白内障手術の周術期における結膜囊内常在菌叢―フルオロキノロン点眼薬による減菌化と感受性変化

Bacterial flora in the conjunctival sac before and after cataract surgery. Changes in population and drug sensitivity by topical fluoroquinolones

要約　目的：白内障手術前後のフルオロキノロン系抗菌薬の継続点眼による結膜囊内細菌の数と感受性の変化の検討。方法：白内障手術を受けた92例152眼を対象とした。79眼には0.3％ガチフロキサシン点眼薬，73眼には0.5％レボフロキサシン点眼薬を手術の7日前から1日4回点眼し，術後は1日3回点眼した。点眼開始前と手術14日後に下眼瞼結膜囊からの擦過物を培養し，細菌を検査した。結果：点眼前の菌検出率はガチフロキサシン群では89.9％，レボフロキサシン群では82.2％であり，術後はそれぞれ32.9％と31.5％で，両群とも点眼により有意に減少した。レボフロキサシン群では点眼後にガチフロキサシンとレボフロキサシン耐性株が増加し，感受株が減少したが，ガチフロキサシン群では変化がなかった。結論：抗菌薬の継続点眼で菌検出率が減少した。ガチフロキサシンでは耐性誘導が起こりにくかった。

Abstract.　Purpose：To report changes of bacterial flora and drug sensitivity in the conjunctival sac after instillation of fluoroquinolone before and after cataract surgery. Cases and Method：This study was made on 152 eyes of 92 patients who underwent cataract surgery. Seventy-nine eyes received 0.3％ gatifloxacin and 73 eyes received 0.5％ levofloxacin 4 times daily for 7 days before surgery. Instillation was continued 3 times daily after surgery. Scrapings from conjunctival were cultured and examined before instillation and 14 days after surgery. Results：Before instillation,bacterial organisms were detected in 89.9％ of eyes receiving gatifloxacin and in 82.2％ of eyes receiving levofloxacin. After instillation,they decreased,significantly,to 32.9％ and 31.5％ of eyes respectively. Instillation of levofloxacin was followed by increase in strains resistant to gatifloxacin and levofloxacin. No such change was observed after instillation of gatifloxacin. Conclusion：Instillation of gatifloxacin or levofloxacin was followed by decrease of bacterial flora. Gatifloxacin did not induce drug-resistance.