Search

The test paper here described makes it relatively easy to choose the antibiotic best suited for treatment of a given bacterial infection. Each type of test paper bears both a culture medium and an antibiotic and is supplied, dry and sterile, in a transparent envelope. For a given test, the paper is wetted and inoculated and the envelope with its contents is incubated. It is not necessary to wait for the appearance of visible colonies because the metabolic activity of the bacteria is detected by an indicator (triphenyltetrazolium chloride) which is colorless until reduced to a bright red dye by bacterial enzymes. The reliability of the new test was established by a comparative study with other methods in 100 clinical cases. The test paper is easily stored, and the entire unit can be incinerated after use. It is therefore useful in general office practice and should help to make sure that each patient receives the most effective antibiotic.

A p H test paper (Hydrion) was found to have the most favorable color scale over a p H range from 1 to 6, in comparison with many available indicator papers. Its use gives good correlation with the standard titration technique. Availability of a reliable, easily used indicator paper would encourage the physician to use gastric analysis more frequently and would stimulate patients to accept self-testing just as diabetics test for glycosuria.