Archives of Virology

Patterson, S.; Bingham, R.

doi: 10.1007/BF01348016pmid: 187152

Infectious bronchitis virus was observed to enter cells of chicken chorioallantoic membrane by viropexis. There was no support for the suggestion that entry took place by fusion of viral and plasma membranes. The results of electron microscopy showed that virus attachment occurred both at 4° and at 37° C. Viropexis was not observed until the preparations were warmed. Similar results were obtained using chicken kidney cells. Quantitative data obtained from a plaque counting system employing chicken kidney cells indicated that attachment was the same at both temperatures and that some virus particles were taken up at 4° C.

Snodgrass, D.; Wells, P.

doi: 10.1007/BF01348017pmid: 999520

Gnotobiotic lambs were protected against rotavirus infection by the presence in the gut at the time of infection of colostrum or serum containing antibodies to rotavirus. This protection was observed even when passively-acquired antibody was not present in the serum of the infectod lamb. Infection under these conditions may have conferred immunity to subsequent challenge.

Gil-Fernandez, Carmen; García-Gancedo, A.; Vilas-Minondo, Pilar

doi: 10.1007/BF01348018pmid: 1033755

A plaque assay method using ASFV previously adapted to growth in chick embryo fibroblasts is described. Chick embryo fibroblast monolayers under bactoagar or methylcellulose have been employed using cysteine, arginine, DEAE-Dextran and HEPES as additives. Plaque production was optimal under methylcellulose. HEPES rendered the plaques more clear when used with the overlay. Arginine enhances plaque formation with bactoagar, and DEAE-Dextran doubles the plaque size. The growth curve of ASFV in chick embryo monolayers has been studied.

Issinger, O.; Falk, H.

doi: 10.1007/BF01348019pmid: 187153

A comparison of the coat protein patterns of the wild types of the related phages T3 and T7 on SDS polyacrylamide gel electrophoresis was carried out. After infection of the nonpermissive host with T7 amber mutants in genes 7, 11, 12, 13 or 17 and T3 amber mutants in genes 11, 12, 13 and 17 respectively, noninfectious, DNA containing particles were produced. The protein pattern, as well as electron microscopy of defective particles of T3 and T7 led to the conclusion that the proteins specified by genes 11, 12, 13 and 17 are tail proteins whereas the proteins coded by genes 7, 8, 10, 14, 15 and 16 enter the head structure. The “serum blocking protein” (gene 17 product) seems to play a different role in the assembly of T3 and T7 tails, since T3 particles defective in gene 17 did not show any tail structure connected with the head whereas T7 particles defective in gene 17 had a tail which looked different from that of the wildtype.

Ogura, H.; Bauer, H.

doi: 10.1007/BF01348020pmid: 187154

A thermolabile as well as thermosensitive mutant of vesicular stomatitis virus, VSV-tl-17, could be thermostabilized by phenotypic mixing with avian RNA tumor viruses (ATV). Biological, immunological and morphological studies revealed that this effect is due to a replacement of the thermolabile projections of the VSV by the avian tumor viral projections. The arrangement of projections of VSV and ATV on phenotypically mixed viria was studied by electron microscopy.

Wardley, R.

doi: 10.1007/BF01348021pmid: 999521

The inter-epidemic phase of feline calicivirus was studied in a number of cats. During this period animals asymptomatically shed infective virus which was monitored at a number of sites and during different environmental conditions. Analysis of the amounts of virus shed by different cats showed that excretion occurred almost exclusively from the oropharynx, fluctuated with time, but was not influenced by periods of natural or artificial stress. Viral excretion from one individual cat was fairly constant although it appears that cats might be divided into high, medium or low level excretors. This variation in levels of excretion appears to have epidemiological importance in that high-level excretors more easily infect susceptible individuals.

Thomas, L.; Stott, E.; Jebbett, Jean; Hamilton, Susan

doi: 10.1007/BF01348022pmid: 11765

Respiratory syncytial (RS) virus grown in organ cultures of bovine foetal trachea at 37° C and pH 7.2 reached maximum titres of up to 1 × 105 PFU/ml between 11 and 21 days after inoculation. Virus yield was increased three fold by incubation at 33° C, but depressed by the addition of RS virus antiserum, with or without bovine complement, or by the addition of alveolar macrophages. Variation in pH or the concentration of foetal calf serum and magnesium chloride did not affect the virus yield. Virus growth did not affect ciliary activity of the cultures. Histological changes involved slight flattening of the epithelium and the appearance of phloxinophilic inclusion bodies.

Liu, I.; Zee, Y.

doi: 10.1007/BF01348023pmid: 187155

This study showed that Vesicular Stomatitis Virus (Indiana) in most instances was not capable of replicating inAedes aegypti when imbibed by the mosquitoes on a viremic host. Rapid inactivation of the virus was observed in some cases within 24 hours after imbibition. Attempts to demonstrate virus inactivation by midgut contentsin vitro were not successful.

Lion, G.; Mombaerts-Servais, Muriel; Mouton, R.

doi: 10.1007/BF01348024pmid: 999522

Viable monolayers of KB cells were maintained without passage for up to one year by adding 2 × 10−3 m caffeine to the medium, while untreated monolayers degenerated after 2 weeks. When adenoviruses type 2 and 17 were titrated on caffeine-stabilised KB cells, the late breakthrough of cytopathic effect at terminal dilutions (up to 40 days after inoculation) resulted in titre determinations up to 100-fold higher than those measured before spontaneous degeneration in untreated cells. Yields of adenovirus type 2 in caffeine-treated KB cultures infected at different multiplicities and harvested at different intervals were equal to, or up to 100-fold higher than those obtained in untreated cultures.