The efficacy of anti-microbial agents against Actinomyces species isolated from patients with dental caries

Introduction
Destruction of teeth is a serious problem in oral and general health of the human being, and dental caries is one of the major defects of dental hard tissue. OBJECTIVES: The objective of this research was to isolate Actinomyces species from dental caries using polymerase chain reaction technology, and to examine the in vitro antibiotic resistance of isolates using a specific 16S rRNA primer to investigate the effect of several anti-bacterial agents, such as amikacin, gentamicin, ciproflo­xacin, amoxicillin, ceftriaxone, cefixime, vancomycin, and erythromycin against Actinomyces species.

Material and methods
Eighty samples from dental carious lesions were collected and tested for the current study between March and June, 2021. GP-ID cards with 64 biochemical tests were utilized in the automated Vitek-2 Compact system to confirm bacterium isolates. The basis of polymerase chain reaction technology was DNA polymerase’s capacity to manufacture a new DNA strand. Kirby-Bauer disc diffusion method was applied to examine the in vitro antibiotic resistance of isolates taken from dental caries using a specific 16S rRNA.

Results
Actinomyces meyeri and A. viscosus were detected with 16S rRNA genes using PCR technique. All 18 (100%) A. meyeri identified by Vitek-2 system provided positive results for specific 16S rRNA gene at 519 bp, and all 19 (100%) A. viscosus identified by Vitek-2 system provided positive results for specific 16S rRNA gene at 787 bp. The use of selective antibiotic tests, such as amikacin, gentamicin, ciprofloxacin, amoxicillin, ceftriaxone, cefixime, vancomycin, and erythromycin demonstrated the impact of antibiotics against A. meyeri and A. viscosus isolates.

Conclusions
The detection of Actinomyces spp. with the use of PCR analysis appears to be extreme accurate. Amoxicillin should be considered as the first choice antibiotic for Actinomyces spp.