Occurrence of Antibiotic-Resistant Viridans Streptococci in Healthy Versus Disabled Children

Objective: To compare the antibiotic susceptibility profiles of Viridans streptococci (VS) isolated from the oral cavity of normal and disabled children in Kuwait. Methods: Plaque samples were collected, from 51 normal and 51 disabled children, from the tooth and tongue surfaces and cultured on appropriate media for the isolation of VS. Representative colonies were identified to species level using API 20S test kits. The antibiotic susceptibility testing was performed by determining the MICs of 7 antibiotics (amoxicillin, cephalothin, clindamycin, erythromycin, penicillin G, tetracycline and vancomycin) using E-test strips. Results were interpreted according to NCCLS interpretive criteria and subjected to SPSS statistical analysis for comparison. Result: A total of 270 and 307 VS were isolated from the normal and disabled children respectively. The percentage of resistant VS isolated from the disabled children ranged from 23% for tetracycline to 62.1% for erythromycin and for normal children, 11% for clindamycin to 42% for amoxicillin. A significant difference was noted in the percentage of antibiotic-resistant VS from disabled versus normal children against penicillin G (46.9% vs 19%; P < 0.0001); clindamycin (45.9% vs 11%; P < 0.0001); tetracycline (33.2% vs 23.7%; P < 0.0001) and erythromycin (62.1% vs 38.1%; P < 0.035). There was however no significant difference with amoxicillin (P > 0.388), cephalothin (P > 0.652) and vancomycin (P > 0.187). Conclusion: The data showed that there is a difference in the level of resistance of oral VS isolated from healthy and disabled children to some commonly used antibiotics in dentistry.

Supported by Kuwait University Grant# DP01/01