Spontaneous Agglutination of the Cholera Vibrio in Relation to Variability

Abstract

Spontaneous agglutination is a not uncommon occurrence, especially in the case of organisms of the enteric and diphtheria group, where it causes some difficulty in serological diagnosis. Many investigations have been made to clear up the principles of this phenomenon. Recently Arkwright (1921) has thrown much light on this problem. He was able to isolate from old pure cultures of dysentery, typhoid, paratyphoid and enteritidis (Gaertner) bacilli, two variants which he named the “R” (rough) and “S” (smooth). The “R” variant agglutinates spontaneously in physiological saline and in broth, while the “S” variant forms good emulsions in both. Specific immune sera prepared for these two variants show only slight cross-agglutination. Arkwright regards the two forms as potentially inherent in most of the individuals in the young culture, which may become segregated in different individuals in old cultures. “Rough” varieties have been observed also by Zoeller (1922) in B. dysenteriae Shiga and by Schütze (1921) in B. paratyphosus B.