Antibiotic resistance study of invasive S.pneumoniae

121 invasive pneumococci isolated from meningitis, septicemia, pneumopathies and other clinical infections (osteo-arthritis, peritonitis, sinusitis, otilis, conjunctivitis, plagues) were screened for susceptibility to penicillin G (P), erythromycim (E), chloramphenicol (Cl), tetracycline (T), ceftriaxone (Cro), and sulfametoxazole trimethoprim (SxT) by diffusimetric method, by MICs to P and Cro by agar dilutions and E-test. 48.8% were penicillin resistant (MICs > 0.12 microgram/ml), 22.7% being highly resistant (MICs 3-8 micrograms/ml). Any strain was resistant to P only, but patterns with P included were frequent (55.8%). Resistance to SxT was highest (monoresistance 25.6% as well as polyresistance 69.8%). 72.9% were resistant strains to > or = 1 antibiotic with 12 patterns of resistance (1-5 antibiotics). All of the strains were susceptible to Cro (MICs-0.003-0.5 microgram/ml). Resistance was closely correlated to serotypes 6,9,14,19,23 to site of isolation and diagnosis. Pneumococci from meningitis were 2-3 times more susceptible to P,E,Cl,T and SxT than the isolates from pneumopathies or other infections.