Antibacterial properties of Carum copticum essential oil against Streptococcus mutans and Streptococcus sobrinus isolated from canine dental plaque

Abstract

Dental caries is amongst the most prevalent oral diseases in both humans and dogs. Streptococcus mutans and Streptococcus sobrinus (mutans streptococci) are the major cariogenic bacteria isolated from dental caries. Since these bacteria generally show resistance to common antibiotics, natural products such as plant essential oils could be a good substitute. For this study, we aimed to evaluate the antibacterial activity of Carum copticum essential oil against Streptococcus mutans and Streptococcus sobrinus. Twenty canine dental plaque samples were collected and the presence of S. mutans and S. sobrinus in the samples was confirmed using biochemical, culture and polymerase chain reaction (PCR) assays. The resistance patterns of isolates were determined using a disc diffusion method according to the Clinical Laboratory Standards Institute protocol against the following antimicrobials: chloramphenicol, tetracycline, penicillin, erythromycin, ceftriaxone, cefotaxime, vancomycin and azithromycin. The antibacterial activities of Carum copticum essential oil were based on the disc diffusion method as well on a determination of the minimum inhibitory (MIC 50 ) and minimum bactericidal concentration values. S. mutans and S. sobrinus were isolated in 8 (40%) and 2 (10%), respectively, of plaque samples. Most of these isolates were determined to display multidrug resistance patterns to the eight antibiotics evaluated. Screening of the antibacterial activity of the essential oil indicated that MIC 50 and minimum bactericidal concentration values were 20 µg/ml and 80 µg/ml, respectively, and that the zone of inhibition in the disc diffusion method ranged from 2 to 5 mm for serial concentrations of the essential oil. Based on our results, we suggest that Carum copticum essential oil exerts antibacterial effects against Streptococcus mutans and Streptococcus sobrinus and may be a useful treatment for carious lesions with bacterial aetiologies.

Molecular detection of antibiotic resistance genes in multidrug-resistant Staphylococcus aureus isolates from dog dental plaque

“…The prevalence of Streptococcus mutans and Streptococcus sobrinus in canine dental plaque was previously studied (Nouri Gharajalar & Hassanzade, 2017). These bacteria were isolated from 40% and 10% of tested samples, respectively.…”

Antibacterial Activity of Trachyspermum ammi Essential Oil Against Streptococcus mutans Isolated from Human Dental Plaques

“…Also, MIC50 and MBC values of the essential oil against S. mutans isolates were 20 µg/ml and 80 µg/ml, respectively, and the mean ± SD of zone inhibition was 5 ± 31 and 2 ± 10 for 80 µg/ml and 20 µg/ml concentrations of the essential oil, respectively. The result of this study indicated an increase in the inhibition zone with increased concentrations of T. ammi essential oil [13]. Another study assessed the antibacterial activity of T. ammi oil against the oral microbes using an agar well diffusion assay with three concentrations, 40 µl/ml, 80 µl/ml, and 100 µl/ml.…”

“…Twenty-five µl reactions comprised a ready-to-use master mix (Reddy, Sinaclone, Iran), and S mutans ATCC 25175 and S. sobrinus ATCC 33478 were included in the assays as positive controls. The amplicons were resolved by electrophoresis in 1.5% agarose gels [13].…”

“…After culturing the bacteria in BHI broth for 24 h, the turbidity of bacterial suspensions was adjusted to 0.5 McFarland standard and then cultured on the Mueller Hinton agar plates. Sterile discs were saturated with 10 µl of different antimicrobials and serial concentrations of sterile essential oil ranging from 10-80µg/ml and placed on the plates, followed by incubation anaerobically at 37 o C for 18-20 h. The inhibition zones were measured in millimeters and compared with each other [13,20].…”

Molecular Detection of Antibiotic Resistance Determinants in Lactobacillus Bacteria Isolated from Human Dental Plaques

“…Also, Nouri et al (2017) studied the prevalence of cariogenic bacteria in dog dental plaques and identified Streptococcus mutans and Streptococcus sobrinus in 8 (40%) and 2 (10%) of samples, respectively. Most of the isolates displayed multidrug resistance patterns to the antibiotics used in the study [17].…”