To determine the changes found in antimicrobial resistant character occurred among viridans groups of streptococci, this study examined 30 viridans group streptococci isolated from infective endocarditis patients. The isolation pattern revealed based on biochemical identification as four viridans streptococcal species groups–mitis, mutans, salivarius and sanguinis. Resistance rates of the isolates were as follows, Penicillin–2; Clindamycin–2; Erythromycin–5; Azithromycin–10; Vancomycin–4; Levofloxacin–1 and Ciprofloxacin–2.
