Douglas S. Kellogg

Kellogg, Douglas S., Jr. (Communicable Disease Center, Atlanta, Ga.), William L. Peacock, Jr., W. E. Deacon, L. Brown, and Carl I. Pirkle. Neisseria gonorrhoeae. I. Virulence genetically linked to clonal variation. J. Bacteriol. 85:1274-1279. 1963.-One type, obtained from the purulent exudate of acute gonorrhea was maintained by 69 selective in vitro passages, at which point the organisms produced infections in human volunteers. A predominance of clonal types found in laboratory strains and a lack of ability to infect human volunteers resulted from 69 nonselective in vitro passages. Physiological and serological characteristics of the clonal types are compared. We are now in a position to study Neisseria gonorrhoeae organisms in their virulent form.

During 35 months of selective in vitro cultivation, Neisseria gonorrhoeae cells retained their virulence for humans and were shown to be closely related to a particular colonial morphology. Saline-autoagglutinability was the only other characteristic distinguishing virulent from avirulent cells. Human responses to challenge with cells of the different colonial types were studied for their relationships to virulence or avirulence.

Direct smears from female patients have been considered unreliable for the detection of Neisseria gonorrhoeae by fluorescent-antibody (FA) methods because of inadequate background contrast of the fluorescent-stained smears and a scarcity of organisms on the smear. Evans blue dye employed as a counterstain eliminated the nonspecific background staining and increased the reliability of the direct FA procedure. Direct smears demonstrating positive fluorescence were obtained from 86% of a group of culturally positive named female contacts. The FA-counterstain technique is as sensitive as the presently recommended cultural procedures.

A method is described for cultivation of small biopsy specimens in vitro with high frequency of success. A relatively safe method for transferring and propagating cells is also described. These procedures enable investigators to establish cell lines from limited quantities of initial material. In securing cellular material from human hereditary diseases for cytological and/or biochemical investigations, these techniques may be helpful.

A method for the clinical isolation and recognition of Corynebacterium vaginale (Haemophilus vaginalis) is presented. Wet mount and stained characteristics of genital tract discharges, cellular and colonial morphology of the bacilli, inhibition by H(2)O(2), lack of a catalase, and fermentation of particular carbohydrates are the determinant factors. The method enables differentiation of the species from unclassified diphtheroids common to the genitourinary tract.