Comparison of randomly amplified polymorphic DNA analysis and pulsed-fieldgel electrophoresis for typing of Moraxella catarrhalis strains

Randomly amplified polymorphic DNA (RAPD) and pulsed-held gel electrophores is (PFGE) for the analysis of 13 Moraxella catarrhalis isolates, 11 success ive strains isolated from sputa of five children and 2 isolates obtained th e same day from twins, were compared. RAPD and PFGE both yielded nine types from the 13 isolates, showing a chronic colonization with one strain in th ree patients and a successive colonization with different strains in two pa tients, The promising results obtained with RAPD should be confirmed with a larger number of strains, but RAPD seems as suitable as PFGE for the typin g of M. catarrhalis.