In two separate experiments we investigated the effects of different types of suture material and patterns on wound healing in rainbow trout Oncorhynchus mykiss with and without transmitter implants. We used absorbable and nonabsorbable monofilament and braided silk sutures in simple interrupted and vertical mattress patterns to close 3-cm incisions on rainbow trout. Braided silk sutures and vertical mattress suture patterns caused significantly more tissue inflammation (P Ͻ 0.05) as shown by macroscopic analysis. However, there were no significant differences in the histology or strength of the wounds related to the type of suture material or the type of suture pattern used. Dummy radio transmitters compounded the inflammatory effect silk had on healing incisions compared with inflammation without transmitters.

Infections of branchial epithelium by intracellular gram-negative bacteria, termed epitheliocystis, have limited culture of Arctic charr Salvelinus alpinus. To characterize a bacterium associated with epitheliocystis in cultured charr, gills were sampled for histopathologic examination, conventional and immunoelectron microscopy, in situ hybridization, 16S ribosomal DNA (rDNA) amplification, sequence analysis and phylogenetic inference. Sampling was conducted at the Freshwater Institute (Shepherdstown, West Virginia, USA) during outbreaks of epitheliocystis in April and May 2002. Granular, basophilic, cytoplasmic inclusions in charr gill were shown to stain with Macchiavello, Lendrum's phloxine-tartrazine and Gimenez histochemical techniques. Ultrastructurally, inclusions were membrane-bound and contained round to elongate reticulate bodies that were immunoreactive to an antibody against chlamydial lipopolysaccharide, suggesting the presence of similar epitopes. DNA extracted from gills supported amplification of the most polymorphic and phylogenetically relevant region of the 16S rRNA gene, which had 97 to 100% identity with several uncultured clinical Neochlamydia spp. (order Chlamydiales) Clones WB13 (AY225593.1) and WB258 (AY225594.1). Sequence-specific riboprobes localized to inclusions during in situ hybridization experiments. Taxonomic affiliation was inferred by distance-and parsimony-based phylogenetic analyses of the 16S sequence, which branched with Neochlamydia hartmannellae in the order Chlamydiales with high confidence. This is the first molecular characterization of a chlamydia associated with epitheliocystis in Arctic charr and the fourth Neochlamydia spp. sequence to be associated with epitheliocystis. Presence of a clinical neochlamydial sequence, first identified from a cat, in Arctic charr suggests a possible mammalian and piscine host range for some environmental chlamydiae.KEY WORDS: Arctic charr · Environmental chlamydiae · Epitheliocystis · In situ hybridization · Neochlamydia · Salvelinus · Ultrastructure · 16S ribosomal RNA gene Resale or republication not permitted without written consent of the publisherDis Aquat Org 76: [27][28][29][30][31][32][33][34][35][36][37][38] 2007 ized ultrastructurally (Hoffman et al. 1969, Wolke et al. 1970, Nylund et al. 1998), antigenically (Groff et al. 1996 or, most recently, molecularly (Draghi et al. 2004, Meijer et al. 2006 as chlamydia or chlamydia-like bacteria. Horn & Wagner (2001) have proposed the term 'environmental chlamydia' to encompass these diverse, and sometimes medically relevant, chlamydiae isolated from environmental sources, while others suggest a more general term, 'novel chlamydia', to include those chlamydiae not members of the Chlamydiaceae (Corsaro & Greub 2006). In epitheliocystis, infection of branchial epithelium results in formation of intracytoplasmic basophilic granular inclusions that distend the cytoplasm of individual epithelial cells. Host responses to infection vary from non-proliferative, i.e. with litt...

A crude extracellular preparation (CEP) from a strain of Flavobacteriumpsychrophilum recovered from a case of necrotic myositis affecting rainbow trout was capable of causing severe muscle necrosis in rainbow trout following intramuscular injection. Cell wall‐associated preparations, however, were unable to produce similar lesions in experimentally injected fish. The CEP degraded gelatin and type II collagen but not type I or type IV collagen. Furthermore, the CEP did not degrade 2‐furanacryloyl‐ l‐leucylglycyl‐ l‐prolyl‐alanine (FALGPA), chondroitin sulphates A, B or C, heparan sulphate, keratan sulphate, hyaluronic acid, elastin or rainbow trout erythrocytes. The addition of the protease inhibitors 1,10‐phenanthroline, ethylenediamine‐tetraacetic acid (EDTA) and EGTA to the CEP halted its ability to degrade gelatin in vitro and to produce muscle necrosis in rainbow trout in vivo. In vitro and in vivo activity was restored following the addition of 1 m m zinc chloride to the protease inhibitor‐treated CEP, suggesting that this strain of F. psychrophilum secretes a protein complex with zinc metalloprotease‐like activity. This protein complex, therefore, appears to be involved in the pathogenesis of necrotic myositis in rainbow trout.

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Bacterial gill disease was horizontally transmitted both within and between salmonid species by using good-quality water common to both sick and healthy fish, and by using young and mature animals. Clinical disease was produced within 24 h, and mortality resulted often within 48 h, even in 2-or 3-year-old rainbow trout Oncorhynchus mykiss. Clinical disease was correlated with the appearance of filamentous bacteria on the gill surface. These bacteria were isolated and determined to be morphologically, biochemically, and antigenically related to Flavobacterium branchiophila. Subsequently, they were used to produce bacterial gill disease in fingerling rainbow trout by adding a pure culture of 10 5 organisms/mL of tank water, once again, good water quality conditions were maintained. Attachment of large numbers of bacteria to the gill surface was seen immediately postexposure, followed by clinical disease within 20 h and death by 24 h.

A novel, simple, rapid, sensitive and reproducible microassay is described for determination of myoglobin and hemoglobin content of myocardial and skeletal muscle biopsy specimens from various mammals, birds and fish. As little as 50 mg of tissue is needed and myoglobin concentrations lower than 1 mg% can be detected. Myoglobin and hemoglobin are separated at alkaline pH by ammonium sulfate extraction followed by ultrafiltration. Heme content is determined by absorption of the Soret band when the hemoprotein extract is visibly colored or more sensitively by its peroxidase activity when the extract has low color. The heme reacts with tertiary-butyl hydroperoxide and orthotolidine to generate a blue color. Hemoglobin content is correlated with myoglobin content and is related to aerobic capacity and blood flow to the tissue. Myoglobin content varied over 5 orders of magnitude up to 7 per cent of the weight of tissue, whereas hemoglobin content varied over 2 orders of magnitude up to 6 per cent of tissue weight. Myoglobin content is increased in species with high basal metabolic rate, high physical activity, prolonged diving capacity, fatigue resistance, and red muscle, whereas it is decreased in white muscle, iron-deficient animals, animals with sedentary lifestyles, and in animals and tissues with small fiber diameters such as avian or fish hearts.

Eleven classic benign "fibroepithelial polyps" of the vagina were examined using a panel of immunocytochemical agents. Two were also examined electron microscopically. In all cases the stellate and multinucleate stromal cells characteristic of these lesions stained strongly for desmin, indicating muscle intermediate filament production. In common with uterine fibroleiomyomata, numerous mast cells were also often seen. Myoglobin staining was negative. Electron microscopical examination confirmed that the stromal cells contained abundant thin filaments with focal densities and also showed the ultrastructural features usually associated with myofibroblasts.It is concluded that these tumours would be better designated polypoid myofibroblastomas in view of the above findings.