Publications

ehrlichiosis with systemic sepsis syndrome.	the diversity of presenting symptoms with ehrlichia infections makes diagnosis difficult. rash is infrequent. a febrile illness in the summer with thrombocytopenia should arouse suspicion of possible ehrlichiosis.	1997	9130874
development and use of specific polymerase reaction for the detection of an organism resembling ehrlichia sp. in white-tailed deer.	the role of white-tailed deer (odocoileus virginianus) in the epidemiology of ehrlichia chaffeensis and the agent of human granulocytic ehrlichiosis (hge) is not fully understood, and diagnostic procedures may be complicated by the recent detection of 16s rdna sequence from an ehrlichia sp.-like organism in wild deer. a specific forward primer (dga) and an ehrlichia spp. reverse primer (ga1ur) were constructed to amplify this new, distinct ehrlichia sp.-like 16s rdna. the dga primer, a forward p ...	1997	9131554
dogs infected with a human granulocytotropic ehrlichia spp. (rickettsiales: ehrlichieae).	dogs were found to be susceptible to human granulocytotropic ehrlichia spp. infection was produced through the bite of ixodes scapularis say (= dammini spielman, clifford, piesman & corwin) nymphs and adults that acquired infection while feeding as larvae on experimentally infected mice. dogs were also infected by intravenous injection of mouse blood or dog blood from parasitemic donors. parasites were demonstrable in neutrophils within 8 or 9 d after nymphs began feeding; prepatent periods were ...	1997	9439127
[serologic studies on the occurrence of bovine ehrlichiosis in the cantons zürich, schaffhausen, thurgau, st. gallen and obwalden].	the purpose of this study was to investigate the geographical distribution of bovine ehrlichiosis in the cantons zürich, schaffhausen, thurgau, st. gallen and obwalden. to this end, an indirect immunofluorescence assay was established. the diagnostic sensitivity and specificity was estimated to be close to 100% based on the results obtained with several reference sera from the us national veterinary services laboratories and the seroconversion panels of 20 heifers and cows. blood samples from 25 ...	1997	9451917
morphological evidence for infection of impala, aepyceros melampus, platelets by a rickettsia-like organism.	ultrastructural studies revealed the presence of a parasite, believed to be ehrlichia platys, in the blood platelets of impala. at the time of blood sampling all the animals appeared healthy. this is the first report on the presence of this rickettsia in these animals, previously described in canine platelets.	1997	9551485
isolation and characterization of ehrlichia chaffeensis strains from patients with fatal ehrlichiosis.	two new isolates of ehrlichia chaffeensis (designated jax and st. vincent) were obtained from patients with fatal ehrlichial infections. patients developed characteristic manifestations of severe disease due to e. chaffeensis, including marked thrombocytopenia, pulmonary insufficiency, and encephalopathy. primary isolation was achieved in dh82 cells; the jax and st. vincent isolates were detected within 19 and 8 days postinoculation, respectively. the isolates were characterized by molecular eva ...	1997	9316896
comparison of major antigenic proteins of six strains of the human granulocytic ehrlichiosis agent by western immunoblot analysis.	the etiologic agent of human granulocytic ehrlichiosis (hge) is an obligate intracellular bacterium. in 1996, blood specimens from 53 patients suspected of having hge were examined by indirect fluorescent antibody (ifa) testing with the hge agent no. 13 isolate as the antigen, by nested pcr, and by culture. all patients resided in westchester county, n.y. twelve patient specimens were positive for ifa (titer > or = 1:40). seven of these were also positive by pcr. of the seven specimens positive ...	1997	9316916
antigenic diversity of granulocytic ehrlichia isolates from humans in wisconsin and new york and a horse in california.	the agent of human granulocytic ehrlichiosis (hge), ehrlichia phagocytophila, and ehrlichia equi are very similar. hge is of variable severity. genetic and antigenic differences among 3 human isolates (webster, spooner, and ny-8) and 1 horse isolate (mrk) were evaluated. the 16s rrna gene sequences were identical in all human isolates. by use of 5 homologous antisera from these 3 humans and 1 horse and an additional 5 antisera in heterologous reactions, the immunodominant antigens of each isolat ...	1997	9333162
thrombocytopathia and light-chain proteinuria in a dog naturally infected with ehrlichia canis.	a 6-year-old dog was presented for evaluation of recurrent epistaxis. platelet counts, biochemical tests, and coagulation tests were within the normal range, but a mucosal bleeding time was prolonged; there was hyperproteinemia and a monoclonal gammopathy. heterogeneity of light chains appeared in urine, however, thus suggesting that the gammopathy was polyclonal. platelet aggregation tests showed decreased responsiveness to collagen. an ehrlichia canis indirect fluorescent-antibody titer was po ...	1997	9348500
canine monocytic ehrlichiosis: a retrospective study of 100 cases, and an epidemiological investigation of prognostic indicators for the disease.	one hundred cases of monocytic ehrlichiosis diagnosed in israeli dogs were confirmed by the presence of anti-ehrlichia canis indirect immunofluorescent antibody titres greater than 1:40. the disease occurred in all age groups and there was no sex predilection. german shepherd dogs were significantly over-represented whereas crossbreed dogs were significantly under-represented (p > 0.0005). the most common clinical signs were depression, lethargy, lymphadenomegaly, fever, anorexia, panting, pale ...	1997	9351183
primary bone marrow progenitors of both granulocytic and monocytic lineages are susceptible to infection with the agent of human granulocytic ehrlichiosis.	human granulocytic ehrlichiosis (hge) is an emerging tickborne infection resulting in an acute febrile illness associated with cytopenias and characteristic intracellular organisms within peripheral blood granulocytes. the etiologic agent of hge has recently been isolated and cultivated in the hl-60 promyelocytic leukemia cell line, but the spectrum of host cells that it naturally infects remains unknown. to determine if normal hematopoietic progenitors could be targets of infection, cd34+ prima ...	1997	9359749
clinical findings in cows after experimental infection with ehrlichia phagocytophila.	the goal of this study was to determine the clinical signs and course of disease in five lactating cows and in five dry cows after experimental infection with ehrlichia phagocytophila. ten clinically healthy swiss braunvieh cows, seronegative for e. phagocytophila, were injected with 50 ml of whole blood containing e. phagocytophila. the cows were examined daily for 21 days, and blood samples were collected for microscopic examination of leukocytes for the infective agent. all cows became ill wi ...	1997	9360466
antibodies to ehrlichia equi in dogs from the northeastern united states.	to determine whether dogs living in tickinfested areas of the northeastern united states had been exposed to ehrlichia equi, an etiologic agent of granulocytic ehrlichiosis.	1997	9364226
natural history of ehrlichia chaffeensis (rickettsiales: ehrlichieae) in the piedmont physiographic province of georgia.	the roles of wild mammals and ticks in the epidemiology of ehrlichia chaffeensis at a suspected endemic site were investigated using serologic testing, culture, and polymerase chain reaction (pcr) supported by restriction endonuclease analysis and dna sequencing. antibodies reactive to e. chaffeensis (> or = 1:64) were detected in 92% of white-tailed deer (odocoileus virginianus), 21% of raccoons (procyon lotor), and 8% of opossums (didelphis virginianus), but not in 8 other species of mammals. ...	1997	9379294
laboratory findings in cows after experimental infection with ehrlichia phagocytophila.	the goal of this study was to assess various hematological variables in 10 cows after experimental infection with ehrlichia phagocytophila. blood samples were collected at regular intervals for examination of leukocytes for ehrlichia organisms and for determination of hematological and biochemical variables. in addition, pcr amplification was performed throughout the disease period on blood and milk samples for the detection of e. phagocytophila organisms. the time of seroconversion and the dura ...	1997	9384282
western immunoblotting analysis of the antibody responses of patients with human monocytotropic ehrlichiosis to different strains of ehrlichia chaffeensis and ehrlichia canis.	in order to evaluate the relative sensitivity of the detection of antibodies against various antigenic proteins of ehrlichia chaffeensis for the diagnosis of the emerging infectious disease human monocytotropic ehrlichiosis, western immunoblotting was performed with 27 serum samples from convalescent patients with antibodies, as demonstrated by indirect immunofluorescence assay. among 22 patients with antibodies reactive with the 120-kda protein, 15 showed reactivity with the 29/28-kda protein(s ...	1997	9384299
preliminary report of infection in dogs related to ehrlichia equi: description of three cases.	the clinical course of naturally infected dogs with e. equi are described. fever (up to 41 degrees c), depression, dysorexia and ascites were observed. laboratory findings revealed mild anemia, inclusion bodies within neutrophils in one dog, thrombocytopenia, hypoproteinemia, hypoalbuminemia and in two dogs hyperglobulinemia. in acute and convalescent dogs sera antibody titers from 1:60 to 1:480 to e. equi using ifa test were detected. clinical resolution was obtained with long-term doxycycline ...	1997	9385608
human granulocytic ehrlichiosis in southern germany: increased seroprevalence in high-risk groups.	to date, human granulocytic ehrlichiosis (hge), the causative agent of which is likely transmitted by ticks in the ixodes ricinus-ixodes persulcatus complex, has not been diagnosed with certainty in patients outside the united states. the presence of a closely related vector tick, i. ricinus, as well as the occurrence of similar ehrlichia spp. of veterinary importance, suggests that this disease is likely to be present in europe. the aim of the present study was to compare the prevalence of anti ...	1997	9399527
coexistence of ehrlichia phagocytophila and borrelia burgdorferi sensu lato in ixodes ricinus ticks from italy as determined by 16s rrna gene sequencing.		1997	9399564
construction and initial analysis of a representative lambda zapii expression library of the intracellular rickettsia cowdria ruminantium: cloning of map1 and three other cowdria genes.	the causative agent of heartwater, the rickettsia cowdria ruminantium, is very poorly understood at the molecular level owing to a profound lack of suitable tools. we have developed an immunoaffinity chromatographic method to purify c. ruminantium from host cell components and the purified rickettsial cells have been used to prepare substantially pure cowdria dna. this dna has been used to construct what we believe to be the first fully representative c. ruminantium expression library. a clone c ...	1997	9404845
[does the infectious disease, human ehrlichiosis, exist in sweden? ticks get a hold of new zoonoses].	human ehrlichiosis diseases, decently recognised as emerging human infections in the usa, are caused by vector-borne, strictly intracellular bacteria of the family rickettsiaceae. human monocytic ehrlichiosis is caused by ehrlichia schaffeensis, whereas the agent causing human granulocytic ehrlichiosis (hge) has yet to be identified [1]. the putative increase in the occurrence of these primary zoonoses is dependent on the complex relationship between the infectious agents, the vectors, and the h ...	1997	9411085
[occurrence of bovine ehrlichiosis in the canton obwalden].	due the examination of six brown swiss cows the "schinberg-fever" a clinical picture known for years in central switzerland could be identified as bovine ehrlichiosis. clinical signs were observed 23 to 116 days after the animals were turned out on pasture. main symptoms were fever and reduced milk yield. all animals were infested with ticks and showed a severe leucopenia. in buffy coat preparations ehrlichia phagocytophila could be identified in neutrophils and eosinophils, rarely in monocytes. ...	1997	9411737
prospective study of equine colic risk factors.	a 1 year prospective study was conducted on 31 horse farms to identify risk factors for equine colic. farms were randomly selected from a list from 2 adjacent counties of virginia and maryland, usa. the association between colic and farm or individual horse risk factors related to management, housing, pasture, use, nutrition, health and events was first examined by univariate statistical analysis. individually significant (p < = 0.25 for farm factors, p < = 0.10 for horse factors) variables were ...	1997	9413718
comparison of indirect immunofluorescence for ehrlichia phagocytophila and ehrlichia equi in horses.		1997	9413725
ehrlichia phagocytophila genogroup rickettsiae in ixodid ticks from california collected in 1995 and 1996.	a total of 1,246 ixodid ticks collected in 1995 and 1996 from seven california counties were examined for the presence of ehrlichia phagocytophila genogroup rickettsiae by using a nested pcr technique. of 1,112 adult ixodes pacificus cooley and kohls ticks tested, nine pools, each containing five ticks, were positive (minimum percentage of ticks harboring detectable ehrlichiae, 0.8%). positive ticks were limited to four of the seven counties (sonoma, el dorado, santa cruz, and orange). in santa ...	1997	9230373
pcr amplification and comparison of nucleotide sequences from the groesl heat shock operon of ehrlichia species.	degenerate pcr primers derived from conserved regions of the eubacterial groesl heat shock operon were used to amplify groesl sequences of ehrlichia equi, ehrlichia phagocytophila, the agent of human granulocytic ehrlichiosis (hge), ehrlichia canis, bartonella henselae, and rickettsia rickettsii. the groesl nucleotide sequences were less conserved than the previously determined 16s rrna gene sequences of these bacteria. a phylogenetic tree derived from deduced groel amino acid sequences was simi ...	1997	9230387
experimental infection with ehrlichia phagocytophila and babesia divergens in cattle.	nine norwegian red cattle, 9-12 months old, were inoculated simultaneously with ehrlichia (cytoecetes) phagocytophila and babesia divergens. ten cattle of the same breed and age were kept as controls. clinical evaluation was done on a daily basis and rectal temperatures were recorded every morning for 4 weeks post inoculation. blood and serum samples were collected regularly during the observation period. sera were examined for the presence of antibodies to e. phagocytophila and b. divergens by ...	1997	9230674
short report: geographic distribution of different genetic types of ehrlichia chaffeensis.	the 120-kd protein gene of ehrlichia chaffeensis was used to characterize ehrlichial dna from seven pools of adult amblyomma americanum ticks. ticks from missouri, kentucky, and north carolina contained e. chaffeensis dna of the arkansas strain genotype. ticks from north carolina also contained ehrlichiae of the sapulpa strain genotype, originally identified in oklahoma.	1997	9230803
the cold zone: a curious convergence of tick-transmitted diseases.	in recent years, investigators have gained an increasing appreciation of the complexity of the lyme disease transmission cycle with regard to the number of pathogens involved. babesia microti, a blood parasite that is related to the organism that causes malaria, frequently accompanies the lyme disease spirochete in the mouse reservoir. recently, a newly described ehrlichia species related to ehrlichia equi has been found to be transmitted by the deer tick. human infections with these agents alon ...	1997	9233662
is human granulocytic ehrlichiosis a new lyme disease? review and comparison of clinical, laboratory, epidemiological, and some biological features.	human granulocytic ehrlichiosis (hge) and lyme disease are caused by infectious agents transmitted by deer ticks (ixodes scapularis). because of the shared tick vector and increased seroprevalence of hge in patients with lyme disease, there is some confusion about the identity of these infectious agents and the clinicopathologic spectrum of the disease. hge is an acute febrile illness associated with leukopenia, thrombocytopenia, and increased serum activities of hepatic transaminases. in contra ...	1997	9233663
the prevalence of serum antibodies to tick-borne infections in cattle in smallholder dairy farms in murang'a district, kenya; a cross-sectional study.	the most important tick-borne disease of cattle in eastern, central and southern africa is east coast fever (ecf) caused by theileria parva and transmitted by the tick rhipicephalus appendiculatus. other less-important tick-borne diseases in cattle are benign theileriosis caused by theileria mutans, babesiosis caused by babesia bigemina, anaplasmosis caused by anaplasma marginale and cowdriosis caused by cowdria ruminatum. in murang's district, central province of kenya, five agroecological zone ...	1997	9234414
antibodies to multiple tick-borne pathogens of babesiosis, ehrlichiosis, and lyme borreliosis in white-footed mice.	serum samples from peromyscus leucopus (white-footed mouse), collected in connecticut (usa) in 1983, 1985, and during 1990 to 1993, were analyzed by an enzyme-linked immunosorbent assay (elisa) or indirect fluorescent antibody (ifa) staining methods for antibodies to borrelia burgdorferi (strain 2591), babesia microti, ehrlichia chaffeensis (arkansas strain), and ehrlichia equi (mrk strain). of the 294 serum samples tested, 160 (54%) contained immunoglobulins to one or more of these pathogens. t ...	1997	9249691
intrauterine infection with ehrlichia phagocytophila in a cow.	an infection with ehrlichia phagocytophila, the agent of tickborne fever, can cause abortion or stillbirth in cows in late pregnancy but, to the authors' knowledge, there have been no reports of intrauterine infection in cows followed by clinical signs in the calf. to study the effect of e phagocytophila on the fetus, a cow was infected experimentally after 270 days of pregnancy. it developed the clinical and haematological signs characteristic of tickborne fever six days after infection. at 287 ...	1997	9265711
serological responses to ehrlichia equi, ehrlichia chaffeensis, and borrelia burgdorferi in patients from new york state.	serological testing at the new york state department of health for human granulocytic ehrlichiosis in the residents of westchester county, n.y., was performed with specimens from 176 patients by the indirect fluorescent-antibody (ifa) technique with ehrlichia equi mrk-infected neutrophils. to understand whether human monocytotropic ehrlichiosis also occurs in this northeastern geographic region, specimens were also tested for antibodies to ehrlichia chaffeensis arkansas. screening tests and immu ...	1997	9276387
comparison of pcr and culture to the indirect fluorescent-antibody test for diagnosis of potomac horse fever.	potomac horse fever is an acute systemic equine disease caused by ehrlichia risticii. currently, serologic methods are widely used to diagnose this disease. however, serologic methods cannot determine whether the horse is presently infected or has been exposed to ehrlichial antigens in the past. the purpose of the present study was to compare the sensitivities of the nested pcr and cell culture with that of the indirect fluorescent-antibody (ifa) test for the diagnosis of potomac horse fever. bl ...	1997	9276390
granulocytic ehrlichiosis in two dogs in switzerland.	this case report describes two dogs with granulocytic ehrlichiosis. dog 1 was a male labrador retriever with clinical signs of lymphosarcoma. dog 2 was a female airedale terrier, whose clinical signs included apathy, pyrexia, diarrhea, and abdominal pain. examination of blood smears revealed ehrlichia organisms in the neutrophils of both dogs. there was thrombocytopenia in both dogs, and dog 2 also had leukopenia. in both dogs, bands of identical length were amplified from dna of leukocytes via ...	1997	9276407
human monocytic and granulocytic ehrlichioses. discovery and diagnosis of emerging tick-borne infections and the critical role of the pathologist.	human monocytic ehrlichiosis and human granulocytic ehrlichiosis are emerging tick-borne infections in the united states. the clinical presentations of these two distinct, potentially life-threatening infections are fever, headache, myalgia, and other diagnostically nonspecific symptoms. physician awareness is lacking and appropriate diagnostic tests are still not widely available. because few documented cases have been autopsied, the pathology of human monocytic ehrlichiosis and human granulocy ...	1997	9278605
deer ticks (ixodes scapularis) and the agents of lyme disease and human granulocytic ehrlichiosis in a new york city park.	rodent trapping and drag sampling in van cortlandt park, new york city, yielded all stages of ixodes scapularis, the deer tick vector of lyme disease and human granulocytic ehrlichiosis (hge). polymerase chain reaction analyses of the ticks showed borrelia burgdorferi and the ehrlichia sp. that causes hge.	1997	9284380
[hepatozoon canis infection of dogs in germany: case report and epidemiology].	this paper reports on a case of hepatozoonosis of a dog imported from italy to germany being additionally infected with ehrlichia canis and babesia canis. furthermore, a survey of the epidemiology of the hepatozoon canis infection is presented.	1997	9289886
the early humoral response in human granulocytic ehrlichiosis.	the early antibody response in patients with human granulocytic ehrlichiosis (hge) and in mice infected with the hge agent was characterized by using sera to probe lysates of hl-60 cells infected with hge organisms. sera were obtained from 18 patients with hge, mostly within the first 6 weeks of clinical infection, and from mice infected with the hge agent for up to 3 weeks. a 44-kda antigen was reactive with igg in all 18 patients, and igg to 40-, 65-, and 80-kda antigens was present in 6, 8, a ...	1997	9291316
sequence and characterization of an ehrlichia chaffeensis gene encoding 314 amino acids highly homologous to the nad a enzyme.	dna sequence analysis of the nada gene of ehrlichia chaffeensis revealed a 942 bp open reading frame with the capacity to encode 314 amino acids. the amino acid sequence of the e. chaffeensis quinolinate synthetase a (nad/a) has 53.6% identity and 82% similarity to the nad a of the cyanelle of cyanophora paradoxa. portions of the homologous genes of e. canis and e. muris were also sequenced. the amino acid sequences of the nad a of e. canis and e. muris have 89.2% and 93.2% homology, respectivel ...	1997	9297820
detection of genomic polymorphisms among isolates of the intracellular bacterium cowdria ruminantium by random amplified polymorphic dna and southern blotting.	sixteen primers were successfully used in a rapd assay to generate reproducible fingerprints for six isolates of cowdria ruminantium, a tick-transmitted rickettsia of ruminants. distinction between stocks was possible by using one or at most two primers. two stocks were very similar although originating from widely distant geographical regions. a genetic distance tree was constructed by analysing 108 fragments in pairwise comparison between stocks. three amplification fragments probed with c. ru ...	1997	9297823
human ehrlichiosis in thailand.		1997	9298007
different organisms associated with heartwater as shown by analysis of 16s ribosomal rna gene sequences.	cowdria ruminantium is a rickettsial parasite which causes heartwater, a economically important disease of domestic and wild ruminants in tropical and subtropical africa and parts of the caribbean. because existing diagnostic methods are unreliable, we investigated the small-subunit ribosomal rna (srrna) gene from heartwater-infected material to characterise the organisms present and to develop specific oligonucleotide probes for polymerase chain reaction (pcr) based diagnosis. dna was obtained ...	1997	9299697
development of an in vitro cloning method for cowdria ruminantium.	cowdria ruminantium is a tick-borne rickettsia which causes severe disease in ruminants. all studies with c. ruminantium reported so far were carried out with stocks consisting of infective blood collected from reacting animals or from the same stocks propagated in vitro. cloned isolates are needed to conduct studies on immune response of the host, on genetic diversity of the parasite, and on mechanisms of attenuation and the development of vaccines. a method of cloning based on the particular c ...	1997	9302217
clinical manifestations of infectious canine cyclic thrombocytopenia.	this paper describes five naturally occurring clinical cases of infectious canine cyclic thrombocytopenia that were the first serologically confirmed cases of ehrlichia platys infection in israel. in the usa this disease is considered subclinical, but the dogs in this study developed distinct clinical abnormalities. the signs observed by the owners included anorexia, lethargy, depression, weight loss and a mucopurulent nasal discharge. the principal findings on physical examination included lymp ...	1997	9308149
positive lyme disease serology in patients with clinical and laboratory evidence of human granulocytic ehrlichiosis.	in 10 consecutive patients with an acute febrile illness, human granulocytic ehrlichiosis was confirmed with specific polymerase chain reaction studies, serologic conversion, or both. although no patients had the clinical features most suggestive of early lyme disease (eg, erythema migrans or cranial nerve palsy), tests for antibody to borrelia burgdorferi produced a reaction in most patients. in 6 of 7 patients (86%) with evaluable results, enzyme-linked immunosorbent assay yielded positive or ...	1997	9024062
a population-based seroepidemiologic study of human granulocytic ehrlichiosis and lyme borreliosis on the west coast of sweden.	ehrlichioses are emerging infections in the united states. human granulocytic ehrlichiosis (hge) and lyme borreliosis (lb) are acquired after ixodes ricinus-complex tick bites. an ongoing seroepidemiologic study of the 185 of the 356 permanent residents of the koster islands in sweden was expanded to include ehrlichioses. ehrlichial antibodies were measured by ifa using ehrlichia equi and ehrlichia chaffeensis. borrelia burgdorferi igg elisa-seropositive subjects were confirmed by western blot. ...	1997	9041353
characterization of a new isolate of ehrlichia platys (order rickettsiales) using electron microscopy and polymerase chain reaction.	a mixed-breed pup approximately 3 months old obtained in north central oklahoma by the laboratory animal resources unit of oklahoma state university presented with platelet inclusions. the dog developed severe thrombocytopenia (< 10,000 microliters-1) following the appearance of inclusions. blood films were monitored daily and when about 75% of platelets had inclusions, samples were collected in edta and processed for electron microscopic (em) studies and polymerase chain reaction (pcr). em stud ...	1997	9066046
serological survey of heartwater relative to the distribution of the vector amblyomma variegatum and other tick species in north cameroon.	a study was carried out on the spatial and temporal distribution of amblyomma variegatum and other ticks infesting sheep and goats in northern cameroon. a serological survey of heartwater (cowdriosis) using a competitive elisa was concurrently carried out in the same flocks. a. variegatum was found to be the most predominant species accounting for 48.3% of all the ticks collected. other species identified included rhipicephalus sulcatus, r. lunulatus, r. turanicus, boophilus decoloratus, b. annu ...	1997	9066062
clinical and clinicopathologic abnormalities in greyhounds with cutaneous and renal glomerular vasculopathy: 18 cases (1992-1994)	to determine clinical signs and clinicopathologic abnormalities in greyhounds with cutaneous and renal glomerular vasculopathy and to determine whether there were any differences between dogs with and without renal azotemia.	1997	9074681
clinical features and serology of 14 dogs affected by granulocytic ehrlichiosis in sweden.	the clinical features and the titres to ehrlichia equi, e canis, e risticii, rickettsia rickettsii and borrelia afzelii in 14 swedish dogs, in which ehrlichiosis was diagnosed on the basis of the presence of inclusions in granulocytes, are reported. most of the dogs were moderately ill but made a rapid recovery after treatment with doxycycline. the dogs with inclusions were thrombocytopenic. analysis of the antibody titres indicates that serology to e equi will remain the most appropriate serolo ...	1997	9076917
immunoblot analysis of the immunoglobulin g response to ehrlichia canis in dogs: an international survey.	historically, considerable variation has been reported in the type and severity of clinical and hematologic abnormalities associated with canine ehrlichiosis. because of difficulties associated with the isolation of intracellular monocytic ehrlichia species in tissue culture systems, few e. canis isolates are available for comparative microbiologic studies. to address the issue of potential e. canis antigenic diversity in different regions of the world, dog sera reactive by indirect fluorescent ...	1997	9087922
fourth nerve palsy caused by ehrlichia chaffeensis.	two human ehrlichioses occur in the united states: human monocytic ehrlichiosis (hme), which is caused by ehrlichia chaffeensis that infects mononuclear phagocytes in blood and tissue, and human granulocytic ehrlichiosis (hge), an infection of granulocytes that is caused by a similar but phylogenetically distinct organism. the clinical features of both forms of human ehrlichiosis are identical and include nonspecific constitutional manifestations, such as fever, headache, malaise, nausea, vomiti ...	1997	9093962
nested polymerase chain reaction for detection of ehrlichia risticii genomic dna in infected horses.	a nested polymerase chain reaction was developed for amplifying a 529-bp segment of the 16s ribosomal rna gene of ehrlichia risticii from equine buffy coat cells. confirmation of identity of the amplified bands was accomplished by southern hybridization and dna sequencing. the study indicated a detection limit of > 10 copies of the target gene, and specificity for e. risticii as based on a panel of test rickettsiae. ticks (ixodes pacificus) collected in an area of northern california enzootic fo ...	1997	9106958
characterization of an immunoreactive protein from the agent of human granulocytic ehrlichiosis.	a gene that is homologous to the ehrlichia chaffeensis groel operon was recovered and characterized by broad-range pcr amplification of whole blood from patients with human granulocytic ehrlichiosis (hge) and from infected hl60 cell cultures. sequence analysis of an 820-bp dna fragment recovered directly from human blood showed 76.5 and 76.3% identity with cognate sequences from e. chaffeensis and cowdria ruminantium, respectively. analysis of a 1.6-kb dna fragment derived from an hge agent-infe ...	1997	9114402
analysis of t-cell responses in cattle immunized against heartwater by vaccination with killed elementary bodies of cowdria ruminantium.	cattle were successfully immunized against heartwater with a lysate of cowdria ruminantium formulated in freund's adjuvant. vaccinated animals proved fully resistant to virulent challenge 3 and 10 months after vaccination. for the first time a helper t lymphocyte response to cowdria antigens was observed and characterized. cowdria-specific t-cell lines generated from vaccinated animals by in vitro restimulation with cowdria lysates are 95 to 100% cd4+, are mhc class ii restricted, and produce ga ...	1997	8975917
an ehrlichia strain from a llama (lama glama) and llama-associated ticks (ixodes pacificus).	an ehrlichia was identified in the blood of a diseased llama (lama glama). sequencing of its 16s rrna gene showed the ehrlichia to be closely related to members of the ehrlichia phagocytophila genogroup. the agent was also found in a pool of ticks (ixodes pacificus) collected at the llama site.	1997	9157118
western immunoblot analysis of haemobartonella muris and comparison of 16s rrna gene sequences of h. muris, h. felis, and eperythrozoon suis.	infectious agents were isolated from the spleens of three wild mice (apodemus argenteus) by intraperitoneal inoculation of the spleen homogenate into laboratory mice. the laboratory mice developed clinical signs and splenomegaly, and three isolates were maintained by passage in mice. tetracyclines were effective in preventing infection of mice with these agents, but streptomycin and penicillin were ineffective. the agents did not grow in bacterial growth media or chicken embryos. in smears of bl ...	1997	9157135
natural infection of small mammal species in minnesota with the agent of human granulocytic ehrlichiosis.	the natural reservoirs for the agent of human granulocytic ehrlichiosis (hge) are suspected to be the small mammals that host immature stages of ixodes scapularis ticks. to determine if such small mammals are naturally infected, we collected blood and serum samples from small mammal species in rural and suburban areas of minneapolis and st. paul, minn. samples were collected from white-footed mice (peromyscus leucopus), eastern chipmunks (tamias striatus), southern red-backed voles (clethrionomy ...	1997	9157141
propagation of granulocytic ehrlichia spp. from human and equine sources in hl-60 cells induced to differentiate into functional granulocytes.	ehrlichia spp. from human and equine sources in the northeastern unites states were detected by pcr, isolated, and propagated in the hl-60 promyelocytic leukemia cell line. growth of ehrlichia from both equine and human sources was enhanced by addition of retinoic acid, which causes granulocytic differentiation of the hl-60 cells. dna sequencing of a portion of the 16s rdna gene supported the hypothesis that the same pathogen was responsible for both equine and human granulocytic ehrlichiosis.	1997	9157154
serologic and molecular detection of granulocytic ehrlichiosis in rhode island.	a new indirect fluorescent-antibody (ifa) assay with antigen produced in vitro in the human promyelocytic leukemia cell line hl60 was used to identify the first recognized case of human granulocytic ehrlichiosis in rhode island. this ifa assay was used to detect granulocytic ehrlichiae in white-footed mice and in a dog inhabiting the area surrounding the patient's residence. host-seeking ixodes scapularis ticks found in the same habitat also were infected. i. scapularis ticks collected from othe ...	1997	9157157
an indirect immunofluorescence assay using a cell culture-derived antigen for detection of antibodies to the agent of human granulocytic ehrlichiosis.	an indirect immunofluorescence assay for the detection of human antibodies to the agent of human granulocytic ehrlichiosis (hge) was developed and standardized. antigen was prepared from a human promyelocytic leukemia cell line (hl-60) infected with a tick-derived isolate of the hge agent (usg3). suitable antigen presentation and preservation of cellular morphology were obtained when infected cells were applied and cultured on the slide, excess medium was removed, and cells were fixed with aceto ...	1997	9163471
human disease in europe caused by a granulocytic ehrlichia species.	human granulocytic ehrlichiosis (hge) was recently described in north america. it is caused by an ehrlichia species closely related to ehrlichia phagocytophila and ehrlichia equi, recognized to infect mostly ruminants and horses, respectively. the vector in north america is the tick ixodes scapularis, which is also the vector of the lyme disease agent, borrelia burgdorferi. previous serologic studies in patients with a diagnosis of lyme borreliosis indicate that hge may exist in europe. we repor ...	1997	9163481
seroepidemiology of emerging tickborne infectious diseases in a northern california community.	a seroprevalence and risk factor study of emerging tickborne infectious diseases (lyme disease, ehrlichiosis, and babesiosis) was conducted among 230 residents of a semirural community in sonoma county, california. over 50% of residents reported finding a tick on themselves in the preceding 12 months. samples from 51(23%) residents were seroreactive to antigens from one or more tickborne disease agents: 1.4% to borrelia burgdorferi, 0.4% to ehrlichia equi, 4.6% to ehrlichia chaffeensis, and 17.8 ...	1997	9180183
tick-borne diseases in the united states.		1997	9191750
human ehrlichiosis.	ten years ago, tick-borne ehrlichiosis infection was primarily a problem in dogs, cattle, and sheep. today hundreds of people have been infected by newly recognized ehrlichia species. if infection is detected early, treatment is relatively simple and usually effective. late diagnosis, on the other hand, carries serious morbidity or even death. dr. glushko discusses the history, epidemiology, and clinical aspects of human ehrlichiosis and provides information on both treatment and prevention.	1997	9194875
attempted transmission of human granulocytotropic ehrlichia (hge) by amblyomma americanum and amblyomma maculatum.	transstadial transmission of human granulocytotrophic ehrlichia (hge) was attempted in dogs using amblyomma americanum (l.) and a. maculatum koch, two species that, as adults, feed readily on human beings. larvae and nymphs were acquisition-fed on a dog that was parasitemic with hge. two months later, following digestion of the blood meal and subsequent molting to nymphal or adult stage, these ticks were fed to repletion on hge-naive dogs. none of the dogs developed clinical evidence of ehrlichi ...	1997	9195722
characterization of the subclinical phase of canine ehrlichiosis in experimentally infected beagle dogs.	beagle dogs were examined during the subclinical phase of canine ehrlichiosis under controlled conditions. emphasis was placed on gathering data before artificial inoculation with ehrlichia canis, and comparing these data with those of the subclinical phase of the disease. in this study all dogs were clinically healthy throughout the 6 month examination period. all subclinically infected dogs had ifa antibody titers to e. canis at a dilution varying from 1:2560 to 1:20480. the most prominent hae ...	1997	9195740
isolation of ehrlichia chaffeensis from wild white-tailed deer (odocoileus virginianus) confirms their role as natural reservoir hosts.	field and experimental studies have implicated white-tailed deer (odocoileus virginianus) as probable reservoir hosts for ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis, but natural infection in deer has not been confirmed through isolation of e. chaffeensis. thirty-five white-tailed deer collected from three amblyomma americanum-infested populations in georgia were examined for evidence of e. chaffeensis infection by serologic, molecular, cell culture, and xenodiagno ...	1997	9196173
comparison of nested pcr with immunofluorescent-antibody assay for detection of ehrlichia canis infection in dogs treated with doxycycline.	a partial 16s rrna gene was amplified in ehrlichia canis-infected cells by nested pcr. the assay was specific and did not amplify the closely related ehrlichia chaffeensis, ehrlichia muris, neorickettsia helminthoeca, and sf agent 16s rrna genes. the assay was as sensitive as southern hybridization, detecting as little as 0.2 pg of e. canis dna. by this method, all blood samples from four dogs experimentally infected with e. canis were positive as early as day 4 postinoculation, which was before ...	1997	9196207
anti-ehrlichia chaffeensis antibody complexed with e. chaffeensis induces potent proinflammatory cytokine mrna expression in human monocytes through sustained reduction of ikappab-alpha and activation of nf-kappab.	ehrlichia chaffeensis is an obligatory intracellular bacterium that infects monocytes and macrophages and is the etiologic agent of human ehrlichiosis in the united states. our previous studies showed that the exposure of human monocytes to e. chaffeensis induces the expression of interleukin-1beta (il-1beta), il-8, and il-10 genes in vitro but not the expression of tumor necrosis factor alpha (tnf-alpha) and il-6 mrnas. in this study, the effect of anti-e. chaffeensis antibody complexed with e. ...	1997	9199464
tyrosine phosphorylation is required for ehrlichial internalization and replication in p388d1 cells.	replication of ehrlichia risticii was inhibited in p388d1 cells when a protein tyrosine kinase inhibitor (genistein or herbimycin a) was added after internalization of the organism at 3 h postinfection. upon addition of genistein at day 1, 2, 3, or 4 postinfection, further proliferation of e. risticii was prevented. the inhibition was reversible, since regrowth of e. risticii occurred upon the removal of genistein. genistein prevented spreading of e. risticii from p388d1 cells to thp-1 cells. ge ...	1997	9199472
human monocytic ehrlichiosis in children.	much of what is known about human monocytic ehrlichiosis (hme) is based upon studies with adult patients.	1997	9200384
simultaneous human granulocytic ehrlichiosis and lyme borreliosis.		1997	9203428
development and evaluation of a recombinant antigen, monoclonal antibody-based competitive elisa for heartwater serodiagnosis.	cowdria ruminantium is the etiologic agent of heartwater, a tick-transmitted foreign animal disease with considerable potential for entrance into the usa. a competitive enzyme-linked immunosorbent assay (celisa) was developed to detect serologic responses to c. ruminantium infection. the celisa utilized a recombinant form of the c. ruminantium major antigenic protein (map-1) as the antigen and an anti-map-1 monoclonal antibody as the competing indicator reagent. experimental antisera to c. rumin ...	1997	9211230
prevalence of the rickettsial agent of human granulocytic ehrlichiosis in ticks from a hyperendemic focus of lyme disease.		1997	9213773
ehrlichia sennetsu groe operon and antigenic properties of the groel homolog.	a clone expressing an immunoreactive 55-kilodalton (kda) protein of ehrlichia sennetsu, the causative agent of human sennetsu ehrlichiosis, was isolated from a gene library of this organism. sequence analysis of the dna insert revealed two open reading frames, encoding proteins of 10,620 and 58,225 kda, respectively. these deduced amino acid sequences were homologous to those of the groes and groel heat shock proteins (hsp) of other bacteria, respectively. phylogenetic trees based on groes and g ...	1997	9215585
transmission of the agent of human granulocytic ehrlichiosis by host-seeking ixodus scapularis (acari:ixodidae) in southern new york state.	ixodes scapularis say nymphs collected from a natural focus of human granulocytic ehrlichiosis (hge) in westchester county, new york, transmitted the hge agent to uninfected mice in the laboratory. infection was demonstrated in 3 of 8 mice by polymerase chain reaction analysis of whole blood and microscopic examination of blood smears for morulae. two of these mice were also positive by xenodiagnosis. positive xenodiagnostic larvae maintained infection through molting and transferred infection t ...	1997	9220669
acute colitis in adult horses. a review with emphasis on aetiology and pathogenesis.	this review article describes the different aetiological agents known or suspected to cause colitis in the adult horse, namely salmonella spp., clostridium spp., ehrlichia risticii, cyathostomes, fungi, various antibiotics, drugs, and toxins, with emphasis on their mechanism of action. for each of the infectious agents, diagnostic procedures are indicated. the effects of endotoxin can be important in all forms of equine colitis.	1997	9225437
immunodominant major outer membrane proteins of ehrlichia chaffeensis are encoded by a polymorphic multigene family.	several immunodominant major proteins ranging from 23 to 30 kda were identified in the outer membrane fractions of ehrlichia chaffeensis and ehrlichia canis. the n-terminal amino acid sequence of a 28-kda protein of e. chaffeensis (one of the major proteins) was determined. the gene (p28), almost full length, encoding the 28-kda protein was cloned by pcr with primers designed based on the n-terminal sequence of the e. chaffeensis 28-kda protein and the consensus sequence between the c termini of ...	1998	9423849
cellular immune responses of cattle to cowdria ruminantium.	peripheral blood mononuclear cells (pbm) from cattle immunised against cowdria ruminantium infection (heartwater), proliferated in vitro in the presence of either infected autologous endothelial cells pre-treated with t cell growth factors to induce mhc class ii expression, or infected autologous monocytes. proliferation was not observed in pbm cultured with a soluble extract of the agent, but pbm responded to two recombinant antigens of c. ruminantium, namely a 32 kda (map1) and a 21 kda antige ...	1998	9554286
human granulocytic ehrlichiosis in new york.	human granulocytic ehrlichiosis (hge), a potentially fatal tick-borne disease, was first described in the upper midwest in 1994. following reports of suspected cases of ehrlichiosis from new york physicians, descriptive and case-control studies were conducted to characterize the epidemiology and risk factors for hge in new york residents.	1998	9554683
granulocytic ehrlichiosis in dogs from north carolina and virginia.	medical records of 3 dogs from north carolina and 3 dogs from virginia with ehrlichial morulae in circulating neutrophils were studied retrospectively. two clinically distinct disease syndromes, including chronic, moderate to severe anemia (n = 3) and polyarthritis (n = 2) were associated with canine granulocytic ehrlichiosis (cge) in these dogs. one dog was clinically healthy, and abnormalities were not detected during physical examination. clinical signs were nonspecific and included fever, le ...	1998	9560760
a survey of tick-borne bacteria and protozoa in naturally exposed dogs from israel.	antibody reactivity against seven bacterial or protozoal pathogens was measured in sera derived from 40 dogs suspected of a tick-borne disease. sera from 73% (29/40) of the dogs reacted with three or more test antigens. seroreactivity was most prevalent to babesia canis antigen (90%) followed by babesia gibsoni (75%), ehrlichia canis (63%), rickettsia conorii--moroccan strain (58%), rickettsia conorii--israeli strain no. 2 (28%), borrelia burgdorferi (10%) or bartonella vinsonii (berkhoffii) (10 ...	1998	9561701
experimental transmission of ehrlichia canis (rickettsiales: ehrlichieae) by dermacentor variabilis (acari: ixodidae).	four trials were conducted in which laboratory-reared dermacentor variabilis nymphs were exposed to ehrlichia canis by feeding on experimentally infected dogs as soon as classical morulae were detected in peripheral blood monocytes. after molting 25, 50 or 90 adult tick pairs were permitted to feed on 7 ehrlichia-naive dogs. transmission occurred in trials 1 (1/1 dog), 3 (1/1 dog) and 4 (2/2 dogs) but not in trial 2 (0/3 dogs), with 4 of 7 dogs becoming infected. successful transstadial transmis ...	1998	9561712
antibody response to hepatozoon canis in experimentally infected dogs.	canine hepatozoonosis is a disease caused by the tick-borne protozoan hepatozoon canis. five puppies were inoculated by ingestion of rhipicephalus sanguineus ticks experimentally infected with h. canis, and all became infected with h. canis: gametocytes were detected in blood smears from four dogs and schizonts were observed in the spleen and bone marrow of the fifth. antibodies reactive with h. canis gametocytes were detected by the indirect fluorescent antibody test (ifa), with igm detected in ...	1998	9561714
choline availability modulates the expression of tgfbeta1 and cytoskeletal proteins in the hippocampus of developing rat brain.	choline availability influences long-term memory in concert with changes in the spatial organization and morphology of septal neurons, however little is known concerning the effects of choline on the hippocampus, a region of the brain also important for memory performance. pregnant rats on gestational day 12 were fed a choline control (ct), choline supplemented (cs), or choline deficient (cd) diet for 6 days and fetal brain slices were prepared on embryonic day 18 (e18). the hippocampus in these ...	1998	9566615
a dna vaccine protects mice against the rickettsial agent cowdria ruminantium.	a dna vaccine (vcl1010/map1) containing the major antigenic protein 1 (map1) gene of cowdria ruminantium, driven by the human cytomegalovirus (hcmv) enhancer-promoter, was injected intramuscularly into 8-10 week-old female dba/2 mice after treating them with 50 microliters/muscle of 0.5% bupivacaine three days previously. up to 75% of the immunized mice seroconverted and reacted with c. ruminantium antigen blots. splenocytes from immunized mice, but not from control mice, proliferated in respons ...	1998	9568614
immunization of cattle by infection with cowdria ruminantium elicits t lymphocytes that recognize autologous, infected endothelial cells and monocytes.	peripheral blood mononuclear cells (pbmc) from immune cattle proliferate in the presence of autologous cowdria ruminantium-infected endothelial cells and monocytes. endothelial cells required treatment with t-cell growth factors to induce class ii major histocompatibility complex expression prior to infection and use as stimulators. proliferative responses to both infected autologous endothelial cells and monocytes were characterized by expansion of a mixture of cd4+, cd8+, and gammadelta t cell ...	1998	9573061
nitric oxide is produced by cowdria ruminantium-infected bovine pulmonary endothelial cells in vitro and is stimulated by gamma interferon.	nitric oxide (no) is a labile inorganic free radical produced by no synthase from the substrate l-arginine in various cells and tissues including endothelial cells. a substantial elevation of nitrite levels indicative of no production occurred in cultures of cowdria ruminantium-infected bovine pulmonary endothelial cells (bpec) incubated in medium alone. exposure of the infected cultures to recombinant bovine gamma interferon (borifn-gamma) resulted in more rapid production of no, reduced viabil ...	1998	9573097
the agent of human granulocytic ehrlichiosis resides in an endosomal compartment.	the composition of cytoplasmic vacuoles containing the agent of human granulocytic ehrlichiosis (hge) was studied to investigate how this pathogen exists within infected host cells. electron microscopy demonstrated that the hge organism resides in a membrane-bound compartment within hl-60 cells: early forms of the hge agent have a round reticular appearance while later structures are small and dense. vacuoles containing hge bacteria incorporated endocytosed colloidal gold particles, suggesting t ...	1998	9576758
growth of cowdria ruminantium in tissue culture endothelial cell lines from wild african mammals.	endothelial cell cultures were established from several wild african mammalian species. long-term cultures were established from three ruminants, stable antelope (hippotragus niger), buffalo (syncerus caffer), and eland (tragelaphus oryx), and from an omnivore, the bushpig (potamochoerus porcus). cowdria ruminanntium was isolated from plasma of clinically affected animals in these four cell lines and in bovine endothelial cells used routinely for c. ruminantium propagation. nineteen different st ...	1998	9577776
lack of seroreactivity to ehrlichia chaffeensis among rodent populations.	a retrospective serosurvey for antibodies to ehrlichia chaffeensis was conducted on eight species of wild rodents (mus musculus, oryzomys palustris, peromyscus leucopus, rattus norvegicus, reithrodontomys humulis, sciurus carolinensis, sciurus niger, and sigmodon hispidus) from the southeastern united states. serum samples (n = 281) collected between 1973 and 1993 were evaluated using an indirect fluorescent antibody test. all samples, screened at a dilution of 1:32, were negative for antibodies ...	1998	9577793
duration of tick attachment required for transmission of granulocytic ehrlichiosis.	deer tick-transmitted pathogens such as lyme disease spirochetes and babesiae appear to require a period of reactivation and replication during the tick's blood meal before it is able to infect a host. the duration of nymphal tick attachment that is required for transmission of the agent of human granulocytic ehrlichiosis (hge) was determined by removing feeding ticks from mice at various time points. as with spirochetes and babesiae, ehrlichiae infected few mice when ticks were removed prior to ...	1998	9593039
protein kinase a-mediated inhibition of gamma interferon-induced tyrosine phosphorylation of janus kinases and latent cytoplasmic transcription factors in human monocytes by ehrlichia chaffeensis.	ehrlichia chaffeensis, an obligatory intracellular bacterium of monocytes or macrophages, is the etiologic agent of human monocytic ehrlichiosis. our previous study showed that gamma interferon (ifn-gamma) added prior to or at early stage of infection inhibited infection of human monocytes with e. chaffeensis; however, after 24 h of infection, ifn-gamma had no antiehrlichial effect. to test whether ehrlichial infection disrupts janus kinase (jak) and signal transducer and activator of transcript ...	1998	9596710
serological, hematologic, and pcr studies of cattle in an area of switzerland in which tick-borne fever (caused by ehrlichia phagocytophila) is endemic.	the purpose of this study was to examine the seasonal variations in seroprevalence to ehrlichia phagocytophila in cattle pastured during the summer months in an area where tick-borne fever is endemic. the study was performed during a 1-year period from april 1996 to march 1997 and involved 34 cows, 22 pregnant heifers, and 14 calves. blood samples, collected from all 70 cattle once a month, were used to determine serum immunoglobulin g titers by indirect immunofluorescence. in addition, blood sm ...	1998	9605986
inhibition of mhc class i and class ii cell surface expression on bovine endothelial cells upon infection with cowdria ruminantium.	endothelial cells constitute a main target for cowdria ruminantium (cr) and can potentially play a role as antigen presenting cells (apc). therefore, we measured, in vitro, the effect of cr infections on the expression of mhc class i and class ii molecules on bovine umbilical endothelial cells (buec) and on bovine brain endothelial cells (bbec). a dramatic inhibition of the expression of ifngamma induced mhc class ii molecules was observed on buec and to a lesser extent on bbec upon cr infection ...	1998	9613471
studies with recombinant proteins of ehrlichia risticii: identification of strain-specific antigen as a protective antigen.	ehrlichia risticii is the causative agent of potomac horse fever, an acute infectious disease of equines. to study the role of major antigens of e. risticii in protective immune response, we have expressed the genes of the 55 kda, 51 kda and 85/50 kda-strain-specific antigens of the 90-12 (85 kda antigen) and 25-d (50 kda antigen) strains in escherichia coli using prset a, b, c system (invitrogen, san diego, ca). mice immunized with these purified recombinant proteins of e. risticii developed st ...	1998	9615953
a new reason to be nervous about ticks. interview by marc kennedy.		1998	9617302