Resistance of Pseudomonas aeruginosa isolated from Dental Canal to Commercial Antibiotics

Abstract

Introduction: Pseudomonas aeruginosa is an opportunistic gram-negative bacterium widely in hospital environments, soil, and water. It is known for its multidrug resistance to antimicrobials. It is commonly associated with pneumonia, urinary tract infections, and burns. Objective: to analyze the sensitivity profile of oral clinical isolates of P. aeruginosa to commercial antibiotics. Methodology: oral clinical isolates of P. aeruginosa were cultured on Nutrient Agar and adjusted to 0.5 McFarland standard. Susceptibility to commercial antibiotics was tested using the disk diffusion test. Mueller-Hinton Agar plates were inoculated with the bacterial strains, and disks impregnated with different commercial antibiotics were placed on the plates. After incubation at 37°C for 18-24 hours, the inhibition zones around the disks were measured in millimeters. Results were interpreted by CLSI criteria to classify strains as resistant (R), susceptible (S), or susceptible with increased exposure (SA). Results: P. aeruginosa isolates demonstrated sensitivity to Ciprofloxacin and Ceftazidime, presenting inhibition zones within the parameters considered sensitive and sensitive with increased exposure by BrCAST-EUCAST. For Amikacin, they presented controversial results, such as the isolates (S), (SA), and (R). The isolates were resistant to Amoxicillin, Azithromycin, and Aztreonam. Polymyxin could not be evaluated according to the BrCAST criteria. Discussion: multiple resistance of Pseudomonas aeruginosa to antibiotics compromises the treatment of infections, requiring rational use and genomic surveillance. Conclusion: the results showed resistance to different antibiotics, highlighting the complexity of treating infections caused by these bacteria.

Keywords: Microbial Sensitivity Tests; pseudomonas infection; drug resistance