| genotypic identification and phylogenetic analysis of the spotted fever group rickettsiae by pulsed-field gel electrophoresis. | using pulsed-field gel electrophoresis, we studied the chromosomes of spotted fever group rickettsiae. we digested the dna of 16 species currently known to belong to this group with smai, eagi, and bsshii. the genome size of 13 rickettsiae was between 1,200 and 1,300 kb. "rickettsia massiliae" and "r. helvetica" genome sizes were 1,370 and 1,397 kb, respectively, and that of r. bellii was 1,660 kb. it was possible to obtain distinctive patterns for each species, but in r. conorii, 10 isolates ex ... | 1993 | 8393009 |
| phylogenetic analysis of the genus rickettsia by 16s rdna sequencing. | rickettsiae are gram-negative bacteria which multiply only inside host cells and need arthropods either as reservoirs or as vectors. using the polymerase chain reaction and an automated laser fluorescent dna sequencer, we amplified and sequenced the 16s rrna (rdna) of all available bacteria of the genus rickettsia. r. tsutsugamushi remained close to the other bacteria of the genus rickettsia using this technique, contrary to previous conclusions based on the study of the sta-58 protein antigen. ... | 1995 | 8525055 |
| genetic variation in australian spotted fever group rickettsiae. | rickettsiae were isolated by cell culture of buffy coat blood from six patients with spotted fever from southeastern australia and flinders island in bass strait. the isolates were genetically compared with two previous rickettsia australis patient isolates. the genus-specific 17-kda genes from the isolates were compared after dna amplification and restriction fragment analysis of the amplified dna. this comparison revealed that mainland rickettsial isolates from southeastern australia were iden ... | 1996 | 8735110 |
| protein characterization of australian spotted fever group rickettsiae and monoclonal antibody typing of rickettsia honei. | rickettsial proteins romp a and romp b exist in both rickettsia australis and rickettsia honei but differ in molecular weight and antigenicity; in addition, they produce distinct immunogenic responses and appear to be to conformationally dependent antigens. species-specific monoclonal antibodies for other spotted fever group rickettsial species did not react with r. honei. a pcr product of the repeat region of the romp a gene from r. honei was amplified and calculated to contain 11 repeat units. | 1997 | 8968920 |
| 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 |
| emerging infections in australia. | over the last 10 years, novel infectious agents including equine morbillivirus, lyssavirus, barmah forest virus, rickettsia honei and two as-yet-unnamed bunyaviruses have been identified as causes of human disease in australia. previously described agents, such as japanese b encephalitis virus, dengue virus, ross river virus, orientia tsutsugamushi, rickettsia australis, burkholderia pseudomallei, mycobacterium ulcerans and trichinella pseudospiralis, have increased their geographical distributi ... | 1997 | 9494666 |
| vectors vs. humans in australia--who is on top down under? an update on vector-borne disease and research on vectors in australia. | australia has a diversity of vectors and vector-borne human diseases. mosquito-borne arboviruses are of greatest concern, but there are issues with other vector and pathogen systems. mosquitoes were responsible for more than 35,000 cases of ross river virus during 1991-1997. barmah forest virus is increasing nationwide, and unidentified bunyaviruses suspected of causing illness have been isolated. cases of murray valley encephalitis have occurred in 14 of the past 20 years in northern australia. ... | 1998 | 9673928 |
| detection of a spotted fever group rickettsia in amblyomma cajennense (acari: ixodidae) in south texas. | thai tick typhus rickettsia (strain tt-118), a spotted fever group rickettsia of indeterminant pathogenicity, was isolated from a mixed pool of larval ixodes and rhipicephalus ticks collected from thailand in 1962. here we report the surprising finding of a spotted fever group rickettsia with closest sequence homology to the thai tick typhus rickettsia in amblyomma cajennense (f.) ticks from south texas. sequence analysis was performed on segments of 3 genes that differentiate rickettsial specie ... | 1998 | 9701930 |
| phylogenetic analysis of spotted fever group rickettsiae by study of the outer surface protein rompa. | rickettsiae are classified in the order rickettsiales and have been included in the alpha subclass of the class proteobacteria on the basis of 16s rrna gene sequence comparison. to estimate the evolutionary forces that have shaped the members of the spotted fever group (sfg) rickettsiae, the ompa gene (apart from the tandem repeat units), encoding an antigenic high-molecular-mass membrane protein specific for the group, was amplified and sequenced from 21 isolates. the phylogenetic relationship ... | 1998 | 9734038 |
| rickettsia honei sp. nov., the aetiological agent of flinders island spotted fever in australia. | the name rickettsia honei, strain rbt, has been proposed for a unique spotted fever group (sfg) agent which is pathogenic for humans. this agent has previously been compared to the other sfg agents and was shown to be distinct in protein structure by sds-page and by immunoblotting. genetic comparisons of the 16s rrna, rompa, glta and the 17 kda antigen genes with the other sfg rickettsiae confirmed the phylogenetic distance between r. honei and the previously described species. genetically, rick ... | 1998 | 9828442 |
| 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 |
| short report: thai tick typhus, rickettsia honei, and a unique rickettsia detected in ixodes granulatus (ixodidae: acari) from thailand. | a unique rickettsia species (rickettsia thailandii sp. nov.) was identified in an ixodes granulatus by use of polymerase chain reaction heteroduplex mobility assay by use of segments of the citrate synthase gene. this tick was collected from rattus rattus from nakhon ratchasima province in 1970. another i. granulatus was infected with thai tick typhus strain tt-118, rickettsia honei sp. nov. stenos, roux, walker & raoult; this tick was removed from a r. rattus collected 4 years later from the sa ... | 2001 | 11716110 |
| rickettsia honei: a spotted fever group rickettsia on three continents. | rickettsia honei (also known as strain tt-118) has been detected on three continents. originally isolated in thailand in 1962 (and confirmed in 2001), it has also been detected on flinders island (australia) in 1993 and in texas (usa) in 1998. on each continent it has been associated with a different species of tick. the original isolate (thai tick typhus strain tt-118) was from a pool of larval ixodes and rhipicephalus ticks. later it was detected in i. granulatus from rattus rattus. its pathog ... | 2003 | 12860601 |
| ultrastructural and genetic evidence of a reptilian tick, aponomma hydrosauri, as a host of rickettsia honei in australia: possible transovarial transmission. | in 1993, a novel rickettsia was isolated from the blood of inhabitants of flinders island, australia, with acute febrile illnesses. this rickettsia was found to be a new species of spotted fever group (sfg) rickettsia, eventually named rickettsia honei. the suspected ectoparasite vector of this rickettsia has yet to be identified. the purpose of this study was to evaluate the presence of this rickettsial species in a suspected tick vector, aponomma hydrosauri, by dna sequencing and electron micr ... | 2003 | 12860602 |
| aponomma hydrosauri, the reptile-associated tick reservoir of rickettsia honei on flinders island, australia. | rickettsia honei is the etiologic agent of flinders island (australia) spotted fever. the tick aponomma hydrosauri is associated with reptiles and is the arthropod reservoir for this rickettsia on flinders island. the rickettsia appears to be maintained in the tick via vertical transmission. of 46 ticks examined, 29 (63%) were positive for spotted fever group rickettsiae by detection of the citrate synthase gene by a polymerase chain reaction (pcr). from the positive tick samples, seven were seq ... | 2003 | 14628950 |
| a new focus of rickettsia honei spotted fever in south australia. | we recently diagnosed rickettsial spotted fever in four patients from the south-eastern coastal region of south australia near adelaide, an area not known to be endemic for this infection. all infections were acquired within the geographic range of aponomma hydrosauri, the tick vector of rickettsia honei. infection by r. honei was confirmed in two patients. this extension of the known geographic range of r. honei infection may be explained, in part, by alterations in host-parasite ecology. | 2005 | 15748134 |
| not only 'flinders island' spotted fever. | to demonstrate that flinders island spotted fever (fisf), a spotted fever group rickettsial infection caused by rickettsia honei, is found not only on flinders island (bass strait), tasmania, but elsewhere in south-east australia. | 2005 | 16175900 |
| human infection with rickettsia honei, thailand. | human spotted fever rickettsiosis was detected molecularly by 2 real-time polymerase chain reaction (pcr) assays performed on dna extracted from a thai patient's serum sample. sequences of pcr amplicons from 5 rickettsial genes used for multilocus sequence typing were 100% identical with those deposited with genbank for rickettsia honei tt-118. | 2005 | 16229787 |
| evidence of a spotted fever-like rickettsia and a potential new vector from northeastern australia. | a spotted fever-like rickettsia was identified in a hemaphysalis tick by polymerase chain reaction (pcr) amplification and sequencing of the 16s rdna, ompa, and ompb genes. a comparison of these nucleotide sequences with those of other spotted fever group (sfg) rickettsiae revealed that the hemaphysalis tick rickettsia ia was distinct from other previously reported strains. phylogenetic analysis based on both ompa and ompb also indicates that the strain's closest relatives are the agents of thai ... | 2005 | 16363177 |
| survey of rickettsial antibodies at two local sites and review of rickettsiosis in papua new guinea. | the status of rickettsial infection in papua new guinea (png) is unknown although several reports of typhus-like illnesses infecting predominantly white settlers and the allied troops during world war 2 were published between 1930 and 1945. we performed a serological survey for evidence of rickettsial infection by measuring rickettsia-specific antibody levels in the blood of 191 non-randomly selected papua new guineans living in port moresby (n=93) and in the highland villages of samberigi (n=98 ... | 2003 | 16450784 |
| detection of spotted fever group (sfg) rickettsiae in dermacentor reticulatus (acari: ixodidae) in poland. | dermacentor reticulatus ticks from poland were investigated by molecular methods for the presence of rickettsiae. during 2003/2004, a total of 285 adult ticks was assayed using primers rpcs.877 and rpcs.1258 derived from the citrate synthase (glta) gene, and 116 samples (40.7%) were positive for rickettsial dna. ten out of these positive samples were further assayed using slo1f and slo1r primers derived form the rompa-encoding gene to confirm that detected rickettsiae belong to the spotted fever ... | 2006 | 16524778 |
| flinders island spotted fever rickettsioses caused by "marmionii" strain of rickettsia honei, eastern australia. | australia has 4 rickettsial diseases: murine typhus, queensland tick typhus, flinders island spotted fever, and scrub typhus. we describe 7 cases of a rickettsiosis with an acute onset and symptoms of fever (100%), headache (71%), arthralgia (43%), myalgia (43%), cough (43%), maculopapular/petechial rash (43%), nausea (29%), pharyngitis (29%), lymphadenopathy (29%), and eschar (29%). cases were most prevalent in autumn and from eastern australia, including queensland, tasmania, and south austral ... | 2007 | 17553271 |
| three rickettsioses, darnley island, australia. | we report 3 rickettsioses on darnley island, australia, in the torres strait. in addition to previously described cases of flinders island spotted fever (rickettsia honei strain "marmionii"), we describe 1 case of queensland tick typhus (r. australis) and 2 cases of scrub typhus caused by a unique strain (orientia tsutsugamushi). | 2007 | 18214193 |
| markers of exposure to spotted fever rickettsiae in patients with chronic illness, including fatigue, in two australian populations. | some investigators believe that a proportion of chronically unwell patients, many with fatigue, have an underlying rickettsial disease. | 2008 | 18287113 |
| Rickettsia honei infection in human, Nepal, 2009. | We report a case of Rickettsia honei infection in a human in Nepal. The patient had severe illness and many clinical features typical of Flinders Island spotted fever. Diagnosis was confirmed by indirect immunofluorescent assay with serum and molecular biological techniques. Flinders Island spotted fever may be an endemic rickettsiosis in Nepal. | 2011 | 22000356 |
| widespread use of real-time pcr for rickettsial diagnosis. | we report 2 years of experience with rickettsial molecular diagnosis using real-time pcr at the french national reference center. all rickettsia genomes available were compared to discover specific sequences to design new sets of primers and probes. the specificity was verified in silico and against a panel of 30 rickettsial species. sensitivity was determined using 10-fold serial dilutions. finally, primers and probes that were both specific and sensitive were routinely used for the diagnosis o ... | 2011 | 22092999 |
| rickettsia detected in the reptile tick bothriocroton hydrosauri from the lizard tiliqua rugosa in south australia. | rickettsiosis is a potentially fatal tick borne disease. it is caused by the obligate intracellular bacteria rickettsia, which is transferred to humans through salivary excretions of ticks during the biting process. globally, the incidence of tick-borne diseases is increasing; as such, there is a need for a greater understanding of tick-host interactions to create more informed risk management strategies. flinders island spotted fever rickettsioses has been identified throughout australia (tasma ... | 2016 | 27338482 |
| rickettsial infections in southeast asia: implications for local populace and febrile returned travelers. | rickettsial infections represent a major cause of non-malarial febrile illnesses among the residents of southeast asia and returned travelers from that region. there are several challenges in recognition, diagnosis, and management of rickettsioses endemic to southeast asia. this review focuses on the prevalent rickettsial infections, namely, murine typhus (rickettsia typhi), scrub typhus (orientia tsutsugamushi), and members of spotted fever group rickettsiae. information on epidemiology and reg ... | 2014 | 24957537 |
| genomic comparison of rickettsia honei strain rbt and other rickettsia species. | rickettsia honei strain rb(t) was isolated from a febrile patient on flinders island, australia, in 1991 and has been demonstrated to be the agent of flinders island spotted fever, a disease transmitted to humans by ticks. the comparison of this 1.27-mb genome with other rickettsia genomes provides additional insight into the mechanisms of evolution in rickettsia species. | 0 | 22815457 |
| actin assessment in addition to specific immuno-fluorescence staining to demonstrate rickettsial growth in cell culture. | rickettsiae are able to spread within infected cell mono-layers by modifying intra-cellular actin formations. the study analyzes whether a visualization of actin modifications in addition to specific immuno-fluorescence staining of rickettsiae might facilitate the proof of rickettsial growth in cell culture. cell mono-layers of vero e6 und bgm cells were infected with rickettsia honei. intra-cellular actin was fluorescence stained with tritc-(tetra-methyl-5,6-isothiocyanate)-labeled phalloidin i ... | 2013 | 24265939 |
| identification of rickettsiae from wild rats and cat fleas in malaysia. | rickettsioses are emerging zoonotic diseases reported worldwide. in spite of the serological evidence of spotted fever group rickettsioses in febrile patients in malaysia, limited studies have been conducted to identify the animal reservoirs and vectors of rickettsioses. this study investigated the presence of rickettsiae in the tissue homogenates of 95 wild rats and 589 animal ectoparasites. using pcr assays targeting the citrate synthase gene (glta), rickettsial dna was detected in the tissue ... | 2014 | 25171613 |
| comparison of different media for preservation and transport of viable rickettsiae. | rickettsiae tend to have a rapid decrease of viability outside living cells. therefore, the transport of samples containing viable rickettsiae for culturing in cell culture for diagnostic purposes is challenging. the viability of rickettsiae in different transport media (commercially available transport medium copan "utm-rt transport medium for viruses, chlamydia, mycoplasma, and ureaplasma," minimal essential medium (mem) with and without 10% foetal calf serum) at various time points at 4 °c an ... | 2013 | 24265938 |
| inactivation of rickettsiae. | a reliable and complete inactivation is an indispensable premise for any concentration of rickettsiae or for the development of diagnostic strategies based on their antigens. this study deals with the testing of methods to inactivate rickettsiae. rickettsia honei was used as a model organism. the inactivating potency of formalin, qiagen® antiviral lysozyme (avl) buffer, heating to 56 °c, and β-propiolactone was analyzed in cell culture. the inactivation limits for rickettsiae were 0.1% formalin ... | 2013 | 24265937 |