Publications

genomic comparison of rickettsia helvetica and other rickettsia species.	we report the complete and annotated genome sequence of rickettsia helvetica strain c9p9, which was first isolated in 1979 from ixodes ricinus ticks in switzerland and is considered a human pathogen.	0	22535934
confirmation that rickettsia helvetica sp. nov. is a distinct species of the spotted fever group of rickettsiae.	we propose the name rickettsia helvetica sp. nov. for a rickettsial serotype of unknown pathogenicity isolated in 1979 in switzerland from ixodes ricinus ticks and designated the swiss agent. the growth characteristics and the results of microimmunofluorescence serologic typing, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, western blotting (immunoblotting) with specific mice sera, and a polymerase chain reaction followed by restriction fragment length polymorphism analysis confirme ...	1993	8102245
characterization of a spotted fever group rickettsia from ixodes ricinus ticks in sweden.	a spotted fever group rickettsia isolated from the common tick, ixodes ricinus, was genetically characterized by pcr and genomic sequencing. this study was performed with nymphal and adult ticks collected in southern and central sweden. i. ricinus is the only north european tick species of medical importance which is regularly collected from humans. no species of the genus rickettsia has previously been found in scandinavian ticks, nor has any case of domestic rickettsial infection in humans or ...	1997	8968916
citrate synthase gene comparison, a new tool for phylogenetic analysis, and its application for the rickettsiae.	using pcr and an automated laser fluorescent dna sequencer, we amplified and sequenced a 1,234-bp fragment of the citrate synthase-encoding gene (glta) of 28 bacteria belonging to the genus rickettsia. comparative sequence analysis showed that most of the spotted fever group (sfg) rickettsiae belonged to one of two subgroups. the first subgroup included rickettsia massiliae, strain bar 29, rickettsia rhipicephali, "rickettsia aeschlimanni," and rickettsia montana, which have been isolated only f ...	1997	9103608
distribution of immunogenic epitopes on the two major immunodominant proteins (rompa and rompb) of rickettsia conorii among the other rickettsiae of the spotted fever group.	forty-four monoclonal antibodies were raised against strain seven, the type strain of rickettsia conorii. of these 44 monoclonal antibodies, 13, 27, and 4 were demonstrated to be directed against the 116-kda protein (rompa), the 124-kda protein (rompb), and lipopolysaccharide-like antigen, respectively. the antiprotein monoclonal antibodies were found to be directed against 29 distinct epitopes, which were located on the two major immunodominant proteins discussed above. further analysis showed ...	1997	9384303
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
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
association of rickettsia helvetica with chronic perimyocarditis in sudden cardiac death.	rickettsia helvetica is the only non-imported rickettsia found in scandinavia. it was first detected in ixodes ricinus ticks, but has never been linked to human disease. we studied two young swedish men who died of sudden cardiac failure during exercise, and who showed signs of perimyocarditis similar to those described in rickettsial disease.	1999	10513711
evidence of rickettsia helvetica infection in humans, eastern france.	a 37-year-old man living in eastern france seroconverted to rickettsia helvetica in august 1997, 4 weeks after the onset of an unexplained febrile illness. results of a serosurvey of forest workers from the area where the patient lived showed a 9.2% seroprevalence against r. helvetica. this organism may pose a threat for populations exposed to ixodes ricinus ticks.	2000	10905974
[molecular tools in the epidemiology of tick-borne bacterial diseases].	molecular tools have been used to detect rickettsiae in ticks. in ixodes ricinus ticks collected in france, we detected for the first time there an emerging pathogen, rickettsia helvetica, and an ehrlichia sp, closely related to the agent of human granulocytic ehrlichiosis. in guadeloupe (french west indies), we described the occurrence of african tick-bite fever due to rickettsia africae, which had been previously reported in sub-saharan africa only. in africa, we completed our knowledge about ...	2001	11282521
phylogeny of rickettsia spp. inferred by comparing sequences of 'gene d', which encodes an intracytoplasmic protein.	'gene d' is the ps120-protein-encoding gene, first described in rickettsia conorii and rickettsia japonica. sequence analysis of a 3030 bp fragment of 'gene d' in 24 representatives of the genus rickettsia was carried out to complete phylogenetic analyses previously inferred by comparison of gene sequences encoding citrate synthase, 17 kda antigen and rompa and rompb. the phylogenetic relationships between rickettsiae were inferred from the comparison of both the gene and the derived protein seq ...	2001	11491333
presence of rickettsia helvetica in granulomatous tissue from patients with sarcoidosis.	in samples obtained during the autopsies of 2 patients with sarcoidosis, genetic material from rickettsia helvetica was detected by polymerase chain reaction, and histologic and immunohistochemical examination (using 3 different antibodies) of the polymerase chain reaction-positive tissues showed different degrees of granuloma formation and presence of rickettsia-like organisms predominantly located in the endothelium and macrophages. electron microscopic examination clearly identified and demon ...	2002	11930323
genetic identification of rickettsiae isolated from ticks in japan.	following the description in japan of japanese spotted fever, caused by rickettsia japonica, a search for the vector of this disease led to the isolation of several rickettsiae from various tick species. sixty-three rickettsial isolates were obtained from six different tick species, and six type strains were described by pcr and monoclonal antibody testing. we identified these six strains by amplification and sequencing of the genes encoding 16s rrna and citrate synthase. we confirmed that the i ...	2002	12037083
phylogenetic analysis of spotted fever group rickettsiae isolated from ticks in japan.	eight spotted fever group (sfg) rickettsiae isolated from ticks in japan were classified by phylogenetic analysis based on the nucleotide sequences of both the citrate synthase-encoding gene (glta) and 190-kda antigen-encoding gene (rompa). in the phylogenetic tree of glta, strains dt-1 and fla-1 isolated from the dermacentor taiwanensis and haemaphysalis frava ticks, respectively, were placed as rickettsia japonica, and strains io-1, io-2, io-25, im-1 and ip-2 from genus ixodes ticks were place ...	2002	12061626
first detection of spotted fever group rickettsiae in ixodes ricinus from italy.	ixodes ricinus from italy were examined for the first time to detect whether rickettsiae were present. using molecular methods, we detected three different spotted fever group rickettsiae, including rickettsia helvetica. our results raise the possibility that bacteria other than r. conorii are involved in rickettsial diseases in italy.	2002	12194779
tick paralysis by ixodes holocyclus in a japanese traveler returning from australia associated with rickettsia helvetica infection.		2003	12729517
[fever after a tick bite: clinical manifestations and diagnosis of acute tick bite-associated infections in northeastern switzerland].	different tick-borne infections can cause an acute febrile illness. the study objectives were to investigate the clinical manifestations and diagnosis of infections among patients who presented with fever after a tick-bite, and to detect newly described pathogens, including ehrlichia, babesia and rickettsia helvetica, in north-eastern switzerland.	2003	12736854
genetic diversity of bacterial agents detected in ticks removed from asymptomatic patients in northeastern italy.	a total of 360 ticks were removed from 353 asymptomatic subjects in belluno province, italy and surrounding areas, from 1998 to 2001. ticks were identified as ixodes ricinus (357), ixodes hexagonus (1), rhipicephalus sanguineus (1), and ixodes ventalloi (1). tick dna was investigated by pcr and subsequent sequencing of amplified products to identity associated bacterial agents. primers targeting different genes of rickettsia (glta and ompa), borrelia (16s rdna, rpob), francisella (16s rdna), and ...	2003	12860623
identification of borrelia burgdorferi sensu lato, anaplasma and ehrlichia species, and spotted fever group rickettsiae in ticks from southeastern europe.	prevalence data for tick-borne pathogens are used to assess the risk for human health. in this study the presence and identity of borrelia burgdorferi sensu lato, ehrlichia, anaplasma, and rickettsia species in bulgarian ixodes ricinus ticks and in non- ixodes ticks from turkey and albania was determined by polymerase chain reaction (pcr) and reverse line blot hybridization. in the adult bulgarian ticks, the prevalence of borrelia burgdorferi sensu lato infection was approximately 40%, while bor ...	2003	12938010
aneruptive fever associated with antibodies to rickettsia helvetica in europe and thailand.	we report that eight patients from france, italy, and thailand had serological evidence of rickettsia helvetica infection. the infection presented as a mild disease in the warm season and was associated with fever, headache, and myalgia but not with a cutaneous rash. r. helvetica should be suspected in patients with unexplained fever, especially following a bite from an ixodes sp. tick.	2004	14766859
pathogens and symbionts in ticks: prevalence of anaplasma phagocytophilum (ehrlichia sp.), wolbachia sp., rickettsia sp., and babesia sp. in southern germany.	tick-transmitted diseases like tick-borne encephalitis and lyme borreliosis have been well known in germany for decades. ongoing research now gives an additional focus to a broad range of other bacteria and parasites in ticks like anaplasma phagocytophilum, former ehrlichia sp., rickettsia sp. and babesia sp. knowledge about the prevalence of these infectious agents in ticks is an important prerequisite for risk assessment of human diseases. therefore nymphs and adult ixodes ricinus ticks were c ...	2004	15146989
detection and identification of rickettsia helvetica and rickettsia sp. irs3/irs4 in ixodes ricinus ticks found on humans in spain.		2004	15252721
ultrastructure of a japanese rickettsial strain genetically identified as rickettsia helvetica which was originally found in europe.	a rickettsial strain io-1 has been isolated from a tick, ixodes ovatus, in japan and genetically identified as rickettsia helvetica, a member of the spotted fever group rickettsiae. ultrastructural observations were made on the microorganism. the ultrastructure of r. helvetica io-1 appeared to be generally the same as that previously shown for other rickettsiae of the spotted fever and typhus groups. the rickettsiae were primarily found free in the cytoplasm of l929 cultured cells. occasionally, ...	2004	15272199
serological and molecular evidence of rickettsia helvetica in denmark.	recent seroepidemiological studies and examinations of ixodes ricinus ticks in europe have demonstrated the presence of an emerging tick-borne infection with rickettsia helvetica. we conducted a serosurvey in 168 danish patients seropositive for borreliosis reflecting their exposure to i. ricinus ticks. a total of 21 patients (12.5%) had positive antibody titres to r. helvetica including 4 cases of seroconversion. none of the samples were positive for antibodies to ehrlichia. we conclude that in ...	2004	15370666
no serological evidence of rickettsia helvetica infection in scandinavian sarcoidosis patients.	many agents have been suggested to elicit sarcoidosis, and, recently, an association was presented between this disease and the bacterium rickettsia helvetica. the aim of this study was to investigate if serological support for such an association could be detected. sera from 20 well-characterised sarcoidosis patients were investigated for anti-rickettsial immunoglobulin g antibodies with a micro-immunofluorescence technique. r. helvetica, r. conorii and r. typhi served as antigens. in conclusio ...	2004	15516677
evidence of rickettsia spp. infection in sweden: a clinical, ultrastructural and serological study.	sweden is an area potentially endemic for spotted fever rickettsioses. rickettsia helvetica has been isolated from its tick vector ixodes ricinus, and in a handful of cases linked to human disease. this study demonstrates for the first time in sweden the transmission of rickettsial infection after a tick bite and the attack rate in an endemic area. we present three cases of documented rickettsial infection and a prospective serological study of swedish recruits who were trained in the area where ...	2005	15723687
molecular evidence of rickettsia helvetica and r. monacensis infections in ixodes ricinus from hungary.		2005	15829141
survey of tickborne infections in denmark.	we conducted a study of the distribution and prevalence of tickborne infections in denmark by using roe deer as sentinels. blood samples from 237 roe deer were collected during the 2002-2003 hunting season. overall, 36.6% of deer were borrelia seropositive, while 95.6% were anaplasma phagocytophilum positive; all animals were negative for bartonella quintana and b. henselae by indirect immunofluorescence assay. when a hemagglutination-inhibition test was used, 8.7% of deer were found positive fo ...	2005	16022780
detection of rickettsial dna in ixodid ticks recovered from dogs and cats in japan.	dna from ticks recovered from 1137 dogs and 133 cats from all over japan were examined for rickettsia infection by citrate synthase gene (glta)-based pcr and partial nucleotide sequencing. a total of 91 dog tick samples and 18 cat tick samples showed a single band of the appropriate size in the nested pcr. sequence analysis was successfully performed on 102 samples. dna of rickettsia japonica or closely related rickettsia spp. strains were detected from 38 ticks in 16 prefectures mainly in weste ...	2005	16397379
[rickettsia helvetica: an emerging tick-borne pathogen in hungary and europe].	rickettsia helvetica belonging to spotted fever group rickettsiae was recently detected by polymerase chain reaction followed by sequencing in european sheep ticks (ixodes ricinus) from hungary. current knowledge on these rickettsiae and the clinical and diagnostic aspects of r. helvetica infection is summarized. in acute cases, r. helvetica is generally responsible for flu-like symptoms. nevertheless, recent data indicate that in chronic cases, these rickettsiae can be responsible for perimyoca ...	2005	16440500
rickettsiae of the spotted-fever group in ixodid ticks from hungary: identification of a new genotype ('candidatus rickettsia kotlanii').	three common european 'anthrophilic' ticks, ixodes ricinus, haemaphysalis concinna and dermacentor reticulatus, were collected in hungary and tested, in assays based on nested pcr, for rickettsiae of the spotted-fever group. low percentages of i. ricinus (2.7%) and h. concinna (1.0%) and a high percentage of d. reticulatus (26.8%) were found to be infected. the rickettsiae in the ticks were then identified, by sequencing of the genes coding for 16s ribosomal rna (16s rdna), citrate synthase (glt ...	2006	16630380
serological evidence of rickettsia infections in forestry rangers in north-eastern italy.	the prevalence of antibodies to rickettsiae and other tick-borne microrganisms in the sera of 181 forestry rangers from friuli-venezia-giulia, italy, was examined. seven (3.9%) sera were positive for rickettsia conorii and rickettsia helvetica, as single or dual infections; four of these sera had been found previously to be positive for borrelia burgdorferi. antibodies to coxiella burnetii were detected in five (2.8%) sera, four of which were also positive for b. burgdorferi. these findings indi ...	2006	16643531
causes of acute, undifferentiated, febrile illness in rural thailand: results of a prospective observational study.	the adult patients who, between july 2001 and june 2002, presented at any of five hospitals in thailand with acute febrile illness in the absence of an obvious focus of infection were prospectively investigated. blood samples were taken from all of the patients and checked for aerobic bacteria and leptospires by culture. in addition, at least two samples of serum were collected at different times (on admission and 2-4 weeks post-discharge) from each patient and tested, in serological tests, for ...	2006	16762116
impact of the excision of an ancient repeat insertion on rickettsia conorii guanylate kinase activity.	the genomic sequencing of rickettsia conorii revealed a new family of rickettsia-specific palindromic elements (rpes) capable of in-frame insertion in preexisting open reading frames (orfs). many of these altered orfs correspond to proteins with well-characterized or essential functions in other microorganisms. previous experiments indicated that rpe-containing genes are normally transcribed and that no excision of the repeat occurs at the mrna level. using mass spectrometry, we now confirmed th ...	2006	16891376
current knowledge of rickettsial diseases in italy.	rickettsial diseases continue to be the cause of serious health problems in italy. from 1998 to 2002, 4,604 clinical cases were reported, with 33 deaths in the period from 1998 to 2001. almost all the cases reported in italy are cases of mediterranean spotted fever (msf). other rickettsioses that have been historically documented are murine typhus and epidemic typhus. since 1950, only sporadic cases of murine typhus have been reported, and italy currently appears to be free of epidemic typhus. a ...	2006	17114696
rickettsia spp. in ixodes ricinus ticks in bavaria, germany.	this study aims to provide information on the occurrence of spotted fever rickettsiae in ixodes ricinus ticks in southern germany. a total of 2,141 i. ricinus ticks was collected in bavaria. pools of 5-10 ticks were studied by a pcr targeting the rickettsial citrate synthase gene glta. the average prevalence rate was 12% (257 of 2,141). sequencing data exclusively identified rickettsia helvetica dna. results and other data demonstrate the possible role of r. helvetica in i. ricinus as a source o ...	2006	17114766
the occurrence of spotted fever group (sfg) rickettsiae in ixodes ricinus ticks (acari: ixodidae) in northern poland.	ixodes ricinus, the most commonly observed tick species in poland, is known vector of microorganisms pathogenic for humans as tbe virus, borrelia burgdorferi s.1., anaplasma phagocytophilum and babesia sp. in this country. our study aimed to find out whether this tick can also transmit also rickettsiae of the spotted fever group (sfg). dna extracts from 560 ticks (28 females, 34 males, and 488 nymphs) collected in different wooded areas in northern poland were examined by pcr for the detection o ...	2006	17114767
pathogens and host dna in ixodes ricinus nymphal ticks from a german forest.	unfed nymphs of ixodes ricinus were collected from vegetation in a forest on the outskirts of berlin, germany and were analyzed for host and pathogen dna. pathogens were detected in 47% of the ticks. borrelia afzelii was the commonest pathogen detected, followed by rickettsia helvetica. other pathogens included b. valaisiana, b. garinii, b. burgdorferi sensu stricto, anaplasma phagocytophilum, and a relapsing fever-like borrelia. most of the host dna detected was of rodent origin and was associa ...	2006	17187573
detection and identification of anaplasma phagocytophilum, borrelia burgdorferi, and rickettsia helvetica in danish ixodes ricinus ticks.	borreliosis is an endemic infection in denmark. recent serosurveys have indicated that human anaplasmosis may be equally common. the aim of this study was to look for anaplasma phagocytophilum and related pathogens in ixodes ricinus ticks and estimate their prevalence, compared to borrelia, using pcr. ticks were collected from three locations in denmark: jutland, funen, and bornholm. ticks from jutland and funen were analysed individually, ticks from bornholm were analysed in pools of 20. a. pha ...	2007	17367468
prevalence of tick-borne rickettsia and ehrlichia in ixodes persulcatus and ixodes ovatus in tokachi district, eastern hokkaido, japan.	dna from 111 ticks collected by flagging in tokachi district, eastern hokkaido, japan were examined for infection with rickettsia and ehrlichia, by pcr and sequencing methodology. for rickettsia, analysis of the partial sequence of the citrate synthase gene was successfully performed on 11 dna samples from i. persulcatus, and 7 of them showed 99.8% identical with rickettsia helvetica while the other 4 showed 99.8% identical with ;candidatus rickettsia tarasevichiae'. for ehrlichia, a partial seq ...	2007	17611367
ticks and associated pathogens collected from domestic animals in the netherlands.	following an outbreak of autochthonous canine babesiosis in the netherlands, a request made to veterinarians and the public to collect ticks from companion animals resulted in 4298 ticks submitted between july 2005 and october 2006 to our center. ticks were identified as ixodes ricinus adults (2907/4298, 67.6%), ixodes sp. nymphs (529/4298, 12.3%) and ixodes sp. larvae (385/4298, 9.0%), i. hexagonus adults (328/4298, 7.6%), dermacentor reticulatus (72/4298, 1.7%), and several other exotic tick s ...	2007	17979540
detection of rickettsia helvetica dna from peripheral blood of sika deer (cervus nippon yesoensis) in japan.	partial nucleotide sequences of the citrate synthase and 17-kda genes of rickettsia helvetica were detected from peripheral blood samples of sika deer (cervus nippon yesoensis) in hokkaido, japan. results suggest the presence of a rickettsiemia associated with r. helvetica. this is the first evidence of r. helvetica infection in sika deer and indicates that this species may represent a potential reservoir host of r. helvetica in japan.	2008	18263833
first detection of rickettsia helvetica in ixodes ricinus ticks in austria.	a total of 853 ixodes ricinus ticks collected from the nine federal states of austria were examined by molecular methods for possible infections with rickettsia spp. it was shown that roughly one-third of the ticks were infected with rickettsia spp. moreover, rickettsia helvetica was detected in austria for the first time.	2008	18447624
detection and identification of rickettsia species in the northeast of italy.	this study was carried out using ixodes ricinus ticks collected during 2005 and 2006 from the friuli venezia giulia (fvg) region in the northeastern part of italy and an area along the slovenian side of the western border of italy. the results indicate that rickettsia spp. is widely distributed throughout these areas, with the greatest prevalence in the central part of the fvg region. the prevalence of rickettsia spp. was 4.5% during 2005 and 6.1% during 2006. by sequencing the 16s rrna gene, we ...	2008	18637720
serological and molecular survey of rickettsial infection in cattle and sika deer in a pastureland in hidaka district, hokkaido, japan.	rickettsial infection of cattle and sika deer from a pastureland in hidaka district, hokkaido, japan was examined by serological and molecular methods. serum samples from 8 of 83 (9.6%) cattle reacted with rickettsia helvetica antigens in an ifa test, with titers ranging from 1:160 to 1:640, while serum samples from 15 of 22 (68.2%) deer were positive for r. helvetica, with titers ranging from 1:80 to 1:640. in a genus-specific nested pcr based on glta, no cattle were positive for rickettsia, wh ...	2008	18653979
first report of rickettsia monacensis and rickettsia helvetica from tunisia.		2008	18782496
prevalence of spotted fever group rickettsiae in ixodes ricinus (acari: ixodidae) in southern germany.	host-seeking ixodes ricinus (l.) (acari: ixodidae) ticks were collected systematically, from may to september 2006, at selected sites in southern germany, including a large city park in munich. polymerase chain reactions for amplification of genes of the rickettsial citrate synthase (glta), the outer membrane proteins a and b (ompa and ompb), and the 16s rdna were used to investigate 2,861 specimens (adults and nymphs). glta sequences of spotted fever group rickettsiae were detected in 151 of al ...	2008	18826040
incidence of various tick-borne microorganisms in rodents and ticks of central slovakia.	in this study, we detected rickettsia helvetica, candidatus midichloria mitochondrii, anaplasma phagocytophilum, ehrlichia muris, candidatus neoehrlichia mikurensis, and bartonella sp. infections in wild rodents and ticks collected from the vegetation of central slovakia. the microorganisms were identified by pcr and sequencing. yellow-necked mice (apodemus flavicollis) were infected with e. muris and bartonella sp., while ticks ixodes ricinus collected from the vegetation were infected with r. ...	2008	18999892
spread of ticks and tick-borne diseases in germany due to global warming.	tick-transmitted diseases like tick-borne encephalitis and lyme borreliosis have been well known in germany for decades. global climate changes may influence the emergence and reemergence of diseases. ongoing research now gives an additional focus on other tick-borne pathogens such as coxiella burnetii, rickettsia conorii, anaplasma phagocytophilum and babesia spp., the causative agents of q-fever, mediterranean spotted fever, anaplasmosis and babesiosis, respectively. the epidemiology of these ...	2008	19030892
[prevalence of tick-borne encephalitis virus and rickettsiae in ticks of the district burgenland, austria].	large areas of the central european country austria are known to be endemic for tick-borne encephalitis virus (tbev). however, so far only limited data are available for the prevalence, distribution and species composition of rickettsiae of the spotted fever group in austria. in the present study 306 ticks were collected in summer 2007. location of sampling was neudörfl, a known tbev endemic area in the district of burgenland in eastern austria. 286 ticks belonged to the species ixodes ricinus a ...	2008	19066772
seroprevalence of rickettsia spp. infection among tick-bitten patients and blood donors in sweden.	serum samples from 236 swedish patients with symptoms of infectious disease appearing after a tick bite were analysed for the presence of antibodies to rickettsia helvetica, the only rickettsial species so far isolated from ticks in sweden. of these subjects, 137 had tested seropositive for borrelia burgdorferi. for control purposes, sera from 161 healthy blood donors were examined. a total of 10/397 samples (2.6%) showed igg-antibodies to r. helvetica at or above a titre of 1/80 as cut-off. 6/1 ...	2008	17852905
determination of rickettsial and antinuclear antibodies in danish patients with sarcoidosis.	rickettsia helvetica has been proposed as an aetiological agent in sarcoidosis.	2008	20298335
detection of rickettsia spp. in danish ticks (acari: ixodes ricinus) using real-time pcr.	we examined 192 ixodes ricinus tick nymphs from denmark for the presence of rickettsia spp. we used a species-specific real-time pcr; 13.0% of the ticks were positive for rickettsial dna. only dna from rickettsia helvetica was found in the ticks.	2009	19096982
rickettsia helvetica in dermacentor reticulatus ticks.	we report on the molecular evidence that dermacentor reticulatus ticks in croatia are infected with rickettsia helvetica (10%) or rickettsia slovaca (2%) or co-infected with both species (1%). these findings expand the knowledge of the geographic distribution of r. helvetica and d. reticulatus ticks.	2009	19116063
molecular investigations of rickettsia helvetica infection in dogs, foxes, humans, and ixodes ticks.	rickettsia helvetica, a tick-borne member of the spotted-fever-group rickettsiae, is a suspected pathogen in humans; however, its role in animals is unknown. the aims of this study were to establish a r. helvetica-specific real-time taqman pcr assay and apply it to the analysis of tick vectors (to determine potential exposure risk) and blood samples from canidae and humans (to determine prevalence of infection). the newly designed 23s rrna gene assay for r. helvetica was more sensitive than a pu ...	2009	19329665
a study of the antigenicity of rickettsia helvetica proteins using two-dimensional gel electrophoresis.	rickettsia helvetica is an obligate intracellular gram-negative microorganism found in ixodes ricinus ticks. when r. helvetica was first discovered in 1979, little was known about its physiology and it fell into oblivion until it recently was suspected of being pathogenic to humans. however, all efforts to isolate r. helvetica from patients have been unsuccessful, although serological responses against r. helvetica can be demonstrated. the aim of our study was to investigate the protein profile ...	2009	19338513
typhus and other rickettsioses: emerging infections in germany.	rickettsioses are diseases caused by rickettsiae, obligate intracellular bacteria that are transmitted by arthropods to humans. they cause various types of spotted fever and typhus.	2009	19547738
septicaemia with rickettsia helvetica in a patient with acute febrile illness, rash and myasthenia.	the spotted fever rickettsia, rickettsia helvetica, is mostly reported to present a flu-like self-limiting disease. in the present case, however, where the presence of r. helvetica in the blood was verified by pcr together with serologic evidence of infection, the patient presented a different clinical picture with acute febrile illness, rash and long-lasting myasthenia.	2009	18649945
a prospective study evaluating the presence of rickettsia in danish patients with sarcoidosis.	rickettsia helvetica has previously been proposed as an aetiological agent in sarcoidosis. the purpose of the present study was to detect possible signs of rickettsia infection in a danish population of patients with sarcoidosis. twenty-six patients with newly diagnosed sarcoidosis were prospectively enrolled in the study. the diagnosis was confirmed by biopsy in 18 and by clinical characteristics in 8 patients; 11 patients with different non-sarcoid lung diseases were recruited as controls. we ...	2009	19685374
ixodes ricinus ticks are reservoir hosts for rickettsia helvetica and potentially carry flea-borne rickettsia species.	abstract:	2009	19732416
prevalence of infection with rickettsia helvetica in feeding ticks and their hosts in western poland.		2009	19793116
the first detection of babesia eu1 and babesia canis canis in ixodes ricinus ticks (acari, ixodidae) collected in urban and rural areas in northern poland.	ixodes ricinus, the most commonly observed tick species in poland, is a known vector of such pathogenic microorganisms as tbe viruses, borrelia burgdoferi sensu lato, anaplasma phagocytophilum, rickettsia helvetica, babesia divergens and b. microti in our country. our study aimed to find out whether this tick can also transmit other babesiae of medical and veterinary importance. dna extracts of 1392 ticks (314 nymphs, 552 male and 526 female ticks) collected in urban and rural areas in the pomer ...	2009	19899616
prevalence of five pathogenic agents in questing ixodes ricinus ticks from western france.	in europe, ixodes ricinus ticks are vectors of many emerging pathogens, including borrelia burgdorferi sensu lato (sl), anaplasma phagocytophilum, spotted fever group rickettsia sp., babesia sp., and very likely bartonella sp. in this study, we looked for the presence of dna of these microorganisms in 572 ticks from two forests in the west of france. dna extraction and polymerase chain reaction (pcr) amplification were performed on individual nymphal, male, and female i. ricinus ticks. amplifica ...	2010	20020814
dissemination of spotted fever rickettsia agents in europe by migrating birds.	migratory birds are known to play a role as long-distance vectors for many microorganisms. to investigate whether this is true of rickettsial agents as well, we characterized tick infestation and gathered ticks from 13,260 migratory passerine birds in sweden. a total of 1127 ixodes spp. ticks were removed from these birds and the extracted dna from 957 of them was available for analyses. the dna was assayed for detection of rickettsia spp. using real-time pcr, followed by dna sequencing for spec ...	2010	20052286
rickettsia helvetica in patient with meningitis, sweden, 2006.	pathogenicity of rickettsia helvetica is relatively unknown. we isolated a spotted fever group rickettsial organism from a patient with subacute meningitis. nucleotide sequences of the 16s rrna, ompb, and 17kda genes identified the isolate as r. helvetica. this organism may be associated with serious infections such as central nervous system disorders.	2010	20202426
molecular investigation of hard ticks (acari: ixodidae) and fleas (siphonaptera: pulicidae) as potential vectors of rickettsial and mycoplasmal agents.	the aim of the present study was twofold. first, in general, to reveal new aspects of the potential vector role of ixodid ticks and fleas by screening large numbers of specimens with recently developed molecular biological methods. second, to evaluate the occurrence of vector-borne infectious agents in a geographical context. altogether 3442 unfed hard ticks (ixodes ricinus, dermacentor marginatus, d. reticulatus, haemaphysalis inermis, h. concinna, h. punctata) and 939 fleas of cats and dogs (c ...	2010	19660880
coinfections of rickettsia slovaca and rickettsia helvetica with borrelia lusitaniae in ticks collected in a safari park, portugal.	borrelia and rickettsia bacteria are the most important tick-borne agents causing disease in portugal. identification and characterization of these circulating agents, mainly in recreational areas, is crucial for the development of preventive measures in response to the gradually increasing exposure of humans to tick vectors. a total of 677 questing ticks including dermacentor marginatus, rhipicephalus sanguineus, ixodes ricinus, hyalomma lusitanicum, h. marginatum, and haemaphysalis punctata we ...	2010	21771525
role of sand lizards in the ecology of lyme and other tick-borne diseases in the netherlands.	abstract:	2010	20470386
detection and prevalence of anaplasma phagocytophilum and rickettsia helvetica in ixodes ricinus ticks in seven study areas in sweden.	abstract:	2010	20684755
established and emerging pathogens in ixodes ricinus ticks collected from birds on a conservation island in the baltic sea.	tick-borne pathogens such as lyme borreliosis spirochaetes, anaplasma phagocytophilum, rickettsia spp. and babesia spp. cause a great variety of diseases in animals and humans. although their importance with respect to emerging human diseases is increasing, many issues about their ecology are still unclear. in spring 2007, 191 ixodes ricinus (acari: ixodidae) ticks were collected from 99 birds of 11 species on a bird conservation island in the baltic sea in order to test them for borrelia spp., ...	2010	20868431
first detection of spotted fever group rickettsiae in ixodes ricinus and dermacentor reticulatus ticks in the uk.	a preliminary study was conducted to determine the presence of spotted fever rickettsiae in two species of british tick (ixodes ricinus and dermacentor reticulatus). the 16s rrna gene of rickettsia spp. was detected in 39/401 (9·7%) of ticks tested, including 22/338 (6·5%) i. ricinus and 17/63 (27%) d. reticulatus. some positive i. ricinus samples showed 100% homology with rickettsia helvetica (10/22), and most positive d. reticulatus showed 100% homology with r. raoultii (13/17). five other ric ...	2010	21087541
first detection of spotted fever group rickettsiae in ticks in serbia.	ticks can transmit multiple pathogenic bacteria responsible for diseases in animals and humans such as borrelia burgdorferi sensu lato, anaplasma phagocytophilum, and spotted fever group rickettsia sp. the current study aimed to investigate the presence of rickettsiae in ticks collected from seven localities in serbia. one hundred thirty-one (131) questing ticks belonging to 5 tick species (dermacentor marginatus, dermacentor reticulatus, haemaphysalis punctata, haemaphysalis concinna, and ixode ...	2010	21142961
seasonal and habitat variation in the prevalence of rickettsia helvetica in ixodes ricinus ticks from denmark.	a total of 704 unfed ticks of the species ixodes ricinus collected in denmark were screened for rickettsia dna by a genus-specific real-time pcr. of the nymphs, 4.7% (31/662) were positive for rickettsial dna. among the positive ticks, we observed a seasonal and habitat variation. the infection rate was highest in may as compared to july, august, and october. ecotone (high tick density) showed an elevated prevalence as compared to spruce or beech forests. sequencing revealed only dna from r. hel ...	2010	21771515
[insect-borne diseases and insect bites in finland].	clinically significant endemic, arthropod-borne infectious diseases in finland include lyme disease, tick-borne encephalitis, tularemia and karelian fever. the diagnosis of early borreliosis or tularemia is clinical and the treatment is initiated already before the results of eventual blood tests. the diagnosis of late stage borreliosis, tick-borne encephalitis or karelian fever is confirmed mainly with serologic tests. the clinical significance of endemic anaplasmosis, rickettsia helvetica, ink ...	2011	21834346
is sarcoidosis a rickettsiosis? an archival study.	based on earlier research, rickettsia helvetica could possibly be involved in the pathogenesis of sarcoidosis. rickettsiae are transmitted to humans by a tick vector, ixodes ricinus; this tick is highly prevalent in northern europe. we aimed to investigate the association between evidence of rickettsiae and sarcoidosis in histological samples.	2011	21284566
is sarcoidosis a rickettsiosis?	the pathogenesis of sarcoidosis is still largely unknown. the generally accepted theory is that genetically predisposed individuals develop the sarcoid disease reaction as a response to one or more unknown antigen(s). a single study by nilsson et al has related the development of sarcoidosis to an infection with rickettsia helvetica. the aim of this thesis was to investigate whether a rickettsial infection is involved in the pathogenesis of sarcoidosis. we used different microbiological methods ...	2011	21299929
the importance of ixodes arboricola in transmission of rickettsia spp., anaplasma phagocytophilum, and borrelia burgdorferi sensu lato in the czech republic, central europe.	abstract wild birds are known to be a reservoir of infectious disease agents and disseminatory hosts of ticks. the purpose of this work was to obtain information about the occurrence of rickettsial, anaplasmal, and borrelial infections in some ticks that parasitize wild birds in the czech republic. a total of 549 subadult ticks of three species ixodes arboricola (75.0%), ixodes ricinus (23.1%), and haemaphysalis concinna (1.8%) were collected from 20 species of birds (passeriformes). rickettsiae ...	2011	21612531
co-circulation of emerging tick-borne pathogens in middle germany.	abstract from may until october 2007, a total of 658 ixodes ricinus ticks were collected off birds (189), rodents (273), and vegetation (196) in a certain area of middle germany and investigated for infection with babesia spp., anaplasma phagocytophilum, and rickettsia spp. overall, 13.1% (86/658) of the ticks were infected with at least one pathogen; co-infections occurred in 0.6% (4/658). babesia spp. specific dna was detected in 9.7% (64/658) of the ticks, 1.4% (9/658) were infected with a. p ...	2011	20846013
detection of babesia sp. eu1 and members of spotted fever group rickettsiae in ticks collected from migratory birds at curonian spit, north-western russia.	to reveal the prevalence of spotted fever group (sfg) rickettsiae and babesia sp. in ixodes ricinus (l.) ticks from migratory birds, 236 specimens represented 8 species of passeriformes and were collected at curonian spit in kaliningrad enclave of north-western russia. the ticks (total 126) being detached from four bird species, turdus philomelos, fringilla coelebs, parus major, and sturnus vulgaris, were investigated by pcr using the primers rp cs.877p/rp cs.1258n for the detection of rickettsi ...	2011	20553110
Evaluation of clinical specimens for Rickettsia, Bartonella, Borrelia, Coxiella, Anaplasma, Franciscella and Diplorickettsia positivity using serological and molecular biology methods.	We monitored clinical samples from patients of different age groups from selected regions in Slovakia. Overall seroprevalence evaluated by immunofluorescence (IFA) using nine Bartonella, two Borrelia, six rickettsial (spotted fever and typhus group), two Coxiella, and one human granulocytic ehrlichiosis Anaplasma, Franciscella tularensis and Diplorickettsia massiliensis antigens, in rural and city populations of Slovak Republic, was found to be 32% positive for spotted fever group rickettsiae. O ...	2011	22098390
life cycle, growth characteristics and host cell response of rickettsia helvetica in a vero cell line.	rickettsia helvetica, a spotted fever rickettsia and emerging pathogen with ixodes ricinus ticks as the main vector, is an agent of human disease and may cause febrile illness as well as meningitis. in three parallel series the isolated standard type of r. helvetica, obtained from a pcr-positive i. ricinus tick, was high-passaged and propagated in a vero cell line. by using quantitative real-time pcr, the generation time from inoculation to stationary phase of growth was calculated to 20-22 h. i ...	2011	22116301
first molecular evidence of anaplasma ovis and rickettsia spp. in keds (diptera: hippoboscidae) of sheep and wild ruminants.	to evaluate the presence of rickettsial agents in hippoboscid flies with molecular methods, 81 sheep keds (melophagus ovinus) were collected from 23 sheep, 144 deer keds (lipoptena cervi) were caught in the environment, and a further 463 and 59 individuals of the latter species were obtained from fresh carcasses of 29 red deer and 17 roe deer, respectively. dna was extracted individually or in pools. anaplasma ovis was demonstrated in all examined sheep keds, and from one pool of free-living dee ...	2011	21923269
coinfection with rickettsia helvetica and herpes simplex virus 2 in a young woman with meningoencephalitis.	herpes virus type 2 dna was detected by pcr in the cerebrospinal fluid in a young woman presenting with headache, stiff neck and pleocytosis, and serological findings consistent with reactivation. since she was exposed to ticks, lyme disease and tick-borne encephalitis were excluded. further investigation in an ongoing project, using pcr and sequencing of the amplified products, showed the presence of rickettsia helvetica in the cerebrospinal fluid. the bacteria were also isolated in vero cell c ...	2011	22567472
infections and coinfections of questing ixodes ricinus ticks by emerging zoonotic pathogens in western switzerland.	in europe, ixodes ricinus is the vector of many pathogens of medical and veterinary relevance, among them borrelia burgdorferi sensu lato and tick-borne encephalitis virus, which have been the subject of numerous investigations. less is known about the occurrence of emerging tick-borne pathogens like rickettsia spp., babesia spp., "candidatus neoehrlichia mikurensis," and anaplasma phagocytophilum in questing ticks. in this study, questing nymph and adult i. ricinus ticks were collected at 11 si ...	2012	22522688
role of the lizard teira dugesii as a potential host for ixodes ricinus tick-borne pathogens.	pcr screening of ticks and tissue samples collected from 151 teira dugesii lizards seems to indicate a potential role of this lizard species in the maintenance and transmission cycle of some ixodes ricinus tick-borne agents, such as rickettsia monacensis, rickettsia helvetica, and borrelia lusitaniae, that are circulating on madeira island.	2012	22407681
occurrence and identification of risk areas of ixodes ricinus-borne pathogens: a cost-effectiveness analysis in north-eastern italy.	ixodes ricinus, a competent vector of several pathogens, is the tick species most frequently reported to bite humans in europe. the majority of human cases of lyme borreliosis (lb) and tick-borne encephalitis (tbe) occur in the north-eastern region of italy. the aims of this study were to detect the occurrence of endemic and emergent pathogens in north-eastern italy using adult tick screening, and to identify areas at risk of pathogen transmission. based on our results, different strategies for ...	2012	22452970
multiple tick-associated bacteria in ixodes ricinus from slovakia.	eighty ixodes ricinus ticks collected in the rovinka forest in slovakia were tested by real-time and routine single-step pcr for the presence of different pathogenic and endosymbiotic bacteria. no evidence of coxiella burnetii, diplorickettsia massiliensis, or bartonella spp. was found. however, we identified, as the pathogenic bacteria, anaplasma phagocytophilum in 8%, rickettsia helvetica in 11%, borrelia afzelii in 9%, bo. garinii in 8%, bo. burgdorferi sensu stricto in 5%, bo. valaisiana in ...	2012	23182274
tick-borne zoonotic pathogens in ticks feeding on the common nightingale including a novel strain of rickettsia sp.	we examined 77 ixodes ricinus ticks found on 33 out of 120 common nightingales (luscinia megarhynchos) sampled in the czech republic in 2008 for the presence of borrelia spirochetes, anaplasma phagocytophilum, rickettsia spp., and babesia spp. we detected borrelia garinii (in 4% of ticks), a. phagocytophilum (1%), rickettsia helvetica (3%), a novel strain of rickettsia sp. (sister taxon of r. bellii; 1%), and babesia sp. eu1 (1%). thus, we conclude that nightingales are unlikely to be important ...	2012	22906497
study on ticks and tick-borne zoonoses in public parks in italy.	a survey on tick density and on tick-borne zoonoses was carried out in four public parks in the outskirts of imola (northern italy) from june to october 2006. all stages of ixodes ricinus and only larvae of riphicephalus sanguineus were recovered by dragging, performed on 100-m transects. almost all ticks (99%) were harvested in one park. i. ricinus density (nymphs/100 m(2) ) ranged from 0 in park l to 6.3 in park f. nymphs and adults of i. ricinus were subjected to pcr for anaplasma phagocytoph ...	2012	22551055
prevalence of rickettsia spp., anaplasma phagocytophilum, and coxiella burnetii in adult ixodes ricinus ticks from 29 study areas in central and southern sweden.	a total of 887 adult ixodes ricinus ticks (469 females and 418 males) from 29 different localities in sweden were screened for rickettsia, anaplasma, and coxiella dna using pcr and then subjected to gene sequencing. rickettsial dna was detected in 9.5-9.6% of the ticks. most of the positive ticks were infected with rickettsia helvetica. one tick harbored another spotted fever rickettsia, closely related to or identical with r. sibirica not previously found in i. ricinus nor in sweden. six of the ...	2012	22487426
seasonal activity and tick-borne pathogen infection rates of ixodes ricinus ticks in hungary.	ixodes ricinus is the most important tick species in europe as it is most widely distributed and transmits the majority of tick-borne zoonotic pathogens. as limited data are available for hungary, the aim of the present study was to investigate the seasonal timing of questing by i. ricinus and the infection rate of this tick species with all major tick-borne zoonotic pathogens. monthly collections of i. ricinus were carried out over 3 consecutive years by dragging a blanket in 6 biotopes represe ...	2012	22445929
tick-borne rickettsioses in europe.	rickettsioses are caused by obligate intracellular bacteria within the genus rickettsia, mainly transmitted by arthropods. until recently, mediterranean spotted fever (msf) caused by rickettsia conorii was considered the only tick-borne rickettsiosis in europe. however, 'new' tbr have been described in europe during last years. for instance, other subspecies such as r. conorii caspia and r. conorii israelensis have been involved in msf. dermacentor-borne necrosis erythema and lymphadenopathy/tic ...	2012	23177355
spotted fever group rickettsiae identified in dermacentor marginatus and ixodes ricinus ticks in algeria.	our study was carried out using ixodes ricinus ticks collected from cattle from tizi-ouzou and dermacentor marginatus ticks collected from the vegetation of the blida region, a tourist site, both regions situated in northern algeria. the results of real-time quantitative pcr (qpcr) specific for a partial sequence of the citrate synthase gene (glta) indicate that rickettsia spp. were present in 11/23 (48%) and 4/9 (44%) of the examined ticks from tizi-ouzou and blida, respectively. the sequences ...	2012	23168054
detection of rickettsia helvetica in ixodes ricinus ticks collected from pyrenean chamois in france.	seventy-one ixodes ricinus ticks collected from pyrenean chamois (rupicapra pyrenaica) in the french pyrenees were tested by real-time polymerase chain reaction to detect the presence of rickettsia and bartonella. four ticks (6%) were positive for r. helvetica. the chamois carries infected ticks, and this enables the dissemination throughout the environment with this bacterium, a potential human pathogen.	2012	23141107
isolation of rickettsia helvetica from ticks in slovakia.	to date, only three rickettsial species have been found in ticks in slovakia by serological and/or molecular-biological techniques, namely rickettsia slovaca, candidatus rickettsia irs, and rickettsia raoultii. recently, we succeeded in isolation of the forth species, rickettsia helvetica from ixodes ricinus, the most frequent tick in slovakia. the isolation, positive for 10% of tested ticks, was performed on xtc cells by the shell-vial technique, gimenez staining and light microscopy. the infec ...	2012	23043605
lyme borreliosis spirochetes and spotted fever group rickettsiae in ixodid ticks from pianosa island, tuscany archipelago, italy.	a study on tick fauna and tick-borne pathogens was undertaken in pianosa, an island in the tuscany archipelago that constitutes an important stopping and nesting point for migratory birds. ticks were removed from feral cats and a few terrestrial birds, and host-seeking ticks were collected by dragging. a total of 89 ticks were found on animals: 57 ixodes ventalloi gil collado, 1936 and 32 ixodes acuminatus neumann, 1901. host-seeking ticks were 354 hyalomma spp. larvae and 18 hyalomma spp. adult ...	2013	23289398
survey on tick-borne pathogens in thoroughbred horses in the hidaka district, hokkaido, japan.	a total of 87 thoroughbred horses and 10 ixodid ticks from a ranch in hidaka district, hokkaido were tested for tick-borne diseases. using the indirect fluorescent antibody (ifa) method, 3.4, 92.0 and 97.7% of the horses showed antibody titers of ≥ 80 against anaplasma phagocytophilum, rickettsia helvetica, and borrelia garinii, respectively. this is the first report of infection with the 3 pathogens in horses in japan. using pcr, dnas from the peripheral blood of all horses were found negative ...	2013	22878540
vector-borne pathogens in ticks and edta-blood samples collected from client-owned dogs, kiev, ukraine.	due to the availability of adequate habitats in urban environments, e.g. city parks and recreational green areas, ticks from such settings may also carry pathogens of veterinary and public health concern. thus, tick-borne infections may readily be identified in companion animals residing in urbanised areas. to investigate the presence of vector-borne pathogens in kiev, ukraine, 52 engorged adult ticks, 33 dermacentor reticulatus and 19 ixodes ricinus, were collected from 15 dogs in the spring of ...	2013	23069260
anaplasma phagocytophilum and rickettsia spp. infections in hard ticks (ixodes ricinus) in the city of hanover (germany): revisited.	the present study aimed to determine the prevalence of rickettsiales (a. phagocytophilum and rickettsia spp.) in 2100 i. ricinus ticks collected at 10 different sampling sites every month during the tick season 2010 in the city of hanover, northern germany. at the same time, the results served as a fifth-year-follow-up study to monitor whether changes or stagnation of tick infection rates - possibly due to climate change--were obvious or not. to detect infections with a. phagocytophilum and/or r ...	2013	23838023
molecular detection of tick-borne pathogens in ixodes ricinus from moldova collected in 1960.	this study is the first report about the prevalence of tick-borne pathogens, as well as their (co-)infection rates, in the museum-archived i. ricinus female ticks collected in moldova in 1960. a total of 16.7% (21/126) ticks was mono-infected. borrelia burgdorferi sensu stricto was revealed as the most abundant species (4.8%) followed by b. garinii (1.6%), b. afzelii (0.8%), b. valaisiana (0.8%), and b. lusitaniae (0.8%). dna of rickettsia helvetica (2.4%), r. monacensis (2.4%), anaplasma phagoc ...	2013	23528990