title: In vitro antimicrobial activity of gatifloxacin compared with other quinolones against clinical isolates from cancer patients.
abstract: Owing to the predominance of gram-positive pathogens in neutropenic cancer patients, newer generation quinolones with an expanded gram-positive spectrum and enhanced potency, may have a role to play for prophylaxis and/or empiric therapy in such patients. The in vitro activity of gatifloxacin was compared with that of ciprofloxacin, levofloxacin and trovafloxacin against 848 recent clinical isolates from cancer patients. Against gram-positive organisms, gatifloxacin was the most active agent tested inhibiting all Aerococcus, Listeria monocytogens, Micrococcus, Stomatococcus mucilaginous, Bacillus, and Rhodococcus equi strains at < or =2 mg/l, its designated susceptibility breakpoint. It was also very active against methicillin-susceptible staphylococci and Streptococcus spp. (including penicillin nonsusceptible Streptococcus pneumoniae and viridans streptococci). It had moderate activity against methicillin-resistant staphylococci and Enterococcus faecalis, inhibiting 68-80% of these strains at < or =2 mg/l. Gatifloxacin also had good activity against the Enterobacteriaceae (although ciprofloxacin was more potent) inhibiting >95% of isolates at < or =1 mg/l. Nonfermentative gram-negative organisms were less susceptible to all 4 agents. Gatifloxacin was very active against Acinetobacter lwoffi (MIC100 0.12 mg/l) and had moderate activity against Acinetobacter baumanii, Chryseobacterium spp., Stenotrophomonas maltophilia, Pseudomonas aeruginosa and other Pseudomonas species. Alcaligenes xylosoxidans strains were relatively resistant to all 4 agents.
authors.affiliation: Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas, M.D. Anderson Cancer Center, Houston, TX 77030, USA. krolston@mail.mdanderson.org
authors.forename: Kenneth V I
authors.initials: KV
authors.lastname: Rolston
authors.forename: Irfan
authors.initials: I
authors.lastname: Vaziri
authors.forename: Susan
authors.initials: S
authors.lastname: Frisbee-Hume
authors.forename: Harriet
authors.initials: H
authors.lastname: Streeter
authors.forename: Barbara
authors.initials: B
authors.lastname: LeBlanc
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000145:classification / Q000627:therapeutic use*; D016983:Enterococcus / Q000187:drug effects; D005285:Fermentation; D024841:Fluoroquinolones / Q000494:pharmacology / Q000627:therapeutic use*; D005500:Follow-Up Studies; D000077734:Gatifloxacin; D006088:Gram-Negative Aerobic Bacteria / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D009369:Neoplasms / Q000150:complications / Q000188:drug therapy / Q000382:microbiology; D009503:Neutropenia / Q000150:complications / Q000188:drug therapy / Q000382:microbiology; D015363:Quinolones / Q000737:chemistry / Q000145:classification* / Q000627:therapeutic use*; D013210:Staphylococcus / Q000187:drug effects; D013291:Streptococcus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D015363:Quinolones; D000077734:Gatifloxacin