[The effectiveness of the new fluoroquinolones against the normal bacterial flora of the conjunctiva].
BACKGROUND
Our aim was to determine the antibiotic susceptibility of the preoperative conjunctival bacterial flora against 25 commonly used antibiotics, especially the new fluoroquinolones levofloxacin, gatifloxacin, and moxifloxacin.


METHODS
The Kirby-Bauer disk-diffusion technique was used to test for the in vitro antibiotic susceptibility of conjunctival bacterial strains isolated from 160 patients (median=74 years, mean=71 years) undergoing cataract surgery at the Department of Ophthalmology, Stanford University, CA, USA.


RESULTS
Among the 256 bacteria isolated, 201 (79%) were coagulase-negative staphylococci (CNS), 26 Staphylococcus aureus, 15 Streptococcus group D and 14 gram-negative rods. A total of 100 of these 256 strains (39%) were classified as multiresitant (resistant to>or=five antibiotics). The resistance rate (RR) of commonly used antibiotics for all CNS was: gatifloxacin=moxifloxacin<gentamycin=tobramycin=levofloxacin=neomycin<ciprofloxacin=ofloxacin<erythromycin. The RR for S. aureus and the gram-negative rods was low and insignificant in comparison to the other antibiotics tested. None of the Streptococcus group D were resistant to gatifloxacin, levofloxacin, or moxifloxacin, however, they were highly resistant (RR over 30%) to the other antibiotics. Some 50% of the bacteria were resistant to erythromycin.


CONCLUSIONS
Newer generation fluoroquinolones provide excellent efficacy against coagulase-negative staphylococci and Streptococcus group D despite a high number of multiresitant bacteria.
Koss
M J
MJ
Universitätsaugenklinik der Ludwig-Maximilians-Universität München, Germany. Michael.Koss@kgu.de
Eder
M
M
Blumenkranz
M S
MS
Klauss
V
V
Ta
C N
CN
de Kaspar
H M
HM
D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D002470:Cell Survival / Q000187:drug effects; D003228:Conjunctiva / Q000187:drug effects* / Q000382:microbiology*; D003234:Conjunctivitis, Bacterial / Q000188:drug therapy* / Q000382:microbiology*; D005260:Female; D024841:Fluoroquinolones / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D013210:Staphylococcus / Q000166:cytology / Q000187:drug effects*; D013291:Streptococcus / Q000166:cytology / Q000187:drug effects*
D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones