Characteristic distribution pattern of Helicobacter pylori in dental plaque and saliva detected with nested PCR

Abstract

The precise mode of transmission and the natural reservoir for Helicobacter pylori are unknown. PCR assays have proved to be highly sensitive and speci®c and are regarded as the method of choice for detecting H. pylori DNA in the oral cavity. The aim of this study was to investigate the prevalence and distribution of H. pylori in the oral cavity. Forty-two patients undergoing gastroscopy were investigated for the presence of H. pylori in dental plaque and saliva by nested PCR, and in the stomach by the 13 C-urea breath test. Samples tested comprised dental plaque from molars, premolars and incisors and saliva. Two sets of primers homologous to the 860-bp fragment of H. pylori DNA, which have been shown previously to be highly sensitive and speci®c, were used for nested PCR. Eleven patients (26.2%) were infected with H. pylori in the stomach. H. pylori DNA was identi®ed in dental plaque samples from 41 patients (97%) and in 23 saliva samples (55%). The prevalence in dental plaque from molars, premolars and incisors was 82%, 64% and 59%, with an odds ratio of 3.18, 1.24 and 1 (reference), respectively. In conclusion, H. pylori was present in the oral cavity of 97% of tested patients, with a characteristic distribution that was independent of the infection status of the stomach. Thus H. pylori may belong to the normal oral micro¯ora.

Helicobacter pylori detection in gastric biopsies, saliva and dental plaque of Brazilian dyspeptic patients

“…They further emphasised that the location in the mouth used for the collection of the samples can influence the prevalence of the microorganism. This idea was further supported by the results of Song et al (2000), who found a prevalence of 82% in the molar region, 64% in pre-molar region and 59% in the incisor region. Loster et al (2006) suggested that this variation may be the result of dental plaques being exposed to different levels of oxygenation, which can affect colonisation by H. pylori.…”

“…These results are comparable to the results of the present study, in which there was a 95% success rate in the detection of H. pylori in the stomach. Li et al (1995) and Song et al (2000) showed a significant increase in the sensitivity of detection after using Southern blotting and also verified a high prevalence of infection.…”

“…Both authors suggested that saliva may be a method of transmission and may potentially induce gastric reinfections, which supports the results of the present study. Song et al (2000) analysed 117 samples of dental plaque from 42 patients and verified the presence of the bacterium in 68% of the samples. These results are similar to those of Liu et al (2009), who found positive samples in 59% of their subjects.…”

An evaluation of selected oral health indicators and cariogenic bacteria titer in patients with Helicobacter pylori

“…Its presence in plaque is highest in the area around the molars and lowest in the region of the premolars and incisors. 13 This fact may be due to oxygen exposure, which increases in the mesial direction, and this in turn can lead to the formation of distal niches.…”

Susceptibility of Helicobacter pylori and its urease activity to the peroxidase-hydrogen peroxide-thiocyanate antimicrobial system

“…H. pylori has been isolated successfully from the oral cavity by culture [6]. In a study employing the PCR method in which 42 patients were examined, H. pylori DNA was identi®ed in dental plaque of 97% of the patients and in the saliva of 55% of the patients, showing a distribution relatively independent of the infection status of the stomach [7].…”