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P A Bachmann

Publications and source records attributed to P A Bachmann.

16 recordsLinked to original sources
PubMed1979

Physical characterization of a stomatitis papulosa virus genome: a cleavage map for the restriction endonucleases HindIII and EcoRI.

The genome of stomatitis papulosa virus (a parapoxvirus) was cleaved with the restriction endonucleases HindIII and EcoRI, each giving rise to 6 fragments respectively. Double digestion with both enzymes resulted in 8 bands, two of which contained DNA fragments in double molar concentrations as revealed by reciprocal digests of isolated DNA fragments. The genome size, estimated by summation of the molecular weights of the fragments, is approximately 86 X 10(6) daltons, some 30 X 10(6) daltons smaller than vaccinia virus (an orthopoxvirus) DNA. The cleavage sites of HindIII and EcoRI endonucleases were mapped on the genome by analysis of reciprocal digests of isolated DNA fragments and by cross-hybridization experiments. This yielded two mapped segments which were then oriented relative to one another by cleavage of isolated partial digestion products. The terminal restriction fragments show rapid renaturation after alkali denaturation and subsequent neutralization, indicating that stomatitis papulosa virus DNA contains terminal cross-links analogous to those found in vaccinia virus DNA.

Animals↗
PubMed1979

Morphology and morphogenesis of a new paramyxovirus (PMV 107).

The morphology of the virions and nucleocapsids of paramyxovirus 107 (PVM 107) and the replication of the virus were investigated by electron microscopy. The virions and nucleocapsids exhibited the same structural properties as other paramyxoviruses. Nuclecapsids were found in the nucleus and cytoplasm of infected bovine embryonic lung (BEL) cell cultures. A similar situation has been described for the morbilliviruses measles, SSPE, distemper and rinderpest. Alignment of nucleocapsids beneath the plasma membrane and budding of PMV 107 in the productive BEL cell infections were also similar to the morbillivirus-infected cells. In a line of monkey cells (CV1) persistently infected with PMV 107 only cytoplasmic nucleocapsids could be demonstrated. On the basis of its morphology and morphogenesis it is suggested that PMV 107 should be classified as a paramyxovirus. Since nucleocapsids could also be found in the nucleus of infected BEL cells the morphogenesis of PMV 107 closely resembles that of viruses of the morbillivirus group.

Animals↗
PubMed1976

In vitro differentiation and pH sensitivity of field and cell culture-attentuated strains of transmissible gastroenteritis virus.

Characteristics of four transmissible gastroenteritis (TGE) virus field strains (Miller, Purdue, Bl, and V203) and four cell culture-attenuated strains (Purdue, SH, CKp, and Bl) were studied to find methods of differentiation between the two groups of viruses. TGE field virus strains did not replicate as well as attenuated strains at 37 C and could not be passaged serially for more than four to six passages at 33 C. There were clear differences in plaque size when the strains were compared. Field strains had average plaque sizes ranging from 3.59 to 3.15 mm, whereas attenuated strains induced plaques that were larger than 4.2 mm. Variations were observed in stability of strains at pH 3.0. Field strains and cell culture-attenuated strains CKp-270 and SH-114 were reduced in titer by about 1 log10. A reduction of about 3 log10, however, was obtained with cell culture strains B1-300 and Purdue-113.

Cell Line↗
PubMed1975

Sporadic bovine meningo-encephalitis-isolation of a paramyxovirus.

Isolation of a viral agent (107) directly from brain explants of a 15-month-old heifer with symptoms of a sporadic encephalomyelitis is described. The virus shares properties with the paramyxovirus family. It grows in a variety of cell cultures from different species, and induces nuclear and cytoplasmic inclusion bodies in infected cells. Nucleocapsids measuring 17 nm in diameter were found in the nucleus and cytoplasm of these cells when studied electron microscopically, thus indicating a close relationship of the agent to the measles-distemper-rinderpest group. No infectious virus was released from infected cells, although alignment of nucleocapsids was observed beneath the cell membrane, and no hemagglutinating activity could be detected with the methods employed. The 107 agent was compared serologically with parainfluenza viruses type 1, 2 and 3, simian virus 5, mumps and Newcastle disease virus (NDV), two bovine respiratory syncytial viruses and measles/subacute sclerosing panencephalitis, distemper and rinderpest viruses, always using 107 virus infected CV1 cells and antiserum of the different viruses in indirect FA tests. Positive FA reactions were observed only with two sera obtained from SSPE patients with high antibody titer to SSPE virus, and with one rabbit-anti-rinderpest serum. The titers of these sera to 107 virus, however, were significantly lower than those against homologous viruses. Five out of 9 sera from randomly selected healthy cattle showed antibody titers between 1:10 and 1:80 to 107 virus in FA tests. The significance of these results is discussed with respect to the epidemiology of SSPE in children and its possible implication with rinderpest in Europe.

Animals↗
PubMed1975

Experimental in utero infection of fetal pigs with a porcine parvovirus.

In utero infection of fetuses of six specific-pathogen-free large white sows at 35, 48, 55, 72, 99, and 105 days was studied. The fetuses were infected by direct inoculation of porcine parvovirus into the amniotic sac. The inoculation consisted of 0.25 ml of tissue culture fluid containing 10(5.5) mean tissue culture infective doses per ml of porcine parvovirus strain G10/1. Fetuses of one uterus horn were infected, whereas fetuses in the opposite horn were given 0.25 ml of noninfected cell culture material. No clinical signs of infection were observed; however, all sows developed antibodies 7 to 9 days postinfection. A total of 24 virus-inoculated fetuses and 20 control fetuses were studied. Fetuses infected at 35, 48, and 55 days of gestation died between about 5 and 22 days after infection. Virus was isolated from their organs and fetal blood. Virus spread to control fetuses but did not cause death and mummification or stimulate antibody production. Fetuses from sows infected at 72, 99, and 105 days of gestation survived. They developed high antibody titer in utero. Control piglets remained antibody free.

Amnion↗
PubMed1975

Parvoviridae.

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Parvoviridae↗