Homologous interference by avian infectious bronchitis virus, inhibition of plaque formation of the Beaudette-42 strain by mixed inoculation with the KH strain.

Inhibition of plaque formation by avian infectious bronchitis virus (IBV) Beaudette-42 (Be-42) strain occurred in chick kidney cells with the inoculation of the same cell culture with the KH strain of IBV. For the complete inhibition of approximately 10(2) plaque-forming units (pfu) of the Be-42 strain, at least 10(5) pfu of the KH strain was required. The KH strain would inhibit plaque formation by the Be-42 strain if used as long as six hours after the inoculation of the Be-42 strain. The inactivated KH strain did not inhibit the plaque formation of the Be-42 strain.