| platelet-associated immunoglobulin (antiplatelet antibody) in canine rocky mountain spotted fever and ehrlichiosis. | antiplatelet antibodies were detected in the sera of dogs with naturally occurring and experimentally induced rickettsia rickettsii and ehrlichia canis infections. this is the first known report documenting elevated platelet-associated immunoglobulin (paig) titers in rocky mountain spotted fever (rmsf) infections. in the naturally occurring rmsf infections and ehrlichiosis, the antibodies persisted for weeks or months, even when the platelet counts had normalized. results of this study indicate ... | 1999 | 9934930 |
| serologic testing for human granulocytic ehrlichiosis at a national referral center. | an indirect immunofluorescence assay (ifa) was used to identify patients with antibodies reactive to the human granulocytic ehrlichiosis (hge) agent. serum samples collected from clinically ill individuals were submitted to the centers for disease control and prevention by physicians via state health departments from throughout the united states and tested against a panel of ehrlichial and rickettsial pathogens. antibodies reactive to the hge agent were detected in 142 (8.9%) of 1,602 individual ... | 1999 | 9986812 |
| human granulocytic ehrlichiosis in bulgaria. | human granulocytic ehrlichiosis (hge) is a recently described rickettsiosis in the united states transmitted by ixodes species ticks. in europe, only a few studies on hge exist. two hundred bulgarian patients with tick bites and 70 healthy blood donors were tested for hge using an immunofluorescence assay with the hge agent as an antigen. elevated antibody titers (> or = 1:80) were found in 14 (9.7 %) of 145 patients with erythema migrans, two (8%) of 25 tick-exposed patients with lymphadenopath ... | 1999 | 9988323 |
| detection of the agents of human ehrlichioses in ixodid ticks from california. | a study was conducted in northern california to estimate the prevalence and distribution in ixodid ticks of the rickettsial agents of human monocytic (hme) and human granulocytic (hge) ehrlichioses. more than 650 ixodid ticks were collected from 17 sites in six california counties over a 15-month period. ehrlichia chaffeensis, the causative agent of hme, was detected by a nested polymerase chain reaction (pcr) in ixodes pacificus (minimum infection rate [mir] = 13.3%) and dermacentor variabilis ... | 1999 | 9988324 |
| characterization of variable immunodominant antigens of cowdria ruminantium by elisa and immunoblots. | cross-immunization experiments have revealed a significant antigenic diversity of the isolate of cowdria ruminantium which needs to be characterized for the development of vaccines. we identified polymorphic immunodominant antigens by elisa and immunoblot. using serum from a goat immune to the gardel stock of cowdria (isolated in guadeloupe) adsorbed on antigen of the senegal stock of this pathogen, distinct serogroups were revealed by elisa among six isolates from different geographical origins ... | 1998 | 9990646 |
| human granulocytic ehrlichiosis agent and ehrlichia chaffeensis reside in different cytoplasmic compartments in hl-60 cells. | the human granulocytic ehrlichiosis (hge) agent resides and multiplies exclusively in cytoplasmic vacuoles of granulocytes. double immunofluorescence labeling was used to characterize the nature of the hge agent replicative inclusions and to compare them with inclusions containing the human monocytic ehrlichia, ehrlichia chaffeensis, in hl-60 cells. although both ehrlichia spp. can coinfect hl-60 cells, they resided in separate inclusions. inclusions of both ehrlichia spp. were not labeled with ... | 1999 | 10024584 |
| ehrlichia chaffeensis--associated cardiomyopathy in a patient with aids. | | 1999 | 10028085 |
| distributions of the vectors of heartwater, amblyomma hebraeum and amblyomma variegatum (acari: ixodidae), in zimbabwe. | the tick vectors of heartwater (cowdria ruminantium infection) in zimbabwe, amblyomma hebraeum and amblyomma variegatum, historically were believed to be confined to the low-lying regions of the south and north-west of the country. however, country-wide surveys performed in 1975-1980 and 1988-1991 demonstrated that both species were also established in western parts of the highveld plateau and had started to encroach on the predominantly heartwater-free central and eastern highveld regions. to d ... | 1998 | 10030008 |
| 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 |
| dual infection with ehrlichia chaffeensis and a spotted fever group rickettsia: a case report¯reply to dr. sulzer. | | 1998 | 10036225 |
| human ehrlichiosis in central europe. | ehrlichioses are tick-transmitted diseases associated with illnesses of animals for decades, but recently recognised to be emerging human diseases. in the last ten years increasing number of cases of human infections caused by ehrlichia chaffeensis and granulo-cytic ehrlichia were described in the united states. several reports also indicate the presence of infection with the human granulocytic ehrlichiosis (hge) agent in europe. the first confirmed acute human disease caused by hge agent was re ... | 1998 | 10048172 |
| 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 diverse habitats of obligate intracellular parasites. | bacterial obligate intracellular parasites have evolved diverse mechanisms for evasion of host cellular defenses. these mechanisms involve adaptations for survival in distinct intracellular compartments. intracellular niches inhabited by obligate intracellular parasites include the cytoplasm, arrested early endosomes, lysosomes, and vesicles that do not fuse with the endosomal compartment but intersect with an exocytic pathway. | 1998 | 10066459 |
| potential value of major antigenic protein 2 for serological diagnosis of heartwater and related ehrlichial infections. | cowdria ruminantium is the etiologic agent of heartwater, a disease causing major economic loss in ruminants in sub-saharan africa and the caribbean. development of a serodiagnostic test is essential for determining the carrier status of animals from regions where heartwater is endemic, but most available tests give false-positive reactions with sera against related erhlichia species. current approaches rely on molecular methods to define proteins and epitopes that may allow specific diagnosis. ... | 1999 | 10066656 |
| monocytic ehrlichia in ixodes persulcatus ticks from perm, russia. | | 1999 | 10073519 |
| comparison of ehrlichia muris strains isolated from wild mice and ticks and serologic survey of humans and animals with e. muris as antigen. | in metropolitan tokyo, the ehrlichia muris seropositivity rate of 24 wild mice was 63% in hinohara village, but in the surrounding areas, it was 0 to 5%. this finding suggests that the reservoir of e. muris is focal. among the 15 seropositive mice, ehrlichiae were isolated from 9 apodemus speciosus mice and 1 a. argenteus mouse, respectively. five ehrlichial isolates were obtained from 10 ticks (haemaphysalis flava) collected in asuke town, aichi prefecture, where the e. muris type strain had be ... | 1999 | 10074536 |
| genetic diversity of the 28-kilodalton outer membrane protein gene in human isolates of ehrlichia chaffeensis. | the ehrlichia chaffeensis 28-kda outer membrane protein (p28) gene was sequenced completely by genomic walking with adapter pcr. the dna sequence of the p28 gene was nearly identical to the previously reported sequence (n. ohashi, n. zhi, y. zhang, and y. rikihisa, infect. immun. 66:132-139, 1998), but analysis of a further 75 bp on the 5' end of the gene revealed dna that encoded a 25-amino-acid signal sequence. the leader sequence was removed from the n terminus of a 30-kda precursor to genera ... | 1999 | 10074538 |
| 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 |
| granulocyte function in dogs experimentally infected with a swedish granulocytic ehrlichia species. | granulocyte function was studied in six dogs inoculated with a swedish granulocytic ehrlichia species and in four control dogs. whole blood chemiluminescence (cl) was enhanced in the dogs with granulocytic ehrlichiosis. both cl after stimulation with zymosan and spontaneous cl was significantly increased at peak of infection compared with pre-infection levels. ingestion of fitc-labelled serum-opsonized yeast cells was high and stable in both groups. the ingestion was lower when the yeast cells w ... | 1999 | 10077420 |
| restriction of major surface protein 2 (msp2) variants during tick transmission of the ehrlichia anaplasma marginale. | anaplasma marginale is an ehrlichial pathogen of cattle that establishes lifelong persistent infection. persistence is characterized by rickettsemic cycles in which new a. marginale variant types, defined by the sequence of the expressed msp2 transcripts, emerge. the polymorphic msp2 transcripts encode structurally distinct msp2 proteins and result in an antigenically diverse and continually changing a. marginale population within the blood. in this manuscript, we used sequence analysis of msp2 ... | 1999 | 10077656 |
| novel ehrlichia organism (rickettsiales: ehrlichieae) in white-tailed deer associated with lone star tick (acari: ixodidae) parasitism. | polymerase chain reaction (pcr) evidence of a novel ehrlichia organism was found recently in wild white-tailed deer, odocoileus virginianus zimmermann, and lone star ticks, amblyomma americanum l., from the southeastern united states. to evaluate whether lone star tick parasitism was associated with the presence of this novel ehrlichia organism in deer, 2 retrospective studies were conducted using specific nested pcr to test archived deer serum samples. the 1st study of 150 serum samples collect ... | 1999 | 10083757 |
| [ehrlichiosis]. | | 1999 | 10088349 |
| feline granulocytic ehrlichiosis--a report of a new clinical entity and characterisation of the infectious agent. | a 14-month-old shorthaired cat was presented to the animal hospital in skara, sweden, with a two-day history of lethargy, anorexia and tachypnoea. clinical examination and laboratory investigations revealed fever, dehydration, tick infestation, neutrophilia with left shift, lymphopenia, hyperglycaemia and intracytoplasmic neutrophilic ehrlichia inclusions. after treatment with intravenous doxycycline and lactated ringer's solution the temperature returned to normal. oral treatment with doxycycli ... | 1999 | 10092038 |
| disease-specific pathology in neurons cultured from sheep affected with ceroid lipofuscinosis. | the neuronal ceroid lipofuscinoses (ncl, batten disease) are a group of inherited neurodegenerative storage diseases in children. mutations in different genes underlie different forms. subunit c of mitochondrial atp synthase is specifically stored in autofluorescent bodies in most of them, including a form in sheep. mature bodies are lysosomal but the initial site of storage is not known, nor is it known how this leads to the characteristic neurodegeneration. neurons were cultured in serum-free ... | 1999 | 10191133 |
| serological survey for antibodies reactive with ehrlichia canis and e. chaffeensis in dogs from the bloemfontein area, south africa. | sera from 161 dogs in the bloemfontein area in south africa were tested for the presence of antibodies reactive with ehrlichia canis and e. chaffeensis by indirect fluorescent antibody testing. overall, 68 (42%) of the dogs had significant antibody titres (> or = 1/64) against e. canis and 61 (38%) had significant titres (> or = 1/64) against e. chaffeensis. seven (11%) dogs had higher titres to e. chaffeensis than e. canis (1/2048 and 1/1024 (2 dogs); 1/1024 and 1/512 (2 dogs); 1/2048 and 1/512 ... | 1998 | 10192085 |
| models for heartwater epidemiology: practical implications and suggestions for future research. | we present a simple model of the dynamics of heartwater that we use to explore and better understand various aspects of this disease. we adapted the ross-macdonald model for malaria epidemiology so that we could consider both host and vector populations, and evaluate the interactions between the two. we then use two more biologically detailed models to examine heartwater epidemiology. the first includes a carrier state and host mortality, and the second includes density dependence. the results f ... | 1998 | 10192838 |
| the map1 gene of cowdria ruminantium is a member of a multigene family containing both conserved and variable genes. | heartwater is an economically important disease of ruminants caused by the tick-transmitted rickettsia cowdria ruminantium. the disease is present in africa and the caribbean and there is a risk of spread to the americas, particularly because of a clinically asymptomatic carrier state in infected livestock and imported wild animals. the causative agent is closely related taxonomically to the human and animal pathogens ehrlichia chaffeensis and ehrlichia canis. a dominant immune response of infec ... | 1999 | 10198207 |
| [sennetsu rickettsiosis]. | | 1999 | 10201200 |
| 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 |
| molecular cloning and characterization of the ehrlichia chaffeensis variable-length pcr target: an antigen-expressing gene that exhibits interstrain variation. | a clone expressing an immunoreactive protein with an apparent molecular mass of 44 kda was selected from an ehrlichia chaffeensis arkansas genomic library by probing with anti-e. chaffeensis hyperimmune mouse ascitic fluid. nucleotide sequencing revealed an open reading frame (orf) capable of encoding a 198-amino-acid polypeptide. the orf contained four imperfect, direct, tandem 90-bp repeats. the nucleotide and deduced amino acid sequences did not show close homologies to entries in the molecul ... | 1999 | 10203503 |
| human granulocytic ehrlichiosis in western europe. | | 1999 | 10206853 |
| inhibition of phagosome-lysosome fusion in ovine polymorphonuclear leucocytes by ehrlichia (cytoecetes) phagocytophila. | ehrlichia (cytoecetes) phagocytophila, the causative agent of tick-borne fever, is an intracellular bacterium that survives and multiplies within granulocytes and monocytes. in the present study, the possible fusion of lysosomes with phagosomes containing e. phagocytophila was investigated in poly-morphonuclear (pmn) cells of sheep infected with the agent, acid phosphatase cytochemistry and cationized ferritin being used as markers of primary and secondary lysosomal enzymes. latex beads or candi ... | 1999 | 10208733 |
| 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 |
| differential haematological effects of tick-borne fever in sheep and goats. | tick-borne fever (tbf) is a rickettsial disease of domestic and wild ruminants in temperate climates. it is characterized by high fever and severe leukopenia. in the present study, the possible difference in the severity of disease in sheep and goats was investigated by inoculating one group of eight goats and one group of eight sheep with the old sourhope (os) strain of ehrlichia (cytoecetes) phagocytophila. all sheep and goats experimentally infected with e. phagocytophila reacted with fever a ... | 1999 | 10216453 |
| disparity in the natural cycles of borrelia burgdorferi and the agent of human granulocytic ehrlichiosis. | we studied the prevalence of borrelia burgdorferi and the agent of human granulocytic ehrlichiosis (hge) among questing nymphal and adult ixodes scapularis ticks of the same generation and the infectivity of wild white-footed mice for ticks feeding on them. the prevalence of b. burgdorferi infection in host-seeking ticks increased less than twofold from nymphal (31% to 33%) to adult (52% to 56%) stage, and 52% of white-footed mice were infected. prevalence of the agent of hge increased 4.5- to 1 ... | 1999 | 10221871 |
| seroprevalence and seroconversion for tick-borne diseases in a high-risk population in the northeast united states. | to determine the prevalence of serologic reactivity, the 1-year incidence of seroconversion, and the frequency of multiple infections, and their associations with symptoms in a group of volunteers at high risk for tick-borne infections in new york state. | 1999 | 10225242 |
| molecular cloning of the gene for a conserved major immunoreactive 28-kilodalton protein of ehrlichia canis: a potential serodiagnostic antigen. | a gene encoding a 28-kda protein of ehrlichia canis was cloned, sequenced, and expressed, and a comparative molecular analysis with homologous genes of e. canis, cowdria ruminantium, and ehrlichia chaffeensis was performed. the complete gene has an 834-bp open reading frame encoding a protein of 278 amino acids with a predicted molecular mass of 30.5 kda. an n-terminal signal sequence was identified, suggesting that the protein undergoes posttranslational modification to a mature 27.7-kda protei ... | 1999 | 10225842 |
| ehrlichia chaffeensis and e. sennetsu, but not the human granulocytic ehrlichiosis agent, colocalize with transferrin receptor and up-regulate transferrin receptor mrna by activating iron-responsive protein 1. | ehrlichia chaffeensis and e. sennetsu are genetically divergent obligatory intracellular bacteria of human monocytes and macrophages, and the human granulocytic ehrlichiosis (hge) agent is an obligatory intracellular bacterium of granulocytes. infection with both e. chaffeensis and e. sennetsu, but not hge agent, in the acute monocytic leukemia cell line thp-1 almost completely inhibited by treatment with deferoxamine, a cell-permeable iron chelator. transferrin receptors (tfrs) accumulated on b ... | 1999 | 10225882 |
| cross-reactive epitope mimics in a fragmented-genome phage display library derived from the rickettsia, cowdria ruminantium. | epitopes can be mapped by comparing immunoaffinity-selected peptides from fragmented-gene display libraries with the target gene. with larger libraries derived from unsequenced genomes, this is not possible. spurious epitope mimics may be created by expressing dna in a variety of meaningless reading frames and orientations. | 1999 | 10231087 |
| antibodies to granulocytic ehrlichiae in white-footed and cotton mice in eastern united states. | serum samples, collected from peromyscus leucopus (white-footed mouse) or peromyscus gossypinus (cotton mouse) during 1987 through 1990 in florida, georgia, maryland, mississippi, and north carolina (usa), and in 1997 in southern connecticut were analyzed by indirect fluorescent antibody (ifa) staining methods or western blot procedures for antibodies to granulocytic ehrlichiae. of the 82 sera from white-footed mice in connecticut tested by ifa methods with either the bds or nch-1 strain of the ... | 1999 | 10231752 |
| infections of granulocytic ehrlichiae and borrelia burgdorferi in white-tailed deer in connecticut. | serum or whole blood samples, obtained from 141 white-tailed deer (odocoileus virginianus) in connecticut (usa) during 1980, 1991, and 1996, were analyzed to detect past or current infections of ehrlichia phagocytophila genogroup organisms and borrelia burgdorferi. when the bds or nch-1 strains of granulocytic ehrlichiae were used separately in indirect fluorescent antibody (ifa) staining methods, antibody positivity rates varied from 25 to 64% in 1991 and 1996, respectively. all 50 sera tested ... | 1999 | 10231753 |
| antibodies reactive with ehrlichia canis, ehrlichia phagocytophila genogroup antigens and the spotted fever group rickettsial antigens, in free-ranging jackals (canis aureus syriacus) from israel. | a seroepidemiological survey was conducted to investigate the prevalence of antibodies reactive with the ehrlichia canis and ehrlichia phagocytophila genogroup antigens, and the spotted fever group (sfg) rickettsiae antigens in jackals in israel (canis aureus syriacus), to assess the possible role of the jackal in the epidemiology of these diseases. fifty-three serum samples from jackals were assayed by the indirect immunofluorescence antibody test. antibodies to e. canis were detected in 35.8% ... | 1999 | 10321583 |
| 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 |
| infection of laboratory mice with the human granulocytic ehrlichiosis agent does not induce antibodies to diagnostically significant borrelia burgdorferi antigens. | laboratory diagnosis of borrelia burgdorferi is routinely made by an enzyme-linked immunosorbent assay, with positive results confirmed by western blot analysis. concern has been raised that false-positive diagnoses may be made on the basis of serologic cross-reactivity with antibodies directed against other bacterial pathogens, in particular the agent of human granulocytic ehrlichiosis (hge). the present study made use of a mouse model to ascertain the validity of these concerns. two different ... | 1999 | 10325386 |
| an assessment of the economic impact of heartwater (cowdria ruminantium infection) and its control in zimbabwe. | heartwater, caused by the rickettsial organism cowdria ruminantium, is a serious constraint to livestock development in much of sub-saharan africa. traditionally, the disease has been controlled by the use of chemical acaricides to control the vector tick. the university of florida/usaid-supported heartwater research project (based in zimbabwe) is developing a new inactivated vaccine to control the disease. in order that the vaccine is used effectively, the project has been studying the epidemio ... | 1999 | 10327437 |
| the control of heartwater on large-scale commercial and smallholder farms in zimbabwe. | as part of a series of studies associated with the development of improved vaccines for heartwater (a tick-borne disease of ruminant livestock caused by cowdria ruminantium), field surveys were carried out to assess losses associated with the disease and the costs associated with controlling it in the two main agro-ecological zones of zimbabwe (lowveld and highveld) where heartwater is believed to be endemic and epidemic, respectively. in each zone, a cross-sectional study was performed in the m ... | 1999 | 10327438 |
| serologic testing of horses for granulocytic ehrlichiosis, using indirect fluorescent antibody staining and immunoblot analysis. | to diagnose granulocytic ehrlichiosis in horses, compare results of indirect fluorescent antibody (ifa) staining procedures with those of immunoblot analysis, and compare serologic test findings with polymerase chain reaction (pcr) results. | 1999 | 10328436 |
| evaluation of an improved pcr diagnostic assay for human granulocytic ehrlichiosis. | background: human granulocytic ehrlichiosis (hge) is a tick-borne disease caused by an agent similar to ehrlichia equi. the etiologic agent has only recently been cultivated, and clinical and laboratory findings are nonspecific. severity and fatal outcome are associated with delays in diagnosis and therapy. methods and results: the sensitivity of the polymerase chain reaction (pcr) technique for hge was enhanced at least 250-fold for identification of the 16s ribosomal rna gene of the hge agent ... | 1996 | 10330196 |
| [ehrlichiosis: a tick-born infection]. | ehrlichiosis is the potentially life-threating infection. it is caused by obligate intracellular bacteria. the clinical presentations are fever, headache, myalgia, malaise, nausea, vomiting and other nonspecyfic symptoms. some patients develop neurologic symptoms and signs. the are two distinct forms of human ehrlichiosis: human monocytic ehrlichiosis /hme/--cased by ehrlichia chaffeensis that infects mononuclear phagocytes and human granulocytic ehrlichiosis /hge/--caused by e. species closely ... | 1999 | 10337186 |
| first case of human ehrlichiosis in mexico. | | 1999 | 10341193 |
| adaptation of the agent of the human monocyte ehrlichiosis (ehrlichia chaffeensis) to hl60. | | 1999 | 10348219 |
| evaluation of 16s, map1 and pcs20 probes for detection of cowdria and ehrlichia species. | a panel of 16s ribosomal rna gene probes has been developed for the study of the epidemiology of heartwater; five of these detect different cowdria genotypes, one detects five distinct genotypes; one detects any group iii ehrlichia species other than cowdria and one detects any group ii ehrlichia species. these probes have been used on pcr-amplified rickettsial 16s rrna genes from over 200 amblyomma hebraeum ticks. control ticks were laboratory-reared and either uninfected or fed on sheep experi ... | 1999 | 10355799 |
| prevalence of antibodies against the human granulocytic ehrlichiosis agent in lyme borreliosis patients from germany. | to contribute to the discussion of whether or not human granulocytic ehrlichiosis (hge) occurs in midwestern germany, sera from individuals with different risk categories for tick exposure were retrospectively examined by means of an immunofluorescence assay. the seroreprevalence for the hge agent accounted for 5.5% of the 270 patients tested. specific antibodies were detected more often in patients with early lyme infection than in patients with stage iii disease or in asymptomatic individuals ... | 1999 | 10357060 |
| a retrospective study of ehrlichiosis in 62 dogs from north carolina and virginia. | the purpose of this retrospective study is to report the clinical signs, clinicopathological findings, and response to therapy of 62 dogs from north carolina and virginia. ehrlichiosis was diagnosed in all of these dogs, and previous retrospective studies of ehrlichiosis in dogs were used as a basis for comparison. in this study, the clinical signs commonly associated with ehrlichiosis were observed less frequently than in earlier studies, although previously reported laboratory abnormalities we ... | 1999 | 10357108 |
| clinical and laboratory evolution of a culture-confirmed case of human granulocytic ehrlichiosis. | a 74-year-old man from suburban new york city, who was hospitalized because of chest pain and fever, was diagnosed as having human granulocytic ehrlichiosis on the eighth hospital day. although leukocyte and platelet counts were normal on admission, they fell to abnormally low values then normalized prior to specific therapy against the human granulocytic ehrlichiosis agent. intracytoplasmic inclusions suggestive of ehrlichia were observed in up to six percent of granulocytes, and the human gran ... | 1999 | 10363404 |
| multiple p44 genes encoding major outer membrane proteins are expressed in the human granulocytic ehrlichiosis agent. | human granulocytic ehrlichiosis (hge) is caused by infection with an obligatory intracellular bacterium, the hge agent. we previously cloned a gene encoding hge agent 44-kda major outer membrane protein and designated it p44. in this study, we (i) identified five different mrnas that are transcribed from p44-homologous genes in the hge agent cultivated in hl-60 cells; (ii) cloned genes corresponding to the mrnas from the genomic dna of the hge agent; (iii) showed that the genes being expressed w ... | 1999 | 10364227 |
| 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 |
| immune responses to cowdria ruminantium infections. | understanding the basis of protective immunity to cowdria ruminantium will facilitate the development of an effective subunit vaccine against heartwater in ruminants and contribute to a better definition of protective immune mechanisms to obligate intracellular pathogens in general. until recently, immunological studies of heartwater in ruminants concentrated solely on antibody responses. since 1995, the mechanisms underlying cell-mediated immunity of heartwater have been analysed. progress achi ... | 1999 | 10377532 |
| vaccine strategies for cowdria ruminantium infections and their application to other ehrlichial infections. | suman mahan and co-authors review the strategies applied to develop improved vaccines for cowdria ruminantium infections (heartwater). inactivated vaccines using cell-cultured c. ruminantium organisms combined with an adjuvant are capable of protecting goats, sheep and cattle against lethal c. ruminantium challenge. immune responses induced with this vaccine, or after recovery from infection, target outer membrane proteins of c. ruminantium, in particular the major antigenic protein 1 (map-1). g ... | 1999 | 10377533 |
| serological evidence of ehrlichia infection in swedish lyme borreliosis patients. | we studied sera from patients who had participated in a prospective study of borreliosis in sweden and had acquired tick bites in areas of the country with a high prevalence of granulocytic ehrlichial infections in animals. the sera were examined for igg anti ehrlichia antibodies by an indirect immunofluorescence assay using a locally isolated bovine ehrlichia antigen. confirmation of the serological results was done at the unité des rickettsies, marseille, france. three out of 37 of the investi ... | 1999 | 10381218 |
| susceptibility and carrier status of impala, sable, and tsessebe for cowdria ruminantium infection (heartwater). | three species of wild african ruminants, impala (aepyceros melampus), sable (hippotragus equinus), and tsessebe (damaliscus lunatus), were experimentally inoculated with in vitro culture-derived cowdria ruminantium organisms, the tick-borne causative agent of heartwater in domestic ruminants, to determine their susceptibility to infection. no clinical disease was observed in any of the ruminants. however, c. ruminantium was detected in the sable by the transmission of heartwater to susceptible s ... | 1999 | 10386439 |
| ehrlichial meningitis with cerebrospinal fluid morulae. | | 1999 | 10391189 |
| lymphocyte responses to mitogens and rickettsial antigens in sheep experimentally infected with ehrlichia (cytoecetes) phagocytophila. | infection of sheep with ehrlichia (cytoecetes) phagocytophila, the causative agent of tick-borne fever (tbf), was characterised by a significant reduction in lymphocyte reactivity to the mitogens phytohaemagglutinin, concanavalin a, pokeweed mitogen and escherichia coli lipopolysaccharide during the period of rickettsiaemia. the addition of the prostaglandin inhibitor, indomethacin, or the nitric oxide inhibitor, n(g)-monomethyl-l-arginine, had no significant effect on the suppressive effects of ... | 1999 | 10392768 |
| development and distribution of pathologic lesions are related to immune status and tissue deposition of human granulocytic ehrlichiosis agent-infected cells in a murine model system. | to evaluate pathology and the role of immune status in a murine model system of human granulocytic ehrlichiosis (hge), c3h/hej, c3h-scid, and peromyscus leucopus mice were infected with an hge agent. all mice remained healthy. ehrlichemia was not detected after day 14 in p. leucopus and c3h/hej mice but increased between days 14 and 90 in c3h-scid mice. in tissues examined at day 21 and later, infection was rarely detected in immunocompetent mice but was present in all c3h-scid mice and included ... | 1999 | 10395880 |
| electron microscopy of cowdria-infected macrophages suggests that in the absence of binary fission a mosaic of organisms develops from an amorphous electron dense matrix. | electron microscopy of mouse peritoneal macrophages infected with the kümm stock of cowdria ruminantium suggests that in the final stage of intracellular growth, a mosaic of organisms develops from an amorphous matrix of varying electron density by a process in which double unit membranes portion off the cowdria particles. this stage is preceded by inclusions consisting of a network of aggregated electron dense granules and these in turn by homogeneous dense bodies. the study failed to show how ... | 1999 | 10396761 |
| a simian model of human granulocytic ehrlichiosis. | following intravenous inoculation with horse blood-infected with the agent of human granulocytic ehrlichiosis (hge) from a human fatality, two rhesus macaques (macaca mulatta) exhibited pyrexia and lethargy on days 4-12 postinfection (pi). hematology revealed neutropenia, thrombocytopenia, and anemia, with ehrlichial morulae in monocytes and neutrophils on days 4-12. blood was polymerase chain reaction (pcr)-positive on days 4-12 and bone marrow was pcr-positive on day 11. there was a minor incr ... | 1999 | 10403332 |
| ehrlichia ewingii, a newly recognized agent of human ehrlichiosis. | human ehrlichiosis is a recently recognized tick-borne infection. four species infect humans: ehrlichia chaffeensis, e. sennetsu, e. canis, and the agent of human granulocytic ehrlichiosis. | 1999 | 10403852 |
| ehrlichiosis--ticks, dogs, and doxycycline. | | 1999 | 10403860 |
| 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 |
| comparison of ehrlichia chaffeensis recombinant proteins for serologic diagnosis of human monocytotropic ehrlichiosis. | diagnosis of human monocytotropic ehrlichiosis (hme) generally depends on serology that detects the antibody response to immunodominant proteins of ehrlichia chaffeensis. protein immunoblotting was used to evaluate the reaction of the antibodies in patients' sera with the recombinant e. chaffeensis 120- and 28-kda proteins as well as the 106- and the 37-kda proteins. the cloning of the genes encoding the latter two proteins is described in this report. immunoelectron microscopy demonstrated that ... | 1999 | 10405403 |
| coinfection with multiple tick-borne pathogens in a walker hound kennel in north carolina. | both dogs and humans can be coinfected with various ehrlichia, bartonella, rickettsia, and babesia species. we investigated a kennel of sick walker hounds and their owners in southeastern north carolina for evidence of tick-borne infections and associated risk factors. a high degree of coinfection was documented in the dog population. of the 27 dogs, 26 were seroreactive to an ehrlichia sp., 16 to babesia canis, and 25 to bartonella vinsonii, and 22 seroconverted to rickettsia rickettsii antigen ... | 1999 | 10405413 |
| determination of the genome size of ehrlichia spp., using pulsed field gel electrophoresis. | ehrlichiae are obligatory intracellular, gram-negative bacteria which belong to the alpha subclass of the phylum proteobacteria and are responsible for infectious diseases of humans. little is known about genetics and genomic organization of ehrlichia spp. the genome sizes of four representatives of the genus ehrlichia were determined for the first time by pulsed field gel electrophoresis. the sizes for e. sennetsu, e. risticii, e. chaffeensis (strain arkansas and strain 91he17), and the hge age ... | 1999 | 10418133 |
| a further case of acute human granulocytic ehrlichiosis in slovenia. | | 1999 | 10421051 |
| ehrlichia platys infection and disease in dogs in spain. | | 1999 | 10424661 |
| variability in the 28-kda surface antigen protein multigene locus of isolates of the emerging disease agent ehrlichia chaffeensis suggests that it plays a role in immune evasion. | infections caused by rickettsial pathogens persist in vertebrate hosts for long periods of time, despite the active host immune response. we recently described the multigene locus encoding 28 kda surface antigen proteins (28 kda saps) for two closely related rickettsials, ehrlichia chaffeensis and ehrlichia canis (reddy, g. r., et al. (1998) biochem. biophys. res. commun. 247, 636-643), that share extensive structural homology to antigenic variant surface protein genes of neisseria and borrelia ... | 1999 | 10425222 |
| characterization of monoclonal antibodies to an immunodominant protein of the etiologic agent of human granulocytic ehrlichiosis. | immunodominant proteins in the range of 42-45 kd are important for the serodiagnosis of human granulocytic ehrlichiosis (hge). antigens from human isolates of the etiologic agent of hge cultivated in hl-60 cells were used to immunize balb/c mice and generate a panel of hybridomas secreting monoclonal antibodies. using an enzyme immunoassay, an immunofluorescent assay (ifa), and western blotting, we showed that culture supernatants and ascites of these hybridomas were reactive with human isolates ... | 1999 | 10432075 |
| molecular detection of babesia equi and babesia caballi in horse blood by pcr amplification of part of the 16s rrna gene. | babesia equi and babesia caballi are tick-borne haemoparasites that may cause babesiosis of equidae. in southern europe b. equi is enzootic and infections may occur asymptomatically and more frequently than those due to b. caballi. complement fixation test (cft) is the official serological test for the diagnosis of equine babesiosis, but it has low sensitivity during early and latent stages of the disease. with the aim of developing more sensitive and rapid direct diagnostic alternatives, pcr sy ... | 1999 | 10435792 |
| gastrointestinal and hepatic manifestations of human ehrlichiosis: 8 cases and a review of the literature. | ehrlichiosis has emerged as an increasingly recognized tick-borne rickettsial disease. it can affect multiple organs including the gastrointestinal tract and liver. signs and symptoms include abdominal pain, nausea, vomiting, diarrhea, jaundice, and hepatosplenomegaly. patients commonly have elevated liver transaminases early in the course of illness as well as leukopenia and thrombocytopenia. if not diagnosed and treated in a timely fashion, ehrlichiosis can progress to multiorgan failure. | 1999 | 10436355 |
| the incidence of ehrlichial and rickettsial infection in patients with unexplained fever and recent history of tick bite in central north carolina. | we examined the clinical and laboratory findings of a consecutive series of patients from central north carolina presenting with fever and a history of tick bite within the preceding 14 days. evidence of a tick-transmitted pathogen was detected in 16 of 35 patients enrolled over a 2-year period. nine patients were infected with ehrlichia chaffeensis, and 6 were infected with a spotted fever group rickettsia; 1 patient had evidence of coinfection with e. chaffeensis and a spotted fever group rick ... | 1999 | 10438390 |
| quantification of the human granulocytic ehrlichiosis agent based on analysis of rrna isolated from control and infected hl-60 cells. | human granulocytic ehrlichiosis (hge) is an emerging vector-borne disease caused by an ehrlichia species similar or identical to e. equi and e. phagocytophila. previous studies have shown that the pathogen can be cultivated in vitro in permissive cells such as human promyelocytic hl-60 leukemia cells. the mechanism(s) of its infection and propagation in target cells, however, is not well understood, due in part to lack of a method capable of quantitatively determining the amount of the infectiou ... | 1999 | 10448059 |
| the effect of subclinical experimental cowdria ruminantium infection on the health and reproductive performance of breeding ewes. | this study documented the effect on the productivity of dorper-merino cross ewes when they became infected with cowdria ruminantium as would occur in an endemically stable state. a flock of 152 breeding ewes was randomly divided into two matched groups. one group was infected on multiple occasions with c. ruminantium; the other group remained uninfected. the ewes were bred and monitored for one breeding/lambing/weaning cycle. hematological, reproductive, and health parameters were recorded at re ... | 1999 | 10448939 |
| the effect of subclinical experimental cowdria ruminantium infection in ewes on the growth and milk consumption of pre-weaning lambs. | an alternative control option for heartwater (cowdria ruminantium infection) is the establishment and maintenance of endemic stability which would lessen the existing dependence on acaricides. in an endemically stable state, animals become infected by vaccination or natural challenge at an early age, following which the immunity so created is boosted by continuing tick challenge. in this study, growth rates, health and hematological parameters were monitored at regular intervals for lambs born t ... | 1999 | 10448940 |
| infection with agents of human granulocytic ehrlichiosis, lyme disease, and babesiosis in wild white-footed mice (peromyscus leucopus) in connecticut. | white-footed mice, peromyscus leucopus, were captured in southern connecticut during 1997 and 1998 to determine the prevalence of infections caused by granulocytic ehrlichia sp., borrelia burgdorferi, and babesia microti. of the 50 mice captured and recaptured, 25 of 47 (53.2%) and 23 of 48 (47.9%) contained antibodies to the bds or nch-1 ehrlichia strains, respectively, as determined by indirect fluorescent antibody (ifa) staining methods. the majority (83.3%) of 48 mice also contained antibodi ... | 1999 | 10449470 |
| inter- and intralaboratory comparison of ehrlichia equi and human granulocytic ehrlichiosis (hge) agent strains for serodiagnosis of hge by the immunofluorescent-antibody test. | human granulocytic ehrlichiosis (hge) is usually diagnosed by immunofluorescent antibody (ifa) serology with ehrlichia equi-infected neutrophils or hge agent-infected cultured hl60 cells. the hge agent and e. equi are antigenically diverse, and interpretation of serologic results is also often variable. thus, we investigated the sensitivity and specificity of various hge agent and e. equi antigens used for ifa diagnosis by three different laboratories. serum samples from 28 patients with well-ch ... | 1999 | 10449483 |
| outcome of diagnostic tests using samples from patients with culture-proven human monocytic ehrlichiosis: implications for surveillance. | we describe the concordance among results from various laboratory tests using samples derived from nine culture-proven cases of human monocytic ehrlichiosis (hme) caused by ehrlichia chaffeensis. a class-specific indirect immunofluorescence assay for immunoglobulin m (igm) and igg, using e. chaffeensis antigen, identified 44 and 33% of the isolation-confirmed hme patients on the basis of samples obtained at initial clinical presentation, respectively; detection of morulae in blood smears was sim ... | 1999 | 10449489 |
| evidence of rickettsial spotted fever and ehrlichial infections in a subtropical territory of jujuy, argentina. | between november 1993 and march 1994, a cluster 6 pediatric patients with acute febrile illnesses associated with rashes was identified in jujuy province, argentina. immunohistochemical staining of tissues confirmed spotted fever group rickettsial infection in a patient with fatal disease, and testing of serum of a patient convalescing from the illness by using an indirect immunofluorescence assay (ifa) demonstrated antibodies reactive with spotted fever group rickettsiae. a serosurvey was condu ... | 1999 | 10463693 |
| comparison of methods for introducing and producing artificial infection of ixodid ticks (acari: ixodidae) with ehrlichia chaffeensis. | only 29.5 +/- 8.91% of engorged amblyomma americanum (l.) nymphs that we inoculated with ehrlichia chaffeensis molted successfully to adults compared with 75.8 +/- 7.46% of engorged nymphs that were not inoculated. however, 65.4 +/- 6.02% of unfed nymphs of this species were exposed for 2 h to e. chaffeensis suspension introduced to them through glass capillaries gained weight. these nymphs were placed on rabbits, and approximately 50% of them completed their feeding and molted successfully to a ... | 1999 | 10467766 |
| rapidly fatal infection with ehrlichia chaffeensis. | | 1999 | 10475799 |
| shared vector-borne zoonoses of the old world and new world: home grown or translocated? | humans inhabiting the old world and new world share a wide variety of pathogens. processes that result in the disjunct biogeographic distribution of pathogens with common vertebrate reservoirs or vectors are more difficult to unravel than those influencing the distribution of infections spread only through human-to-human transmission. the origins of species and complexes of tick-borne bacteria are unclear. the agent of lyme borreliosis may have speciated in the new world following geographical i ... | 1999 | 10476548 |
| human granulocytic ehrlichiosis in northern california: two case descriptions with genetic analysis of the ehrlichiae. | we report two cases of human granulocytic ehrlichiosis (hge) that occurred in northern california in summer 1998. patients had fever, malaise, and myalgia, reported tick bites, had moderate thrombocytopenia, and had normal or slightly elevated liver enzyme activities. ehrlichial inclusions were observed in the blood of one patient, and hge-agent dna was amplified by pcr from both patients. genetically, the strains resembled horse isolates from northern california. the close spatial and temporal ... | 1999 | 10476747 |
| ehrlichia chaffeensis in archived tissues of a white-tailed deer. | white-tailed deer (odocoileus virginianus) play an integral role in the natural history of ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis (hme). paraffinized tissues from a white-tailed deer submitted as a diagnostic case to the southeastern cooperative wildlife disease study (athens, georgia, usa) in october of 198.5 and originally described as infected with an unidentified rickettsial organisim were re-examined by specific nested polymerase chain reaction (pcr) for ... | 1999 | 10479099 |
| ehrlichia (cytoecetes) phagocytophila predisposes to severe contagious ecthyma (orf ) in lambs. | eight lambs experimentally infected with ehrlichia (cytoecetes) phagocytophila 7 days before exposure to orf virus were compared with control lambs infected with orf virus alone. the dually infected animals differed from the controls in showing skin lesions of greater severity, prolonged viral shedding, and lower antibody titres. infection with e. phagocytophila had no significant effect on virus-specific lymphocyte proliferation. such proliferation was detected in the peripheral blood of all la ... | 1999 | 10486159 |
| cowdria ruminantium dna is unstable in a supercos1 library. | a cowdria ruminantium genomic library was constructed in a cosmid vector to serve as a source of easily accessible and pure c. ruminantium dna for molecular genetic studies. the cosmid library contained 846 clones which were arrayed into microtitre plates. restriction enzyme digestion patterns indicated that these clones had an average insert size of 35 kb. probing of the arrays did not detect any bovine clones and only one of the known c. ruminantium genes, pcs20, was detected. due to the high ... | 1999 | 10486827 |
| dusky-footed wood rats (neotoma fuscipes) as reservoirs of granulocytic ehrlichiae (rickettsiales: ehrlichieae) in northern california. | dusky-footed wood rats (neotoma fuscipes) and peromyscus sp. mice (p. maniculatus and p. truei) were collected from one site in placer county, one site in santa cruz county, and two sites in sonoma county in northern california. serum or plasma samples from 260 rodents were tested for antibodies to the agent of human granulocytic ehrlichiosis. of these, samples from 25 wood rats (34% of those tested) and 10 (8%) peromyscus sp. mice were found to be seropositive, but only those from one site. pcr ... | 1999 | 10488199 |
| molecular evidence of coinfection of ticks with borrelia burgdorferi sensu lato and the human granulocytic ehrlichiosis agent in switzerland. | adult ixodes ricinus ticks were collected in switzerland and tested for the presence of coinfection with borrelia burgdorferi sensu lato and the human granulocytic ehrlichiosis (hge) agent by real-time pcr. of 100 ticks, 49% were positive for b. burgdorferi and 2% were positive for the hge agent. the two hge agent-positive ticks were also found to be positive for b. burgdorferi. | 1999 | 10488215 |
| efficacy of enrofloxacin for the treatment of experimentally induced ehrlichia canis infection. | | 1999 | 10499737 |
| bovine cd4+ t-cells lines reactive with soluble and membrane antigens of cowdria ruminantium. | cowdria-specific cd4+ t-cell lines generated from immunised cattle respond to both soluble and membrane proteins of the agent. furthermore, the lines produced the cowdria-inhibitory cytokine ifn-gamma in response to soluble antigens fractionated by gel filtration and fplc. activity eluted as a single peak around fraction 15 for all t-cell lines tested. this fraction induced the highest production of ifn-gamma by the lines and was shown by sds-polyacrylamide gel electrophoresis and silver stainin ... | 1999 | 10507366 |
| cowdria ruminantium infection in ticks in the kruger national park. | adult amblyomma hebraeum ticks, the principle vector of heartwater (cowdriosis) of domestic ruminants in southern africa, were collected in pheromone traps placed in kruger national park, an exclusively wildlife sanctuary in south africa. these ticks transmitted cowdria ruminantium, the rickettsial agent causing heartwater, to a susceptible goat, resulting in acute, fatal disease. c ruminantium was isolated in bovine endothelial cell culture from the plasma of this animal during the febrile stag ... | 1999 | 10515616 |
| experimental cross-infections with ehrlichia phagocytophila and human granulocytic ehrlichia-like agent in cows and horses. | four cows and four horses were infected experimentally with ehrlichia phagocytophila, the cause of tickborne fever in ruminants, and with human granulocytic ehrlichia-like agent, a recently discovered species that infects people, horses and dogs in the usa and europe. they were infected in either order, 30 days apart, to investigate serological cross-reactivity within the ephagocytophila genogroup. the course of infection was assessed by routine clinical, haematological, serological and polymera ... | 1999 | 10515618 |