title: Characterization and serotype distribution of Aggregatibacter actinomycetemcomitans isolated from a population of periodontitis patients in Spain.
abstract: OBJECTIVE
  There is no study characterizing the variability of Aggregatibacter actinomycetemcomitans isolates in periodontitis patients in Spain. It is therefore the aim of this investigation to study the serotype distribution of A. actinomycetemcomitans strains isolated from periodontitis patients in Spain. The polymorphism of the genes that codifies the leukotoxin and the operon of the cytolethal-distending toxin (cdt) will also be investigated.
  
  
  METHODS
  From a total of 701 patients samples, 40 A. actinomycetemcomitans-positive periodontitis patients were included in the study (mean age 45.3, 62.5% females) and their clinical periodontal status was assessed. On average, 1-3 isolates from each patient were sub-cultured and characterized by PCR.
  
  
  RESULTS
  Using culture the prevalence of A. actinomycetemcomitans was 5.7%. The most frequent serotype was "b", being 30 patients infected by a unique serotype, while 7 patients showed co-colonization, mostly with serotypes "a" and "b". From the 79 pure isolates obtained, 24 were from serotype "a", 30 from serotype "b", 12 from serotype "c" and 4 from serotype "d". Further characterization of these samples showed that none of these 79 isolates demonstrated the 530-bp deletion in the leukotoxin's promoter region that characterizes the JP2 strain. Conversely 65.8% of the isolates were cdt+.
  
  
  CONCLUSIONS
  The most common serotypes were "a" and "b", being serotype "b" the most prevalent in mono-colonization, while serotypes "e" and "f" were not detected. In the majority of samples, operon that codifies the cdt (65.8%) and the genes responsible for the codification of leukotoxin (100%) were found. None of the isolates were JP2 strains.
authors.affiliation: Section of Periodontology, Faculty of Odontology, University Complutense, Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Mínguez
authors.affiliation: Section of Periodontology, Faculty of Odontology, University Complutense, Madrid, Spain.
authors.forename: Xiana
authors.initials: X
authors.lastname: Pousa
authors.affiliation: Section of Periodontology, Faculty of Odontology, University Complutense, Madrid, Spain; ETEP (Etiology and Therapy of Periodontal Diseases) Research Group, University Complutense, Madrid, Spain. Electronic address: davidher@ucm.es.
authors.forename: David
authors.initials: D
authors.lastname: Herrera
authors.affiliation: Laboratory of Research, Faculty of Odontology, University Complutense, Madrid, Spain.
authors.forename: Andrea
authors.initials: A
authors.lastname: Blasi
authors.affiliation: Laboratory of Research, Faculty of Odontology, University Complutense, Madrid, Spain.
authors.forename: Mari Carmen
authors.initials: MC
authors.lastname: Sánchez
authors.affiliation: Laboratory of Research, Faculty of Odontology, University Complutense, Madrid, Spain.
authors.forename: Rubén
authors.initials: R
authors.lastname: León
authors.affiliation: Section of Periodontology, Faculty of Odontology, University Complutense, Madrid, Spain; ETEP (Etiology and Therapy of Periodontal Diseases) Research Group, University Complutense, Madrid, Spain.
authors.forename: Mariano
authors.initials: M
authors.lastname: Sanz
mesh_terms: D000328:Adult; D016976:Aggregatibacter actinomycetemcomitans / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010518:Periodontitis / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D012703:Serotyping; D013030:Spain
chemical_list: D004269:DNA, Bacterial
keywords: Aggregatibacter actinomycetemcomitans; Periodontitis; Polymerase chain reaction; Serotype; Spain