Susceptibility pattern of streptococcal isolates from oral cavity against commonly used antibiotics

ABSTRACT

To assess the susceptibility pattern of streptococcal isolates from oral cavity against commonly used antibiotics. Oral samples, including subgingival swabs, were collected from 120 patients aged 12 to 60 years. Two swabs were collected; first for rapid-strep testing for the presumptive diagnosis of Group A Streptococcal infection and second to culture for definitive bacterial identification. Antibiotic sensitivity of the isolated strains of streptococcus was done by direct disk diffusion method. Four different classes of antibiotics; Penicillin, Cephalosporin, Macrolide, and Vancomycin were tested to determine the sensitivity pattern. Out of 100 isolates recovered, the prevalence of streptococcal species was74%. The greatest zone of inhibition was achieved with amoxicillin, amoxicillin-clavulanic acid, and vancomycin [16, 17, and 18 mm respectively]. Zones of inhibition measured for cephalosporins and macrolides were less than the other groups [10.5 and 11 mm respectively]. Amoxicillin is still the drug of choice for prophylactic and therapeutic use in our dental settings not only for its better coverage on the streptococcus species but also due to its easy availability and affordability. This corresponds with the international literature, however, the importance of obtaining specimens for culture and sensitivity should be observed as a standard procedure, to minimize the chances of development of resistance and identify the changing trends of the infectivity mode