(P-412) Antimicrobial Resistance in Endodontic Infections in Latin America (MICROBE-DENT): Systematic Review

Background: Although the use of antibiotics might quell endodontic infections, bacteria have either become naturally resistant to them or developed resistance by mutation due to selective pressure over the years. Knowledge of the resistance profile of microorganisms present in endodontic infections should guide the appropriate use of antibiotics.

Objectives: To identify and to characterize the circulating bacteria isolated from endodontic infections in Latin America as well as their antibiotic resistance profile.

Methods: This systematic review included randomized clinical trials, cross-sectional studies and case series. Inclusion criteria were as follow: patients with pulp necrosis and/or apical periodontitis. The protocol was registered in PROSPERO (CRD42018077810). The bibliographic search included all publications without language restrictions from January 2013 to June 2020 in the following electronic databases: Ovid MEDLINE, Ovid Embase, BVS, CINAHL, Web of Science, Cochrane Central Register of Controlled Trials. The search for gray literature was also included. “The Joanna Briggs Institute” tool was used to assess the risk of bias in the included studies. The findings were summarized in descriptive analysis.

Results: Five studies were included (N=157 teeth in 157 patients) that evaluated the antibiotic resistance of nine bacteria species in Brazil and Mexico. In primary infection, the antibiotics that showed the least clinical efficacy were erythromycin (100% resistance) for Fusobacterium nucleatum and benzylpenicillin (20% resistance) for Prevotella intermedia/ nigrescens. In secondary or persistent infection, Enterococcus faecalis showed a high rate of resistance to azithromycin (66.7%), clindamycin (70%), erythromycin (75%), gentamicin (75%), metronizadol (95%) and rifampicin (75%). The resistance genes found were blaTEM-1, ermC, tetM and tetW. In secondary or persistent infection, virulence factors that contribute to increase antimicrobial resistance have also been reported. The level of confidence in the quality of the studies was critically low. The inconsistency of the data extracted from the articles did not allow meta-analysis pooled estimate.

Conclusions: The same bacteria species present in both primary and secondary or persistent infection and were resistant to at least one of the tested antibiotics. Studies with better design and robust methodology are required to check the prevalence of antimicrobial resistance in endodontic infections in Latin American countries.