Antimicrobial susceptibility of air-dispersed microorganisms in dental settings

To determine the number and the susceptibility of microorganisms collected in a clinical environment against the antimicrobial agents used commonly in dentistry, petri dishes containing trypticase soy agar were exposed to air in different sites of a multi-chair dental clinic before, during, and after multiple clinical procedures and incubated for 24 hours under aerobic conditions. Colonies were identified by Gram stain technique and biochemical tests. Commercial paper disks containing widely prescribed antimicrobial agents (beta-lactams, macrolides, and clindamycin) were used to perform the antimicrobial susceptibility tests. The groups (colony forming units = cfu/m2/min) were submitted to the Kruskal-Wallis test (alpha = 5.0%), considering different clinical situations and environmental sites. During clinical procedures, the number of microorganisms increased (p < 0.05). This study highlights the need for established strategies to prevent resistant bacterial strains from emerging in dental settings.