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Revista Brasileira de Parasitologia... 2022Canine monocytic ehrlichiosis (CME) is one of the most important tick-borne diseases worldwide, with multisystemic presentations. Immune dysregulation has been proposed...
Canine monocytic ehrlichiosis (CME) is one of the most important tick-borne diseases worldwide, with multisystemic presentations. Immune dysregulation has been proposed as the primary mechanism involved in its pathogenesis and in tissue injury in dogs with CME. Experimental infection of German Shepherd dogs in the present study demonstrated that CME caused marked pathological changes in their lymph nodes and spleen, and also gave rise to mononuclear infiltration in organs and tissues. Immunophenotyping of cells in lymph nodes, spleen and injured tissues highlighted differences in lymphocyte subsets, local expression of immunoglobulin subclasses and MHCII molecules between infected and control dogs. These findings suggest that the immunophenotypic and immunopathological changes in dogs with acute experimental CME are related to Th1 bias and compartmentalized immune response.
Topics: Animals; Dog Diseases; Dogs; Ehrlichia canis; Ehrlichiosis; Spleen; Tick-Borne Diseases
PubMed: 35416862
DOI: 10.1590/S1984-29612022020 -
Journal of Clinical Microbiology May 1995Homology in the 16S rDNAs shows that the agent of human granulocytic ehrlichiosis (HGE) is closely related to the veterinary pathogens Erlichia equi and Erlichia... (Comparative Study)
Comparative Study
Homology in the 16S rDNAs shows that the agent of human granulocytic ehrlichiosis (HGE) is closely related to the veterinary pathogens Erlichia equi and Erlichia phagocytophila. After HGE, patients develop antibodies reactive with E. equi and E. phagocytophila; thus, we hypothesized that these species are closely related and share significant antigenicity. Antisera from humans, horses, dogs, and cattle were tested by indirect fluorescent-antibody assay (IFA) for antibodies reactive with E. equi and other ehrlichiae and tested by immunoblot to identify the specific reactions with E. equi. All convalescent-phase sera from human patients with HGE and from animals infected or immunized with E. equi or E. phagocytophila had antibodies reactive with E. equi by IFA; no reactions with Ehrlichia chaffeensis occurred with these sera, and only one horse naturally infected with E. equi had a serologic reaction against Ehrlichia sennetsu. Human and animal sera obtained after infection or immunization with other Ehrlichia, Rickettsia, and Bartonella species did not react with E. equi by IFA. E. equi immunoblots revealed as many as 19 bands with equine anti-E. equi serum. All HGE agent, E. equi, and E. phagocytophila antisera tested reacted with a 44-kDa antigen of E. equi, while other anti-Ehrlichia spp. sera reacted with this antigen rarely or not at all. HGE agent, E. equi, and E. phagocytophila antisera but not other sera also reacted occasionally with 25-, 42-, and 100-kDa antigens. Most sera reacted with antigens between approximately 56 and 75 kDa, probably heat shock proteins. The HGE agent, E. equi, and E. phagocytophila share significant antigenicity by IFA and immunoblot. Coupled with the nearly identical nucleotide sequences of 16S rRNA genes, these data indicate that E. equi, E. phagocytophila, and the human granulocytic ehrlichia are closely related or identical species.
Topics: Animals; Antibodies, Bacterial; Antigens, Bacterial; Cattle; Cross Reactions; Dogs; Ehrlichia; Ehrlichiosis; Fluorescent Antibody Technique; Genes, Bacterial; Granulocytes; Horses; Humans; Mice; Molecular Weight; RNA, Bacterial; RNA, Ribosomal, 16S; Rabbits; Species Specificity
PubMed: 7542262
DOI: 10.1128/jcm.33.5.1098-1103.1995 -
Journal of Veterinary Diagnostic... Jul 2023A validated second-generation SNAP 4Dx Plus (Idexx) incorporates new peptides for improved detection of antibodies against and tick-borne pathogens in dogs. We...
A validated second-generation SNAP 4Dx Plus (Idexx) incorporates new peptides for improved detection of antibodies against and tick-borne pathogens in dogs. We compared the first- and second-generation SNAP 4Dx Plus using dogs naturally infected with or species, or dogs seroreactive by an indirect fluorescent antibody test (IFAT). The second-generation immunoassay was more sensitive than the first-generation for dogs infected with (51.1% and 29.2%, respectively), (63.6% and 35.3%, respectively), (96.2% and 88.3%, respectively), or (73.7% and 70.8%, respectively), and for dogs seroreactive by IFAT (87.3% and 83.9%, respectively). The second-generation immunoassay detected significantly more - or -infected dogs that were ( < 0.001) or ( = 0.031) seroreactive, respectively, than did the first-generation test. When seroreactivity by IFAT and both immunoassays was compared, significantly more -infected dogs were seroreactive by IFAT than the first-generation ( = 0.006) but not the second-generation ( = 0.125) immunoassay. Significantly more -infected dogs were seroreactive by the first- ( = 0.011) and second-generation ( = 0.049) immunoassays than the IFAT. Medical records available for 7 dogs that were seroreactive by the second-generation but not the first-generation immunoassay revealed case management decisions that might have been different with an immediate anaplasmosis diagnosis, including earlier doxycycline therapy and less hospitalization. The second-generation SNAP 4Dx Plus test offered improved serologic detection of and in naturally infected dogs.
Topics: Animals; Dogs; Ehrlichia; Anaplasma; Ehrlichiosis; Point-of-Care Systems; Antibodies, Bacterial; Anaplasmosis; Immunoassay; Polymerase Chain Reaction; Dog Diseases; Ehrlichia canis
PubMed: 37161312
DOI: 10.1177/10406387231172723 -
Parasites & Vectors Mar 2020In the USA, there are several Ehrlichia spp. of concern including Ehrlichia canis, Ehrlichia ewingii, Ehrlichia chaffeensis, Ehrlichia muris eauclarensis, and "Panola...
BACKGROUND
In the USA, there are several Ehrlichia spp. of concern including Ehrlichia canis, Ehrlichia ewingii, Ehrlichia chaffeensis, Ehrlichia muris eauclarensis, and "Panola Mountain Ehrlichia". Of these, E. canis is considered the most clinically relevant for domestic dogs, with infection capable of causing acute, subclinical, and chronic stages of disease. Changes in climate, land use, habitats, and wildlife reservoir populations, and increasing contact between both human and dog populations with natural areas have resulted in the increased risk of vector-borne disease throughout the world.
METHODS
A Bayesian spatio-temporal binomial regression model was applied to serological test results collected from veterinarians throughout the contiguous USA between January 2013 and November 2019. The model was used to quantify both regional and local temporal trends of canine Ehrlichia spp. seroprevalence and identify areas that experienced significant increases in seroprevalence.
RESULTS
Regionally, increasing seroprevalence occurred within several states throughout the central and southeastern states, including Missouri, Arkansas, Mississippi, Alabama, Virginia, North Carolina, Georgia and Texas. The underlying local trends revealed increasing seroprevalence at a finer scale. Clusters of locally increasing seroprevalence were seen from the western Appalachian region into the southern Midwest, along the Atlantic coast in New England, parts of Florida, Illinois, Wisconsin and Minnesota, and in a couple areas of the Mountain region. Clusters of locally decreasing seroprevalence were seen throughout the USA including New York and the mid-Atlantic states, Texas, the Midwest, and California.
CONCLUSIONS
Canine Ehrlichia spp. seroprevalence is increasing in both endemic and non-endemic areas of the USA. The findings from this study indicate that dogs across a wide area of the USA are at risk of exposure and these results should provide veterinarians and pet owners with the information they need to make informed decisions about prevention of tick exposure.
Topics: Animals; Antibodies, Bacterial; Appalachian Region; Bayes Theorem; Dog Diseases; Dogs; Ehrlichia; Ehrlichia canis; Ehrlichia chaffeensis; Ehrlichiosis; Humans; Seroepidemiologic Studies; United States
PubMed: 32228712
DOI: 10.1186/s13071-020-04022-4 -
PloS One 2015One of the major routes of transmission of rickettsial and ehrlichial diseases is via ticks that infest numerous host species, including humans. Besides mammals,...
One of the major routes of transmission of rickettsial and ehrlichial diseases is via ticks that infest numerous host species, including humans. Besides mammals, reptiles and amphibians also carry ticks that may harbor Rickettsia and Ehrlichia strains that are pathogenic to humans. Furthermore, reptiles and amphibians are exempt from quarantine in Japan, thus facilitating the entry of parasites and pathogens to the country through import. Accordingly, in the current study, we examined the presence of Rickettsia and Ehrlichia spp. genes in ticks associated with reptiles and amphibians originating from outside Japan. Ninety-three ticks representing nine tick species (genera Amblyomma and Hyalomma) were isolated from at least 28 animals spanning 10 species and originating from 12 countries (Ghana, Jordan, Madagascar, Panama, Russia, Sri Lanka, Sudan, Suriname, Tanzania, Togo, Uzbekistan, and Zambia). None of the nine tick species are indigenous in Japan. The genes encoding the common rickettsial 17-kDa antigen, citrate synthase (gltA), and outer membrane protein A (ompA) were positively detected in 45.2% (42/93), 40.9% (38/93), and 23.7% (22/93) of the ticks, respectively, by polymerase chain reaction (PCR). The genes encoding ehrlichial heat shock protein (groEL) and major outer membrane protein (omp-1) were PCR-positive in 7.5% (7/93) and 2.2% (2/93) of the ticks, respectively. The p44 gene, which encodes the Anaplasma outer membrane protein, was not detected. Phylogenetic analysis showed that several of the rickettsial and ehrlichial sequences isolated in this study were highly similar to human pathogen genes, including agents not previously detected in Japan. These data demonstrate the global transportation of pathogenic Rickettsia and Ehrlichia through reptile- and amphibian-associated ticks. These imported animals have potential to transfer pathogens into human life. These results highlight the need to control the international transportation of known and potential pathogens carried by ticks in reptiles, amphibians, and other animals, in order to improve national and international public health.
Topics: Amphibians; Animals; Animals, Exotic; Arachnid Vectors; Commerce; DNA, Bacterial; Disease Reservoirs; Ehrlichia; Genes, Bacterial; Introduced Species; Japan; Molecular Sequence Data; Phylogeny; Quarantine; Reptiles; Rickettsia; Sequence Analysis, DNA; Species Specificity; Ticks
PubMed: 26207382
DOI: 10.1371/journal.pone.0133700 -
Antibody reactive immunomes of and are diverse and defined by conformational antigenic determinants.Frontiers in Cellular and Infection... 2023For decades, the defined antibody reactive proteins of and were limited to a small group with linear antibody epitopes. Recently, our laboratory has utilized an...
For decades, the defined antibody reactive proteins of and were limited to a small group with linear antibody epitopes. Recently, our laboratory has utilized an immunomics-based approach to rapidly screen and identify undefined and antigenic proteins and antibody epitopes. In this study, we analyzed the remaining portion (~50%) of the and proteomes ( = 444 and 405 proteins, respectively), that were not examined in previous studies, to define the complete immunomes of these important pathogens. Almost half of the proteins screened (196/444) reacted with antibodies in convalescent HME patient sera, while only 43 proteins reacted with CME dog sera. New major immunoreactive proteins were identified in ( = 7) and ( = 1), increasing the total number of (n = 14) and proteins (n = 18) that exhibited antibody reactivity comparable to well-defined major antigenic proteins (TRP120 and TRP19). All of the but only some major immunoreactive proteins contained major conformation-dependent antibody epitopes. The immunoreactive proteins were generally small (< 250 amino acids; ~27kDa) and the proteins were slightly larger (> 320 amino acids; ~35 kDa). The majority of these new major immunoreactive proteins were predicted to be type I secreted effectors, some of which contained transmembrane domains. Characterization of the immunomes of and and understanding the host specific immune responses will facilitate identification of protective antigens and define the biophysical epitope characteristics vital to effective vaccine development for the ehrlichioses.
Topics: Dogs; Humans; Animals; Ehrlichia chaffeensis; Epitopes; Antibodies; Protein Domains; Transcription Factors; Amino Acids; Hepatitis B e Antigens
PubMed: 38264730
DOI: 10.3389/fcimb.2023.1321291 -
Applied and Environmental Microbiology Jul 2019subsp. is recognized as the etiological agent of human ehrlichiosis in Minnesota and Wisconsin. We describe the culture isolation of this organism from a...
subsp. is recognized as the etiological agent of human ehrlichiosis in Minnesota and Wisconsin. We describe the culture isolation of this organism from a field-collected tick and detail its relationship to other species of The isolate could be grown in a variety of cultured cell lines and was effectively transmitted between ticks and rodents, with PCR and microscopy demonstrating a broad pattern of dissemination in arthropod and mammalian tissues. Conversely, ticks were not susceptible to infection by the Histologic sections further revealed that the wild-type isolate was highly virulent for mice and hamsters, causing severe systemic disease that was frequently lethal. A transposase system was used to create mCherry- and mKate-expressing EmCRT mutants, which retained the ability to infect rodents and ticks. Ehrlichioses are zoonotic diseases caused by intracellular bacteria that are transmitted by ixodid ticks. Here we report the culture isolation of bacteria which are closely related to, or the same as the subsp. , a recently recognized human pathogen. EmCRT, obtained from a tick removed from deer at Camp Ripley, MN, is the second isolate of this subspecies described and is distinctive in that it was cultured directly from a field-collected tick. The isolate's cellular tropism, pathogenic changes caused in rodent tissues, and tick transmission to and from rodents are detailed in this study. We also describe the genetic mutants created from the EmCRT isolate, which are valuable tools for the further study of this intracellular pathogen.
Topics: Animals; Cricetinae; Deer; Ehrlichia; Female; Ixodes; Male; Mice; Mice, Inbred C57BL; Microscopy, Electron, Transmission; Minnesota; Transformation, Genetic
PubMed: 31076433
DOI: 10.1128/AEM.00866-19 -
Ticks and Tick-borne Diseases Mar 2023Ehrlichia are intracellular bacteria of medical importance to both humans and domestic animals. They are mainly vectored by ticks and harbored by domestic and wild...
Ehrlichia are intracellular bacteria of medical importance to both humans and domestic animals. They are mainly vectored by ticks and harbored by domestic and wild animals such as rodents. In this study, we investigated the prevalence and genetic diversity of Ehrlichia in rodents from Inner Mongolia Autonomous Region, Northern China. In 2021, a total of 359 rodents representing 10 species were captured in two locations of Inner Mongolia: Siziwang Banner and Ar Horqin Banner. Subsequently, an Ehrlichia was detected and characterized in three Spermophilus dauricus and one Meriones unguiculatus. Its rrs, gltA, and groEL sequences have the highest identities of 100%, 87.9%, and 99.7% to known Ehrlichia species, respectively, and they form distinct clades in the phylogenetic trees. Ehrlichia strains mostly related to this species have been detected in ticks from Russia, suggesting that it may be exposed to humans and animals through tick bites. The pathogenicity of this Ehrlichia should be further studied.
Topics: Humans; Animals; Ehrlichia; Phylogeny; Sciuridae; Ticks; China
PubMed: 36577306
DOI: 10.1016/j.ttbdis.2022.102116 -
Expert Review of Vaccines Sep 2010Ehrlichia are tick-borne obligately intracellular bacteria that cause significant diseases in veterinary natural hosts, including livestock and companion animals, and... (Review)
Review
Ehrlichia are tick-borne obligately intracellular bacteria that cause significant diseases in veterinary natural hosts, including livestock and companion animals, and are now considered important zoonotic pathogens in humans. Vaccines are needed for these veterinary and zoonotic human pathogens, but many obstacles exist that have impeded their development. These obstacles include understanding genetic and antigenic variability, influence of the host on the pathogen phenotype and immunogenicity, identification of the ehrlichial antigens that stimulate protective immunity and those that elicit immunopathology, development of animal models that faithfully reflect the immune responses of the hosts and understanding molecular host-pathogen interactions involved in immune evasion or that may be blocked by the host immune response. We review the obstacles and progress in addressing barriers associated with vaccine development to protect livestock, companion animals and humans against these host defense-evasive and cell function-manipulative, vector-transmitted pathogens.
Topics: Animals; Antigens, Bacterial; Bacterial Vaccines; Biomedical Research; Disease Models, Animal; Ehrlichia; Ehrlichiosis; Genetic Variation; Host-Pathogen Interactions; Humans; Zoonoses
PubMed: 20822349
DOI: 10.1586/erv.10.93 -
Journal of Medical Entomology Mar 2017Amblyomma maculatum Koch (the Gulf Coast tick) is an aggressive, human-biting ixodid tick distributed throughout much of the southeastern United States and is the...
Amblyomma maculatum Koch (the Gulf Coast tick) is an aggressive, human-biting ixodid tick distributed throughout much of the southeastern United States and is the primary vector for Rickettsia parkeri, an emerging human pathogen. Amblyomma maculatum has diverse host preferences that include white-tailed deer, a known reservoir for Ehrlichia and Anaplasma species, including the human pathogens E. ewingii and E. chaffeensis. To examine more closely the potential role of A. maculatum in the maintenance of various pathogenic Ehrlichia and Anaplasma species, we screened DNA samples from 493 questing adult A. maculatum collected from six U.S. states using broad-range Anaplasmataceae and Ehrlichia genus-specific PCR assays. Of the samples tested, four (0.8%) were positive for DNA of Ehrlichia ewingii, one (0.2%) was positive for Anaplasma platys, and one (0.2%) was positive for a previously unreported Ehrlichia species closely related to Ehrlichia muris and an uncultivated Ehrlichia species from Haemaphysalis longicornis ticks in Japan. No ticks contained DNA of Ehrlichia chaffeensis, Ehrlichia canis, the Panola Mountain Ehrlichia, or Anaplasma phagocytophilum. This is the first identification of E. ewingii, A. platys, and the novel Ehrlichia in questing Gulf Coast ticks; nonetheless the low prevalence of these agents suggests that A. maculatum is not likely an important vector of these zoonotic pathogens.
Topics: Anaplasma; Anaplasmosis; Animals; Deer; Ehrlichia; Ehrlichiosis; Female; Host Specificity; Humans; Ixodidae; Male; Pregnancy
PubMed: 28031351
DOI: 10.1093/jme/tjw176