627 research outputs found

    Letters

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    Differences in Nursery Pigs’ Behavior on the Day of Vaccination

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    Swine industry feed suppliers are continually striving to develop techniques and tools to reduce the additive stressors imposed on the weanling piglet, to increase advantageous behaviors (feeding and drinking) and to reduce aggressive interactions. One product on the market designed to ease the transition from a liquid diet (sow\u27s milk) to a dry ration is a gel-based feed supplement that was incorporated in this trial as a means to positively affect feeding and drinking behaviors. The objectives of this study were to determine if there were differences in the nursery pigs’ behavior on the day of vaccination when provided a gel supplement. A total of 29 d crossbred pigs (5.94 kg) were housed in Double L® confinement nursery buildings. Four treatments were compared. No vaccine and no gel (control n = 4) defined as unvaccinated and without supplemental gel at days 8 to 10. No vaccine and gel (n = 4) defined as pigs that were provided supplemental gel at days 8 to 10 without vaccination. Vaccinated and no gel (n = 4) defined as pigs that were vaccinated but did not receive supplemental gel at days 8 to 10. Vaccinated and gel (n = 4) defined as pigs that were provided supplemental gel at days 8 to 10 and were vaccinated. The group of four pigs housed together in a pen was considered the experimental unit for data analysis. Definitions for the behaviors and postures recorded and summarized for the trial included the following: Active was defined as standing, this included any upright postures. Inactive posture was defined as sitting or lying postures (both lateral and sternal). Time at drinker was defined as when an individual pig’s mouth was around the water nipple. Time at feeding stations was defined as the time when the individual pig’s head was inside the creep (that contained gel) or the three hole feeder (dry pelleted feed). Nursery aged pigs were less active (P \u3c 0.05; Figure 1) and spent less time (P \u3c 0.05; Figure 2) at the feeding stations 1- h after receiving Mycoplasma hyopneumoniae vaccination, indicating a short term behavioral response to this stressor. These behavioral alterations continued for approximately 6- h (or 5:00 PM the vaccination day afternoon). After this time, all nursery pigs regardless of treatment engaged in the same behavioral repertoire. However, the behavioral repertoire of these nursery pigs were not different over the 3-d trial (previously published worked by Johnson et al., 2008) suggesting that the effects of this vaccination stressor and product were not long lasting

    Envelope Determinants of Equine Lentiviral Vaccine Protection

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    Lentiviral envelope (Env) antigenic variation and associated immune evasion present major obstacles to vaccine development. The concept that Env is a critical determinant for vaccine efficacy is well accepted, however defined correlates of protection associated with Env variation have yet to be determined. We reported an attenuated equine infectious anemia virus (EIAV) vaccine study that directly examined the effect of lentiviral Env sequence variation on vaccine efficacy. The study identified a significant, inverse, linear correlation between vaccine efficacy and increasing divergence of the challenge virus Env gp90 protein compared to the vaccine virus gp90. The report demonstrated approximately 100% protection of immunized ponies from disease after challenge by virus with a homologous gp90 (EV0), and roughly 40% protection against challenge by virus (EV13) with a gp90 13% divergent from the vaccine strain. In the current study we examine whether the protection observed when challenging with the EV0 strain could be conferred to animals via chimeric challenge viruses between the EV0 and EV13 strains, allowing for mapping of protection to specific Env sequences. Viruses containing the EV13 proviral backbone and selected domains of the EV0 gp90 were constructed and in vitro and in vivo infectivity examined. Vaccine efficacy studies indicated that homology between the vaccine strain gp90 and the N-terminus of the challenge strain gp90 was capable of inducing immunity that resulted in significantly lower levels of post-challenge virus and significantly delayed the onset of disease. However, a homologous N-terminal region alone inserted in the EV13 backbone could not impart the 100% protection observed with the EV0 strain. Data presented here denote the complicated and potentially contradictory relationship between in vitro virulence and in vivo pathogenicity. The study highlights the importance of structural conformation for immunogens and emphasizes the need for antibody binding, not neutralizing, assays that correlate with vaccine protection. © 2013 Craigo et al

    The impact of the introduction of fidaxomicin on the management of Clostridium difficile infection in seven NHS secondary care hospitals in England: a series of local service evaluations.

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    Clostridium difficile infection (CDI) is associated with high mortality. Reducing incidence is a priority for patients, clinicians, the National Health Service (NHS) and Public Health England alike. In June 2012, fidaxomicin (FDX) was launched for the treatment of adults with CDI. The objective of this evaluation was to collect robust real-world data to understand the effectiveness of FDX in routine practice. In seven hospitals introducing FDX between July 2012 and July 2013, data were collected retrospectively from medical records on CDI episodes occurring 12 months before/after the introduction of FDX. All hospitalised patients aged ≥18 years with primary CDI (diarrhoea with presence of toxin A/B without a previous CDI in the previous 3 months) were included. Recurrence was defined as in-patient diarrhoea re-emergence requiring treatment any time within 3 months after the first episode. Each hospital had a different protocol for the use of FDX. In hospitals A and B, where FDX was used first line for all primary and recurrent episodes, the recurrence rate reduced from 10.6 % to 3.1 % and from 16.3 % to 3.1 %, with a significant difference in 28-day mortality from 18.2 % to 3.1 % (p < 0.05) and 17.3 % to 6.3 % (p < 0.05) for hospitals A and B, respectively. In hospitals using FDX in selected patients only, the changes in recurrence rates and mortality were less marked. The pattern of adoption of FDX appears to affect its impact on CDI outcome, with maximum reduction in recurrence and all-cause mortality where it is used as first-line treatment
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