1
|
Some MV, Biguezoton AS, Githaka N, Adakal H, Dayo GK, Belem A, Zoungrana S, Stachurski F, Chevillon C. The potential of Rhipicephalus microplus as a vector of Ehrlichia ruminantium in West Africa. Ticks Tick Borne Dis 2023; 14:102117. [PMID: 36603230 DOI: 10.1016/j.ttbdis.2022.102117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 12/21/2022] [Accepted: 12/23/2022] [Indexed: 01/01/2023]
Abstract
Heartwater, or cowdriosis, is a virulent tick-borne rickettsial disease of ruminants caused by Ehrlichia ruminantium, biologically transmitted by Amblyomma species (A. variegatum in West Africa). In West Africa, this bacterium was recently reported to naturally infect the invasive cattle tick, Rhipicephalus microplus (Rm) through trans-ovarian transmission from replete adult females to offspring. A 'sheep-tick-sheep' cycle was set up to determine whether feeding the progeny of these ticks on naïve sheep could lead to infection, and to compare clinical outcomes resulting from this transmission with those observed following infection by the natural A. variegatum (Av) vector. Using local strains of ticks (KIMINI-Rm and KIMINI-Av) and of E. ruminantium (BK242), we recorded, using the PCR technique, the presence of bacterial DNA in ticks (larvae for Av and females for Rm) engorged on sheep inoculated by BK242-infected blood. The bacterial DNA was also detected in the next stages of the lifecycle of R. microplus (eggs and larvae), and in sheep infested either by those R. microplus larvae or by A. variegatum nymphs moulted from larvae engorged on blood-inoculated sheep. Bacterial infection in these sheep was demonstrated by detecting antibodies to E. ruminantium using the MAP1-B ELISA and by isolation of the bacterium on cell culture from blood. The sequences of PCS20 gene detected in ticks and sheep were identical to that of the BK242 strain. Our results confirm that R. microplus can acquire and transmit E. ruminantium to the next stage. However, this transmission resulted in a mild subclinical disease whereas severe clinical disease was observed in sheep infested by A. variegatum infected nymphs, suggesting differences in the tick/bacteria relationship. Future studies will focus on replicating these findings with ticks of different isolates and life stages to determine if R. microplus is playing a role in the epidemiology of heartwater in West Africa. Additionally, studies will investigate whether sheep that are seropositive due to infestation by E. ruminantium-infected R. microplus are subsequently protected against heartwater. Such data will add to our understanding of the possible impact of R. microplus in areas where it has become recently established.
Collapse
Affiliation(s)
- Mireille V Some
- Unité de recherche Maladies à Vecteurs et Biodiversité (UMaVeB), Centre International de Recherche-Développement sur l'Elevage en zone Subhumide (CIRDES), 454 Bobo-Dioulasso 01, Burkina Faso; Institut du Développement Rural (IDR), Université Nazi BONI, 01 BP 1091, Bobo-Dioulasso 01, Burkina Faso
| | - Abel S Biguezoton
- Unité de recherche Maladies à Vecteurs et Biodiversité (UMaVeB), Centre International de Recherche-Développement sur l'Elevage en zone Subhumide (CIRDES), 454 Bobo-Dioulasso 01, Burkina Faso.
| | - Naftaly Githaka
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya, P.O. Box 30709-00100, Nairobi, Kenya
| | - Hassane Adakal
- Département des Sciences et Techniques de l'Elevage (DSTE/FASE), Université Dan Dicko Dan Koulodo, Maradi BP 465, Niger
| | - Guiguigbaza-Kossigan Dayo
- Unité de recherche Maladies à Vecteurs et Biodiversité (UMaVeB), Centre International de Recherche-Développement sur l'Elevage en zone Subhumide (CIRDES), 454 Bobo-Dioulasso 01, Burkina Faso
| | - Adrien Belem
- Institut du Développement Rural (IDR), Université Nazi BONI, 01 BP 1091, Bobo-Dioulasso 01, Burkina Faso
| | - Sébastien Zoungrana
- Unité de recherche Maladies à Vecteurs et Biodiversité (UMaVeB), Centre International de Recherche-Développement sur l'Elevage en zone Subhumide (CIRDES), 454 Bobo-Dioulasso 01, Burkina Faso
| | - Frédéric Stachurski
- CIRAD, UMR ASTRE, Montpellier F-34398, France; ASTRE, Univ Montpellier, CIRAD, INRAE, Montpellier, France
| | - Christine Chevillon
- MIVEGEC (Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle), Univ. Montpellier-CNRS-IRD, Montpellier, France
| |
Collapse
|
2
|
Basit MA, Ijaz M, Khan JA, Ashraf K, Abbas RZ. Molecular Evidence and Hematological Profile of Bovines Naturally Infected with Ehrlichiosis in Southern Punjab, Pakistan. Acta Parasitol 2022; 67:72-78. [PMID: 34138414 DOI: 10.1007/s11686-021-00433-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 06/01/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE Ehrlichiosis is one of the tick-borne diseases, which is not only neglected in Pakistan but only a few reports have been documented throughout the globe. The purpose of this study is to highlight and report the neglected pathogen from bovines in Pakistan. METHODS In this study, the pathogen was detected initially based on microscopy, followed by the molecular confirmation and phylogenetic analysis of the pathogen from bovines from south Punjab, Pakistan. The hematological parameters were also assessed in Ehrlichia positive and negative animals. The information of different disease determinants was analyzed by a logistic regression model on SPSS. RESULTS The study has reported an 11.98% (23/192) prevalence of Ehrlichiosis from bovines. The prevalence was slightly more in cattle (13.5%) as compared to the buffaloes (10.4%). The previous tick's history and tick control methods were proved to be the key factors with the occurrence of the disease. The isolates from Pakistan Ehrlichia spp. Pakistan/31, 36, and 8 clustered with the isolates from the USA, Nicaraguan, France, South Africa, and Uganda. Platelet count, hemoglobin level, and hematocrit were found significantly decreased in Ehrlichia affected animals when compared to the healthy bovines. CONCLUSION This is the first report of ehrlichiosis from bovines in Pakistan and will provide the roadmap for future research.
Collapse
|
3
|
Nair A, Hove P, Liu H, Wang Y, Cino-Ozuna AG, Henningson J, Ganta CK, Ganta RR. Experimental Infection of North American Sheep with Ehrlichia ruminantium. Pathogens 2021; 10:pathogens10040451. [PMID: 33918856 PMCID: PMC8070521 DOI: 10.3390/pathogens10040451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/03/2021] [Accepted: 04/07/2021] [Indexed: 11/16/2022] Open
Abstract
Ehrlichia ruminantium, a tick-borne rickettsial, causes heartwater in ruminants resulting from vascular damage. Severity of heartwater varies greatly in ruminant species and breeds, age of animals and for diverse geographic E. ruminantium strains. E. ruminantium and a tick vector, Amblyomma variegatum, originating from Africa, are well established in certain Caribbean islands two centuries ago. Besides the possibility of introduction of heartwater through African exotic animal importation, presence of the pathogen, and the tick vector in the Caribbean pose a high risk to ruminants in the USA and other western hemisphere countries. Scientific evidence supporting the heartwater threat to nonendemic regions, however, is lacking. We describe the first infection study in sheep reared in the USA with seven E. ruminantium strains. All infected sheep exhibited clinical signs characteristic of subacute to subclinical disease, which included labored breathing, depression, coughing, and nasal discharges. Gross and microscopic lesions consistent with heartwater disease including edema and hemorrhage were observed in several organs. Pathogen-specific IgG antibody response was detected in animals infected with all seven strains, while molecular analysis confirmed the pathogen presence only when infected with in vitro cultures. This is the first infection study demonstrating severe heartwater in sheep reared in North America.
Collapse
Affiliation(s)
- Arathy Nair
- Center of Excellence for Vector-Borne Diseases (CEVBD), Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS 66506, USA; (A.N.); (P.H.); (H.L.); (Y.W.)
| | - Paidashe Hove
- Center of Excellence for Vector-Borne Diseases (CEVBD), Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS 66506, USA; (A.N.); (P.H.); (H.L.); (Y.W.)
- Department of Pathobiology, School of Veterinary Medicine, St. George’s University, Grenada, West Indies
| | - Huitao Liu
- Center of Excellence for Vector-Borne Diseases (CEVBD), Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS 66506, USA; (A.N.); (P.H.); (H.L.); (Y.W.)
| | - Ying Wang
- Center of Excellence for Vector-Borne Diseases (CEVBD), Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS 66506, USA; (A.N.); (P.H.); (H.L.); (Y.W.)
| | - Ada G. Cino-Ozuna
- Kansas State Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA; (A.G.C.-O.); (J.H.); (C.K.G.)
| | - Jamie Henningson
- Kansas State Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA; (A.G.C.-O.); (J.H.); (C.K.G.)
| | - Charan K. Ganta
- Kansas State Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA; (A.G.C.-O.); (J.H.); (C.K.G.)
| | - Roman R. Ganta
- Center of Excellence for Vector-Borne Diseases (CEVBD), Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS 66506, USA; (A.N.); (P.H.); (H.L.); (Y.W.)
- Correspondence:
| |
Collapse
|
4
|
Lin M, Xiong Q, Chung M, Daugherty SC, Nagaraj S, Sengamalay N, Ott S, Godinez A, Tallon LJ, Sadzewicz L, Fraser C, Dunning Hotopp JC, Rikihisa Y. Comparative Analysis of Genome of Ehrlichia sp. HF, a Model Bacterium to Study Fatal Human Ehrlichiosis. BMC Genomics 2021; 22:11. [PMID: 33407096 PMCID: PMC7789307 DOI: 10.1186/s12864-020-07309-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The genus Ehrlichia consists of tick-borne obligatory intracellular bacteria that can cause deadly diseases of medical and agricultural importance. Ehrlichia sp. HF, isolated from Ixodes ovatus ticks in Japan [also referred to as I. ovatus Ehrlichia (IOE) agent], causes acute fatal infection in laboratory mice that resembles acute fatal human monocytic ehrlichiosis caused by Ehrlichia chaffeensis. As there is no small laboratory animal model to study fatal human ehrlichiosis, Ehrlichia sp. HF provides a needed disease model. However, the inability to culture Ehrlichia sp. HF and the lack of genomic information have been a barrier to advance this animal model. In addition, Ehrlichia sp. HF has several designations in the literature as it lacks a taxonomically recognized name. RESULTS We stably cultured Ehrlichia sp. HF in canine histiocytic leukemia DH82 cells from the HF strain-infected mice, and determined its complete genome sequence. Ehrlichia sp. HF has a single double-stranded circular chromosome of 1,148,904 bp, which encodes 866 proteins with a similar metabolic potential as E. chaffeensis. Ehrlichia sp. HF encodes homologs of all virulence factors identified in E. chaffeensis, including 23 paralogs of P28/OMP-1 family outer membrane proteins, type IV secretion system apparatus and effector proteins, two-component systems, ankyrin-repeat proteins, and tandem repeat proteins. Ehrlichia sp. HF is a novel species in the genus Ehrlichia, as demonstrated through whole genome comparisons with six representative Ehrlichia species, subspecies, and strains, using average nucleotide identity, digital DNA-DNA hybridization, and core genome alignment sequence identity. CONCLUSIONS The genome of Ehrlichia sp. HF encodes all known virulence factors found in E. chaffeensis, substantiating it as a model Ehrlichia species to study fatal human ehrlichiosis. Comparisons between Ehrlichia sp. HF and E. chaffeensis will enable identification of in vivo virulence factors that are related to host specificity, disease severity, and host inflammatory responses. We propose to name Ehrlichia sp. HF as Ehrlichia japonica sp. nov. (type strain HF), to denote the geographic region where this bacterium was initially isolated.
Collapse
Affiliation(s)
- Mingqun Lin
- Department of Veterinary Biosciences, The Ohio State University, 1925 Coffey Road, Columbus, OH, 43210, USA.
| | - Qingming Xiong
- Department of Veterinary Biosciences, The Ohio State University, 1925 Coffey Road, Columbus, OH, 43210, USA
| | - Matthew Chung
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 W. Baltimore St, Baltimore, MD, 21201, USA
| | - Sean C Daugherty
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 W. Baltimore St, Baltimore, MD, 21201, USA
| | - Sushma Nagaraj
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 W. Baltimore St, Baltimore, MD, 21201, USA
| | - Naomi Sengamalay
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 W. Baltimore St, Baltimore, MD, 21201, USA
| | - Sandra Ott
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 W. Baltimore St, Baltimore, MD, 21201, USA
| | - Al Godinez
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 W. Baltimore St, Baltimore, MD, 21201, USA
| | - Luke J Tallon
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 W. Baltimore St, Baltimore, MD, 21201, USA
| | - Lisa Sadzewicz
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 W. Baltimore St, Baltimore, MD, 21201, USA
| | - Claire Fraser
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 W. Baltimore St, Baltimore, MD, 21201, USA
- Department of Medicine, University of Maryland School of Medicine, 801 W. Baltimore St, Baltimore, MD, 21201, USA
| | - Julie C Dunning Hotopp
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 W. Baltimore St, Baltimore, MD, 21201, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 801 W. Baltimore St, Baltimore, MD, 21201, USA
- Greenebaum Cancer Center, University of Maryland School of Medicine, 801 W. Baltimore St, Baltimore, MD, 21201, USA
| | - Yasuko Rikihisa
- Department of Veterinary Biosciences, The Ohio State University, 1925 Coffey Road, Columbus, OH, 43210, USA.
| |
Collapse
|
5
|
Anifowose OI, Takeet MI, Talabi AO, Otesile EB. Molecular detection of Ehrlichia ruminantium in engorged ablyomma variegatum and cattle in Ogun State, Nigeria. J Parasit Dis 2020; 44:403-410. [PMID: 32508415 DOI: 10.1007/s12639-020-01218-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Accepted: 03/28/2020] [Indexed: 11/29/2022] Open
Abstract
Early diagnosis of Ehrlichia ruminantium in cattle is a recipe for effective control of heartwater in ruminants. Hence, we assessed the presence of E. ruminantium in the blood of cattle and the engorged Amblyomma variegatum by nested PCR. The electrophoresed PCR products obtained after primary and secondary amplifications revealed amplicon sizes of about350 bp and 280 bp respectively, which corresponded with the partial region of pSC20 gene amplified. Sequences obtained had 95-99% homology with those sequences available in GenBank. The prevalence of the E. ruminantium in ticks (50%; 126/252) was significantly (p < 0.05) higher than that in cattle blood 23.55% (61/259). The prevalence was significantly (p < 0.05) higher in ticks from adult cattle 51.47% (133/259) than those from the young cattle 44.86% (116/259) and in tick from females 54.55% (141/259) than in ticks from the males 41.38% (107/259). Alignment of autochthonous sequences revealed that the three sequences were polymorphic with two sequences showing similar nucleotides deletion at points 87-91 and 107-108. The phylogenetic trees inferred by ML showed topologies with two autochthonous sequences, one each from cattle blood and tick, clustering together in one clade and the other clustering within those sequences from South Africa and Zimbabwe in another clade. In conclusion, this study revealed a higher prevalence of E. ruminantium in engorged A. variegatum than in the blood of infected cattle. Hence, it is suggested that the amplification that targets the pCS20 gene in engorged ticks may be more suitable to determine the E. ruminantium carrier status of cattle.
Collapse
Affiliation(s)
- Olaoluwa Isaac Anifowose
- Department of Veterinary Medicine, College of Veterinary Medicine, Federal University of Agriculture, Abeokuta, Nigeria
| | - Michael Irewole Takeet
- Department of Veterinary Microbiology and Parasitology, College of Veterinary Medicine, Federal University of Agriculture, Abeokuta, Nigeria
| | - Adewale Oladele Talabi
- Department of Veterinary Medicine, College of Veterinary Medicine, Federal University of Agriculture, Abeokuta, Nigeria
| | - Ebenezer Babatunde Otesile
- Department of Veterinary Medicine, College of Veterinary Medicine, Federal University of Agriculture, Abeokuta, Nigeria
| |
Collapse
|
6
|
Peter SG, Gakuya DW, Maingi N, Mulei CM. Prevalence and risk factors associated with Ehrlichia infections in smallholder dairy cattle in Nairobi City County, Kenya. Vet World 2019; 12:1599-1607. [PMID: 31849422 PMCID: PMC6868257 DOI: 10.14202/vetworld.2019.1599-1607] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 09/03/2019] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND AND AIM Ehrlichiosis caused by Ehrlichia ruminantium is a tick-borne disease of great economic importance in cattle production worldwide. Despite its economic impact, limited knowledge is available on its epidemiology in Africa, including Kenya. Suspected cases of E. ruminantium infections have been reported in the recent past to the University of Nairobi's Veterinary Hospital, prompting the need to investigate their possible re-emergence. Therefore, this study was aimed at determining the prevalence of E. ruminantium among smallholder dairy cattle in Nairobi City County and to assess potential risk factors. This knowledge may guide the development of appropriate control strategies of ehrlichiosis, subsequently reducing associated losses. MATERIALS AND METHODS A total of 107 smallholder dairy farms from Nairobi City County were recruited for the study. Blood samples were collected from 314 apparently healthy dairy cattle, and Giemsa-stained blood smears were screened under the microscope for Ehrlichia species. A commercial antigen enzyme-linked immunosorbent assay (ELISA) kit was then used to confirm the presence of the infections in serum samples. A pre-tested questionnaire was used to collect data on management practices that may be potential risk factors. A univariate and mixed-effects logistic regression was then used to determine significant risk factors. RESULTS On microscopy, 79.3% (249/314) of the sampled animals had Ehrlichia-like inclusion bodies in white blood cells, though only 18.6% (95% confidence interval [CI] 14.2-23.0) of these were confirmed to be E. ruminantium on ELISA. A farm-level prevalence of 35.5% (95% CI 27.0-45.3) was reported. Female-headed households (p=0.013), farms in Langata region (p=0.027), cleaning of cowsheds fortnightly (p=0.019), and roofing of cowshed (p=0.022) were factors significantly associated with E. ruminantium infections. CONCLUSION There is a relatively high prevalence of E. ruminantium infections in apparently healthy cattle in smallholder dairy farms in this area, warranting control measures. It is critical to improve animal welfare-related factors, such as cowshed cleaning and roofing, as well as the strategic location of farms, especially, since reservoirs may reduce infection levels in the farms, in relation to wildlife. However, since Ehrlichia-like inclusion bodies other than those of E. ruminantium were observed in this study, there is a need to investigate further these factors and the possibility of other Ehrlichia species infecting cattle in the study area.
Collapse
Affiliation(s)
- Shepelo Getrude Peter
- Department of Clinical Studies, Faculty of Veterinary Medicine, University of Nairobi, Kenya
| | - Daniel Waweru Gakuya
- Department of Clinical Studies, Faculty of Veterinary Medicine, University of Nairobi, Kenya
| | - Ndichu Maingi
- Department of Veterinary Pathology, Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Nairobi, Kenya
| | - Charles Matiku Mulei
- Department of Clinical Studies, Faculty of Veterinary Medicine, University of Nairobi, Kenya
| |
Collapse
|
7
|
Schachat SR, Robbins RG, Goddard J. Color Patterning in Hard Ticks (Acari: Ixodidae). JOURNAL OF MEDICAL ENTOMOLOGY 2018; 55:1-13. [PMID: 29045683 DOI: 10.1093/jme/tjx173] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Indexed: 06/07/2023]
Abstract
Among the hard ticks (Acari: Ixodidae), many species in the section Metastriata have intricate ornamentation on the scutum that is often used as a taxonomic character. However, the biological function(s) of this ornamentation remains unknown. Here, we summarize the main functions of color patterns recognized in the animal kingdom-thermoregulation, aposematism, camouflage, aggregation, mate recognition, and sexual signaling-and evaluate the potential of each of these to explain ornamentation in hard ticks. We also note the challenges and uncertainties involved in interpreting ornamentation in ticks as well as potential approaches for future research.
Collapse
Affiliation(s)
- Sandra R Schachat
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC
| | - Richard G Robbins
- Walter Reed Biosystematics Unit, Department of Entomology, Smithsonian Institution, MSC, Suitland, MD
| | - Jerome Goddard
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS
| |
Collapse
|
8
|
Ehrlichioses: An Important One Health Opportunity. Vet Sci 2016; 3:vetsci3030020. [PMID: 29056728 PMCID: PMC5606584 DOI: 10.3390/vetsci3030020] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/23/2016] [Accepted: 08/25/2016] [Indexed: 12/13/2022] Open
Abstract
Ehrlichioses are caused by obligately intracellular bacteria that are maintained subclinically in a persistently infected vertebrate host and a tick vector. The most severe life-threatening illnesses, such as human monocytotropic ehrlichiosis and heartwater, occur in incidental hosts. Ehrlichia have a developmental cycle involving an infectious, nonreplicating, dense core cell and a noninfectious, replicating reticulate cell. Ehrlichiae secrete proteins that bind to host cytoplasmic proteins and nuclear chromatin, manipulating the host cell environment to their advantage. Severe disease in immunocompetent hosts is mediated in large part by immunologic and inflammatory mechanisms, including overproduction of tumor necrosis factor α (TNF-α), which is produced by CD8 T lymphocytes, and interleukin-10 (IL-10). Immune components that contribute to control of ehrlichial infection include CD4 and CD8 T cells, natural killer (NK) cells, interferon-γ (IFN-γ), IL-12, and antibodies. Some immune components, such as TNF-α, perforin, and CD8 T cells, play both pathogenic and protective roles. In contrast with the immunocompetent host, which may die with few detectable organisms owing to the overly strong immune response, immunodeficient hosts die with overwhelming infection and large quantities of organisms in the tissues. Vaccine development is challenging because of antigenic diversity of E. ruminantium, the necessity of avoiding an immunopathologic response, and incomplete knowledge of the protective antigens.
Collapse
|
9
|
Teshale S, Geysen D, Ameni G, Bogale K, Dorny P, Berkvens D. Molecular detection of Anaplasma species in questing ticks (ixodids) in Ethiopia. ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2016. [DOI: 10.1016/s2222-1808(16)61066-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
10
|
Pompo K, Mays S, Wesselman C, Paulsen DJ, Fryxell RTT. Survey of Ticks Collected from Tennessee Cattle and Their Pastures for Anaplasma and Ehrlichia Species. J Parasitol 2016; 102:54-9. [DOI: 10.1645/15-814] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- K. Pompo
- 370 Plant Biotechnology Building, 2505 E J Chapman Drive, Department of Entomology and Plant Pathology, University of Tennessee Institute of Agriculture, Knoxville, Tennessee 37996-4560
| | - S. Mays
- 370 Plant Biotechnology Building, 2505 E J Chapman Drive, Department of Entomology and Plant Pathology, University of Tennessee Institute of Agriculture, Knoxville, Tennessee 37996-4560
| | - C. Wesselman
- 370 Plant Biotechnology Building, 2505 E J Chapman Drive, Department of Entomology and Plant Pathology, University of Tennessee Institute of Agriculture, Knoxville, Tennessee 37996-4560
| | - D. J. Paulsen
- 370 Plant Biotechnology Building, 2505 E J Chapman Drive, Department of Entomology and Plant Pathology, University of Tennessee Institute of Agriculture, Knoxville, Tennessee 37996-4560
| | - R. T. Trout Fryxell
- 370 Plant Biotechnology Building, 2505 E J Chapman Drive, Department of Entomology and Plant Pathology, University of Tennessee Institute of Agriculture, Knoxville, Tennessee 37996-4560
| |
Collapse
|
11
|
Allen KE, Johnson EM, Little SE. Hepatozoon spp Infections in the United States. Vet Clin North Am Small Anim Pract 2011; 41:1221-38. [DOI: 10.1016/j.cvsm.2011.08.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
12
|
Efficacy of a novel topical combination of fipronil, amitraz and (S)-methoprene for treatment and control of induced infestations with four North American tick species (Dermacentor variabilis, Ixodes scapularis, Amblyomma americanum and Amblyomma maculatum) on dogs. Vet Parasitol 2011; 179:324-9. [DOI: 10.1016/j.vetpar.2011.03.044] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
13
|
Epstein ME, Brainard BM, Mich PM, Carpenter RE, Hawley AT. Postoperative pain management with incisional local anesthetic infiltration. J Am Vet Med Assoc 2010; 237:1017-8; author reply 1018. [PMID: 21034336 DOI: 10.2460/javma.237.9.1017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|