Author/Authors :
AKCA, Gülçin Gazi Üniversitesi - Diş Hekimliği Fakültesi - Temel Tıp Bilimleri Anabilim Dalı, Turkey , KAYAOĞLU, Güven Gazi Üniversitesi - Diş Hekimliği Fakültesi - Restoratif Diş Tedavisi ve Endodonti Anabilim Dalı, Turkey , AKCA, Ahmet Eralp GATA Diş Hekimliği Bilimleri Merkezi - Periodontoloji Anabilim Dalı, Turkey , SULTAN, Nedim Gazi Üniversitesi - Tıp Fakültesi - Tıbbi Mikrobiyoloji Anabilim Dalı, Turkey
Abstract :
Objective: To investigate the susceptibility to common (penicillin, ampicillin, ampicillin/sulbactam, amoxicillin/clavulanate, eritromycin, tetracycline, cefaclor, clindamycin) and new antibiotics (linezolid, quinupristin/dalfopristin) of viridans streptococci isolated from carious lesions. Material and Method: Samples taken from dentin caries were maintained in RTF solution, cultured on agar plates and pure colonies were isolated. Through conventional and biochemical methods 62 strains that belonged to viridans group streptococcus were identified: S. anginosus (2), S. constellatus (3), S. intermedius (3), S. mutans (12), S. sobrinus (7), S. mitis (15), S. oralis (5), S. sanguinis (6) and S. salivarius (9). Pure cultures were seeded onto agar plates, and using Kirby-Bauer disc diffusion method inhibition zones around antibiotic discs were evaluated. Results: All strains were susceptible to amoxicillin/clavulanate, ampicillin/sulbactam, linezolid and quinupristin/dalfopristin. Resistance frequency among all tested strains were: penicillin: 27 %, ampicillin: 27 %, tetracycline: 39 %, eritromycin: 21 %, cefaclor: 19 % and clindamycin: 24 %. S. mitis was the species most-associated with resistance. Multiple antibiotic resistance was found for S. intermedius, S. mitis, S. oralis, S. sanguinis and S. salivarius. Multiple resistance to penicillin-ampicillin-cefaclor was common. Conclusion: Reduced susceptibility to commonly used antibiotics is striking. β-lactamase-containing antibiotics amoxicillin/clavulanate and ampicillin/ sulbactam, and new-generation antibiotics linezolid and quinupristin/dalfopristin are reliable antimicrobials against viridans streptococci.
