IADR Abstract Archives
Antimicrobial Susceptibility Profile of a Cariogenic Bacteria
Objectives: To evaluate the susceptibility of Streptococcus mutans (Sm) ATCC 25175 strains against different antimicrobial agents for systemic use in vitro.
Methods: Sm ATCC 25175 strains were grown. Kirby-Bauer disc diffusion technique was used to determine the susceptibility of Sm against different antibiotics established by The Clinical & Laboratory Standards Institute: Erythromycin 15 ug (E), Clarithromycin 15 ug (CLR) Tetracycline 30 ug (TE), Vancomycin 30 ug (VA), Ceftriaxone 30 ug (CRO). 2% Chlorhexidine (CHX2) was used as a negative control. Sm were grown on Muller Hinton agar supplemented with 5% sheep blood, adjusted to the Mc Farland 0.5 turbidity scale, then measured the optical density in a spectrophotometer. The antibiogram was incubated in anaerobiosis at 37 ° C for 48 h, then the inhibition halos were measured with a Vernier digital caliper. The experiment was repeated 4 times.
Results: The average measures of inhibition halos produced by each antibiotic were: E (45.7 mm), CLR (39.2 mm) TE (37.1 mm), VA (30.2 mm), CRO (42 mm), CHX 2% (22mm).
Conclusions: Sm ATCC strains were highly sensitive to all the antimicrobials studied. A larger zone of inhibition was observed with E followed by CRO compared to CHX 2% which is an antimicrobial used in dentistry and showed smaller zones of inhibition against Sm.
Methods: Sm ATCC 25175 strains were grown. Kirby-Bauer disc diffusion technique was used to determine the susceptibility of Sm against different antibiotics established by The Clinical & Laboratory Standards Institute: Erythromycin 15 ug (E), Clarithromycin 15 ug (CLR) Tetracycline 30 ug (TE), Vancomycin 30 ug (VA), Ceftriaxone 30 ug (CRO). 2% Chlorhexidine (CHX2) was used as a negative control. Sm were grown on Muller Hinton agar supplemented with 5% sheep blood, adjusted to the Mc Farland 0.5 turbidity scale, then measured the optical density in a spectrophotometer. The antibiogram was incubated in anaerobiosis at 37 ° C for 48 h, then the inhibition halos were measured with a Vernier digital caliper. The experiment was repeated 4 times.
Results: The average measures of inhibition halos produced by each antibiotic were: E (45.7 mm), CLR (39.2 mm) TE (37.1 mm), VA (30.2 mm), CRO (42 mm), CHX 2% (22mm).
Conclusions: Sm ATCC strains were highly sensitive to all the antimicrobials studied. A larger zone of inhibition was observed with E followed by CRO compared to CHX 2% which is an antimicrobial used in dentistry and showed smaller zones of inhibition against Sm.
