Prevalence of Antibiotic Resistance Genes in Subjects with Successful and Failing Dental Implants. A Pilot Study

Abstract

Objectives :To investigate the prevalence of the bacterial genes encoding resistance to beta-lactams, tetracyclines and metronidazole respectively, in subjects with successful and failing dental implants and to assess the presence ofStaphylococcus aureusand themecAgene encoding for Methicillin ResistantStaphylococcus aureus(MRSA) in the same samples.Materials and Methodology:The subject sample included 20 participants with clinically healthy osseointegrated implants and 20 participants with implants exhibiting peri-implantitis. Clinical parameters were assessed with an automated probe, samples were collected from the peri-implant sulcus or pocket and analyzed with Polymerase Chain Reaction forblaTEM, tetM, tetQandnimgenes,S. aureusand MRSA using primers and conditions previously described in the literature.Results:Findings have shown high frequencies of detection for both groups for the tetracycline resistance genestetM(>30%),tetQ(>65%) with no statistical differences between them (z-test with Bonferroni corrections,p<0.05). TheblaTEMgene, which encodes resistance to beta-lactams, was detected in <15% of the samples. Thenimgene, which encodes resistance to metronidazole,S.aureusand themecAgene encoding for MRSA were not detected in any of the analyzed samples.Conclusions:Healthy peri-implant sulci and peri-implantitis cases often harbor bacterial genes encoding for resistance to the tetracyclines and less often for beta-lactams. Thus, the antimicrobial activity of the tetracyclines and to a lower extent to beta-lactams, might be compromised for treatment of peri-implantitis. Since no metronidazole resistance genes were detected in the present study, its clinical use is supported by the current findings.S.aureusmay not participate in peri-implant pathology.