to increase the ... | 1998 | 9774573 |
| genetic heterogeneity of borrelia burgdorferi sensu lato in ixodes ricinus ticks collected in belgium. | borrelia burgdorferi sensu lato (s.l.), the etiological agent of lyme disease, is transmitted by the bite of ixodes ricinus. four hundred eighty-nine ticks, collected in four locations of a region of southern belgium where lyme disease is endemic, were examined for the presence of the spirochete. in a pcr test with primers that recognize a chromosomal gene of all strains, 23% of the ticks were found to be infected. the species b. burgdorferi s.l. comprises at least three pathogenic genomospecies ... | 1998 | 9774592 |
| detection and typing of borrelia burgdorferi sensu lato in ixodes ricinus ticks attached to human skin by pcr. | live ixodes ricinus ticks attached to humans residing in germany were examined for borreliae by dark-field microscopy and pcr. borrelia species were identified by 16s rrna sequence analysis, which showed the presence of several species, some not yet defined, and a high prevalence of multiply infected ticks. | 1998 | 9774593 |
| assessment of the risk of infestation of pastures by ixodes ricinus due to their phyto-ecological characteristics. | this study aims to assess the relationships between the phyto-ecological characteristics of grazing pastures and their risk of being infested by the hard tick ixodes ricinus. to that purpose, 128 pastures belonging to 20 dairy farms were observed from april to july 1994. the farms were located in western france. assessment of the tick population was made by four monthly, blanket-dragging sessions. the average infestation rate was 40.2%. six types of pastures were identified according to their ba ... | 1998 | 9779561 |
| differential expression of borrelia burgdorferi proteins during growth in vitro. | in an earlier paper we described the transcriptionally regulated differential levels of expression of two lipoproteins of borrelia burgdorferi, p35 and p7.5, during growth of the spirochetes in culture from logarithmic phase to stationary phase (k. j. indest, r. ramamoorthy, m. solé, r. d. gilmore, b. j. b. johnson, and m. t. philipp, infect. immun. 65:1165-1171, 1997). here we further assess this phenomenon by investigating whether the expression of other antigens of b. burgdorferi, including s ... | 1998 | 9784512 |
| molecular analysis of sequence heterogeneity among genes encoding decorin binding proteins a and b of borrelia burgdorferi sensu lato. | immunization of mice with borrelia burgdorferi decorin binding protein a (dbpa), one of two gene products of the dbpba locus, has been shown recently to confer protection against challenge. hyperimmune dbpa antiserum killed a large number of b. burgdorferi sensu lato isolates of diverse phylogeny and origin, suggesting conservation of the protective epitope(s). in order to evaluate the heterogeneity of dbpa and dbpb and to facilitate defining the conserved epitope(s) of these antigens, the seque ... | 1998 | 9784533 |
| dbpa, but not ospa, is expressed by borrelia burgdorferi during spirochetemia and is a target for protective antibodies. | dbpa is a target for antibodies that protect mice against infection by cultured borrelia burgdorferi. infected mice exhibit early and sustained humoral responses to dbpa and dbpb, suggesting that these proteins are expressed in vivo. many antigens expressed in mammals by b. burgdorferi are repressed in vitro at lower growth temperatures, and we have now extended these observations to include dbpa and dbpb. to confirm that the protective antigen dbpa is expressed in vivo and to address the questi ... | 1998 | 9784547 |
| [interspecies cross of ixodes ticks from the group ixodes ricinus-persulcatus]. | | 1998 | 9785023 |
| antigens of the sheep scab mite psoroptes ovis. | sheep scab caused by the mite psoroptes ovis (hering) is a highly contagious disease of sheep. as a first step in developing a mite-derived vaccine for controlling the disease, the soluble antigens in mite extracts which induce an immune response in sheep were identified by electrophoretic and immunoblotting techniques. at least 22 proteins were present in p. ovis extracts as revealed by coomassie blue staining. mite-infested sheep serum recognised six antigenic bands in the extracts with approx ... | 1998 | 9805786 |
| interaction of virulent and attenuated tick-borne encephalitis virus strains in ticks and a tick cell line. | an interference between a thermosensitive (ts) mutant and the wild-type (wt) of tick-borne encephalitis (tbe) virus in ixodes ricinus l. and rhipicephalus appendiculatus (neumann) ticks is reported. i. ricinus females were dually infected by a parenteral inoculation of ts and wt strains at 10-day interval. interference was demonstrated by the lowered ability of wt virus to replicate in ticks previously infected by ts virus. the wt virus was demonstrated in only 30% of the ticks; the average viru ... | 1998 | 9805787 |
| identification of four borrelia burgdorferi sensu lato species in ixodes ricinus ticks collected from dutch dogs. | the prevalence of borrelia species infection was determined by polymerase chain reaction (pcr) in 138 ticks collected from dogs which were walked regularly in the wooded areas near the city of eindhoven, the netherlands. the pcr amplified the spacer region between the 5s and 23 s rrna genes, and the borrelia species was identified by hybridization with specific probes. borrelia burgdorferi sensu lato was present in 20 of 138 (14.5%) ticks. four species were identified: b. burgdorferi sensu stric ... | 1998 | 9810630 |
| lyme disease in italy, 1983-1996. | this paper is a brief review of the epidemiology of lyme disease in italy. the first case of the illness was identified by crovato in liguria in 1983. in the following years, many other cases have been reported from all italian regions with the exception of valle d'aosta, basilicata and calabria. the exact number of cases in our country is not known because lyme disease was not a notifiable disease until 1990, but on the basis of literature data, at least 1324 cases have been observed in the fou ... | 1998 | 9812324 |
| development of a natural model of cutaneous leishmaniasis: powerful effects of vector saliva and saliva preexposure on the long-term outcome of leishmania major infection in the mouse ear dermis. | we have developed a model of cutaneous leishmaniasis due to leishmania major that seeks to mimic the natural conditions of infection. 1,000 metacyclic promastigotes were coinoculated with a salivary gland sonicate (sgs) obtained from a natural vector, phlebotomus papatasii, into the ear dermis of naive mice or of mice preexposed to sgs. the studies reveal a dramatic exacerbating effect of sgs on lesion development in the dermal site, and a complete abrogation of this effect in mice preexposed to ... | 1998 | 9815271 |
| seroprevalence of ehrlichia canis and of canine granulocytic ehrlichia infection in dogs in switzerland. | serum samples from 996 dogs in switzerland were examined for antibodies to ehrlichia canis and to the agent causing canine granulocytic ehrlichiosis (cge). ehrlichiosis, borreliosis, and systemic illness not associated with ticks were suspected in 75, 122, and 157 of these dogs, respectively. the remainder of the serum samples were obtained from clinically healthy dogs which resided north (n = 235) or south (n = 407) of the alps. the serum samples were tested by an indirect immunofluorescence te ... | 1998 | 9817854 |
| acquisition and transmission of the agent of human granulocytic ehrlichiosis by ixodes scapularis ticks. | the purpose of the present study was to investigate the transmission of a human isolate of the agent of human granulocytic ehrlichiosis (hge agent) from infected mice to larval ticks and to examine the population kinetics of the hge agent in different stages of the tick life cycle. the hge agent was quantitated by competitive pcr with blood from infected mice and with ixodes scapularis ticks. the median infectious dose for c3h mice was 10(4) to 10(5) organisms when blood from an infected severe ... | 1998 | 9817875 |
| granulocytic ehrlichia infection in ixodid ticks and mammals in woodlands and uplands of the u.k. | the prevalence of infection with ehrlichiae of the ehrlichia phagocytophila genogroup (the granulocytic ehrlichiae), in questing ixodes ricinus ticks of u.k. upland and woodland habitats, was investigated by pcr. the prevalence of infection in the three feeding stages of i. ricinus indicated that granulocytic ehrlichiae are transmitted transstadially with no, or inefficient, transovarial transmission. the presence of infected ticks in both habitats indicates that endemic cycles of granulocytic e ... | 1998 | 9824827 |
| persistence of anaplasma ovis infection and conservation of the msp-2 and msp-3 multigene families within the genus anaplasma. | goats which have recovered from acute anaplasma ovis infection remain seropositive, although infected erythrocytes cannot be detected by microscopic examination. persistence of a. ovis 17 to 21 months following experimental infection was demonstrated by pcr detection of the msp-5 gene. quantitative analysis of persistent rickettsemia over time showed that all levels were below the limit of microscopic detection and ranged from a low of 10(2) organisms/ml to peaks of 10(6) organisms/ml. two patte ... | 1998 | 9826393 |
| expression of outer surface proteins a and c of borrelia burgdorferi in ixodes ricinus ticks removed from humans. | a total of 131 ixodes ricinus (51 females, 1 male and 79 nymphs) removed from persons living in southern germany were investigated by immunofluorescence assay for the presence of borrelia burgdorferi with a polyvalent rabbit immune serum and monoclonal antibodies specific for outer surface proteins (osp) a or c. borreliae were detectable in 48 (36.6%) of the ticks. infection rates of these adults and nymphs were significantly higher than infection rates of unfed ticks from southern germany. borr ... | 1998 | 9832327 |
| identity of ehrlichial dna sequences derived from ixodes ricinus ticks with those obtained from patients with human granulocytic ehrlichiosis in slovenia. | adult ixodes ricinus (acari: ixodidae) ticks collected near ljubljana, slovenia, were tested for the agent of human granulocytic ehrlichiosis (hge) by using pcr assays based on the 16s rrna gene. three (3.2%) of 93 ticks were found to contain granulocytic ehrlichiae. nucleotide sequences of portions of the bacterial groesl heat shock operon amplified from these ticks were identical or nearly (99.8%) identical to those previously determined for human patients with hge from slovenia, providing add ... | 1999 | 9854093 |
| borrelia-infection rates in tick and insect vectors accompanying human risk of acquiring lyme borreliosis in a highly endemic region in central europe. | the methods of spatial statistics were applied to assess the geographical pattern of risk of lyme borreliosis in central bohemia, the czech republic, based on retrospective data on disease contractions. the statistical risk was then compared at 15 selected localities with the infection challenge presented by ticks and insects carrying borreliae. over 5,000 ixodes ricinus (l.) ticks and 390 haematophagous dipterans were screened by direct immunofluorescence method, and the spatial and seasonal va ... | 1998 | 9868793 |
| rickettsia helvetica in ixodes ricinus ticks in sweden. | in the present study further characterization of the amplified sequence of the citrate synthase gene of the spotted fever group rickettsia isolated from ixodes ricinus ticks in sweden showed that it has 100% homology with the deposited sequence of the citrate synthase gene of rickettsia helvetica. the restriction fragment length polymorphism (rflp) pattern of an amplified 382-bp product of the citrate synthase sequence, defined by primers rpcs877 and rpcs1258, yielded fragments for our isolate t ... | 1999 | 9889227 |
| [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 ... | 1998 | 9921400 |
| characteristics of garden dormice that contribute to their capacity as reservoirs for lyme disease spirochetes. | to describe the contribution of garden dormice to the epizootiology of lyme disease, we compared their reservoir capacity for these pathogens to that of other sympatric hosts. garden dormice are trapped most abundantly during early spring and again during midsummer, when their offspring forage. they are closely associated with moist forests. garden dormice serve as hosts to nymphal ticks far more frequently than do other small mammals. spirochetal infection is most prevalent in dormice, and many ... | 1999 | 9925604 |
| [the epidemiology of lyme borreliosis]. | lyme borreliosis (lb) is a multisystem disease caused by infection with borrelia burgdorferi sensu lato (b.b). lb is the most common human tick-borne disease, transmitted principally by species of ixodes ricinus in europe, i. persulcatus in eurasia, i. scapularis and i. pacificus in north america. b.b has been isolated or detected in 24 different species of mammals or birds. the b31 strain of b.burgdorferi sensu stricto is predominant in united states and in europe b. garinii, b. afzelii and b. ... | 1998 | 9932000 |
| genetic diversity of borrelia burgdorferi in lyme disease patients as determined by culture versus direct pcr with clinical specimens. | two hundred seventeen isolates of borrelia burgdorferi originally cultured from skin biopsy samples or blood of early lyme disease patients were genetically characterized by pcr-restriction fragment length polymorphism (rflp) typing of the 16s-23s ribosomal dna intergenic spacer. three major rflp types were observed. of the cultured isolates, 63 of 217 (29.0%) were type 1, 85 of 217 (39.2%) were type 2, and 58 of 217 (26.7%) were type 3; mixtures of two rflp types were obtained in 6.0% (13 of 21 ... | 1999 | 9986813 |
| body lice as tools for diagnosis and surveillance of reemerging diseases. | body lice are vectors of three bacteria which cause human disease: rickettsia prowazekii, the agent of epidemic typhus; bartonella quintana, the agent of trench fever; and borrelia recurrentis, the agent of relapsing fever. a recrudescence of body lice is being observed as the numbers of individuals living under social conditions which predispose individuals to infestation have increased. because this phenomenon may lead to the reemergence of infections transmitted by body lice, we aimed to asse ... | 1999 | 9986818 |
| prevalence of borrelia burgdorferi s.i. in ixodes ricinus ticks from styria (austria) and species identification by pcr-rflp analysis. | a total of 1163 i. ricinus ticks were collected in 3 different regions (15 localities) in styria (austria) in june 1997 and examined for the presence of spirochetes by dark field microscopy. the mean infection rate was 20.8%. among 310 adults, 24.2% were positive and among 853 nymphs, 19.6% were positive. all 15 collection areas were shown to harbour infected nymphs with a positivity rate ranging from 5.8% (3/52) to 32.1% (18/56). isolation attempts in bskii medium resulted in 29 isolates. speci ... | 1998 | 9987185 |
| a serological study of cohorts of young dogs, naturally exposed to ixodes ricinus ticks, indicates seasonal reinfection by borrelia burgdorferi sensu lato. | thirty-three family dogs were monitored for antibodies to borrelia burgdorferi sensu lato over a 3-year period. serum samples were collected before and during the season of high tick activity. antibody levels were measured with an elisa based on whole-cell antigens and an elisa with a purified recombinant flagellin (r410). antibody levels measured with the whole-cell elisa increased after the first exposure to ticks. following the first seasonal period of tick quiescence, antibody levels decreas ... | 1999 | 9990702 |
| incidence from coincidence: patterns of tick infestations on rodents facilitate transmission of tick-borne encephalitis virus. | tick-borne encephalitis (tbe) virus has a highly focal distribution through eurasia. endemic cycles appear to depend on the transmission of non-systemic infections between ticks co-feeding on the same rodent hosts. the particular features of seasonal dynamics and infestation patterns of larval and nymphal ixodes ricinus, but not dermacentor reticulatus, from 4 regions within tbe foci in slovakia, are such as to promote tbe virus transmission. the distributions of larvae and nymphs on their princ ... | 1999 | 10028532 |
| detection of the agent of human granulocytic ehrlichiosis (hge) in uk ticks using polymerase chain reaction. | nymphal ixodes ricinus ticks collected from woodland areas in south wales, uk, were tested using the polymerase chain reaction for the presence both of the causative agent of human granulocytic ehrlichiosis (hge) and borrelia burgdorferi. twenty-two of 60 (37%) ticks were found positive in the pcr for b. burgdorferi and 4/60 (7%) for the hge agent. one tick was found positive both for b. burgdorferi and hge agent. our findings imply the presence of the hge agent in uk ticks and the finding of a ... | 1998 | 10030718 |
| detection of hge agent-like ehrlichia in ixodes ricinus ticks in northern italy by pcr. | little is known about the distribution of human granulocytic ehrlichiosis (hge) in europe and even less is known in italy, where no case of clinically documented hge has been reported. in a previous study we reported the presence of ehrlichia dna in ixodes ricinus ticks from central italy. by the use of an ehrlichia-specific pcr we found that 24% of the ticks were positive. furthermore, we demonstrated a simultaneous coinfection of the same tick by both, borrelia burgdorferi and ehrlichia phagoc ... | 1998 | 10048173 |
| [the genotyping of strains of borrelia burgdorferi sensu lato isolated in byelarus from ixodes ricinus ticks]. | | 1998 | 10050547 |
| transmission of borrelia afzelii from apodemus mice and clethrionomys voles to ixodes ricinus ticks: differential transmission pattern and overwintering maintenance. | this study deals with the ecology of lyme borreliosis in europe. the relationships between borrelia burgdorferi sensu lato spirochetes, clethrionomys and apodemus rodent reservoirs and the ixodes ricinus tick vector were investigated during 16 consecutive months in an enzootic area in switzerland. cultivation of ear skin biopsies was used to isolate spirochetes from c. glareolus, a. sylvaticus, a. flavicollis and glis glis. borrelia infection was more frequently observed in clethrionomys than in ... | 1999 | 10070659 |
| isolation of lyme disease borrelia from puffins (fratercula arctica) and seabird ticks (ixodes uriae) on the faeroe islands. | this is the first report on the isolation of lyme disease borrelia from seabirds on the faeroe islands and the characteristics of its enzootic cycle. the major components of the borrelia cycle include the puffin (fratercula arctica) as the reservoir and ixodes uriae as the vector. the importance of this cycle and its impact on the spread of human lyme borreliosis have not yet been established. borrelia spirochetes isolated from 2 of 102 sampled puffins were compared to the borreliae previously o ... | 1999 | 10074497 |
| serological evidence of infection with ehrlichia spp. in red foxes (vulpes vulpes) in switzerland. | serum samples from 1,550 red foxes in switzerland were tested for antibodies to the agents of canine granulocytic and monocytic ehrlichiosis by an indirect immunofluorescent technique. forty-four (2.8%) of the samples were positive for ehrlichia phagocytophila, which is an antigen marker for granulocytic ehrlichiosis. in contrast, none of the samples had antibodies specific to ehrlichia canis, the agent of monocytic ehrlichiosis. | 1999 | 10074544 |
| infection of ixodes ricinus (acari: ixodidae) by borrelia burgdorferi sensu lato in north africa. | free-living adult ixodes ricinus l, were collected in amdoun, situated in the kroumiry mountains in northwestern tunisia (north africa). using direct fluorescence antibody assay, the infection rate of field-collected i. ricinus by borrelia burgdorferi sensu lato was 30.5% (n = 72). no difference in infection rate was observed between male and female ticks. spirochetes that had been isolated from i. ricinus from ain drahim (kroumiry mountains) in 1988 were identified as borrelia lusitaniae (forme ... | 1999 | 10083761 |
| tick-borne encephalitis and lyme borreliosis: comparison of habitat risk assessments using satellite data (an experience from the central bohemian region of the czech republic). | the vegetation types have been used as the indicators of an ecosystem suitable for high incidence of ixodes ricinus ticks and their hosts, for the circulation of tick-borne diseases pathogens and, accordingly, for the existence of natural foci of these infections, namely tick-borne encephalitis (tbe) and lyme borreliosis (lb). the method of remote sensing offers a suitable solution to this problem. we attempted to prepare the habitat risk assessment maps on the territory (11,500 km2) of central ... | 1999 | 10084020 |
| incidence of spirochetes (borrelia sp.) in the tick ixodes ricinus in the urban environment (capital of prague) between 1994-1997. | a total of 12287 ticks were collected from 10 localities of the capital of prague between 1994 and 1997 (2978 ticks in 1994, 5612 ticks in 1995-1996, 3686 ticks in 1997). the presence of borrelia was investigated by the indirect immunofluorescence assay using hyperimmune rabbit sera. the tick infestation ranged between 3.8% and 9.7% (1994), 7.9% and 11.3% (1995), 3.6% and 6.2% (1996) and 4.8% and 9.2% (1997). the results obtained are indicative of a relatively high opportunity for exposure to th ... | 1999 | 10096169 |
| quantitative real-time pcr for detection of members of the ehrlichia phagocytophila genogroup in host animals and ixodes ricinus ticks. | a taqman pcr was established for identification and quantitation of members of the ehrlichia phagocytophila group in experimentally infected cows and in ixodes ricinus ticks. the taqman pcr identified a 106-bp section of the 16s rrna gene by use of a specific fluorogenic probe and two primers. this technique was specific for members of the e. phagocytophila group, which include e. phagocytophila, ehrlichia equi, and the agent of human granulocytic ehrlichiosis. the taqman system identified 10 co ... | 1999 | 10203480 |
| evidence of the human granulocytic ehrlichiosis agent in ixodes ricinus ticks in switzerland. | a total of 1,667 ixodes ricinus ticks were collected from five regions in switzerland where there have been sporadic occurrences of granulocytic ehrlichiosis in dogs and horses. the ticks were examined for rickettsiae of the ehrlichia phagocytophila group via nested pcr. twenty-one ticks (1.3%) were positive; 3 (0.5%) were nymphs, 6 (1.3%) were adult males, and 12 (1.9%) were adult females. the number of positive ticks varied with the stage of development and with the geographical origin. nucleo ... | 1999 | 10203481 |
| prevalence of borrelia burgdorferi in ixodes ricinus ticks in urban recreational areas of helsinki. | lyme borreliosis, an infection caused by the tick-borne spirochete borrelia burgdorferi, is a major health problem for populations in areas of endemicity in the northern hemisphere. in the present study we assessed the density of ticks and the prevalence of b. burgdorferi sensu lato among ticks in popular urban recreational areas of helsinki, finland. altogether 1,688 ixodes ricinus ticks were collected from five areas located within 5 km of the downtown section of helsinki, and 726 of them (303 ... | 1999 | 10203487 |
| the effects of ehrlichia (cytoecetes) phagocytophila on the clinical chemistry of sheep and goats. | tick-borne fever (tbf) is a rickettsial disease of domestic and wild ruminants in temperate climates where the hard tick ixodes ricinus is present. the disease is characterized by a high temperature and severe leukopenia. in the present study, the effects of tbf on the activity of serum alkaline phosphatase (alp), and on the concentrations of plasma zinc, iron, total bilirubin, urea, creatinine and albumin were investigated by inoculating one group of eight sheep and one group of eight goats wit ... | 1999 | 10216452 |
| successive tick infestations selectively promote a t-helper 2 cytokine profile in mice. | several studies have revealed that t lymphocytes and cytokines play a crucial role in determining the outcome of parasitic infections in terms of protective immunity. in this study we found that rhipicephalus sanguineus tick saliva stimulates transforming growth factor-beta (tgf-beta), and reduces interleukin-12 (il-12) secretion by cells from normal c3h/hej mice. moreover, murine lymph node cells harvested 6 days after the fourth infestation with ticks presented an 82.4% decrease in their proli ... | 1999 | 10233725 |
| simultaneous detection of bovine theileria and babesia species by reverse line blot hybridization. | a reverse line blot (rlb) assay was developed for the identification of cattle carrying different species of theileria and babesia simultaneously. we included theileria annulata, t. parva, t. mutans, t. taurotragi, and t. velifera in the assay, as well as parasites belonging to the t. sergenti-t. buffeli-t. orientalis group. the babesia species included were babesia bovis, b. bigemina, and b. divergens. the assay employs one set of primers for specific amplification of the rrna gene v4 hypervari ... | 1999 | 10325324 |
| southern extension of the range of human babesiosis in the eastern united states. | we sought evidence of babesiosis in three residents of new jersey who were suspected of local acquisition of babesia microti infection. we tested serial blood samples from these residents for b. microti antibodies and amplifiable dna by using immunofluorescent antibody and pcr techniques. all three residents experienced symptoms suggestive of acute babesiosis. the sera of each of the patients reacted against babesial antigen at a titer fourfold or higher in sequentially collected blood samples. ... | 1999 | 10325378 |
| [borrelia species new to russia--possible causative agents of ixodid tick-borne borreliosis]. | 18 borrelia isolates, obtained in 1996-1997 from adult ixodes ricinus collected from plants in the environs of stavropol', were identified with the use of the polymerase chain reaction and the analysis of the polymorphism of the length of restriction fragments. among them, in addition to b. garinii and b. afzelii, widely spread in eurasia, 2 recently described species, b. valaisiana and b. lusitaniae, were found in russia for the first time. their possible spread and their importance in infectio ... | 1999 | 10356723 |
| density of deer in relation to the prevalence of borrelia burgdorferi s.l. in ixodes ricinus nymphs in rambouillet forest, france. | the rambouillet forest, a lyme disease-endemic area near paris, france, was surveyed from september 1994 to october 1995 to determine the risk periods and zones for humans. firstly, during the period of ixodes ricinus activity, abundance of nymphs is greater in spring than in autumn. secondly, we observed significant variation in nymphal abundance between zones according to the density of cervids. the polymerase chain reaction (pcr) was used to detect dna of borrelia burgdorferi sensu lato in 46 ... | 1999 | 10356769 |
| borrelia burgdorferi in tick cell culture modulates expression of outer surface proteins a and c in response to temperature. | the lyme disease spirochete borrelia burgdorferi sensu stricto downregulates outer surface protein a (ospa) and upregulates outer surface protein c (ospc) during tick feeding. the switching of these proteins correlates with increased spirochetal infectivity for the mammal. we examined the effect of temperature on differential expression of ospa and ospc by b. burgdorferi cocultivated with a cell line isolated from the vector tick ixodes scapularis. the effect of incubation at 31, 34, or 37 degre ... | 1999 | 10364575 |
| detection and identification of ehrlichia, borrelia burgdorferi sensu lato, and bartonella species in dutch ixodes ricinus ticks. | a sensitive and specific pcr hybridization assay was developed for the simultaneous detection and identification of ehrlichia and borrelia burgdorferi sensu lato. in separate assays the 16s rrna gene of ehrlichia species and the 23s-5s rrna spacer region of b. burgdorferi sensu lato were amplified and labeled by pcr. these pcr products were used in a reverse line blot hybridization assay in which oligonucleotide probes are covalently linked to a membrane in parallel lines. hybridization of the s ... | 1999 | 10364588 |
| bacterioferritin a modulates catalase a (kata) activity and resistance to hydrogen peroxide in pseudomonas aeruginosa. | we have cloned a 3.6-kb genomic dna fragment from pseudomonas aeruginosa harboring the rpoa, rplq, kata, and bfra genes. these loci are predicted to encode, respectively, (i) the alpha subunit of rna polymerase; (ii) the l17 ribosomal protein; (iii) the major catalase, kata; and (iv) one of two iron storage proteins called bacterioferritin a (bfra; cytochrome b1 or b557). our goal was to determine the contributions of kata and bfra to the resistance of p. aeruginosa to hydrogen peroxide (h2o2). ... | 1999 | 10368148 |
| climate change and human health in europe. | | 1999 | 10373176 |
| effects of environmental ph on membrane proteins in borrelia burgdorferi. | borrelia burgdorferi, the causative agent of lyme disease, alternates between the microenvironments of the tick vector, ixodes scapularis, and a mammalian host. the environmental conditions the spirochete encounters during its infectious cycle are suspected to differ greatly in many aspects, including available nutrients, temperature, and ph. here we identify alterations in the membrane protein profile, as determined by immunoblotting and two-dimensional nonequilibrium ph gradient gel electropho ... | 1999 | 10377088 |
| ixodid ticks avoid contact with liquid water. | larvae of the cattle tick boophilus microplus and all life stages of the european sheep tick ixodes ricinus avoid walking on a wet membrane surface surrounding a dry patch. of 170 reactions made at a border with liquid water by 22 b. microplus larvae, 40% consisted of immediate turns to the opposite side to bring all the legs back onto a dry patch, 41% were walks along the border, during which the ticks maintained contact with both the dry and wet zones, and 19% were returns to the dry patch aft ... | 1999 | 10377269 |
| influence of the genetic background and parasite load of mice on the immune response developed against nymphs of ixodes ricinus. | the immune response of balb/c (h-2d), dba (h-2d), c57bl/6 (h-2b), c3h (h-2k), cba (h-2k), sjl (h-2s), and fvb (h-2q) mice infested once with 15 nymphs of ixodes ricinus is polarized toward th2 as suggested by cytokines produced by lymph node cells stimulated with concanavalin a. the parasite load does not influence the polarization of the immune response as observed in balb/c mice, which developed a th2 response when infested with 5 or 45 nymphs. as assessed by attachment and weights of engorged ... | 1999 | 10382605 |
| in vitro activities of the everninomicin sch 27899 and other newer antimicrobial agents against borrelia burgdorferi. | the in vitro activity of the everninomicin antibiotic sch 27899 against 17 isolates of borrelia spp. was investigated. mics ranged from 0.06 to 0.5 microg/ml. time-kill studies with the b31 strain of b. burgdorferi demonstrated >/=3-log10-unit killing after 72 h with concentrations representing four times the mic. the in vitro activity of four other newer antimicrobial agents, meropenem, cefepime, quinupristin-dalfopristin, and linezolid, was also tested against the b31 strain. meropenem was the ... | 1999 | 10390242 |
| mosaic pattern of borrelia infection in a continuous population of the tick ixodes ricinus (acari: ixodidae). | an array of 12 20 x 20 m quadrats in a mixed forest near poteply, central bohemia, czech republic, was investigated for the abundance and spatial distribution of host-questing ixodes ricinus nymphs and their infection with borreliae. tick densities were estimated by flagging and their borrelia infection status was determined by direct immunofluorescence. while the tick population appeared to be continuous and homogeneous based on quadrat counts, their infection with borreliae evinced a mosaic pa ... | 1999 | 10399308 |
| invasion and intracellular development of the human granulocytic ehrlichiosis agent in tick cell culture. | human granulocytotropic ehrlichias are tick-borne bacterial pathogens that cause an acute, life-threatening illness, human granulocytic ehrlichiosis (hge). ehrlichias within neutrophil granulocytes that invade tick bite sites are likely ingested by the vector, to be transmitted to another mammalian host during the tick's next blood meal. thus, the cycle of replication and development in the vector is prerequisite to mammalian infection, and yet these events have not been described. we report tic ... | 1999 | 10405394 |