SEROTYPIC DIFFERENTIATION OF ROTAVIRUSES IN-FIELD SAMPLES FROM DIARRHEIC PIGS BY USING NUCLEIC-ACID PROBES SPECIFIC FOR PORCINE VP4 AND HUMAN AND PORCINE VP7 GENES

Of 216 fecal and intestinal samples collected from nursing or weaned d iarrheic pigs in the United States and Canada, 57 were identified as g roup A rotavirus positive by RNA electrophoresis and silver staining. Fifty-seven and 52 rotavirus-positive samples were analyzed by hybridi zation with Gottfried and OSU PCR-derived gene 9 and 4 probes, respect ively. Only 17 samples were identified with either homologous VP4 (P) or VP7 (G)-coding genes or both. One rotavirus identified as G4 and P7 was similar to the previously characterized interserotype rotavirus, SB-1A. Additional hybridization analyses were performed with PCR-deriv ed probes prepared from gene 9 cDNA of the human rotaviruses Wa (G1), DS-1 (G2), and P (G3) and of the porcine rotavirus YM (G11). Eleven of 52 samples collected and analyzed from swine in Ohio, California, and Nebraska were identified as G11. No samples with G1-, G2-, or G3-type specificities were detected among the 25 of 57 rotavirus-positive sam ples analyzed with human rotavirus-derived probes. Further investigati ons with a PCR-derived gene 4 probe prepared from porcine rotavirus YM revealed hybridization specificities similar to those of the OSU gene 4 probe.