Antibiotic resistance rates and macrolide resistance phenotypes of viridans group streptococci from the oropharynx of healthy Greek children

A total of 200 isolates of viridans group streptococci isolated from the or opharynx of healthy Greek children were studied. Vancomycin, rifampicin, fl uoroquinolones and dalfopristin/quinupristin were active against all tested isolates. High level resistance to gentamicin was not seen. Intermediate a nd high-level penicillin resistance was present in 28.5 and 14.5% isolates, respectively. with 41.3% of the latter group, being also resistant to cefo taxime. Resistance rates to other antimicrobials were as follows - erythrom ycin 38.5%, clarithromycin 33.5%, clindamycin 7.5% and tetracycline 23%. Pe nicillin resistance occurred more frequently in Streptococcus mitis isolate s, while macrolide resistance was more frequent in S. oralis. MLSB resistan ce phenotype M was dominant (74%) among erythromycin resistant isolates, wi th phenotypes IR and CR being represented by 6 and 20% of isolates, respect ively. (C) 2001 Elsevier Science B.V. and International Society of Chemothe rapy All rights reserved.