Alpha-globulin-like antigens in bacteria.

Seventy-two strains of bacteria of the families Bacillaceae, Enterobacteriaceae and Micrococcaceae were investigated for antigens resembling Gm (1), Gm (2) and Inv (1) human immunoglobulin group factors. Antigens similar to these factors were encountered in some strains of the genus Bacillus. Staph. epidermidis strains had antigenic structures resembling Gm (1) and Inv (1) factors, and strains of Enterobacteriaceae structures resembling Gm (2) and Inv (1). Occurrence among various species of bacteria of antigens resembling human gamma-globulin group factors suggests immunization by bacterial infection as one of the causes of presence of anti-Gm and anti-Inv antibodies in human beings.