Prevalence of JP2 and Non-JP2 Genotypes of Aggregatibacter actinomycetemcomitans and Oral Hygiene Practice of Kenyan Adolescents in Maasai Mara

Abstract

Aggregatibacter actinomycetemcomitans is implicated in the etiology of periodontitis that affects adolescents. The monitoring and mapping of the geographic dissemination pattern of JP2 and non-JP2 genotypes of A. actinomycetemcomitans are of interest. In Africa, the highly leukotoxic JP2 genotype is known to be prevalent, particularly in north-west Africa. The aims of this study were to determine the prevalence of JP2 and non-JP2 genotypes and investigate the oral hygiene practices among adolescents living in Maasai Mara, Kenya. A total of 284 adolescents (mean age: 15.0 yrs; SD 1.1) were interviewed regarding their age, gender, medical history, and oral hygiene practice, and the number of teeth present was recorded. One subgingival pooled plaque sample from all the first molars of each participant was analyzed by conventional PCR. The mean number of permanent teeth present was 27.9 (SD: 2.0; range: 22–32; 95% CI: 27.7–28.1). Sixteen (5.6%) and two (0.7%) adolescents were positive for non-JP2 and JP2 genotypes, respectively. For the vast majority of the adolescents, the use of a toothbrush (99.3%) and toothpaste (80.1%), as well as some kind of toothpick (>60.2%), were part of their oral hygiene practice, with dental floss (0.4%) and/or mouth rinses (0.4%) rarely being used. We have, for the first time, identified Kenyan adolescents colonized with the JP2 genotype. The prevalence of the JP2 genotype of A. actinomycetemcomitans is low, a possible indicator that it spreading through human migration from North and West Africa to East Africa is a rare occasion.

Aggregatibacter actinomycetemcomitans and Aggregatibacter aphrophilus in a Kenyan Maasai Adolescent Population and Inhibition of Leukotoxic Activity by Herbal Plants Used as Part of Oral Hygiene Procedures

“…Interestingly, the detection of the JP2 genotype of A. actinomycetemcomitans in the present study population confirmed the previously reported observation [12]. By sequencing the leukotoxin promoter operon, we found the characteristic 530-bp deletion originally described by Brogan et al [7].…”

“…Using clean disposable mouth mirrors and tweezers, an oral examination was carried out to detect the status of the dentition. The methods and data from the clinical examination, as well as the field conditions, have been described previously; however, none of the clinical data are reported on in the present study [12,18].…”

“…However, no JP2 genotype of A. actinomycetemcomitans was identified [14]. Another Sudanese study discovered the JP2 genotype in one patient, who exhibited periodontitis with rapid progress [15], but the overall results from these examinations supported the notion that the presence of the JP2 genotype in East Africa is rather low [12]. Interestingly, an A. actinomycetemcomitans isolate sampled from a patient of Ethiopian origin living in Sweden was found to have an atypical 640-bp deletion in the leukotoxin gene promoter [16].…”

“…These properties of the leukotoxin are associated with the cellular and molecular mechanisms involved in the pathogenicity of periodontitis [11]. Whereas periodontitis associated with A. actinomycetemcomitans, especially in adolescents, has been studied in northern and western parts of Africa, not much is known about the presence of A. actinomycetemcomitans in eastern parts of Africa [12]. Some studies performed in Sudan have indicated a rather high degree of rapidly progressing forms of periodontitis [13,14] associated with A. actinomycetemcomitans in the Sudanese population.…”

The Highly Leukotoxic JP2 Genotype of Aggregatibacter actinomycetemcomitans Is Present in the Population of the West African Island, Sal in Cape Verde: A Pilot Study

“…In previous studies, low JP2 prevalence (0.7%) was found in Kenya [ 19 ], with higher levels in other African countries, including Morocco (7.3%) and Ghana (8.8%) [ 12 , 15 ]. Earlier studies reported a strong association between the presence of the JP2 genotype and periodontitis [ 6 , 20 ], while other studies did not find such a clear association [ 15 ].…”