Effect of hyperimmune plasma on the severity of pneumonia caused by Rhodococcus equi in experimentally infected foals

This study evaluated the prophylactic effectiveness of hyperimmune plasma (HIP) as an aid in the prevention of pneumonia caused by experimental infection with Rhodococcus equi. Thirty neonatal foals were administered R. equi HIP or saline at 2 days of age and were infected with virulent R. equi at 7 days. All foals developed signs or symptoms of respiratory disease. Radiographic scores on day 28 and neutrophil concentrations on day 49 were significantly greater in control foals, and time to respiratory effort score of 2 or higher was significantly shorter for control foals. Three foals, all in the principal group, died or were euthanized before the end of the study, but there was no significant difference in mortality between groups. VapA titers were significantly greater in principal foals. Administration of R. equi HIP decreased the severity of radiographic lesions and prolonged time to increased respiratory effort due to R. equi-induced pneumonia.     

SINGLE‐SHOT TURBO SPIN ECHO PULSE SEQUENCE FINDINGS IN DOGS WITH AND WITHOUT PROGRESSIVE MYELOMALACIA

Progressive myelomalacia is an uncommon type of ischemic, hemorrhagic spinal cord infarction. Diagnosis can be difficult, but prompt recognition is important. We hypothesized that cerebrospinal fluid signal attenuation on magnetic resonance (MR) images would be more extensive in dogs that developed progressive myelomalacia vs. control dogs. A retrospective analytic cohort study was designed. Dogs were included if they presented for acute paraplegia and loss of deep pain perception and had undergone MR imaging using both sagittal single‐shot turbo spin echo (SSTSE) and standard sagittal T2‐weighted fast spin echo (T2W) pulse sequences. Dogs were divided into progressive myelomalacia and control groups for comparisons. All MR examinations were evaluated by three reviewers blinded to patient outcome. Length of cerebrospinal fluid attenuation was recorded as a ratio to the length of the L2 vertebral body in SSTSE and T2W sequences (CSF:L2_SSTSE and CSF:L2_T2, respectively). Length of intramedullary spinal cord hyperintensity was recorded as a ratio to the length of the L2 vertebral body in T2W sequences. A total of 21 dogs were included (five in the progressive myelomalacia group and 16 in the control group). The mean CSF:L2_SSTSE attenuation value was significantly higher in dogs that developed progressive myelomalacia (CSF:L2_SSTSE = 10.7) compared to controls (CSF:L2_SSTSE = 5.4; P = 0.015). A cut off ratio of attenuation >7.4 provided optimal differentiation between groups in this study. Findings supported the conclusion that dogs with CSF:L2_SSTSE ≤ 7.4 are unlikely to develop progressive myelomalacia while dogs with CSF:L2_SSTSE > 7.4 are indeterminate for progressive myelomalacia.     

Use of a Fluorophore to Tag Arthropods for Mark-Release-Recapture Type Research

We examined the feasibility of externally marking insects with the liquid fluorescent forensic theft deterrent, SmartWater (SmartWater CSI, LLC.). We sprayed captive Lygus hesperus (Knight) (Hemiptera: Miridae), Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), and Hippodamia convergens Guérin-Méneville (Coleoptera: Coccinellidae) with SmartWater fluorophore, and then qualitatively examined them for fluorescence by visual inspection under ultraviolet (UV) light and quantitatively measured them with a multiwavelength microplate fluorometer. The results indicate that this product has enormous potential as a taggant for L. hesperus and B. tabaci. However, the marking efficiency for H. convergens was only adequate. The advantages and limitations of using SmartWater as a biological marker for arthropod mark-release-recapture research are discussed.     

Vertebrate mucus stimulates biofilm development and upregulates iron acquisition genes in Flavobacterium columnare

Columnaris disease is responsible for substantial losses throughout the production of many freshwater fish species. One of the ways in which the bacterium Flavobacterium columnare is so effective in initiating disease is through the formation of biofilms on fish skin and gills. To further explore the interaction between host factors and bacterial cells, we assayed the ability of vertebrate mucus to enhance F. columnare biofilm development. Different concentrations of catfish, tilapia and pig mucus (5–60 µg/ml) increased biofilm growth at varying degrees among F. columnare isolates. Our data suggest that vertebrate mucus acts as a signalling molecule for the development of F. columnare biofilms; however, there are clear disparities in how individual isolates respond to different mucus fractions to stimulate biofilms. The expression of iron acquisition genes among two genomovar II isolates showed that ferroxidase, TonB receptor and the siderophore synthetase gene were all significantly upregulated among F. columnare biofilms. Interestingly, the siderophore acetyltransferase gene was only shown to be significantly upregulated in one of the genomovar II isolates. This work provides insight into our understanding of the interaction between F. columnare and vertebrate mucus, which likely contributes to the growth of planktonic cells and the transition into biofilms.     

Modeling of multiple stocks and programs for master planning and feasibility studies

Public hatchery facilities increasingly respond to recreational fishing demands for larger catchable salmonids and to production programs that require a variety of species. The result of this tendency is to require more complexity in hatchery design and operations involving the simultaneous rearing of several species that results in overlapping production schedules for crops of fish that carryover from 1 year to the next. This paper presents a highly accessible spreadsheet based computer simulation model for use by culturists, designers, and program planners in designing hatchery facilities with these expanded program demands. It addresses trade offs between budget constraints, stocking objectives, available water resources, and production technologies. The model is structured so that all the assumptions for any facility program simulation can be entered on a single spreadsheet. The essential fish growth, density, flow, and feeding relationships used within the model are those based on widely used paradigms developed by Piper et al. (1982) and others. The program information assumptions include all of the essential information to simulate production runs for each group of fish within the facility, each with specific characteristics such as growth rate, feed conversion, calendar day stocking and harvest dates, and duration of the crop. Those program assumptions are linked to a series of other spreadsheets within the spreadsheet workbook that calculate weekly model simulation results for rearing space, first-pass and rearing flows, feed consumption, and phosphorus discharge for each group of fish and then for the combined results of the entire facility. The facility simulation results are automatically plotted in a graphic format for comparative evaluation of any series of production program assumptions that the operators consider in the design process. The graphic results for simulated rearing space, flow, and feeding are presented in an annual format in weekly increments. The graphic results readily present the utilization of facility space and water resources and clearly indicate opportunities to improve facility efficiency in a new simulation providing a rapid means of iterating design changes until the exercise generates the most favorable facility. Several case studies provide examples of this process for the user.     

Atomic Force Microscopy (AFM) Study of Interactions of HMW Subunits of Wheat Glutenin

Atomic force microscopy (AFM) has been used to study the noncovalent interactions of alkylated HMW subunit 1Dx5 and a M _r 58,000 peptide derived from the central repetitive domain. Both protein and peptide align side‐by‐side to form fibrils, the HMW subunit forming a branched network, and the peptide forming linear rods. The N‐ and C‐terminal domains of the subunit would, therefore, appear to contain regions that interact through noncovalent interactions in the absence of disulfide bond formation. These regions may be of importance in facilitating disulfide bond formation during protein body development.