In vitro study (Rusitec) of the action of abierixin, a new ionophore antibiotic, on the end products of fermentation and the degradation of nitrogen in the rumen

We investigated the capacity of a new ionophore antibiotic, abierixin, to modify fermentations in the rumen using a semi-continuous fermenter (Rusitec). As in the studies carried out on a "batch" fermenter (HILLAIRE et al., 1989a), abierixin failed to alter volatile fatty acids and gas productions but, in contrast, it limited the degradation of dietary nitrogen without affecting microbial synthesis. This molecule which has a low level of toxicity and is capable of improving the use of dietary proteins by ruminants, was found to be more effective when used at very low dose levels.     

Isolation and characterization of Streptococcus sp. from diseased flounder (Paralichthys olivaceus) in Jeju Island

Streptococcus sp. is gram-positive coccus that causes streptococcal infections in fish due to intensification of aquaculture and caused significant economic losses in fish farm industry. A streptococcal infection occurred from cultured diseased olive flounder (Paralichthys olivaceus) in May, 2005 at a fish farm in Jeju Island, Korea. The diseased flounder exhibited bilateral exophthalmic eyes and rotten gills; water temperature was 16~18℃ when samples were collected. Of the 22 fish samples collected, 3 samples were identified as Lactococcus garvieae and 18 samples were identified as Streptococcus parauberis by culture-based, biochemical test. Serological methods such as slide agglutination, hemolysis and antimicrobial susceptibility test were also used as well as multiplex PCR-based method to simultaneously detect and confirm the pathogens involved in the infection. S. parauberis and L. garvieae have a target region of 700 and 1100 bp., respectively. One fish sample was not identified because of the difference in the different biochemical and serological tests and was negative in PCR assay. In the present study, it showed that S. parauberis was the dominant species that caused streptococcosis in the cultured diseased flounder.     

Metabolism of phenyl-3 H-indoles by cell suspension of Acer pseudoplatanus L. and their phytotoxicity

Phenyl-3H-indoles inhibited growth of Acer pseudoplatanus cells but were not toxic in vivo. Experiments were conducted to find out why the compounds gave a toxic response in cell suspension but not a phytotoxic response in whole plants. The behaviour of two phenyl-3H-indoles, (2-(4-chlorophenyl)-3,3-dimethyl-5-fluoro-3H-indole and 2-(4-chlorophenyl)-3,3-dimethyl-5-carboxy-3H-indole), was investigated in cell suspensions. Absorption and metabolism by cells were rapid. The major metabolite was identified as a polar conjugate of 2-(3-hydroxy-4-chlorophenyl)-3,3-dimethyl-5-fluoro-3H-indole. This metabolite did not inhibit cell growth. Different phenyl 3H-indole analogues with the hydroxylation site blocked were synthesised to determine if metabolism was involved in the disappearance of activity in vivo. The results indicated that this was not the case and thus the absence of phytotoxicity must be related to another factor.     

Alginate Hydrogels Coated with Chitosan for Wound Dressing

In this work, a coating of chitosan onto alginate hydrogels was realized using the water-soluble hydrochloride form of chitosan (CH-Cl), with the dual purpose of imparting antibacterial activity and delaying the release of hydrophilic molecules from the alginate matrix. Alginate hydrogels with different calcium contents were prepared by the internal setting method and coated by immersion in a CH-Cl solution. Structural analysis by cryo-scanning electron microscopy was carried out to highlight morphological alterations due to the coating layer. Tests in vitro with human mesenchymal stromal cells (MSC) were assessed to check the absence of toxicity of CH-Cl. Swelling, stability in physiological solution and release characteristics using rhodamine B as the hydrophilic model drug were compared to those of relative uncoated hydrogels. Finally, antibacterial activity against Escherichia coli was tested. Results show that alginate hydrogels coated with chitosan hydrochloride described here can be proposed as a novel medicated dressing by associating intrinsic antimicrobial activity with improved sustained release characteristics.     

Plasmid profiling of Flavobacterium psychrophilum isolates from ayu (Plecoglossus altivelis altivelis) and other fish species in Japan

In order to evaluate the genetic variability of the causative agent of cold water disease (CWD), plasmid profiling was used to characterize Flavobacterium (F.) psychrophilum isolates (n = 169). Size analysis of plasmids in F. psychrophilum isolates (n = 128) from several fish species demonstrated that six kinds of plasmids were harbored, and ayu isolates had different profiles compared to other isolates. Moreover, multiple isolates (n = 41) from CWD outbreaks in 2002 to 2003 at a single ayu farm were examined to determine differences between isolates from successive outbreaks and showed different profiles by the sources of seedlings.     

Analytical validation of a point-of-care test and an automated immunoturbidimetric assay for the measurement of canine C-reactive protein in serum

C-reactive protein (CRP) is an acute phase protein, which is used to evaluate and monitor the response of the innate immune system to a variety of inflammatory processes in the dog. The purpose of this study was to analytically validate a point-of-care assay (IDEXX Catalyst CRP Test) and an immunoturbidimetric assay (Gentian Canine CRP Immunoassay) for the measurement of serum CRP concentrations in dogs. These 2 assays (Catalyst, Gentian) were compared to a previously validated enzyme-linked immunosorbent assay (Tridelta Development EIA Canine CRP Assay). Linearity, precision, reproducibility, and accuracy were assessed using leftover serum samples. Agreement between assays was assessed using leftover serum samples and serum from clinically healthy dogs. Observed to expected ratios (O/E) for dilutional parallelism were 83.9 to 163.1% and 108.3 to 160.6% for the Catalyst and the Gentian assays, respectively. Coefficients of variation for intra-assay variability ranged from 6.4 to 9.5% for the Catalyst assay and 1.5 to 2.6% for the Gentian assay. Coefficients of variation for inter-assay variability ranged from 3.8 to 18.2% for the Catalyst assay and 4.5 to 5.8% for the Gentian assay. The mean O/E for recovery were 97.9% and 98.5% for the Catalyst and Gentian assays, respectively. Correlations between assays were as follows: Catalyst and Tridelta (R² = 0.76), Gentian and Tridelta (R² = 0.79), and Catalyst and Gentian (R² = 0.98). The Catalyst and Gentian assays are both acceptable for measuring CRP in dog serum, but their results are not directly comparable with the Tridelta assay.     

Detection of Mycobacterium paratuberculosis antigen with colloidal immunogold in naturally infected sheep.

The anti-Mycobacterium paratuberculosis polyclonal serum is proved useful for labelling Mycobacterium paratuberculosis in glutaraldehyde-osmium-fixed and epon-embedded intestinal samples from sheep with clinical symptoms of paratuberculosis. M. paratuberculosis marked with antibody-coated colloidal gold stain was seen in macrophages, epithelioid cells, giant cells and neutrophils throughout intestinal mucosa. In large macrophages with a low lysosomal content, a great number of intact mycobacteria was seen within phagosomes. In macrophages with average lysosomal content, very few intact mycobacteria or mycobacterial debris were present and lysosome-phagosome fusions were observed. Mycobacteria within neutrophils were scanty. These results show the usefulness of colloidal immunogold techniques for studies of the pathogenesis of paratuberculosis.     

Selection criteria for suites of landscape species as a basis for site-based conservation

Focal-species approaches provide tractable frameworks for structuring site-based conservation, but explanations of how and why focal species are chosen are often lacking. This paper outlines the rationale and selection criteria for one such strategy: the “Landscape Species Approach.” We define five criteria for selecting landscape species (area requirements, heterogeneity, ecological function, vulnerability, and socioeconomic significance) and illustrate the process using data from two landscapes, the northwestern Bolivian Andes and northern Congo. Candidate species from each site were scored and suites of complementary landscape species were assembled. Like all focal-species approaches (and indeed all conservation planning), this approach is not without biases. However, by making our assumptions explicit and allowing evaluation of the inherent biases, we attempt to provide a transparent, replicable method for identifying species around which to structure site-based conservation (landscape species). The process is also useful for identifying data gaps, ranking threats, and setting research priorities. Clear justification and selection criteria should accompany any focal species strategy to allow methods to be replicated, tested, and refined.     

Effect of anaesthesia of the palmar digital nerves on proximal interphalangeal joint pain in the horse

REASONS FOR PERFORMING STUDY: Anaesthesia of the palmar digital nerves is claimed to attenuate lameness in some horses that are lame because of pain in the proximal interphalangeal (PIP) joint. OBJECTIVE: To determine the response of horses with pain in the PIP joint to anaesthesia of the palmar digital nerves. METHODS: Horses were video recorded trotting before and after induction of pain in the PIP joint and 10 mins after anaesthesia of the palmar digital nerves. The palmar digital nerves were anaesthetised 3 times at different sites, and the video recorded gaits were scored subjectively. RESULTS: The median lameness score of gaits after administration of 2% mepivacaine 1 cm proximal to the cartilages of the foot was not significantly different from the median lameness score before anaesthesia of the palmar digital nerves (P > or = 0.05), although that of 1 of 6 horses improved markedly. The median lameness score was significantly (P < or = 0.05) improved after mepivacaine was administered 2 and 3 cm proximal to the cartilages of the foot. CONCLUSIONS: The PIP joint is unlikely to be anaesthetised when the palmar digital nerves are anaesthetised at the proximal margin of the cartilages of the foot. POTENTIAL RELEVANCE: Pain within the PIP joint cannot be excluded as a cause of lameness when lameness is attenuated by anaesthesia of the palmar digital nerves at any site proximal to the proximal margin of the cartilages of the foot.     

Evaluation of ELISA and Western Blot Analysis using three antigens to detect anti-Trichinella IgG in horses

We assessed a serological method for detecting Trichinella infection in horses, specifically, an ELISA using three antigens to detect anti-Trichinella IgG (i.e. a synthetic tyvelose glycan-BSA (stg-BSA) antigen, an excretory/secretory (ES) antigen, and a crude worm extract (CWE) antigen). Serum samples were collected from 2502 horses (433 live horses from Romania and 2069 horses slaughtered in Italy and originating from Italy, Poland, Romania, and Serbia). Serum samples were also taken from horses experimentally infected with different doses of T. spiralis and T. murrelli larvae, as controls. The cut-off value of ELISA was determined on serum samples from 330 horses from Trichinella-free regions of Italy, which were also examined by artificial digestion of preferential-muscle samples. In the experimentally infected horses, the stg-BSA and ES antigens were less sensitive than the CWE antigen. Trichinella spiralis showed a higher immunogenicity than T. murrelli, and the IgG immunoresponse was dose-dependent. The kinetics of anti-Trichinella IgG were similar among all experimentally infected horses. No circulating antibodies were detected 4-5 months after experimental infection, although these horses still harbored infective larvae. Depending on the antigen used, for 4-7 of the 330 horses from Trichinella-free areas, the optical density (OD) of the serum sample was higher than the cut-off value, yet these samples were negative when subjected to Western Blot. Similar results were obtained for the 1739 horses slaughtered in Italy (originating from Italy, Poland, Romania, and Serbia) and the 433 live Romanian horses. Of the 4 horses with muscle larvae, only one was positive by ELISA and Western Blot. Because the anti-Trichinella IgG remain circulating for only a short period of time, whereas the larvae remain infective for longer periods, serology cannot be used for either diagnosing Trichinella infection in horses or estimating the prevalence of infection. Artificial digestion of at least 5 g of preferential-muscle tissue continues to be the method of choice at the slaughterhouse for preventing equine-borne trichinellosis in humans.