Ilan Shif

A new serotype of the outer capsid protein VP4 shared by an unusual human rotavirus strain Ro1845 and canine rotaviruses

The VP4 protein of human rotavirus (HRV) strain Ro1845 and canine rotavirus strains K9 and CU-1 exhibited greater than 98% amino acid identity within their group, but showed less identity with VP4 proteins of other HRV and animal rotavirus strains, the simian rotavirus strain RRV VP4 being most similar to them (90% amino acid identity). To exclude the possibility that these three strains were members of the RRV VP4 serotype P3, neutralization studies were performed using antisera to reassortant viruses containing the VP4 gene from each of Ro1845, CU-1 and RRV. The result established close antigenic similarity among the VP4 proteins of Ro1845, K9 and CU-1 and revealed only a marginal degree of similarity between the VP4 proteins of these three strains and that of strain RRV. These sequence and serological data suggest that the VP4 proteins of Ro1845, K9 and CU-1 represent a new P serotype which we propose to assign P13.

Three forms of AU-1 like human rotaviruses differentiated by their overall genomic constellation and by the sequence of their VP8*

SummaryInsight into the origin of human rotaviruses carrying the AU-1 VP4 allele was gained by examining their genomic RNA constellation using RNA–RNA hybridization and by sequencing the VP8* portion (nucleotides 1–750) of their gene 4. AU-1 like viruses isolated in Israel from children attending outpatient clinics were classified into three sub-genogroups based on RNA–RNA hybridization analysis: Subgenogroup 1 consists of two strains (Ro-5829 and Ro-5960) which belong to the AU-1 genogroup, since all their 11 segments hybridized to AU-1 segments. Subgenogroup 2 consists of one reassortant virus (Ro-5193) of which seven RNA segments hybridized to AU-1 segments and the remaining four segments hybridized to NCDV (bovine rotavirus). Subgenogroup 3 consists of four reassortant viruses (Ro-6460, Ro-6584, Ro-6784 and Ro-7044) which had a common genome constellation: only four of their RNA segments hybridized to AU-1 and the other seven segments hybridized to NCDV segments. Sequence analysis of the VP8* gene also revealed a three level pattern of homology with the AU-1 prototype and the local AU-1-like strains which was consistent with the overall genomic (RNA–RNA) constellation: Subgenogroup 1 had 98–98.1% homology with the AU-1 prototype; Subgenogroup 2 had 96.8% homology with the AU-1 prototype and 95.6–96.7% homology with Subgenogroup 1; Subgenogroup 3 had 95.3–95.6% homology with the prototype AU-1 and 93.4–94.3% homology with Subgenogroup 1. Possible evolutionary pathways are discussed.

Interferon assay in patients suspected of viral infections as a tool for rapid diagnosis. Brief report.

SummarySignificantly elevated interferon titers were found in sera and cerebrospinal fluids of patients suspected of viral infection, as compared to healthy controls. In most patients interferon was detected before serological confirmation or virus isolations.

Rotaviruses belonging to the AU-1 genogroup recovered from Israeli infants with diarrhea

SummaryThe genetic and antigenic diversity of group A rotaviruses recovered from Israeli infants has been expanded recently by the inclusion of three unusual human rotavirus strains. Two rotavirus strains (Ro-5829 and Ro-5960) were shown to be the first viruses outside Japan that resembled the AU-1 genogroup of feline like human rotaviruses in their overall genomic constellation and in the restriction pattern of their polymerase chain reaction amplified gene 4 following digestion with EcoRI. Another strain (Ro-5193) turned out to be an intergenogroup reassortant between viruses belonging to the AU-1 and the bovine genogroups and resembled in that respect similar viruses isolated from infants in Italy.

Efficiency of isolation of human rotavirus in primary african green monkey kidney cells

Out of 212 human rotavirus (HRV) containing fecal specimens, 173 (81.6%) yielded virus on first passage in primary African Green monkey kidney cells (AGMK), while additional 34 specimens, did not yield virus on first passage. However, following blind passages, 18 of the 34 yielded virus in passage levels 2-8, thus raising the overall isolation rate to 90.1%. The isolation rate of HRV strains obtained in embryonic Rhesus monkey kidney cell line (MA-104), was only 41.4%. ELISA tests performed on fluids from infected cell cultures proved to be an efficient tool to measure virus replication. No differences were encountered in the isolation rates between subgroup I and II strains, while viruses lacking the antigenic determinants of both subgroups did not grow at all. However, one of those unusual group A strains was isolated and grew well in AGMK cells. Primary AGMK and MA-104 cells supported the growth of tissue culture adapted virus most efficiently when compared with six human and primate cell types.