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1.
The efficacy of a live 1B vaccine against three strains of Chlamydophila abortus, AB16, LLG and POS, was assessed in pregnant mice in terms of the reduction in the levels of infection recorded in their placentas, fetuses and spleens. The vaccine was more effective against the AB16 strain than against the LLG and POS strains, suggesting that there are antigenic differences between the three strains. 相似文献
2.
Bacteria of the family Chlamydiaceae are obligate intracellular pathogens of human and animals. Chlamydophila pecorum is associated with different pathological conditions in ruminants, swine and koala. To characterize a coding tandem repeat (CTR) identified at the 3' end of incA gene of C. pecorum, 51 strains of different chlamydial species were examined. The CTR were observed in 18 of 18 tested C. pecorum isolates including symptomatic and asymptomatic animals from diverse geographical origins. The CTR were also found in two strains of C. abortus respectively isolated from faeces from a healthy ewe and from a goat belonging to asymptomatic herds, but were absent in C. abortus strains isolated from clinical disease specimens, and in tested strains of C. psittaci, C. caviae, C. felis and C. trachomatis. The number of CTR repeats is variable and encode several motifs that are rich in alanine and proline. The CTR-derived variable structure of incA, which encode the Chlamydiaceae-specific type III secreted inclusion membrane protein, IncA, may be involved in the adaptation of C. pecorum to its environment by allowing it to persist in the host cell. 相似文献
3.
Primers targeting the conserved pmp gene family of Chlamydophila abortus were evaluated for their ability to improve the polymerase chain reaction (PCR) sensitivity. In purified DNA, specific pmp primers (named CpsiA and CpsiB) allowed at least a 10-fold increase of the PCR sensitivity compared to the specific ompA primers for C. abortus, but also for C. psittaci and C. caviae strains. No amplification was observed on C. felis, C. pecorum, C. pneumoniae and Chlamydia trachomatis strains. Tested on contaminated specimens such as genital swabs, the PCR sensitivity observed with CpsiA/CpsiB was also better than with the ompA primers. This study demonstrated that these specific pmp primers could serve as valuable, sensitive and common tools for a specific Chlamydophila diagnosis in ruminant, avian and human diseases. Digestion by AluI of the CpsiA/CpsiB fragments allowed a specific discrimination of the strains in function of their hosts and/or their serotypes. 相似文献
4.
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. 相似文献
5.
F I Wang H Shieh Y K Liao 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(11):1215-1220
This study is to (1) investigate the prevalence of Chlamydophila abortus infection in cows and goats in Taiwan, and (2) compare the genetic properties of Taiwanese isolates with abortion strains from other sources. Approximately 71% of aborted cows and 58% of aborted does had IgG against C. abortus in their sera. The seroprevalence rate in cows may be overestimated, because a certain degree of cross-reactivity with C. pecorum cannot be ruled out. Only 22.7% (from aborted cows) and 33.3% (from aborted dogs) of vaginal swabs that tested positive by polymerase chain reaction led to successful isolation of C. abortus by inoculation into chicken embryos, equivalent to 7.1% and 7.9% of isolation rates, respectively. The major outer membrane protein gene of 15 Taiwanese abortion isolates was compared with that of various strains by restriction fragment length polymorphism (RFLP) and nucleotide sequencing. Restriction enzyme CfoI was able to distinguish Taiwanese ruminant isolates, which have identical RFLP patterns, from C. felis (feline) and C. psittaci (avian) strains. Taiwanese isolates had 98.8-100% homology with known ruminant abortion strains and were phylogenetically closest to bovine LW508 strain. 相似文献
6.
Buendía AJ Cuello F Del Rio L Gallego MC Caro MR Salinas J 《Veterinary microbiology》2001,78(3):229-239
A new commercially available ELISA (ELISAr-Chlamydia) for detecting antibodies against Chlamydophila abortus has been evaluated using sheep field serum samples. The ELISA is based on a recombinant antigen which expresses part of a protein from the 80-90kDa family that is specific to C. abortus. Sera (105) from six flocks with confirmed ovine chlamydial abortion (OEA) outbreaks were used in this study, as well as sera (258) from 18 flocks which had suffered no OEA in the last lambing. The ELISAr-Chlamydia was compared with the complement fixation test (CFT) and with an ELISA using purified C. abortus elementary bodies (ELISA-EB), employing as reference technique a comparative microimmunofluorescence test that differentiates C. abortus infection from Chlamydophila pecorum infection. The results showed that the sensitivity of ELISAr-Chlamydia was 90.9% with a specificity of 85.9%, the sensitivity of CFT was 71.0% with a specificity of 83.6%, while the sensitivity of ELISA-EB was 95.2% and the specificity was 54.2%. Furthermore, ELISAr-Chlamydia was the test with fewer false positives resulting from positive reactivity to C. pecorum, although 15% of the sera positive for C. pecorum but negative for C. abortus antibodies reacted positively. This study demonstrated with field material that ELISAr-Chlamydia provides the most balanced results between sensitivity and specificity, especially in flocks with no clinical OEA but reactivity to C. abortus. 相似文献
7.
Berri M Bernard F Lecu A Ollivet-Courtois F Rodolakis A 《Veterinary microbiology》2004,103(3-4):231-240
Chlamydiosis is a zoonosis with a worldwide distribution. The reservoir of susceptible hosts is large and includes birds and both domestic and wild mammals. Chlamydial infection, determined serologically, seems to be widespread among wild ruminants in the Paris zoo (France). In February 2003, an abortion case was reported within the springbok (Antidorcas marsupialis) herd of the zoo. PCR assay using primers targeting the polymorph membrane protein gene (pmp) family was performed on both vaginal swab and placenta samples revealing the presence of Chlamydophila. The inoculation into chicken embryos of an infected placenta extract led to the successful isolation of a C. abortus strain referred to as ASb1. The omp1 gene coding the major outer membrane protein (momp) and the 16S-23S rRNA spacer region of ASb1 were compared to those of various strains by restriction fragment length polymorphism (RFLP). The RFLP analysis showed that this isolate belonged to Chlamydophila abortus species and is highly related to known domestic ruminant's strains causing abortion. The efficacy of a live vaccine 1B, based on a temperature-sensitive mutant of the ovine abortion reference strain AB7, was tested. Protection-challenge experiments in a mouse model show that the ASb1 strain led to mice abortions and that vaccination with 1B vaccine provided them with effective protection. 相似文献
8.
Amin AS 《Research in veterinary science》2003,74(3):213-217
Chlamydophila abortus-DNA was detected using a touchdown enzyme time-release (TETR)-polymerase chain reaction (PCR) assay as an improved test for sensitive and rapid diagnosis of abortion in small ruminants. Two hundred and fifty two placentae, liver or spleen tissue samples from aborting ewes and goats or aborted lambs and kids in which C. abortus infection was suspected were examined by TETR-PCR and the results were compared with cell culture. Sixty-five tissue samples were found to be TETR-PCR positive while only 56 samples were cell culture-positive. After resolution of discrepant samples with a confirmatory nested PCR assay, TETR-PCR had a sensitivity of 97% and a specificity of 99.5% while culture had a sensitivity of 84.8% and a specificity of 100%. The analytical sensitivity of the TETR-PCR assay was determined with DNA extracted from 4-fold serial dilution of C. abortus B577 culture and found to be 0.25 inclusion-forming unit per PCR. No reduction in the analytical sensitivity was noted when the assay was tested with mouse liver samples spiked with 4-fold serial dilution of C. abortus B577 culture. No target product was amplified when DNA from Chlamydophila pecorum was tested. TETR-PCR used in this study is a practical, rapid, sensitive and specific assay that could be used for the detection of C. abortus in infected tissue samples. We recommend the use of this assay as a supplemental diagnostic tool for detection of C. abortus in infected tissue samples. 相似文献
9.
Ling Y Liu W Clark JR March JB Yang J He C 《Veterinary immunology and immunopathology》2011,144(3-4):389-395
A bacteriophage-delivered DNA vaccine against Chlamydophila abortus was constructed by cloning a eukaryotic cassette containing the ompA gene (which expresses the Major Outer Membrane Protein) into a bacteriophage lambda vector. Four groups, each of 20 BALB/c mice were inoculated separately with the phage vaccine, a conventional DNA vaccine based on the same ompA expression cassette, a live attenuated vaccine (strain 1B) or the empty phage vector. The phage and DNA vaccines and empty phage vector were administered intramuscularly on days 0, 14 and 28; the attenuated vaccine was given once on day 0. Half the animals in each group were challenged on day 42 by intraperitoneal injection of live C. abortus and sacrificed on day 49. Phage-vaccinated mice developed moderate antibody levels against C. abortus and yielded higher levels of IFN-γ and IL-2 compared with the attenuated live vaccine group. Clearance of chlamydiae from spleens was significantly better in the attenuated vaccine group compared with the phage vaccine group, while both groups were significantly superior to the DNA vaccine and control groups (p<0.01). Although levels of protection in the mouse model were lower in phage-vaccinated animals, than in 1B vaccinated animals, phage vaccines offer several other advantages, such as easier handling and safety, potentially cheaper production and no chance of reversion to virulence. Although these are preliminary results in a model system, it is possible that with further optimisation immunization with phage vaccines may provide a novel way to improve protection against C. abortus infection and trials in large animals are currently being initiated. 相似文献
10.
Vretou E Radouani F Psarrou E Kritikos I Xylouri E Mangana O 《Veterinary microbiology》2007,123(1-3):153-161
Two commercial enzyme-linked immunosorbent assays (ELISA), the CHEKIT-CHLAMYDIA which uses inactivated Chlamydophila psittaci antigen, and the Chlamydophila abortus ELISA produced by the Institut Pourquier which uses a recombinant fragment of the 80-90 kDa protein, were evaluated with the objective to determine whether the new ELISAs would perform as improved alternatives to the complement fixation test (CFT) for the serological diagnosis of ovine enzootic abortion (OEA). The results were compared to those obtained by the CFT and the competitive ELISA (cELISA). The tests were assessed with a panel of 17 serum samples from specific pathogen-free (SPF) lambs experimentally infected with various subtypes of Chlamydophila pecorum, with sera from 45 C. abortus-infected pregnant sheep and from 54 sheep free of OEA. The C. abortus ELISA was identified as being more specific and sensitive than the other tests. The 4 assays were evaluated further with 254 sera from flocks with documented OEA, from flocks with no history of abortion and from animals after abortion of unknown cause. The C. abortus ELISA by the Institut Pourquier identified less OEA-positive sera than the other assays though it identified correctly 9 of 10 OEA-positive flocks. The basis of the discordant results is discussed. 相似文献
11.
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. 相似文献
12.
Kaltenboeck B Heinen E Schneider R Wittenbrink MM Schmeer N 《Veterinary microbiology》2009,135(1-2):175-180
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. 相似文献
13.
Knitz JC Hoelzle LE Affolter P Hamburger A Zimmermann K Heinritzi K Wittenbrink MM 《DTW. Deutsche tier?rztliche Wochenschrift》2003,110(9):369-374
A chlamydial vaccine efficacy trial with assessment of the clinical acceptability and serum antibody responses was performed in breeding sows. A BGM cell culture derived vaccine containing 10(8)/ml formalin-inactivated purified elementary bodies (Eb.) in sterile 0.15 M saline was prepared from Chlamydophila (Ch.) abortus strain OCHL03/99 which has been isolated in the herd from a sample of vaginal discharge. Vaccination was performed as a randomised trial with parallel treatment of a vaccinated group (25 sows) and non-vaccinated control group (20 sows). Sows received two 2.0-ml doses of vaccine intramuscularly at a three week interval. Control sows were dosed with sterile 0.15 M saline, accordingly. Serological response to vaccination was measured by ELISA with a total of 204 blood serum samples (114 from the vaccine group; 90 from the control group) using crude chlamydial LPS as the antigen. Compared to the control group, vaccinated sows showed a marked primary and secondary IgG serum antibody response following the two vaccinations. Antibody levels peaked between week 7 and 14 after priming vaccination, declined incrementally until week 27 but remained significantly higher than the corresponding sham-immune control levels and the prevaccination values of the vaccine group (p < 0.05). Western blot analysis of solubilized whole Eb. of Ch. abortus, Ch. pecorum, and Chlamydia (C.) suis with pre- and postvaccination sera confirmed that vaccination induced an antibody response preferentially against a range of 13 chlamydial antigens including the 40 kDa MOMP of Ch. abortus. Clinical side effects consisting of a transient mild local inflammatory reaction at the site of injection were observed in approx. 30% of vaccinated sows. These results provide the basis for further clinical evaluation of the Ch. abortus vaccine to protect sows from chlamydia-induced reproductive disorders. 相似文献
14.
Ortega N Caro MR Buendía AJ Gallego MC Del Río L Martínez CM Nicolas L Cuello F Salinas J 《Research in veterinary science》2007,82(3):314-322
Ovine enzootic abortion (OEA) is caused by Chlamydophila abortus, an intracellular bacterium which acts by infecting the placenta, causing abortion in the last term of gestation. The main prevention strategy against OEA is the vaccination of flocks. An effective vaccine against C. abortus must induce a Th1-like specific immune response, which is characterized by the early production of IFN-gamma and the activation of CD8(+)T cells. Moreover, vaccine effectiveness could be modulated by the functioning of the innate immunity. The purpose of this study was to ascertain how polymorphonuclear neutrophils (PMNs) and NK cells might influence vaccine-induced protection. The live attenuated 1B vaccine and two inactivated experimental vaccines, adjuvated with aluminium hydroxide (AH) or QS-21 (QS), were used in PMN-depleted or NK cell-depleted mice. For PMN depletion, RB6-8C5 monoclonal antibody, which recognizes GR1(+) receptors (Robben, P.M., LaRegina, M., Kuziel, W.A., Sibley, L.D. 2005. Recruitment of Gr-1(+) monocytes is essential for control of acute toxoplasmosis. The Journal of Experimental Medicine 201, 1761-1769.) was used, while for NK cell-depletion the anti-asialo GM1 polyclonal antibody was used. The depletion of PMNs caused 100% mortality in non-vaccinated mice (NV) and 60% mortality in the AH-vaccinated mice by day 10 p.i., while both groups showed a significant increase in their bacterial burden in the liver by day 4 p.i. The depletion of NK cells caused mortality only in the NV group (50% by day 10 p.i.), although this group and the 1B vaccinated mice showed an increased bacterial burden in the liver at day 4 p.i. Our results suggest that the importance of PMNs in inactivated vaccines depends on the adjuvant chosen. The results also demonstrated that the importance of NK cells is greater in live vaccines than in inactivated vaccines. 相似文献
15.
Chlamydophila abortus is the causative agent of abortion in pigs and pregnant women. Seroconversion rates were arranged from 11% to 80% in piglets and sows in China. These very high rates illustrate the scale of the problem in China and highlight the urgent need for the development of a C. abortus vaccine. An efficacious anti-chlamydial vaccine should induce not only strong mucosal and systemic T-helper type 1 (Th1) immune response but also give a humoral response that enhances Th1 activation following infection. In order to evaluate an active immune response of a combination of the major outer membrane protein (MOMP) DNA- and protein-based vaccines, 54 BALB/c mice were randomly assigned to six groups and inoculated intramuscularly with: (i) 100 microg pcDNA::MOMP, (ii) 10 microg r-MOMP, (iii) primed with 100 microg pcDNA::MOMP and boosted with 10 microg r-MOMP, (iv) primed-boosted with a combination of pcDNA::MOMP and r-MOMP simultaneously, (v) live-attenuated 1B vaccine, (vi) 100 microg pcDNA3.1 vector. All animals were vaccinated two times at 14 days intervals. Results showed that mice given DNA and r-MOMP induced higher antibody levels, higher T cells proliferation and an elevated level of chlamydial clearance in spleen, which was equivalent to the clearance of 1B vaccine. Mice administrated the DNA-primed/MOMP-boosted approach elicited moderate antibody levels, less T-lymphocyte proliferation and lower chlamydial clearance as compared with 1B vaccine. Co-immunization with DNA- and r-MOMP vaccine may provide novel ways for active immunization strategy against swine C. abortus. 相似文献
16.
García de la Fuente JN Gutiérrez-Martín CB Ortega N Rodríguez-Ferri EF del Río ML González OR Salinas J 《Veterinary microbiology》2004,100(1-2):65-76
The protective efficacy of two inactivated commercial (A, B) and two new inactivated vaccines (M7, QS) against ovine enzootic abortion was determined in two separate experiments in sheep. Vaccine A contained chlamydiae propagated in chicken embryos, adjuvated with Marcol 82, and vaccine B contained chlamydiae cultured in cell monolayers, adjuvated with aluminium hydroxide. For the preparation of the experimental vaccines, Chlamydophila abortus AB7 strain was cultured in McCoy cells and adjuvated with QS-21 (QS) or Montanide ISA 773 (M7). The ewes were vaccinated twice subcutaneously and challenged at 90 days of gestation. Protection was evaluated by clinical, bacteriological and serological examinations, and compared to two control groups: one of infected but not vaccinated ewes, and another of vaccinated but not infected ewes. The experimental vaccines induced considerably better protection than the two commercial ones. The new vaccine M7 especially showed no abortions, a good antibody response, the highest newborn lamb weights and the lowest level of C. abortus shedding at lambing. 相似文献
17.
Reinhold P Jaeger J Liebler-Tenorio E Berndt A Bachmann R Schubert E Melzer F Elschner M Sachse K 《Veterinary journal (London, England : 1997)》2008,175(2):202-211
To assess long-term effects of naturally occurring infection with Chlamydophila spp. on animal health, 25 calves were grouped according to their chlamydial carrier status and checked for health parameters from 2 to 7 months of age. Monthly PCR testing revealed persistent or frequently recurring infections with Chlamydophila pecorum and Chlamydophila abortus in Group 2 (Chl+, n=13), but not in Group 1 (Chl-, n=12). Despite the absence of any clinical illness, calves in Group 2 showed significantly higher body temperatures (subfebrile), lower bodyweights, reduced serum iron concentrations, lower total haemoglobin and haematocrit values. Counting and flow cytometric differentiation of peripheral white blood cells revealed a general decrease in leukocytes in Group 2. At necropsy, follicular bronchiolitis was found in 10/13 calves in Group 2 but in none of Group 1, and the weight of pharyngeal tonsils was significantly higher in Group 2. In conclusion, naturally occurring infections with Chlamydophila species in calves were found to be associated with chronic effects on animal health at a subclinical level. 相似文献
18.
In order to enhance the quantity and the protective properties of the antibodies induced by DNA vaccination with the heat shock protein dnaK gene of Chlamydophila abortus AB7 as well as to elicit an efficient cellular immune response, we vaccinated mice with a DNA prime followed by a boost with the recombinant DnaK protein. In non-pregnant mice, this strategy induced the same predominance of the IgG2a isotype as DNA immunization alone with a substantial increased antibody level. The induced antibodies had no in vitro neutralizing properties on C. abortus infectivity. Moreover, the proteic boost probably failed to elicit an efficient cellular immune response since the pregnant or non-pregnant mice were not protected against the bacterial challenge. 相似文献
19.
A J Buendía J Sánchez L Del Rio B Garcés M C Gallego M R Caro A Bernabé J Salinas 《Veterinary research》1999,30(5):495-507
CBA/J mice were used in the present study to establish differences between the immune response to three chlamydial strains: AB7 (Chlamydia psittaci wild-type strain), 1B (C. psittaci vaccinal strain) and iB1 (C. pecorum). The evolution of chlamydial infection was evaluated in each strain by studying the clinical signs, the number of bacteria isolated from the spleen and the pathology of the liver. Three aspects of the immune response were then studied: the characterization of the infiltrate of leukocytes in the liver, the percentages of T- and B-cells, macrophages and neutrophils in the spleen, and the presence of cytokines in the serum. Infection followed a different course in the C. psittaci-infected mice; 1B-infected mice showed milder levels in all the parameters analysed than their AB7-infected counterparts. The resolution of infection was earlier in 1B-infected mice and, although the immune response to both strains was Th1-like, a more intense CD8+ T-cell response and an earlier presence of TNF-alpha in serum were observed in this group. C. pecorum infection was controlled mainly by a non-specific immune response, since these mice showed no signs of a systemic specific immune response. Neutrophil depletion experiments showed that these cells play a very limited role in the non-specific response against C. pecorum. 相似文献
20.
Ann-Charlotte Godin Camilla Bj?rkman Stina Englund Karl-Erik Johansson Rauni Niskanen Stefan Alenius 《Acta veterinaria Scandinavica》2008,50(1):39