IN-VITRO BRODIMOPRIM ACTIVITY ON BACTERIAL STRAINS

The antibacterial activity of brodimoprim (BDP) was compared to that o f trimethoprim (TMP) and to 4 other antibiotics (3 beta-lactams and on e macrolide). The 237 tested strains were selected predominantly among bacteria isolated from respiratory tract infections: 133 Gram-negativ e bacilli and 98 Gram positive cocci. The study included: determinatio n of minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of all antibiotics of the study for all isolate s; kinetics of bactericidal activities for selected susceptible strain s; correlation between MICs and inhibition zones (standard agar diffus ion technique) of BDP (regression line). The results of the study show ed: [1] no significant difference between in vitro activities of BDP a nd TMP against all tested strains; [2] low MICs of both drugs for Haem ophilus influenzae, Legionella pneumophila, Staphylococcus aureus (met hi-S and methi-R), Streptococcus pneumoniae (peni-S), streptococci and enterococci; [3] kinetics of bactericidal activities indicating 4 log decrease of inoculum size with BDP for Staph. aureus, S. pneumoniae, H. influenzae, within 7 hours; [4] correlation was established between inhibition zones and MICs of BDP, with a coefficient of correlation r = 0.88 for 182 strains. In conclusion, BDP exhibited in vitro antibac terial and bactericidal activities at least equal to that of reference drugs against most respiratory pathogens; BDP was superior to compara tors against methi-R staphylococci and enterococci.