title: Intragenomic recombination in the highly leukotoxic JP2 clone of Actinobacillus actinomycetemcomitans.
abstract: The highly leukotoxic JP2 clone of Actinobacillus actinomycetemcomitans is strongly associated with aggressive periodontitis in adolescents of African descent. DNA fingerprinting using the frequently cutting restriction enzyme MspI and multilocus sequence typing (MLST) showed that five strains of this clone were genetically virtually identical, although ribotyping of the six rrn genes and EcoRI RFLP analysis of the seven IS150-like elements revealed differences. PCR analyses demonstrated that these multi-copy sequences are subject to intragenomic homologous recombination, resulting in translocations or large inversions. The genome rearrangements were reflected in differences among 25 strains representing the JP2 clone in DNA fingerprinting using the rare-cutting restriction enzyme XhoI and resolved by PFGE. XhoI DNA fingerprinting provides a tool for studying local epidemiology, including transmission of this particularly pathogenic clone of A. actinomycetemcomitans.
authors.affiliation: Institute of Medical Microbiology and Immunology, University of Aarhus, Denmark.
authors.forename: Kirsten T
authors.initials: KT
authors.lastname: Eriksen
authors.affiliation: Department of Community Oral Health and Pediatric Dentistry, University of Aarhus, Denmark.
authors.forename: Dorte
authors.initials: D
authors.lastname: Haubek
authors.affiliation: Institute of Medical Microbiology and Immunology, University of Aarhus, Denmark.
authors.forename: Knud
authors.initials: K
authors.lastname: Poulsen
mesh_terms: D000189:Actinobacillus Infections / Q000382:microbiology; D000293:Adolescent; D016976:Aggregatibacter actinomycetemcomitans / Q000145:classification* / Q000235:genetics*; D010520:Aggressive Periodontitis / Q000382:microbiology; D002999:Clone Cells; D016172:DNA Fingerprinting / Q000379:methods; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D016521:Electrophoresis, Gel, Pulsed-Field; D005098:Exotoxins / Q000378:metabolism*; D016680:Genome, Bacterial; D006801:Humans; D012150:Polymorphism, Restriction Fragment Length; D011995:Recombination, Genetic; D021521:Ribotyping
chemical_list: D005098:Exotoxins; C018579:leukotoxin; C034510:CTCGAG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific