Safety of a modified-live combination vaccine against respiratory and reproductive diseases in pregnant cows

A combination vaccine (Bovi-Shield FP4 + L5, Pfizer Animal Health) containing modified-live virus (MLV) components against bovine herpesvirus-1 (BHV-1), bovine viral diarrhea virus BVDV), parainfluenza virus-3 (PI3), bovine respiratory syncytial virus (BRSV), and inactivated cultures of Leptospira canicola, grippotyphosa, hardjo, icterohaemorrhagiae, and pomona was evaluated for safety in pregnant beef and dairy animals. Heifers vaccinated prebreeding with the minimum immunizing dose (lowest antigen level initiating immunizing effects) of the vaccine's MLV BHV-1 or BVDV components and during pregnancy (approximately 200 days of gestation) with vaccine containing 10x doses of the same BHV-1 and BVDV components delivered live, healthy calves that were determined to be serologically negative (titer less than 1:2) for neutralizing antibodies to BHV-1 and BVDV prior to nursing. Additionally, in three field safety studies, previously vaccinated cows and heifers that received a field dose (vaccine containing antigen levels required for commercial sale of the MLV combination vaccine during either the first, second, or third trimester of pregnancy had abortion rates similar to those of pregnant cows and heifers vaccinated during the same stage of pregnancy with sterile water diluent.     

Evaluation of protective immunity in pigs following oral administration of an avirulent live vaccine of Lawsonia intracellularis

OBJECTIVE: To evaluate the efficacy of an orally administered avirulent live vaccine to protect pigs against challenge exposure with virulent Lawsonia intracellularis. ANIMALS: 108 weaned 3-week-old pigs (35 in experiment 1 and 73 in experiment 2). PROCEDURE: 2 experiments were conducted. On day 0, vaccinates were orally administered vaccine via drench or in drinking water, whereas challenge-control pigs were administered cultured medium. On day 21, pigs were challenge exposed with a virulent heterologous isolate of L. intracellularis. Clinical observations, weights, seroconversion, and fecal excretion of L. intracellularis were measured until day 42. At study termination, pigs were euthanatized and examined for L. intracellularis-specific lesion development of the ileum and colon. RESULTS: Pigs receiving a single dose of vaccine were protected when challenge exposed with virulent L. intracellularis (at least 10(77) TCID50/dose). In experiment 1, vaccinates had significantly less fecal excretion (47% and 40% for days 35 and 42, respectively), compared with challenge-control pigs. In experiment 2, vaccinates had significantly less fecal excretion (50% and 58% for days 35 and 42, respectively), compared with challenge-control pigs. Significant reductions in lesion development were evident in the ileum of vaccinated pigs (70% and 56% at day 42 for experiments 1 and 2, respectively), compared with challenge-control pigs. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration by drench or via drinking water of an avirulent live vaccine against L. intracellularis resulted in substantial protection against proliferative enteropathy among vaccinates and offers a better way to reduce stress of pigs during vaccine administration.     

Estimating the spatial scales of landscape effects on abundance

Context

Spatial variation in abundance is influenced by local- and landscape-level environmental variables, but modeling landscape effects is challenging because the spatial scales of the relationships are unknown. Current approaches involve buffering survey locations with polygons of various sizes and using model selection to identify the best scale. The buffering approach does not acknowledge that the influence of surrounding landscape features should diminish with distance, and it does not yield an estimate of the unknown scale parameters.

Objectives

The purpose of this paper is to present an approach that allows for statistical inference about the scales at which landscape variables affect abundance.

Methods

Our method uses smoothing kernels to average landscape variables around focal sites and uses maximum likelihood to estimate the scale parameters of the kernels and the effects of the smoothed variables on abundance. We assessed model performance using a simulation study and an avian point count dataset.

Results

The simulation study demonstrated that estimators are unbiased and produce correct confidence interval coverage except in the rare case in which there is little spatial autocorrelation in the landscape variable. Canada warbler abundance was more highly correlated with site-level measures of NDVI than landscape-level NDVI, but the reverse was true for elevation. Canada warbler abundance was highest when elevation in the surrounding landscape, defined by an estimated Gaussian kernel, was between 1300 and 1400 m.

Conclusions

Our method provides a rigorous way of formally estimating the scales at which landscape variables affect abundance, and it can be embedded within most classes of statistical models.

     

Relating tradable credits for biodiversity to sustainability criteria in a dynamic landscape

Tradable biodiversity credit systems provide flexible means to resolve conflicts between development and conservation land-use options for habitats occupied by threatened or endangered species. We describe an approach to incorporate the influence of habitat fragmentation into the conservation value of tradable credits. Habitat fragmentation decreases gene flow, increases rates of genetic drift and inbreeding, and increases probabilities of patch extinction. Importantly, tradable credit systems will change the level of fragmentation over time for small and/or declining populations. We apply landscape equivalency analysis (LEA), a generalizable, landscape-scale accounting system that assigns conservation value to habitat patches based on patch contributions to abundance and genetic variance at landscape scales. By evaluating habitat trades using two models that vary the relationship between dispersal behaviors and landscape patterns, we show that LEA provides a novel method for limiting access to habitat at the landscape-scale, recognizing that the appropriate amount of migration needed to supplement patch recruitment and to offset drift and inbreeding will vary as landscape pattern changes over time. We also found that decisions based on probabilities of persistence alone would ignore changes in migration, genetic drift, and patch extinction that result from habitat trades. The general principle of LEA is that habitat patches traded should make at least equivalent contributions to rates of recruitment and migration estimated at a landscape scale. Traditional approaches for assessing the “take” and “jeopardy” standards under the Endangered Species Act based on changes in abundance and probability of persistence may be inadequate to prevent trades that increase fragmentation.     

Effect of induced unilateral synovitis of distal intertarsal and tarsometatarsal joints on sagittal plane kinematics and kinetics of trotting horses

OBJECTIVE: To study the effect of unilateral synovitis in the distal intertarsal and tarsometatarsal joints on locomotion, including the compensating effects within and between limbs. ANIMALS: 4 clinically normal horses. PROCEDURE: Gait analyses including kinematics, force plate, and inverse dynamic analysis were performed at the trot before lameness, after which synovitis was induced by injecting endotoxin into the right distal intertarsal and tarsometatarsal joints. Gait analyses were repeated 24 to 30 hours later during lameness. Differences between the stride variables during the 2 conditions (lame and sound) were identified. RESULTS: Tarsal joint range of motion, peak vertical force, and vertical impulse were decreased during lameness. Mechanical deficits included a decrease in negative work performed by the tarsal extensors during the early stance phase and a decrease in positive work by the tarsal extensors during push off. No compensatory changes in work were performed by other joints within the lame hind limb during the stance phase. Vertical impulse in the diagonal forelimb decreased, but there were no significant changes in forces or impulses in the ipsilateral forelimb or contralateral hind limb. CONCLUSION AND CLINICAL RELEVANCE: Results indicate that horses are able to manage mild, unilateral hind limb lameness by reducing the airborne phase of the stride rather than by increased loading of the compensating limbs.     

A comparison of aggressiveness and deoxynivalenol production between Canadian <Emphasis Type="Italic">Fusarium graminearum</Emphasis> isolates with 3-acetyl and 15-acetyldeoxynivalenol chemotypes in field-grown spring wheat

Twenty four isolates of Fusarium graminearum, half of which were 3-acetyldeoxynivalenol (3-ADON) and half 15-acetyldeoxynivalenol (15-ADON) chemotypes, were tested for their ability to produce deoxynivalenol and to cause Fusarium head blight (FHB) in spring wheat cultivars. The objectives of this study were to determine (1) whether 3-ADON isolates differ in aggressiveness, as measured by the FHB index, and DON production from 15-ADON isolates under field conditions, and (2) whether the performance of resistant host cultivars was stable across isolates. Field tests of all isolates were conducted with three replicates at each of two locations in Canada and Germany in 2008 with three host genotypes differing in FHB resistance level. The resistant host genotype showed resistance regardless of the chemotype or location. The differences between mean FHB indices of 3-ADON and 15-ADON isolates were not significant for any wheat genotype. In contrast, average DON production by the 3-ADON isolates (10.44 mg kg⁻¹) was significantly (P < 0.05) higher than for the 15-ADON isolates (6.95 mg kg⁻¹) at three of the four locations where moderately resistant lines were tested, and at both locations where susceptible lines were evaluated. These results indicate that 3-ADON isolates could pose a greater risk to food safety. However, as the mean aggressiveness and DON production of 3-ADON and 15-ADON chemotypes was similar on highly resistant lines, breeding and use of highly resistant lines is still the most effective measure of reducing the risks associated with DON in wheat.     

单克隆抗体检测栗疫菌dsRNA的研究初报

 本文利用dsRNA特异性单克隆抗体,采用双抗体夹芯ELISA法,检测了栗疫菌中的dsRNA.结果表明,该法不仅能从栗疫菌低毒力菌株的总核酸粗提液中检测到dsRNA而不受其它核酸的干扰,而且比电泳法简便迅速,在大量筛选含dsRNA的栗疫菌低毒力菌株中具有很大的实用价值。     

Detection of Bartonella spp. in wild rodents in Israel using HRM real-time PCR

The prevalence of Bartonella spp. in wild rodents was studied in 19 geographical locations in Israel. One hundred and twelve rodents belonging to five species (Mus musculus, Rattus rattus, Microtus socialis, Acomys cahirinus and Apodemus sylvaticus) were included in the survey. In addition, 156 ectoparasites were collected from the rodents. Spleen sample from each rodent and the ectoparasites were examined for the presence of Bartonella DNA using high resolution melt (HRM) real-time PCR. The method was designed for the simultaneous detection and differentiation of eight Bartonella spp. according to the nucleotide variation in each of two gene fragments (rpoB and gltA) and the 16S–23S intergenic spacer (ITS) locus, using the same PCR protocol which allowed the simultaneous amplification of the three different loci. Bartonella DNA was detected in spleen samples of 19 out of 79 (24%) black rats (R. rattus) and in 1 of 4 (25%) Cairo spiny mice (A. cahirinus). In addition, 15 of 34 (44%) flea pools harbored Bartonella DNA. Only rat flea (Xenopsyla cheopis) pools collected from black rats (R. rattus) were positive for Bartonella DNA. The Bartonella sp. detected in spleen samples from black rats (R. rattus) was closely related to both B. tribocorum and B. elizabethae. The species detected in the Cairo spiny mouse (A. cahirinus) spleen sample was closely related to the zoonotic pathogen, B. elizabethae. These results indicate that Bartonella species are highly prevalent in suburban rodent populations and their ectoparasites in Israel. Further investigation of the prevalence and zoonotic potential of the Bartonella species detected in the black rats and the Cairo spiny mouse is warranted.     

Hydraulic Retention Time Influence on Improving Flocculation in the Activated Sludge Processes Through Polyelectrolytes

Hydraulic retention time (HRT) influence improving sludge flocculation with adding the polyelectrolytes (non-ionic, anionic, and cationic) was studied on an activated sludge (AS) system fed with synthetic domestic wastewater (SDW), dairy industry wastewater (DIW), and caramel industry wastewater (CIW). The sludge volumetric index, food/microorganism ratio (F/M), and mixed liquor volatile suspended solids at different HRTs (6, 8 and 10 h) were monitored on an experimental model. Results showed that both SDW and IW had the best sludge flocculation conditions at 8 h and 100 mL of non-ionic polyelectrolyte (0.2 mg L^?1). In addition, this phenomenon reached the organic matter removal efficiencies of 95.9, 95.7, and 94.2% for SDW, DIW, and CIW, respectively. Therefore, optimum HRT increased the organic matter removal efficiencies by 10%, sludge concentration by 37% (22–55%), and F/M ratio by 70%. Moreover, the polyelectrolytes used in AS improved the sludge flocculation by 2.9 times.