産業医科大学における空調冷却塔(Cooling Tower)からのLegionella Pneumophilaの分離  [in Japanese] Isolation of Legionella pneumophila from the UOEH Cooling Tower  [in Japanese]

ヒトの肺炎の原因菌の一種であるLegionella Pneumophilaは, 空調冷却塔(cooling tower)の水に生息することが知られている. 我々は昭和61年7月, 本学の冷却塔の水よりLegionelia属菌の分離を試みた. 12基より冷却水を採取し酸処理後, Legionelia属菌の選択培地であるWadowsky-Yee-Okuda(WYO)培地に塗布した結果3基より1,000-2,000 colony forming unit(CFU)/lのL.pneumoPhilaを検出した. 本邦における従来の報告と比較して, 冷却塔からの検出率は低かったが次亜塩素酸ナトリウムによる消毒中のcooling towerからも検出されている点が今後の問題点と考える.(1986年8月15日 受付)

Twelve samples of water taken from the cooling tower of UOEH were examined for the presence of microorganisms belonging to the genus Legionella by using a new selective medium, Wadowsky-Yee-Okuda (WYO) medium. Three samples contained this organism and they were identified as Legionella pneumophila from their biochemical properties. Among the three contaminated samples, two yielded L pneumophila serogroup I and 3, and the other contained only L. pneulnophila serogroup 1. One of the samples of the contaminated cooling tower water was treated with sodium hypochlorite as a disinfectant, indicating that this agent is probably not effective in eliminating L pneumophila from cooling tower water at that concentration. An effective method of disinfection for Legionella spp, in the cooling tower must be developed to prevent infection in the hospital