Molecular analysis of a new insertion sequence from Actinobacillus (Haemophilus) actinomycetemcomitans FDC Y4.

ABSTRACT

We have found a new insertion sequence (IS), designated ISAa1, downstream of the S10 operon in Actinobacillus (Haemophilus) actinomycetemcomitans FDC Y4. ISAa1, the first IS element characterized in this organism, is 705 bp long and lacks terminal inverted repeats. This element displayed significant homology with IS200. Hybridization patterns of genomic DNA of seven A. actinomycetemcomitans strains with an internal ISAa1 probe varied depending on the serotypes, suggesting that ISAa1 might be a useful tool for epidemiological studies.