Experimental infection of pregnant ewes with enteric and abortion-source Chlamydophila abortus

Tsakos, P.; Siarkou, Victoria I.; Guscetti, Franco; Chowdhury, H.; Papaioannou, N.; Vretou, Evangelia; Papadopoulos, O.

doi:10.1016/s0378-1135(01)00389-3

Cited by 9 publications

(6 citation statements)

References 17 publications

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“…Both the cELISA and the rOMP90-4 test appear to be sufficiently sensitive and specific for achieving this aim. It is interesting that in a recent study, when one of the enteric isolates was administered by oronasal inoculation to pregnant ewes, it resulted in abortion (38). Surprisingly, under the experimental conditions used, the enteric isolate was even more virulent than the control abortifacient isolate.…”

Section: Discussionmentioning

confidence: 97%

Serological Diagnosis of Ovine Enzootic Abortion by Enzyme-Linked Immunosorbent Assay with a Recombinant Protein Fragment of the Polymorphic Outer Membrane Protein POMP90 ofChlamydophila abortus

et al. 2002

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Ovine enzootic abortion (OEA) resulting from infection of sheep and goats with Chlamydophila abortus is of major economic importance worldwide. Over the last 50 years the serological diagnosis of infection has been based mainly on the complement fixation test (CFT), which lacks both sensitivity and specificity because of cross-reactive antibodies to other gram-negative bacteria, including another common chlamydial pathogen of sheep, Chlamydophila pecorum. In the present study, a series of overlapping recombinant antigens representing the polymorphic outer membrane protein POMP90 of C. abortus was assessed by enzyme-linked immunosorbent assay (ELISA) with a panel of 143 serum samples from sheep experimentally infected with C. abortus, from sheep clinically free of OEA, and from specific-pathogen-free lambs experimentally infected with different subtypes of C. pecorum. The results were compared to those obtained by CFT and another recently described test, an indirect ELISA (iELISA) with the recombinant OMP91B (rOMP91B) fragment (rOMP91B iELISA) (D. Longbottom, E. Psarrou, M. Livingstone, and E. Vretou, FEMS Microbiol. Lett. 195:157-161, 2001). The rOMP90-3 and rOMP90-4 ELISAs were identified as being more sensitive and specific than CFT. Assays with both fragments were evaluated further with a panel of 294 field serum samples from flocks with documented histories of abortion, from flocks with no clinical histories of abortion but which had a high proportion of samples seropositive by CFT, and from animals with no histories of abortion but from which various C. pecorum subtypes had been isolated. ELISAs with both POMP90 fragments outperformed CFT with serum samples from C. pecorum-infected animals, producing no false-positive results. However, the ELISA with the rOMP90-4 fragment appeared to be more sensitive than the one with rOMP90-3, as it identified more of the OEA-positive samples. The ELISA with the rOMP90-4 fragment was also able to identify apparently healthy animals that were infected with an enteric strain of C. abortus in flocks that were probably infected with both enteric C. abortus and C. pecorum strains. The identification of animals infected with enteric C. abortus is extremely important in controlling the spread of OEA. Overall, the new rOMP90-4 ELISA was found to be a more sensitive and specific test than CFT for differentiating animals infected with C. abortus from those infected with C. pecorum.

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Section: Discussionmentioning

confidence: 97%

Serological Diagnosis of Ovine Enzootic Abortion by Enzyme-Linked Immunosorbent Assay with a Recombinant Protein Fragment of the Polymorphic Outer Membrane Protein POMP90 ofChlamydophila abortus

et al. 2002

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“…An alternative scenario is that the ewes were infected with a less virulent strain of Cp. abortus , which provokes seroconversion but no abortion [ 17 , 20 ]. Fluctuations in the antibody levels could be the result of bacterial shedding during oestrus which provokes an induction of antibody levels without causing abortion [ 21 , 22 ].…”

Section: Discussionmentioning

confidence: 99%

Ovine Enzootic Abortion (OEA): a comparison of antibody responses in vaccinated and naturally-infected swiss sheep over a two year period

Gerber

Thoma²,

Vretou

et al. 2007

BMC Vet Res

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BackgroundPrevention and control of ovine enzootic abortion (OEA) can be achieved by application of a live vaccine. In this study, five sheep flocks with different vaccination and infection status were serologically tested using a competitive enzyme-linked immunosorbent assay (cELISA) specific for Chlamydophila (Cp.) abortus over a two-year time period.ResultsSheep in Flock A with recent OEA history had high antibody values after vaccination similar to Flock C with natural Cp. abortus infections. In contrast, OEA serology negative sheep (Flock E) showed individual animal-specific immunoreactions after vaccination. Antibody levels of vaccinated ewes in Flock B ranged from negative to positive two and three years after vaccination, respectively. Positive antibody values in the negative control Flock D (without OEA or vaccination) are probably due to asymptomatic intestinal infections with Cp. abortus. Excretion of the attenuated strain of Cp. abortus used in the live vaccine through the eye was not observed in vaccinated animals of Flock E.ConclusionThe findings of our study indicate that, using serology, no distinction can be made between vaccinated and naturally infected sheep. As a result, confirmation of a negative OEA status in vaccinated animals by serology cannot be determined.

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“…Diagnosis can be improved by development of methods based on detection of chlamydial antigen by immunofluorescence (Rodolakis et al, 1999), immunohistochemical staining Kunz et al, 1991;Tsakos et al, 2001) or enzyme linked immunosorbent assay (ELISA) Sanderson and Andersen, 1989), which are specific and more sensitive, but require use of sophisticated equipment and are expensive to perform. However, these tests generally do not allow identification of the respective species or serotype involved (Sachse et al, 2009b).…”

Section: Direct Diagnosismentioning

confidence: 99%

Chlamydiaceae and chlamydial infections in sheep or goats

Rodolakis

Laroucau

2015

Veterinary Microbiology

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Experimental infection of pregnant ewes with enteric and abortion-source Chlamydophila abortus

Cited by 9 publications

References 17 publications

Serological Diagnosis of Ovine Enzootic Abortion by Enzyme-Linked Immunosorbent Assay with a Recombinant Protein Fragment of the Polymorphic Outer Membrane Protein POMP90 ofChlamydophila abortus

Serological Diagnosis of Ovine Enzootic Abortion by Enzyme-Linked Immunosorbent Assay with a Recombinant Protein Fragment of the Polymorphic Outer Membrane Protein POMP90 ofChlamydophila abortus

Ovine Enzootic Abortion (OEA): a comparison of antibody responses in vaccinated and naturally-infected swiss sheep over a two year period

Chlamydiaceae and chlamydial infections in sheep or goats

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