MULTIPLE ADENOVIRAL SEROTYPES DEMONSTRATE HOST-RANGE EXTENSION IN THENEW-ZEALAND RABBIT OCULAR MODEL

PURPOSE. Although several human adenoviral serotypes demonstrated the genetic capability of replicating in New Zealand rabbit corneas in org an culture, only a single adenovirus (Ad) serotype, Ad5, has been repo rted to replicate in vivo in New Zealand rabbit eyes. The purpose of t his study was to determine whether additional adenoviral serotypes cou ld extend their host range to the New Zealand rabbit ocular model. MET HODS. Six rabbits per vial isolate were inoculated in each eye after c orneal scarification with 1.5 X 10(6) plaque-forming units per eye wit h one of the following reference or clinical adenovirus isolates: Ad1 ATCC, Ad1 Kmetz, Ad2 ATCC, Ad2 Wolf, Ad5 ATCC, Ad5 McEwen, Ad6 ATCC, A d19 ATCC, and Ad8 Cray (five rabbits). Eyes were cultured on days 0, 1 , 3, 4, 5, 7, 9, 11, 14, 16, 18, and 21 after inoculation, and their t ear film viral titers were determined on A549 cells. RESULTS. Ad19 ATC C and Ad8 Cray demonstrated no apparent viral replication. The mean du ration of shedding was 1.5 and 0.3 days, respectively, and the total p ercentage of Ad-positive eyes was 13% and 3%, respectively. In contras t to Ad19 ATCC and Ad8 Cray, all other isolates demonstrated productiv e infection. The mean duration of shedding was 8 to 16 days (P < 0.000 1), and the total percentage of Ad-positive eyes was 33% to 79% (P < 0 .0002). The durations of shedding for Ad1 ATCC, Ad1 Kmetz, Ad2 ATCC, A d2 Wolf, and Ad6 ATCC did not differ statistically from Ad5 McEwen, wh ereas Ad5 ATCC demonstrated a duration of shedding longer than all iso lates (P < 0.001). CONCLUSIONS. This was the first demonstration of ho st range extension by additional clinical and reference isolates of ad enovirus types 1, 2, 5, and 6 in the New Zealand rabbit ocular model. These results suggested that host specificity was less stringent than previously thought.