Evaluation of Antimicrobial susceptibility pattern of Streptococcus mutans isolated from dental plaques to chlorhexidine, nanosil and common antibiotics

Streptococcus mutans is one of the most important leading causes of dental diseases worldwide and is considered as one of the main causative agent of dental caries. Increasing resistance of oral pathogens to conventional antibacterial agents has resulted to find alternative therapies to overcome resistance development problems. The aim of this study was to examine susceptibility of Streptococcus mutans isolates to some antibiotics, chlorhexidine and nanosil. The study subjects comprised of caries active individual volunteers attending the outpatient department of different dental college hospitals of Kerman. The saliva sample of 2-5 ml was collected from each individual in sterile capped bottles and were immediately transported to the laboratory and processed for the screening of S. mutans . The specific selective media, Blood agar and Tryptone yeast cysteine media agar were used for the screening and isolation of Streptococcus mutans and incubated anaerobically at 37?C for 48 hrs. Colonies of mutans streptococci were examined under a dissecting microscope and identified by their distinctive colony morphology and biochemical tests .Mutacin production of all isolates were investigated.The isolates were tested for susceptibility to some antibiotics (penicillin, gentamycin, vancomycin, cephalotin), chlorhexidine and nanosil mouthwashes by disc diffusion method. The results showed that the majority of mutacin and non mutacin-producing isolates were more sensitive to the nanosil than antibiotics and chlorhexidine. More extensive research on the use of mouthwashes containing silver nanoparticles is suggested. DOI: http://dx.doi.org/10.3126/ijls.v9i2.12040 International Journal of Life Sciences 9 (2) : 2015; 18-21