Antibiotic Sensitivity Tests: A Rapid Method Suitable for Multiple Cultures

Light-scattering methods for antibiotic sensitivity tests.

The total intensity of light scattered in the angular range 30 degrees-130 degrees by a suspension of bacteria can be used as the basis of a method of antibiotic sensitivity testing. A procedure is given in which the bacteria are incubated in the presence of antibiotic, as a test, and in its absence, as a control, for 60 minutes. An incubation time of 90 minutes gives slightly more reliable res...

Antibiotic and Sulfonamide Disc Sensitivity Tests

Avian strains of Escherichia coli (213) were subjected to in vitro antibiotic sensitivity tests with twenty-four different chemotherapeutic agents. Chlorhexidine, polymyxin B, colistin, and nitrofurazone exhibited the greatest inhibitory activities against these strains. Various potencies of antibiotics were compared. The activity of sulfachloropyridazine on various types of media failed to sho...

Colouring agents for use in disc-antibiotic sensitivity tests.

A rapid method for phase recovery in Salmonella cultures.

Many methods have been proposed for the isolation of temporarily suppressed phases of diphasic Salmonella (Craigie, 1931; Gard, 1938; Hajna, 1944). These absorption methods are effective but require incubation for at least two days and considerable manual labor. Juenker (1946) suggested a procedure by which broth was inoculated with the organisms of the desired phase by passing them through a s...

A new rapid method for automatic complement-fixation tests.

Several automatic methods have been described for complement-fixation tests. However, each of these methods presents some inconvenience either due to cross contamination or to limited sensitivity. The new method consists basically in separating clearly the fixation stage from the haemolytic stage by using two different sampler plates placed on the same sampler. By this procedure, it becomes pos...