CHARACTERIZATION OF 2 DIVERGENT ADENOVIRUS 31 STRAINS

Two divergent strains of adenovirus type 31 were analyzed by neutraliz ation test and restriction endonuclease (RE) patterns in an effort to find the basis for their genetic variability. One strain, isolated fro m the throat of a child in Maryland during an upper respiratory illnes s in 1968, was partially neutralized by Ad 31 antisera (to 16-fold low er than homologous titer) while its own antiserum fully neutralized pr ototype Ad 31 virus, but shared only 9% of comigrating RE fragments wi th Ad 31 prototype (vs. 30% with Ad 18 prototype); however, PCR tests specific for the inverted terminal repeat (ITR) sequence of Ads 12 and 18 were negative. The other strain, recovered from a stool sample fro m an infant with diarrhea in Georgia in 1979, was inhibited by Ad 31 a ntiserum to within 4-fold homologous titer, but shared only 15% of com igrating fragments with Ad 31 prototype (vs. 91 % with Ad 18 prototype ); ITR-specific PCR tests with this virus were positive for Ad 12/Ad 1 8. These data suggest that both strains are from separate evolutionary lines of Ad 31 unrelated to all other isolates studied to date by RE analysis, and that the partial neutralization by prototype Ad 31 antis era might represent small mutations in the hexon gene.