Objective: Group A, C and G beta- hemolytic streptococci (BHS) are bacterial agents of tonsillopharyngitis, and cause various diseases and increase morbidity and mortality. In this study, we aimed to determine the percentage of group distribution and the rate of antibiotic resistance of BHS identified from the throat cultures of patients with acute tonsillopharyngitis.

Method: The throat swabs were collected from 200 patients with tonsillopharyngitis aged 1-80 years between October 2017 and May 2018. Bacterial isolates were identified by conventional methods such as Gram staining, bacitracin-trimethoprim sulfamethoxazole, catalase, and L-pyrrolidonyl β-naphthylamide. Latex agglutination test was used for serogrouping BHS. The antibiotic susceptibility profiles of BHS were determined by Kirby Bauer disc diffusion method. Streptococcus pyogenes ATCC 19615 strain was used as a control. Inhibition zone diameters were evaluated according to the Clinical Laboratory Standards Institute (CLSI) criteria.

Results: Thirty-four (17%) BHS were isolated from 200 throat swap specimens.Distribution percentages of BHS group were determined as 44.1% (15) for A, 29.4% (10) C, 23.5% (8) G and 2.9% (1) F. All isolates were 100 % susceptible to penicillin, vancomycin and levofloxacin. The highest resistance (29.4%) was found against ampicillin followed by clindamycin (26.5%), erythromycin (23.5%), amoxycillin-clavulanic acid and tetracycline (14.7%), cefotaxime and ceftriaxone (11.8%), clarithromycin (8.8%) and chloramphenicol (2.9%).

Conclusion: This study revealed that Group C, and Group G Streptococci had lower resistance to some antibiotics than Group A Streptococci. Based on the findings, the BHS group distributions and antibiotic resistance profiles should be repeated at certain intervals and precautions should be taken with public health surveillance studies.