Use of an avirulent live Salmonella Choleraesuis vaccine to reduce the prevalence of Salmonella carrier pigs at slaughter

This study evaluated the use of an avirulent live Salmonella Choleraesuis vaccine to reduce the seroprevalence and number of Salmonella carrier pigs at slaughter. Seven batches of 500 pigs were included in each of the two study groups: the vaccinated group (VG) that was orally vaccinated and the control group (CG) that received a placebo on the first day of life. The groups were managed in a three-site system and followed up from birth to slaughter. Blood samples (n=378) were collected from each VG and CG to monitor the on-farm seroprevalence in both groups. Mesenteric lymph nodes and blood from animals (n=390) belonging to each group were collected at slaughter. At the first day of life, the seroprevalence in control batches ranged from 77.9 to 96.3 per cent, while in vaccinated batches, it ranged from 66.6 to 92.6 per cent. At weaning (21 days of age), the number of seropositives decreased in both groups (mean of 12 and 3.7 per cent for CG and VG, respectively). At slaughter, batches of VG had a significantly (P<0.0001) lower seroprevalence (46.6±5 per cent) and isolation of Salmonella from lymph nodes (33.1±5 per cent) compared with CG batches (79.7±4 per cent and 59.5±5 per cent, respectively). The results indicate that administration of a Salmonella choleraesuis-attenuated vaccine on the first day of life decreases Salmonella isolation and seroprevalence in pigs at slaughter.     

Relationships between trichome types and spider mite (Tetranychus evansi) repellence in tomatoes with respect to foliar zingiberene contents

Zingiberene, a sesquiterpene present in glandular trichomes of Lycopersicon hirsutum Dunal var. hirsutum ‘PI-127826’, is responsible for the high level of arthropod resistance in this taxon. The current paper has the following objectives: (a) to quantify zingiberene content in tomato plants obtained from the interspecific cross L. esculentum Mill. × L. hirsutum var hirsutum; (b) to identify, classify and quantify glandular and non-glandular trichome types present in those plants; (c) to assess the level of resistance of those genotypes to spider mites (Tetranychus evansi); (d) to estimate correlations between glandular trichomes, zingiberene contents and mite repellence. Zingiberene content were quantified by a colorimetric method (Freitas, 1999); trichomes were counted from foliar paradermic slide preparations; mite resistance was assessed by a repellence test (Weston & Snyder, 1990). The results indicate that indirect selection for zingiberene content led to correlated increases both in the number of glandular trichomes (particulary type IV) and in the levels of mite repellence. These results were found both in BPX-368 [=F2 (L. esculentum ‘TOM-556’ × L hirsutum var. hirsutum ‘PI-127826’)] and in the subsequent generation BPX-368B (which represents one additional backcross to L.esculentum). Zingiberene appears therefore to be the main factor involved in mite repellence. Density of glandular trichomes in tomato leaflets markedly influences total zingiberene content. Type IV trichome density was the highest, and it was highly correlated to zingiberene content. Graduate Student; This revised version was published online in August 2006 with corrections to the Cover Date.     

A synthetic conjugate polysaccharide vaccine against Haemophilus influenzae type b

Glycoconjugate vaccines provide effective prophylaxis against bacterial infections. To date, however, no commercial vaccine has been available in which the key carbohydrate antigens are produced synthetically. We describe the large-scale synthesis, pharmaceutical development, and clinical evaluation of a conjugate vaccine composed of a synthetic capsular polysaccharide antigen of Haemophilus influenzae type b (Hib). The vaccine was evaluated in clinical trials in Cuba and showed long-term protective antibody titers that compared favorably to licensed products prepared with the Hib polysaccharide extracted from bacteria. This demonstrates that access to synthetic complex carbohydrate-based vaccines is feasible and provides a basis for further development of similar approaches for other human pathogens.     

Cardiorespiratory,sedative and antinociceptive effects of dexmedetomidine alone or in combination with methadone,morphine or tramadol in dogs

ObjectiveTo evaluate the cardiorespiratory, sedative and antinociceptive effects of dexmedetomidine alone or in combination with methadone, morphine or tramadol in dogs.Study designExperimental, blinded, randomized, crossover study.AnimalsSix mixed breed dogs (two males and four females) weighing 10 ± 4 kg.MethodsThe animals were randomly divided into four treatments: D (10 μg kg^?1 of dexmedetomidine), DM (dexmedetomidine 10 μg kg^?1 and methadone 0.5 mg kg^?1); DMO (dexmedetomidine 10 μg kg^?1 and morphine 0.5 mg kg^?1), and DT (dexmedetomidine 10 μg kg^?1 and tramadol 2 mg kg^?1). The combinations were administered intramuscularly in all treatments. The variables evaluated were heart rate (HR), respiratory rate (f_R), rectal temperature (RT), systolic arterial pressure (SAP), sedation scale and pedal withdrawal reflex. These variables were measured at T0 (immediately before the administration of the protocol) and every 15 minutes thereafter until T105.ResultsA decrease in HR and f_R occurred in all the treatments compared with T0, but no significant difference was observed between the treatments. The RT decreased from T45 onward in all the treatments. The SAP did not show a difference between the treatments, but in the DT treatment, the SAP was lower at T30 and T45 compared with T0. The D treatment had lower scores of sedation at T15 to T75 compared with the other treatments, and the DMO and DM treatments showed higher scores at T60 and T75 compared with DT.Conclusions and clinical relevanceThe treatments with morphine and methadone added to the dexmedetomidine showed higher sedation scores than the control treatment and the treatment with tramadol added to the dexmedetomidine showed no relevant differences in any of the variables evaluated in the study.     

Increased atmospheric carbon dioxide concentration: effects on eucalypt rust (Puccinia psidii), C:N ratio and essential oils in eucalypt clonal plantlets

Evaluation of impacts of high CO₂ atmospheric concentration is strategically important for the development of adaptation measures and sustainable crop management. The objective of this study was to evaluate the effects of increased atmospheric CO₂ concentration on eucalypt rust (Puccinia psidii), C:N ratio, yield and chemical composition of essential oils and growth of eucalypt clonal plantlets. Two clones with different levels of rust resistance were studied: a Eucalyptus urophylla × E. camaldulensis hybrid (VM 01) and an E. urophylla (clone MN 463). The experiments were performed in open‐top chambers (OTCs) with CO₂ mean concentrations (μmol mol^?1) of 399 (unenclosed control), 412 (OTCs with ambient CO₂ concentration) and 508 (OTCs with high CO₂ concentration) and in closed chambers (CCs) with CO₂ mean concentrations of 390, 405, 520 and 700. Increased atmospheric CO₂ concentrations resulted in a decrease in rust pustules per leaf, uredinia per leaf area, spores per uredinia and area under the disease progress curve in VM 01 (hybrid) clonal plantlets. The disease did not occur in MN 463 clonal plantlets, which demonstrated that high CO₂ concentrations did not change the level of rust resistance. Plant growth of the two clones was stimulated by up to 23% in height and 26% in stem diameter in OTCs and by 18% for both clones in CCs. An increased C:N ratio in leaves, stems and roots was observed only for the VM 01 clonal plantlets. Essential oils produced by VM 01 (2.8 g 100 g^?1) and MN 463 (1.4 g 100 g^?1), as well as the major essential oil compounds (80% 1.8‐cineole for VM 01; 50% 1.8‐cineole and 32% α‐pinene for MN 463), were not altered. In this study, increased concentrations of atmospheric CO₂ favourably impacted eucalypt growth and reduced rust severity, while not influencing the production of essential oils.     

Chitosan as a biocontrol agent against the pinewood nematode (Bursaphelenchus xylophilus)

The pine wilt disease (PWD) is caused by Bursaphelenchus xylophilus and poses great environmental and economic challenges. Thus, the development of sustainable techniques for the control of this epidemic disease is of major importance. This work aimed at evaluating if the application of different molecular weight (MW) chitosans as a soil amendment could be used to control the PWD in maritime pine (Pinus pinaster, very susceptible to the disease) and stone pine (Pinus pinea, less susceptible). At the end of the experimental period (24 days after inoculation), P. pinaster and P. pinea untreated plants presented ca. 3825 ± 100 and 70 ± 47 nematodes, respectively. In P. pinaster, the high‐MW chitosan prompted the most drastic results, inducing a 21.9‐fold reduction in nematodes numbers, whereas in P. pinea, the most effective was the low MW chitosan, which reduced nematodes numbers up to 7‐fold, compared with untreated plants. P. pinea seems to be highly resistant to the disease, presenting nematode numbers up to 54.6‐fold lower than P. pinaster and less severe chlorophyll loss (ca. 2‐fold).     

Polymorphisms in the MTRN1A gene and their effects on the productive and reproductive traits in buffaloes

The main environmental factor that affects the regulation of reproductive seasonality is photoperiod through its effects on melatonin secretion. The melatonin receptor MTRN1A appears to be involved in regulating the reproductive seasonality and milk production in the period. The aim of this study was to identify polymorphisms in the MTRN1A gene and their possible associations with milk, fat and protein productions, fat and protein percentages, age at first calving, and first calving interval in buffaloes. Three genotypes (CC, CT, and TT) were identified by PCR-RFLP, and there was a significant association with protein percentage (P?<?0.0001). Further studies are necessary to better understand the influence of melatonin gene and their receptors in the productive functions of buffaloes.     

Rice Germination and Its Impact on Technological and Nutritional Properties: A Review

Grain germination is a process involving numerous factors that influence the biochemical processes inside the plant cells. This review covered the abiotic factors that lead to the germination and significantly impact the nutritional properties and digestion behavior of rice grains. The macro- and micro-nutrients can be changed depending on the intensity of the applied variables during germination. For instance, germination time can increase the protein content in the grain and concurrently reduce its protein digestibility. In most cases, the number of bioactive compounds present in rice grains are increased regardless of germination conditions. Germination can promote the complexation of nutrients and thus negatively interfere with the digestibility of macronutrients. This review highlighted the influence of the germination process on the nutritional quality of rice grains, providing information about the germination conditions and their impacts on the anabolic and catabolic reactions of the grain, emphasizing the health benefits.