Ribotype profiles of 10 different isolates of P. mirabilis. Lane 1, ribotype 851.4; lane 2, ribotype 851.8; lanes 3, 8, and 10, ribotype 855.7; lanes 4 and 6, ribotype 858.2; lane 5, ribotype 859.5; lanes 7 and 9, ribotype 637.8. Molecular size markers in terms of kilobase pairs are shown at the left of the figure.