Transmissible gastroenteritis (TGE) of swine: in vitro virus attachment and effects of
polyanions and polycations.
Nguyen TD, Bottreau E, Aynaud JM
National Institute of Veterinary Research, Bachmai, Hanoi, Vietnam.
Four transmissible gastroenteritis virus (TGEV) strains (Purdue-115, D-52, 188-SG and Gep-II) and two cell lines (swine testis-ST and pig kidney-RPD) were used to study virus attachment and cell susceptibility. Virus attachment was partially thermodependent and the rate varied, depending on the strain. Identical TGEV inocula produced a higher plaque number by plaque assay in the swine testis cell line (ST) than in the pig kidney cell line (RPD) but [3H]uridine-labelled virus was found associated equally well with both cell lines. A field TGEV strain (Gep-II), which was unable to multiply in cell cultures, appeared able to inhibit the attachment of radiolabelled cell-passaged virus. Therefore, the susceptibility to TGEV infection was apparently not determined at the virus-to-cell attachment stage. The attachment sites on the cell surface were specific, however, differences in TGEV attachment determinant between strains were not observed. Attachment of all the virus strains tested was enhanced by DEAE-dextran and inhibited by dextran sulfate, poly-L-lysine (PLL), poly-L-alpha-ornithine (PLO) and protamine sulfate.
[Influence of concanavalin A on the attachment of the coronavirus of transmissible
gastroenteritis in cell cultures].
[Article in French]
Nguyen TD, Bottreau E, Aynaud JM
INRA, Laboratoire de Pathologie Porcine, Nouzilly, France.
Effect of Concanavalin (ConA) on attachment of three strains of Transmissible Gastroenteritis coronavirus (TGE) of swine was investigated in cell culture. Whatever the virus strain, reduction of virus plaques number is observed when viral suspension is incubated with cells together or after addition of ConA. Intensity of inhibition is related with ConA concentration. ConA treatment of preinfected cell cultures has no effect on plaque formation. Addition of alpha-methyl-D-mannoside inhibits the ConA activity. Treatment of cells with metaperiodate has no effect on plaque formation and ConA activity. Our results suggest that ConA inhibits formation of plaques by TGE coronavirus.
Neutralizing secretory IgA and IgG do not inhibit attachment of transmissible gastroenteritis
virus.
Nguyen TD, Bottreau E, Bernard S, Lantier I, Aynaud JM
INRA, Laboratoire de Pathologie Porcine, Nouzilly, France.
Secretory IgA (sIgA) and IgG from porcine milk and serum, respectively, [3H]uridine-labelled virus, swine testis and pig kidney cell lines were used to examine the neutralized virus-cell interaction. Transmissible gastroenteritis virus (TGEV), 99.99% neutralized by immunoglobulin, was able to attach to the cells. Moreover, sIgA enhanced virus attachment. However, the neutralized virus was unable to enter cells, as demonstrated by the action of proteinase K which removed it from the cell surface. It was also found that pre-attached virus was still neutralizable and that IgG and sIgA had similar TGEV-neutralizing capacities.
Transmissible gastroenteritis (TGE) of swine: survivor selection of TGE virus mutants in
stomach juice of adult pigs.
Aynaud JM, Nguyen TD, Bottreau E, Brun A, Vannier P
INRA, Laboratoire de Pathologie Porcine, Nouzilly, France.
Two transmissible gastroenteritis (TGE) virus mutants (188-SG and 152-SG) were obtained from a low-passage virus strain (D-52) by 188 and 152 cycles of stomach juice treatment and multiplication in cell culture. Compared to the high-passage Purdue-115 and the original D-52 strains, these mutants were more stable at pH 2.0, more resistant to pepsin and trypsin, and characterized by a small plaque phenotype. In vivo, the two mutants were not found to be virulent for 4-day-old piglets and sows after oral inoculation. To test induction of lactogenic immunity, the 188-SG mutant was administered orally to pregnant sows (6 or 7 weeks before parturition) followed by one intramuscular booster (1 week before parturition). After challenge with virulent TGE virus, piglet mortality 7 days after exposure was reduced (to 22%) as compared to the death rate in piglets from control sows (91%).
Effect of antibiotics on the development of immune response in the organism
of animals. IV.
Rabbit experiments with a Brucella vaccine (B19) and its heat-inactivated
variant.
Tran DT
Hungarian Veterinary Institute.
Summary not available.
Effect of antibiotics on the immune system of animals. III. Experiments in
pgis immunized
with live and inactivated swine erysipelas vaccines.
Tu TD
Hungarian Veterinary Institute.
Summary not available.
Effects of antibiotics on the immune system of animals. II. Mouse
experiments with an
inactivated adsorbed vaccine against swine erysipelas.
Tu TD
Hungarian Veterinary Institute.
Summary not available.
Effects of antibiotics on the immune system of animals. I. Mouse experiments
with the low-virulence VR2 strain of Erysipelothrix rhusiopathiae.
Tu TD
Hungarian Veterinary Institute.
Summary not available.
A gosling disease in Viet-Nam.
Hanh NV
Hungarian Veterinary Institute.
Summary not available.
