Biological Study of Water from Air-Water Syringes II : Endotoxin concentration

Abstract

We previously reported a study on contaminated water from air-water syringe before treatment. The purpose of this study was to compare the number of bacteria and concentration of endotoxin in water before and after displacement. The number of bacteria was counted using Standard Method Agar (37°C, 48hours). The concentration of endotoxin was measured with ENDOSPECY. Gram stain and VITEK system were used for indentification of bacteria. The results were as follows : The results were as follows: (1) The number of bacteria between pre-and post-displacement of 250ml decreased 93% from 1.36×10^3〜217.0×10^3 to 0〜10.1×10^3CFU/ml. (2) The concentration of endotoxin between pre-and post-displacement of 250ml decreased 88% from 11.5〜472.8 to 0.8〜57.5ng/ml. (3) There was no significant relation between the number of bacteria and the concentration of endotoxin. (4) The decreasing rate of the bacterial counts and the concentration of endotoxin in direct water supply after 250ml displacement were about 10% higher than those in indirect water supply. (5) Bacteria such as Sphingomonas paucimobilis, Flavobacterium sp., Moraxella sp., Corynebacterium sp. were identified from the water samples.