Ken Wolf

Established Eurythermic Line of Fish Cells in vitro

An established line of fish cells has been propagated in vitro for 21 months and 48 subcultivations. Important characteristics of the cells are described.

Biology Contravenes Taxonomy in the Myxozoa: New Discoveries Show Alternation of Invertebrate and Vertebrate Hosts

For 80 years the infectivity of salmonid whirling disease has eluded discovery. New findings now show that this myxosporean disease of fish is initiated by what is regarded as an actinosporean produced in a tubificid oligochaete. Experimental results provide evidence that, instead of being considered as representatives of separate classes in the phylum Myxozoa, the myxosporean and actinosporean are alternating life forms of a single organism.

Lymphocystis Virus: Isolation and Propagation in Centrarchid Fish Cell Lines

A virus from fish with lymphocystis disease was isolated in fish cell cultures. Eleven serial transfers were made and the pathognomonic lymphocystis cells were produced in vitro in each transfer. Fish inoculated with 6th- and 9th-passage material developed the disease, and virus was reisolated front them.

Poikilotherm vertebrate cell lines and viruses: a current listing for fishes.

SummaryA survey of the literature and of work being done in vertebrate cell culture shows that there are currently in existence and available to investigators some 61 cell lines representing 17 families and 36 species of fish. The literature of fish virology shows that at least 17 fish viruses have been isolated and that at least 15 others have been visualized by electron microscopy. A minimum of four major virus groups—rhabdovirus, orthomyxovirus, iridovirus and herpesvirus—are known from fish. Original references, key reviews and sources of cell lines are given.

AMPHIBIAN CELL CULTURE: PERMANENT CELL LINE FROM THE BULLFROG (RANA CATESBEIANA).

A line of fibroblast cells has been established from tongue tissue of the bullfrog (Rana catesbeiana). The cells are near-triploid and were subcultured 57 times during the 22/3 years of their existence. Some of their characteristics are described.

Preparation of Monolayer Cell Cultures from Tissues of Some Lower Vertebrates

Cold trypsin dispersion at pH 7.2 was used to obtain cultivable cells and cell groups from tissues of six species of fresh-water bony fishes, a frog, and a turtle. The cells readily attached to glass and were capable of at least limfted, and in some cases extended, division in media consisting of commercially available components.

Egg-associated transmission of IPN virus of trouts

Abstract Infectious pancreatic necrosis virus (IPN) of salmonid fishes has been isolated and identified in suspect but normal-appearing stocks of adult brook trout (Salvelinus fontinalis), and thus a pattern for the epizootiology of the virus has been demonstrated. Virus titers as high as 106.5 ID50 were found in egg fluids from 7 of 12 fish tested. In contrast, egg homogenates contained much less virus; their maximum titer was 101.8 ID50. The presence of virus within the eggs, however, was not established. Viral neutralizing ability of serum from the same fish showed an inverse relationship to the presence of virus in “ovarian fluid.” The highest serum titers occurred in those fish from which little or no virus had been isolated.

Test of 34 Therapeutic Agents for Control of Kidney Disease in Trout

Abstract Sixteen strains of fish kidney disease bacterium were tested in vitro to determine their reaction to 34 therapeutic agents. On the basis of the results obtained ten of the drugs were employed in experimental therapy of kidney disease in eastern brook trout (Salvelinus fontinalis). Erythromycin at the rate of 100 milligrams per kilogram of fish per day (4.5 grams per 100 pounds of fish) for 21 days gave the best results. Other drugs gave only temporary benefit if any.

Salmonid viruses: infectious pancreatic necrosis virus

Epizootics occurred among young trout in France, and the behavior and symptoms suggested infectious pancreatic necrosis (IPN) virus. Specimens preserved in glycerol were sent to the U.S.A. for virological examination. Virus was isolated from four of five lots, but neutralization with antiserum against ATCC VR299 strain IPN virus was incomplete. Electron microscopy, bioassay, histopathology, and serology were used to identify the viruses. The results showed the agents to be new strains of IPN virus with distinctive antigenicity and heretofore unknown lability at 4°C and marked vulnerability to a single freezing and thawing. A method of improving stability in storage was found. Electronmicrographs, tabular and graphic data are presented.

Experimental propagation of lymphocystis disease of fishes

Abstract The agent of lymphocystis disease has been propagated under laboratory conditions for more than 2 years. Although several hatchery-propagated centrarchids are susceptible, the bluegill (Lepomis macrochirus) is the host of choice because it is most easily maintained. At 12.5° the disease was transmitted by implantation and by injection, but there was no evidence of fish-to-fish spread, nor seasonal change in host susceptibility. The infective agent was clearly demonstrated to be filterable (Millipore HA). It retained infectivity in storage at −20° for almost two years, and its viability after desiccation was confirmed. These facts support its postulated viral nature. The virus was glycerol- and ether-sensitive and did not induce formation of giant lymphocystis cells in monolayer cultures of bluegill ovary cells.