Prevalence of β-lactam (bla_TEM) and Metronidazole (nim) Resistance Genes in the Oral Cavity of Greek Subjects

The aim of this study is to investigate the prevalence of bla_TEM and nim genes that encode resistance to β-lactams and nitroimidazoles, respectively, in the oral cavity of systemically healthy Greek subjects.

After screening 720 potentially eligible subjects, 154 subjects were recruited for the study, including 50 periodontally healthy patients, 52 cases of gingivitis and 52 cases of chronic periodontitis. The clinical parameters were assessed with an automated probe. Various samples were collected from the tongue, first molars and pockets >6mm, and analysed by polymerase chain reaction-amplification of the bla_TEM and nim genes, using primers and conditions previously described in the literature.

There was a high rate of detection of bla_TEM in plaque and tongue samples alike in all periodontal conditions (37% of plaque and 60% of tongue samples, and 71% of participants). The bla_TEM gene was detected more frequently in the tongue samples of the periodontally healthy (56%) and chronic periodontitis (62%) groups compared to the plaque samples from the same groups (36% and 29%, respectively; z-test with Bonferroni corrections-tests, P<0.05). The nim gene was not detected in any of the 343 samples analysed.

The oral cavity of Greek subjects often harbours bla_TEM but not nim genes, and therefore the antimicrobial activity of β-lactams might be compromised.