Evaluation of protective and immune responses following vaccination with recombinant MIP and CPAF from Chlamydia abortus as novel vaccines for enzootic abortion of ewes.

MIP and CPAF from Chlamydia have been shown to be effective in inducing immune responses important in clearing chlamydial infections. This study evaluates the protection conferred by MIP and CPAF as novel vaccines in pregnant C. abortus challenged ewes. Fifty C. abortus sero-negative sheep were randomly allocated into 5 groups of 10 according to the treatment they were to receive (1) 100 µg of MBP-MIP (2) 100 µg CPAF (3) 50 µg MBP-MIP and 50 µg CPAF (4) Tris-buffer (negative control) (5) Enzovax (positive control). Booster inoculations were administered 3 weeks after primary inoculations. Blood samples were taken pre-vaccination and weekly for 5 weeks. Five months after vaccination the ewes were mated. Pregnant ewes were then challenged on day 90 of gestation. Blood samples taken at four time-points post challenge were analysed for IFNγ levels, TNFα and IL-10 expression and anti-chlamydial antibody levels. Vaginal swabs, placental and foetal tissue and bacterial shedding were analysed using qPCR to quantify levels of C. abortus. Enzovax was 100% effective with no abortions occurring. The MIP/CPAF combined vaccine offered the greatest protection of the novel vaccines with 67% of ewes giving birth to one or more live lambs equating to a 50% vaccine efficacy rate. MIP and CPAF administered singly did not confer protection. Enzovax and MIP/CPAF vaccinated ewes had longer gestations and lambs with higher birth weights than negative control ewes. Aborting ewes shed higher numbers of C. abortus than ewes that had live lambs, all vaccinated ewes demonstrated lower levels of bacterial shedding than negative control ewes with Enzovax ewes shedding significantly fewer bacteria. Ewes that went on to abort had significantly higher levels of IFNγ and IL-10 at day 35 post challenge and significantly higher levels of anti-chlamydial antibodies at 24 h post lambing compared to ewes that had live lambs.

Comparison of three commercial serological tests for the detection of Chlamydia abortus infection in ewes.

BACKGROUND: 20.9% of diagnosable abortions in Ireland in 2015 were caused by Chlamydia abortus infection. Abortion usually occurs in the last 2-3 weeks of gestation, and up to 30% of ewes may be affected in naïve flocks. Serological diagnosis of EAE in flocks using LPS or whole bacteria as antigens is often hindered by cross reactions with C. pecorum. Although the complement fixation test is the official test for diagnosis of EAE, more sensitive and specific ELISA based tests have been developed. This study aimed to compare three commercial ELISA kits to detect C. abortus antibodies in ewes and to determine which of the kits had the highest sensitivity. The IDvet kit utilises a MOMP peptide antigen, the MVD-Enfer kit is based on a POMP90-3 antigen while the LSI kit plates are coated with chlamydial LPS. The study also aimed to examine the potential of these ELISAs to distinguish infected animals that go on to abort compared to those that have live lambs. Ewes were vaccinated with either a commercial live vaccine (n = 10) or Tris-buffer sham inoculation (n = 9) 5 months prior to gestation, these ewes were then challenged with C. abortus (1 × 106 IFU/ml) on day 90 of gestation. Sera were collected at pre-vaccination, 14 days post vaccination, 35 days post vaccination, pre-challenge, 35 days post challenge and 3 weeks post lambing/abortion (~ 70 days post challenge) and tested using the 3 aforementioned ELISAs to determine if one ELISA was more sensitive at detecting circulating anti-chlamydial antibodies. RESULTS: Sensitivity was highest with the LSI test kit at 94.74%, followed by the MVD-Enfer and IDvet kits, at 78.95 and 73.68% respectively. Ewes vaccinated with Enzovax became seropositive at 14 days post vaccination with all kits. Following challenge at day 90 of gestation, antibody titres steadily rose in all groups of ewes. With all ELISA kits, antibody levels were higher in ewes that aborted compared to ewes that had live lambs at 35 days post challenge and three weeks post lambing, and statistically significantly higher antibody levels were recorded in ewes that aborted compared to ewes that had live lambs using the MVD-ENFER ELISA at three weeks post lambing (P = 0.0482). CONCLUSIONS: The LSI assay was the most sensitive out of the three kits tested in this study, when sera were tested at three weeks post lambing. As the LPS used in this kit is cross-reactive with all chlamydia, it is good for identifying flocks infected with any chlamydial species, but it is not considered specific for C. abortus. Furthermore, antibody levels were higher in ewes that aborted compared to ewes that had live lambs, at both 35 days post challenge and at three weeks post lambing. Future work should include evaluation of a larger number of sera at a wider range of time-points as well as an estimation of the specificity of commercially available assays.

Plasma levels of thrombin-antithrombin complexes predict preterm premature rupture of the fetal membranes.

OBJECTIVE: Decidual hemorrhage (abruption) is strongly associated with preterm premature rupture of fetal membranes (PPROM). Moreover, thrombin enhances decidual matrix metalloproteinase (MMP) expression, and MMP has been strongly linked to PPROM. The current study sought to determine whether increased thrombin activation, as assessed by circulating maternal plasma thrombin-antithrombin (TAT) complexes, predicted subsequent PPROM. STUDY DESIGN: We conducted a nested, case-control study of plasma TAT levels, measured by sensitive immunoassay, among 27 women with a singleton preterm birth preceded by PPROM and 54 matched, term controls. Receiver operating characteristic curve analysis was performed to identify the optimal TAT cut-off level predicting PPROM. RESULTS: Mean gestational age at delivery in cases was 33.3 weeks, compared to 39.7 weeks in controls (p < 0.001). Compared with controls, women with PPROM had increased median plasma TAT levels in both the second trimester (5.1 microg/l (range 2.2-26.3 microg/l) vs. 3.2 microg/l (range 1.3-7.3 microg/l); p = 0.001) and third trimester (7.0 microg/l (range 2.6-85.8 microg/dl) vs. 4.8 microg/l (range 1.7-15.4 microg/dl); p = 0.01). In the PPROM group, 16.0% of the women exhibited bleeding during the pregnancy, while the corresponding value among controls was 3.6% (p = 0.07). In the second trimester, the odds ratio for PPROM with a TAT level of > 3.9 microg/l was 6.0 (95% CI 1.67-21.1). This value predicted PPROM with a sensitivity of 88%, specificity of 68% and positive and negative predictive values of 82% and 97%, respectively. CONCLUSION: Second-trimester elevated plasma TAT concentrations are predictive of subsequent PPROM. These data provide further evidence that PPROM is associated with decidual thrombin activation.

A corticotropin releasing hormone receptor antagonist does not delay parturition in rats.

OBJECTIVE: To determine the effects of CP-154, 526, a corticotropin releasing hormone (CRH) receptor antagonist, on the length of normal rat gestation. STUDY DESIGN: Twenty-four timed-pregnant Sprague-Dawley rats were purchased for this study. The drug and placebo were administered to the animals using an osmotic pump surgically inserted in the dorsal subcutaneous space. Six animals received 6 mg/kg/day of the drug, six animals received 12 mg/kg/day of the drug and twelve animals received the placebo. The gestational period, weight of each pup and number of pups in each litter were recorded and compared in the drug group versus placebo group. RESULTS: No difference was noted in the gestational period of the drug and placebo rats. The mean weight of pups in both the drug and placebo groups was 6.18 g. The number of pups per litter were similar in the drug and placebo groups. CONCLUSION: Antagonism of CRH receptors in rats has no effect on the length of gestational period, pup weight or number of pups per litter. Further studies are needed to define the role of CRH and its antagonism in primate pregnancy, as has been done in sheep.

Effect of carnosine, salt and dietary vitamin E on the oxidative stability of chicken meat.

The effect of carnosine on lipid and cholesterol oxidation in salted chicken thigh meat and its relationship to dietary α-tocopherol supplementation was examined. Broilers (Cobb 500) were fed diets with a basal (30 mg kg(-1)) or supplemental (200 mg kg(-1)) level of α-tocopheryl acetate for 6 weeks. Thigh meat patties were prepared with carnosine (1.5%), salt (1%) or salt plus carnosine. Salt accelerated lipid and cholesterol oxidation following cooking and refrigerated storage. However, carnosine inhibited lipid and cholesterol oxidation in salted patties. Dietary α-tocopherol supplementation also reduced the extent of lipid and cholesterol oxidation in salted patties. The combination of carnosine and dietary α-tocopherol resulted in the greatest lipid and cholesterol stability in salted meat.

Comparison of effects of dietary olive oil, tallow and vitamin E on the quality of broiler meat and meat products.

1. The effect of dietary fat and vitamin E supplementation on quality attributes (drip loss, oxidative stability, sensory quality) in chicken meat and meat products was investigated. Broiler chicks were fed on diets containing tallow (60 g/kg) or olive oil (60 g/kg) at a basal (30 mg/kg diet) or supplemental (200 mg/kg diet) concentration of alpha-tocopheryl acetate for 8 weeks. The alpha-tocopherol content and fatty acid composition of breast and thigh meat was determined. Drip loss was determined in breast fillets. Lipid oxidation (thiobarbituric acid-reacting substances/TBARS) and sensory quality (warmed-over flavour development/WOF) were assessed in minced thigh meat during storage. 2. Dietary olive oil increased the ratio of monounsaturated to saturated fatty acids (MUFA/SFA) in the diets. In breast and thigh, this resulted in approximately a two-fold increase in the MUFA/SFA ratio. Supplemental alpha-tocopherol increased the alpha-tocopherol content of muscles. 3. Dietary fat not influence drip loss in thawed breast fillets during refrigerated storage, but supplemental alpha-tocopherol reduced drip loss. 4. TBARS and WOF development in minced thigh meat patties were also reduced by supplemental alpha-tocopherol following frozen storage, or cooking and refrigerated storage. Storage stability was not adversely affected by dietary fat. 5. Overall, the results showed that increasing the monounsaturated profile of chicken meat lipids did not adversely affect quality characteristics. Dietary alpha-tocopherol supplementation was a more important factor in the determination of broiler meat quality.

Inhibition of Lipid Oxidation in Chicken by Carnosine and Dietary α-Tocopherol Supplementation and its Determination by Derivative Spectrophotometry.

The antioxidant activity of carnosine in chicken meat, and its relationship to dietary α-tocopherol supplementation, was examined. Broiler chickens were fed diets containing 30 (basal) or 200 (supplemental) mg α-tocopherol acetate kg(-1) feed for 6 weeks. Raw and cooked thigh meat patties containing carnosine (0-1·5%) were prepared. Lipid oxidation, during refrigerated storage under fluorescent light, was assessed by monitoring malonaldehyde formation, using the TBA assay and single wavelength (conventional) or first derivative spectrophotometry. In raw patties, added carnosine improved oxidative stability for up to 10 days of refrigerated storage. In cooked patties, the 1·5% carnosine level provided the best antioxidant protection during 7 days of storage. Carnosine (1·5%) was at least as effective as supplemental α-tocopherol in improving the oxidative stability of raw and cooked patties. The presence of both antioxidants had an additive effect on oxidative stability. Overall, the use of derivative spectrophotometry improved the specificity of the TBA assay for monitoring MDA formation in refrigerated meats.

Use of pelvic tilt exercise for ligament pain relief.

The purpose of this study was to test the effectiveness of a pelvic (hip) tilt exercise in relieving ligament pain during pregnancy. A multiple pain measurement approach was used. The intensity of ligament pain was decreased as indicated by scores on three of four pain intensity measures. The duration of ligament pain also was reduced, although not significantly. Mean scores on all measures of ligament pain intensity, duration, and frequency were lower after the exercises were initiated. Verbal reports from subjects indicated that they had received effective pain relief from the exercise. Thus, pelvic (hip) tilt exercise appears to be effective in reducing ligament pain intensity and, to a lesser extent, pain duration. As a nurse-midwifery strategy, this exercise promotes patient/client comfort and facilitates self-care in the relief of ligament pain during pregnancy.