Hospital personnel with penicillin-resistantStreptococcus viridans. A case for special consideration in the prevention of bacterial endocarditis

Penicillin is the drug of choice for the prevention of bacterial endocarditis (BE) resulting from dental treatment. The susceptibility ofStreptococcus viridans to this antimicrobial agent was studied. A representative sample of hospital personnel (N = 76) was compared to a control group of seventy-six subjects who were not associated with the hospital. Twenty-four of the hospital personnel worked in wards that consume 0.13 to 1.64 (mean ± SD = 0.88 ± 0.64) gm penicillin per day per position (low consumption group = LCG) and fifty-two worked in wards that consume 2.27 to 3.67 (mean ± SD = 3.04 ± 0.55) gm penicillin per day per position (high consumption group = HCG). Antibiograms of oral isolates showed that, while 48.08% of the subjects from the HCG revealed penicillin-resistantS. viridans only 8.33% of the subjects from the LCG and 7.89% of the control group presented such results. The data presented suggest that there are subjects who may unknowingly carry penicillin-resistantS. viridans as part of their oral flora. It is therefore recommended that the preferable antibiotic used for the prevention of BE should be determined by an antibiogram.