Antibiotic resistance and penicillin tolerance in clinical isolates of group B streptococci.
The aim of this study was to determine the susceptibility patterns of 100 group B streptococcal strains isolated in our hospital and to ascertain tolerance to penicillin by determining quantitative killing curves. We found two strains with intermediate susceptibility to penicillin and eight strains to ampicillin. Seventeen isolates were tolerant to penicillin, with bacterial counts decreasing 2 to 3 log during the first 8 h but still above 10(2) CFU/ml after 24 h. The kinetic study shows that penicillin tolerance is not rare among group B streptococci isolated in our hospital.
Betriu
C
C
Servicio de Microbiología Clínica, Hospital Universitario San Carlos, Madrid, Spain.
Gomez
M
M
Sanchez
A
A
Cruceyra
A
A
Romero
J
J
Picazo
J J
JJ
D000668:Ampicillin Resistance; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D018432:Drug Resistance, Multiple; D004361:Drug Tolerance; D006801:Humans; D007700:Kinetics; D007769:Lactams; D008826:Microbial Sensitivity Tests; D010403:Penicillin Resistance; D010406:Penicillins / Q000494:pharmacology*; D013290:Streptococcal Infections / Q000188:drug therapy*; D013292:Streptococcus agalactiae / Q000187:drug effects*; D013997:Time Factors
D000900:Anti-Bacterial Agents; D007769:Lactams; D010406:Penicillins