Comparative in vitro activities of new fluorinated quinolones and other antibiotics against coagulase-negative Staphylococcus blood isolates from neutropenic patients, and relationship between susceptibility and slime production.
We evaluated the in vitro antibiotic susceptibilities of 31 coagulase-negative Staphylococcus isolates causing septicemia in neutropenic patients undergoing norfloxacin prophylaxis. All the strains but one were resistant to 1 microgram of norfloxacin per ml. At the same concentration, ciprofloxacin, ofloxacin, imipenem, and pefloxacin were inhibitory for 19 (61%), 19 (61%), 18 (58%), and 14 (45%) of the evaluated strains, respectively. Imipenem had an MBC/MIC ratio of greater than or equal to 32 against 19 (61%) of the evaluated isolates, and resistant subpopulations were detected at 5 micrograms/ml in 16 of 17 oxacillin-resistant strains and in 3 of 14 oxacillin-susceptible or -tolerant strains. Resistance to gentamicin was seen with increased frequency among slime-producing strains.
Venditti
M
M
Cattedra di Patologia Medica III, Università di Roma, Italy.
Santini
C
C
Serra
P
P
Micozzi
A
A
Gentile
G
G
Martino
P
P
D042462:4-Quinolones; D000380:Agranulocytosis / Q000382:microbiology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology*; D003030:Coagulase / Q000378:metabolism; D004352:Drug Resistance, Microbial; D006801:Humans; D008826:Microbial Sensitivity Tests; D009503:Neutropenia / Q000382:microbiology*; D018805:Sepsis / Q000188:drug therapy / Q000382:microbiology; D013210:Staphylococcus / Q000187:drug effects* / Q000201:enzymology
D042462:4-Quinolones; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D003030:Coagulase