In vitro susceptibilities of bacterial isolates from conjunctival flora to gatifloxacin, levofloxacin, tosufloxacin, and moxifloxacin.
OBJECTIVE
To evaluate and compare the in vitro susceptibilities of various fluoroquinolones (i.e., gatifloxacin, levofloxacin, tosufloxacin, and moxifloxacin) against conjunctival bacterial flora.


METHODS
Two hundred sixty-six bacterial isolates were collected from the conjunctival sacs of 251 eyes of 224 patients (118 females and 106 males) ranging in age from 6 to 91 years old, who were scheduled for intraocular surgery at National Tokyo Medical Center. The minimum inhibitory concentration (MIC) was determined by broth dilution testing.


RESULTS
Of 266 isolates, 258 (97.0%) strains were gram-positive bacteria and eight (3.0%) strains were gram-negative bacteria. The MIC90 values of gatifloxacin, levofloxacin, tosufloxacin, and moxifloxacin against alpha-hemolytic streptococci were 0.39 microg/mL, 1.56 microg/mL, 0.39 microg/mL, and 0.20 microg/mL, respectively. The MIC90 values of gatifloxacin, levofloxacin, tosufloxacin, and moxifloxacin against Staphylococcus aureus were 1.56 microg/mL, 3.13 microg/mL, 0.78 microg/mL, and 0.78 microg/mL, respectively. The MIC90 values of gatifloxacin, levofloxacin, tosufloxacin, and moxifloxacin against Staphylococcus epidermidis were 1.56 microg/mL, 3.13 microg/mL, 3.13 microg/mL, and 0.78 microg/mL, respectively.


CONCLUSIONS
Although the clinical usefulness and efficacy of newer fluoroquinolones remains to be defined by clinical outcomes, the current study provides data for predicting relative in vivo potency among the fluoroquinolones.
Yamada
Masakazu
M
Division for Vision Research, National Institute of Sensory Organs, National Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo 152-8902, Japan. yamadamasakazu@kankakuki.go.jp
Hatou
Shin
S
Yoshida
Junko
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001372:Aza Compounds / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D002648:Child; D003228:Conjunctiva / Q000382:microbiology*; D004352:Drug Resistance, Microbial; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology*; D000077734:Gatifloxacin; D006801:Humans; D064704:Levofloxacin; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D000077266:Moxifloxacin; D009287:Naphthyridines / Q000494:pharmacology; D015242:Ofloxacin / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology
D000890:Anti-Infective Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D009287:Naphthyridines; D011804:Quinolines; D064704:Levofloxacin; D015242:Ofloxacin; C055185:tosufloxacin; D000077734:Gatifloxacin; D000077266:Moxifloxacin