急性単純性尿路感染症の菌交代実験

Abstract

菌交代を起こすようにラットの膀胱内接種弱毒菌E. faecalis, P. aeruginosaに対する抗生物質他の影響をみた。E. faecalis(1×108CFU/ml)と希釈P. aeruginosa(1×105CFU/ml)混合膀胱内注入では, E. faecalisの方が1000倍以上あったのは酢酸膀胱内注入群で2日後に5/13匹で, 6日後2匹に菌交代が起きた。一般のminor floraに関しては少数菌は実際には少なく, 抗生物質を投与しなくても自然に消失して行くことが多い。ABPC 4mg 1回/1日6日間の投与では膀胱内酢酸注入群では1/3匹に菌交代現象が起きたのみであった。コルチゾン処置群で3/5匹に交代現象が起きたが, MMC腹腔内接種群では5匹とも菌交代は起こらなかった。無処置のラットでも3/12匹に菌交代が起き, その他9/13匹にはP. aeruginosaが消失した。菌交代はかならずしも抗生物質に依存しなかった

Experimental acute simple urinary tract infections were induced in female rats to determine whether low-virulent bacteria can reside in the simple urinary tract, whether minor flora can co-exist with major flora, and whether the bacterial population changes when antibiotics, to which major flora is sensitive and minor flora is resistant, is administered. "Enterococcus faecalis (E. faecalis) and Pseudomonas aeruginosa (P. aeruginosa) were instilled into the bladder transurethrally. Most rats had more than 1 x 10(4) CFU/ml of E. faecalis and P. aeruginosa two and four days after inoculation. Rats were divided into three groups. Mitomycin C injection group, acetic acid bladder instillation group, hydrocortisone injection group. E. faecalis (1 x 10(7) CFS/ml) and P. aeruginosa (1 x 10(4) CFS/ml) were instilled into the bladder. Bacterial count of E. faecalis was over 1, 000 times that of P. aeruginosa in 14 rats two days after inoculation and in two rats six days after inoculation. Ampicillin (ABPC) was administered once a day for four days from two to five days after inoculation under the same condition. Bacterial count of E. faecalis was over 1, 000 times that of P. aeruginosa in 26 rats two days after inoculation. The bacterial population changed in seven of the 26 rats after administration of ABPC, and in three of the 12 untreated rats.