Abstract
A new method of the microbiological determination of galactose and lactose in the urine of newborn babies was projected by the use of galactose-se. var, and lactose-se. var., the Mutabile-type Var. Murase of enteric bacteria. Galactose or lactose itself was believed to be contained in the baby urine as the normal composition.
For the determination of galactose, the urine was used directly.
In the case of lactose, the urine was used after treating with Salm. typhi-murium for one night to ferment and to exclude galactose.
Seedlayer of each galactose-se. and lactose-se. var. as well as the cups were prepared for determination. The urine was diluted in two-fold with distilled water. Each dilution was dispensed into a cup in a dose of 0.1 ml and incubated for one night. Diameter of the growth inhibition zone around the cup was measured by vernier on the following day.
Concentration of galactose or lactose was calculated from the endpoint titre, by comparing with that of known controls.
Influence upon the titre which might be derived directly from the urine was negligible.
This procedure is very simple to run and does not require any special reagents or instruments. Sensitivity of the galactose-se. var. or lactose-se. var. was tested occasionally and the strains of constant sensitivity were used. The test can be completed ordinarily within 24 hours from the start. Two mcg of galactose and 16 mcg of lactose in 0.1 ml of the urine seem to be the minimum detectable concentration.
The sensitivity of the detection of lactose can be enhanced up to 2 mcg in 0.1 ml by the so-called medium apply method of Fukutome et al.
From the above experiments, it was found that in most cases the concentration of galactose in the urine lies between 40 mcg/m1-160 mcg/ml and lactose between 160 mcg/ml-3 20 mcg/ml. Galactose was positive in 51 of 52 cases and lactose in 52 of 52 cases. Therefore, these dose seemed to show the physiologic concentrations in the urine of newborn babies in Japan.
In the authors experiments, urinary samples were collected only once per baby, but the percentage of sugar positive cases was much higher than that of European works performed by paperchromatographic technic.
