M. C. Quimby

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.

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.

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.

Duck viral enteritis: microtiter plate isolation and neutralization test using the duck embryo fibroblast cell line

SUMMARY The duck embryo fibroblast cell line CCL-141 was found to be visibly susceptible to the agent of duck viral enteritis. Homogenates of tissues from victims of an epizootic were used in a microtiter plate system for direct isolations and concurrent virus identifications by serum-neutralization tests. Definitive virological results were obtained within 60-72 hours. Procedures are described for using this combination of cells and assay system for efficient and economical testing that is not restricted by seasonal scarcities of ducklings or fertile duck eggs.

Towards a practical fail-safe system of managing poikilothermic vertebrate cell lines in culture.

SummaryA series of 13 integrated precepts is used in a system for managing continuous laboratory propagation of poikilothermic vertebrate cell lines. The precepts are listed in sequence of application and discussed.

Duck viral enteritis: a comparison of replication by CCL-141 and primary cultures of duck embryo fibroblasts.

Cultures of primary cells and a line of fibroblast-like cells from the Pekin duck were both compared for their replication of the herpesvirus of duck viral enteritis. The two kinds of cells were equally accurate for quantifying virus upon isolation. Also, one-step growth curves showed that in both kinds of cultures new virus appeared by the 18th hour and that infectivity peaked at about 36 hours. Primary cultures yielded about 5.6 times as much virus as did the cell line, though plaques were more easily discerned in the latter. Because of availability, uniformity, and their known health history, CCL-141 cells offer some advantages for work with the agent of duck viral enteritis.

Tadpole Edema Virus: Pathogenesis and Growth Studies and Additional Sites of Virus Infected Bullfrog Tadpoles

Considering geographic origin, method of isolation, and the life stage, health and host species, the polyhedral cytoplasmic amphibian viruses thus far cultured belong to one of three categories. The first category consists of viruses obtained directly from adult Rana pipiens—with or without renal adenocarcinoma—either from northcentral United States or from New England and adjacent Canada (1, 2, 3, 4). The second category comprises viruses from larval or adult Diemictylus viridescens (formerly, Triturus viridescens) from New England or southeastern United States—efts previously inoculated with New England R. pipiens kidney tumor cells (4, 5) and more recently virus has been isolated directly from newts (6). The third category is a group of viruses isolated directly from normal adult or normal and diseased tadpoles of Rana catesbeiana from northcentral or southeastern United States (7).