Streptococcus bovis revisited: A clinical review of 81 bacteremic episodes paying special attention to emerging antibiotic resistance

Following 2 cases of Streptococcus bovis endocarditis with a high level of resistance to clindamycin during 2002, the authors reviewed their clinical experience with S. bovis bacteremia during 2 periods, starting in 1980. 81 episodes of S. bovis bacteremia represented approximately 1% of all episodes of bacteremia. In 32 (40%) cases the bacteremia represented endocarditis, in 15 (19%) the bacteremia originated from sick bowel, 11 (14%) were suspected to arise from urinary tract infection, 10 (12%) originated from biliary or peritoneal infection, and 13 from other or unknown sources. 25 (31%) of the bacteremias were polymicrobial. All of the isolates were highly susceptible to penicillin and clindamycin, with the following exceptions: 2 isolates had a minimal inhibitory concentration (MIC) of 0.5 mg/l to penicillin (in 1997) and 5 isolates had an MIC of > 2 mg/l to clindamycin (in 1997, 1998, 2000 and 2002). The 2 most recent of these 5 had high-level resistance to clindamycin of > 256 mg/l. It seems that clindamycin resistance in S. bovis is an emerging phenomenon, in contrast to penicillin resistance, high levels of which have not yet been described in S. bovis.