The Experts below are selected from a list of 180 Experts worldwide ranked by ideXlab platform
Annie Rodolakis - One of the best experts on this subject based on the ideXlab platform.
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2015Co-Authors: Bmc Microbiology, Annie Rodolakis, Abdessalem Rekiki, Mustapha Berri, Karim Sidi BoumedineAbstract:Simultaneous differential detection of Chlamydophila abortus, Chlamydophila Pecorum and Coxiella burnetii from aborted ruminant's clinical samples using multiplex PC
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recombinant 35 kda inclusion membrane protein inca as a candidate antigen for serodiagnosis of Chlamydophila Pecorum
2010Co-Authors: Khalil Yousef Mohamad, Mustapha Berri, Abdessalem Rekiki, Annie RodolakisAbstract:Chlamydophila Pecorum strains are commonly found in the intestine and vaginal mucus of asymptomatic ruminants and may therefore induce a positive serological response when the animals are tested for C. abortus. They have also been associated with different pathological diseases in ruminants, swine and koala. The aim of this study was to identify specific C. Pecorum immunodominant antigens which could be used in ELISA tests allowing to distinguish between animals infected with C. Pecorum and those infected with other chlamydial species. A gene encoding 35-kDa inclusion membrane protein incA of C. Pecorum was isolated by immunoscreening of the C. Pecorum DNA library using ovine anti-C. Pecorum antibodies. The recombinant IncA protein did not react with a murine serum directed against C. abortus but did react with a specific monoclonal antibody of C. Pecorum and toward several ovine serum samples obtained after experimental infection with different C. Pecorum strains. This protein could be a good candidate for specific diagnosis of C. Pecorum infection.
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Recent advances in the understanding of Chlamydophila Pecorum infections, sixteen years after it was named as the fourth species of the Chlamydiaceae family
2010Co-Authors: Khalil Yousef Mohamad, Annie RodolakisAbstract:Chlamydophila Pecorum found in the intestine and vaginal mucus of asymptomatic ruminants has also been associated with different pathological conditions in ruminants, swine and koalas. Some endangered species such as water buffalos and bandicoots have also been found to be infected by C. Pecorum. The persistence of C. Pecorum strains in the intestine and vaginal mucus of ruminants could cause long-term sub-clinical infection affecting the animal's health. C. Pecorum strains present many genetic and antigenic variations, but coding tandem repeats have recently been found in some C. Pecorum genes, allowing C. Pecorum strains isolated from sick animals to be differentiated from those isolated from asymptomatic animals. This review provides an update on C. Pecorum infections in different animal hosts and the implications for animal health. The taxonomy, typing and genetic aspects of C. Pecorum are also reviewed.
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Simultaneous differential detection of Chlamydophila abortus, Chlamydophila Pecorum and Coxiella burnetii from aborted ruminant's clinical samples using multiplex PCR
2009Co-Authors: Mustapha Berri, Abdessalem Rekiki, Karim Sidi Boumedine, Annie RodolakisAbstract:Background Chlamydiosis and Q fever, two zoonosis, are important causes of ruminants' abortion around the world. They are caused respectively by strictly intracellular and Gram negative bacterium Chlamydophila abortus (Cp. abortus ) and Coxiella burnetii (C. burnetii). Chlamydophila Pecorum (Cp. Pecorum) is commonly isolated from the digestive tract of clinically inconspicuous ruminants but the abortive and zoonotic impact of this bacterium is still unknown because Cp. Pecorum is rarely suspected in abortion cases of small ruminants. We have developed a multiplex PCR (m-PCR) for rapid simultaneous differential detection of Cp. abortus , Cp. Pecorum and C. burnetii in clinical samples taken from infected animals. Results Specific PCR primers were designed and a sensitive and specific m-PCR was developed to detect simultaneously, in one tube reaction, three specific fragments of 821, 526 and 687-bp long for Cp. abortus, Cp. Pecorum and C . burnetii respectively. This m-PCR assay was performed on 253 clinical samples taken from infected ruminant's flocks that have showed problems of abortion diseases. Thus, 67 samples were infected by either one of the three pathogens: 16 (13 vaginal swabs and 3 placentas) were positive for Cp. abortus , 2 were positive for Cp. Pecorum (1 vaginal swab and 1 placenta) and 49 samples (33 vaginal swabs, 11 raw milks, 4 faeces and 1 placenta) were positive for C. burnetii . Two vaginal swabs were m-PCR positive of both Cp. abortus and C. burnetii and none of the tested samples was shown to be infected simultaneously with the three pathogens. Conclusion We have successfully developed a rapid multiplex PCR that can detect and differentiate Cp. abortus , Cp. Pecorum and C. burnetii; with a good sensitivity and specificity. The diagnosis of chlamydiosis and Q fever may be greatly simplified and performed at low cost. In addition, the improvement in diagnostic techniques will enhance our knowledge regarding the prevalence and the pathogenetic significance of Q fever and chlamydiosis.
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simultaneous differential detection of Chlamydophila abortus Chlamydophila Pecorum and coxiella burnetii from aborted ruminant s clinical samples using multiplex pcr
2009Co-Authors: Mustapha Berri, Abdessalem Rekiki, Karim Sidi Boumedine, Annie RodolakisAbstract:Background Chlamydiosis and Q fever, two zoonosis, are important causes of ruminants' abortion around the world. They are caused respectively by strictly intracellular and Gram negative bacterium Chlamydophila abortus (Cp. abortus) and Coxiella burnetii (C. burnetii). Chlamydophila Pecorum (Cp. Pecorum) is commonly isolated from the digestive tract of clinically inconspicuous ruminants but the abortive and zoonotic impact of this bacterium is still unknown because Cp. Pecorum is rarely suspected in abortion cases of small ruminants. We have developed a multiplex PCR (m-PCR) for rapid simultaneous differential detection of Cp. abortus, Cp. Pecorum and C. burnetii in clinical samples taken from infected animals.
M M Wittenbrink - One of the best experts on this subject based on the ideXlab platform.
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ompa and antigenic diversity of bovine Chlamydophila Pecorum strains
2009Co-Authors: Bernhard Kaltenboeck, M M Wittenbrink, Ernst Heinen, R Schneider, N SchmeerAbstract:Infections with the intracellular bacterium Chlamydophila (C.) Pecorum are highly prevalent worldwide in cattle. These infections cause significant diseases such as polyarthritis, pneumonia, enteritis, genital infections and fertility disorders, and occasionally sporadic bovine encephalomyelitis. Subclinical respiratory infections of calves with C. Pecorum have been associated with airway obstruction, pulmonary inflammation, and reduced weight gains. This investigation examined four chlamydial strains with biological properties of C. Pecorum isolated from feces of clinically normal cattle, from calves with pneumonia, and from bulls with posthitis. The objective was to characterize the evolutionary relationships of these bovine chlamydial isolates to other chlamydiae by genetic analysis of the ompA gene, and by the immunological cross-reactivities in Western immunoblot analysis. PCR typing of the ompA gene identified these isolates as C. Pecorum. The OmpA-deduced amino acid dissimilarities between these four strains spanned 10-20%. In phylogenetic analysis, the four isolates clustered with C. Pecorum ruminant, porcine, and koala strains of different geographic origins rather than with each other. All four isolates showed different patterns of Western immunoblot reactivity with antiserum against bovine C. Pecorum strain LW63, and, interestingly, no cross-reactivity of the OmpA proteins with the anti-LW613 OmpA antibodies. These data underscore the polyphyletic population structure of C. Pecorum and suggest that the spectrum of C. Pecorum OmpA proteins in a host species can occupy the entire evolutionary bandwidth within C. Pecorum. The variant immunoblot reactivities support the notion of considerable genomic plasticity of C. Pecorum.
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recombinant major outer membrane protein momp of Chlamydophila abortus Chlamydophila Pecorum and chlamydia suis as antigens to distinguish chlamydial species specific antibodies in animal sera
2004Co-Authors: Ludwig E Hoelzle, Katharina Hoelzle, M M WittenbrinkAbstract:Recombinant major outer membrane proteins (rMOMP) of Chlamydophila (Ch.) abortus, Ch. Pecorum, and Chlamydia (C.) suis were used as antigens to distinguish chlamydial species-specific antibodies in (i) immune sera from six rabbits and three pigs raised against native purified elementary bodies, (ii) serum samples from 25 sows vaccinated with Ch. abortus, and (iii) 40 serum samples from four heifers experimentally infected with Ch. abortus. All post-exposition sera contained chlamydial antibodies as confirmed by strong ELISA seroreactivities against the chlamydial LPS. For the rMOMP ELISA mean IgG antibody levels were at least 5.8-fold higher with the particular rMOMP homologous to the chlamydial species used for immunisation or infection than with heterologous rMOMPs (P < 0.001). Preferential rMOMP ELISA reactivities of sera were confirmed by Western blotting. The results suggest that the entire chlamydial rMOMP could provide a species-specific serodiagnostic antigen.
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Recombinant major outer membrane protein (MOMP) of Chlamydophila abortus, Chlamydophila Pecorum, and Chlamydia suis as antigens to distinguish chlamydial species-specific antibodies in animal sera.
2004Co-Authors: Ludwig E Hoelzle, Katharina Hoelzle, M M WittenbrinkAbstract:Recombinant major outer membrane proteins (rMOMP) of Chlamydophila (Ch.) abortus, Ch. Pecorum, and Chlamydia (C.) suis were used as antigens to distinguish chlamydial species-specific antibodies in (i) immune sera from six rabbits and three pigs raised against native purified elementary bodies, (ii) serum samples from 25 sows vaccinated with Ch. abortus, and (iii) 40 serum samples from four heifers experimentally infected with Ch. abortus. All post-exposition sera contained chlamydial antibodies as confirmed by strong ELISA seroreactivities against the chlamydial LPS. For the rMOMP ELISA mean IgG antibody levels were at least 5.8-fold higher with the particular rMOMP homologous to the chlamydial species used for immunisation or infection than with heterologous rMOMPs (P
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expression of the major outer membrane protein momp of Chlamydophila abortus Chlamydophila Pecorum and chlamydia suis in escherichia coli using an arabinose inducible plasmid vector
2003Co-Authors: Ludwig E Hoelzle, Katharina Hoelzle, M M WittenbrinkAbstract:Summary The ompA genes encoding the 40 kDa major outer membrane protein (MOMP) of Chlamydophila (Ch.) abortus, Ch. Pecorum, and Chlamydia (C.) suis were cloned into the arabinose-inducible plasmid vector pBADMycHis, and recombinant MOMPs (rMOMP) from the three chlamydial species were expressed at high levels in Escherichia (E.) coli. The proteins lacking the 22 aa N-terminal signal peptide were expressed as insoluble cytoplasmic inclusion bodies which were readily purified using immobilized metal-affinity chromatography. The rMOMPs including the N-terminal signal peptide were expressed and translocated as a surface-exposed immunoaccessible protein into the outer membrane of E. coli. Transformants expressing this full-length rMOMP were significantly reduced in viability. Purified native elementary bodies (EB) and rMOMPs of the three chlamydial species purified from the E. coli cytoplasm were used for immunization of rabbits. The resulting sera were analysed for their ability to recognize homologous and heterologous rMOMP and native EB. When testing rMOMP antisera against rMOMP and EB antigens, marked cross-reactivities were detected between the three species. Using EB antisera and rMOMPs as antigens, a significant species-specific reactivity was measured.
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Expression of the Major Outer Membrane Protein (MOMP) of Chlamydophila abortus, Chlamydophila Pecorum, and Chlamydia suis in Escherichia coli using an Arabinose‐inducible Plasmid Vector
2003Co-Authors: Ludwig E Hoelzle, Katharina Hoelzle, M M WittenbrinkAbstract:The ompA genes encoding the 40 kDa major outer membrane protein (MOMP) of Chlamydophila (Ch.) abortus, Ch. Pecorum, and Chlamydia (C.) suis were cloned into the arabinose-inducible plasmid vector pBADMycHis, and recombinant MOMPs (rMOMP) from the three chlamydial species were expressed at high levels in Escherichia (E.) coli. The proteins lacking the 22 aa N-terminal signal peptide were expressed as insoluble cytoplasmic inclusion bodies which were readily purified using immobilized metal-affinity chromatography. The rMOMPs including the N-terminal signal peptide were expressed and translocated as a surface-exposed immunoaccessible protein into the outer membrane of E. coli. Transformants expressing this full-length rMOMP were significantly reduced in viability. Purified native elementary bodies (EB) and rMOMPs of the three chlamydial species purified from the E. coli cytoplasm were used for immunization of rabbits. The resulting sera were analysed for their ability to recognize homologous and heterologous rMOMP and native EB. When testing rMOMP antisera against rMOMP and EB antigens, marked cross-reactivities were detected between the three species. Using EB antisera and rMOMPs as antigens, a significant species-specific reactivity was measured.
David Longbottom - One of the best experts on this subject based on the ideXlab platform.
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identification sequencing and molecular analysis of chp4 a novel chlamydiaphage of Chlamydophila abortus belonging to the family microviridae
2011Co-Authors: Michelle Sait, Nick Wheelhouse, Morag Livingstone, Rebecca Graham, Neil F Inglis, David LongbottomAbstract:Members of the family Microviridae have been identified in a number of chlamydial species infecting humans (phage CPAR39 in Chlamydophila pneumoniae), other mammals (φCPG1 in Chlamydophila caviae, Chp2 in Chlamydophila abortus and Chp3 in Chlamydophila Pecorum) and birds (Chp1 in Chlamydophila psittaci). This study describes the identification and genome sequencing of Chp4, an icosahedral, 4530 bp, ssDNA phage in C. abortus. Chp4 is predicted to contain eight ORFs, six of which could be assigned putative functions based on sequence similarity to characterized bacteriophage. Gene order and content were highly conserved amongst chlamydiaphage, with the highest sequence variability occurring in the IN5 and INS variable regions of the VP1 major coat protein, which has been associated with host cell recognition and binding. Phylogenetic analysis of VP1 indicated that Chp4 is a member of the Chlamydiamicrovirus, and is most closely related to phage φCPG1 and CPAR39.
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comparative evaluation of eight serological assays for diagnosing Chlamydophila abortus infection in sheep
2009Co-Authors: Kim Wilson, Morag Livingstone, David LongbottomAbstract:Chlamydophila abortus is one of the principal causes of late-term abortion (enzootic abortion of ewes or EAE) in sheep across Europe. Serological diagnosis of EAE is routinely carried out by the complement fixation test, although the interpretation of results can often be difficult because of cross reaction with Chlamydophila Pecorum, which also commonly infects sheep. The purpose of this study was to evaluate and compare four ELISAs developed at Moredun Research Institute and based on whole C. abortus elementary bodies (EBs), an outer membrane preparation of the whole organism (SolPr) and two recombinant polymorphic outer membrane protein fragments (rOMP90-3 and rOMP90-4), with 3 commercial tests, the CHEKIT® Chlamydophila Abortus, Pourquier® ELISA Chlamydophila abortus and ImmunoComb Ovine Chlamydophila Antibody tests. The tests were evaluated using a panel of 202 sera from experimentally and naturally infected animals, as well as from EAE-free flocks. The EB, SolPr and CHEKIT ELISAs performed similarly to the CFT, all lacking in specificity by cross reacting with sera from C. Pecorum infected animals. The ImmunoComb also lacked specificity with C. Pecorum sera, but also badly cross reacted with sera from EAE-free flocks. The rOMP90-3, rOMP90-4 and Pourquier ELISAs were the most specific, although the Pourquier test appeared less sensitive with sera from naturally infected animals. Overall, the rOMP90-3 ELISA performed the best, with high sensitivity (96.8%) and no cross reaction with sera from C. Pecorum infected animals or from EAE-free flocks (100% specificity) and so would be a suitable alternative to the CFT for the serological diagnosis of EAE.
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serological diagnosis of ovine enzootic abortion by enzyme linked immunosorbent assay with a recombinant protein fragment of the polymorphic outer membrane protein pomp90 of Chlamydophila abortus
2002Co-Authors: David Longbottom, Evangelia Vretou, Evgenia Psarrou, Susan Fairley, Stephanie Chapman, Morag LivingstoneAbstract: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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diagnosis of ovine enzootic abortion using an indirect elisa romp91b ielisa based on a recombinant protein fragment of the polymorphic outer membrane protein pomp91b of Chlamydophila abortus
2001Co-Authors: David Longbottom, Morag Livingstone, Evgenia Psarrou, Evangelia VretouAbstract:Chlamydophila abortus is of major economic importance worldwide as one of the principal causes of abortion in sheep. Serological diagnosis of infection by the complement fixation test (CFT) is complicated by false positive reactions resulting from cross-reactive antibodies to Chlamydophila Pecorum. To improve diagnosis an indirect enzyme-linked immunosorbent assay (iELISA) based on a recombinant protein fragment of the C. abortus polymorphic outer membrane protein POMP91B (rOMP91B iELISA) was assessed using a panel of 281 sera from experimentally and naturally infected sheep. The iELISA performed well, being more sensitive (84.2%) and specific (98.5%) than the CFT. Furthermore, the iELISA was better at differentiating C. abortus- from C. Pecorum-infected animals. The new rOMP91B iELISA test will prove a valuable tool for the routine serodiagnosis of C. abortus infection.
Ludwig E Hoelzle - One of the best experts on this subject based on the ideXlab platform.
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recombinant major outer membrane protein momp of Chlamydophila abortus Chlamydophila Pecorum and chlamydia suis as antigens to distinguish chlamydial species specific antibodies in animal sera
2004Co-Authors: Ludwig E Hoelzle, Katharina Hoelzle, M M WittenbrinkAbstract:Recombinant major outer membrane proteins (rMOMP) of Chlamydophila (Ch.) abortus, Ch. Pecorum, and Chlamydia (C.) suis were used as antigens to distinguish chlamydial species-specific antibodies in (i) immune sera from six rabbits and three pigs raised against native purified elementary bodies, (ii) serum samples from 25 sows vaccinated with Ch. abortus, and (iii) 40 serum samples from four heifers experimentally infected with Ch. abortus. All post-exposition sera contained chlamydial antibodies as confirmed by strong ELISA seroreactivities against the chlamydial LPS. For the rMOMP ELISA mean IgG antibody levels were at least 5.8-fold higher with the particular rMOMP homologous to the chlamydial species used for immunisation or infection than with heterologous rMOMPs (P < 0.001). Preferential rMOMP ELISA reactivities of sera were confirmed by Western blotting. The results suggest that the entire chlamydial rMOMP could provide a species-specific serodiagnostic antigen.
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Recombinant major outer membrane protein (MOMP) of Chlamydophila abortus, Chlamydophila Pecorum, and Chlamydia suis as antigens to distinguish chlamydial species-specific antibodies in animal sera.
2004Co-Authors: Ludwig E Hoelzle, Katharina Hoelzle, M M WittenbrinkAbstract:Recombinant major outer membrane proteins (rMOMP) of Chlamydophila (Ch.) abortus, Ch. Pecorum, and Chlamydia (C.) suis were used as antigens to distinguish chlamydial species-specific antibodies in (i) immune sera from six rabbits and three pigs raised against native purified elementary bodies, (ii) serum samples from 25 sows vaccinated with Ch. abortus, and (iii) 40 serum samples from four heifers experimentally infected with Ch. abortus. All post-exposition sera contained chlamydial antibodies as confirmed by strong ELISA seroreactivities against the chlamydial LPS. For the rMOMP ELISA mean IgG antibody levels were at least 5.8-fold higher with the particular rMOMP homologous to the chlamydial species used for immunisation or infection than with heterologous rMOMPs (P
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expression of the major outer membrane protein momp of Chlamydophila abortus Chlamydophila Pecorum and chlamydia suis in escherichia coli using an arabinose inducible plasmid vector
2003Co-Authors: Ludwig E Hoelzle, Katharina Hoelzle, M M WittenbrinkAbstract:Summary The ompA genes encoding the 40 kDa major outer membrane protein (MOMP) of Chlamydophila (Ch.) abortus, Ch. Pecorum, and Chlamydia (C.) suis were cloned into the arabinose-inducible plasmid vector pBADMycHis, and recombinant MOMPs (rMOMP) from the three chlamydial species were expressed at high levels in Escherichia (E.) coli. The proteins lacking the 22 aa N-terminal signal peptide were expressed as insoluble cytoplasmic inclusion bodies which were readily purified using immobilized metal-affinity chromatography. The rMOMPs including the N-terminal signal peptide were expressed and translocated as a surface-exposed immunoaccessible protein into the outer membrane of E. coli. Transformants expressing this full-length rMOMP were significantly reduced in viability. Purified native elementary bodies (EB) and rMOMPs of the three chlamydial species purified from the E. coli cytoplasm were used for immunization of rabbits. The resulting sera were analysed for their ability to recognize homologous and heterologous rMOMP and native EB. When testing rMOMP antisera against rMOMP and EB antigens, marked cross-reactivities were detected between the three species. Using EB antisera and rMOMPs as antigens, a significant species-specific reactivity was measured.
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Expression of the Major Outer Membrane Protein (MOMP) of Chlamydophila abortus, Chlamydophila Pecorum, and Chlamydia suis in Escherichia coli using an Arabinose‐inducible Plasmid Vector
2003Co-Authors: Ludwig E Hoelzle, Katharina Hoelzle, M M WittenbrinkAbstract:The ompA genes encoding the 40 kDa major outer membrane protein (MOMP) of Chlamydophila (Ch.) abortus, Ch. Pecorum, and Chlamydia (C.) suis were cloned into the arabinose-inducible plasmid vector pBADMycHis, and recombinant MOMPs (rMOMP) from the three chlamydial species were expressed at high levels in Escherichia (E.) coli. The proteins lacking the 22 aa N-terminal signal peptide were expressed as insoluble cytoplasmic inclusion bodies which were readily purified using immobilized metal-affinity chromatography. The rMOMPs including the N-terminal signal peptide were expressed and translocated as a surface-exposed immunoaccessible protein into the outer membrane of E. coli. Transformants expressing this full-length rMOMP were significantly reduced in viability. Purified native elementary bodies (EB) and rMOMPs of the three chlamydial species purified from the E. coli cytoplasm were used for immunization of rabbits. The resulting sera were analysed for their ability to recognize homologous and heterologous rMOMP and native EB. When testing rMOMP antisera against rMOMP and EB antigens, marked cross-reactivities were detected between the three species. Using EB antisera and rMOMPs as antigens, a significant species-specific reactivity was measured.
Morag Livingstone - One of the best experts on this subject based on the ideXlab platform.
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identification sequencing and molecular analysis of chp4 a novel chlamydiaphage of Chlamydophila abortus belonging to the family microviridae
2011Co-Authors: Michelle Sait, Nick Wheelhouse, Morag Livingstone, Rebecca Graham, Neil F Inglis, David LongbottomAbstract:Members of the family Microviridae have been identified in a number of chlamydial species infecting humans (phage CPAR39 in Chlamydophila pneumoniae), other mammals (φCPG1 in Chlamydophila caviae, Chp2 in Chlamydophila abortus and Chp3 in Chlamydophila Pecorum) and birds (Chp1 in Chlamydophila psittaci). This study describes the identification and genome sequencing of Chp4, an icosahedral, 4530 bp, ssDNA phage in C. abortus. Chp4 is predicted to contain eight ORFs, six of which could be assigned putative functions based on sequence similarity to characterized bacteriophage. Gene order and content were highly conserved amongst chlamydiaphage, with the highest sequence variability occurring in the IN5 and INS variable regions of the VP1 major coat protein, which has been associated with host cell recognition and binding. Phylogenetic analysis of VP1 indicated that Chp4 is a member of the Chlamydiamicrovirus, and is most closely related to phage φCPG1 and CPAR39.
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comparative evaluation of eight serological assays for diagnosing Chlamydophila abortus infection in sheep
2009Co-Authors: Kim Wilson, Morag Livingstone, David LongbottomAbstract:Chlamydophila abortus is one of the principal causes of late-term abortion (enzootic abortion of ewes or EAE) in sheep across Europe. Serological diagnosis of EAE is routinely carried out by the complement fixation test, although the interpretation of results can often be difficult because of cross reaction with Chlamydophila Pecorum, which also commonly infects sheep. The purpose of this study was to evaluate and compare four ELISAs developed at Moredun Research Institute and based on whole C. abortus elementary bodies (EBs), an outer membrane preparation of the whole organism (SolPr) and two recombinant polymorphic outer membrane protein fragments (rOMP90-3 and rOMP90-4), with 3 commercial tests, the CHEKIT® Chlamydophila Abortus, Pourquier® ELISA Chlamydophila abortus and ImmunoComb Ovine Chlamydophila Antibody tests. The tests were evaluated using a panel of 202 sera from experimentally and naturally infected animals, as well as from EAE-free flocks. The EB, SolPr and CHEKIT ELISAs performed similarly to the CFT, all lacking in specificity by cross reacting with sera from C. Pecorum infected animals. The ImmunoComb also lacked specificity with C. Pecorum sera, but also badly cross reacted with sera from EAE-free flocks. The rOMP90-3, rOMP90-4 and Pourquier ELISAs were the most specific, although the Pourquier test appeared less sensitive with sera from naturally infected animals. Overall, the rOMP90-3 ELISA performed the best, with high sensitivity (96.8%) and no cross reaction with sera from C. Pecorum infected animals or from EAE-free flocks (100% specificity) and so would be a suitable alternative to the CFT for the serological diagnosis of EAE.
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serological diagnosis of ovine enzootic abortion by enzyme linked immunosorbent assay with a recombinant protein fragment of the polymorphic outer membrane protein pomp90 of Chlamydophila abortus
2002Co-Authors: David Longbottom, Evangelia Vretou, Evgenia Psarrou, Susan Fairley, Stephanie Chapman, Morag LivingstoneAbstract: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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diagnosis of ovine enzootic abortion using an indirect elisa romp91b ielisa based on a recombinant protein fragment of the polymorphic outer membrane protein pomp91b of Chlamydophila abortus
2001Co-Authors: David Longbottom, Morag Livingstone, Evgenia Psarrou, Evangelia VretouAbstract:Chlamydophila abortus is of major economic importance worldwide as one of the principal causes of abortion in sheep. Serological diagnosis of infection by the complement fixation test (CFT) is complicated by false positive reactions resulting from cross-reactive antibodies to Chlamydophila Pecorum. To improve diagnosis an indirect enzyme-linked immunosorbent assay (iELISA) based on a recombinant protein fragment of the C. abortus polymorphic outer membrane protein POMP91B (rOMP91B iELISA) was assessed using a panel of 281 sera from experimentally and naturally infected sheep. The iELISA performed well, being more sensitive (84.2%) and specific (98.5%) than the CFT. Furthermore, the iELISA was better at differentiating C. abortus- from C. Pecorum-infected animals. The new rOMP91B iELISA test will prove a valuable tool for the routine serodiagnosis of C. abortus infection.