Development of a Polyclonal Competitive Enzyme-Linked Immunosorbent Assay for Detection of Antibodies to
            <i>Ehrlichia ruminantium</i>

Sumption, Keith; Paxton, Edith; Bell‐Sakyi, Lesley

doi:10.1128/cdli.10.5.910-916.2003

Cited by 9 publications

(15 citation statements)

References 28 publications

(15 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The higher seroprevalence in sheep could also be an indication that local dwarf sheep are more tolerant of E. ruminantium infection than dwarf goats or merely that sheep are more frequently infested with A. variegatum ticks than goats. A longitudinal study in Ghana of E. ruminantium seropositivity using a competitive ELISA (20) with sensitivity comparable to that of the MAP1-B ELISA (4) revealed high antibody levels detectable for longer periods in sheep than in goats (3). Therefore, it is also possible that the higher seroprevalence in sheep could be due to longer persistence of antibodies.…”

Section: Discussionmentioning

confidence: 99%

Point Seroprevalence Survey ofEhrlichia ruminantiumInfection in Small Ruminants in The Gambia

Faburay

Münstermann

Geysen

et al. 2005

Clin Vaccine Immunol

Self Cite

View full text Add to dashboard Cite

Using the MAP1-B enzyme-linked immunosorbent assay, we tested 1,318 serum samples collected from sheep and goats at 28 sites in the five divisions of The Gambia to determine the Ehrlichia ruminantium seroprevalence rates and to assess the risk for heartwater. About half (51.6%) of 639 sheep were positive, with seroprevalence rates per site varying between 6.9% and 100%. The highest seroprevalence was detected in the western part of the country (88.1% in the Western Division and 62.1% in the Lower River Division). Sheep in the two easterly divisions (Central River and Upper River divisions) showed the lowest seroprevalence of 29.3% and 32.4%, respectively, while those in the North Bank Division showed an intermediate prevalence of 40.6%. In goats, less than one-third (30.3%) of 679 animals tested were positive. The highest seroprevalence was detected in goats in the North Bank Division (59%) and Western Division (44.1%). Goats in the Lower River Division showed an intermediate level of 21.9%, whereas the lowest rates were found in the eastern part of the country (4.8% in the Central River Division and 2.3% in the Upper River Division). At nearly all sites, seroprevalence rates were higher in sheep than in goats. The results show a gradient of increasing heartwater risk for susceptible small ruminants from the east to the west of The Gambia. These findings need to be taken into consideration when future livestock-upgrading programs are implemented.

show abstract

Section: Discussionmentioning

confidence: 99%

Point Seroprevalence Survey ofEhrlichia ruminantiumInfection in Small Ruminants in The Gambia

Faburay

Münstermann

Geysen

et al. 2005

Clin Vaccine Immunol

Self Cite

View full text Add to dashboard Cite

show abstract

“…MAP1-B ELISA was employed in the above studies. Koney et al (2004) in Ghana used the polyclonal competitive ELISA (PC-ELISA) of Sumption et al (2003) and found seroprevalences of 51% in sheep and 28% in goats. Using a modified version of the PC-ELISA, Awa (1997) found seroprevalences of 58-66% in sheep and 65-66% in goats in northern Cameroon.…”

Section: Discussionmentioning

confidence: 99%

Serological survey of antibodies to Ehrlichia ruminantium in small ruminants in Tanzania

Swai¹,

Moshy²,

Mtui³

et al. 2008

Trop Anim Health Prod

View full text Add to dashboard Cite

Sera from 497 sheep and 555 goats collected in a cross sectional study from different geographical locations in north-eastern Tanzania were examined for antibodies to Ehrlichia ruminantium using MAP 1-B ELISA technique. E. ruminantium antibodies were found in 68.6% (341/497) of sheep and 64.7% (359/555) of goats. Overall seroprevalence was 66.5% (700/1052). Infection rates were higher in sheep than goats (P < 0.05), in pastoral than in agro-pastoral production systems (P < 0.05) and in female sheep than males (P < 0.05). (131/143) 91.6% of the farms/flocks tested revealed sero-positive animals. E.ruminantium infections were found in all the geographical villages and districts tested. The infection rates per administrative district varied from 36.4% (Muheza) to 90% (Mkinga) in goats and from 11.9% (Muheza) to 94.6% (Mkinga) in sheep. The results shows E. ruminantium infection was prevalent and widely but unevenly distributed throughout the eight districts under study. These findings should be taken into consideration when future disease control and livestock upgrading programs are implemented.

show abstract

“…PI levels of Ͼ85 for sheep sera and Ͼ70 for cattle sera were considered to indicate positivity for E. ruminantium (35).…”

Section: Methodsmentioning

confidence: 99%

“…Indirect ELISA protocols using crude elementary body-derived antigen (26,34) and a monoclonal antibody-based competitive ELISA (17) resulted in cross-reactions with other ovine and bovine Ehrlichia species (12,16). Recently, a new competitive ELISA, which uses crude, detergent-solubilized elementary body antigen and polyclonal biotinylated competitor antibody (polyclonal competitive ELISA [PC-ELISA]), has been reported to have reduced cross-reactivity with other ruminant Ehrlichia species and improved sensitivity compared to crude antigenbased indirect ELISAs (35). Serological tests utilizing recombinant antigens include an indirect ELISA based on a specific fragment of the E. ruminantium major antigenic protein (MAP1), the MAP1-B ELISA (38), and a competitive ELISA using recombinant MAP1 antigen and anti-MAP1 monoclonal antibody competitor (18).…”

mentioning

confidence: 99%

“…As part of an epidemiological survey of the incidence and prevalence of heartwater in domestic ruminants in the West African country of Ghana, serum samples were collected monthly or on single occasions from sheep and cattle and tested for antibodies to E. ruminantium by using the PC-ELISA (35). Based on postmortem diagnosis, heartwater was reported to occur throughout Ghana (2).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Detection by Two Enzyme-Linked Immunosorbent Assays of Antibodies toEhrlichia ruminantiumin Field Sera Collected from Sheep and Cattle in Ghana

Bell‐Sakyi

Koney

Dogbey

et al. 2003

Clin Vaccine Immunol

Self Cite

View full text Add to dashboard Cite

Two serological tests for detection of antibodies to Ehrlichia (previously Cowdria) ruminantium, the causative agent of heartwater, were compared by using field sera collected from sheep and cattle as part of serosurveys in Ghana. Sera selected as either negative or positive by a new polyclonal competitive enzyme-linked immunosorbent assay (PC-ELISA) were tested by the indirect MAP1-B ELISA. Cutoff values of 14 percent positivity (14 PP) for both ruminant species were obtained for the MAP1-B ELISA by using preseroconversion Ghanaian sera and were compared with previously recommended cutoff values of 29 PP for sheep and 38 PP for cattle. With the 14-PP cutoff, of 151 sheep sera which tested negative by PC-ELISA, 89% were also negative by MAP1-B ELISA, while of 419 sheep sera positive by PC-ELISA, 98% were also positive by MAP1-B ELISA. Of 261 bovine sera negative by PC-ELISA, 82% were also negative by MAP1-B ELISA. Of 511 bovine sera positive by PC-ELISA, only 47% were positive by MAP1-B ELISA; these included 168 sera collected from cattle following first seroconversion as detected by both tests, with 125 of these sera positive by PC-ELISA but only 59 and 5 positive by MAP1-B ELISA with the 14-and 38-PP cutoff levels, respectively. These results indicate that both assays are highly sensitive and specific for detection of E. ruminantium exposure in sheep but that the MAP1-B ELISA lacks sensitivity for postseroconversion bovine sera in comparison to the PC-ELISA. Both tests confirm E. ruminantium seroprevalence of at least 70% in Ghanaian sheep; levels of exposure among Amblyomma variegatum-infested Ghanaian cattle are likely to be higher than the seroprevalence value of 66% obtained with the PC-ELISA.Heartwater, or cowdriosis, caused by the rickettsia Ehrlichia (previously Cowdria) ruminantium (10) and transmitted by ticks of the genus Amblyomma, is an often fatal disease of susceptible domestic ruminants in sub-Saharan Africa and some Caribbean islands (7). Epidemiological surveys of E. ruminantium prevalence in areas of endemicity have been limited by the lack of suitably sensitive and specific serodiagnostic tests (15). Fluorescent antibody tests based on E. ruminantiuminfected mouse macrophages (11), neutrophils and bovine endothelial cell cultures (27), and immunoblotting assays (20, 25) lacked specificity (12,16,25) and were too labor-intensive for mass screening. Several enzyme-linked immunosorbent assay (ELISA) systems have been developed over the last decade, with progressive improvement in performance. Indirect ELISA protocols using crude elementary body-derived antigen (26, 34) and a monoclonal antibody-based competitive ELISA (17) resulted in cross-reactions with other ovine and bovine Ehrlichia species (12,16

show abstract

Development of a Polyclonal Competitive Enzyme-Linked Immunosorbent Assay for Detection of Antibodies to Ehrlichia ruminantium

Cited by 9 publications

References 28 publications

Point Seroprevalence Survey ofEhrlichia ruminantiumInfection in Small Ruminants in The Gambia

Point Seroprevalence Survey ofEhrlichia ruminantiumInfection in Small Ruminants in The Gambia

Serological survey of antibodies to Ehrlichia ruminantium in small ruminants in Tanzania

Detection by Two Enzyme-Linked Immunosorbent Assays of Antibodies toEhrlichia ruminantiumin Field Sera Collected from Sheep and Cattle in Ghana

Contact Info

Product

Resources

About