L Type of Growth in Gonococcus Cultures. ∗ †

Abstract

It was described in a former note that in cultures of various Gram negative bacteria tiny secondary colonies similar in many respects to the LI colonies of Streptobacillus moniliformis develop. 1 The appearance of these colonies is always preceded by the transformation of the bacteria into large swollen forms. More recently it has been observed that the secondary colonies develop from these large forms. 2

A similar course of events was observed in gonococcus cultures. In certain cultures the cocci before disintegrating swell up into large deeply stained spherical bodies similar in every respect to the large bodies of Gram negative bacteria. If such cultures are kept one or two days at a temperature between 25 to 30° C., one notes below the colonies in the agar a slight secondary growth very similar to the L type of growth observed in colon bacillus and influenza colonies. It consists of small granules and fine filaments which usually degenerate in 24 hours. In gonococcus cultures this peculiar secondary growth does not develop as abundantly nor as distinctly as in the cultures of Gram negative bacteria, and without the experience obtained with the latter it would probably have been overlooked. The main evidence in support of the supposition that this slight transient growth corresponds to the development of the L type colonies is the essential similarity of the whole process in different bacterial cultures.

The observation of this process in gonococcus cultures possess some importance inasmuch as it is the first example of the occurrence of this process in a species of bacteria besides the Gram negative bacilli. Attempts to demonstrate a similar secondary growth in the colonies of Gram positive cocci, especially in the colonies of streptococci, have been unsuccessful thus far.