Degeneration and Variation of Gonococci

Abstract

Several gonococcus strains which were previously tested by comparative agglutination with type-specific immune-sera as to their serological types were cultivated on blood-water agar (Casper). Single colonies grown on this medium showed a formation of papillae after 5 days as well in freshly isolated strains as in gonococcus cultures cultivated over a period of several months. By transferring these colonies new papillae-bearing colonies were obtained. By transplantation of the papilla-free part of the colony, in a 5-day interval, cultures in completely papilla-free form could be cultivated. From those papilla-free and papillae-bearing forms of both, serologically different types of gonococci, immune sera were prepd. Sera prepd. with the papilla-free form showed overlapping valencies for the heterologous type according to the grade of degeneration. The papillae-bearing colony gave type-specific agglutination. A serological classification of gonococci based only on cultural behavior is not possible, as both of the serological different types could be transformed from papillae-bearing to papilla-free forms.[long dash]The difficulties arising in the classification of gonococci even from acute cases of gonorrhea caused by non-specific reactions with the specific immune-sera may originate in degeneration processes. Upon cultivation on artificial media even former type-specific test-strains undergo changes which induce the loss of their former type-specific characteristics. 2 test-strains, after prolonged cultivation on artificial media, gave not only overlapping serological reactions but were also agglutinated by normal serum and saline. Agglutinin-absorption tests revealed that sometimes degenerated strains are capable of absorbing the agglutinins from a type-specific serum, but that the agglutinins of a serum prepared with a degenerated strain are not absorbed by a freshly isolated strain. If in the transference of gonococci, even from acute gonorrhea, to artificial media such a rapid degeneration may occur that they may give not only nonspecific serological reactions but also may be agglutinated by normal serum or saline, strains isolated from chronic gonorrhea could not be expected to be a definite type. By adaptation to human tissues, the gonococcus undergoes the same degenerative process which we see after adaptation to artificial media. Test-strains of gonococci, classified by the comparative agglutination method as type-specific, are shown in another exp. to have mixed-phasic properties in the slide-agglutination test. By picking individual colonies, both mixed and specific phases of the same strain could be obtained. Difficulties in classification by serological methods can be accounted for by 1) preparation of diagnostic sera with organisms which were not sufficiently specific and 2) rapid degeneration of the strains immediately after isolation or 3) accidental transplantation of a degenerated colony in purifying the culture.