Antimicrobial resistance in the subgingival microflora in patients with adult periodontitis - A comparison between The Netherlands and Spain

Background: The widespread use of antibiotics for prophylaxis and treatment of bacterial infections has lead to the emergence of resistant human patho gens. Great differences have been documented between European countries in the use of systemic antibiotics. In parallel, significant differences in le vels of resistant pathogens have been documented. Aim: To investigate whether differences in antibiotic use influence the lev el of antimicrobial resistance of the subgingival microflora of untreated p atients with adult periodontitis in The Netherlands and Spain. Method: Blood agar plates containing breakpoint concentrations of penicilli n, amoxicillin, amoxicillin and clavunalate, metronidazole, erythromycin, a zithromycin, clindamycin and tetracycline were used to determine the propor tion of bacteria from the subgingival plaque that was resistant to these an tibiotics. In the Spanish patients, statistically significant higher mean l evels of resistance were found for penicillin, amoxicillin, metronidazole, clindamycin and tetracycline. The mean number of different bacterial specie s growing on the selective plates was higher in the Spanish patients, as wa s the % of resistant strains of most periodontal pathogens. A striking diff erence was observed in the frequency of occurrence of tetracycline-resistan t periodontal pathogens. In Spain, 5 patients had greater than or equal to 3 tetracycline resistant periodontal pathogens, whereas this was not observ ed in any of the Dutch patients. Conclusions: The widespread use of antibiotics in Spain is reflected in the level of resistance of the subgingival microflora of adult patients with p eriodontitis.