Vesicular Exanthema Research Articles

San Miguel sea lion virus isolation, preliminary characterization and relationship to vesicular exanthema of swine virus.

BETWEEN 1932 and 1954 there were repeated outbreaks of vesicular exanthema of swine (VES) in Californian swine herds, but since 1956 no cases have occurred in the United States and this has been attributed to a federal law which prohibited the feeding of raw garbage to swine1. The continuing importance of vesicular diseases of swine, however, is suggested by reports from Italy2, Hong Kong3, Austria, Poland and Britain (personal communication from A. H. Dariri, Plum Island Animal Disease Laboratory, 1973) of a vesicular syndrome in swine that could not be ascribed to foot and mouth disease virus (FMDV).

THE UTILIZATION OF ZWITTERIONIC BUFFER SYSTEM IN THE PLAQUE ASSAY OF A FELINE CALICIVIRUS

In 1971 feline picornaviruses were placed with vesicular exanthema virus in the genus Calicivirus within the family Picornaviridae (Wildy, 1971). Several publications utilizing the tube culture technique for infectivity titrations of feline caliciviruses have appeared (Burki, 1965; Burki and Pichler, 1971). Kahn and Gillespie (1970) mentioned plaque formation by strains of feline caliciviruses but no plaque assay technique has previously been described. Although Good, Winget, Winter, Connolly, Izawa and Singh (1966) first reported the development and the possible application of certain zwitterionic amino acids as buffering systems for biological research, most virus plaque assay techniques still utilize either closed or open systems with carbon dioxide supplementation. However, Richter (1967) reported the use of a zwitterionic buffer N‐tris (hydroxymethyl) methyl‐2‐aminoethane sulphonic acid (TES) in an open system which gave results comparable to bicarbonate‐carbon dioxide buffering in air. This communication reports on the use of a zwitterionic amino acid buffer system in the development of a plaque technique for feline caliciviruses.

Buoyant density of picornaviruses in caesium salts.

SUMMARY Factors affecting the determination of buoyant density in caesium salts of several animal picornaviruses have been studied. The values obtained for the acid-labile foot-and-mouth disease virus increased with the duration of the centrifugation and were higher at elevated pH values. In contrast, the acid-stable enteroviruses had the same values irrespective of the time of centrifugation or the pH of the caesium solution. Viruses of intermediate stability, such as vesicular exanthema virus and the rhinoviruses, were affected in the same way as foot-and-mouth disease virus but to a smaller extent. The implications of these observations in respect of the structure of the picornavirus group are discussed.

Biochemical and biophysical properties of vesicular exanthema of swine virus

Vesicular exanthema of swine virus (VESV) was purified and some of its biochemical and biophysical properties measured. VESV grew in the presence of 2 μg/ml actinomycin D, was ether resistant, and was not stabilized by cations. Its sedimentation rate was approximately 207 S, and its composition was approximately 20% RNA and 80% protein. The RNA, which was not readily obtained in intact form, appeared to be single stranded with a molecular weight of about 2 × 10 6. Heterogeneous distributions of VESV were observed upon centrifugation in CsCl density gradients. Crude virus, or virus concentrated by differential centrifugation or by ethanol precipitation, showed a major band at 1.36 g/ml, a secondary band at 1.38 g/ml, and some infectious virus of intermediate density. Sequential treatment with ethanol and chloroform produced a sharp peak at 1.38 g/ml. Chloroform treatment in conjunction with centrifugal concentration produced a sharp band of infectious virus at an intermediate density, 1.37 g/ml, and a band of low infectivity at 1.38 g/ml. The properties of VESV were different from those of the recognized groups of viruses, but most closely resembled properties of the picornaviruses, of which poliovirus and swine enteroviruses were employed for some direct comparisons in these studies.

Biochemical and biophysical characteristics of vesicular exanthema virus and the viral ribonucleic acid.

The properties of three strains of VEV have been examined in an attempt to define its place in the classification of animal viruses. Each strain grew to high titre in a pig kidney cell line, IB-RS-2, was resistant to lipid solvents and pH 5 and could be purified by precipitation with ammonium sulphate, differential ultracentrifugation, detergent treatment and sedimentation in a sucrose gradient. The purified viruses had sedimentation coefficients in sucrose gradients of 160–170S and densities in caesium chloride ranging from 1.370 to 1.377 g/ml. In the electron microscope the 35–40 mμ particles had an appearance very similar to that described for the feline picornaviruses. Infectious RNA was obtained from each of the strains by extraction with 1% sodium deoxycholate and phenol. The infectivity of the RNA was destroyed by trace amounts of ribonuclease, indicating that the RNA is single-stranded. Labelled RNA prepared from32P-virus sedimented in a sucrose gradient at 35–38S and was disrupted into slowly sedimenting molecules by incubating with 0.01 μg ribonuclease per ml prior to centrifugation. The percentage distribution of32P in the four nucleotides was adenylic acid 29.0: cytidylic acid 25.1; guanylic acid 20.6; uridylic acid 25.3.

Electron microscopic studies on the vesicular exanthema of swine virus: II. Morphogenesis of VESV type H 54 in pig kidney cells

The morphogenesis of vesicular exanthema of swine virus (VESV), type H 54, was studied in pig kidney cells. Virus particles first appeared free in the cytoplasm of infected cells 4 hours after infection. At 7 hours after infection, virus particles were seen associated with cytoplasmic cisternae. There was a close temporal correlation between the appearance of free and cisternae-associated virus particles with the emergence of specific viral antigen and infectious virus. Cisternae-associated virus particles appeared on the cell surface 12–14 hours after infection, at a time when the titer of extracellular virus was beginning to rise. Crystalline arrays of virus particles were observed in the cytoplasm of infected cells as early as 8 hours after infection.

The influence of cations on the thermal inactivation of vesicular exanthema of swine virus.

The influence of cations on the thermal inactivation of vesicular exanthema of swine virus.

Hand-foot-and-mouth disease in a father and son

Hand-foot-and-mouth disease is a highly infectious condition characterized by maculopapular and vesicular exanthema of the extremities and diaper area, with “aphthous-like” lesions of the mouth located anterior to the fauces. Although usually it is a mild clinical entity of short duration, a Coxsackie A-16 infection may lead to serious consequences, including death in infants. Three Coxsackie Group A. Type 16, viruses were isolated from a father and son. The viruses were obtained from the stools of each patient and from the lesions on the foot of the father. All strains were isolated in suckling mice and cultures of primary rhesus monkey kidney cells. The two stool isolates were recovered also in primary cultures of Vervet kidney cells. In one patient studied, there was a diagnostic rise in titer of neutralizing antibody to the virus. This report may be the first fully documented case history of this disease in an English-language dental journal.

A study of the cellular pathogenesis of vesicular exanthema of swine virus in pig kidney cells.

Journal Article A Study of the Cellular Pathogenesis of Vesicular Exanthema of Swine Virus in Pig Kidney Cells Get access Yuan Chung Zee, Yuan Chung Zee From the Naval Biological Laboratory, University of California School of Public Health, Berkeley, California 94704 Search for other works by this author on: Oxford Academic PubMed Google Scholar Adeline J. Hackett, Adeline J. Hackett From the Naval Biological Laboratory, University of California School of Public Health, Berkeley, California 94704 Search for other works by this author on: Oxford Academic PubMed Google Scholar S. H. Madin S. H. Madin From the Naval Biological Laboratory, University of California School of Public Health, Berkeley, California 94704 Search for other works by this author on: Oxford Academic PubMed Google Scholar The Journal of Infectious Diseases, Volume 117, Issue 3, June 1967, Pages 229–236, https://doi.org/10.1093/infdis/117.3.229 Published: 01 June 1967 Article history Received: 03 December 1966 Published: 01 June 1967

Development of plaque assay for vesicular exanthema of swine virus (VESV) under methyl cellulose overlay.

A plaque assay method, using 1.05% methyl cellulose overlay, was developed for vesicular exanthema of swine virus (VESV) types A48, H54, I55, and K54. The validity of this plaque method as an assay system was upheld by the well correlated dose response, and the specificity of plaque formation was demonstrated by the fact that a specific antiserum could reduce the plaque count by more than 98%. The concentration of methyl cellulose exerted an influence on the size of plaques formed by the virus, showing an inverse relationship between concentration of methyl cellulose in the overlay medium and plaque size. Adsorption of VESV to monolayers of pig kidney cells at 37° C was found to reach a maximum within 60 minutes.

In vivo and in vitro studies of plaque type mutants of an RNA virus

Six plaque types all belonging to the same antigenic group (E54) of vesicular exanthema of swine virus (VESV) were studied for mutational changes in swine and in pig and canine cell cultures. The plaque types differed in virulence, the largest in size being the most virulent and the smallest the least virulent type. Neutralization tests revealed that only animals which showed frank disease developed specific viral antibodies. The inoculated type was generally mixed with other plaque types after recovery from the host. The contaminating new types were not the same for the different plaque type inoculations. Similar changes were observed in the two types of cell cultures. Since all inocula consisted of virus from single cell yields which were clonal in origin, it was concluded that mutational changes occurredin vivo andin vitro. Such mutations, together with the requisite selective forces, could lead to erroneous classification of a variant in regard to virulence.

Demonstration of inapparent heterogeneity in a population of an animal virus by single-burst analyses

Single-burst analyses and standard plaque assays were performed on populations of plaque types of vesicular exanthema of swine virus (VESV). The plaque assay method yielded 1% of a minute type in one of the experimental populations. When the same virus population was analyzed by single-burst experiments, up to 23% of the bursts yielded only the minute type. When one plaque type was grown en masse, other types appeared as contaminants. Two new plaque types not previously discovered in standard plaque assays were also recovered as homogeneous populations from single bursts. Experiments conclusively excluded the hypothesis of host-induced modifications as an explanation for the discrepancies between the results of the two methods of analyzing virus populations. It was concluded that some of the plaque morphology mutants of VESV have a low plating efficiency under the standard conditions of plaque assay.

THE PHOTODYNAMIC EFFECTS OF ACRIDINE ORANGE ON AN RNA VIRUS (VESICULAR EXANTHEMA)*

SummaryFree vesicular exanthema of swine virus (VESV) suspended in an acridine orange (AO) solution is not light sensitive. The simultaneous introduction to the host of AO and VESV results in progeny that are sensitive to light. The introduction of AO during the eclipse period of viral growth results in progeny sensitive to light. Introduction of AO during the exponential rise in the production of mature virus, however, results in some light sensitive particles among a majority of insensitive particles. The data presented show that the lethal effect of AO is produced only after light exposure, indicating that the mutagenic action of the dye may not be due to its presence per se.

The cellular changes produced by two variants within type E54 of vesicular exanthema of swine virus in tissue culture.

The cytopathology produced by two plaque-type variants within one antigenic type of vesicular exanthema of swine virus has been correlated with the production of infectious virus. The large-plaque former can be distinguished from the minute-plaque former by the morphologic alterations found in the nucleolus and at the cell periphery of the host cell. Cells producing both variants of the virus undergo both types of cytopathic changes. Cells in mitosis are blocked at metaphase by each variant of the virus.

Biological characteristics of two plaque variants of vesicular exanthema of swine virus, type E 54

Two lines of vesicular exanthema virus have been isolated which differ from each other in the size of the plaque produced. Several of the in vitro biological characteristics of these lines have been examined, to account for the difference in size. The minute variant was adsorbed more rapidly than the large variant to swine kidney cells and also multiplied more rapidly within these cells. Ninety per cent of the virus produced was cell associated. Average yields per cell were in excess of 1000 plaque-forming units with both variants grown at pH 8. In multicyclic growth the concentration of bicarbonate affected the amount of virus produced by infected cells, and the pH of the medium affected the release of virus after maturation. At pH 7 the release of the minute variant was small and extracellular virus was only 1–10% of that which remained in or attached to the cells as long as 20 hours after the peak of virus growth. Release of the large-plaque variant from the cells was more rapid and more complete both at acid and alkaline pH levels. Stability of the large variant at 36° was greater at pH 7 and 8. The differences in rate and efficiency of release of virus from infected cells and in pH stability are believed to account, in part, for the observed difference in plaque morphology.

Purification of animal viruses with Zn(OH) 2

A simple and rapid means for purification of three animal viruses is described. Vesicular stomatitis virus, vesicular exanthema virus, and infectious rhinotracheitis virus were all precipitated quantitatively with Zn(OH) 2. The zinc hydroxide-virus complex was then dissociated by ethylene-diaminetetraacetic acid. Approximately 90% of the nonspecific nitrogen was eliminated by this method from crude vesicular stomatitis virus suspensions. There appears to be a direct relationship between concentration of Zn(OH) 2 and the amount of vesicular stomatitis virus recovered. The virus was removed quantitatively by 0.05% Zn(OH) 2 from a preparation containing 10 7 plaque-forming units per milliliter. A high-titered preparation of vesicular exanthema virus was obtained after precipitation by Zn(OH) 2 and subsequent high-speed centrifugation. An electron micrograph of the purified preparation revealed spherical particles 55 mμ in diameter. The ratio of these particles to plaque count was approximately 200:1. The observed sedimentation rate of about 140 Svedberg units is compatible with the size shown by electron microscopy.

Plaque Morphology and Pathogenicity of Vesicular Exanthema Virus

Plaque Morphology and Pathogenicity of Vesicular Exanthema Virus

I. Cultivation of vesicular exanthema virus in vitro using pig embryo tissues.

Summary and ConclusionsA rapid, simple, and inexpensive method of propagating vesicular exanthema virus of swine was accomplished in a medium of Baker's fluid containing minced swine embryos harvested from sows in the third to the fifth week of gestation.

Vesicular exanthema in the United States; some epidemiologic aspects of the disease.

Vesicular Exanthema in the United States—Some Epidemiologic Aspects of the Disease Affiliation R. A. Bankowski CopyRight https://doi.org/10.2105/AJPH.44.9.1119 Published Online: August 29, 2011

In vitro cultivation and cytopathogenicity of vesicular exanthema virus.

Discussion and ConclusionsAn agent capable of producing typical vesicular exanthema in swine has been propagated through 16 passages in a swine embryo tissue culture system. In the course of these passages the original material has been diluted to 10-19, so that it is highly unlikely that any infective material from the original inoculum was carried through all 16 passages. Multiplication of this agent in tissue culture was accompanied by extensive degeneration of epithelial cellular outgrowths which thus provided a simple means for in vitro assay of this virus. Considerable investigation is still required to determine the sensitivity and reliability of the system of tissue culture assay, whether in swine embryonic tissues or adult tissues such as kidney epithelium. Preliminary experiments have indicated that plaque formation on swine kidney epithelium using the method of Dulbecco7 is feasible.Evidence that the cytopathogenic agent was in fact the B type of the virus of vesicular exanthema was provided by...