Meningitis caused by multiply antibiotic-resistant viridans streptococci.

Two patients are described with meningitis caused by multiply antibiotic-resistant strains of viridans streptococci; both isolates were resistant to penicillin (MIC greater than 3 micrograms/ml) (4.8 U/ml) and to several other antimicrobial agents. Our findings underscore the importance of doing in vitro sensitivity testing with clinical isolates of viridans streptococci to determine appropriate therapy for infected patients. Multiply antibiotic-resistant strains of viridans streptococci have also been recently isolated in the same populations in South Africa in which the prevalence of resistant Streptococcus pneumoniae is high. Therefore, isolation of resistant clinical strains of viridans streptococci may suggest the need for in vitro surveillance of emerging antibiotic resistance in both streptococcal species.