TYPING OF HUMAN GROUP-A ROTAVIRUS WITH ALKALINE PHOSPHATASE-LABELED OLIGONUCLEOTIDE PROBES OR A MONOCLONAL ENZYME-IMMUNOASSAY IN UNFROZEN STOOLS OF CHILDREN WITH DIARRHEA IN BANGKOK

In developed countries, serotypes (or G types) have been identified in >70% of group A rotavirus using monoclonal enzyme immunoassays (MEIAs ); however, these assays have identified <50% of rotavirus G types fro m developing countries presumably because the VP7 antigens were damage d by freezing and thawing during transportation of specimens. The VP7 (G) serotypes of rotavirus in unfrozen stool collected from children w ith acute diarrhea in Bangkok were determined using MEIA and compared to hybridization with alkaline phosphatase-labeled oligonucleotide pro bes. Reverse transcription of dsRNA coding for VP7 followed by polymer ase chain reaction amplification of cDNA was used as an additional ste p prior to hybridization for 98 specimens that did not hybridize with the oligonucleotide probes. Of 251 rotavirus specimens, 208 (83%; 99% Cl = 76-89%) hybridized with G type specific oligonucleotides compared to 146 (58%; 99% Cl = 50-66%) that were trypeable by MEIA. Forty-five (82%) of 55 stools containing G type 1, 80 of 84 (95%) containing G t ype 2, 0 of 3 containing G type 3, and 2 of 4 (50%) containing G type 4 as identified by MEIA hybridized with G type specific oligonucleotid es. Differences in nucleotide sequences coding for VP7, in addition to destruction of the VP7 antigen by freezing and thawing of the specime n, may explain why not all rotavirus hybridized with G type specific p robes. (C) 1995 Wiley-Liss, Inc.