Studies on ampicillin resistant plasmid of Streptococcus mutans isolated from dental caries patients

Dental caries is a well known major oral health problem in most countries. The multifactorial etiology of the disease includes multiple bacterial species, S. mutans is the main pathogen associated with the disease. Streptococcus mutans is recognized as the main pathogen of dental caries in human beings. One of the important virulence properties of S. mutans is their ability to form biofi lms on tooth surfaces which make them a primary an etiological agent in dental caries. This bacterium allows the colonization of other microorganisms resulting in dental plaque. Recently multi drug resistant species of S. mutans were identifi ed from the dental caries patients against many commercial antibiotics. Several therapeutic agents are available to treat or prevent tooth decay, but none of them showed complete sensitivity and have signifi cantly infl uenced the disease’s global burden. Totally, fi fty extracted tooth samples with chronic dental caries were selected for this study. The effectivity of caries was determined by the caries susceptibility test. S. mutans, the predominant cariogens were isolated from dental caries patients. Ten antibiotics (Penicillin-G, Ampicillin, Cefaclor, Tetracycline, Erythromycin, Chloramphenicol, Ciprofl oxacin, Amoxicillin, Vancomycin and Kanamycin) were used for antibiotic susceptibility test, among Ampicillin showed 70% resistant proved against to the strains of S.mutans. The plasmid of the isolates has specifi c antibiotic resistance against antibiotics like ampicillin and it has cell wall breaking capacity. R-plasmid (Resistant plasmid) was obtained from Ampicillin resistant strains of S. mutans from extracted tooth samples of dental caries disease. The molecular weight of the isolates were (KK2, 3 and KK4, 5) 800bp and 700bp respectively.