Bacteriological study on the prevalence and antibiotic susceptibility of Streptococcus mutans isolated from saliva of patients with different dental status

Abstract

Abstract:

    _{Streptococcus mutans believed to be the main cause of tooth decay in humans, has developed multiple mechanisms for colonizing the tooth surface and has become an important type of caries-causing biofilm; therefore, it is more resistant to antimicrobial agents. The study aimed to cultivation with detection of “streptococcus mutans” from oral cavity of study population with different dental statuses. It was collected 300 saliva samples by cotton swab from patients attending to different dental clinics. The samples cultured on selective media Mtanus Sangius Agar (MSA)and Mitis Salivarius Bacitracin Agar (MSBA). The isolates identified by morphological and biochemical tests, API 20 strep, VITK system and confirm by PCR (16SrRNA), the results of culture and diagnosis appeared that Streptococcus mutans recorded 36(12%) isolates from 300 samples. The results appeared that all isolates (36) were resistance to beta lactam antibiotics that used in this study (Penicillin, Ampicillin, Cefepime, Cefotaxime,) and 94.4% of isolates were resistance to Clindamycin. In contract, Levofloxacin was more effective antibiotic against these isolates, it registered 100% of sensitivity. This study concluded that the S. mutans possessed total resistance to β-lactam antibiotics and high to resistance to Clindamycin. While Levofloxacin was the most effective antibiotic against this bacterium. We recommended against the indiscriminate use of antibiotics and suggests further research on S. mutans using molecular method to detect antibiotic resistance genes in these bacteria}