Comparative Susceptibility of Channel Catfish,Ictalurus punctatus; Blue Catfish,Ictalurus furcatus; and Channel (♀) × Blue (♂) Hybrid Catfish to Edwardsiella piscicida,Edwardsiella tarda,and Edwardsiella anguillarum

Members of the genus Edwardsiella are important pathogens of cultured and wild fish globally. Recent investigations into the phenotypic and genotypic variation of Edwardsiella tarda have led to the segregation of E. tarda into three distinct taxa: E. tarda, Edwardsiella piscicida, and Edwardsiella anguillarum. In catfish aquaculture in the southeastern USA, E. piscicida has been more commonly associated with disease than E. tarda or E. anguillarum, and recent research has demonstrated E. piscicida to be more pathogenic in channel catfish than E. tarda or E. anguillarum. Anecdotal reports from industry suggest an increased prevalence of E. piscicida associated with the culture of channel (♀) × blue (♂) hybrid catfish. This work investigated the comparative susceptibility of channel catfish, blue catfish, and their hybrid cross to molecularly confirmed isolates of E. tarda, E. piscicida, and E. anguillarum. There was significantly higher mortality in hybrid catfish compared to channel catfish following intracoelomic injection of E. piscicida. To our knowledge, E. piscicida is the first bacterial pathogen to demonstrate increased pathogenicity in hybrid catfish compared to channel catfish.     

Factors associated with and prevalence of high Malassezia pachydermatis numbers on dog skin.

The prevalence of cutaneous Malassezia spp was evaluated in a semiquantitative fashion at 3 sites on 98 dogs examined because of various dermatoses. Thirty (10.2%) of the sites and 19 (19.4%) of the dogs had Malassezia spp amounts higher than that found on grossly normal skin. The prevalence of higher than normal amounts did not correlate significantly with sample site, sex, or age. The factors associated with an increased prevalence of increased Malassezia spp counts were seborrheic dermatitis, recent antibiotic treatment, and breed.     

Energy and nitrogen retention and loss in broiler chickens genetically selected for leanness and fatness

1. A breeding programme based on the assessment of the body fat content of broilers by measurement of plasma very low density lipoprotein concentration has resulted in 2 lines with significantly different body fat contents. 2. Energy and nitrogen intake and retention were measured in 63- to 70-d-old females from each line during 5-d periods of indirect chamber calorimetry. Results obtained by this technique were compared with results from a previously published growth trial incorporating carcase analysis at 49 d. 3. Body weight, metabolisable energy intake, heat production, energy retention and efficiency of energy retention did not differ significantly between the fat and lean lines. 4. The proportion of energy retained as crude protein and the efficiency of crude protein retention were significantly greater in the lean line. 5. In terms of whole-body energy and nitrogen exchanges, the essential difference between the lines was therefore in the partition of the same quantity of retained energy between fat and protein deposition. 6. The results were consistent with a higher rate of breakdown of amino acids in the fat line; because heat production did not also increase, a greater proportion of retained energy therefore became available for storage as fat.     

Eructation of gas through the gastroesophageal sphincter before and after limiting distension of the gastric cardia or infusion of a beta-adrenergic amine in dogs

Gas eructation function of the gastroesophageal sphincter (GES) was investigated in 6 conscious dogs before and after a sleeve was placed around the GES and gastric cardia and during IV infusion of a beta-adrenergic amine (epinephrine). To induce eructation, nitrogen gas was insufflated (351.4 +/- 2 ml/min; mean +/- SEM) into the stomach through 1 channel of a 4-lumen catheter. After baseline studies and epinephrine infusion studies were completed in each dog, surgery was done to limit partially gastric distension by intraluminal contents by placing a silicone rubber sleeve around the GES and the first few centimeters of the cardia. Gastroesophageal sphincter pressure was 31.8 +/- 2.2 mm of Hg in baseline studies, 17.3 +/- 1.3 mm of Hg during epinephrine infusion (P. less than 0.003), and 30.3 +/- 2.2 mm of Hg after the sleeve was placed around the GES and cardia. During insufflation, gastric pressures before eructation increased to 5.74 +/- 0.41 mm of Hg before and to 15.15 +/- 1.63 mm of Hg after cardia sleeve placement (P less than 0.001). Eructation occurred at intervals of 1.83 +/- 0.41 minutes before cardia sleeve placement, and eructations were not observed with the sleeve in place. Before the sleeve was placed, administration of epinephrine resulted in an eructation interval of 0.84 +/- 0.09 minutes, which was significantly different from that in the same dogs given no drugs (P less than 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)     

Generation and characterisation of murine monoclonal antibodies specific for cervine immunoglobulin light chain, IgM and IgG.

Monoclonal antibodies (mAb) which react with cervine immunoglobulin (Ig) light chain, IgM and IgG were produced using conventional cell fusion technology. Hybridoma supernatants were initially screened for specificity against cervine Ig using an enzyme-linked immunosorbent assay (ELISA). The specificity of supernatants against size-fractionated cervine Ig was further determined. Supernatants were characterised using western blotting and autoradiographic techniques. The mAb OU1G, OU2G and OU3G were specific for cervine gamma-chain of IgG, whereas OU1L was specific for light chain of Ig. A further mAb (OU1M) bound IgM and not IgG. These mAb were found to have varying cross-reactivity against Ig from other species.     

Eosinophilic enteritis in a specific-pathogen-free cat

Moderate to severe, chronic, segmental eosinophilic enteritis was diagnosed histopathologically in a 2-year-old, specific-pathogen-free cat. Peripheral eosinophilia was not observed, although eosinophilic infiltrates were found in mesenteric lymph nodes. Typical gastrointestinal signs characteristic of this disease (diarrhea, vomiting, and anorexia) were not seen; only weight loss was observed. Treatment was not instituted. Previously reported cases of feline eosinophilic enteritis have been associated with several domestic breeds having a diversity of backgrounds. The cat of this report had a known genealogy and disease-free history, was reared under barrier conditions, and was fed a restricted diet. The cause of the disease in this cat was not determined.