Epidemiology of myxo- paramyxovirus infections among cynomolgus monkeys imported for laboratory use

An amino acid in the heptad repeat 1 domain is important for the haemagglutinin-neuraminidase-independent fusing activity of simian virus 5 fusion protein

A canine isolate (strain T1) of simian virus 5 (SV-5) performed multiple replication in BHK cells but did not induce cell fusion for up to 3 days. In contrast, a prototype strain (WR) provoked extensive cell fusion within 2 days during the course of its replication. Accordingly, the fusion (F) protein of the T1 strain did not cause cell fusion even when co-expressed with the SV-5 haemagglutinin-neuraminidase (HN) protein, whereas the WR F protein induced cell fusion in the presence of the HN protein. Differences in the predicted amino acid sequences of the T1 and WR F proteins were found at 12 positions and it was proved that the T1 F protein had a longer cytoplasmic tail than the WR F protein. By reducing the length of the cytoplasmic tail or by replacing the tail with the WR F counterpart, the T1 F protein partly restored its HN-dependent fusing activity. Chimeric and mutational analyses between the T1 F protein and the mutant F protein (L22P) suggested that Glu-132 in the heptad repeat 1 domain was involved in the HN-independent fusing activity in addition to the previously identified Pro-22 at the F(2) N terminus. It was also shown that Ala-290 in the heptad repeat 3 domain contributed to the HN-independent fusing activity to some extent.

Serological survey for SV5, measles and herpes simplex infections in newly-imported cynomolgus monkeys

On 592 cynomolgus monkeys of newly-imported 14 different groups, sero-epidemiological follow-up surveys of natural infections with SV5, measles (MV) and herpes simplex (HSV) were conducted both at the time of arrival and at the end of the 9-week quarantine period at Tsukuba Primate Center for Medical Science (TPC). At the time of arrival, the positive rate of antibodies against these viruses greatly varied with different countries of origin. As regards SV5, the positive rate ranged widely from 0 to 94.9% among different import-groups, being markedly low in the Philippine monkey groups. The positive rate of MV antibody was generally very high, varying from 11.1 to 78.2% in almost all import-groups except two groups from Indonesia in which no positive case was detected. Concerning HSV, every import-group had a very high positive rate though the average antibody titer was not so high. Generally, the positive rates of SV5 and MV markedly increased by the end of quarantine period. Especially, MV positive rate reached 100% in almost all of the import-groups. However, two Indonesian groups showed no increase of SV5 and MV positive rates during the quarantine period. No increase of SV5 positive rate was detected either with any of three Philippine groups. As for HSV, the positive rate remained unchanged or rather decreased during the quarantine period in almost all groups except two Indonesian groups having shown a significant increase.

A new Paramyxovirus isolated from cynomolgus monkeys

A new virus was isolated from cynomolgus monkeys for laboratory use imported from Indonesia in July, 1973. The virus agglutinated erythrocytes of some avian and mammalian species and hemolyzed chick erythrocytes. The virus was eluted from the surface of chick red blood cells by its neuraminidase activity. The virus was inactivated by ether; its nucleic acid was RNA. On electron micrographs, the particles varied from 250 to 400 nm in diameter, being covered with envelopes in which the surface projections were embedded. The diameter of inner helical structure was about 18 nm. These observations indicate that the virus belongs to a group of paramyxoviruses. On the basis of serological examinations, this virus can be identified as a new virus having some relations with Yucaipa or Bangore viruses. This virus is designated as "Murayama virus" from the name of the place where it was isolated.