E. Kihlstrom et B. Normann, OCCURRENCE OF PNEUMOCOCCI WITH RESISTANCE OR DECREASED SUSCEPTIBILITYTO PENICILLIN IN SOUTHEAST SWEDEN, Scandinavian journal of infectious diseases, 27(5), 1995, pp. 489-494
The minimal inhibitory concentrations (MICs) of 14 beta-lactam and non
-beta-lactam antibiotics were determined for all pneumococci with inte
rmediate susceptibility (I), (n = 26) or resistance (R), (n = 15) to p
enicillin G isolated at the Clinical Microbiology Laboratory, Universi
ty Hospital, Linkoping, Sweden during 1994. These isolates accounted f
or 3% of ail pneumococcal isolates. The results were compared with tho
se of 26 penicillin-susceptible isolates. The MICs of all tested beta-
lactam antibiotics increased with MICs of penicillin G. The least incr
ease and the lowest MICs of these agents were recorded for cefotaxime
and imipenem. 27% of I- and R-strains were multiple-resistant, most of
ten to tetracycline, trimethoprim-sulfametoxazole, erythromycin, chlor
amphenicol and clindamycin. All strains were susceptible to vancomycin
and rifampicin. I-strains belonged to at least 5 different serotypes.
However, 12 of the 15 R-strains were serotype 9 and 6 of these were r
ecovered during contact tracing, indicating spread of a single clone w
ithin day-care centres.