scholarly journals Serologic Cross-Reactivity between Anaplasma marginale and Anaplasma phagocytophilum

2005 ◽  
Vol 12 (10) ◽  
pp. 1177-1183 ◽  
Author(s):  
U. M. Dreher ◽  
J. de la Fuente ◽  
R. Hofmann-Lehmann ◽  
M. L. Meli ◽  
N. Pusterla ◽  
...  

ABSTRACT In the context of a serosurvey conducted on the Anaplasma marginale prevalence in Swiss cattle, we suspected that a serological cross-reactivity between A. marginale and A. phagocytophilum might exist. In the present study we demonstrate that cattle, sheep and horses experimentally infected with A. phagocytophilum not only develop antibodies to A. phagocytophilum (detected by immunofluorescent-antibody assay) but also to A. marginale (detected by a competitive enzyme-linked immunosorbent assay). Conversely, calves experimentally infected with A. marginale also developed antibodies to A. phagocytophilum using the same serological tests. The identity of 63% determined in silico within a 209-amino-acid sequence of major surface protein 5 of an isolate of A. marginale and one of A. phagocytophilum supported the observed immunological cross-reactivity. These observations have important consequences for the serotesting of both, A. marginale and A. phagocytophilum infection of several animal species. In view of these new findings, tests that have been considered specific for either infection must be interpreted carefully.

2007 ◽  
Vol 14 (3) ◽  
pp. 262-268 ◽  
Author(s):  
N. I. Strik ◽  
A. R. Alleman ◽  
A. F. Barbet ◽  
H. L. Sorenson ◽  
H. L. Wamsley ◽  
...  

ABSTRACT Major surface protein 5 (Msp5) of Anaplasma marginale is highly conserved in the genus Anaplasma and the antigen used in a commercially available competitive enzyme-linked immunosorbent assay (cELISA) for serologic identification of cattle with anaplasmosis. This study analyzes the degrees of conservation of Msp5 among various isolates of Anaplasma phagocytophilum and the extent of serologic cross-reactivity between recombinant Msp5 (rMsp5) of Anaplasma marginale and A. phagocytophilum. The msp5 genes from various isolates of A. phagocytophilum were sequenced and compared. rMsp5 proteins of A. phagocytophilum and A. marginale were used separately in an indirect ELISA to detect cross-reactivity in serum samples from humans and dogs infected with A. phagocytophilum and cattle infected with A. marginale. Serum samples were also tested with a commercially available competitive ELISA that uses monoclonal antibody ANAF16C1. There were 100% sequence identities in the msp5 genes among all of the A. phagocytophilum isolates from the United States and a horse isolate from Sweden. Sheep isolates from Norway and dog isolates from Sweden were 99% identical to one another but differed in 17 base pairs from the United States isolates and the horse isolate. Serologic cross-reactivity was identified when serum samples from cattle infected with A. marginale were reacted with rMsp5 of A. phagocytophilum and when serum samples from humans and dogs infected with A. phagocytophilum were reacted with rMsp5 of A. marginale in an indirect-ELISA format. Serum samples from dogs or humans infected with A. phagocytophilum did not cross-react with rMsp5 of A. marginale when tested with the commercially available cELISA. These results suggest that rMsp5 of A. phagocytophilum is highly conserved among United States and European isolates and that serologic distinction between A. phagocytophilum and A. marginale infections cannot be accomplished if rMsp5 from either organism is used in an indirect ELISA.


1998 ◽  
Vol 36 (3) ◽  
pp. 777-782 ◽  
Author(s):  
Susana Torioni de Echaide ◽  
Donald P. Knowles ◽  
Travis C. McGuire ◽  
Guy H. Palmer ◽  
Carlos E. Suarez ◽  
...  

A competitive enzyme-linked immunosorbent assay using recombinant major surface protein 5 (rMSP5-cELISA) of Anaplasma marginale was validated in a naturally infected cattle herd in an area of eastern Oregon where A. marginale is endemic. The true positive and negative A. marginale infection status of 235 randomly selected cattle was determined by using a nested PCR (nPCR) coupled with msp5 sequence analysis and hybridization. Judgment of the reliability of the nPCR and hybridization for detection of persistent infections was based on three observations. First, the nPCR was able to detect as few as 30 infected erythrocytes per ml. Second, the nPCR was able to consistently detect low levels of rickettsemia in seven carrier cattle experimentally infected with A. marginale. Third, msp5sequence analysis showed >95% identity among 30 nPCR amplicons from cattle naturally infected with field strains of A. marginale. The nPCR and hybridization identified 151 infected and 84 uninfected cattle among the 235 animals tested. With a cutoff point of 28%, the rMSP5-cELISA showed a sensitivity of 96% and a specificity of 95%. These results indicate that the rMSP5-cELISA can sensitively and specifically detect cattle with naturally acquired persistent A. marginale infections and suggest that it is an excellent assay for epidemiological studies, eradication programs, and regulation of international cattle movement.


2011 ◽  
Vol 23 (6) ◽  
pp. 1181-1188 ◽  
Author(s):  
Batol Al-Adhami ◽  
W. Brad Scandrett ◽  
Vladislav A. Lobanov ◽  
Alvin A. Gajadhar

Seroconversion and cross-reactivity in cattle infected with Anaplasma marginale or a recently described Ehrlichia species (BOV2010 from British Columbia, Canada) were investigated. The study used 76 samples from 20 animals, a commercially available competitive enzyme-linked immunosorbent assay (cELISA) for bovine anaplasmosis, and an indirect fluorescent antibody test (IFAT). Blood smear examination and/or polymerase chain reaction assay were performed to confirm or rule out the presence of Anaplasma or Ehrlichia. Samples comprised 3 groups. Group 1 consisted of 24 samples from 9 cattle naturally infected with Ehrlichia sp. BOV2010. Group 2 had 13 samples from 3 A. marginale–infected cattle from Manitoba, Canada. Group 3 had 39 samples, consisting of 26 from 5 calves experimentally infected with Ehrlichia sp. BOV2010, 10 from 2 calves experimentally infected with A. marginale from cattle (Manitoba) or bison (Saskatchewan), and 3 from an uninfected calf. All samples from cattle naturally or experimentally infected with Ehrlichia sp. BOV2010 or A. marginale were seropositive for A. marginale by both cELISA and IFAT, except 3 calves euthanized at 28 and 33 days post-inoculation (DPI) that did not seroconvert. Antibodies were detected in 2 experimental animals inoculated with Ehrlichia sp. BOV2010, as early as 28 and 33 DPI by the cELISA and IFAT, respectively, and by 42 DPI for both tests. The current study demonstrates that the specificity of the recombinant major surface protein 5 (MSP5) antigen is not restricted to Anaplasma spp., which reduces the utility of the test for serological diagnosis of bovine anaplasmosis in regions where Ehrlichia sp. BOV2010–infected cattle might exist.


2004 ◽  
Vol 72 (12) ◽  
pp. 7360-7366 ◽  
Author(s):  
Jeffrey R. Abbott ◽  
Guy H. Palmer ◽  
Chris J. Howard ◽  
Jayne C. Hope ◽  
Wendy C. Brown

ABSTRACT Organisms in the genus Anaplasma express an immunodominant major surface protein 2 (MSP2), composed of a central hypervariable region (HVR) flanked by highly conserved regions. Throughout Anaplasma marginale infection, recombination results in the sequential appearance of novel MSP2 variants and subsequent control of rickettsemia by the immune response, leading to persistent infection. To determine whether immune evasion and selection for variant organisms is associated with a predominant response against HVR epitopes, T-cell and linear B-cell epitopes were localized by measuring peripheral blood gamma interferon-secreting cells, proliferation, and antibody binding to 27 overlapping peptides spanning MSP2 in 16 cattle. Similar numbers of MSP2-specific CD4+ T-cell epitopes eliciting responses of similar magnitude were found in conserved and hypervariable regions. T-cell epitope clusters recognized by the majority of animals were identified in the HVR (amino acids [aa] 171 to 229) and conserved regions (aa 101 to 170 and 272 to 361). In contrast, linear B-cell epitopes were concentrated in the HVR, residing within hydrophilic sequences. The pattern of recognition of epitope clusters by T cells and of HVR epitopes by B cells is consistent with the influence of protein structure on epitope recognition.


2006 ◽  
Vol 101 (5) ◽  
pp. 511-516 ◽  
Author(s):  
Virgínia MG Silva ◽  
Flábio R Araújo ◽  
Claudio R Madruga ◽  
Cleber O Soares ◽  
Raul H Kessler ◽  
...  

2002 ◽  
Vol 88 (3) ◽  
pp. 275-285 ◽  
Author(s):  
José de la Fuente ◽  
Ronald A Van Den Bussche ◽  
Jose C Garcia-Garcia ◽  
Sergio D Rodrı́guez ◽  
Miguel A Garcı́a ◽  
...  

2000 ◽  
Vol 68 (1) ◽  
pp. 270-280 ◽  
Author(s):  
Wenbin Tuo ◽  
Guy H. Palmer ◽  
Travis C. McGuire ◽  
Daming Zhu ◽  
Wendy C. Brown

ABSTRACT Anaplasma marginale is a tick-transmitted pathogen of cattle closely related to the human ehrlichiae, Ehrlichia chaffeensis and the agent of human granulocytic ehrlichiosis (HGE). These pathogens have in common a structurally conserved outer membrane protein (OMP) designated the major surface protein 2 (MSP-2) in A. marginale and HGE and OMP-1 in E. chaffeensis. Protective immunity against ehrlichial pathogens is believed to require induction of gamma interferon (IFN-γ) and opsonizing immunoglobulin (Ig) subclasses directed against OMP epitopes that, in concert, activate macrophages for phagocytosis and killing. Because interleukin-12 (IL-12) acts as an adjuvant for protein immunization to induce IFN-γ and protective immunity against intracellular pathogens, we hypothesized that as an adjuvant with MSP-2, IL-12 would augment type 1 recall responses to A. marginale. IL-12 was coadsorbed with MSP-2 to alum and shown to significantly enhance IFN-γ production by lymph node cells (LNC) and LNC-derived CD4+ T-cell lines from immunized calves following recall stimulation with A. marginale. LNC proliferation and IL-2 production were also enhanced in IL-12-treated calves. Elevated recall proliferative responses by peripheral blood mononuclear cells were still evident 9 months after immunization. Serum IgG levels were consistently increased in IL-12 immunized calves, predominantly due to higher IgG1 responses. The results support the use of IL-12 coadsorbed with OMP of ehrlichial pathogens in alum to amplify both antibody and type-1 cytokine responses important for protective immunity.


Sign in / Sign up

Export Citation Format

Share Document