BETA-HEMOLYTIC STREPTOCOCCI IN ADVANCED PERIODONTITIS

The distribution of serotypes of beta-hemolytic streptococci was exami ned in 718 periodontitis patients. Subgingival samples were obtained w ith paper points from the 3 deepest lesions in each patient, transport ed in VMGA III, plated onto brucella agar with 5% sheep blood and incu bated anaerobically for 7 days. Serotyping and speciation were perform ed with Meritec(TM)-Strep Beta-Hemolytic Streptococcus Grouping Set an d the Analytab 20S(TM) Streptococcus System. Beta-hemolytic streptococ ci were recovered from 33.7% of patients and averaged 10.5% of the tot al viable counts in culture-positive subjects. The organisms occurred with higher prevalence in patients 35 years or older than in younger p atients. The predominant serotypes were F (62.9%), non-typeable (18.1% ), B (6.9%), C (6.9%) and G (5.2%). 100% of beta-hemolytic streptococc i were sensitive to penicillin, but less than 5% were sensitive to tet racycline, metronidazole or ciprofloxacin. Beta-hemolytic streptococci may contribute to inflammatory periodontal disease and may interfere with healing after therapy.