Highly toxic clone of Actinobacillus actinomycetemcomitans in geographically widespread cases of juvenile periodontitis in adolescents of African origin

Abstract

The bacterium Actinobacillus actinomycetemcomitans has been implicated in the pathogenesis of juvenile periodontitis as the etiologic agent on the basis of several lines of circumstantial evidence. A matter of extensive debate is whether A. actinomycetemcomitans is an exogenous contagious pathogen or an opportunistic pathogen that resides in the normal oral microflora. Here we show evidence of a single clone of A. actinomycetemcomitans isolated from multiple patients with juvenile periodontitis in members of families of African origin living in geographically widespread areas. The clone is characterized by a 530-bp deletion in the leukotoxin gene operon, resulting in a significantly increased production of leukotoxin.

Aggressive periodontitis in children: a 14–19‐year follow‐up

“…Results from the different examinations including the presence of Aggregatibacter actinomycetemcomitans (A.a.) in the microbial samples were initially reported by Berglundh et al (2001) and are also presented in Table 1. Further analyses of the A.a. samples regarding the specific JP2 clone were subsequently performed by Haubek et al (1996). Subjects that were positive to this clone in the initial examination (patients 3, 4, 8, 9, 10 and 11) are described in Table 1.…”

Prevalence of periodontal pathogens in Brazilians with aggressive or chronic periodontitis

“…The frequency of serotype b, A. actinomycetemcomitans is elevated in Americans (Zambon et al 1983a, b, Yang et al 2004, with aggressive periodontitis, but not in Koreans (Chung et al 1989), Chinese (Wang et al 1997), or Turks (Celenligil & Ebersole 1998). The highly leucotoxic clone of A. actinomycetemcomitans more likely infects people of African descent (Haubek et al 1996(Haubek et al , 1997(Haubek et al , 2001 than in northern Europeans (Haubek et al 1995) or Chinese (Mombelli et al 1998, Wang et al 2000.…”

Aggregatibacter actinomycetemcomitans serotypes, the JP2 clone and cytolethal distending toxin genes in a Thai population

“…Subjects who were positive for A. actinomycetemcomitans were further analysed for the presence of the high leukotoxin-producing JP2 clone by PCR amplification of the ltx promoter region. The PCR primers were used as previously described (Haubek et al 1996). The PCR temperature profile was as follows: initial denaturation at 94°C for 5 min., and 30 cycles of denaturation at 94°C for 1 min., annealing at 60°C for 1 min.…”