finally , a hypothesis is put forward to explain the fact that no significant changes were found in the sensitivity of dutch gonococcal strains to am , p , t , ri , sp , su , and tr in the period from 1967 to 1972 , while the s strains ( which may be regarded as imported ) showed a significantly higher percentage of strains relatively resistant to am , p , t , ri , and tr .
C0018081
gonococcal
C0002680
am